Global Mitigation of Non-CO2

Greenhouse Gases

United States Environmental Office of Atmospheric Programs (6207J) EPA 430-R-06-005 Protection Agency Washington, DC 20460 June 2006
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report, call the National Service Center for Environmental 

Publications (NSCEP) at 1 - (800) 490-9198.

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The results presented in this report can be downloaded 

in spreadsheet format from the U.S. EPA’s Web site at 

<http:/www.epa.gov/nonco2/econ-inv/international.html>. 

For additional information, contact Christa Clapp, 

(202) 343-9807, clapp.christa@epa.gov, U.S. Environmental 

Protection Agency.

Peer reviewed document

This report has undergone an external peer review consistent 

with the guidelines of the U.S. EPA Peer Review Policy. 

Comments were received from experts in the private sector, 

academia, nongovernmental organizations, and other 

government agencies. See the Acknowledgments section 

for a list of reviewers. A copy of the EPA Peer Review 

guidelines can be downloaded from the following Web 

page at <http://epa.gov/osa/spc/2peerrev.htm>.
Global Mitigation of Non-CO2

Greenhouse Gases

June 2006

United States Environmental Protection Agency 

Office of Atmospheric Programs (6207J) 

1200 Pennsylvania Ave., NW 

Washington, DC 20460

Acknowledgments

This report was prepared under a contract between the U.S. Environmental Protection 

Agency (USEPA) and RTI International (RTI). Casey Delhotal directed the preliminary 

version of the report. Christa Clapp edited and directed completion of the report. Lead 

authors include Mike Gallaher of RTI (Energy and Waste), Deborah Ottinger of USEPA 

(Industrial Fluorinated Gases), Dave Godwin of USEPA (Ozone-Depleting Substitutes), 

and Benjamin DeAngelo of USEPA (Agriculture). We thank USEPA reviewers Francisco 

de la Chesnaye, Dina Kruger, Brian Guzzone, Reid Harvey, Kurt Roos, and Tom Wirth.

Other significant contributors and co-authors include Steven Rose of USEPA, Robert 

Beach of RTI, Jochen Harnisch and Sina Wartmann of Ecofys, William Salas of Applied 

GeoSolutions, Changsheng Li of University of New Hampshire, Stephen Del Grosso of 

Colorado State University, and Timothy Sulser of International Food Policy Research 

Institute.

The staff at RTI assisted in compiling and finalizing the report. The staff at ICF Consulting 

and RTI prepared many of the individual analyses. Special recognition goes to Mike 

Gallaher and Jeffrey Petrusa at RTI and Marian Van Pelt at ICF Consulting. 

We also thank the following external reviewers: Paul Ashford (Caleb Group), Ward 

Atkinson (SAE, retired), Dave Bateman (DuPont Fluoroproducts), Steven H. Bernhardt 

(Honeywell Fluorine Products), Donald Bivens (DuPont Fluoroproducts), Eric Campbell 

(DILO Company, Inc.), Nick Campbell (Arkema), Jim Crawford (The Trane Company), 

David Crawley (Eurelectric), Hugh Crowther (McQuay International), William Dietrich 

(York), Tony Digmanese (York), Maureen Hardwick (International Pharmaceutical Aerosol 

Consortium), Jochen Harnisch (Ecofys), Susan Herrenbruck (Extruded Polystyrene Foam 

Association), Kenneth Hickman (York, retired), William Hill (General Motors), Mark 

Hudgins (Environmental Control Systems, Inc.), Andy S. Kydes (Energy Information 

Administration), Dick LaLumondier (NEMA), Stefan Lechtenböhmer (Wuppertal Institute 

for Climate, Environment, Energy), Jan Lewandrowski (USDA Office of the Chief 

Economist), Lin Erda (Chinese Academy of Agriculture Sciences), Jerry Marks (Jerry 

Marks & Associates), Archie McCulloch (Marbury Technical Consulting and University 

of Bristol, UK), Abid Merchant (DuPont), John Mutton (The Dow Chemical Company), 

Enrique Otegui (Capiel), John Owens (3M), Friedrich Plöger (Siemens), G. Philip 

Robertson (Michigan State University), J. Patrick Rynd (Owens Corning), Keith Smith 

(University of Edinburgh), Pete Smith (University of Aberdeen), Eugene Smithart 

(Danfoss Turbocor), Jerry Triplett (Partnership for Energy and Environmental Reform), 

Tom Tripp (US Magnesium), Dan Verdonik (Hughes Associates, Inc.), William Walter 

(Carrier Corporation), Thomas E. Werkema (Arkema), Kert Werner (3M), J. Jason West 

(Princeton University), Robert Wickham (Wickham Associates), and Li Yue (Chinese 

Academy of Agriculture Sciences). Although these individuals participated in the review 

of this analysis, their efforts do not constitute an endorsement of the report’s results or of 

any USEPA policies and programs.
Non-CO2_Cover_FINALrev.indd 8 8/18/06 10:27
VII

Contents 

Section Page 

 Executive Summary.....................................................................................................................ES-1 

I. Technical Summary 

I.1 Overview...........................................................................................................................................I-1

I.2 Non-CO2 Greenhouse Gases..........................................................................................................I-1

I.2.1 Methane (CH4) ................................................................................................................................ I-2

I.2.2 Nitrous Oxide (N2O) ...................................................................................................................... I-3

I.2.3 High-GWP Gases............................................................................................................................ I-4

I.2.3.1 HFCs ............................................................................................................................... I-4

I.2.3.2 PFCs................................................................................................................................ I-4

I.2.3.3 Sulfur Hexaflouride (SF6)............................................................................................. I-4

I.2.4 Use of GWPs in this Report........................................................................................................... I-5

I.3 Methodology ....................................................................................................................................I-5

I.3.1 Baseline Emissions for Non-CO2 Greenhouse Gases................................................................. I-6

I.3.1.1 Baseline Emissions for Agriculture ............................................................................ I-7

I.3.1.2 Baseline Emissions for Fluorinated Gases................................................................. I-7

I.3.2 Mitigation Option Analysis Methodology.................................................................................. I-8

I.3.2.1 Technical Characteristics of Abatement Options ..................................................... I-9

I.3.2.2 Economic Characteristics of Abatement Options................................................... I-11

I.3.3 Marginal Abatement Curves....................................................................................................... I-13

I.3.4 Methodological Enhancements from Energy Modeling Forum Study ................................. I-15

I.4 Aggregate Results.........................................................................................................................I-16

I.4.1 Baselines......................................................................................................................................... I-16

I.4.1.1 By Non-CO2 Greenhouse Gas ................................................................................... I-16

I.4.1.2 By Major Emitting Sectors and Countries ............................................................... I-17

I.4.2 Global MACs................................................................................................................................. I-19

I.5 Limitations and Applications of MACs........................................................................................I-21

I.5.1 Limitations and Uncertainties..................................................................................................... I-21

I.5.1.1 Exclusion of Transaction Costs ................................................................................. I-22

I.5.1.2 Static Approach to Abatement Assessment ............................................................ I-22

I.5.1.3 Limited Use of Regional Data ................................................................................... I-22

I.5.1.4 Exclusion of Indirect Emissions Reductions ........................................................... I-22
VIII

Section Page 

I.5.2 Practical Applications of MACs in Economic Models............................................................. I-22

I.6 References .....................................................................................................................................I-23 

Appendix 

A: Additional Information to Technical Summary ....................................................................... A-1 

II. Energy 

II.1 Coal Mining Sector .........................................................................................................................II-1

II.1.1 Introduction....................................................................................................................................II-1

II.1.2 Baseline Emissions Estimates.......................................................................................................II-2

II.1.2.1 Activity Data.................................................................................................................II-3

II.1.2.2 Emissions Factors and Related Assumptions ..........................................................II-4

II.1.2.3 Emissions Estimates and Related Assumptions ......................................................II-5

II.1.3 Cost of CH4 Emissions Reductions from Coal Mining.............................................................II-6

II.1.3.1 Abatement Option Opportunities .............................................................................II-6

II.1.4 Results .............................................................................................................................................II-9

II.1.4.1 Data Tables and Graphs..............................................................................................II-9

II.1.4.2 Uncertainties and Limitations..................................................................................II-11

II.1.5 Summary.......................................................................................................................................II-12

II.1.6 References .....................................................................................................................................II-12

II.2 Natural Gas Sector .......................................................................................................................II-15

II.2.1 Introduction..................................................................................................................................II-15

II.2.2 Baseline Emissions Estimates.....................................................................................................II-17

II.2.2.1 Activity Data...............................................................................................................II-17

II.2.2.2 Emissions Factors and Related Assumptions ........................................................II-19

II.2.2.3 Emissions Estimates and Related Assumptions ....................................................II-22

II.2.3 Cost of CH4 Emissions Reductions from Natural Gas Systems ............................................II-23

II.2.3.1 Abatement Option Opportunities ...........................................................................II-24

II.2.4 Results ...........................................................................................................................................II-26

II.2.4.1 Data Tables and Graphs............................................................................................II-26

II.2.5 Summary.......................................................................................................................................II-30

II.2.6 References .....................................................................................................................................II-30

II.3 Oil Sector.......................................................................................................................................II-31

II.3.1 Introduction..................................................................................................................................II-31
IX

Section Page 

II.3.1.1 Emissions from Production Field Operations........................................................II-32

II.3.1.2 Emissions from Crude Oil Transportation.............................................................II-32

II.3.1.3 Emissions from Crude Oil Refining ........................................................................II-32

II.3.1.4 Abatement Options....................................................................................................II-32

II.3.2 Baseline Emissions Estimates.....................................................................................................II-33

II.3.2.1 Activity Factors ..........................................................................................................II-33

II.3.2.2 Emissions Factors and Related Assumptions ........................................................II-33

II.3.2.3 Emissions Estimates and Related Assumptions ....................................................II-37

II.3.3 The Cost of CH4 Emissions Reductions from Oil....................................................................II-37

II.3.3.1 Abatement Option Opportunities ...........................................................................II-37

II.3.4 Results ...........................................................................................................................................II-40

II.3.4.1 Data Tables and Graphs............................................................................................II-40

II.3.5 Uncertainties and Limitations....................................................................................................II-40

II.3.6 Summary.......................................................................................................................................II-42

II.3.7 References .....................................................................................................................................II-42 

Appendixes 

B: Coal Mining Sector--Incorporating Technology Change to MAC Analysis.......................... B-1 

C: Natural Gas Sector--Incorporating Technology Change to MAC Analysis...........................C-1 

D: Supporting Materials for Analysis of Oil Systems................................................................... D-1 

III. Waste 

III.1 Landfill Sector ...............................................................................................................................III-1

III.1.1 Introduction.................................................................................................................................. III-1

III.1.2 Baseline Emissions Estimates..................................................................................................... III-2

III.1.2.1 Activity Data............................................................................................................... III-3

III.1.2.2 Emissions Factors and Related Assumptions ........................................................ III-3

III.1.2.3 Emissions Estimates and Related Assumptions .................................................... III-4

III.1.3 Cost of Emissions Reductions from Landfills.......................................................................... III-7

III.1.3.1 Abatement Option Opportunities ........................................................................... III-7

III.1.4 Results ........................................................................................................................................... III-9

III.1.4.1 Data Tables and Graphs............................................................................................ III-9

III.1.4.2 Uncertainties and Limitations................................................................................ III-11

III.1.5 Summary and Analysis............................................................................................................. III-12

III.1.6 References ................................................................................................................................... III-12
X

Section Page 

III.2 Wastewater Sector.......................................................................................................................III-13

III.2.1 Introduction.................................................................................................................................III-13

III.2.1.1 Emissions from Wastewater Systems.....................................................................III-14

III.2.2 Baseline Emissions Estimates....................................................................................................III-16

III.2.2.1 Activity Factors .........................................................................................................III-17

III.2.2.2 Emissions Factors and Related Assumptions .......................................................III-18

III.2.2.3 Emissions Estimates and Related Assumptions ...................................................III-18

III.2.3 Emissions Reductions from Wastewater ....................................................................................III-20

III.2.3.1 Abatement Option Opportunities ..........................................................................III-20

III.2.3.2 Uncertainties and Limitations.................................................................................III-22

III.2.4 Summary......................................................................................................................................III-22

III.2.5 References ....................................................................................................................................III-22

Appendix 

E: MSW Landfill Sector—Incorporating Technology Change to MAC Analysis...................... E-1 

IV. Industrial Processes 

IV.1 N2O Emissions from Nitric and Adipic Acid Production .......................................................... IV-1

IV.1.1 Introduction.................................................................................................................................. IV-1

IV.1.1.1 Nitric Acid .................................................................................................................. IV-2

IV.1.1.2 Adipic Acid................................................................................................................. IV-2

IV.1.2 Baseline Emissions Estimates..................................................................................................... IV-2

IV.1.2.1 Activity Factors .......................................................................................................... IV-2

IV.1.2.2 Emissions Factors and Related Assumptions ........................................................ IV-4

IV.1.2.3 Emissions Estimates and Related Assumptions .................................................... IV-5

IV.1.3 Cost of N2O Emissions Reductions from Industrial Processes ............................................. IV-6

IV.1.3.1 Nitric Acid: N2O Abatement Option Opportunities............................................. IV-7

IV.1.3.2 Adipic Acid: N2O Abatement Option Opportunities ........................................... IV-8

IV.1.4 Results ........................................................................................................................................... IV-8

IV.1.4.1 Data Tables and Graphs............................................................................................ IV-8

IV.1.4.2 Uncertainties and Limitations.................................................................................. IV-8

IV.1.5 Summary..................................................................................................................................... IV-12

IV.1.6 References ................................................................................................................................... IV-12
XI

Section Page 

IV.2 HFC Emissions from Refrigeration and Air-Conditioning...................................................... IV-15

IV.2.1 Introduction................................................................................................................................ IV-15

IV.2.1.1 Household Refrigeration ........................................................................................ IV-15

IV.2.1.2 Motor Vehicle Air-Conditioning (MVAC) ........................................................... IV-16

IV.2.1.3 Chillers ...................................................................................................................... IV-16

IV.2.1.4 Retail Food Refrigeration........................................................................................ IV-17

IV.2.1.5 Cold Storage Warehouses....................................................................................... IV-17

IV.2.1.6 Refrigerated Transport............................................................................................ IV-17

IV.2.1.7 Industrial Process Refrigeration ............................................................................ IV-18

IV.2.1.8 Residential and Small Commercial Air-Conditioning and Heat Pumps ......... IV-18

IV.2.2 Baseline Emissions Estimates................................................................................................... IV-18

IV.2.2.1 Emissions Estimating Methodology...................................................................... IV-18

IV.2.2.2 Baseline Emissions................................................................................................... IV-24

IV.2.3 Cost of HFC Emissions Reduction from Refrigeration and Air-Conditioning ................. IV-25

IV.2.3.1 Description and Cost Analysis of Abatement Options....................................... IV-25

IV.2.3.2 Summary of Technical Applicability, Market Penetration, and Costs of 

Abatement Options ................................................................................................. IV-45

IV.2.4 Results ......................................................................................................................................... IV-45

IV.2.4.1 Data Tables and Graphs.......................................................................................... IV-46

IV.2.4.2 Uncertainties and Limitations................................................................................ IV-54

IV.2.5 Summary..................................................................................................................................... IV-54

IV.2.6 References ................................................................................................................................... IV-55

IV.3 HFC, HFE, and PFC Emissions from Solvents ........................................................................ IV-59

IV.3.1 Introduction................................................................................................................................ IV-59

IV.3.2 Baseline Emissions Estimates................................................................................................... IV-60

IV.3.2.1 Emissions Estimating Methodology...................................................................... IV-60

IV.3.2.2 Baseline Emissions................................................................................................... IV-61

IV.3.3 Cost of HFC, HFE, and PFC Emissions Reductions for Solvents........................................ IV-62

IV.3.3.1 Description and Cost Analysis of Abatement Options....................................... IV-62

IV.3.3.2 Summary of Technical Applicability, Market Penetration, and Costs of 

Abatement Options ................................................................................................. IV-67

IV.3.4 Results ......................................................................................................................................... IV-68

IV.3.4.1 Data Tables and Graphs.......................................................................................... IV-68

IV.3.4.2 Uncertainties and Limitations................................................................................ IV-71
XII

Section Page 

IV.3.5 Summary..................................................................................................................................... IV-71

IV.3.6 References ................................................................................................................................... IV-72

IV.4 HFC Emissions from Foams...................................................................................................... IV-75

IV.4.1 Introduction................................................................................................................................ IV-75

IV.4.2 Baseline Emissions Estimates................................................................................................... IV-76

IV.4.2.1 Emissions Estimating Methodology...................................................................... IV-76

IV.4.2.2 Baseline Emissions................................................................................................... IV-79

IV.4.3 Cost of HFC Emissions Reductions from Foams................................................................... IV-81

IV.4.3.1 Abatement Options ................................................................................................. IV-81

IV.4.3.2 Description and Costs of Abatement Options ..................................................... IV-83

IV.4.3.3 Summary of Technical Applicability, Market Penetration, and Costs of 

Abatement Options ................................................................................................. IV-90

IV.4.4 Results ......................................................................................................................................... IV-91

IV.4.4.1 Data Tables and Graphs.......................................................................................... IV-91

IV.4.4.2 Uncertainties and Limitations................................................................................ IV-91

IV.4.5 Summary..................................................................................................................................... IV-99

IV.4.6 References ................................................................................................................................. IV-100

IV.5 HFC Emissions from Aerosols................................................................................................ IV-103

IV.5.1 Introduction.............................................................................................................................. IV-103

IV.5.2 Baseline Emissions Estimates................................................................................................. IV-103

IV.5.2.1 Emissions Estimating Methodology.................................................................... IV-103

IV.5.2.2 Baseline Emissions................................................................................................. IV-105

IV.5.3 Cost of HFC Emissions Reductions for Aerosols ................................................................ IV-105

IV.5.3.1 Description and Cost Analysis of Abatement Options..................................... IV-105

IV.5.3.2 Summary of Technical Applicability, Market Penetration, and Costs of 

Abatement Options ............................................................................................... IV-110

IV.5.4 Results ....................................................................................................................................... IV-111

IV.5.4.1 Data Tables and Graphs........................................................................................ IV-111

IV.5.4.2 Uncertainties and Limitations.............................................................................. IV-116

IV.5.5 Summary................................................................................................................................... IV-116

IV.5.5.1 MDI Aerosols ......................................................................................................... IV-117

IV.5.5.2 Non-MDI Aerosols ................................................................................................ IV-117

IV.5.6 References ................................................................................................................................. IV-117
XIII

Section Page 

IV.6 HFC Emissions from Fire Extinguishing................................................................................ IV-119

IV.6.1 Introduction.............................................................................................................................. IV-119

IV.6.2 Baseline Emissions Estimates................................................................................................. IV-121

IV.6.2.1 Emissions Estimating Methodology.................................................................... IV-121

IV.6.2.2 Baseline Emissions................................................................................................. IV-122

IV.6.3 Cost of HFC Emissions Reductions from Fire Extinguishing............................................ IV-124

IV.6.3.1 Description and Cost Analysis of Abatement Options..................................... IV-124

IV.6.3.2 Summary of Technical Applicability, Market Penetration, and Costs of 

Abatement Options ............................................................................................... IV-130

IV.6.4 Results ....................................................................................................................................... IV-133

IV.6.4.1 Data Tables and Graphs........................................................................................ IV-133

IV.6.4.2 Uncertainties and Limitations.............................................................................. IV-136

IV.6.5 Summary................................................................................................................................... IV-136

IV.6.6 References ................................................................................................................................. IV-136

IV.7 PFC Emissions from Aluminum Production.......................................................................... IV-139

IV.7.1 Technology-Adoption Baseline ............................................................................................. IV-139

IV.7.2 No-Action Baseline.................................................................................................................. IV-141

IV.7.3 Cost of PFC Emissions Reduction from Aluminum Production....................................... IV-142

IV.7.3.1 Abatement Options ............................................................................................... IV-142

IV.7.4 Results ....................................................................................................................................... IV-146

IV.7.4.1 Data Tables and Graphs........................................................................................ IV-146

IV.7.4.2 Global and Regional MACs and Analysis.......................................................... IV-149

IV.7.4.3 Uncertainties and Limitations.............................................................................. IV-151

IV.7.5 References ................................................................................................................................. IV-152

IV.8 HFC-23 Emissions from HCFC-22 Production....................................................................... IV-155

IV.8.1 Source Description................................................................................................................... IV-155

IV.8.1.2 No-Action Baseline................................................................................................ IV-156

IV.8.1.3 Technology-Adoption Baseline............................................................................ IV-158

IV.8.2 Cost of HFC-23 Reduction from HCFC-22 Production ...................................................... IV-159

IV.8.2.1 Abatement Options ............................................................................................... IV-159

IV.8.3 Results ....................................................................................................................................... IV-162

IV.8.3.1 Data Tables and Graphs........................................................................................ IV-162

IV.8.3.2 Global and Regional MACs and Analysis.......................................................... IV-165

IV.8.3.3 Uncertainties and Limitations.............................................................................. IV-167
XIV

Section Page 

IV.8.4 References ................................................................................................................................. IV-168

IV.9 PFC and SF6 Emissions from Semiconductor Manufacturing............................................. IV-169

IV.9.1 Source Description................................................................................................................... IV-169

IV.9.1.1 Technology-Adoption Baseline............................................................................ IV-170

IV.9.1.2 No-Action Baseline................................................................................................ IV-172

IV.9.2 Cost of PFC and SF6 Emissions Reduction from Semiconductor Manufacturing .......... IV-173

IV.9.2.1 Abatement Options ............................................................................................... IV-173

IV.9.3 Results ....................................................................................................................................... IV-179

IV.9.3.1 Data Tables and Graphs........................................................................................ IV-179

IV.9.3.2 Global and Regional MACs and Analysis.......................................................... IV-179

IV.9.3.3 Uncertainties and Limitations.............................................................................. IV-183

IV.9.4 References ................................................................................................................................. IV-185

IV.10 SF6 Emissions from Electric Power Systems........................................................................ IV-187

IV.10.1 Source Description................................................................................................................... IV-187

IV.10.1.1 Technology-Adoption Baseline............................................................................ IV-188

IV.10.1.2 No-Action Baseline................................................................................................ IV-189

IV.10.2 Cost of SF6 Emissions Reduction from Electric Power Systems........................................ IV-190

IV.10.2.1 Abatement Options ............................................................................................... IV-190

IV.10.3 Results ....................................................................................................................................... IV-195

IV.10.3.1 Data Tables and Graphs........................................................................................ IV-195

IV.10.3.2 Global and Regional MACs and Analysis.......................................................... IV-198

IV.10.3.3 Uncertainties and Limitations.............................................................................. IV-199

IV.10.4 References ................................................................................................................................. IV-202

IV.11 SF6 Emissions from Magnesium (Mg) Production................................................................ IV-205

IV.11.1 Source Description................................................................................................................... IV-205

IV.11.1.1 Technology-Adoption Baseline............................................................................ IV-205

IV.11.1.2 No-Action Baseline................................................................................................ IV-207

IV.11.2 Cost of SF6 Emissions Reduction from Mg Production and Processing Operations...... IV-208

IV.11.2.1 Abatement Options ............................................................................................... IV-208

IV.11.3 Results ....................................................................................................................................... IV-210

IV.11.3.1 Data Tables and Graphs........................................................................................ IV-210

IV.11.3.2 Global and Regional MACs and Analysis.......................................................... IV-213

IV.11.3.3 Uncertainties and Limitations.............................................................................. IV-215

IV.11.4 References ................................................................................................................................. IV-216
XV

Section Page 

Appendixes: 

F: Cost and Emissions Reduction Analysis for Options to Abate International HFC 

Emissions from Refrigeration and Air-Conditioning ............................................................... F-1 

G: Cost and Emissions Reduction Analysis for Options to Abate International HFC, 

HFE, and PFC Emissions from Solvents.....................................................................................G-1 

H: Cost and Emissions Reduction Analysis for Options to Abate International HFC 

Emissions from Foams ................................................................................................................. H-1 

I: Cost and Emissions Reduction Analysis for Options to Abate International HFC 

Emissions from Aerosols ............................................................................................................... I-1 

J: Cost and Emissions Reduction Analysis for Options to Abate International HFC 

Emissions from Fire Extinguishing .............................................................................................. J-1 

K: Cost and Emissions Reduction Analysis for Options in Aluminum Production .................K-1 

L: Cost and Emissions Reduction Analysis for Options in HCFC-22 Production..................... L-1 

M: Cost and Emissions Reduction Analysis for Options in Semiconductor 

Manufacturing ..............................................................................................................................M-1 

N: Cost and Emissions Reduction Analysis for Options in Electric Power Systems................ N-1 

O: Cost and Emissions Reduction Analysis for Options in Magnesium Production ............... O-1 

V. Agriculture

V.1 Introduction and Background ...................................................................................................... V-1

V.1.1 Brief Points of Comparison with Other Non-CO2 Emissions Sectors ....................................V-2

V.1.2 Previous Estimates for EMF-21 and New Improvements........................................................V-2

V.2 Emissions Characterization, Baselines, and Mitigation Scenarios.......................................... V-5

V.2.1 Croplands (N2O and Soil Carbon)...............................................................................................V-5

V.2.1.1 Cropland N2O and Soil Carbon Emissions Characterization ................................V-5

V.2.1.2 DAYCENT Baseline Estimates of Cropland N2O, Soil Carbon, and Yields.........V-6

V.2.1.3 Mitigation Options for Cropland N2O and Soil Carbon Emissions......................V-8

V.2.1.4 DAYCENT Results for Changes in Cropland N2O, Soil Carbon, and 

Yields ...........................................................................................................................V-10

V.2.2 Rice (CH4, N2O, and Soil Carbon) .............................................................................................V-12

V.2.2.1 Rice CH4, N2O, and Carbon Emissions Characterization.....................................V-12

V.2.2.2 DNDC Baseline Estimates of Rice CH4, N2O, Soil Carbon, and Yields..............V-13

V.2.2.3 Mitigation Options for Rice CH4, N2O, and Soil Carbon Emissions...................V-16

V.2.2.4 DNDC Estimates for Changes in Rice CH4, N2O, Soil Carbon, and Yields .......V-17

V.2.3 Livestock (CH4 and N2O) ...........................................................................................................V-20

V.2.3.1 Livestock Enteric CH4 Emissions Characterization ..............................................V-20
XVI

V.2.3.2 Livestock Manure CH4 and N2O Emissions Characterization ............................V-20

V.2.3.3 The USEPA Baseline Estimates of Livestock Enteric CH4 Emissions.................V-21

V.2.3.4 The USEPA Baseline Estimates of Livestock Manure CH4 and N2O 

Emissions ....................................................................................................................V-21

V.2.3.5 Mitigation Options for Livestock Emissions..........................................................V-21

V.2.3.6 Changes in Livestock CH4 and Productivity .........................................................V-26

V.3 Results.......................................................................................................................................... V-31

V.3.1 Estimating Average Costs and Constructing Abatement Curves.........................................V-31

V.3.2 Baselines, Mitigation Costs and MACs for Croplands ...........................................................V-32

V.3.3 Baselines, Mitigation Costs, and MACs for Rice Cultivation ................................................V-41

V.3.4 Baselines, Mitigation Costs, and MACs for Livestock Management....................................V-45

V.3.5 Baselines, Mitigation Costs, and MACs for Total Agriculture ..............................................V-55

V.3.6 Agricultural Commodity Market Impacts of Adopting Mitigation Options: Use of 

the IMPACT Model .....................................................................................................................V-57

V.4 Conclusions ................................................................................................................................. V-65

V.5 References ................................................................................................................................... V-69

Appendixes: 

P: Summary of Non-CO2 Agricultural Mitigation Analysis Completed for EMF-21 ............... P-1 

Q: DAYCENT Model Description and Methods ........................................................................... Q-1 

R: DNDC Model Description and Methods....................................................................................R-1 

S: Baseline Differences and Methods for This Mitigation Analysis............................................ S-1 

T: IMPACT Commodity Price Data.................................................................................................T-1 

U: Detailed Data Tables .................................................................................................................... U-1 
XVII

List of Figures 

Number Page

Section I 

2-1 Contribution of Anthropogenic Emissions of Greenhouse Gases to the Enhanced 

Greenhouse Effect from Preindustrial to Present (measured in watts/meter2) ............................. I-2

3-1 Illustrative Non-CO2 Marginal Abatement Curve .......................................................................... I-13

4-1 Percentage Share of Global Non-CO2 Emissions by Type of Gas in 2005.................................... I-16

4-2 Non-CO2 Global Emissions Forecast to 2020 by Greenhouse Gas ................................................ I-17

4-3 Global Emissions by Major Sector for All Non-CO2 Greenhouse Gases...................................... I-18

4-4 Projected World Emissions Baselines for Non-CO2 Greenhouse Gases, Including the 

Top Emitting Regions.......................................................................................................................... I-18

4-5 Global 2020 MACs for Non-CO2 Greenhouse Gases by Major Sector.......................................... I-19

4-6 Global 2020 MACs by Non-CO2 Greenhouse Gas Type................................................................. I-20

4-7 Global 2020 MACs for Non-CO2 Greenhouse Gases by Major Emitting Regions...................... I-20

Section II 

1-1 CH4 Emissions from Coal Mining, by Country: 2000–2020 ............................................................II-1

1-2 EMF MACs for Top Five Emitting Countries/Regions from Coal: 2020 .....................................II-11

2-1 CH4 from Natural Gas Systems by Country: 2000–2020 ...............................................................II-15

2-2 EMF MACs for Top Five Emitting Countries/Regions from Natural Gas: 2020 ........................II-29

3-1 CH4 Emissions from Oil Production by Country: 2000–2020 .......................................................II-31

3-2 EMF MACs for Top Five Emitting Countries/Regions from Oil: 2020........................................II-42

Section III 

1-1 CH4 Emissions from Municipal Solid Waste by Country: 2000–2020 ..........................................III-1

1-2 Components of CH4 Emissions from Landfills................................................................................III-5

1-3 EMF MACs for Top Five Emitting Countries/Regions from Landfills: 2020.............................III-11

2-1 CH4 Emissions from Wastewater by Country: 2000–2020 ...........................................................III-13

2-2 N2O Emissions from Wastewater by Country: 2000–2020 ...........................................................III-14

Section IV 

1-1 N2O Emissions from Industrial Production by Country: 2000–2020 ........................................... IV-1

1-2 EMF MACs for Top Five Emitting Country/Regions from Nitric Acid Production: 2020...... IV-11

1-3 EMF MACs for Top Five Emitting Country/Regions from Adipic Acid Production: 2020.... IV-11

2-1 Baseline HFC Emissions from Refrigeration and Air-Conditioning by Region 

(MtCO2eq).......................................................................................................................................... IV-27

2-2 2010 MAC for Refrigeration/Air-Conditioning, 10% Discount Rate, 40% Tax Rate................ IV-53

2-3 2020 MAC for Refrigeration/Air-Conditioning, 10% Discount Rate, 40% Tax Rate................ IV-54

3-1 Total Baseline HFC, PFC, and HFE Emissions Estimates from Solvents (MtCO2eq) .............. IV-63
XVIII

Number Page

3-2 2010 MAC for Solvents, 10% Discount Rate, 40% Tax Rate ........................................................ IV-70

3-3 2020 MAC for Solvents, 10% Discount Rate, 40% Tax Rate ........................................................ IV-71

4-1 Total Baseline Emissions Estimates for Foams (MtCO2eq) ......................................................... IV-80

4-2 2010 MAC for Foams, 10% Discount Rate, 40% Tax Rate ........................................................... IV-99

4-3 2020 MAC for Foams, 10% Discount Rate, 40% Tax Rate ........................................................... IV-99

5-1 Total Baseline HFC Emissions Estimates from MDI Aerosols (MtCO2eq) ............................. IV-106

5-2 Total Baseline HFC Emissions Estimates from Non-MDI Aerosols (MtCO2eq) .................... IV-107

5-3 2010 MAC for MDI Aerosols, 10% Discount Rate, 40% Tax Rate ............................................ IV-114

5-4 2020 MAC for MDI Aerosols, 10% Discount Rate, 40% Tax Rate ............................................ IV-115

5-5 2010 MAC for Non-MDI Aerosols, 10% Discount Rate, 40% Tax Rate ................................... IV-115

5-6 2020 MAC for Non-MDI Aerosols, 10% Discount Rate, 40% Tax Rate ................................... IV-116

6-1 Baseline HFC Emissions from Fire Extinguishing by Region (MtCO2eq)............................... IV-123

6-2 2010 MAC for Fire Extinguishing, 10% Discount Rate, 40% Tax Rate .................................... IV-135

6-3 2020 MAC for Fire Extinguishing, 10% Discount Rate, 40% Tax Rate .................................... IV-135

7-1 PFC Emissions from Aluminum Production Based on a Technology-Adoption 

Scenario—1990−2020 (MtCO2eq).................................................................................................. IV-141

7-2 PFC Emissions from Aluminum Production Based on a No-Action Scenario—1990–

2020 (MtCO2eq)............................................................................................................................... IV-142

7-3 2010 and 2020 Global Technology-Adoption and No-Action MACs for Primary 

Aluminum Production................................................................................................................... IV-150

7-4 2010 Regional Technology-Adoption MACs for Primary Aluminum Production................ IV-150

7-5 2020 Regional Technology-Adoption MACs for Primary Aluminum Production................ IV-151

8-1 HFC-23 Emissions from HCFC-22 Production Based on a No-Action Scenario—1990–

2020 (MtCO2eq)............................................................................................................................... IV-157

8-2 HFC-23 Emissions from HCFC-22 Production Based on a Technology-Adoption 

Scenario—1990–2020 (MtCO2eq) .................................................................................................. IV-158

8-3 2010 and 2020 Global Technology-Adoption and No-Action MACs for HCFC-22 

Production ....................................................................................................................................... IV-165

8-4 2010 Regional Technology-Adoption MACs .............................................................................. IV-166

8-5 2020 Regional Technology-Adoption MACs .............................................................................. IV-166

9-1 PFC Emissions from Semiconductor Manufacturing Based on a Technology-Adoption 

Scenario—1990 through 2020 (MtCO2eq).................................................................................... IV-171

9-2 WSC and Non-WSC Countries’ Contribution to Global PFC Emissions (MtCO2eq)............ IV-171

9-3 PFC Emissions from Semiconductor Manufacturing Based on a No-Action Scenario—

1990 through 2020 (MtCO2eq)....................................................................................................... IV-173

9-4 2010 Regional Technology-Adoption MACs for Semiconductor Manufacturing ................. IV-184

9-5 2020 Regional Technology-Adoption MACs for Semiconductor Manufacturing ................. IV-184

10-1 SF6 Emissions from Electric Power Systems on a Technology-Adoption Scenario—

1990–2020 (MtCO2eq) ..................................................................................................................... IV-189

10-2 SF6 Emissions from Electric Power Systems on a No-Action Scenario—1990–2020 

(MtCO2eq)........................................................................................................................................ IV-190

10-3 2010 and 2020 Global Technology-Adoption and No-Action MACs for Electric Power 

Systems............................................................................................................................................. IV-198

10-4 2010 Regional Technology-Adoption MACs for Electric Power Systems............................... IV-200
XIX

Number Page

10-5 2020 Regional Technology-Adoption MACs for Electric Power Systems............................... IV-200

11-1 SF6 Emissions from Mg Manufacturing Based on a Technology-Adoption Scenario—

1990–2020 (MtCO2eq)..................................................................................................................... IV-207

11-2 SF6 Emissions from Mg Manufacturing Based on a No-Action Scenario—1990–2020 

(MtCO2eq)........................................................................................................................................ IV-208

11-3 2010 and 2020 Global Technology-Adoption and No-Action MACs for Mg Production..... IV-213

11-4 2010 Regional Technology-Adoption MACs .............................................................................. IV-214

11-5 2020 Regional Technology-Adoption MACs .............................................................................. IV-214

Section V 

1-1 Global Cropland Yields for Baseline and Mitigation Options Estimated by DAYCENT, 

2010 .......................................................................................................................................................V-10 

1-2 Global Net Greenhouse Gas (N2O and Soil Carbon) Cropland Emissions Estimated by 

DAYCENT under Baseline and Mitigation Scenarios ...................................................................V-11

1-3 Global Net Greenhouse Gas (CH4 and N2O) Livestock Emissions under Baseline and 

Mitigation Scenarios, Assuming Full Adoption of Individual Options and Holding 

Number of Animals Constant ...........................................................................................................V-26

1-4 Global Net Greenhouse Gas (CH4 and N2O) Livestock Emissions under Baseline and 

Mitigation Scenarios, Assuming Full Adoption of Individual Options and Holding 

Production Constant...........................................................................................................................V-27

1-5 Global Beef Production under Baseline and Mitigation Options, Assuming Full 

Adoption of Individual Options and Holding the Number of Animals Constant....................V-28

1-6 Global Production of Milk from Dairy Cattle under Baseline and Mitigation Options, 

Assuming Full Adoption of Individual Options and Holding the Number of Animals 

Constant ...............................................................................................................................................V-28

1-7 Global MAC for Net Greenhouse Gas Emissions from Croplands, Holding Area 

Constant, 2000–2020 ...........................................................................................................................V-37

1-8 Global MAC for Net Greenhouse Gas Emissions from Croplands, Holding Area 

Constant, Allocating Adoption of Mitigation Strategies to the Three Most Effective 

Options Only, 2000–2020 ...................................................................................................................V-38

1-9 MAC for Net Greenhouse Gas Emissions from Cropland Management in the United 

States, Holding Area Constant, 2000–2020......................................................................................V-39

1-10 MAC for Net Greenhouse Gas Emissions from Cropland Management in the EU-15, 

Holding Area Constant, 2000–2020 ..................................................................................................V-39

1-11 MAC for Net Greenhouse Gas Emissions from Cropland Management in the FSU, 

Holding Area Constant, 2000–2020 ..................................................................................................V-40

1-12 MAC for Net Greenhouse Gas Emissions from Cropland Management in China, 

Holding Area Constant, 2000–2020 ..................................................................................................V-40

1-13 Global MAC for Net Greenhouse Gas Emissions from Rice Cultivation, Holding Area 

Constant, 2000–2020 ...........................................................................................................................V-43

1-14 MAC for Net Greenhouse Gas Emissions from Rice Cultivation in India, Holding Area 

Constant, 2000–2020 ...........................................................................................................................V-44

1-15 MAC for Net Greenhouse Gas Emissions from Rice Cultivation in China, Holding Area 

Constant, 2000–2020 ...........................................................................................................................V-44
XX

Number Page

1-16 Global MAC for Greenhouse Gas Emissions from Livestock Management, Holding 

Number of Animals Constant, 2000–2020 .......................................................................................V-50

1-17 Global MAC for Greenhouse Gas Emissions from Livestock Management, Holding 

Production Constant, 2000–2020.......................................................................................................V-50

1-18 MAC for Greenhouse Gas Emissions from Livestock Management in the United States, 

Holding Number of Animals Constant, 2000–2020 .......................................................................V-51

1-19 MAC for Greenhouse Gas Emissions from Livestock Management in China, Holding 

Number of Animals Constant, 2000–2020 .......................................................................................V-51

1-20 MAC for Greenhouse Gas Emissions from Livestock Management in India, Holding 

Number of Animals Constant, 2000–2020 .......................................................................................V-52

1-21 MAC for Greenhouse Gas Emissions from Livestock Management in Brazil, Holding 

Number of Animals Constant, 2000–2020 .......................................................................................V-52

1-22 MAC for Greenhouse Gas Emissions from Livestock Management in the United States, 

Holding Production Constant, 2000–2020 .......................................................................................V-53

1-23 MAC for Greenhouse Gas Emissions from Livestock Management in China, Holding 

Production Constant, 2000–2020.......................................................................................................V-53

1-24 MAC for Greenhouse Gas Emissions from Livestock Management in India, Holding 

Production Constant, 2000–2020.......................................................................................................V-54

1-25 MAC for Greenhouse Gas Emissions from Livestock Management in Brazil, Holding 

Production Constant, 2000–2020.......................................................................................................V-54

1-26 Global MAC for Net Greenhouse Gas Emissions from Agriculture, Holding 

Area/Animals Constant, 2000–2020..................................................................................................V-56

1-27 Global MAC for Net Greenhouse Gas Emissions from Agriculture, Holding Production 

Constant, 2000–2020 ...........................................................................................................................V-57

1-28 Effect of Global Adoption of the Antimethanogen Vaccine Mitigation Option on World 

Prices Using the IMPACT Model .....................................................................................................V-58

1-29 Effect of Global Adoption of the Antimethanogen Vaccine Mitigation Option on Global 

Production Using the IMPACT Model ............................................................................................V-59

1-30 Effect of Global Adoption of the Antimethanogen Vaccine Mitigation Option on Global 

Number of Animals Using the IMPACT Model.............................................................................V-59 

1-31 Effect of Global Adoption of the Shallow Flooding Mitigation Option on World Prices 

Using the IMPACT Model.................................................................................................................V-61 

1-32 Effect of Global Adoption of the Shallow Flooding Mitigation Option on Global 

Production Using the IMPACT Model ............................................................................................V-61

1-33 Effect of Global Adoption of the Shallow Flooding Mitigation Option on Global Rice 

Area Using the IMPACT Model .......................................................................................................V-62

1-34 Net GHG Abatement under Global Adoption of the Antimethanogen Vaccine Option 

with Number of Cattle Constant, Production Constant, and Market Adjustments Using 

the IMPACT Model, 2010 ..................................................................................................................V-62

1-35 Comparison of Net GHG Abatement from Rice Cultivation under Global Adoption of 

the Shallow Flooding Mitigation Option with Area Constant, Production Constant, and 

Market Adjustments Using the IMPACT Model, 2010..................................................................V-63
XXI

List of Tables 

Number Page

Section I

2-1 Global Greenhouse Gas (GHG) Emissions for 2000 (MtCO2eq)...................................................... I-2

2-2 Global Warming Potentials .................................................................................................................. I-5

3-1 Abatement Potential Calculation for Mitigation Options .............................................................. I-10

3-2 Financial Assumptions in Breakeven Price Calculations for Abatement Options...................... I-13

Section II 

1-1 Historical Coal Mining Activity Data for Selected Countries (Million Metric Tons) ..................II-4

1-2 IPCC Suggested Underground Emissions Factors for Selected Countries ...................................II-5

1-3 Historical Baseline Emissions for Coal Mine CH4 for Selected Countries (MtCO2eq)................II-5

1-4 Projected Baseline Emissions for Coal Mine CH4 for Selected Countries (MtCO2eq).................II-6

1-5 Summary of Average Abatement Costs and Benefits for U.S. Coal Mines (in 2000$).................II-7

1-6 Summary of Coal Mining Abatement Options Included in the Analysis.....................................II-9

1-7 Baseline Emissions by EMF Regional Grouping: 2000–2020 (MtCO2eq) ....................................II-10

1-8 Coal Mining MACs for Countries Included in the Analysis.........................................................II-10

2-1 Natural Gas Industry Characterization ...........................................................................................II-16

2-2 Natural Gas Production by Country and Region: 1980–2003 (Trillion Cubic Feet)...................II-18

2-3 Natural Gas Consumption by Country and Region: 1980–2003 (Trillion Cubic Feet) ..............II-19

2-4 Projected Natural Gas Production by Country and Region: 2010–2025 (Trillion Cubic 

Feet) ......................................................................................................................................................II-20

2-5 Projected Natural Gas Consumption by Country and Region: 2010–2025 (Trillion Cubic 

Feet) ......................................................................................................................................................II-20

2-6 IPCC Estimated Emissions Factors from Natural Gas by Region................................................II-21

2-7 Baseline Emissions for Natural Gas Systems for Selected Countries: 1990–2000 

(MtCO2eq)............................................................................................................................................II-21

2-8 Projected Baseline Emissions for Natural Gas Systems for Selected Countries: 2005–

2020 (MtCO2eq)...................................................................................................................................II-23

2-9 Prevalence of Abatement Options by Infrastructure Component ...............................................II-23

2-10 Natural Gas MACs for Countries Included in the Analysis .........................................................II-27

2-11 Baseline Emissions by EMF Regional Grouping: 2000–2020 (MtCO2eq) ....................................II-28

2-12 Natural Gas MACs for Countries Included in the Analysis .........................................................II-29

3-1 Oil Production by Country: 1990–2003 (MMbbl per Day) ............................................................II-34

3-2 Forecasted Oil Production for Selected Countries (MMbbl per Day, Unless Otherwise 

Noted)...................................................................................................................................................II-35

3-3 Forecasted Oil Consumption for Selected Countries (MMbbl per Day, Unless 

Otherwise Noted) ...............................................................................................................................II-36

3-4 IPCC Emissions Factors for Petroleum Systems in Select Regions ..............................................II-37

3-5 Baseline Emissions from Oil Production, by Country: 1990–2000 (MtCO2eq) ...........................II-38

3-6 Projected Baseline Emissions from Oil Production by Country: 2005–2020 (MtCO2eq)...........II-38

3-7 Cost of Reducing CH4 Emissions from Oil......................................................................................II-39
XXII

Number Page

3-8 Percentage Abatement for CH4 for Selected Breakeven Price ($/tCO2eq): 2000.........................II-40

3-9 Baseline Emissions by EMF Regional Grouping: 2000-2020 (MtCO2eq).....................................II-41

3-10 Oil System MACs for Countries Included in the Analysis ...........................................................II-41

Section III 

1-1 CH4 Emissions from Municipal Solid Waste by Country: 1990–2000 (MtCO2eq) ......................III-5

1-2 Projected Baseline CH4 Emissions from Municipal Solid Waste by Country: 2005–2020 

(MtCO2eq).............................................................................................................................................III-6

1-3 Components of Collection and Flaring and LFG Utilization Abatement Options .....................III-7

1-4 Breakeven Prices of MSW Landfill Technology Options ...............................................................III-9

1-5 Baseline Emissions by EMF Regional Grouping: 2000–2020 (MtCO2eq) ...................................III-10

1-6 MSW Landfill MACs for Countries Included in the Analysis.....................................................III-10

2-1 CH4 Emissions from Wastewater by Country: 1990–2000 (MtCO2eq) .......................................III-19

2-2 N2O Emissions from Wastewater by Country: 1990–2000 (MtCO2eq).......................................III-19

2-3 Projected Baseline CH4 Emissions from Wastewater by Country: 2005–2020 (MtCO2eq) ......III-21

2-4 Projected Baseline N2O Emissions from Wastewater by Country: 2005–2020 (MtCO2eq) ......III-21

Section IV 

1-1 2003 Adipic Acid Production Capacity (Thousands of Metric Tons/Year)................................. IV-3

1-2 IPCC Emissions Factors for Nitric Acid Production in Select Countries .................................... IV-4

1-3 N2O Emissions from Nitric and Adipic Acid Production: 1990–2000 (MtCO2eq)..................... IV-5

1-4 Projected N2O Baseline Emissions from Nitric and Adipic Acid Production: 2005–2020 

(MtCO2eq)............................................................................................................................................ IV-6

1-5 Cost of Reducing N2O Emissions from Industrial Processes........................................................ IV-7

1-6 Projected N2O Emissions from Nitric Acid by Region: 2000–2020 (MtCO2eq) .......................... IV-9

1-7 Percentage Abatement for Nitric Acid for Selected Breakeven Prices ($/tCO2eq): 2010–

2020 ....................................................................................................................................................... IV-9

1-8 Projected N2O Emissions from Adipic Acid by Region: 2000–2020 (MtCO2eq) ...................... IV-10

1-9 Percentage Abatement for Adipic Acid for Selected Breakeven Prices ($/tCO2eq): 2010–

2020 ..................................................................................................................................................... IV-10

2-1 Reductions in Baseline Emissions in Non-U.S. Countries to Reflect Market Adjustments .... IV-21

2-2 Estimated Percentage of GWP-Weighted Refrigeration and Air-Conditioning HFC 

Emissions Attributo MVACs in the United States ....................................................................... IV-22

2-3 Percentage of Newly Manufactured Vehicles Assumed to Have Operational AirConditioning Units in India ............................................................................................................ IV-22

2-4 Percentage of Newly Manufactured Vehicles Assumed to Have Operational AirConditioning Units in All Other Countries................................................................................... IV-23

2-5 Estimated Percentage of Refrigeration and Air-Conditioning HFC Emissions Attributo 

MVACs............................................................................................................................................... IV-24

2-6 Distribution of Refrigeration- and Air-Conditioning–Sector HFC Emissions by EndUse, Region, and Year (Percent) ..................................................................................................... IV-26

2-7 Total Baseline HFC Emissions from Refrigeration and Air-Conditioning (MtCO2eq) ........... IV-27

2-8 Assumptions on Duration and Applicability of Emissions Reduction Options ...................... IV-29
XXIII

Number Page

2-9 Summary of Assumptions for Leak Repair for Large Equipment ............................................. IV-32

2-10 Summary of Assumptions for Recovery and Recycling from Small Equipment..................... IV-33

2-11 Summary of Assumptions for Distributed Systems for New Stationary Equipment ............. IV-37

2-12 Summary of Assumptions for HFC Secondary Loop Systems for New Stationary 

Equipment ......................................................................................................................................... IV-38

2-13 Summary of Assumptions for Ammonia Secondary Loop Systems for New Stationary 

Equipment ......................................................................................................................................... IV-39

2-14 Summary of Assumptions for Enhanced HFC-134a Systems for New MVACs...................... IV-40

2-15 Summary of Assumptions for HFC-152a DX Systems in New MVACs ................................... IV-41

2-16 Summary of Assumptions for CO2 Systems in New MVACs .................................................... IV-43

2-17 Summary of Technical Applicability of Abatement Options by Region (Percent).................. IV-47

2-18 Assumed Regional Market Penetration of Abatement Options into Newly 

Manufactured Equipment, Expressed as a Percentage of Emissions from New 

Equipment ......................................................................................................................................... IV-48

2-19 Market Penetration of Abatement Options, Expressed as a Percentage of Total Sector 

Emissions ........................................................................................................................................... IV-49

2-20 Percentage of (Direct) Reduction Off Baseline Emissions of All Abatement Options by 

Region................................................................................................................................................. IV-50

2-21 Summary of Abatement Option Cost Assumptions (2000$)....................................................... IV-51

2-22 Country/Regional Emissions Reductions in 2010 and Breakeven Costs for 

Refrigeration/Air-Conditioning at 10% Discount Rate, 40% Tax Rate ($/tCO2eq)................... IV-52

2-23 Country/Regional Emissions Reductions in 2020 and Breakeven Costs for 

Refrigeration/Air-Conditioning at 10% Discount Rate, 40% Tax Rate ($/tCO2eq)................... IV-52

2-24 World Breakeven Costs and Emissions Reductions in 2020 for Refrigeration/AirConditioning...................................................................................................................................... IV-53

3-1 General Overview of Solvent Technologies Used Globally........................................................ IV-60

3-2 Total Baseline HFC, PFC, and HFE Emissions Estimates from Solvents (MtCO2eq) .............. IV-62

3-3 Retrofit Techniques for Batch Vapor Cleaning Machine (Less than 13 Square Feet) .............. IV-65

3-4 Technical Applicability and Incremental Maximum Market Penetration of Solvent 

Options (Percent) .............................................................................................................................. IV-67

3-5 Emissions Reductions Off the Total Solvent Baseline (Percent)................................................. IV-68

3-6 Summary of Abatement Option Cost Assumptions .................................................................... IV-68

3-7 Country/Regional Emissions Reductions in 2010 and Breakeven Costs for Solvents at 

10% Discount Rate, 40% Tax Rate ($/tCO2eq)............................................................................... IV-69

3-8 Country/Regional Emissions Reductions in 2020 and Breakeven Costs for Solvents at 

10% Discount Rate, 40% Tax Rate ($/tCO2eq)............................................................................... IV-69

3-9 World Breakeven Costs and Emissions Reductions in 2020 for Solvents ................................. IV-70

4-1 The USEPA’s Vintaging Model Emissions Profile for Foamsȇ End-Uses .................................. IV-79

4-2 Baseline Emissions Estimates for Foams (MtCO2eq) ................................................................... IV-80

4-3 Reduction Efficiency of Foam Options (Percent).......................................................................... IV-90

4-4 Technical Applicability of Foam Options (Percent) ..................................................................... IV-92

4-5 Incremental Maximum Market Penetration Expressed as a Percentage of New 

Emissions for Which the Options Apply....................................................................................... IV-93

4-6 Incremental Maximum Market Penetration Expressed as a Percentage of All Emissions ..... IV-94

4-7 Emissions Reductions Off Total Foams Baseline (Percent) ......................................................... IV-95
XXIV

Number Page

4-8 Summary of Abatement Option Cost Assumptions .................................................................... IV-96

4-9 Country/Regional Emissions Reductions in 2010 and Breakeven Costs for Foams at 10% 

Discount Rate, 40% Tax Rate ($/tCO2eq) ....................................................................................... IV-97

4-10 Country/Regional Emissions Reductions in 2020 and Breakeven Costs for Foams at 10% 

Discount Rate, 40% Tax Rate ($/tCO2eq) ....................................................................................... IV-97

4-11 World Breakeven Costs and Emissions Reductions in 2020 for Foams..................................... IV-98

5-1 Total Baseline HFC Emissions Estimates from MDI Aerosols (MtCO2eq) ............................. IV-106

5-2 Total Baseline HFC Emissions Estimates from Non-MDI Aerosols (MtCO2eq) .................... IV-107

5-3 Technical Applicability and Incremental Maximum Market Penetration of Aerosol 

Options (Percent) ............................................................................................................................ IV-110

5-4 Emissions Reductions Off the Total Applicable Aerosols Baseline (Percent) ........................ IV-110

5-5 Summary of Abatement Option Cost Assumptions .................................................................. IV-111

5-6 Country/Regional Emissions Reductions in 2010 and Breakeven Costs for MDI 

Aerosols at 10% Discount Rate, 40% Tax Rate ($/tCO2eq) ........................................................ IV-112

5-7 Country/Regional Emissions Reductions in 2020 and Breakeven Costs for MDI 

Aerosols at 10% Discount Rate, 40% Tax Rate ($/tCO2eq) ........................................................ IV-112

5-8 Country/Regional Emissions Reductions in 2010 and Breakeven Costs for Non-MDI 

Aerosols at 10% Discount Rate, 40% Tax Rate ($/tCO2eq) ........................................................ IV-113

5-9 Country/Regional Emissions Reductions in 2020 and Breakeven Costs for Non-MDI 

Aerosols at 10% Discount Rate, 40% Tax Rate ($/tCO2eq) ........................................................ IV-113

5-10 World Breakeven Costs and Emissions Reductions in 2020 for Aerosols............................... IV-114

6-1 Total Baseline HFC Emissions from Fire Extinguishing (MtCO2eq) ....................................... IV-123

6-2 Assumed Breakout of Total GWP-Weighted Baseline Fire-Extinguishing Emissions 

(Percent) ........................................................................................................................................... IV-124

6-3 Summary of Technical Applicability of Abatement Options (Percent)................................... IV-130

6-4 Assumed Incremental Market Penetration of Abatement Options into Newly Installed 

Class A or Class B Extinguishing Systems, Expressed as a Percentage of Emissions from 

All New Equipment........................................................................................................................ IV-131

6-5 Market Penetration of Abatement Options into Newly Installed Class A or Class B 

Extinguishing Systems, Expressed as a Percentage of Total Sector Emissions ...................... IV-132

6-6 Percentage of Emissions Reductions Off Total Fire-Extinguishing Baseline.......................... IV-132

6-7 Summary of Abatement Option Cost Assumptions (2000$)..................................................... IV-132

6-8 Country/Regional Emissions Reductions in 2010 and Breakeven Costs for Fire 

Extinguishing at 10% Discount Rate, 40% Tax Rate ($/tCO2eq) ............................................... IV-133

6-9 Country/Regional Emissions Reductions in 2020 and Breakeven Costs for Fire 

Extinguishing at 10% Discount Rate, 40% Tax Rate ($/tCO2eq) ............................................... IV-134

6-10 World Breakeven Costs and Emissions Reductions in 2020 for Fire Extinguishing.............. IV-134

7-1 Total PFC Emissions from Aluminum Manufacturing (MtCO2eq)—No-Action Baseline ... IV-140

7-2 Total PFC Emissions from Aluminum Manufacturing (MtCO2eq)—TechnologyAdoption Baseline........................................................................................................................... IV-140

7-3 Reduction Efficiency Potential for Abatement Option by Cell Type (Percent)...................... IV-143

7-4 Average Baseline Market Penetration of Complete Retrofits by Cell Type and Scenario 

(Percent) ........................................................................................................................................... IV-145
XXV

Number Page

7-5 Emissions Reductions in 2010 and Breakeven Costs ($/tCO2eq) for Aluminum 

Production at 10% Discount Rate, 40% Tax Rate (MtCO2eq)—No-Action Baseline ............. IV-146

7-6 Emissions Reductions in 2020 and Breakeven Costs ($/tCO2eq) for Aluminum 

Production at 10% Discount Rate, 40% Tax Rate (MtCO2eq)—No-Action Baseline ............. IV-147

7-7 Emissions Reductions in 2010 and Breakeven Costs ($/tCO2eq) for Aluminum 

Production at 10% Discount Rate, 40% Tax Rate (MtCO2eq)—Technology-Adoption 

Baseline............................................................................................................................................. IV-147

7-8 Emissions Reductions in 2020 and Breakeven Costs ($/tCO2eq) for Aluminum 

Production at 10% Discount Rate, 40% Tax Rate (MtCO2eq)—Technology-Adoption 

Baseline............................................................................................................................................. IV-148

7-9 Emissions Reduction and Costs in 2020—No-Action Baseline ................................................ IV-148

7-10 Emissions Reduction and Costs in 2020—Technology-Adoption Baseline ............................ IV-149

8-1 Total HFC-23 Emissions from HCFC-22 Production (MtCO2eq)—No-Action Baseline....... IV-155

8-2 Total HFC-23 Emissions from HCFC-22 Production (MtCO2eq)—Technology-Adoption 

Baseline............................................................................................................................................. IV-156

8-3 Baseline Market Penetration of Thermal Oxidation—No-Action Baseline............................. IV-161

8-4 Baseline Market Penetration of Thermal Oxidation—Technology-Adoption Baseline ........ IV-161

8-5 Emissions Reductions in 2010 and Breakeven Costs ($/tCO2eq) for HFC-23 Emissions 

from HCFC-22 Production at 10% Discount Rate, 40% Tax Rate (MtCO2eq)—No-Action 

Baseline............................................................................................................................................. IV-162

8-6 Emissions Reductions in 2020 and Breakeven Costs ($/tCO2eq) for HFC-23 Emissions 

from HCFC-22 Production at 10% Discount Rate, 40% Tax Rate (MtCO2eq)—No-Action 

Baseline............................................................................................................................................. IV-163

8-7 Emissions Reductions in 2010 and Breakeven Costs ($/tCO2eq) for HFC-23 Emissions 

from HCFC-22 Production at 10% Discount Rate, 40% Tax Rate (MtCO2eq)—

Technology-Adoption Baseline..................................................................................................... IV-163

8-8 Emissions Reductions in 2020 and Breakeven Costs ($/tCO2eq) for HFC-23 Emissions 

from HCFC-22 Production at 10% Discount Rate, 40% Tax Rate (MtCO2eq)—

Technology-Adoption Baseline..................................................................................................... IV-164

8-9 World Breakeven Costs and Emissions Reductions in 2020—No-Action Baseline ............... IV-164

8-10 World Breakeven Costs and Emissions Reductions in 2020—Technology-Adoption 

Baseline............................................................................................................................................. IV-164

9-1 Total PFC Emissions from Semiconductor Manufacturing (MtCO2eq)—No-Action 

Baseline............................................................................................................................................. IV-169

9-2 Total PFC Emissions from Semiconductor Manufacturing (MtCO2eq)—TechnologyAdoption Baseline........................................................................................................................... IV-170

9-3 Maximum Market Penetrations for WSC Countries in the No-Action Baseline (Percent) ... IV-174

9-4 Maximum Market Penetrations for Non-WSC Countries in the No-Action Baseline 

(Percent) ........................................................................................................................................... IV-174

9-5 Baseline Market Penetrations for WSC Countries in the Technology-Adoption Baseline 

(Percent) ........................................................................................................................................... IV-175

9-6 Maximum Market Penetrations for WSC Countries in the Technology-Adoption 

Baseline (Percent)............................................................................................................................ IV-175
XXVI

Number Page

9-7 Baseline Market Penetrations for Non-WSC Countries in the Technology-Adoption 

Baseline in 2020 (Percent) .............................................................................................................. IV-175

9-8 Maximum Market Penetrations for Non-WSC Countries in the Technology-Adoption 

Baseline (Percent)............................................................................................................................ IV-176

9-9 Emissions Reductions in 2010 and Breakeven Costs ($/tCO2eq) at 10% Discount Rate, 

40% Tax Rate (MtCO2eq)—No-Action Baseline ......................................................................... IV-180

9-10 Emissions Reductions in 2020 and Breakeven Costs ($/tCO2eq) at 10% Discount Rate, 

40% Tax Rate (MtCO2eq)—No-Action Baseline ......................................................................... IV-180

9-11 Emissions Reductions in 2010 and Breakeven Costs ($/tCO2eq) at 10% Discount Rate, 

40% Tax Rate (MtCO2eq)—Technology-Adoption Baseline..................................................... IV-181

9-12 Emissions Reductions in 2020 and Breakeven Costs ($/tCO2eq) at 10% Discount Rate, 

40% Tax Rate (MtCO2eq)—Technology-Adoption Baseline..................................................... IV-181

9-13 Emissions Reduction and Costs in 2020—No-Action Baseline ................................................ IV-182

9-14 Emissions Reduction and Costs in 2020—Technology-Adoption Baseline ............................ IV-182

10-1 Total SF6 Emissions from Electric Power Systems (MtCO2eq)—No-Action Baseline ........... IV-187

10-2 Total SF6 Emissions from Electric Power Systems (MtCO2eq)—Technology-Adoption 

Baseline............................................................................................................................................. IV-188

10-3 Emissions Reductions in 2010 and Breakeven Costs ($/tCO2eq) for Electric Power 

Systems at a 10% Discount Rate, 40% Tax Rate (MtCO2eq)—No-Action Baseline................ IV-195

10-4 Emissions Reductions in 2020 and Breakeven Costs ($/tCO2eq) for Electric Power 

Systems at 10% Discount Rate, 40% Tax Rate (MtCO2eq)—No-Action Baseline................... IV-196

10-5 Emissions Reductions in 2010 and Breakeven Costs ($/tCO2eq) for Electric Power 

Systems at 10% Discount Rate, 40% Tax Rate (MtCO2eq)—Technology-Adoption 

Baseline............................................................................................................................................. IV-196

10-6 Emissions Reductions in 2020 and Breakeven Costs ($/tCO2eq) for Electric Power 

Systems at 10% Discount Rate, 40% Tax Rate (MtCO2eq)—Technology-Adoption 

Baseline............................................................................................................................................. IV-197

10-7 Emissions Reduction and Costs in 2020—No-Action Baseline ................................................ IV-197

10-8 Emissions Reduction and Costs in 2020—Technology-Adoption Baseline ............................ IV-198

11-1 Total SF6 Emissions from Mg Manufacturing (MtCO2eq)—No-Action Baseline .................. IV-206

11-2 Total SF6 Emissions from Mg Manufacturing (MtCO2eq)—Technology-Adoption 

Baseline............................................................................................................................................. IV-206

11-3 Emissions Reductions in 2010 and Breakeven Costs ($/tCO2eq) for Mg Production at 

10% Discount Rate, 40% Tax Rate (MtCO2eq)—No-Action Baseline ...................................... IV-210

11-4 Emissions Reductions in 2020 and Breakeven Costs ($/tCO2eq) for Mg Production at 

10% Discount Rate, 40% Tax Rate (MtCO2eq)—No-Action Baseline ...................................... IV-211

11-5 Emissions Reductions in 2010 and Breakeven Costs ($/tCO2eq) for Mg Production at 

10% Discount Rate, 40% Tax Rate (MtCO2eq)—Technology-Adoption Baseline.................. IV-211

11-6 Emissions Reductions in 2020 and Breakeven Costs ($/tCO2eq) for Mg Production at 

10% Discount Rate, 40% Tax Rate (MtCO2eq)—Technology-Adoption Baseline.................. IV-212

11-7 Emissions Reduction and Costs in 2020—No-Action Baseline ................................................ IV-212

11-8 Emissions Reduction and Costs in 2020—Technology-Adoption Baseline ............................ IV-212
XXVII

Number Page

Section V 

1-1 DAYCENT N2O and Soil Carbon Estimates for 2000, 2010, and 2020 by Key Region 

(MtCO2eq/yr).........................................................................................................................................V-6

1-2 Cropland N2O and Soil Carbon Mitigation Options Run Through DAYCENT ..........................V-9

1-3 Rice-Only Baseline CH4, N2O, and Soil Carbon Estimates for 2000, 2010, and 2020 by 

Asian Region (Midpoints from DNDC in MtCO2eq/yr; Negative Carbon Numbers 

Indicate Net Sequestration) ...............................................................................................................V-15

1-4 Rice CH4, N2O, and Soil Carbon Mitigation Options Run Through DNDC ..............................V-17

1-5 DNDC Estimates of Net Greenhouse Gas Results for Baseline and Mitigation Scenarios 

for China (Annual Averages in MtCO2eq/yr over 2000–2020) .....................................................V-17

1-6 Changes from Baseline in Greenhouse Gas Emissions, Crop Yields, and Water 

Consumption for China (Annual Averages over 2000–2020; Negative Numbers Indicate 

Decreases Relative to the Baseline)...................................................................................................V-18

1-7 Net Greenhouse Gas Results for Baseline and Mitigation Options for Other Asian 

Countries (Annual Averages in MtCO2eq/yr over 2000–2020).....................................................V-19

1-8 Livestock Enteric Fermentation Greenhouse Gas Mitigation Options........................................V-23

1-9 Livestock Manure Management Greenhouse Gas Mitigation Options.......................................V-25

1-10 Baseline Net GHG Emissions from Croplands from DAYCENT Estimates (MtCO2eq)...........V-33

1-11 Croplands Mitigation Option Detail for Key Regions ...................................................................V-34

1-12 Croplands: Percentage Reductions from Baselines at Different $/tCO2eq Prices ......................V-37

1-13 Baseline Emissions from Rice Cultivation from DNDC Estimates (MtCO2eq)..........................V-41

1-14 Rice Cultivation Mitigation Option Detail for Key Regions .........................................................V-42

1-15 Rice Cultivation: Percentage Reductions from Baseline at Different $/tCO2eq Prices ..............V-43

1-16 Baseline Emissions from Livestock Management from USEPA (2006) (MtCO2eq)...................V-45

1-17 Livestock Mitigation Option Detail for Key Regions.....................................................................V-46

1-18 Livestock Management: Percentage Reductions from Baselines at Different $/tCO2eq 

Prices.....................................................................................................................................................V-49

1-19 Baseline Emissions from All Agriculture Used in This Report (MtCO2eq) ................................V-55

1-20 Total Agriculture: Percentage Reductions from Baseline at Different $/tCO2eq Prices............V-56
XXVIII
Executive Summary 
EXECUTIVE SUMMARY 

ES-ii GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 
EXECUTIVE SUMMARY 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES ES-1

he mitigation of noncarbon dioxide (non-CO2) greenhouse gas emissions can be a relatively 

inexpensive supplement to CO2-only mitigation strategies. The non-CO2 gases include 

methane (CH4), nitrous oxide (N2O), and a number of high global warming potential (highGWP) or fluorinated gases. These gases trap more heat within the atmosphere than CO2 per unit weight. 

Approximately 30 percent of the anthropogenic greenhouse effect since preindustrial times can be 

attributed to these non-CO2 greenhouse gases (Intergovernmental Panel for Climate Change [IPCC], 

2001b); approximately 24 percent of GWP-weighted greenhouse gas emissions in the year 2000 are 

comprised of the non-CO2 greenhouse gases (de la Chesnaye et al., in press; U.S. Environmental 

Protection Agency [USEPA], 2006). 

Given the important role that mitigation of non-CO2 greenhouse gases can play in climate strategies, 

there is a clear need for an improved understanding of the mitigation potential for non-CO2 sources, as 

well as for the incorporation of non-CO2 greenhouse gas mitigation in climate economic analyses. This 

report provides a comprehensive global analysis and resulting data set of marginal abatement curves 

(MACs) that illustrate the abatement potential of non-CO2 greenhouse gases by sector and by region. This 

assessment of mitigation potential is unique because it is comprehensive across all non-CO2 gases, across 

all emitting sectors of the economy, and across all regions of the world. 

The analysis in this report is the latest refinement of the methodology on mitigation of various nonCO2 gases, which has been underway since 1999. A significant contribution to the climate change 

mitigation literature is Stanford University’s Energy Modeling Forum Working Group 21 (EMF-21), 

which focused on mitigation of multiple greenhouse gases and resulted in the publication of a special 

issue of the Energy Journal (see Weyant and de la Chesnaye, in press). The specific non-CO2 mitigation 

papers in the EMF-21 study include energy- and industry-related CH4 and N2O (Delhotal et al., in press); 

agricultural-related CH4 and N2O (DeAngelo et al., in press); and industry-related fluorinated gases 

(Ottinger et al., in press). Much of the original work comes from three previous USEPA studies for the 

United States (2006, 2001, 1999) and a study conducted by the European Commission (EC) (2001) that 

evaluated technologies and costs of CH4 abatement for European Union (EU) members from 1990 to 2010. 

These studies provided estimates of potential CH4 and N2O emissions reductions from major emitting 

sectors and quantified costs and benefits of these reductions. 

Building on the baseline non-CO2 emissions projections from the USEPA’s Global Anthropogenic NonCO2 Greenhouse Gas Emissions: 1990–2020 (2006), this analysis applies mitigation options to the emissions 

baseline in each sector. Across all the emitting greenhouse gas sectors, for each mitigation option, the 

technical abatement potential and cost are calculated. The MACs are determined by the series of 

breakeven price calculations for the suite of available options for each sector and region. Each point along 

the curve indicates the abatement potential given the economically feasible mitigation technologies at a 

given breakeven price. This report makes no explicit assumption about policies that would be required to 

facilitate and generate adoption of mitigation options. Therefore, this report provides estimates of 

technical mitigation potential. 

The result of these efforts is a set of MACs that allow for improved understanding of the mitigation 

potential for non-CO2 sources, as well as inclusion of non-CO2 greenhouse gas mitigation in economic 

modeling. The MAC data sets can be downloaded in spreadsheet format from the USEPA Web site at 

<http://www.epa.gov/nonco2/econ-inv/international.html>. 

Highlights of this analysis include the following: 

T 
EXECUTIVE SUMMARY 

ES-2 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

Mitigation of Non-CO2 Gases Can Play an Important Role in Climate Strategies. Worldwide, the 

potential for “no-regret” non-CO2 greenhouse gas abatement is significant. Figure ES-1 shows the global 

total aggregate MAC for the year 2020. Without a price signal (i.e., at $0/tCO2eq), the global mitigation 

potential is greater than 600 million metric tons of CO2 equivalent (MtCO2eq), or 5 percent of the baseline 

emissions (refer to Section I.3.3 of this report for a more detailed explanation of unrealized mitigation 

potential in the MACs). As the breakeven price rises, the mitigation potential grows. Significant 

mitigation opportunities could be realized in the lower range of breakeven prices. The global mitigation 

potential at a price of $10/tCO2eq is greater than 2,000 MtCO2eq, or 15 percent of the baseline emissions, 

and greater than 2,185 MtCO2eq or 17 percent of the baseline emissions at $20/tCO2eq. In the higher range 

of breakeven prices, the MAC becomes steeper, and less mitigation potential exists for each additional 

increase in price. 

Figure ES-1: Global Total Aggregate MAC for Non-CO2 Greenhouse Gases in 2020 

Globally, the Sectors with the Greatest Potential for Mitigation of Non-CO2 Greenhouse Gases are 

the Energy and Agriculture Sectors. Figure ES-2 shows the global MACs by economic sector in 2020. At a 

breakeven price of $30/tCO2eq, the potential for reduction of non-CO2 greenhouse gases is nearly 1,000 

MtCO2eq in the energy sector, and approximately 600 MtCO2eq in the agriculture sector. While less than 

that of the energy and agriculture sectors, mitigation potential in the waste and industrial processes 

sectors can play an important role, particularly in the absence of a carbon price incentive. 

Methane Mitigation has the Largest Potential across All the Non-CO2 Greenhouse Gases.

Figure ES-3 shows the global MACs by greenhouse gas type for 2020. At or below $0/tCO2eq, the 

potential for CH4 mitigation is approximately 500 MtCO2eq. The potential for reducing CH4 emissions 

grows to nearly 1,800 MtCO2eq as the breakeven price rises from $0 to $30/tCO2eq. While less than that of 

CH4, N2O and high-GWP gases exhibit significant mitigation potential at or below $0/tCO2eq. 

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EXECUTIVE SUMMARY 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES ES-3

Figure ES-2: Global 2020 MACs for Non-CO2 Greenhouse Gases by Major Sector 

Figure ES-3: Global 2020 MACs by Non-CO2 Greenhouse Gas Type 

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Industrial Processes

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Nitrous Oxide

Methane
EXECUTIVE SUMMARY 

ES-4 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

Major Emitting Regions of the World Offer Large Potential Mitigation Opportunities. Figure ES-4 

shows the global MACs by region for 2020. China, the United States, EU, India, and Brazil are the 

countries or regions that emit the most non-CO2 greenhouse gases. As the largest emitters, they also offer 

important mitigation opportunities. These regions show significant mitigation potential in the lower 

range of breakeven prices, with the MACs getting steeper in the higher range of breakeven prices as each 

additional ton of emissions becomes more expensive to reduce. 

Figure ES-4: Global 2020 MACs for Non-CO2 Greenhouse Gases by Major Emitting Regions 

The aggregate MACs by economic sector, greenhouse gas type, and region highlight the importance 

of including non-CO2 greenhouse gases in the analysis of multigas climate strategies. The MACs illustrate 

that a significant portion of this emissions reduction potential can be realized at zero or low carbon 

prices. The mitigation potential in each economic sector is examined in greater detail in this report. 

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United States

China

Rest of the world 
I. Technical Summary 
SECTION I — TECHNICAL SUMMARY 

I-ii GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 
SECTION I — TECHNICAL SUMMARY 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES I-1

I.1 Overview 

he objective of this report is to provide a comprehensive and consistent data set on global 

mitigation of noncarbon dioxide (non-CO2) greenhouse gases to facilitate multigas analysis of 

climate change issues. Mitigating emissions of non-CO2 greenhouse gases can be relatively 

inexpensive compared with mitigating CO2 emissions. Thus, attention has been focused on incorporating 

international non-CO2 greenhouse gas mitigation options into climate economic analyses. This requires a 

large data collection effort and expert analysis of available technologies and opportunities for greenhouse 

gas reductions across diverse regions and sectors. 

This report builds on a study previously conducted by the U.S. Environmental Protection Agency 

(USEPA) for the Energy Modeling Forum, Working Group 21 (EMF-21). The Energy Modeling Forum 

was established by Stanford University to explore energy and environmental issues through the 

collaboration of diverse modeling teams from around the world. The EMF-21 focused specifically on 

multigas strategies to address climate change and resulted in the publication of a special issue of the 

Energy Journal (see Weyant and de la Chesnaye [in press]). The specific non-CO2 mitigation papers in the 

EMF-21 study include energy- and industry-related methane (CH4) and nitrous oxide (N2O) (Delhotal et 

al., in press), agricultural-related CH4and N2O (DeAngelo et al., in press), and industry-related 

fluorinated gases (Ottinger et al., in press). Much of the original work comes from two previous USEPA 

studies for the United States (USEPA, 2001, 1999) and a study conducted by the European Commission 

(EC) (2001) that evaluated technologies and costs of CH4 abatement for EU members from 1990 to 2010. 

Following the basic methodology of the EMF-21 study with some enhancements (as described in 

Section I.3.4 of this report), this report contains detailed analyses by economic sector and region for all 

non-CO2 greenhouse gases over the period from 2000 to 2020. The end result of this report is a set of 

marginal abatement curves (MACs) that allow for improved understanding of the mitigation potential for 

non-CO2 sources, as well as inclusion of non-CO2 greenhouse gas mitigation in economic modeling. The 

MAC data sets can be downloaded in spreadsheet format from the USEPA’s Web site at 

<http://www.epa.gov/nonco2/econ-inv/international.html>. 

I.2 Non-CO2 Greenhouse Gases 

reenhouse gases other than CO2 play an important role in the effort to understand and 

address global climate change. The non-CO2 gases include CH4, N2O, and a number of high 

global warming potential or fluorinated gases. The non-CO2 greenhouse gases are more 

potent than CO2 (per unit weight) at trapping heat within the atmosphere and, once emitted, can remain 

in the atmosphere for either shorter or longer periods of time than CO2. Figure 2-1 shows that these nonCO2 greenhouse gases are responsible for approximately 30 percent of the enhanced, anthropogenic 

greenhouse effect since preindustrial times. 

Table 2-1 shows the global total greenhouse gas emissions for the year 2000, broken down by sector 

and by greenhouse gas type. The non-CO2 gases constitute 24 percent of the global total greenhouse gas 

emissions in 2000. 

T 

G 
SECTION I — TECHNICAL SUMMARY 

I-2 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

Figure 2-1: Contribution of Anthropogenic Emissions of Greenhouse Gases to the Enhanced 

Greenhouse Effect from Preindustrial to Present (measured in watts/meter2) 

Source: IPCC, 2001b. Note that gases regulated under the Montreal Protocol are excluded. 

Table 2-1: Global Greenhouse Gas (GHG) Emissions for 2000 (MtCO2eq) 

Sectors CO2 CH4 N2O 

HighGWP Global 

Total 

Percentage 

of Global 

Total GHGs 

Energy 23,408 1,646 237 25,291 61% 

Agriculture 7,631 3,113 2,616 13,360 32% 

Industry 829 6 155 380 1,370 3% 

Waste 1,255 106 1,361 3% 

Global Total 31,868 6,021 3,114 380 41,382 

Percentage of Global Total GHGs 77% 15% 8% 1% 

Source: Adapted from de la Chesnaye et al., in press; USEPA, 2006. 

I.2.1 Methane (CH4) 

CH4 is about 21 times more powerful at warming the atmosphere than CO2 over a 100-year period.1

In addition, CH4’s chemical lifetime in the atmosphere is approximately 12 years, compared with 

approximately 100 years for CO2. These two factors make CH4 a candidate for mitigating global warming 

in the near term (i.e., within the next 25 years or so) or in the time frame during which atmospheric 

concentrations of CH4 could respond to mitigation actions. 

 

1 Per IPCC (1996) guidelines. The GWP of methane in the IPCC Third Assessment Report (2001a) is 23. 

High-GWP 

Gases

N2O 0.4%

7.1%

CO2

69.6%

CH4

22.9%
SECTION I — TECHNICAL SUMMARY 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES I-3

CH4 is emitted from a variety of manmade sources, including landfills, natural gas and petroleum 

systems, agricultural activities, coal mining, stationary and mobile combustion, wastewater treatment, 

and certain industrial processes. CH4 is also a primary constituent of natural gas and an important energy 

source. As a result, efforts to prevent or capture and use CH4 emissions can provide significant energy, 

economic, and environmental benefits. 

The historical record, based on analysis of air bubbles trapped in glaciers, indicates that CH4 is more 

abundant in the Earth’s atmosphere now than at any time during the past 400,000 years (National 

Research Council [NRC], 2001). Since 1750, global average atmospheric concentrations of CH4 have 

increased 150 percent, from approximately 700 to 1,745 parts per billion by volume (ppbv) 

(Intergovernmental Panel for Climate Change [IPCC], 2001a). Although CH4 concentrations have 

continued to increase, the overall rate of CH4 growth during the past decade has slowed. In the late 1970s, 

the growth rate was approximately 20 ppbv per year. In the 1980s, growth slowed to 9 to 13 ppbv per 

year. From 1990 to 1998, CH4 saw variable growth between 0 and 13 ppbv per year (IPCC, 2001a). A 

recent study by Dlugokencky et al. (2003) shows that atmospheric CH4 was at a steady state of 1,751 ppbv 

between 1999 and 2002. 

Once emitted, CH4 is removed from the atmosphere by a variety of processes, frequently called sinks. 

The balance between CH4 emissions and CH4 removal processes ultimately determines atmospheric CH4

concentrations and determines the length of time CH4 emissions remain in the atmosphere. The dominant 

sink is oxidation within the atmosphere by chemical reaction with hydroxyl radicals (OH). Methane 

reacts with OH to produce alkyd radicals (CH3) and water in the tropospheric layer of the atmosphere. 

Stratospheric oxidation also plays a minor role in removing CH4 from the atmosphere. Similar to 

tropospheric oxidation, in stratospheric oxidation, minor amounts of CH4 are destroyed by reacting with 

OH in the stratosphere. These two reactions account for almost 90 percent of CH4 removal (IPCC, 2001c). 

Other known sinks include microbial uptake of CH4 in soils and the reaction of CH4 with chlorine (Cl) 

atoms in the marine boundary layer. It is estimated that these two sinks contribute 7 percent and less than 

2 percent of total CH4 removal, respectively. 

I.2.2 Nitrous Oxide (N2O) 

N2O is a clear, colorless gas with a slightly sweet odor. Because of its long atmospheric lifetime 

(approximately 120 years) and heat-trapping effects—about 310 times more powerful than CO2 on a permolecule basis—N2O is an important greenhouse gas. 

N2O has both natural and manmade sources and is removed from the atmosphere mainly by 

photolysis (i.e., breakdown by sunlight) in the stratosphere. In the United States, the main manmade 

sources of N2O are agricultural soil management, livestock waste management, mobile and stationary 

fossil fuel combustion, adipic acid production, and nitric acid production. N2O is also produced naturally 

from a variety of biological sources in soil and water. On a global basis, it is estimated that natural 

sources account for over 60 percent of total N2O emissions (IPCC, 2001c). 

Global atmospheric concentrations of N2O have increased from about 270 ppbv in 1750 to 314 ppbv 

in 1998, which equates to a 16 percent increase. In the last 2 decades, atmospheric concentrations of N2O 

continue to increase at a rate of 0.25 percent per year. There has been a significant multiyear variance in 

observed growth of N2O concentrations, but the reasons for these trends are not fully understood yet 

(IPCC, 2001b). 
SECTION I — TECHNICAL SUMMARY 

I-4 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

I.2.3 High-GWP Gases 

There are three major groups or types of high-GWP gases: hydrofluorocarbons (HFCs), 

perfluorocarbons (PFCs), and sulfur hexafluoride (SF6). These compounds are the most potent 

greenhouse gases because of their large heat-trapping capacity and, in the cases of SF6 and the PFCs, their 

extremely long atmospheric lifetimes. Because some of these gases, once emitted, can remain in the 

atmosphere for centuries, their accumulation is essentially irreversible. High-GWP gases are emitted from 

a broad range of industrial sources; most of these gases have few (if any) natural sources. 

I.2.3.1 HFCs 

HFCs are manmade chemicals, many of which have been developed as alternatives to ozonedepleting substances (ODSs) for industrial, commercial, and consumer products. The GWPs of HFCs 

range from 140 (HFC-152a) to 11,700 (HFC-23). The atmospheric lifetime for HFCs varies from just over a 

year (HFC-152a) to 260 years (HFC-23). Most of the commercially used HFCs have atmospheric lifetimes 

of less than 15 years (for example, HFC-134a, which is used in automobile air-conditioning and 

refrigeration, has an atmospheric lifetime of 14 years). 

The HFCs with the largest measured atmospheric abundances are (in order) HFC-23 (CHF3), HFC134a (CF3CH2F), and HFC-152a (CH3CHF2). The only significant emissions of HFCs before 1990 were 

from HFC-23, which is generated as a by-product during the production of HCFC-22. Between 1978 and 

1995, HFC-23 concentrations increased from 3 to 10 parts per trillion (ppt), and these concentrations 

continue to rise. In 1990, HFCs other than HFC-23 were almost undetectable; today, global average 

concentrations of HFC-134a have risen significantly to almost 10 ppt. HFC-134a has an atmospheric 

lifetime of about 14 years and its abundance is expected to continue to rise in line with its increasing use 

as a refrigerant around the world. HFC-152a has increased steadily to about 0.3 ppt in 2000; however, its 

relatively short lifetime (1.4 years) has kept its atmospheric concentration below 1 ppt (IPCC, 2001a). 

I.2.3.2 PFCs 

Primary aluminum production and semiconductor manufacture are the largest known manmade 

sources of tetrafluoromethane (CF4) and hexafluoroethane (C2F6). PFCs are also relatively minor 

substitutes for ODSs. Over a 100-year period, CF4 and C2F6 are, respectively, 6,500 and 9,200 times more 

effective than CO2 at trapping heat in the atmosphere. 

PFCs have extremely stable molecular structures and are largely immune to the chemical processes in 

the lower atmosphere that break down most atmospheric pollutants. Not until the PFCs reach the 

mesosphere, about 60 kilometers above Earth, are they destroyed by very high-energy ultraviolet rays 

from the sun. This removal mechanism is extremely slow; as a result, PFCs accumulate in the atmosphere 

and remain there for several thousand years. The estimated atmospheric lifetimes for CF4 and C2F6

emissions are 50,000 and 10,000 years, respectively. Measurements in 2000 estimated CF4 global 

concentrations in the stratosphere at over 70 ppt. Recent relative rates of concentration increase for these 

two important PFCs are 1.3 percent per year for CF4 and 3.2 percent per year for C2F6 (IPCC, 2001a). 

I.2.3.3 Sulfur Hexaflouride (SF6) 

The GWP of SF6 is 23,900, making it the most potent greenhouse gas evaluated by IPCC. SF6 is a 

colorless, odorless, nontoxic, nonflammable gas with excellent dielectric properties. It is used (1) for 

insulation and current interruption in electric power transmission and distribution equipment; (2) to 

protect molten magnesium from oxidation and potentially violent burning in the magnesium industry; 

(3) to create circuitry patterns and to clean vapor deposition chambers during manufacture of 
SECTION I — TECHNICAL SUMMARY 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES I-5

semiconductors and flat panel displays; and (4) for a variety of smaller uses, including uses as a tracer gas 

and as a filler for sound-insulated windows. 

Like the PFCs, SF6 is very long lived, so all manmade sources contribute directly to its accumulation in 

the atmosphere. Measurements of SF6 show that its global average concentration increased by about 7 

percent per year during the 1980s and 1990s, from less than 1 ppt in 1980 to almost 4 ppt in the late 1990s 

(IPCC, 2001a). 

I.2.4 Use of GWPs in this Report 

The GWP compares the relative ability of each greenhouse gas to trap heat in the atmosphere during 

a certain time frame. Per IPCC (1996) guidelines, CO2 is the reference gas and thus has a GWP of 1. Based 

on a time frame of 100 years, the GWP of CH4 is 21 and the GWP of N2O is 310. Table 2-2 lists all GWPs 

used in this report to convert the non-CO2 emissions into CO2-equivalent units. This report uses GWPs 

from the 1996 IPCC Second Assessment Report (rather than the 2001 Third Assessment Report) because 

these are the values specified by greenhouse gas reporting guidelines under the United Nations 

Framework Convention on Climate Change. 

Table 2-2: Global Warming Potentials 

Gas GWP 

Carbon dioxide (CO2) 1 

Methane (CH4) 21 

Nitrous oxide (N2O) 310 

HFC-23 11,700 

HFC-125 2,800 

HFC-134a 1,300 

HFC-143a 3,800 

HFC-152a 140 

HFC-227ea 2,900 

HFC-236fa 6,300 

HFC-4310mee 1,300 

CF4 6,500 

C2F6 9,200 

C4F10 7,000 

C6F14 7,400 

SF6 23,900 

I.3 Methodology 

his section describes the basic methodology used in this report to analyze potential emissions 

and abatement of non-CO2 greenhouse gases. In this analysis we construct MAC curves for 

each region and sector by estimating the carbon price at which the present value benefits and 

costs for each mitigation option equilibrates. The methodology produces a stepwise curve, where each 

point reflects the average price and reduction potential if a mitigation technology were applied across the 

sector within a given region. This section describes the components of our methodology. First, we 

establish the baseline emissions for each sector in Section I.3.1. Then we describe the methodology used to 

evaluate mitigation options in Section I.3.2, which involves calculating the abatement potential and the 

T 
SECTION I — TECHNICAL SUMMARY 

I-6 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

breakeven price for each option. Lastly, we describe the construction of the MACs in Section I.3.3. Some 

sectors deviate from this methodology depending on specific circumstances, which are briefly mentioned 

here and described in more detail in the sector-specific chapters. 

The results of the analysis are presented as MACs by region and by sector and generally focus on or 

within the 2000 to 2020 time frame. In some cases, sensitivities to the MACs are presented where the 

discount rate, tax rate, and energy prices vary. Emissions abatement in the MACs is shown as both 

absolute emissions reductions and as percentage reductions from the baseline. Non-CO2 emissions 

sources analyzed in this report are coal mining; natural gas production, processing, transmission, and 

distribution; oil production; solid waste management; wastewater; specialized industrial processes; and 

agriculture. 

I.3.1 Baseline Emissions for Non-CO2 Greenhouse Gases 

Current and projected (through 2020) emissions estimates are based primarily on emissions 

projections from the USEPA’s Global Anthropogenic Non-CO2 Greenhouse Gas Emissions: 1990–2020 (USEPA, 

2006). The methods used to estimate and project non-CO2 emissions in USEPA (2006) are briefly 

summarized here. In some cases, particularly for the fluorinated gas emissions and agricultural 

emissions, it was necessary to develop separate baselines from which to assess the mitigation analyses. 

These deviations are also explained in this report. 

For Annex I countries,2 baseline (i.e., reference) projections are based largely on publicly available 

reports produced by the countries themselves. The preferred sources for these reports are the National 

Communications for the United Nations Framework Convention on Climate Change,3 which contain 

current emissions rates and emissions projections through 2020. Estimates from the various countries 

should be comparable because they rely on the same (or similar) IPCC methodologies and countryspecific activity data. 

Estimates of historical and projected emissions for developing countries were based on national and 

international reports. These emissions rates also reflect the most recent results of the USEPA study Global 

Anthropogenic Non-CO2 Greenhouse Gas Emissions: 1990–2020 (USEPA, 2006). The preferred approach to 

estimate emissions from developing countries is to use the latest published information for each country. 

Some developing countries reported emissions estimates from 1990 or later in the latest National 

Communications, in Asia Least-Cost Greenhouse Gas Abatement Strategy (ALGAS) (Asian Development Bank, 

1998), or in a country-specific report. Preference is given to the latest published estimates from the 

National Communications and ALGAS reports, including both historical and projected estimates. 

When the emissions data from these references did not cover the entire historical or projected period 

from 1990 to 2020, or in cases where no emissions data were reported, estimated emissions were obtained 

using the following approaches: 

1. For countries reporting estimates from 1990 to 2010 in 10-year intervals, a linear interpolation 

was used to estimate values in 5-year increments. 

 

2 Annex I countries are countries that are listed in Annex I to the United Nations Framework Convention on Climate 

Change. A complete list of the Annex I countries is available at 

<http://unfccc.int/essential_background/convention/background/items/1346.php>.

3 The National Communications are available at <http://www.unfccc.org>. 
SECTION I — TECHNICAL SUMMARY 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES I-7

2. For countries not reporting emissions through 2000, emissions growth rates were estimated based 

on IPCC Tier 14 estimates for the country for 1990 through 2000. The growth rates were applied to 

reported inventories since 1990 and used to estimate the remaining years through 2000. 

Projections to 2020 are based on growth-rate projections applied to source-specific drivers for 

each country, using the estimate for 2000 as the base year. 

3. When no emissions data were available or when the data were insufficient, the USEPA 

developed emissions estimates, projections, or both, using the default methodology presented in 

the 1996 Revised IPCC Guidelines (IPCC, 1997) and the IPCC Good Practice Guidance (IPCC, 2000). 

Baseline projections represent business-as-usual scenarios, where currently achieved reductions are 

incorporated, but future mitigation actions are only included if either a well-established program or an 

international sector agreement is in place. Thus, projections do not include planned climate change 

source-level mitigation efforts, although they do include voluntary and nonclimate-based policies that 

indirectly reduce greenhouse gases. For consistency, if a country’s reported projections include planned 

climate mitigation efforts, the reductions from those efforts were added back into the emissions 

projections, where identified. If planned climate policy reductions could not be identified, a country’s 

emissions projections were estimated by continuing trends from previous years, as reported in historical 

inventories. 

Source-by-source and country-by-country explanations of how the projections were developed can be 

found in the appendix to USEPA (2006). 

I.3.1.1 Baseline Emissions for Agriculture 

For the agricultural mitigation analysis, separate baseline emissions for croplands and rice cultivation 

were developed and used, even though USEPA (2006) includes estimates for these sources. Process-based 

models—DAYCENT for croplands and DeNitrofication–DeComposition (DNDC) for rice cultivation—

were used for both the baseline emissions estimates and the greenhouse gas implications of mitigation 

options, thus allowing for a clear identification of baseline management conditions and consistent 

estimates of changes to those conditions through mitigation activities. For emissions associated with 

livestock, the mitigation analysis in this report relies on USEPA (2006) baseline estimates. Further details 

about the emissions baselines estimated by the DAYCENT and DNDC models, and their relationship to 

USEPA (2006) estimates, are provided in Section V Agriculture of this report. 

I.3.1.2 Baseline Emissions for Fluorinated Gases 

Baselines for the fluorinated gases are also based on Global Anthropogenic Non-CO2 Greenhouse Gas 

Emissions: 1990–2020 (USEPA, 2006). The 2006 USEPA analysis builds on the 2001 USEPA analysis to 

develop country-by-country and industry-by-industry projections of emissions using projections of 

activity data, emissions factors, or other data related to emissions. For the industrial sources, activity data 

were multiplied by emissions factors to obtain emissions projections. For the substitutes for ODSs, 

estimates of country-specific ODS consumption as reported under the Montreal Protocol were used in 

conjunction with output from the USEPA’s Vintaging Model to project emissions. Activity data and 

activity growth projections were obtained from a variety of sources, including international industry 

trade organizations and databases, U.S. government agencies, and international organizations. For all 

industries, country-specific estimates of activity (or a factor related to activity) were available. 

Information on emissions rates was generally less precise but was often available on a regional, if not 

country-specific, basis. 

 

4 Tier 1 refers to the emissions factor estimation methodology in the IPCC guidelines with the highest level of implied 

accuracy in emissions estimation in a hierarchy of methodology tiers. 
SECTION I — TECHNICAL SUMMARY 

I-8 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

For industrial sources of fluorinated gases, this report presents international baselines and MACs for 

five industrial sources of HFCs, PFCs, and SF6, including the production of aluminum, magnesium, 

semiconductors, and HCFC-22, and the use of electrical equipment in electric power systems. For all five 

of these sources, two sets of baselines and MACs are presented: the technology-adoption baseline, based 

on the assumption that the industries will achieve their announced global emissions reduction goals for 

the year, and the no-action baseline, based on the assumption that the industries’ emissions rates will 

remain constant. Detailed discussions of the methodology used to develop the baselines for each source 

can be found in USEPA (2006). 

In addition to the industrial sectors, this report also includes estimates of fluorinated gases that are 

used as substitutes for ODSs. The USEPA’s Vintaging Model and industry data were used to simulate the 

aggregate impacts of the ODS phaseout on the use and emissions of various fluorocarbons and their 

substitutes in the United States. Emissions estimates for non-U.S. countries incorporate estimates of the 

consumption of ODSs by country, as provided by the United Nations Environment Programme (UNEP) 

(1999). The estimates for the European Union (EU) were provided in aggregate, and each country’s gross 

domestic product (GDP) was used as a proxy to divide the consumption of the individual member nation 

by the EU total. Estimates of country-specific ODS consumption, as reported under the Montreal 

Protocol, were then used in conjunction with Vintaging Model output for each ODS-consuming sector. In 

the absence of country-level data, preliminary estimates of emissions were calculated by assuming that 

the transition from ODSs to HFCs and other substitutes follows the same general substitution patterns 

internationally as observed in the United States. From this preliminary assumption, emissions estimates 

were then tailored to individual countries or regions by applying adjustment factors to U.S. substitution 

scenarios, based on relative differences in economic growth, rates of ODS phaseout, and the distribution 

of ODS use across end-uses in each region or country, as explained in Section IV Industrial Processes in 

this report. 

I.3.2 Mitigation Option Analysis Methodology 

Although non-CO2 emissions from each sector are estimated according to the available data and 

issues important to that sector, the mitigation option analysis throughout this report was conducted using 

a common methodology. This section outlines the basic methodology. The sector-specific chapters 

describe the mitigation estimation methods in greater detail, including any necessary deviations from the 

basic methodology. Mitigation options represented in the MACs of this report are applied to the baselines 

described in Section I.3.1. 

The abatement analysis for all non-CO2 gases for agriculture, coal mines, natural gas systems, oil 

systems, landfills, wastewater treatment, and nitric and adipic acid production are based on and improve 

upon DeAngelo et al. (in press), Delhotal et al. (in press), and Ottinger et al. (in press); two previous 

USEPA studies for the United States (USEPA, 2001, 1999); and a study conducted by the European 

Commission (EC) (2001) that evaluated technologies and costs of CH4 abatement for EU members from 

1990 to 2010. These studies provided estimates of potential CH4 and N2O emissions reductions from 

major emitting sectors and quantified costs and benefits of these reductions. 

The EC study evaluates the abatement potential and cost options at representative facilities or point 

sources of emissions, such as waste digesters, and then extrapolates the results to a country and to the EU 

level. Given the more detailed data available for U.S. estimates, the USEPA’s U.S. analysis also uses 

representative facility estimates but then applies the estimates to a highly disaggregated and detailed set 

of emissions sources for all the major sectors and subsectors. For example, the USEPA analysis of the 

natural gas sector is based on more than 100 emissions sources in that industry, including gas well 
SECTION I — TECHNICAL SUMMARY 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES I-9

equipment, pipeline compressors and equipment, and system upsets. Thus, the EC analysis provides 

more of a sector-average cost for individual abatement options at the country or EU level, while the 

USEPA analysis provides more detail at the sector and subsector levels. 

For this report, average U.S. abatement costs and benefits are estimated for each abatement option to 

build a set of regional options and estimates comparable to that for the EU. Together, this new combined 

set of abatement options is applied to all defined regions in the study, both the United States and the EU, 

as well as to regions where data and detailed analyses are unavailable. The advantage of using the 

“average” approach over the more detailed analyses for the United States and the EU is that the approach 

incorporates the latest emissions estimated and compiled in USEPA (2006) and provides for a consistent 

methodology throughout the analysis for all regions. It should be noted that mitigation estimates from 

this “average” approach are more conservative than those reported in the USEPA and EC reports. 

For the high-GWP abatement analysis, it is assumed that some mitigation technologies are adopted to 

meet industry reduction targets. Therefore, some mitigation options are accounted for in the baseline 

emissions. If an option is assumed to be adopted in the baseline, it is not included when generating the 

MAC. In addition, expert judgment determines market penetration rates of mitigation technologies 

competing for the same set of fluorinated gas emissions. 

The agricultural sector’s emissions abatement analysis improves upon a previous study supported by 

the USEPA (DeAngelo et al., in press) that generated MACs by major world region for cropland N2O, 

livestock enteric CH4, manure CH4, and rice CH4 for the year 2010. The most significant change in this 

report is the use of biophysical, process-based models (i.e., DAYCENT and DNDC) to better capture the 

net greenhouse gas and yield effects and to capture the spatial and temporal variability of those effects 

for the cropland and rice emissions baseline and mitigation scenarios. Use of these process-based models 

is intended to show broad spatial and temporal baseline trends and broad changes when mitigation 

scenarios are introduced, rather than to show definitive absolute emissions numbers for specific locations.

Additional mitigation options are now assessed (e.g., slow-release fertilizers, nitrogen (N)-inhibitors, and 

no-till), and more detailed, less aggregated results are provided for individual crop types under both 

irrigated and rainfed conditions. Improved agriculture MACs are generated for 2000, 2010, and 2020. 

I.3.2.1 Technical Characteristics of Abatement Options 

The non-CO2 abatement options evaluated in this report are compiled from the studies mentioned 

above, as well as from the literature relevant for each sector. For each region, either the entire set of 

sector-specific options or the subset of options determined to be applicable is applied. Options are 

omitted from individual regions on a case-by-case basis, using either expert knowledge of the region or 

technical and physical factors (e.g., appropriate climate conditions). In addition, the rate or extent of 

penetration of an option into the market within different regions may vary based on these conditions. The 

selective omission of options represents a static view of the region’s socioeconomic conditions. Ideally, 

more detailed information on country-specific conditions, technologies, and experiences will be available 

in the future, which will enable more rigorous analyses of abatement option availability over time in each 

region. The average technical lifetime of an option (in years) is also determined using expert knowledge 

of the technology or recent literature, as referenced in each section of this report. 

Table 3-1 summarizes how the abatement potential is calculated for each of the available abatement 

options. The total abatement potential of an option for each region is equal to an option’s technical 

applicability multiplied by its implied adoption rate multiplied by its reduction efficiency. Total baseline 

emissions are summed from each of the emissions sources within each sector and each region. Each 
SECTION I — TECHNICAL SUMMARY 

I-10 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

Table 3-1: Abatement Potential Calculation for Mitigation Options 

Technical applicability 

(%) X 

Implied adoption rate 

(%) X 

Reduction efficiency 

(%) = 

Abatement potential 

(%) 

Percentage of total 

baseline emissions from 

a particular emissions 

source to which a given 

option can be potentially 

applied. 

Percentage of technically 

applicable baseline 

emissions to which a 

given option is applied; 

avoids double counting 

among overlapping 

options and fixes 

penetration rate of options 

relative to each other.a

Percentage of 

technically achievable 

emissions abatement 

for an option after it is 

applied to a given 

emissions stream. 

Percentage of baseline 

emissions that can be 

reduced at the national or 

regional level by a given 

option. Product of technical 

applicability, implied 

adoption rate, and reduction 

efficiency of the option. 

a Implied adoption rate for nonoverlapping options (i.e., applicable to different emissions streams) is assumed to add to 100 percent of 

technically applicable baseline emissions. 

mitigation option reduces baseline emissions by the reduction efficiency percentage of the relevant 

portion of the total baseline emissions, as defined by the technical applicability and implied adoption 

rate. 

Technical applicability accounts for the portion of emissions from a facility or region that a mitigation 

option could feasibly reduce based on its application. For example, if an option applies only to the 

underground portion of emissions from coal mining, then the technical applicability for the option would 

be the percentage of emissions from underground mining relative to total emissions from coal mining. 

The implied adoption rate of an option is a mathematical adjustment for other qualitative factors that 

may influence the effectiveness of a mitigation option. For the energy, waste, and agriculture sectors, it 

was outside the scope of this analysis to account for adoption feasibility, such as social acceptance and 

alternative permutations in the sequencing of adoption. The implied adoption rate of each of the n

overlapping options is equal to 1/n, which avoids cumulative reductions of greater than 100 percent 

across options. Given the lack of region-specific data for determining the relative level of diffusion among 

options that could compete for the same emissions stream, we applied this conservative adjustment. 

When nonoverlapping options are applied, they affect 100 percent of baseline emissions from the relevant 

source. Examples of two nonoverlapping options in the natural gas system are inspection and 

maintenance of compressors and replacement of distribution pipes. These options are applied 

independently to different parts of the sector and do not compete for the same emissions stream. An 

example of overlapping options is the sequencing of cropland mitigation options, where the adoption of 

one option (e.g., conversion to no tillage) affects the effectiveness of subsequent options (e.g., reduced 

fertilizer applications). While this describes the basic application of the implied adoption rate in the 

energy, waste, and agriculture sectors, this factor is informed by expert insight into the potential market 

penetration over time in the industrial processes sector. 

The reduction efficiency of a mitigation option is the percentage reduction achieved with adoption. 

The reduction efficiency is applied to the relevant baseline emissions as defined by technical applicability 

and adoption effectiveness. Most abatement options, when adopted, reduce an emissions stream less than 

100 percent. 

Once the total abatement potential of an option is calculated as described above, the abatement 

potential is multiplied by the baseline emissions for each sector and region to calculate the absolute 
SECTION I — TECHNICAL SUMMARY 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES I-11

amount of emissions reduced by employing the option. The absolute amount of baseline emissions 

reduced by an option in a given year is expressed in million metric tons of CO2 equivalent (MtCO2eq).5

If the options are assumed to be technically feasible in a given region, the options are assumed to be 

implemented immediately, Furthermore, once options are adopted, they are assumed to remain in place 

for the duration of the analysis, and an option’s parameters are not changed over its lifetime. 

I.3.2.2 Economic Characteristics of Abatement Options 

Each abatement option is characterized in terms of its costs and benefits per an abated unit of gas 

(tCO2eq or tons of emitted gas [e.g., tCH4]). 

For each mitigation option, the carbon price (P) at which that option becomes economically viable can 

be calculated (i.e., where the present value of the benefits of the option equals the present value of the 

costs of implementing the option). A present value analysis of each option is used to determine 

breakeven abatement costs in a given region. Breakeven calculations are independent of the year the 

mitigation option is implemented but are contingent on the life expectancy of the option. However, in the 

energy and waste sectors, sensitivities are conducted to examine the implication of time. The net present 

value calculation solves for breakeven price P, by equating the present value of the benefits with the 

present value of the costs of the mitigation option. More specifically, 

¦ ¦ = =

»

1⁄4

o «

¬

a

+

− » = +

1⁄4

o «

¬

a

+

− ⋅ + + T

t

t

T

t

t DR

TR RC CC

DR

TR P ER R TB

1 1 (1 )

(1 )

(1 )

(1 )( )

 (3.1) 

where 

P = the breakeven price of the option ($/tCO2eq); 

ER = the emissions reduction achieved by the technology (MtCO2eq); 

R = the revenue generated from energy production (scaled based on regional energy prices) or 

sales of by-products of abatement (e.g., compost) or change in agricultural commodity prices 

($); 

T = the option lifetime (years); 

DR = the selected discount rate (%); 

CC = the one-time capital cost of the option ($); 

RC = the recurring (O&M) cost of the option (portions of which may be scaled based on regional 

labor costs) ($/year); 

TR = the tax rate (%); and 

TB = the tax break equal to the capital cost divided by the option lifetime, multiplied by the tax rate 

($). 

Assuming that the emissions reduction ER, the recurring costs RC, and the revenue generated R do 

not change on an annual basis, then we can rearrange this equation to solve for the breakeven price P of 

the option for a given year: 

 

5 One MtCO2eq equals 1 teragram of CO2 equivalent (TgCO2eq): 1 metric ton = 1,000 kg = 1.102 short tons = 2,205 lbs.

Net Present Value Benefits Net Present Value Costs
SECTION I — TECHNICAL SUMMARY 

I-12 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

(1 )

(1 )

1 (1 )

1

TR

TR

ER T

CC

ER

R

ER

RC

DR

TR ER

CC P T

t

t

− ⋅ ⋅ + − −

+ −

=

¦=

 (3.2) 

Costs include capital or one-time costs and operation and maintenance (O&M) or recurring costs. 

Additionally, some one-time costs (where data are available) are subdivided into labor and equipment 

components. Recurring costs may also be subdivided into labor costs, fertilizer costs, and other cost 

components. Benefits or revenues from employing an abatement option can include (1) the intrinsic value 

of the recovered gas (e.g., the value of CH4 either as natural gas or as electricity/heat, the value of HFC134a as a refrigerant), (2) nongreenhouse gas benefits of abatement options (e.g., compost or digestate for 

waste diversion options, increases in crop yields), and (3) the value of abating the gas given a greenhouse 

gas price in terms of dollars per tCO2eq ($/tCO2eq) or dollars per metric ton of gas (e.g., $/tCH4, $/tHFC134a). In most cases, there are two price signals for the abatement of CH4: one price based on CH4’s value 

as energy (because natural gas is 95 percent CH4) and one price based on CH4’s value as a greenhouse 

gas. All cost and benefit values are expressed in constant year 2000 U.S. dollars. 

Costs and benefits of abatement options are adjusted based on energy and labor costs in 

corresponding regions. If not otherwise available, the equipment component of fixed costs is not adjusted 

and stays the same for all regions. Most of the agricultural sector options, such as changes in management 

practice, do not have applicable capital costs, with the exception of anaerobic digesters for manure 

management. In general, labor costs comprise the majority of O&M costs. Given this fact, we have used 

labor costs as a proxy to adjust O&M costs across regions, as well as the labor component of the one-time 

cost. Specifically, O&M costs for each region are estimated based on a ratio between the average regional 

labor cost in manufacturing in that region and in the United States for U.S.-based options or the EU for 

EU-based options. Regional labor costs in manufacturing are taken from World Bank data (2000). For the 

agricultural sector, labor costs are calculated labor shares of agricultural production costs from the Global 

Trade Analysis Project (GTAP) and agricultural wage data from the International Food Policy Research 

Institute (IFPRI). 

Breakeven price calculations for this analysis do not include transaction costs, because there are no 

explicit assumptions in this report about policies that would encourage and facilitate adoption of the 

mitigation options. Refer to Section I.5 for a more complete discussion of the limitations of this analysis. 

In regions where there is a lack of detailed revenue data, revenues are scaled based on the ratio 

between average prices of natural gas (when CH4 is abated and sold as natural gas) or of electricity (when 

CH4 is used to generate electricity or heat) in a given region and in the United States or EU. Similarly, 

revenues from non-CH4 benefits of abatement options are scaled based on the ratio between the GDPs 

per capita in a given region and in the United States or EU. In the agricultural sector, changes in revenue 

occur as a change in either crop yield or livestock productivity. Data on changes in crop yield or livestock 

productivity are combined with data on regional producer prices for the relevant agricultural commodity 

to calculate revenue changes. 

This analysis is conducted using a 10 percent discount rate and a 40 percent tax rate. In some sectors, 

sensitivities on alternative discount and tax rates illustrate different social and industry perspectives. 

Sensitivities with a social perspective use lower discount rates and a zero percent tax rate, while 

sensitivities with an industry perspective assume higher discount rates and greater than zero tax rates. 

For quick reference, Table 3-2 lists the basic financial assumptions used throughout this report. In 

addition, because of the high sensitivity to energy prices, the analysis tests the MAC sensitivity to 
SECTION I — TECHNICAL SUMMARY 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES I-13

Table 3-2: Financial Assumptions in Breakeven Price Calculations for Abatement Options 

Variable Assumption 

Discount rate 10% 

Tax rate 40% 

Year dollars 2000$ 

changes in base energy price (from –50 percent to 200 percent) for both electricity and natural gas, where 

this sensitivity test is relevant to the sector. The energy price assumptions are also included in the 

TechTables.xls file in the appendices to the International Analysis of Methane and Nitrous Oxide Abatement 

Opportunities: Report to Energy Modeling Forum, Working Group 21 on the USEPA’s Web site 

<http://www.epa.gov/nonco2/econ-inv/international.html> (USEPA, 2005). 

I.3.3 Marginal Abatement Curves 

MACs are used to show the amount of emissions reduction potential at varying price levels. In 

theory, a MAC illustrates the cost of abating each additional ton of emissions. Figure 3-1 shows an 

illustrative MAC. The x-axis shows the amount of emissions abatement in MtCO2eq, and the y-axis shows 

the breakeven price in $/tCO2eq required to achieve the level of abatement. Therefore, moving along the 

curve, the lowest cost abatement options are adopted first. The curve becomes vertical at the point of 

maximum total abatement potential, which is the sum of abatement across all options in a sector or 

region. 

Figure 3-1: Illustrative Non-CO2 Marginal Abatement Curve 

In Figure 3-1, the commodity/energy market price is aligned to $0/tCO2eq since this price represents 

the point at which no additional price signals exist from GHG credits to motivate emissions reductions; 

all emissions reductions are due to increased energy efficiencies, conservation of production materials, or 

both. As a value is placed on GHG reductions in terms of $/tCO2eq, these values are added to the 

Value of CO2

Equivalent 

($/tCO2eq)

Abated GHG Emissions (MtCO2eq)

Market Price 

$O/tCO2eq

MAC 

Total Abatement Potential Energy/Commodity 

Prices 
SECTION I — TECHNICAL SUMMARY 

I-14 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

commodity/energy market prices and allow for additional emissions reductions to clear the market. The 

points on the MAC that appear at or below the zero cost line ($0/tCO2eq) illustrate this dual price-signal 

market. These “below-the-line” amounts represent mitigation options that are already cost-effective given 

the costs and benefits considered (and are sometimes referred to as “no-regret” options) yet have not 

been implemented because of the existence of nonmonetary barriers. 

The MACs in this report are constructed from bottom-up average breakeven price calculations. The 

average breakeven price is calculated for the estimated abatement potential for each mitigation option 

(see Section I.3.2.2). The options are then ordered in ascending order of breakeven price (cost) and plotted 

against abatement potential. The resulting MAC is a stepwise function, rather than a smooth curve, as 

seen in the illustrative MAC (Figure 3-1), because each point on the curve represents the breakeven price 

point for a discrete mitigation option (or defined bundle of mitigation strategies). Conceptually, marginal 

costs are the incremental costs of an additional unit of abatement. However, the abatement cost curves 

developed here reflect the incremental costs of adopting the next cost-effective mitigation option. We 

estimated the costs and benefits associated with all or nothing adoption of each well-defined mitigation 

practice. We did not estimate the marginal costs of incremental changes within each practice (e.g., the net 

cost associated with an incremental change in paddy rice irrigation). Instead, the MACs developed in this 

report reflect the average net cost of each option for the achieved reduction (ER in Equations 3.1 and 3.2). 

When data were not available to clearly identify marginal abatement roles for mitigation technologies 

because of either (a) the potential for abatement of the same share of baseline emissions, or (b) 

sensitivities to the order of adoption, we employed the implied adoption rate (Table 3-1). 

In the energy and waste sectors, representative facilities facing varied mitigation costs employ 

mitigation technologies based on the lowest average breakeven option price. In calculating the abatement 

potential, options are evaluated according to whether they are complements or substitutes. If a group of 

options are complements (or independent of one another), the implied adoption rates are all equal to one. 

If options are substitutes for each other, the lowest price option is selected for each representative facility; 

in this way, the implied adoption rate for each technology is estimated. 

In the industrial processes sector, mitigation options are applied to one representative facility, in 

order of lowest average breakeven price to highest average breakeven price. Each option is applied to a 

portion of the baseline emissions based on the implied adoption rate (the 1/n factor, as described in 

Section I.3.2.1), which, in the industrial sector, is informed by expert insight into potential adoption rates 

of various mitigation technologies. 

In the agriculture sector, mitigation options are applied to representative farms of each region based 

on the lowest average breakeven price. The implied adoption rate is based purely on the number of 

available migration options (1/n), where each option is applied to an equal portion of the cropland base or 

livestock population and, thus regional baseline emissions, for each region over time. Given the existence 

of nonprice and implementation factors that influence market share and the lack of accurate and detailed 

information regarding these qualitative characteristics, we assume an even distribution of options across 

the baseline for the agriculture sector. This approach allows options to share a portion of market 

penetration, regardless of their cost-effectiveness, rather than allowing only the least-cost option to 

completely dominate the market. Our methodology is more conservative than if we had assumed only 

price factors exist, thus allowing the least-cost option to penetrate the sector by 100 percent. 

The MACs represent the average economic potential of mitigation technologies in that sector, because 

it is assumed that if a mitigation technology is technically feasible in a given region, then it is 

implemented according to the relevant economic conditions. Therefore, the MACs do not represent the 

market potential or the social acceptance of a technology. The models used in the analysis are static (i.e., 
SECTION I — TECHNICAL SUMMARY 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES I-15

they do not represent adoption of mitigation technologies over time). This analysis assumes partial 

equilibrium conditions that do not represent economic feedbacks from the input or output markets. This 

analysis makes no assumptions regarding a policy environment that might encourage the 

implementation of mitigation options. Additional discussion of some key limitations of the methodology 

is provided in Section I.5. 

The end result of this analysis is a tabular data set for the MACs by sector, gas, and region, which are 

presented in Appendix A.6

 Sectoral MACs are aggregated by gas and by region to create global MACs, 

which are presented in Section I.4. 

I.3.4 Methodological Enhancements from Energy Modeling Forum 

Study 

This report builds on a study previously conducted by the USEPA for Stanford’s EMF-21. The EMF21 focused specifically on multigas strategies and the incorporation of non-CO2 greenhouse gas data sets 

into economic models. Although this analysis is built largely on the previous USEPA analysis for the 

EMF-21, we have made several key enhancements. 

In the energy and waste sectors, new sensitivity cases illustrate the effect of technical change over 

time. Introducing technical change by incorporating the rate of change of technical applicability can 

potentially shift the MAC down and to the right on the graph, as abatement potential increases and net 

costs decrease at a given carbon price. 

For industrial sources of fluorinated gases, the emissions baselines have been updated since the EMF21 analysis. The analysis included one set of baseline emissions for industrial sources, while this report 

presents two sets of baselines for aluminum, magnesium, and semiconductor manufacturing. One 

baseline set assumes industry agreements establishing emissions reduction targets will be upheld, while 

the other baseline set assumes that the industry agreement has no effect on the baseline emissions. In 

addition, the MACs for aluminum manufacturing and electrical power systems have been enhanced with 

additional data. 

The emissions baselines in the ODS substitute sector have also been enhanced. The EMF-21 ODS 

substitute baseline was an average between baselines derived by the USEPA and ECOFYS. For this 

report, the USEPA has generated an updated baseline. Assumptions in the ODS substitute sector, such as 

the market penetration potential of various mitigation options, have been updated from the EMF-21 

analysis based on the input of industry experts. 

In the agricultural sector, the previous methodology is improved on for this analysis by using the 

biophysical, process-based models DAYCENT and DNDC. These models capture the net greenhouse gas 

effects of the cropland and rice baseline emissions and mitigation options, and they reflect the 

heterogeneous emissions and yield effects of adopting mitigation practices. In addition, new agricultural 

mitigation options are now assessed, and more detailed results are provided for individual crop types. 

Finally, the agricultural commodity market effects are explored with a global agricultural trade model 

(IMPACT of the IFPRI). 

 

6 Tables are presented that provide the percentage abatement for a series of breakeven prices. The MAC data are 

presented as tables so that exact values can be determined for use in modeling activities. 
SECTION I — TECHNICAL SUMMARY 

I-16 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

I.4 Aggregate Results 

orldwide, 2005 total non-CO2 anthropogenic greenhouse gas baseline emissions are 

estimated to be 10,278 MtCO2eq and are projected to increase by 27 percent to 13,013 

MtCO2eq by 2020. These gases are emitted from four major emitting sectors: the energy, 

waste management, industrial processes, and agricultural industries. China, India, the United States, 

Brazil, and the European Union are the world’s five largest emitters and account for approximately 76 

percent of total non-CO2 emissions. 

This section presents the forecasted baseline emissions and provides a global overview of the results 

from the MAC analysis by sector and for the five largest emitting regions. The data represented in this 

chapter are aggregated and provide a summary of all sources and non-CO2 greenhouse gases. The 

individual chapters are organized by source and present the full details of these analyses. For a complete 

data set of mitigation potential by sector, gas, and region, refer to Appendix A. 

For the purposes of aggregation, the results from the “technology adoption” baseline were used from 

industrial process subsectors with dual baselines. In the agriculture sector, the MAC data from the 

“constant area” scenarios were used, while the baselines from Global Anthropogenic Non-CO2 Greenhouse 

Gas Emissions: 1990–2020 (USEPA, 2006) were used for consistency across the sectors in aggregation. 

I.4.1 Baselines 

I.4.1.1 By Non-CO2 Greenhouse Gas 

Figure 4-1 provides information on the relative share of each greenhouse gas that comprises the 

global non-CO2 greenhouse gas baseline emissions total. CH4 represents the largest share of emissions 

worldwide, accounting for approximately 61 percent of the total non-CO2 emissions in 2005, while N2O 

and high-GWP gases accounted for 34 percent and 5 percent, respectively. 

Figure 4-1: Percentage Share of Global Non-CO2 Emissionsa by Type of Gas in 2005 

Source: USEPA, 2006. 

a CO2 equivalency based on 100-year GWP. 

W 

N2O 34%

High-GWP 5%

CH4 61%

World Total = 10,280 MtCO2eq
SECTION I — TECHNICAL SUMMARY 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES I-17

Figure 4-2 presents the projected baseline emissions by greenhouse gas for 2000, 2010, and 2020. The 

distribution of non-CO2 greenhouse gases is forecasted to remain relatively unchanged through 2020. The 

most significant change is represented by a projected increase in the relative share of high-GWP gases 

with respect to CH4 and N2O, growing from 5 percent to more than 7 percent of global non-CO2

emissions between 2005 and 2020. 

Figure 4-2: Non-CO2 Global Emissions Forecast to 2020 by Greenhouse Gas 

Source: USEPA, 2006. 

I.4.1.2 By Major Emitting Sectors and Countries 

The sources of non-CO2 emissions are categorized into four major emissions sectors: energy, waste, 

industrial processes, and agriculture. Figures 4-3 and 4-4 provide the projected global emissions baseline 

for 2000, 2010, and 2020, by major emissions sector and by major emitting region, respectively. The 

agriculture sector includes soil and manure management, rice cultivation, enteric fermentation, and other 

nonindustrial sources such as biomass burning. Emissions sources categorized in the energy sector include 

coal mining activities, natural gas transmission and distribution, and gas and oil production. The waste 

sector includes municipal solid waste management, as well as human sewage and other types of 

wastewater treatment. The industrial processes sector includes a wide range of activities, such as 

semiconductor manufacturing, primary aluminum production, and electricity transmission and 

distribution. 

Agriculture is the primary source of non-CO2 emissions, accounting for 60 percent of the total 2010 

baseline. Energy is the second largest emissions producer, representing 20 percent of the total baseline. 

The waste sector represents 14 percent of the total baseline, and the industrial processes sector represents 

7 percent. 

Year

MtCO2eq

0

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14,000

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 N2O

 CH4

2000 2010 2020
SECTION I — TECHNICAL SUMMARY 

I-18 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

Figure 4-3: Global Emissions by Major Sector for All Non-CO2 Greenhouse Gases 

Source: USEPA, 2006. Note that this mitigation analysis uses baseline emissions projections for croplands and rice (within agriculture) that 

differ from USEPA (2006) 

Figure 4-4: Projected World Emissions Baselines for Non-CO2 Greenhouse Gases, Including the Top 

Emitting Regions 

Source: USEPA, 2006. 

EU-15 = European Union. 

Year

MtCO2eq

0

2,000

4,000

6,000

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Industrial Processes

Waste

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2000 2010 2020

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0

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Brazil

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Latin America/Caribbean

United States

South & SE Asia

Africa

China

Rest of the world

2000 2010 2020
SECTION I — TECHNICAL SUMMARY 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES I-19

Figure 4-4 shows the projected emissions baselines for the world, as well as the largest emitting 

countries. The largest non-CO2 emitting countries are typically characterized as mature, highly 

industrialized countries or countries with significant agricultural sectors. In 2005, the top five emitting 

countries—China, the United States, EU-15, Brazil, and India—account for 44 percent of the world’s total 

non-CO2 emissions, and their relative contribution to the world baseline is projected to remain the same 

during the next 15 years. 

I.4.2 Global MACs 

The MAC analysis methodology outlined in Section I.3 of this report develops bottom-up projections 

of potential reductions in non-CO2 emissions in terms of the breakeven price ($/tCO2eq). The emissions 

reduction potential is constrained by technology limitations, as well as by regional and geographical 

applicability. In this report, MACs are developed for each major source by sector and country. The 

resulting series of MACs are aggregated up across sectors, gases, and regions. The MACs indicate the 

potential reduction in non-CO2 gas emissions for a given breakeven price. Figure 4-5 presents the results 

from the MAC analysis for 2020 by major economic sector. Figure 4-6 presents aggregate MACs by 

greenhouse gas type for 2020. Figure 4-7 presents the 2020 MACs for the world’s largest non-CO2

greenhouse gas emitting regions. 

Figure 4-5: Global 2020 MACs for Non-CO2 Greenhouse Gases by Major Sector 

-$40

-$30

-$20

-$10

$0

$10

$20

$30

$40

$50

$60

0 250 500 750 1,000 1,250 1,500

Non-CO2 Reduction (MtCO2eq)

$/tCO2eq

Industrial Processes

Waste

Agriculture

Energy
SECTION I — TECHNICAL SUMMARY 

I-20 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

Figure 4-6: Global 2020 MACs by Non-CO2 Greenhouse Gas Type 

Figure 4-7: Global 2020 MACs for Non-CO2 Greenhouse Gases by Major Emitting Regions 

-$40

-$30

-$20

-$10

$0

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$30

$40

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High-GWP

Nitrous Oxide

Methane

-$40

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Brazil

India

EU-15

United States

China

Rest of the world 
SECTION I — TECHNICAL SUMMARY 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES I-21

In the aggregate MACs by gas for the agriculture sector, the net greenhouse gas effects are 

represented in the aggregate MACs by gas for both CH4 and N2O. While mitigating in the livestock and 

rice sectors affects both N2O and CH4 emissions, the dominant effect is on CH4. Thus, for this analysis, the 

net effect on CO2 equivalents is represented in the CH4 global aggregate MAC. Likewise, cropland soil 

mitigation affects both N2O and CH4 emissions, but the net greenhouse gas effect is represented in the 

global aggregate N2O MAC, because N2O is the dominant mitigation effect. 

The 2020 global MACs by major sector (Figure 4-5) illustrate the breakeven mitigation potential for 

each of the economic sectors. The greatest potential for cost-effective mitigation (i.e. employing mitigation 

options that are economically feasible in the absence of a carbon price signal), is in the energy and 

agriculture sectors. In the energy sector, it is estimated that a reduction of approximately 250 MtCO2eq is 

possible at a zero-dollar breakeven price. The MACs also show that at higher emissions prices, such as 

$20 or $30 per tCO2eq, the energy and agriculture sectors show the greatest potential for emissions 

reduction. The industrial processes and waste sectors also show increased mitigation potential at higher 

prices, but to a lesser degree. The more vertical slope of the MAC for the industrial sector shows that an 

increase in the emissions price may not result in any further mitigation beyond a certain point. 

Across all non-CO2 greenhouse gases, methane has the greatest mitigation potential, as shown in the 

2020 MACs by greenhouse gas type (Figure 4-6). In the absence of a carbon price signal, methane 

emissions could be reduced by nearly 500 MtCO2eq. Nitrous oxide and high-GWP gases also exhibit 

significant cost-effective mitigation potential, although to a lesser extent than that of methane. As 

breakeven prices rise, methane potential continues to grow, approaching a reduction potential of 1,800 

MtCO2eq at a breakeven price of $30/tCO2eq. 

The MACs by major emitting regions (Figure 4-7) exhibit China’s large mitigation potential in 2020 at 

higher breakeven prices. At $30/tCO2eq, China could potentially reduce non-CO2 emissions by up to 

nearly 450 MtCO2eq, approximately three times the mitigation potential for the European Union. Both 

China and the United States exhibit the largest potential for mitigation at higher breakeven prices. India 

and Brazil also fall in the largest five emitting regions for non-CO2 greenhouse gases. 

The aggregate MACs by economic sector, greenhouse gas type, and region highlight the potential for 

including non-CO2 greenhouse gases in multigas strategy analysis. The MACs illustrate that a significant 

portion of this mitigation potential can be realized at a zero cost and at low carbon prices. This report 

examines the mitigation potential in each sector in greater detail. Sensitivity analysis on factors such as 

discount rates, the rate of technical change, and the ratio of domestic to foreign inputs can be found in the 

sector-specific chapters of this report. 

I.5 Limitations and Applications of MACs 

hile this global mitigation report has important implications for researchers and modelers, 

it is important to understand not only the limitations of this analysis, but also the potential 

for misapplication of the data in other analyses. 

I.5.1 Limitations and Uncertainties 

The results of this analysis cover the major emitting regions, emissions sources, and abatement 

options; we discuss a few limitations of this analysis briefly below. 

W 
SECTION I — TECHNICAL SUMMARY 

I-22 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

I.5.1.1 Exclusion of Transaction Costs 

Future work in the area of mitigation costs will focus on including transactions costs. Current work 

still in draft by Lawrence Berkeley National Laboratory (LBNL), Transaction Costs of GHG Emissions 

Reduction Projects: Preliminary Results (2003), estimates that transactions costs will add approximately $1 

per ton of carbon to a project. However, the LBNL study is not comprehensive, because it considered only 

two non-CO2 projects. Transaction costs are likely to vary significantly, contingent on the size of the 

project, the applicable mitigation technology, and other factors. Given the lack of comprehensive data, 

this analysis does not include transaction costs. 

I.5.1.2 Static Approach to Abatement Assessment 

This analysis does not account for the technological change in such option characteristics as 

availability, reduction efficiency, applicability, and costs. For example, the same sets of options are 

applied in 2010 and 2020 and an option’s parameters are not changed over its lifetime. This current 

limitation likely underestimates abatement potential because technologies generally improve over time 

and costs fall. The introduction of a dynamic approach to assessing regional abatement potentials 

requires additional assumptions about rates of technological progress and better baseline projections, 

that, once incorporated into this analysis, will yield a better representation of how MACs change over 

space and time. 

I.5.1.3 Limited Use of Regional Data 

The analytic framework used in this study is flexible enough to incorporate regional differences in all 

the characteristics of abatement options. However, a lack of country-specific data led to a reliance on 

expert judgment, as noted in the sector-specific chapters. This expert judgment was obtained from 

source-level technical experts in government and industry with knowledge of project-level technologies, 

costs, and specific regional conditions. Applicability of abatement options, for example, is reliant on 

expert judgment, because the makeup of the current infrastructure in a given country in a given sector is 

uncertain. A much greater use of data originating from local experts and organizations is recommended 

for the follow-up research of CH4 abatement in countries outside the United States and EU. Incorporating 

more regional data could also enhance the range of emissions sources and mitigation options addressed 

in this analysis. 

I.5.1.4 Exclusion of Indirect Emissions Reductions 

This analysis does not account for indirect emissions reductions, which can result from either the 

substitution of electricity from the grid, with electricity produced on-site from recovered CH4, or from the 

substitution of natural gas in pipelines with recovered CH4. Calculation of such indirect reductions 

requires additional assumptions about the carbon intensity of electricity in different regions. In the U.S. 

landfill sector, indirect reductions generally augment emissions reductions by about 15 percent. In the 

agricultural sector, although some mitigation options primarily target a single gas, implementation of the 

mitigation options will have multiple greenhouse gas effects, most of which are reflected in the 

agricultural results. 

I.5.2 Practical Applications of MACs in Economic Models 

MAC data are presented in both percentage reduction and absolute reduction terms relative to the 

baseline emissions. These data can also be downloaded in spreadsheet format from our Web site at 

<http://www.epa.gov/nonco2/econ-inv/international.html>. 
SECTION I — TECHNICAL SUMMARY 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES I-23

The MAC data are an important input into the economic modeling of global climate change. The 

MACs can be applied in a variety of economic models to represent the potential emissions abatement of 

non-CO2 greenhouse gases in each sector at a given carbon price. 

While the results presented in this report can inform economic models, caution should be taken not to 

apply the MAC data directly as offset curves. Offset curves are a supply curve of emissions permits that 

could potentially be available in the market at a given carbon-price environment. However, a price signal 

alone is not likely to bring about all of the mitigation opportunities available along the MACs presented 

in this report. Other nonprice factors, such as social acceptance, tend to inhibit mitigation option 

installation in many sectors. Because of the lack of quantitative data on nonprice factors determining 

market penetration, we have represented the implied adoption rate of mitigation technologies in our 

analysis with a mathematical distribution of technologies across the baseline emissions of a sector. Thus, 

the MACs in our analyses do not represent a supply curve of emissions permits that would be available 

for purchase, but rather the technical mitigation potential at a given carbon price. 

In addition, caution should be taken when applying MACs for sectors that are dependent on energy 

supply, because of the potential sensitivity of the MACs for these sectors to carbon prices. For example, a 

positive carbon-price environment may result in reduction in coal use, which may reduce CH4 emissions. 

This potential reduction in emissions would have occurred because of a decrease in use of the facility, 

rather than the installation of a mitigation option in the facility. 

This analysis focuses only on the mitigation of non-CO2, without considering the impacts of CO2

mitigation. It should be noted that the mitigation potential of non-CO2 greenhouse gas emissions 

generated in the energy sector (e.g., coal mining) is inherently tied to the mitigation potential of CO2

emissions from the same sector. Any modeling of greenhouse gas mitigation in the energy sector should 

consider the coeffects of any change in energy consumption in both non-CO2 and CO2 mitigation 

potential. 

I.6 References 

Asian Development Bank. 1998. Asia Least-Cost Greenhouse Gas Abatement Strategy. Country Studies. 

Manila, Philippines: Asian Development Bank, Global Environment Facility and the United Nations 

Development Programme. 

Committee on the Science of Climate Change, Division on Earth and Life Studies, National Research 

Council (NRC). 2001. “Climate Change Science: An Analysis of Some Key Questions.” Washington, 

DC: National Academy Press. Available at <http://books.nap.edu/openbook/0309075742/html/ 

index.html>. 

de la Chesnaye, F.C., C. Delhotal, B. DeAngelo, D. Ottinger Schaefer, and D. Godwin. In press. “Past, 

Present, and Future of Non-CO2 Gas Mitigation Analysis in Human-Induced Climate Change: An 

Interdisciplinary Assessment.” Cambridge University Press, Cambridge. 

DeAngelo, B.J., F. de la Chesnaye, R.H. Beach, A. Sommer, and B.C. Murray. In press. “Methane and 

Nitrous Oxide Mitigation in Agriculture.” Energy Journal. 

Delhotal, C., F. de la Chesnaye, A. Gardiner, J. Bates, and A. Sankovski. In press. “Estimating Potential 

Reductions of Methane and Nitrous Oxide Emissions from Waste, Energy and Industry.” Energy 

Journal. 

Dlugokencky, E.J., S. Houweling, L. Bruhwiler, K.A. Masarie, P.M. Lang, J.B. Miller, et al. 2003. 

“Atmospheric Methane Levels Off: Temporary Pause Or New Steady State?” Geophysical Research 

Letters 30:10.1029/2003GL018126. 
SECTION I — TECHNICAL SUMMARY 

I-24 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

European Commission (EC). 2001. “Economic Evaluation of Sectoral Emissions Reduction Objectives for 

Climate Change.” Brussels, Belgium: European Commission. Available at <http://europa.eu.int/ 

comm/ environment/enveco/climate_change/sectoral_objectives.htm>. 

Intergovernmental Panel on Climate Change (IPPC). 1996. IPCC Guidelines for National Greenhouse Gas 

Inventories. Three volumes: Vol. 1, Reporting Instructions; Vol. 2, Workbook; Vol. 3, Reference 

Manual. Paris, France: Intergovernmental Panel on Climate Change, United Nations Environmental 

Programme, Organisation for Economic Co-Operation and Development, International Energy 

Agency. 

Intergovernmental Panel on Climate Change (IPPC). 1997. IPCC Guidelines for National Greenhouse Gas 

Inventories. Three volumes: Vol. 1, Reporting Instructions; Vol. 2, Workbook; Vol. 3, Reference 

Manual. Paris, France: Intergovernmental Panel on Climate Change, United Nations Environmental 

Programme, Organisation for Economic Co-Operation and Development, International Energy 

Agency. 

Intergovernmental Panel on Climate Change (IPPC). 2000. “Good Practice Guidance and Uncertainty 

Management in National Greenhouse Gas Inventories.” Kanagawa, Japan: Intergovernmental Panel 

on Climate Change. 

Intergovernmental Panel on Climate Change (IPCC) 2001a. Summary for Policy Makers: A Report of Working 

Group I of the Intergovernmental Panel on Climate Change. The Third Assessment Report of Working 

Group I of the Intergovernmental Panel on Climate Change, Summary for Policy Makers approved in 

Shanghai in January 2001. Available at <www.ipcc.ch>. 

Intergovernmental Panel on Climate Change (IPCC). 2001b. Technical Summary: A Report Accepted by 

Working Group I of the IPCC but not approved in detail. A product resulting from The Third Assessment 

Report of Working Group I of the Intergovernmental Panel on Climate Change, January 2001. 

Available at <www.ipcc.ch>. 

Intergovernmental Panel on Climate Change (IPCC) 2001c. Climate Change 2001: The Scientific Basis. 

Contribution of Working Group I to the Third Assessment Report of the Intergovernmental Panel on 

Climate Change (IPCC), January 2001. Available at <www.ipcc.ch>. 

Ottinger Schaefer, D., D. Godwin, and J. Harnisch. In press. “Estimating Future Emissions and Potential 

Reductions of HFCs, PFCs, and SF6.” Energy Journal. 

Sathaye, A.J., E. Smith, and M. Shelby. 2003. “Transaction Costs of GHG Emissions Reduction Projects: 

Preliminary Results.” Lawrence Berkeley National Laboratory. 

United Nations Environment Programme (UNEP). 1999. The Implications to the Montreal Protocol of the 

Inclusion of HFCs and PFCs in the Kyoto Protocol. UNEP HFC and PFC Task Force of the Technology 

and Economic Assessment Panel (TEAP). 

U.S. Environmental Protection Agency (USEPA). 1999. U.S. Methane Emissions 1990–2020: Inventories, 

Projections, and Opportunities for Reductions. Washington, DC: USEPA, Office of Air and Radiation, 

EPA 430-R-99-013. 

U.S. Environmental Protection Agency (USEPA). 2001. “Addendum Update to U.S. Methane Emissions 

1990–2020: Inventories, Projections, and Opportunities for Reductions.” Washington, DC: USEPA. 

Available at <http://www.epa.gov/ghginfo>. 

U.S. Environmental Protection Agency (USEPA). 2001b. Emissions and Projections of Non-CO2 Greenhouse 

Gases for Developed Countries: 1990–2010. Washington, DC: USEPA. Available at 

<http://www.epa.gov/ghginfo>. 

U.S. Environmental Protection Agency (USEPA). 2002. Emissions and Projections of Non-CO2 Greenhouse 

Gases for Developing Countries: 1990–2020. (Draft). Washington, DC: USEPA. Available via e-mail or 

from the EMF-21 Web site. 

U.S. Environmental Protection Agency (USEPA). 2005. “International Analysis of Methane and Nitrous 

Oxide Abatement Opportunities: Report to Energy Modeling Forum, Working Group 21.” Stanford 

University. Available on the USEPA Web site <http://www.epa.gov/nonco2/econ-inv/ 

international.html>. As obtained on December 21, 2005. 
SECTION I — TECHNICAL SUMMARY 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES I-25

U.S. Environmental Protection Agency (USEPA). 2006. Global Anthropogenic Non-CO2 Greenhouse Gas 

Emissions: 1990–2020. Washington, DC: USEPA. 

Weyant, J. and F. de la Chesnaye (eds.). In press. “Multigas Mitigation and Climate Change.” Energy 

Journal.

World Bank. 2000. “World Development Indicators, Table 2.6 Wages and Productivity.” Washington, DC: 

World Bank. Available at <http://www.worldbank.org>. 
SECTION I — TECHNICAL SUMMARY 

I-26 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 
Section I: Technical Summary Appendixes 

Appendixes for this section are available for download from the USEPA’s Web site at 

http://www.epa.gov/nonco2/econ-inv/international.html. 

II. Energy 
SECTION II — ENERGY • PREFACE 

II-ii GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

Section II presents international emissions baselines and marginal abatement curves (MACs) for energy 

sources. There are three chapters, each addressing an individual source from the coal mining, natural gas, 

and oil sectors. These sources are associated with methane (CH4) emissions. MAC data are presented in 

both percentage reduction and absolute reduction terms relative to the baseline emissions. These data can 

be downloaded in spreadsheet format from the USEPA’s Web site at 

<http://www.epa.gov/nonco2/econ-inv/international.html>. 

Section II—Energy chapters are organized as follows: 

Methane (CH4) 

II.1 Coal Mining Sector 

II.2 Natural Gas Sector 

II.3 Oil Sector 
SECTION II — ENERGY • COAL MINING 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES II-1

II.1 Coal Mining Sector 

orldwide, the coal mining industry liberated more than 377 million metric tons of carbon 

dioxide equivalent (MtCO2eq), which accounted for 3.3 percent of total anthropogenic 

methane (CH4) emissions in 2000. China, the United States, India, and Australia account 

for more than 56 percent of coal mining CH4 emissions (Figure 1-1). Emissions are projected to grow 20 

percent from 2000 to 2020, with China increasing its share of worldwide emissions from 31 percent to 42 

percent. 

Figure 1-1: CH4 Emissions from Coal Mining, by Country: 2000–2020 

Source: U.S. Environmental Protection Agency (USEPA), 2006. 

II.1.1 Introduction 

CH4 is produced during the process of converting organic matter to coal. The CH4 is stored in pockets 

within a coal seam until it is released during coal mining operations. The largest source of emissions 

occurs during mining. Although, some emissions occur during the processing, transport, and storage of 

coal. Many factors affect the quantity of CH4 released, including the gas content of the coal, the 

permeability and porosity of the coal seams, the method of mining used, and the production capacity of 

the mining operation. The depth of a coal seam and the type of coal determine the amount of CH4 present 

(or the gas content) in and around the coal seams. Deep coal seams generally have large amounts of CH4

because of greater overburden pressures. As a result, more than 90 percent of fugitive CH4 emissions 

from the coal sector come from underground coal mining. 

A high concentration of CH4 in underground coal mines is a safety hazard; the CH4 must be extracted 

before mining operations can be undertaken. To maintain low levels of CH4 in the mine, degasification is 

employed prior to mining and ventilation air systems are used during mining operations. Traditionally, 

CH4 extracted from the mine is released or vented into the atmosphere. Abatement options have been 

developed to mitigate these emissions. 

W 

0

100

200

300

400

500

600

2000 2010 2020

Year

MtCO2eq

Australia

India

United States

China

Rest of the world
SECTION II — ENERGY • COAL MINING 

II-2 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

The three coal mining abatement options addressed in this chapter are (1) degasification, where holes 

are drilled and CH4 is captured (not vented) before mining operations begin (or, in the case of gob gas 

wells, during and after mining operations); (2) enhanced degasification, where advanced drilling 

technologies are used and captured low-grade gas is purified; and (3) ventilation air methane (VAM) 

abatement, where low concentrations of CH4 ventilation air exhaust flows are oxidized to generate heat 

for process use and/or electricity generation. 

The following discussion offers a brief explanation of how CH4 is emitted from coal mines, followed 

by a discussion of international baseline emissions for CH4 from coal mining and projections for future 

baseline emissions. Then, we characterize possible abatement technologies, outlining their technical 

specifications, costs and possible benefits, and potential in selected countries. The final section of this 

chapter discusses emissions reductions that occur following the implementation of each abatement 

technology and how these reductions are reflected in the marginal abatement curves (MACs). 

II.1.2 Baseline Emissions Estimates 

Baseline emissions estimates are calculated by developing activity factors and emissions factors per 

unit of activity. The activity factor for coal mining’s level of coal production and the emissions factor are 

expressed in terms of the quantity of CH4 release per ton of coal produced. 

CH4 and coal are created through a combination of biological and geological forces, where plant 

biomass is converted to coal. CH4 is stored in natural wells and is also diffused inside the coal itself. CH4

is contained within the coal seam or strata layer by pressure surrounding the seam. When this pressure 

drops because of natural erosion, faulting, and underground and surface mining, CH4 emissions occur. 

CH4 emissions vary by type of coal mine and type of mining operation. Abandoned mines are also a 

source of CH4 emissions. 

Underground Mines. The quantity of CH4 present in a mine is determined significantly by the coal 

depth. Geologic pressure increases with depth, trapping more CH4. Coal from underground mines tends 

to have a higher carbon content, which is associated with a higher CH4 content. 

Ventilation air systems are used in underground mines to maintain low concentration levels of CH4

during mining operations. CH4 is combustible at concentrations between 5 percent and 15 percent. As a 

safety precaution, countries such as the United States require the use of ventilation systems in mines that 

have any detectable levels of CH4. Ventilation systems maintain a CH4 concentration below 1 percent by 

using large fans to inject fresh air from the surface into the mine, thereby lowering the in-mine CH4

concentration. This ventilation air is extracted from the mine and vented to the atmosphere through 

ventilation shafts or bleeder shafts (see explanatory note 1). The vent air contains very low concentrations 

of CH4 (typically below 1 percent). 

Degasification systems consist of a network of vertical wells drilled from the surface or boreholes 

drilled within the mine and gathering systems to pull the CH4 from the wells to the surface. These wells 

extract large quantities of CH4 from the coal seam before and after mining operations. CH4 extracted by 

degasification systems has higher concentrations (30 percent to 90 percent) than VAM. Concentrations 

vary depending on the type of coal mined and the degasification technique used. 

Surface Mines Surface mining is a technique used to extract coal from shallow depths below the 

Earth’s surface. Because the geologic pressure at shallow depths is much lower, there is insufficient 

pressure to contain high concentrations of CH4, so CH4 content is generally also much lower (see 

explanatory note 2). As the overlying surface is removed and the coal exposed, CH4 is emitted directly 

into the atmosphere. Surface mines contribute only a small fraction of a country’s overall emissions, and 
SECTION II — ENERGY • COAL MINING 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES II-3

surface mining is only applicable in certain geographic regions. For example, in the United States in 2003, 

surface mining accounted for 67 percent of total domestic coal production. In countries such as China, 

there is very little surface mining; coal seams are present only at greater depths. 

Postmining Operations. The primary source of CH4 emissions in coal mining is the underground 

production of coal. However, some emissions occur during processing, storage, and transport of coal. The 

rate of emissions depends on the type of coal and the way it is handled. The highest rate of emissions 

occurs when coal is crushed, sized, and dried for industrial and utility uses. 

Abandoned Mines. Abandoned mines are another source of CH4 emissions. Emissions are released 

through old wells and ventilation shafts. In some cases, the CH4 from these mines has been captured and 

used as a source of natural gas or to generate electricity. Currently, these emissions are not included in 

the baseline estimates. 

In summary, the majority of the CH4 emitted from coal mining comes from gassy underground mines 

through ventilation and degasification systems. Future emissions levels and the potential for CH4

recovery and use will be determined by trends in the management of CH4 gas at such mines. 

II.1.2.1 Activity Data 

Historical Activity Data 

Worldwide coal consumption has increased over time, except in Western Europe, Eastern Europe, 

and the Former Soviet Union (FSU) (excluding the Russian Federation). Coal consumption decreased 30 

percent in Western Europe and 40 percent in Eastern Europe and the FSU from 1990 to 2001. Table 1-1 

reports coal mining activity for selected countries during the same period. 

In the 1990s, the majority of China’s coal mines were operated without modern mining techniques, 

which usually include cutting equipment, hydraulic pumps, power roof supports, and automated 

loading devices. In the past decade, in an effort to update their equipment, countries such as China have 

begun to institute programs to modernize their coal mining operations, allowing them to mine at greater 

depths. However, several countries experienced decreased demand for coal in the late 1990s, and in 

response, these countries cut mining production until their surplus supply could be reduced. China 

dramatically reduced its coal production between 1995 and 2000, and has spent the past 4 years 

expanding its coal exports to reduce its surplus. Policies and market forces such as these counteract the 

effects of modernization in mining operations and subsequently increase CH4 emissions. 

Projected Activity Data 

Estimated CH4 emissions baselines are directly related to coal production projections. Sixty percent of 

the world’s recoverable reserves are located in three regions: the United States (25 percent), FSU (23 

percent), and China (12 percent) (USEIA, 2003). China is projected to have the largest increase in coal 

projections because of rapid economic growth; the country is projected to almost double coal 

consumption by 2025 (USEIA, 2004a). 
SECTION II — ENERGY • COAL MINING 

II-4 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

Table 1-1: Historical Coal Mining Activity Data for Selected Countries (Million Metric Tons) 

Country 1990 1995 2000 2001 2002 2003 

China 1,190.4 1,537.0 1,314.4 1,458.7 1,521.2 1,635.0 

United States 1,029.1 1,033.0 1,073.6 1,127.7 1,094.3 1,069.5 

India 247.6 320.6 370.0 385.4 401.1 403.1 

Australia 225.8 266.5 338.2 362.9 376.8 373.4 

Russian Federation NA 270.9 264.9 273.4 261.8 294.0 

South Africa 193.2 227.3 248.9 250.8 245.8 263.8 

Germany NA 274.2 226.0 227.1 232.6 229.1 

Poland 237.1 221.2 179.5 180.3 178.5 177.8 

Indonesia 11.6 45.4 84.4 102.0 113.9 132.4 

Ukraine NA 94.6 69.1 68.0 65.6 63.5 

Kazakhstan NA 93.1 81.5 93.0 89.2 86.4 

Greece 57.2 63.6 70.4 73.1 77.7 75.3 

Canada 75.3 82.7 76.2 77.6 73.3 68.5 

Czech Republic NA 82.6 71.8 72.9 69.8 70.4 

Turkey 52.3 60.6 69.6 68.3 58.7 53.1 

Rest of the world 1,839.9 370.0 340.9 354.9 355.4 356.4 

World Total 5,347.6 5,096.0 4,930.6 5,225.3 5,259.3 5,406.3 

Source: Energy Information Administration (USEIA), 2004a. 

NA = data unavailable. 

Note: Coal production values include anthracite, bituminous, and lignite coal types. 

II.1.2.2 Emissions Factors and Related Assumptions 

Historical Emissions Factors 

Emissions factors for coal mining vary depending on the type of coal being mined, the depth at which 

the mining face is located, and how much coal is being produced in a given year. In 2000, emissions 

factors for 56 gassy mines in the United States ranged from 57 to 6,000 million cubic feet of CH4 per mine 

annually. Emissions factors for 34 the Russian Federation gassy mines ranged from 17 to 3,200 million 

cubic feet per mine. For China’s 678 state-run mines, emissions factors ranged from 17 to 6,000 million 

cubic feet per mine annually from coal production. While the range of emissions factors for the United 

States and China is similar, China has significantly more mines with higher emissions factors. The 

Intergovernmental Panel on Climate Change (IPCC) estimates average emissions factors by country. 

Table 1-2 reports emissions factors for selected countries. 

Projected Emissions Factors and Related Assumptions 

Improvements made in mining technology throughout the last 20 years have resulted in the ability to 

extract coal from increasingly greater depths. Developing countries’ adoption of advanced mining 

technology has allowed countries such as China and India to reach deeper into their existing coalbed 

reserves. As discussed earlier, the volume of CH4 in the coal seam increases at deeper depths because of 

increasing geological pressure. Thus, CH4 emissions will rise as technology allows large coal-producing 

countries to mine deeper. 
SECTION II — ENERGY • COAL MINING 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES II-5

Table 1-2: IPCC Suggested Underground Emissions Factors for Selected Countries 

Country 

Emissions Factor 

(m3/ton) 

Emissions Factora

(tCO2eq/ton) 

FSU 17.8–22.2 0.25–0.32 

United States 11.0–15.3 0.16–0.22 

Germany 22.4 0.32 

United Kingdom 15.3 0.22 

Poland 6.8–12.0 0.10–0.17 

Czechoslovakia 23.9 0.34 

Australia 15.6 0.22 

Source: IPCC, 1996. Adapted from Reference Manual Table 1-54. 

FSU = Former Soviet Union. 

a Conversion factor of 1 m3 = 0.0143 tCO2eq = 35.31 ft3 × 0.00404 tCO2eq 

II.1.2.3 Emissions Estimates and Related Assumptions 

Historical Emissions Estimates 

Baseline emissions for Annex I countries are built using publicly available reports produced by the 

countries themselves. IPCC’s Revised 1996 IPCC Guidelines for National Greenhouse Gas Inventories

methodology was used to estimate emissions in each country, ensuring comparability across countries 

(IPCC, 1996). The USEPA’s baselines assume a “business-as-usual” scenario that does not include climate 

change mitigation efforts or other national policies that may indirectly reduce the emissions of 

greenhouse gases. 

Table 1-3 reports countries with the largest historical CH4 baseline emissions for the years 1990, 1995, 

and 2000. CH4 emissions declined worldwide between 1990 and 2000 at an average annual rate of about 

10 percent. 

Table 1-3: Historical Baseline Emissions for Coal Mine CH4 for Selected Countries (MtCO2eq) 

Country 1990 1995 2000 

China 126.1 149.1 117.6 

United States 81.9 65.8 56.2 

India 10.9 13.7 15.8 

Australia 15.8 17.5 19.6 

Russian Federation 60.9 36.8 29.0 

Ukraine 55.3 30.1 28.3 

North Korea 25.3 27.2 26.9 

Poland 16.8 15.6 11.9 

South Africa 6.7 6.7 7.1 

United Kingdom 18.3 12.6 7.0 

Germany 25.8 17.6 10.2 

Kazakhstan 24.9 17.2 10.0 

Colombia 1.9 2.0 3.0 

Mexico 1.5 1.8 2.1 

Czech Republic 7.6 5.8 5.0 

Rest of the world 37.2 32.3 27.1 

World Total 516.7 451.5 376.9 

Source: USEPA, 2006. 
SECTION II — ENERGY • COAL MINING 

II-6 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

Projected Emissions Estimates 

Without the introduction of abatement technologies, worldwide CH4 emissions from coal mining are 

projected to increase in the next 20 years. This increase is paralleled by a projected increase in coal 

consumption over the same period. At the same time, coal’s share of overall energy consumption is 

expected to steadily decrease as a result of technology advances in other energy markets, such as natural 

gas, and renewed interest in nuclear energy. 

Technology adoption and organizational restructuring will improve countries’ abilities to produce 

larger amounts of coal each year. Table 1-4 reports predicted CH4 baseline emissions for the largest coalproducing countries in the world, assuming the absence of CH4 abatement technologies. 

Table 1-4: Projected Baseline Emissions for Coal Mine CH4 for Selected Countries (MtCO2eq) 

Country 2005 2010 2015 2020 

China 135.7 153.8 171.8 189.9 

United States 55.3 51.1 46.4 46.4 

India 19.5 23.1 28.4 33.6 

Australia 21.8 26.4 28.2 29.7 

Russian Federation 26.3 27.5 26.9 26.3 

Ukraine 26.3 24.5 23.8 23.2 

North Korea 25.6 24.3 23.1 21.9 

Poland 11.3 10.8 10.3 9.8 

South Africa 7.4 7.2 7.1 7.4 

United Kingdom 6.7 6.6 6.4 6.2 

Germany 8.4 7.7 7.1 5.9 

Kazakhstan 6.7 6.4 6.1 5.8 

Colombia 3.4 4.0 4.7 5.5 

Mexico 2.5 2.8 3.3 3.7 

Czech Republic 4.8 3.9 3.1 3.0 

Rest of the world 26.5 27.5 28.9 31.1 

World Total 388.1 407.6 425.6 449.5 

Source: USEPA, 2006. 

II.1.3 Cost of CH4 Emissions Reductions from Coal Mining 

The following is a discussion of the abatement technologies and their costs and benefits. 

II.1.3.1 Abatement Option Opportunities 

Three abatement opportunities currently available to the coal mining sector are 

• degasification, 

• enhanced degasification, and 

• oxidation of VAM. 
SECTION II — ENERGY • COAL MINING 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES II-7

Engineering costs for each abatement option are based on representative mine characteristics, such as 

annual mine production, gassiness of the coal deposits, and CH4 concentration in ventilation flows. 

Table 1-5 provides a summary of the one-time investment costs, annual operation and maintenance 

(O&M) costs, and benefits from using the captured CH4 as an energy source for each of the three coal 

mining abatement options included in the analysis. 

Table 1-5: Summary of Average Abatement Costs and Benefits for U.S. Coal Mines (in 2000$)a

Average Costs/Benefits (Millions in 2000$) 

Costs Degasification 

Enhanced 

Degasificationb VAMc

One-Time Costs 

Compressor capital $1.00 $0.39 N/A 

Gathering line capital $0.90 $0.20 N/A 

Processing capital $0.04 $2.56 N/A 

Ventilation capital N/A N/A $18.64 

Miscellaneous capital $0.38 $0.14 N/A 

Annual Costs 

Drilling capital $0.50 $0.36 N/A 

Drilling materials $0.94 $0.31 N/A 

Compressors energy (kWh) $0.33 $0.13 N/A 

Gathering lines labor $0.25 $0.96 N/A 

Processing materials $0.13 $0.18 N/A 

Ventilation operating costs N/A N/A $0.91 

Miscellaneous labor $0.28 $0.12 N/A 

Annual After-Tax Benefits 

CH4 sold or purchases offset $0.97 $0.34 $2.78 

Depreciation Tax Benefits $0.02 $0.24 $0.14 

Source: Gallaher and Delhotal, 2005. 

N/A = Not applicable. 

a Based on a population of 57 U.S. coal mines, accounting for 75 percent of the total liberated CH4 from U.S. coal production. 

b Incremental costs and benefits in addition to degasification (Option 1). 

c Underlying VAM costs are from Delhotal et al. (2005). 

Degasification and Pipeline Injection 

High-quality CH4 is recovered from coal seams by drilling vertical wells up to 10 years in advance of 

a mining operation or drilling horizontal boreholes up to 1 year before mining. Most mine operators 

exercise just-in-time management of gate road development; subsequently, horizontal cross-panel 

boreholes are installed and drain gas for 6 months or less. Long horizontal boreholes are used by only a 

few operators in the United States and Australia. 

In some cases, high-quality CH4 also can be obtained from gob wells. Gob gas CH4 concentrations can 

range from 50 percent to over 90 percent (USEPA, 1999). The gas recovered is injected into a natural gas 

pipeline requiring virtually no purification in the initial stages of production, but necessitating treatment 

over time to upgrade the gas to pipeline quality. Gob gas sales from a given location typically decline 

over time because of declining levels of concentration. In the United States, of the CH4 recovered from 

degasification (or gas drainage as it is often called) 57 percent can be directly used for pipeline injection 

(USEPA, 1999). 
SECTION II — ENERGY • COAL MINING 

II-8 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

Cost Analysis 

• Capital Costs. Capital costs include the one-time (upfront) costs of purchasing compressors, 

gathering lines, dehydrators, and other miscellaneous capital such as safety equipment and 

licenses. Table B-6 in Appendix B for this chapter offers a detailed description of the factors that 

determine the required number of each capital component by mine.

• Annual Costs. These costs include materials and labor for drilling, moving gathering lines, and 

maintaining the dehydrators. Drilling capital is also considered an annual cost because drilling is 

conducted annually. Annual costs generally increase or decrease proportionally to the volume of 

CH4 liberated at the individual mine. Table B-6 offers a detailed description of the factors that 

determine these costs. 

• Cost Savings. Cost savings result from the capture and reuse of natural gas. For basic 

degasification, it is assumed that 57 percent of gas capture is suitable for injection into the natural 

gas pipelines and hence can be sold directly into the system (USEPA, 1999). 

Enhanced Degasification and Pipeline Injection 

In enhanced degasification, CH4 is recovered in the same way as in degasification, using vertical 

wells, horizontal boreholes, and gob wells. In addition, the mine invests in enrichment technologies such 

as nitrogen removal units (NRUs) and dehydrators, used primarily to enhance medium-quality gob well 

gas by removing impurities, allowing for larger quantities of CH4 to be captured and used. This option 

also assumes tighter well spacing to increase recovery. The enrichment process and tighter spacing 

improve recovery efficiency 20 percent more than the first option discussed above (USEPA, 1999). All 

costs and benefits presented in Table 1-5 for enhanced degasification are incremental in that they 

represent additional abatement costs and CH4 sales above and beyond the basic degasification. 

Cost Analysis 

• Capital Costs. Enhanced degasification requires the same capital equipment as the degasification 

option. In addition, the enhanced option requires an NRU with an estimated average cost of 

$200,000 per unit. 

• Annual Costs. Similar to degasification, enhanced degasification’s annual costs include materials 

and labor for drilling, moving gathering lines, and maintaining the dehydrators. However, 

annual drilling costs are higher for enhanced degasification because the wells are drilled at closer 

intervals to one another. Costs vary proportionally to the amount of gas liberated. 

• Cost Savings. It is assumed that 77 percent of the CH4 captured as part of enhanced 

degasification can be injected into the natural gas pipeline system. There is a 21 percent increase 

over the basic degasification mitigation option (incremental benefits) because gas processing 

equipment facilitates nitrogen removal. 

Oxidation of Ventilation Air Methane 

Oxidation technologies (both thermal and catalytic) have the potential to use CH4 emitted from coal 

mine ventilation air. It is not economically feasible to sell this gas to a pipeline because of its extremely 

low CH4 concentration levels (typically below 1 percent). However, VAM can be oxidized to generate 

CO2 and heat, which in turn may be used directly to heat water or to generate electricity. If oxidizer 

technology were applied to all mine ventilation air with concentrations greater than 0.15 percent CH4, 

approximately 97 percent of the CH4 from the ventilation air could be mitigated. 
SECTION II — ENERGY • COAL MINING 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES II-9

Cost Analysis 

• Capital Costs. Capital costs for VAM oxidation are a function of the level of CH4 concentration in 

the ventilation air and the ventilation air flow rate. 

• Annual Costs. Annual costs consist primarily of the labor and electricity costs associated with 

running the oxidizer. Both of these are proportional to coal production. 

• Cost Savings. Heat generated by oxidation systems can be used to heat water (e.g., for steam or 

district heating applications) or to generate electricity. 

II.1.4 Results 

This section presents the Energy Modeling Forum (EMF) Working Group 21 study’s MAC analysis 

results in tabular format. 

II.1.4.1 Data Tables and Graphs 

Table 1-6 presents the average breakeven price and the reduction in absolute and percentage terms 

for the mitigation options discussed in Section II.1.3.1. 

Table 1-6: Summary of Coal Mining Abatement Options Included in the Analysis

Technology 

Breakeven 

Cost 

($/tCO2eq) 

Emissions 

Reduction (% 

from baseline) 

Emissions 

Reduction in 

2010 (MtCO2eq) 

Emissions 

Reduction in 

2020 (MtCO2eq) 

Assuming a 10% discount rate and a 40% tax rate 

Degasification and pipeline injection –$11.66 28% 0.55 0.55 

Enhanced degasification, gas 

enrichment, and pipeline injection 

$2.40 10% 0.19 0.19 

Catalytic oxidationa (United States) $14.36 24% 0.77 0.94 

Flaring $2.47 1% 0.03 0.03 

Degasification and power production—A –$2.09 5% 0.04 0.03 

Degasification and power production—B $5.68 9% 0.06 0.06 

Degasification and power production—C $19.80 28% 0.70 0.83 

Catalytic oxidation (EU-15) $11.34 18% 0.13 0.11 

Source: USEPA, 2003. Adapted from Coal Sector technology tables in Appendix B of EMF report. 

EU-15 = European Union. 

Note: Some technologies are not present in all countries. See source for the individual technology’s presence in various countries. a Catalytic oxidation is considered a VAM technology. 

The EMF regional baselines and MAC results of the EMF-21 study are presented in Tables 1-7 and 1-8 

for 2010 and 2020 using the base energy price, a 10 percent discount rate, and a 40 percent tax rate. These 

MACs represent percentage reductions in baseline emissions for individual regions/countries at selected 

breakeven prices. Figure 1-2 provides MACs for the five EMF countries/regions with the largest estimated 

emissions from coal mining in 2020. 

The MACs presented in this section represent static abatement curves using breakeven prices built on 

the assumption of fixed mitigation cost and aggregate countrywide natural gas statistics. Appendix B 

presents more recent efforts to develop an alternative framework for conducting MAC analysis that 

addresses the limitations of the EMF-21 MAC analysis. 
SECTION II — ENERGY • COAL MINING 

II-10 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

Table 1-7: Baseline Emissions by EMF Regional Grouping: 2000–2020 (MtCO2eq) 

Country/Region 2000 2010 2020 

Africa 9.3 8.2 8.7 

Annex I 181.9 173.5 165.8 

Australia/New Zealand 20.0 26.8 30.3 

Brazil 1.3 1.1 1.0 

China 117.6 153.8 189.9 

Eastern Europe 24.3 23.4 24.1 

EU-15 22.5 19.6 17.0 

India 15.8 23.1 33.6 

Japan 0.8 0.7 0.7 

Mexico 2.1 2.8 3.7 

Non-OECD Annex I 61.7 56.8 54.7 

OECD 123.5 120.2 115.3 

Russian Federation 29.0 27.5 26.3 

South & SE Asia 31.7 29.8 28.4 

United States 56.2 51.1 46.4 

World Total 376.9 407.6 449.5 

Source: USEPA, 2006. 

EU-15 = European Union; OECD = Organisation for Economic Co-operation and Development. 

Note: World Total does not equal the sum of the countries listed in this table because the regional groupings are a subset of the full EMF 

regional grouping list. See Appendix A of this report for the full EMF list of countries by region. 

Table 1-8: Coal Mining MACs for Countries Included in the Analysis 

2010 2020 

Country/Region $0 $15 $30 $45 $60 $0 $15 $30 $45 $60 

Africa 38.50% 85.53% 85.53% 85.53% 85.53% 38.50% 85.53% 85.53% 85.53% 85.53% 

Annex I 34.81% 78.05% 78.05% 78.05% 78.05% 36.33% 81.45% 81.45% 81.45% 81.45%

Australia/New Zealand 27.91% 83.05% 83.05% 83.05% 83.05% 27.91% 83.05% 83.05% 83.05% 83.05% 

Brazil 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 

China 0.00% 84.45% 84.45% 84.45% 84.45% 0.00% 84.45% 84.45% 84.45% 84.45% 

Eastern Europe 34.16% 73.23% 73.23% 73.23% 73.23% 34.16% 73.23% 73.23% 73.23% 73.23% 

EU-15 0.00% 41.11% 41.11% 41.11% 41.11% 0.00% 41.11% 41.11% 41.11% 41.11% 

India 0.00% 84.18% 84.18% 84.18% 84.18% 0.00% 84.18% 84.18% 84.18% 84.18% 

Japan 98.00% 98.00% 98.00% 98.00% 98.00% 98.00% 98.00% 98.00% 98.00% 98.00% 

Mexico 28.50% 85.53% 85.53% 85.53% 85.53% 28.50% 85.53% 85.53% 85.53% 85.53% 

Non-OECD Annex I 32.10% 84.80% 84.80% 84.80% 84.80% 39.21% 103.58% 103.58% 103.58% 103.58%

OECD 35.40% 75.22% 75.22% 75.22% 75.22% 34.95% 74.26% 74.26% 74.26% 74.26%

Russian Federation 27.65% 84.29% 84.29% 84.29% 84.29% 27.65% 84.29% 84.29% 84.29% 84.29% 

South & SE Asia 28.15% 84.09% 84.09% 84.09% 84.09% 28.15% 84.09% 84.09% 84.09% 84.09% 

United States 49.22% 85.97% 85.97% 85.97% 85.97% 49.22% 85.97% 85.97% 85.97% 85.97% 

World Total 16.66% 79.84% 79.84% 79.84% 79.84% 14.51% 79.81% 79.81% 79.81% 79.81% 

Source: USEPA, 2003. 

EU-15 = European Union; OECD = Organisation for Economic Co-operation and Development. 
SECTION II — ENERGY • COAL MINING 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES II-11

Figure 1-2: EMF MACs for Top Five Emitting Countries/Regions from Coal: 2020 

Source: USEPA, 2003. 

Note: Regional MACs were constructed using percentage reductions from USEPA (2003), with baselines from USEPA (2005). 

II.1.4.2 Uncertainties and Limitations 

Several key limitations in current data availability constrain the accuracy of this analysis. Successfully 

addressing these issues would improve development of the MACs and predictions of their behavior as a 

function of time. Some of these limitations include the following. 

• Accurate Distribution of Mine Type for Each Country. Extrapolating from available information 

about individual mines to project fugitive emissions at a national level implies that the available 

data are representative of the country’s coal production not already included in the existing 

database. A more accurate distribution of representative mines would improve the accuracy of 

the cost estimates and the shape of each MAC. These data would include mines of all sizes, 

emissions factors, and production levels. This lack of information becomes increasingly 

problematic when evaluating a country such as China, where the majority of mines are small, 

private mines that are not represented in currently available data sources. 

• Country-Specific Tax and Discount Rates. In this analysis, a single tax rate is applied to mines in 

all countries to calculate the annual benefits of each technology. In reality, however, tax rates 

vary across countries, and in the case of state-run mines in China, taxes may not even be 

applicable. Similarly, the discount rate may vary by country. Improving the level of countryspecific detail will help analysts more accurately quantify benefits and breakeven prices. 

• Improved Information on Public Infrastructure. A more detailed understanding of each 

country’s natural gas infrastructure would improve the estimates of costs associated with 

transporting CH4 from a coal mine to the pipeline. Countries with little infrastructure will have a 

much higher transportation cost associated with degasification and enhanced degasification 

technologies. 

-$10

$0

$10

$20

$30

$40

$50

0 50 100 150 200 250

Absolute Reduction (MtCO2eq)

$/tCO2eq

United States

Russian Federation

South & SE Asia

China

Australia/New Zealand
SECTION II — ENERGY • COAL MINING 

II-12 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

• Concentrations for VAM in International Mines. The effectiveness and applicability of VAM 

technology depends on VAM concentration and mine-specific coal production rates. Improved 

data on the VAM concentration levels for individual mines would enhance the accuracy of cost 

estimates. This information would also help to more accurately identify the minimum threshold 

concentration levels that make VAM oxidation an economically viable option. 

II.1.5 Summary 

The methodology and data discussed in this section describe the MAC analysis conducted for the 

coal mining sector by the EMF-21 study. MACs for 2010 and 2020 were estimated based on aggregated 

industry data from each country or region. The MACs represent static estimates of potential CH4

mitigation from coal mines based on available information regarding infrastructure and country-reported 

emissions estimates provided through the United Nation’s Framework Convention on Climate Change 

emissions inventory reports. 

II.1.6 References 

Delhotal, C., F. de la Chesnaye, A. Gardiner, J. Bates, and A. Sankovski. In press. “Estimating Potential 

Reductions of Methane and Nitrous Oxide Emissions from Waste, Energy and Industry.” Energy 

Journal. 

Gallaher, M., and K. C. Delhotal. 2005. “Modeling the Impact of Technical Change on Emissions 

Abatement Investments in Developing Countries.” Journal of Technology Transfer 30 1/2, 211-255. 

Intergovernmental Panel on Climate Change (IPCC). 1996. Revised 1996 IPCC Guidelines for National 

Greenhouse Gas Inventories: Reference Manual (Volume 3). Available at <http://www.ipcc-nggip. 

iges.or.jp/public/gl/invs6.htm>. As obtained on April 26, 2004. 

U.S. Energy Information Administration (USEIA). 2003. International Energy Annual 2001. Table 2.5. 

DOE/EIA-0219 (2001) Washington, DC: USEIA. 

U.S. Energy Information Administration (USEIA). 2004a. International Energy Annual 2002. Table 7.5. 

Washington, DC: USEIA. 

U.S. Energy Information Administration (USEIA). 2004b. System for the Analysis of Global Energy Markets.

Washington, DC: USEIA. 

U.S. Environmental Protection Agency (USEPA). 1999. U.S. Methane Emissions 1990–2020: Inventories, 

Projections, and Opportunities for Reductions. EPA 430-R-99-013. Washington, DC: USEPA Office of Air 

and Radiation. 

U.S. Environmental Protection Agency (USEPA). 2003. International Analysis of Methane and Nitrous 

Oxide Abatement Opportunities: Report to Energy Modeling Forum, Working Group 21. 

Appendices. Washington, DC: USEPA. Available at <http://www.epa.gov/methane/ 

intlanalyses.html>. As obtained on September 27, 2004. 

U.S. Environmental Protection Agency (USEPA). 2006. Global Anthropogenic Non-CO2 Greenhouse Gas 

Emissions: 1990–2020. Washington, DC: USEPA. 
SECTION II — ENERGY • COAL MINING 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES II-13

Explanatory Notes 

1. Bleeder shafts are currently used in only a limited number of countries, including the United States 

and the Russian Federation. 

2. There are exceptions. In Kazakhstan, for example, the surface mines in Ekibastuz are very gassy and 

prone to outbursts; this is the rare exception, though. 
SECTION II — ENERGY • COAL MINING 

II-14 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 
SECTION II — ENERGY • NATURAL GAS 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES II-15

II.2 Natural Gas Sector 

atural gas systems are a leading source of anthropogenic CH4 emissions, accounting for 

more than 970 MtCO2eq (USEPA, 2006). The USEPA estimates that natural gas systems 

account for 8 percent of total global CH4 emissions. The Russian Federation, the United 

States, Africa, and Mexico account for more than 43 percent of the world’s CH4 emissions in the natural 

gas sector (USEPA, 2006) (Figure 2-1). 

Figure 2-1: CH4 from Natural Gas Systems by Country: 2000–2020 

Source: USEPA, 2006. 

Emissions are projected to increase 54 percent from 2005 to 2020, with Brazil and China having the 

largest growth of 737 percent and 611 percent, respectively (USEPA, 2006). The two regions projected to 

experience the largest growth in production are the Middle East and the developing countries of Latin 

America. 

II.2.1 Introduction 

Natural gas systems include the production, processing, transportation and storage, and distribution 

of natural gas. Table 2-1 identifies facilities and equipment associated with different segments of the 

natural gas system. 

During production, gas exit swells under pressure greater than 1,000 pounds per square inch (psi). 

The gas is routed through dehydrators, where water and other liquids are removed, and then to smalldiameter gathering lines for transport to either processing plants or injection directly into transmission or 

distribution pipelines. Processing plants further purify the gas by removing natural gas liquids, sulfur 

compounds, particulates, and CO2. Impurities in the gas are extracted through a cooling process that 

forces the impurities to condense into a liquid, which is then vaporized in a reboiler and vented into the 

atmosphere. 

N 

0

250

500

750

1,000

1,250

1,500

1,750

2,000

2000 2010 2020

Year

MtCO2eq 

Mexico

Africa

United States

Russian Federation

Rest of the world
SECTION II — ENERGY • NATURAL GAS 

II-16 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

Table 2-1: Natural Gas Industry Characterization 

Segment Facility Equipment at the Facility 

Production Wells, central gathering facilities Wellheads, separators, pneumatic devices, 

chemical injection pumps, dehydrators, 

compressors, heaters, meters, pipelines 

Processing Gas plants Vessels, dehydrators, compressors, acid gas 

removal (AGR) units, heaters, pneumatic devices 

Transmission and 

storage 

Transmission pipeline networks, compressor 

stations, meter and pressure-regulating stations, 

underground injection/withdrawal facilities, 

liquefied natural gas (LNG) facilities 

Vessels, compressors, pipelines, meters/pressure 

regulators, pneumatic devices, dehydrators, 

heaters 

Distribution Main and service pipeline networks, meter and 

pressure-regulating stations 

Pipelines, meters, pressure regulators, pneumatic 

devices, customer meters 

Source: USEPA, 1996. 

Processed gas, which is 95 percent CH4, is then injected into large-diameter transmission pipelines, 

where it is compressed and transported to storage and distribution facilities. Storage stations are either 

above- or belowground facilities and include compressor stations. Distribution companies reduce highpressure gas (averaging 300 psi to 600 psi) to pounds or even ounces per square inch for delivery to 

homes, businesses, and industries. 

CH4 emissions occur from normal operations in each of the four segments of the natural gas industry. 

Equipment/pipeline leaks and venting activities are the primary sources of CH4 emissions in the natural 

gas sector (USEPA, 1996). As the gas moves through system components under extreme pressure, CH4

can escape to the atmosphere through worn valves, flanges, pump seals, compressor seals, and joints or 

connections in gathering pipelines. For example, in the production segment of the natural gas system, 

emissions occur at the wellhead, during dehydration, and when the gas is compressed to be transported 

from the wellhead site to a processing plant. CH4 emissions also occur during routine maintenance 

throughout the natural gas system. For example, emissions from the transmission segment include 

intentional blowdown or purge activities during maintenance and inspection.

Abatement options for the natural gas sector generally fall into three categories: equipment 

changes/upgrades, changes in operational practices, and direct inspection and maintenance (DI&M). 

Many abatement options are applicable across all four segments of the natural gas system described in 

Table 2-1. 

• Natural gas emissions from pneumatic control devices are one of the largest sources of CH4

emissions in the natural gas industry. Substituting compressed air for pressurized natural gas 

throughout the natural gas system eliminates the constant bleed of natural gas to the atmosphere. 

• Changing operational practices, such as using pumpdown techniques to remove product (i.e., 

natural gas) from sections of pipeline and the compressor during maintenance and repair, 

reduces the volume of natural gas vented to the atmosphere when components are taken offline. 

• Implementing DI&M programs can eliminate as much as 80 percent of fugitive CH4 emissions 

that result from equipment and pipeline leaks throughout the system. 

The following sections discuss the activity data and emissions factors used to develop baseline 

emissions, abatement options and their costs, and CH4 MACs for natural gas systems for selected 

countries. The chapter concludes with sensitivity analyses on key assumptions and a discussion of 

uncertainties and limitations. 
SECTION II — ENERGY • NATURAL GAS 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES II-17

II.2.2 Baseline Emissions Estimates 

Annual emissions baselines for natural gas systems are calculated using activity factors, activity 

factor drivers, and emissions factors. Each of these factors can be affected by variations in individual 

countries’ production process techniques, the intensity of maintenance schedules, and the age of the 

natural gas system. Table C-7 (see Appendix C) lists the activity factors, emissions factors, and emissions 

for sources in the United States. 

II.2.2.1 Activity Data 

Activity factors and activity factor drivers are used to estimate the population of equipment in each 

segment of the natural gas system. 

Activity Factors 

Activity factors include both the physical number of units and the level of operation/activity of these 

units. These factors inform the underlying population for each type of equipment present in a natural gas 

system. Examples of activity factors include the number of compressors in the production segment, the 

throughput across segments, miles of pipeline, number of blowdowns, and the total number of gas wells. 

Activity factors are used in conjunction with emissions factors (discussed below) to calculate annual 

baseline emissions. This report uses activity factors used to characterize the U.S. natural gas system in 

1992 (USEPA, 1996). 

Activity Factor Drivers 

Activity factor drivers are used to adjust the activity factors from 1992 to reflect changes over time or 

differences between countries. The primary drivers are changes in production and consumption levels, 

but drivers can also include changes in the age or underlying technology of natural gas systems. Activity 

factor drivers determine how the equipment population numbers fluctuate in response to expanding or 

contracting natural gas markets. For example, the number of dehydrators in a natural gas system is 

determined by the number of wells, which is driven by production levels. If production of natural gas 

drops, the number of wells required decreases. This drives down the number of dehydrators in operation 

(or the operating capacity of dehydrators in place), reducing the baseline emissions estimate. 

Historical Activity Data 

Historically, natural gas has been produced by developed countries, which have the technology base 

and capital available to facilitate the development of natural gas industries. In 2001, the FSU and the 

United States accounted for 33 percent of the world’s natural gas production (91.1 trillion cubic feet) 

(USEIA, 2005a). Table 2-2 reports natural gas production by country and region for 1980 through 2003. 

During the past 20 years, natural gas consumption has increased (see Table 2-3). Developing 

countries have experienced the largest increase in consumption in recent years, while industrialized 

countries have experienced small but steady growth over the same period. Currently, developing 

countries consume significantly less natural gas than developed countries; however, this trend is 

projected to change in the next 5 to 10 years. 
SECTION II — ENERGY • NATURAL GAS 

II-18 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

Table 2-2: Natural Gas Production by Country and Region: 1980–2003 (Trillion Cubic Feet) 

Country/Region 1980 1990 1995 2000 2001 2002 2003 

Canada 2.76 3.85 5.60 6.47 6.60 6.63 6.45 

Mexico 0.90 0.90 0.96 1.31 1.30 1.33 1.49 

United States 19.40 17.81 18.60 19.18 19.62 18.93 19.04 

North America 23.06 22.56 25.16 26.97 27.51 26.89 26.98 

Antarctica 0.00 0.00 0.00 0.00 0.00 0.00 0.00 

Central and South America 1.23 2.01 2.58 3.43 3.65 3.72 4.20 

Netherlands 3.40 2.69 2.98 2.56 2.75 2.66 2.58 

Norway 0.92 0.98 1.08 1.87 1.95 2.41 2.59 

United Kingdom 1.32 1.75 2.67 3.83 3.69 3.61 3.63 

Western Europe 7.46 7.24 8.80 10.19 10.27 10.55 10.62 

Russian Federation NA NA 21.01 20.63 20.51 21.03 21.77 

Turkmenistan NA NA 1.14 1.64 1.70 1.89 2.08 

Uzbekistan NA NA 1.70 1.99 2.23 2.04 2.03 

Eastern Europe and FSU 17.06 30.13 25.93 26.22 26.48 27.05 28.00 

Iran 0.25 0.84 1.25 2.13 2.33 2.65 2.79 

Saudi Arabia 0.33 1.08 1.34 1.76 1.90 2.00 2.12 

United Arab Emirates 0.20 0.78 1.11 1.36 1.39 1.53 1.58 

Middle East 1.42 3.72 4.99 7.57 7.98 8.67 9.12 

Algeria 0.41 1.79 2.05 2.94 2.79 2.80 2.91 

Africa 0.69 2.46 3.01 4.44 4.63 4.74 5.07 

Indonesia 0.63 1.53 2.24 2.36 2.34 2.48 2.62 

Malaysia 0.06 0.65 1.02 1.50 1.66 1.71 1.89 

Asia and Oceania 2.44 5.44 7.50 9.48 9.92 10.53 11.19 

World Total 53.35 73.57 77.96 88.29 90.45 92.15 95.18 

Source: USEIA, 2005b. 

FSU = Former Soviet Union; NA = Data unavailable. 

Projected Activity Data 

Production and consumption of natural gas are expected to increase in the near term, with 

developing countries experiencing the largest percentage increases over the next 20 years. Table 2-4 and 

Table 2-5 list projected natural gas production and consumption, respectively, by selected country and 

region from 2010 to 2025. Annual growth in production in Central and South America and Africa is 

expected to approach 5 percent. However, the United States, Eastern Europe, and the FSU are still 

projected to account for more than 50 percent of world natural gas production in 2025 (USEIA, 2004). 

Natural gas is projected to be the fastest growing source of primary energy over the next 20 years. 

Consumption is expected to increase by more than 70 percent (average annual rate of 2.2 percent) from 

2001 to 2025 (USEIA, 2005a). Developing countries will continue to experience the largest percentage 

increases in demand. 
SECTION II — ENERGY • NATURAL GAS 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES II-19

Table 2-3: Natural Gas Consumption by Country and Region: 1980–2003 (Trillion Cubic Feet) 

Country/Region 1980 1990 1995 2000 2001 2002 2003 

Canada 1.88 2.38 2.79 2.95 2.91 3.06 3.21 

Mexico 0.80 0.92 1.04 1.40 1.40 1.50 1.82 

United States 19.88 19.17 22.21 23.33 22.24 23.01 22.38 

North America 22.56 22.47 26.04 27.68 26.55 27.57 27.41 

Central and South America 1.24 2.02 2.58 3.30 3.54 3.56 3.82 

France 0.98 1.00 1.18 1.40 1.47 1.59 1.54 

Germany NA NA 3.17 3.10 3.24 3.20 3.32 

Italy 0.97 1.67 1.92 2.50 2.51 2.49 2.72 

Netherlands 1.49 1.54 1.70 1.73 1.77 1.76 1.78 

United Kingdom 1.70 2.06 2.69 3.37 3.34 3.31 3.36 

Western Europe 8.66 10.50 12.76 15.13 15.51 15.87 16.43 

Russian Federation NA NA 14.51 14.13 14.41 14.57 15.29 

Ukraine NA NA 2.97 2.78 2.62 2.78 3.02 

Uzbekistan NA NA 1.35 1.51 1.60 1.64 1.67 

Eastern Europe and FSU 15.86 27.83 23.04 22.80 23.30 23.68 24.97 

Iran 0.23 0.84 1.24 2.22 2.48 2.80 2.79 

Saudi Arabia 0.33 1.08 1.34 1.76 1.90 2.00 2.12 

United Arab Emirates 0.11 0.66 0.88 1.11 1.15 1.29 1.34 

Middle East 1.31 3.60 4.74 6.82 7.05 7.63 7.86 

Africa 0.74 1.35 1.69 2.04 2.28 2.45 2.55 

China 0.51 0.49 0.58 0.93 1.05 1.13 1.18 

Indonesia 0.20 0.55 1.06 1.08 1.18 1.20 1.23 

Japan 0.90 1.85 2.21 2.84 2.84 2.94 3.05 

Asia and Oceania 2.52 5.61 7.79 10.43 11.08 11.76 12.46 

World Total 52.89 73.37 78.64 88.21 89.31 92.51 95.50 

Source: USEIA, 2005b. 

FSU = Former Soviet Union; NA = Data unavailable. 

II.2.2.2 Emissions Factors and Related Assumptions 

Emissions factors in the natural gas sector are defined as the rate of CH4 emissions from a facility or 

piece of equipment or from normal operations and routine maintenance. Estimated emissions factors are 

used in conjunction with activity factors and activity factor drivers to generate baseline emissions 

estimates by country. Table 2-6 reports estimated emissions factors by country, provided by IPCC’s 

Revised 1996 IPCC Guidelines for National Greenhouse Gas Inventories: Reference Manual. These emissions 

factors represent the average estimated emissions factor across all segments of the natural gas system. 

The system-level emissions factors in Table 2-6 are used to calculate country-specific baseline 

emissions (see Section II.2.2.3) for countries outside the United States. For the United States, a more 

detailed set of emissions factors is used to calculate baseline emissions. Appendix Table C-7 presents the 

individual facility and equipment emissions factors estimated for the U.S. natural gas system, adapted 

from the USEPA report Methane Emissions form the Natural Gas Industry (USEPA, 1996). 

This section discusses the source of the emissions factors used to develop country-specific baseline 

emissions. 
SECTION II — ENERGY • NATURAL GAS 

II-20 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

Table 2-4: Projected Natural Gas Production by Country and Region: 2010–2025 (Trillion Cubic Feet)

Country/Region 2010 2015 2020 2025 

Average Annual 

Percentage Change, 

2001–2025 

Canada 7.6 7.5 7.1 7.5 0.5 

Mexico 1.5 1.6 1.9 2.1 2.0 

United States 20.5 21.6 23.8 24.0 0.8 

North America 29.6 30.6 32.8 33.6 0.8 

Central and South America 5.5 7.1 8.6 10.6 4.6 

Western Europe 9.0 9.0 8.9 9.8 –0.2 

Eastern Europe and FSU 31.0 35.7 40.4 45.3 2.2 

Middle East 9.8 12.1 15.6 18.8 3.5 

Africa 8.1 9.9 11.9 14.1 4.8 

China 1.6 1.9 2.3 3.1 4.5 

Asia 12.5 14.2 16.3 18.8 2.6 

World Total 105.5 118.5 134.5 151.0 2.1 

Source: USEIA, 2004. 

FSU = Former Soviet Union. 

Table 2-5: Projected Natural Gas Consumption by Country and Region: 2010–2025 (Trillion Cubic Feet) 

Country/Region 2010 2015 2020 2025 

Average Annual 

Percentage Change, 

2001–2025 

Canada 3.9 4.3 4.6 4.7 2.0 

Mexico 1.8 2.2 2.6 3.0 3.0 

United States 25.6 28.3 30.4 30.9 1.3 

North America 31.3 34.8 37.6 38.6 1.5 

Brazil 0.9 1.3 1.7 2.1 6.8 

Other Central/South America 3.8 4.3 4.8 5.4 2.4 

Western Europe 17.3 19.0 20.4 22.4 1.8 

Russian Federation 16.2 17.9 19.5 20.7 1.5 

Eastern Europe 4.0 4.6 5.2 5.8 3.5 

FSU 25.6 29.0 31.0 33.3 2.0 

Middle East 10.6 12.6 14.5 16.6 3.1 

Africa 3.1 4.1 4.9 6.0 4.0 

China 2.6 3.4 4.2 6.5 7.8 

Emerging Asia 10.6 13.3 16.3 20.7 4.3 

World Total 111.4 127.9 141.6 156.2 2.3 

Source: USEIA, 2005c. 

FSU = Former Soviet Union. 
SECTION II — ENERGY • NATURAL GAS 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES II-21

Table 2-6: IPCC Estimated Emissions Factors from Natural Gas by Region 

Emissions Factors by Industry Segment 

(kg/petajoule) 

Country/Region Production Consumption 

Eastern Europe/FSUa 392,800 527,900 

Other oil-exporting countriesb 67,795 228,310 

United States and Canada 71,905 88,135 

Western Europec 20,900 84,500 

Rest of the worldd 67,795 228,310 

Source: IPCC, 1996. Adapted from Reference Manual Tables 1-60, 1-61, 1-62, 1-63, and 1-64. 

FSU = Former Soviet Union 

a Includes Albania, Bulgaria, Czech and Slovak Republics, Hungary, Poland, Romania, and the former Yugoslavia. 

b Includes Algeria, Nigeria, Venezuela, Indonesia, Iran, Iraq, Kuwait, Saudi Arabia, United Arab Emirates, Ecuador, and Mexico. 

c Includes Austria, Belgium, Denmark, Faroe Islands, Finland, France, Germany, Gibraltar, Greece, Iceland, Ireland, Italy, Luxembourg, Malta, 

the Netherlands, Norway, Portugal, Spain, Sweden, Switzerland, and the United Kingdom. 

d Includes Asia, Africa, Middle East, Oceania, and Latin America. 

Historical Emissions Factors 

The United States conducted a study to measure and estimate emissions factors for all components in 

its national infrastructure (USEPA, 1996). This study measured or estimated emissions factors for more 

than 100 pieces of natural gas equipment, such as gas wells, compressors, pipeline, and system upsets. 

The study was conducted in 1992, and the emissions factors were revised and published in 1996. 

Table C-7 (see Appendix C) lists the study’s emissions factors by component and segment of the 

infrastructure. These emissions factors are used to calculate the U.S. baseline emissions estimate (see 

Table 2-7). For all other countries, IPCC systems emissions factors (Table 2-6) were used to develop 

baseline emissions estimates. 

Table 2-7: Baseline Emissions for Natural Gas Systems for Selected Countries: 1990–2000 (MtCO2eq) 

Country 1990 1995 2000 

Russian Federation 334.3 240.6 165.3 

United States 143.9 148.0 145.7 

Iran 19.4 29.1 34.6 

Mexico 22.7 25.3 37.4 

Ukraine 78.3 81.8 86.9 

Turkmenistan 19.5 16.7 24.3 

Nigeria 12.5 17.6 37.8 

Venezuela 29.8 34.8 37.7 

Turkey 19.9 28.5 38.7 

India 8.0 12.5 15.8 

United Arab Emirates 18.9 26.7 33.2 

Uzbekistan 27.2 30.3 34.8 

Indonesia 31.3 41.4 42.1 

Canada 25.4 34.3 37.3 

Argentina 8.0 10.9 14.9 

Rest of the world 132.0 145.3 186.0

World Total 931.0 923.8 972.4

Source: USEPA, 2006. 
SECTION II — ENERGY • NATURAL GAS 

II-22 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

Projected Emissions Factors and Related Assumptions 

Over time, the USEPA estimates that the proportional growth in baseline CH4 globally will slow 

relative to the growth in overall production and consumption. Emissions factors in mature natural gas 

systems are projected to increase because of equipment age and fatigue. However, this increase will be 

counterbalanced by rapidly expanding industries in developing countries that will employ state-of-theart technology when constructing natural gas infrastructures. 

For example, China is in the early stages of developing a natural gas infrastructure. China’s use of 

state-of-the-art technology supplied by the United States, the European Union (EU), and Japan will result 

in low emissions factors, and these low emissions factors will constrain the growth in China’s national 

baseline emissions over time. 

II.2.2.3 Emissions Estimates and Related Assumptions 

The USEPA estimates the emissions contribution of each segment in the natural gas system by 

multiplying emissions factors (EF) by associated activity factors (AF) and then summing them, as shown 

below: 

Country Total Emissions = Production (EF × AF) + Processing (EF × AF) + (2.1) 

Transport (EF × AF) + Storage (EE × AF) + 

Distribution (EF × AF)

From Equation (2.1), individual country baseline estimates using natural gas production and 

consumption data are coupled with the IPCC system emissions factors presented in Table 2-6. This 

section discusses the historical and projected changes in the baseline emissions estimates. 

Historical Emissions Estimates 

Baseline emissions are built using publicly available reports produced by the countries themselves. 

IPCC guidelines and methods were used to estimate emissions in each country, ensuring comparability 

across countries. Table 2-7 presents the countries with the largest historical CH4 baseline emissions for 

1990, 1995, and 2000. CH4 emissions increased worldwide from 1990 to 2000 at an average annual rate of 

3 percent. 

Projected Emissions Estimates 

Overall, world CH4 emissions are expected to increase during the next 20 years at an average annual 

rate of 5.7 percent (USEPA, 2003a), reflecting a projected increase in natural gas use as a share of total 

energy consumption. Table 2-8 presents the predicted CH4 baseline emissions for the largest emitting 

countries in the global natural gas sector. Developing countries will experience the largest percentage 

increases in emissions, which closely parallel expected increases in consumption and production of 

natural gas. However, the level of technology employed in building new infrastructure will help 

constrain baseline emissions for these countries. 
SECTION II — ENERGY • NATURAL GAS 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES II-23

Table 2-8: Projected Baseline Emissions for Natural Gas Systems for Selected Countries: 2005–2020 

(MtCO2eq) 

Country 2005 2010 2015 2020 

Russian Federation 171.9 178.6 185.8 193.1 

United States 124.3 138.6 151.0 164.8 

Iran 56.8 74.0 96.4 125.3 

Mexico 49.5 64.0 82.6 111.4 

Ukraine 90.4 93.9 97.7 101.5 

Turkmenistan 46.2 72.1 83.2 93.9 

Nigeria 49.1 59.2 73.3 89.4 

Venezuela 45.2 50.7 63.0 84.8 

Turkey 50.2 56.6 62.9 75.5 

India 25.8 35.7 49.5 61.4 

United Arab Emirates 38.7 47.4 52.8 59.7 

Uzbekistan 39.6 44.3 45.4 46.8 

Indonesia 46.8 48.0 46.3 45.2 

Canada 37.3 38.2 39.8 41.1 

Argentina 14.9 16.7 20.9 28.1 

Rest of the world 213.8 253.4 313.0 373.8

World Total 1,100.4 1,271.5 1,463.7 1,695.8

Source: USEPA, 2006. 

II.2.3 Cost of CH4 Emissions Reductions from Natural Gas Systems 

Capital costs, annual costs, and annual benefits for individual abatement options are obtained from 

the USEPA’s economic cost model. The economic cost model incorporates activity and emissions factors 

published by the USEPA and the Gas Research Institute (GRI) (USEPA, 1996). The USEPA’s economic 

cost model reports one-time capital costs, annual operating costs, and reduction efficiencies for 118 

different abatement options applied across the four sectors: production, processing, transmission and 

storage, and distribution. Options range from upgrading compressors and pipes to enhancing inspection 

and detection techniques. The number of options by sector is presented in Table 2-9. Table C-8 (in 

Appendix C) contains a brief description of the major categories of natural gas abatement options. 

It should be noted that a large number of abatement options for the natural gas sector are substitutes 

for each other. Thus, there may be several options for reducing emissions for a particular piece of 

equipment, but only one may be selected. For example, DI&M of gas wells is substitutable with enhanced 

DI&M. In developing the MACs, the model chooses between substitute options, selecting the option with 

the lowest breakeven price. 

Table 2-9: Prevalence of Abatement Options by Infrastructure Component 

Infrastructure Component Total 

Production 39 

Processing 2 

Transmission and storage 51 

Distribution 26 

Source: USEPA, 2000. 
SECTION II — ENERGY • NATURAL GAS 

II-24 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

II.2.3.1 Abatement Option Opportunities 

This section presents a general overview of the applicable abatement options for each segment of the 

natural gas system, followed by a more detailed discussion of the costs and benefits of selected abatement 

options. Engineering cost and benefit estimates represent equipment and operating costs in the United 

States for 1999. Whereas some abatement options are unique to a specific segment of the natural gas 

system, many are applicable in multiple segments. 

Production Abatement Options 

The production segment of the natural gas sector consists of wells, compressors, dehydrators, 

pneumatic devices, chemical injection pumps, heaters, meters, pipeline, and central gathering facilities. 

Abatement technologies associated with the production segment include 

• catalytic converters for select well field engines and compressors, 

• replacement of wet seals with dry seals in centrifugal compressors, 

• direct/enhanced inspection and maintenance at production sites, 

• flash tank separator installation in glycol dehydration systems, 

• replacement of high-bleed pneumatic devices, and 

• optimization of glycol recirculation rates. 

One example of technology available to the production segment reduces glycol recirculation rates. 

Producers use triethylene glycol (TEG) in dehydrators to remove water from the natural gas coming out 

of the ground to meet pipeline quality standards. “Dry” TEG is combined with natural gas to remove 

moisture content before the natural gas is sold into a pipeline. The “rich” TEG then enters a boiler, where 

the foreign substances are evaporated and emitted into the atmosphere and the cycle repeats itself. The 

rate at which this process occurs is directly proportional to the amount of CH4 emitted from glycol 

dehydrators. Production fields become less productive over time, but the rate at which the TEG 

recirculates is commonly based on the initial rate of production. As the well site matures, the TEG 

circulation rate becomes oversized. Recirculation can be recalculated to achieve sufficient moisture 

removal from the gas and minimize the release of CH4 from the system. The following are the cost 

components for this abatement option: 

• Capital Costs. This abatement option requires minimal or no additional equipment. However, 

similar to inspection and maintenance programs, the option is labor intensive, with the 

calculations and circulation adjustments conducted by engineering staff.

• Annual Costs. Annual costs primarily include the labor required to calculate new optimal 

recirculation rates each year as the well site becomes less productive.

• Cost Savings/Benefits. More CH4 is brought to market for sale.

Processing Abatement Options 

The processing segment consists of gas plant facilities that incorporate the use of vessels, 

dehydrators, compressors, acid gas removal (AGR) units, heaters, and pneumatic devices. Abatement 

technologies associated with the processing segment include 

• fuel gas retrofit for reciprocating compressors, 

• replacement of wet seals with dry seals in centrifugal compressors, 

• conversion of gas pneumatic controls to instrument air, and 

• DI&M at gas processing plants. 
SECTION II — ENERGY • NATURAL GAS 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES II-25

One example of abatement technology available to the processing segment converts gas pneumatic 

controls to compressed instrument air systems. Processing plants use pneumatic control systems to 

monitor various gas and liquid levels. As part of their normal operations, these devices release or bleed 

CH4 into the atmosphere. Processing plants can substitute compressed air for natural gas within 

pneumatic systems. The following are the cost components for this abatement option: 

• Capital Costs. Capital costs include the purchase and installation of a compressor, dehydrator, 

and volume tank—the major components of the instrument air system. Depending on the size of 

the gas processing plant, capital costs are estimated to be between $4,500 and $35,000 for the 

required capital equipment. 

• Annual Costs. Annual costs include the annual energy, materials, and labor required to operate 

and monitor the equipment used in the compressed instrument air system. Annual energy costs 

are determined by the size of the compressor. Annual servicing costs range from $800 to $3,600 

per year. 

• Cost Savings/Benefits. By replacing natural gas with compressed instrument air, CH4 is no 

longer being vented during normal operations. The benefit is the market value of CH4 abated. 

Transmission Abatement Options 

The transmission segment of a natural gas system consists of transmission pipeline networks, 

compressor stations, and meter and pressure-regulating stations. The following are abatement 

technologies available to the transmission segment: 

• conversion of gas pneumatic controls to instrument air, 

• use of pipeline pumpdown techniques to lower gas line pressure before maintenance, 

• DI&M at compressor stations and surface facilities, 

• replacement of wet seals with dry seals in centrifugal compressors, and 

• replacement of compressor rod packing systems. 

One example of the abatement options available to the transmissions segment is DI&M at compressor 

stations. Compressor stations amplify pressure at several stages along a transmission natural gas pipeline 

to combat pressure loss over long distances. Over time, compressors and other related components 

become fatigued and may leak CH4. The DI&M program reduces CH4 emissions at compressor stations 

by identifying leaks and focusing maintenance on the largest leaks. The following are the cost 

components for this abatement option: 

• Capital Costs. Capital costs include the cost of purchasing a leak detection device, which varies 

widely depending on the type of device used. The cost of screening devices ranges from $1,000 to 

$20,000. The cost of more sensitive sampling devices ranges from $1,000 to $10,000. 

• Annual Costs. Annual costs include the cost of labor and materials to develop a maintenance 

schedule and implement the survey and maintenance annually. Annual costs account for the 

majority of costs associated with implementing this abatement option. 

• Cost Savings/Benefits. Cost savings are approximately $3 per thousand cubic feet (Mcf) of CH4

recovered. The savings will depend on the intensity of the DI&M program and whether the leak, 

once detected, is fixed. The average station leak rate is approximately 41,000 Mcf per year, and 

the average annual cost savings is $88,000 at a gas price of $3 per Mcf (USEPA, 2003b). 
SECTION II — ENERGY • NATURAL GAS 

II-26 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

Distribution Abatement Options 

The distribution segment consists of main and service pipeline networks, meter and pressureregulating stations, pneumatic devices, and customer meters. Abatement technologies available to the 

distribution segment include the 

• use of hot taps in service pipeline connections, 

• DI&M at gate stations, 

• use of composite wrap for nonleaking pipeline defects, and 

• use of a pipeline pumpdown technique to lower gas line pressure before maintenance. 

An example abatement option available to the distribution segment is the use of a pipeline 

pumpdown technique when performing maintenance on segments of distribution pipeline. Operators 

routinely reduce line pressure and discharge gas from a pipeline during maintenance and repair 

activities. Using a pumpdown technique, which requires the use of inline and/or portable compressors to 

depressurize the section of pipeline, operators can mitigate CH4 emissions. The following are the cost 

components for this abatement option: 

• Capital Costs. Capital costs include the one-time costs of purchasing a portable compressor. The 

cost of this compressor varies by size and ranges from $500,000 (300 psi) to $3,000,000 (1,000 psi). 

Installation and freight costs are determined by the size of the compressor purchased. 

• Annual Costs. Annual costs include fuel/energy, maintenance, and labor costs. Average energy 

costs vary based on the compressor’s horsepower rating. Maintenance costs range from $4 to $9 

per horsepower per month. 

• Cost Savings. Cost savings will vary depending on the volume of gas available for recovery. The 

volume of gas available is determined by the length of pipeline to be repaired and the flow rate of 

gas during normal operations. 

II.2.4 Results 

This section presents the EMF-21 study’s MAC results in tabular format. 

II.2.4.1 Data Tables and Graphs 

Table 2-10 presents the average breakeven price and the reduction in absolute and percentage terms 

for the mitigation options discussed in Section II.2.3.1. 

The EMF regional baselines and MAC results of the EMF-21 study are presented in Tables 2-11 and 2-

12 for 2010 and 2020 using a base energy price, a 10 percent discount rate, and a 40 percent tax rate. These 

MACs represent static percentage reductions in baselines for individual regions/countries and represent 

the official MACs used in climate change modeling. Figure 2-2 provides MACs for the five EMF 

countries/regions with the largest estimated emissions for natural gas systems in 2020. 

The MACs presented in this section represent static abatement curves using breakeven prices built on 

the assumption of fixed mitigation cost and aggregate countrywide natural gas statistics. Appendix C to 

this chapter presents more recent efforts to develop an alternative framework for conducting MAC 

analysis that addresses the limitations of the EMF-21 MAC analysis. 
SECTION II — ENERGY • NATURAL GAS 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES II-27

Table 2-10: Natural Gas MACs for Countries Included in the Analysis 

Technology 

Breakeven 

Cost 

($/tCO2eq) 

Emissions 

Reduction (% 

from 

baseline) 

Emissions 

Reduction in 

2010 

(MtCO2eq) 

Emissions 

Reduction in 

2020 

(MtCO2eq) 

Assuming a 10% discount rate and a 40% tax rate 

P&T—use gas turbines instead of reciprocating 

engines 

$113.36 4% 0.21 0.27 

P&T—compressors altering start-up procedure 

during maintenance 

–$15.22 0% 0.01 0.01 

Prod-D I&M (chemical inspection pumps) $121.98 0% 0.01 0.01 

Prod-D I&M (enhanced) $836.05 0% 0.01 0.01 

Prod-D I&M (offshore) $49.51 0% 0.01 0.01 

Prod-D I&M (onshore) $682.60 0% 0.01 0.01 

Prod-D I&M (pipeline leaks) $55.82 1% 0.07 0.09 

Installation of electric starters on compressors 

(production) 

$9,829.72 0% 0.00 0.00 

Installation of flash tank separators (production) $85.47 2% 0.09 0.10 

Installation of plunger lift systems in gas wells $3,233.11 0% 0.00 0.00 

Portable evacuation compressor for pipeline venting 

(production) 

$178.89 0% 0.00 0.00 

Reducing the glycol circulation rates in dehydrators 

(production) 

–$25.03 0% 0.01 0.02 

Replace high-bleed pneumatic devices with 

compressed air systems (production) 

$85.36 5% 0.23 0.27 

Replace high-bleed pneumatic devices with lowbleed pneumatic devices (production) 

–$12.22 4% 0.20 0.23 

Surge vessels for station/well venting (production) $8,774.06 0% 0.00 0.00 

Dry seals on centrifugal compressors (P&T) $36.75 3% 0.16 0.20 

Fuel gas retrofit for blowdown valve –$26.67 2% 0.08 0.10 

Reducing the glycol circulation rates in dehydrators 

(P&T) 

–$27.55 0% 0.01 0.01 

Catalytic converter (P&T) $76.81 3% 0.16 0.20 

P&T-D I&M (compressor stations) –$25.24 0% 0.02 0.03 

P&T-D I&M (compressor stations: enhanced) –$24.45 0% 0.02 0.03 

P&T-D I&M (enhanced: storage wells) $100.27 0% 0.00 0.00 

P&T-D I&M (pipeline: transmission) $2,863.14 0% 0.00 0.00 

P&T-D I&M (wells: storage) $79.74 0% 0.00 0.00 

Installation of flash tank separators (P&T) $7.57 0% 0.01 0.01 

Portable evacuation compressor for pipeline venting 

(P&T) 

$178.89 2% 0.10 0.13 

Static-pacs on reciprocating compressors (P&T) $34.30 0% 0.01 0.02 

(continued) 
SECTION II — ENERGY • NATURAL GAS 

II-28 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

Table 2-10: Natural Gas MACs for Countries Included in the Analysis (continued) 

Technology 

Breakeven 

Cost 

($/tCO2eq) 

Emissions 

Reduction (% 

from 

baseline) 

Emissions 

Reduction in 

2010 

(MtCO2eq) 

Emissions 

Reduction in 

2020 

(MtCO2eq) 

Replace high-bleed pneumatic devices with 

compressed air systems (P&T) 

$88.69 2% 0.09 0.11 

Replace high-bleed pneumatic devices with lowbleed pneumatic devices (P&T) 

–$12.22 2% 0.08 0.10 

Surge vessels for station/well venting (P&T) $8,774.06 1% 0.08 0.09 

D-D I&M (distribution) –$23.20 2% 0.12 0.15 

D-D I&M (enhanced: distribution) $21.02 4% 0.22 0.27 

Electronic monitoring at large surface facilities (D) $0.76 5% 0.27 0.33 

Replacement of cast iron/unprotected steel pipeline 

(D) 

$19,347.78 7% 0.34 0.42 

Replacement of unprotected steel services (D) $461,544.32 3% 0.14 0.17 

Source: USEPA, 2003a. Adapted from Natural Gas Sector technology tables in Appendix B. 

D = Distribution; I&M = Inspection and maintenance; P = Production; T = Transmission. 

Table 2-11: Baseline Emissions by EMF Regional Grouping: 2000–2020 (MtCO2eq) 

Country/Region 2000 2010 2020 

Africa 65.7 95.7 144.5 

Annex I 517.3 556.9 639.2 

Australia/New Zealand 6.1 9.6 15.2 

Brazil 1.8 6.9 14.9 

China 1.9 5.8 13.2 

Eastern Europe 8.5 12.2 17.7 

EU-15 25.2 25.4 26.4 

India 15.8 35.7 61.4 

Japan 0.4 0.4 0.4 

Mexico 37.4 64.0 111.4 

Non-OECD Annex I 255.9 277.0 299.6 

OECD 301.9 349.8 459.4 

Russian Federation 165.3 178.6 193.1 

South & SE Asia 71.7 85.5 105.8 

United States 145.7 138.6 164.8 

World Total 972.4 1,271.5 1,695.8 

Source: USEPA, 2006. 

EU-15 = European Union; OECD = Organisation for Economic Co-operation and Development. 

Note: World Total does not equal the sum of the countries listed in this table because the regional groupings are a subset of the full EMF 

regional grouping list. See Appendix A of this report for the full EMF list of countries by region. 
SECTION II — ENERGY • NATURAL GAS 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES II-29

Table 2-12: Natural Gas MACs for Countries Included in the Analysis 

Percentage Reduction from Baseline (tCO2eq) 

2010 2020 

Country/Region $0 $15 $30 $45 $60 $0 $15 $30 $45 $60 

Africa 20.38% 29.98% 37.85% 43.62% 56.03% 20.38% 29.98% 37.85% 43.62% 56.03% 

Annex I 9.60% 24.21% 31.68% 35.12% 50.46% 8.98% 22.63% 29.62% 32.83% 47.18% 

Australia/New Zealand 14.44% 20.06% 29.35% 36.94% 56.54% 14.44% 20.06% 29.35% 36.94% 56.54% 

Brazil 16.64% 25.42% 36.87% 43.54% 57.79% 16.64% 25.42% 36.87% 43.54% 57.79% 

China 17.05% 36.78% 43.33% 44.11% 45.92% 17.05% 36.78% 43.33% 44.11% 45.92% 

Eastern Europe 19.05% 25.84% 34.03% 34.22% 48.71% 19.05% 25.84% 34.03% 34.22% 48.71% 

EU-15 11.58% 18.38% 28.39% 29.01% 49.18% 11.58% 18.38% 28.39% 29.01% 49.18% 

India 10.70% 28.15% 36.44% 43.49% 58.74% 10.70% 28.15% 36.44% 43.49% 58.74% 

Japan 28.05% 28.12% 32.51% 46.17% 61.10% 28.05% 28.12% 32.51% 46.17% 61.10% 

Mexico 11.06% 23.15% 37.02% 43.55% 57.62% 11.06% 23.15% 37.02% 43.55% 57.62% 

Non-OECD Annex I 6.26% 27.29% 33.72% 35.50% 48.29% 6.09% 26.56% 32.81% 34.54% 46.99% 

OECD 13.86% 20.73% 29.85% 35.60% 53.75% 12.14% 18.17% 26.16% 31.20% 47.11% 

Russian Federation 3.75% 26.85% 33.14% 35.11% 48.42% 3.75% 26.85% 33.14% 35.11% 48.42% 

South & SE Asia 11.51% 29.75% 37.75% 43.61% 56.22% 11.51% 29.75% 37.75% 43.61% 56.22% 

United States 14.52% 19.24% 28.14% 35.47% 54.76% 14.52% 19.24% 28.14% 35.47% 54.76% 

World Total 10.11% 24.98% 32.95% 37.90% 53.36% 10.19% 25.25% 33.24% 38.40% 53.81% 

Source: USEPA, 2003a. 

EU-15 = European Union. 

Figure 2-2: EMF MACs for Top Five Emitting Countries/Regions from Natural Gas: 2020 

Source: USEPA, 2003a. 

Note: This table was constructed using percentage reductions from USEPA (2003), with baselines from USEPA (2005). 

-$10

$0

$10

$20

$30

$40

$50

0 10 20 30 40 50 60 70 80

Absolute Reduction (MtCO2eq)

$/tCO2eq

Mexico

Africa

Russian Federation

South & SE Asia

United States
SECTION II — ENERGY • NATURAL GAS 

II-30 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

II.2.5 Summary 

The methodology and data discussed in this section describe the MAC analysis conducted for the 

natural gas sector by the EMF-21 study. MACs for 2010 and 2020 were estimated based on aggregated 

industry data from each country or region. The MACs represent static estimates of potential CH4

mitigation from natural gas systems based on available information regarding infrastructure and 

country-reported emissions estimates provided through the United Nation’s Framework Convention on 

Climate Change emissions inventory reports. 

II.2.6 References 

Intergovernmental Panel on Climate Change (IPCC). 1996. Revised 1996 IPCC Guidelines for National 

Greenhouse Gas Inventories: Reference Manual (Volume 3). Available at <http://www.ipcc-nggip.iges.or. 

jp/public/gl/invs6.htm>. As obtained on April 26, 2004. 

U.S. Department of Energy (USDOE), Energy Information Administration (USEIA). 2004. International 

Energy Outlook 2004. Table 11. DOE/EIA-0484(2004) Washington, DC: USEIA. Available at 

<http://tonto.eia.doe.gov/FTPROOT/forecasting/0484(2004).pdf>. 

U.S. Department of Energy (USDOE), Energy Information Administration (USEIA). 2005a. International 

Energy Annual 2003. Table 2.4. Washington, DC: USEIA. Available at <http://www.eia.doe.gov/ 

iea/ng.html>. As obtained on May 2, 2006. 

U.S. Department of Energy (USDOE), Energy Information Administration (USEIA). 2005b. International 

Energy Annual 2003. Table 1.3. Washington, DC: USEIA. Available at <http://www.eia.doe.gov/ 

iea/ng.html>. As obtained on May 2, 2006. 

U.S. Department of Energy (USDOE), Energy Information Administration (USEIA). 2005c. International 

Energy Outlook 2005. DOE/EIA-0484(2005) Table A5. Washington, DC: USEIA. Available at 

<http://www.eia.doe.gov/oiaf/ieo/>. As obtained on May 2, 2006. 

U.S. Environmental Protection Agency (USEPA). 1996. Methane Emissions from the Natural Gas Industry 

Volume 2: Technical Report. EPA-600/R-96-080b. Washington, DC: USEPA. 

U.S. Environmental Protection Agency (USEPA). 2000. Spreadsheet Cost Model. Washington, DC: USEPA. 

U.S. Environmental Protection Agency (USEPA). 2003a. International Analysis of Methane and Nitrous Oxide 

Abatement Opportunities: Report to Energy Modeling Forum, Working Group 21. Appendices. Washington, 

DC: USEPA. Available at <http://www.epa.gov/methane/intlanalyses.html>. As obtained on 

September 27, 2004. 

U.S. Environmental Protection Agency (USEPA). 2003b. Lessons Learned From Natural Gas STAR Partners. 

Washington, DC: USEPA. Available at <http://www.epa.gov/gasstar/lessons.htm>. As obtained on 

August 19, 2003. 

U.S. Environmental Protection Agency (USEPA). 2006. Global Anthropogenic Non-CO2 Greenhouse Gas 

Emissions: 1990–2020. Washington, DC: USEPA. 
SECTION II — ENERGY • OIL 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES II-31

II.3 Oil Sector 

orldwide CH4 emissions from oil production accounted for more than 57 MtCO2eq in 2000 

(USEPA, 2006). Oil is the 11th largest source of anthropogenic CH4 emissions globally. The 

USEPA estimates that oil production contributed approximately 0.5 percent of total global 

CH4 emissions in 2000 (USEPA, 2006). Combined, Mexico, Eastern Europe, the United States, and China 

accounted for approximately 67 percent of the world’s CH4 emissions from oil (Figure 3-1). Global CH4

emissions from oil are expected to grow by approximately 104 percent between 2005 and 2020. 

Figure 3-1: CH4 Emissions from Oil Production by Country: 2000–2020 

Source: USEPA, 2006. 

II.3.1 Introduction 

Oil production begins by extracting crude oil either from underground production field wells 

(onshore) or platform oil derricks (offshore). The process of extracting oil involves drilling a deep well to 

access an oil reservoir underground. Once a well is drilled, compressors are used to pressurize the well, 

allowing the crude oil to exit the well through the vertical shaft. The compressed oil is transported via 

pipeline to a processing system and finally to a storage tank. Marine, rail, and truck tankers are the three 

major forms of transportation used by the oil sector to move crude oil from the site of production to the 

refinery. Pumping stations regulate the transfer of crude oil from storage tanks or pipelines onto 

transport tankers. 

CH4 emissions are associated with crude oil production, transportation, and refining operations. 

These oil production segments release CH4 into the atmosphere as fugitive emissions, emissions from 

operational upsets, and emissions from fuel combustion (USEPA, 2004). In the United States, the largest 

emissions sources include high-bleed pneumatic devices, flaring, chemical injection pumps, and oil 

wellheads for light crude (USEPA, 2004). Emissions from oil production fields accounted for more than 97 

W 

0

20

40

60

80

100

120

140

2000 2010 2020

Year

MtCO2eq

China

United States

Eastern Europe

Mexico

Rest of the world
SECTION II — ENERGY • OIL 

II-32 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

percent of the total oil industry emissions. The remaining 3 percent was emitted from crude oil 

refinement (2 percent) and transportation (1 percent) (USEPA, 2004). 

II.3.1.1 Emissions from Production Field Operations 

During production field operations, CH4 is released into the atmosphere via venting, accidental leaks, 

and fuel combustion. The USEPA suggests that the majority of emissions come from oil wellheads, 

storage tanks, and related field processing equipment such as compressors and chemical and injection 

pumps. CH4 emissions from storage tanks, a dominant source of emissions, are created when the CH4

entrained in crude oil under high pressure volatilizes as the oil enters the tank where it is stored at 

atmospheric pressure. Equipment leaks and vessel blowdowns during routine maintenance make up the 

second largest share of emissions from oil systems. The remaining emissions from field operations are 

associated with fugitive leaks and combustion through flares (USEPA, 2004). 

Saudi Arabia and the United States were the two largest producers of oil in 2000, producing a 

reported 9.2 and 8.1 million barrels of crude oil per day, respectively. However, they do not have the 

largest CH4 emissions from oil. Onshore production of oil generates less CH4 emissions than offshore oil 

operations, because CH4 produced onshore is more readily captured and transported for use. Oil 

production in many of the Organization of the Petroleum Exporting Countries (OPEC) members, 

including Saudi Arabia, consists primarily of onshore production operations. In contrast, a large share of 

the oil production in Mexico comes from offshore platforms. 

II.3.1.2 Emissions from Crude Oil Transportation 

Venting activities in transport tanks and marine vessel loading operations account for the majority of 

emissions in the transportation segment. Fugitive emissions from floating roof tanks account for the 

remainder of oil transportation emissions in the United States (USEPA, 2004). 

II.3.1.3 Emissions from Crude Oil Refining 

Most of the CH4 entrained in crude oil has already escaped prior to the refining stage. Vented 

emissions that occur during normal operations account for the majority of emissions from this sector. 

Examples include refinery system blowdowns during routine maintenance and asphalt blowing. Fugitive 

leaks and combustion emissions are also a source of emissions. Most fugitive emissions come from leaks 

in a refinery’s fuel gas system. Combustion emissions result from small amounts of unburned CH4 in 

process heater stacks and from unburned CH4 in engine exhausts and flares (USEPA, 2004). 

II.3.1.4 Abatement Options 

Three abatement options are discussed for the oil sector: flaring, direct use, and reinjection of gas into 

oil fields. The installation of a flaring system results in an estimated 98 percent reduction in fugitive 

emissions but can be costly in an offshore environment because of technical, environmental, and safety 

concerns. Direct use is applicable primarily to oil platforms, because CH4 captured onshore is typically 

injected into the pipeline system (and is reflected in the baseline emissions). Reinjection of CH4 back into 

the oil production field is an alternative to flaring or direct use and can enhance future oil recovery. 

The following sections discuss the activity data and emissions factors used to develop baseline 

emissions, abatement options and their costs, and CH4 MACs for oil production for selected countries. 

The chapter concludes with sensitivity analysis of key assumptions and a discussion of uncertainties and 

limitations. 
SECTION II — ENERGY • OIL 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES II-33

II.3.2 Baseline Emissions Estimates 

Baseline emissions from the oil sector are composed of emissions from production field operations, 

crude oil transportation, and crude oil refining. These emissions are classified either as fugitive emissions, 

vented emissions from operations, or emissions from fuel combustion (USEPA, 2004). 

A country’s baseline emissions estimate is the product of activity factors and emissions factors. The 

following section provides an overview of activity and emissions factors and concludes with a discussion 

of historical and projected baselines by type of equipment used. 

II.3.2.1 Activity Factors 

Activity factors characterize a given industry’s size, either as the number of units (e.g., number of 

wells or miles of pipeline) or the flow through the units (million barrels [MMbbl] per day or year). The 

United States tracks 70 different activity factors for the oil industry. Some of these activity factors change 

annually in proportion to rates of crude oil production, transportation, and refinery runs, while others 

change in proportion to the number of facilities such as oil wells and petroleum refineries (USEPA, 2004). 

A detailed list of the activity factors related to production field operations, transportation, and refining is 

provided in Appendix D to this chapter (see Table D-1). 

IPCC recognizes that this level of detailed information is not readily available in every country and 

therefore offers guidance on more aggregate activity factors that can be used to quantify the size of a 

country’s oil system. Generally, aggregate activity factors such as production and consumption of oil are 

used. 

Historical Activity Data 

Oil production and consumption rates depend on economic conditions, global demand, and available 

reserves. For the purposes of this report, historical activity data were taken from publicly available 

reports, either from national communications or, when information was unavailable, from expert 

judgment (USEIA, 2005a). Table 3-1 reports oil production for selected countries in MMbbl per day for 

1990 to 2003. 

Projected Activity Data 

Oil production is projected to increase by approximately 43 percent during the next 20 years. 

Table 3-2 and Table 3-3 list forecasted estimates for oil production and consumption between 2002 and 

2025. In addition to OPEC countries continuing to expand production, Eastern European and some 

developing countries are forecasted to experience large proportional growth. Countries from the FSU in 

the Caspian Area are expected to experience the largest increase in production between 2002 and 2025, 

expanding from 1.66 to 6.22 MMbbl per day. Developing countries in regions such as Africa and the 

Middle East are also expected to expand production by 127 percent and 46 percent, respectively. 

II.3.2.2 Emissions Factors and Related Assumptions 

Emissions factors from oil production are defined as CH4 emissions rates by either equipment type or 

operation. Equipment used in crude oil production includes wellheads, compressors, pipelines, storage 

tanks, and pneumatic devices. The United States has conducted a detailed bottom-up analysis to estimate 

average emissions factors by equipment or operation type. For countries or regions where this level of 

detail is unavailable, the IPCC’s 1996 Revised Guidelines Reference Manuel provides suggested approximate 

average emissions factors for each segment of oil systems for various regions around the world. 
SECTION II — ENERGY • OIL 

II-34 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

Table 3-1: Oil Production by Country: 1990–2003 (MMbbl per Day) 

Country 1990 1995 2000 2002 2003 

Saudi Arabia 7.0 9.2 9.5 8.8 10.1 

United States 9.0 8.6 8.1 8.0 7.8 

Russian Federation N/A 6.2 6.7 7.7 8.5 

Iran 3.1 3.7 3.8 3.5 3.8 

Venezuela 2.3 3.0 3.4 2.9 2.6 

Mexico 3.0 3.1 3.4 3.6 3.8 

China 2.8 3.0 3.2 3.4 3.4 

Norway 1.8 2.9 3.3 3.3 3.3 

Canada 2.0 2.4 2.7 2.9 3.0 

Iraq 2.1 0.6 2.6 2.0 1.3 

United Arab Emirates 2.3 2.4 2.6 2.4 2.7 

United Kingdom 1.9 2.8 2.5 2.5 2.3 

Kuwait 1.2 2.2 2.2 2.0 2.3 

Nigeria 1.8 2.0 2.2 2.1 2.2 

Brazil 0.8 0.9 1.5 1.7 1.8 

World Total 65.5 68.9 75.9 75.0 77.7

Source: USEIA, 2005a. Adapted from Table G-1 in the International Energy Annual 2003.

Historical Emissions Factors 

Historical emissions factors have remained relatively constant. Countries use the IPCC’s emissions 

factors cited in the 1996 Revised Guidelines to estimate annual emissions baselines each year from 

publication of the Guidelines to the present. Table 3-4 lists aggregate emissions factors provided by the 

IPCC for petroleum system production, transportation, and refinement. These emissions factors are based 

on top-down estimates of emissions by industry segment. However, as mentioned earlier, the detailed 

bottom-up approach taken by the United States may enable a more accurate estimate of baseline 

emissions by country. The U.S. oil industry emissions factors (see Tables D-1, D-2, and D-3) are also 

assumed to remain constant in the short term (USEPA, 2004). 

IPCC and the United States report higher emissions factors in the production segment than in any 

other segment of a petroleum system (IPCC, 1996; USEPA, 2004). In the United States, pneumatic devices 

used in production field operations, flares, chemical injection pumps, and offshore platforms have the 

highest emissions factors of any type of equipment or operation in the petroleum system. 

Projected Emissions Factors 

Projected emissions factors from oil are expected to follow historical trends. IPCC and the USEPA 

predict only slight changes in their estimated emissions factors for the next 20 years.1

 Although new 

technology for equipment and operating procedures may improve in the future, current emissions factors 

for equipment and operations will increase slightly because of equipment age and usage. 

 

1 Emissions estimates do not necessarily reflect the IPCC emissions factors presented in Table 3-2. 
SECTION II — ENERGY • OIL 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES II-35

Table 3-2: Forecasted Oil Production for Selected Countries (MMbbl per Day, Unless Otherwise Noted) 

Production 2002 2010 2015 2020 2025 

Conventionala

Industrialized Countries 

United States 9.3 9.9 9.7 9.5 9.3 

Canada 2.1 1.8 1.7 1.6 1.6 

Mexico 3.6 4.3 4.6 4.7 4.9 

Western Europeb 6.9 6.4 6.0 5.6 5.0 

Japan 0.2 0.1 0.1 0.1 0.1 

Australia and New Zealand 0.8 1.0 0.9 0.9 0.9 

Total industrialized 22.9 23.5 23 22.4 21.8 

Transitional Economies 

FSU 11.2 13.6 15.3 16.4 17.5 

Russian Federation 9.6 10.3 10.8 11.1 11.3 

Caspian and otherc 1.6 3.3 4.5 5.3 6.2 

Eastern Europed 0.2 0.3 0.4 0.4 0.5 

Total transitional economies 11.4 13.9 15.7 16.8 18.0 

Emerging Economies 

OPECe

Asia 1.4 1.6 1.5 1.5 1.5 

Middle East 19.0 25.8 27.9 32.1 36.7 

North Africa 3.0 3.6 3.9 4.4 4.6 

West Africa 2.0 2.5 2.7 3.1 3.6 

South America 2.9 3.5 4.0 4.4 5.0 

Non-OPEC 

China 3.0 3.7 3.6 3.6 3.5 

Other Asia 2.4 2.7 2.8 2.8 2.7 

Middle Eastf 1.9 2.3 2.5 2.6 2.8 

Africa 2.9 3.8 4.9 5.5 6.5 

South and Central America 3.8 4.6 5.5 6.0 6.5 

Total emerging economies 42.3 54.1 59.3 66.0 73.4 

Total Production (Conventional) 76.6 91.5 98.0 105.2 113.2 

Total Production (Unconventional)g 1.5 2.8 4.9 5.5 5.7 

Total Production 78.1 94.3 102.9 110.7 118.9 

Source: USEIA, 2005b. Adapted from the International Energy Outlook 2004. Table E4. World Oil Production by Region and Country, 

Reference Case, 1990–2025. 

FSU = Former Soviet Union. 

Note: Totals may not equal sum of components because of independent rounding. Data for 2002 and 2003 are model results and may differ 

slightly from official USEIA data reports. a Includes production of crude oil (including lease condensates), natural gas, plant liquids, other hydrogen and hydrocarbons for refinery 

feedstocks, alcohol and other sources, and refinery gains. 

b Includes Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Macedonia, the Netherlands, 

Norway, Portugal, Spain, Sweden, Switzerland, and the United Kingdom. 

c Includes Armenia, Azerbaijan, Belarus, Estonia, Georgia, Kazakhstan, Krygyzstan, Latvia, Lithuania, Moldova, Tajikistan, Turkmenistan, 

Ukraine, and Uzbekistan. 

d Includes Albania, Bosnia and Herzegovina, Bulgaria, Croatia, Czech Republic, Hungary, Macedonia, Poland, Romania, Serbia Montenegro, 

Slovakia, and Slovenia. 

e OPEC = Organization of Petroleum Exporting Countries. Includes Algeria, Indonesia, Iran, Iraq, Kuwait, Libya, Nigeria, Qatar, Saudi Arabia, 

the United Arab Emirates, and Venezuela. 

f

 Non-OPEC Middle East includes Bahrain, Cyprus, Israel, Jordan, Lebanon, Oman, Syria, Turkey, and Yemen. 

g Includes liquids produced from energy crops, natural gas, coal, oil sands, and shale. Includes both OPEC and non-OPEC producers in the 

regional breakdown. 
SECTION II — ENERGY • OIL 

II-36 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

Table 3-3: Forecasted Oil Consumption for Selected Countries (MMbbl per Day, Unless Otherwise Noted) 

Consumption 2002 2010 2015 2020 2025 

Mature Market Economies 

United States 19.7 22.5 24.2 25.8 27.3 

Canada 2.1 2.3 2.5 2.5 2.6 

Mexico 2.0 2.3 2.5 2.8 3.0 

Western Europe 13.8 14.1 14.3 14.4 14.9 

Japan 5.3 5.3 5.4 5.4 5.3 

Australia/New Zealand 1.0 1.2 1.3 1.4 1.5 

Total mature market economies 43.9 47.7 50.1 52.2 54.6 

Transitional Economies 

FSU 4.1 4.7 4.9 5.2 5.5 

Eastern Europe 1.4 1.6 1.8 1.9 2.1 

Total transitional economies 5.5 6.3 6.7 7.2 7.6 

Emerging Economies 

China 5.2 9.2 10.7 12.3 14.2 

India 2.2 3.1 3.7 4.2 4.9 

South Korea 2.2 2.6 2.8 2.9 2.9 

Other Asia 5.6 7.9 9.2 10.4 11.6 

Middle East 5.7 7.3 8.0 8.6 9.2 

Africa 2.7 3.7 4.3 4.6 4.9 

South and Central America 5.2 6.8 7.8 8.5 9.3 

Total emerging economies 28.7 40.6 46.3 51.6 57.0 

Total Consumption 78.2 94.6 103.2 111.0 119.2 

Source: USEIA, 2005b. Adapted from the International Energy Outlook 2004. Table A4. World Oil Consumption by Region, Reference Case, 

1990–2025. 

FSU = Former Soviet Union. 

Note: Totals may not equal sum of components because of independent rounding. Data for 2002 and 2003 are model results and may differ 

slightly from official USEIA data reports. 

Table 3-4: IPCC Emissions Factors for Petroleum Systems in Select Regions 

Petroleum System Industry Segments (kg/petajoule) 

Production 

Region 

Fugitive 

Emissions 

Venting and 

Flaring Transportation Storage Refining 

Western Europe 300–5,000 1,000–3,000 745 90–1,400 20–250 

United States and Canadaa 300–5,000 3,000–14,000a 745 90–1,400 20–250 

FSU, Central and Eastern Europe 300–5,000 — 745 90–1,400 20–250 

Other oil-exporting countries 300–5,000 — 745 90–1,400 20–250 

Rest of the world 300–5,000 — 745 90–1,400 20–250 

Source: IPCC, 1996. Adapted from Table 1-58 in 1996 Revised Guidelines Reference Manual. 

FSU = Former Soviet Union. 

a In the United States and Canada, venting and flaring emissions are based on total production of both oil and gas produced. 
SECTION II — ENERGY • OIL 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES II-37

II.3.2.3 Emissions Estimates and Related Assumptions 

This section discusses the historical and projected baseline emissions from oil production. 

Historical Emissions Estimates 

Table 3-5 lists CH4 emissions by country from 1990 through 2000. Historically, a country’s emissions 

in the oil sector have correlated closely with oil production trends. Throughout the last decade, Mexico’s 

oil emissions have grown to be the largest of any country. By 2000, Mexico had surpassed Romania, 

which experienced a sharp decline in baseline emissions over the same time period from 1990 through 

2000. 

Projected Emissions Estimates 

As shown in Table 3-6, worldwide CH4 emissions from oil are expected to increase by more than 

80 percent from 2005 to 2020. Countries projected to experience increased production are also projected to 

have the largest growth in baseline emissions. Mexico and Brazil are projected to experience the largest 

increases at 160 percent and 157 percent, respectively, in their baseline emissions between 2005 and 2020. 

II.3.3 The Cost of CH4 Emissions Reductions from Oil 

This section discusses opportunities for emissions reductions beyond existing baseline practices. 

II.3.3.1 Abatement Option Opportunities 

Three abatement options can be applied to the oil sector: flaring, direct use, and reinjection of gas into 

oil fields for enhanced oil recovery. Table 3-7 summarizes the costs and emissions reductions associated 

with each option. 

Flaring in Place of Venting: Offshore and Onshore 

The installation of a flaring system results in an estimated 98 percent reduction in fugitive emissions. 

Implementation of a flare in an offshore environment is more expensive because of technical, 

environmental, and safety concerns. For offshore application, total capital costs are estimated to be 

approximately $818 per tCO2eq, and O&M costs are estimated to be approximately $25 per tCO2eq. This 

abatement option has a technical lifetime of 15 years, yielding a breakeven price of approximately 

$177per tCO2eq. For onshore sites, total capital costs are $34 per tCO2eq, and annual O&M costs are 

approximately $1.10 per tCO2eq, yielding a breakeven price of $7 per tCO2eq. Capital costs are assumed 

to be constant across countries, but O&M costs vary because of differences in labor costs across countries. 

This option has no monetary benefits because the CH4 is combusted and vented as CO2 to the 

atmosphere. 

Direct Use of CH4

This abatement option applies primarily to offshore platforms and has an estimated reduction 

efficiency of 90 percent. In this abatement option, CH4 is used for consumption on oil platforms and/or 

converted to liquefied natural gas. A 15-year lifetime is estimated for this abatement option. Total capital 

costs for this abatement option are approximately $55 per tCO2eq. In the United States, O&M costs are 

estimated at $1.10 per tCO2eq (O&M cost varies by country). Benefits for this abatement option are the 

cost savings from substituting CH4 for alternative energy sources. For the United States, the breakeven 

price for direct use of CH4 is $7 per tCO2eq. 
SECTION II — ENERGY • OIL 

II-38 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

Table 3-5: Baseline Emissions from Oil Production, by Country: 1990–2000 (MtCO2eq) 

Country 1990 1995 2000 

Mexico 18.8 19.3 23.3 

Romania 20.1 11.4 8.3 

China 1.2 1.4 2.2 

United States 4.4 4.1 3.9 

Nigeria 0.9 1.0 1.8 

Iran 1.3 1.6 1.2 

Kuwait 0.4 0.8 1.0 

United Arab Emirates 1.1 1.2 1.2 

Indonesia 1.2 1.0 1.9 

Iraq 1.1 0.3 0.9 

Ecuador 0.3 0.3 0.5 

Canada 0.8 0.8 0.9 

Bulgaria 0.6 0.7 0.6 

Russian Federation 1.7 0.9 0.6 

Lithuania 0.5 0.5 0.4 

Rest of the world 8.2 8.2 8.7 

World Total 62.6 53.5 57.4 

Source: USEPA, 2006. 

Table 3-6: Projected Baseline Emissions from Oil Production by Country: 2005–2020 (MtCO2eq) 

Country 2005 2010 2015 2020 

Mexico 27.7 38.7 54.1 71.9 

Romania 9.3 12.0 14.7 17.3 

China 2.9 4.4 6.1 6.5 

United States 3.4 3.7 4.1 4.5 

Nigeria 2.2 2.7 3.3 4.1 

Iran 1.8 2.2 2.7 3.6 

Kuwait 1.0 1.3 1.4 1.8 

United Arab Emirates 1.2 1.2 1.4 1.7 

Indonesia 1.9 1.8 1.6 1.4 

Iraq 0.8 0.9 1.0 1.3 

Ecuador 0.6 0.6 0.8 1.1 

Canada 0.9 0.9 1.0 1.0 

Bulgaria 0.7 0.8 0.9 1.0 

Russian Federation 0.7 0.8 0.9 1.0 

Lithuania 0.6 0.6 0.7 0.8 

Rest of the world 9.1 10.1 11.4 12.9 

World Total 64.7 82.9 106.1 131.8 

Source: USEPA, 2006. 
SECTION II — ENERGY • OIL 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES II-39

Table 3-7: Cost of Reducing CH4 Emissions from Oil 

Abatement 

Technology Year 

Capital 

Cost 

($/tCO2eq) 

Annual 

Cost 

($/tCO2eq) 

U.S. Emissions 

Available for 

Reduction 

(MtCO2eq)a

Reduction 

Efficiency 

U.S. Emissions 

Reductions 

(MtCO2eq) 

Breakeven 

Price 

($/tCO2eq)b

Flaring: offshore 

2010 832.60 24.91 0.52 98% 0.51 $170.35 

2020 832.60 24.91 0.53 98% 0.52 $170.35 

Flaring: onshore 

2010 33.30 0.99 0.52 98% 0.51 $6.82 

2020 33.30 0.99 0.53 98% 0.52 $6.82 

Direct use (offshore) 

2010 55.51 1.11 0.52 90% 0.47 $7.09 

2020 55.51 1.11 0.53 90% 0.48 $7.09 

Reinjection (onshore) 

2010 66.61 2.21 0.52 95% 0.49 $10.14 

2020 66.61 2.21 0.53 95% 0.50 $10.14 

a Based on 50 percent of CH4 emissions generated onshore and 50 percent offshore (USEPA, 2003). 

b Based on 15-year lifetime. 

Reinjection of CH4

Reinjection of CH4 is an alternative to flaring or direct use. In this option, CH4 captured from oil field 

operations is reinjected into the oil production field to enhance future oil recovery. Reinjection has an 

estimated reduction efficiency of 95 percent and a technical lifetime of 15 years. Total capital costs for this 

technology are approximately $67 per tCO2eq. Annual O&M costs are estimated to be $2.20 per tCO2eq in 

the United States, but vary by country. Benefits associated with this option include an additional increase 

in oil recovery and the mitigation of costs associated with flaring. The estimated breakeven price for the 

United States is $10 per tCO2eq. 

II.3.4 Results 

This section presents the EMF-21 study’s MAC results in tabular format and provides a graph of the 

MACs for regions with the largest emissions. 

II.3.4.1 Data Tables and Graphs 

Percentages reported in Table 3-8 are from the report to the EMF provided by the USEPA (USEPA, 

2003). It is estimated that there are no “no-regret” options for CH4 abatement in the oil sector. 

At a breakeven price of $23 per tCO2eq, the average percentage abatement is 17 percent for the 

United States and 38 percent for China, reflecting the high cost of offshore options. Technology changes 

have not been incorporated into abatement potential for CH4 from the oil sector. 
SECTION II — ENERGY • OIL 

II-40 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

Table 3-8: Percentage Abatement for CH4 for Selected Breakeven Price ($/tCO2eq): 2000 

Technology 

Breakeven 

Cost 

($/tCO2eq) 

Emissions 

Reduction (% 

from Baseline) 

Emissions 

Reduction in 2010 

(MtCO2eq) 

Emissions 

Reduction in 2020 

(MtCO2eq) 

Assuming a 10% discount rate and 40% tax rate 

Flaring instead of venting (offshore) $575.81 6% 0.02 0.03 

Flaring instead of venting (onshore) $23.03 3% 0.01 0.01 

Direct use $22.22 13% 0.05 0.06 

Reinjection $31.22 8% 0.03 0.04 

Source: USEPA, 2003. Adapted from Oil Sector technology tables in Appendix B to EMF report. 

The EMF regional baselines and MAC results of the EMF-21 study are presented in Tables 3-9 and 

3-10 for 2010 and 2020 using the base energy price, a 10 percent discount rate, and a 40 percent tax rate. 

These MACs represent static percentage reductions in baselines for individual regions/countries and 

represent the official MACs used in climate change modeling. Figure 3-2 provides MACs for the five EMF 

countries/regions with the largest estimated emissions from the oil sector in 2020. 

Table 3-9: Baseline Emissions by EMF Regional Grouping: 2000–2020 (MtCO2eq) 

Country/Region 2000 2010 2020 

Africa 3.4 4.7 7.4 

Annex I 17.6 21.9 28.8 

Australia/New Zealand 0.1 0.2 0.3 

Brazil 0.3 0.3 0.5 

China 2.2 4.4 6.5 

Eastern Europe 10.0 14.1 19.7 

EU-15 1.0 1.0 1.1 

India 0.2 0.3 0.4 

Japan 0.0 0.0 0.0 

Mexico 23.3 38.7 71.9 

Non-OECD Annex I 10.9 15.3 21.1 

OECD 30.1 45.5 79.8 

Russian Federation 0.6 0.8 1.0 

South & SE Asia 2.5 2.5 2.3 

United States 3.9 3.7 4.5 

World Total 57.4 82.9 131.8 

Source: USEPA, 2006. 

EU-15 = European Union; OECD = Organisation for Economic Co-operation and Development. 

Note: World Total does not equal the sum of the countries listed in this table because the regional groupings are a subset of the full EMF 

regional grouping list. See Appendix A of this report for the full EMF list of countries by region. 
SECTION II — ENERGY • OIL 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES II-41

Table 3-10: Oil System MACs for Countries Included in the Analysis 

Percentage Reduction from Baseline (tCO2eq) 

2010 2020 

Country/Region $0 $15 $30 $45 $60 $0 $15 $30 $45 $60 

Africa 0.00% 37.27% 37.27% 37.27% 46.05% 0.00% 37.27% 37.27% 37.27% 46.05% 

Annex I 0.00% 21.48% 21.48% 21.48% 26.54% 0.00% 20.16% 20.16% 20.16% 24.91%

Australia/New Zealand 0.00% 22.07% 22.07% 22.07% 27.26% 0.00% 22.07% 22.07% 22.07% 27.26% 

Brazil 0.00% 26.69% 26.69% 26.69% 32.97% 0.00% 26.69% 26.69% 26.69% 32.97% 

China 0.00% 38.17% 38.17% 38.17% 47.15% 0.00% 38.17% 38.17% 38.17% 47.15% 

Eastern Europe 0.00% 13.12% 13.12% 13.12% 16.20% 0.00% 13.12% 13.12% 13.12% 16.20% 

EU-15 0.00% 11.71% 11.71% 11.71% 14.47% 0.00% 11.71% 11.71% 11.71% 14.47% 

India 0.00% 17.54% 17.54% 17.54% 21.66% 0.00% 17.54% 17.54% 17.54% 21.66% 

Japan 0.12% 0.22% 0.22% 0.22% 0.27% 0.12% 0.22% 0.22% 0.22% 0.27% 

Mexico 0.00% 34.64% 34.64% 34.64% 42.79% 0.00% 34.64% 34.64% 34.64% 42.79% 

Non-OECD Annex I 0.00% 31.67% 31.67% 31.67% 39.12% 0.00% 30.81% 30.81% 30.81% 38.06%

OECD 0.00% 24.55% 24.55% 24.55% 30.33% 0.00% 22.75% 22.75% 22.75% 28.11%

Russian Federation 0.00% 33.98% 33.98% 33.98% 41.97% 0.00% 33.98% 33.98% 33.98% 41.97% 

South & SE Asia 0.00% 24.07% 24.07% 24.07% 29.73% 0.00% 24.07% 24.07% 24.07% 29.73% 

United States 0.00% 17.67% 17.67% 17.67% 21.83% 0.00% 17.67% 17.67% 17.67% 21.83% 

World Total 0.00% 28.08% 28.08% 28.08% 34.69% 0.00% 28.96% 28.96% 28.96% 35.78% 

Source: USEPA, 2003. 

EU-15 = European Union; OECD = Organisation for Economic Co-operation and Development. 

Figure 3-2: EMF MACs for Top Five Emitting Countries/Regions from Oil: 2020 

Source: USEPA, 2003. 

Note: Regional MACs were constructed using percentage reductions from USEPA (2003), with baselines from USEPA (2005). 

-$10

$0

$10

$20

$30

$40

$50

0 5 10 15 20 25 30 35

Absolute Reduction (MtCO2eq)

$/tCO2eq

China

Africa

Eastern Europe

Mexico

United States
SECTION II — ENERGY • OIL 

II-42 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

II.3.5 Uncertainties and Limitations 

Uncertainties and limitations persist despite attempts to incorporate all publicly available 

international oil sector information. Limited information on the oil systems of developing countries 

increases this uncertainty. Additional information would improve the accuracy of baseline emissions 

projections: 

• Improved Cost Data. Improved documentation of oil CH4 abatement options and their cost 

components would make it easier to estimate baseline reductions, given some estimate of market 

penetration. 

• Improved Emissions Factor Data. Improved documentation of emissions factors for oil systems 

of countries outside the United States would enhance the accuracy of international analysis of 

CH4 emissions. 

• Improved Abatement Option Data. Improved abatement option data are needed to identify true 

abatement opportunities for oil systems. For example, although flares have long been thought of 

as a potential abatement option, new research suggests that some amount of CH4 may be 

escaping combustion at the site of the flare. Accurate information on emissions factors is 

necessary before reduction efficiencies can be estimated. 

II.3.6 Summary 

The data discussed in this chapter demonstrate that oil is a significant source of greenhouse gas 

emissions, but because of information limitations for some countries, a more thorough cost analysis is not 

possible. Self-regulation by industry and changes in market structure may lead to reductions in emissions 

baselines in the future. However, to truly understand the potential benefits of an abatement option in an 

oil system and to estimate potential market penetration across countries, more information is needed. 

II.3.7 References 

Intergovernmental Panel on Climate Change (IPCC). 1996. Revised 1996 IPCC Guidelines for National 

Greenhouse Gas Inventories: Reference Manual (Volume 3). Available at <http://www.ipcc-nggip. 

iges.or.jp/public/gl/invs6.htm>. As obtained on April 26, 2004. 

U.S. Department of Energy (USDOE), U.S. Energy Information Administration (USEIA). 2005a. 

International Energy Annual 2003. Washington, DC: USEIA. Available at <http://www.eia.doe.gov/ 

iea/>. As obtained on May 3, 2006. 

U.S. Department of Energy (USDOE), U.S. Energy Information Administration (USEIA). 2005b. 

International Energy Outlook 2005. Washington, DC: USEIA. Report # DOE/EIA-0484. Available at 

<http://www.eia.doe.gov/oiaf/ieo/>. As obtained on March 3, 2006. 

U.S. Environmental Protection Agency (USEPA). 2003. International Analysis of Methane and Nitrous Oxide 

Abatement Opportunities: Report to Energy Modeling Forum, Working Group 21. Appendices. Washington, 

DC: USEPA. Available at <http://www.epa.gov/methane/intlanalyses.html>. As obtained on 

September 27, 2004. 

U.S. Environmental Protection Agency (USEPA). 2004. Inventory of U.S. Greenhouse Gas Emissions and Sinks 

1990–2002. Washington, DC: USEPA, Office of Solid Waste and Emergency Response. Available at 

<http://www.epa.gov/methane/intlanalyses.html>. As obtained on October 17, 2004. 

U.S. Environmental Protection Agency (USEPA). 2006. Global Anthropogenic Non-CO2 Greenhouse Gas 

Emissions: 1990–2020. Washington, DC: USEPA. 
Section II: Energy Sector Appendixes 

Appendixes for this section are available for download from the USEPA’s Web site at 

http://www.epa.gov/nonco2/econ-inv/international.html. 

III. Waste 
SECTION III — WASTE • PREFACE 

III-ii GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

Section III presents international emissions baselines and marginal abatement curves (MACs) for waste 

sources. There are two chapters, one addressing individual sources from the landfill sector and one 

addressing sources from the wastewater sector. These sources include emissions of methane (CH4) and 

nitrous oxide (N2O). MAC data are presented in both percentage reduction and absolute reduction terms 

relative to the baseline emissions. These data can be downloaded in spreadsheet format from the 

USEPA’s Web site at <http://www.epa.gov/nonco2/econ-inv/international.html>. 

Section III—Waste chapters are organized as follows: 

Methane (CH4) 

III.1 Landfill Sector 

Methane (CH4) and Nitrous Oxide (N2O) 

III.2 Wastewater Sector 
SECTION III — WASTE • LANDFILL 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES III-1 

III.1 Landfill Sector 

orldwide methane (CH4) from the landfilling of municipal solid waste (MSW) accounted 

for over 730 million metric tons of carbon dioxide (MtCO2eq) equivalent in 2000 and 

represented over 12 percent of total global CH4 emissions. The United States, Africa, 

Eastern Europe, and China combined account for 42 percent of the world’s CH4 emissions from landfills 

(see Figure 1-1). Global CH4 emissions from landfills are expected to grow by 9 percent between 2005 and 

2020. Most developed countries have regulations that will constrain and potentially reduce future growth 

in CH4 emissions from landfills. However, areas of the world such as Eastern Europe and China are 

projected to experience steady growth in landfill CH4 emissions because of improved waste management 

practices diverting more MSW into managed landfills. 

Figure 1-1: CH4 Emissions from Municipal Solid Waste by Country: 2000–2020 

Source: Environmental Protection Agency (USEPA), 2006. 

III.1.1 Introduction 

CH4 from landfills is produced in combination with other landfill gases (LFGs) through the natural 

process of bacterial decomposition of organic waste under anaerobic conditions. The CH4 along with 

other LFGs is generated over a period of several decades (usually beginning 1 to 2 years after the waste is 

put in place). CH4 makes up approximately 50 percent of LFG, with the remaining 50 percent being CO2

mixed with small quantities of other gases. If landfill CH4 is not collected, it will escape to the 

atmosphere. 

The production of landfill CH4 gas depends on several key characteristics, including waste 

composition, landfill design, and operating practices, as well as local climate conditions. Two factors that 

will accelerate the rate of CH4 generation within a landfill are an increased share of organic waste (paper, 

food scraps, brush) in the mix of MSW being landfilled and increased levels of moisture in the waste. In 

addition, if the landfill has used a soil cover (daily cover, intermediate cover, or final cover) in its 

W 

0

100

200

300

400

500

600

700

800

900

1,000

2000 2010 2020

Year

MtCO2eq

China

Eastern Europe

Africa

United States

Rest of the world
SECTION III — WASTE • LANDFILL 

III-2 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

operations, a portion of the CH4 will be oxidized as it passes through these soil layers and converted to 

CO2. Many landfill management practices are regulated to control for health and environmental concerns. 

The U.S. federal government currently requires all landfills to monitor and control landfill gas 

migration and requires larger landfills to collect and combust landfill gas to destroy the non-CH4 organic 

compounds. Landfills with a design capacity greater than 2.5 million megagrams (or 2.8 million short 

tons) are subject to the New Source Performance Standards and Guidelines (NSPS/EG) of the Clean Air 

Act (USEPA, 1999a), referred to in this chapter as the “Landfill Rule.” Similar regulations exist in the 

European Union (EU-15) and other developed countries to control the CH4 emissions from large landfills. 

However, in most developing countries, there are no regulations covering landfill CH4 emissions. Despite 

efforts to control large landfill emissions, the landfill sector remains a significant source of CH4 emissions. 

Abatement options include the capture of CH4 for flaring or energy production and enhanced waste 

management practices to reduce waste disposal at landfills (such as recycling-and-reuse programs). CH4

recovery for energy use is another approach and is the focus of this report’s marginal abatement curve 

(MAC) analysis. Because of its low cost, flaring is the most commonly adopted abatement option; 

however, this report also considers two energy recovery options as viable alternatives to flaring that may 

provide greater financial incentive to landfill managers. 

The following sections discuss the activity data and emissions factors used to develop baseline 

emissions, abatement options and their costs, and CH4 MACs for the landfill sector. The chapter 

concludes with a discussion of uncertainties and limitations. As an appendix to this analysis, we discuss 

recent efforts to improve on the MAC methodology by incorporating technology change and by building 

the MACs from a population of individual landfills. 

III.1.2 Baseline Emissions Estimates 

This section discusses the characteristics of landfills and how the characteristics affect CH4 emissions. 

In this section, we also describe historical and projected trends that influence baseline emissions from 

MSW landfills. In general, the quantity of CH4 generated is determined by four main factors: 

• population 

• quantity of waste disposed of per capita 

• composition of waste disposed of 

• type of waste disposal site (landfill versus open dump) 

It is commonly accepted that waste generation grows approximately proportional to a country’s 

population. In addition, countries with higher gross domestic product (GDP) per capita typically generate 

more waste per capita. The amount of waste generated per capita multiplied by the population 

determines the amount of MSW available for disposal. 

The composition of waste, which influences CH4 emissions rates, varies across countries. The level of 

recycling or reuse of plastics, metals, organics, and other inorganic waste affects both the amount of 

waste disposed of and the type of waste available to generate CH4. Generally, formal recycling-and-reuse 

programs are incremental improvements employed by countries that already have sanitary landfills in 

place. However, open dumps often have high levels of recovery of both organic and inorganic materials 

from informal programs involving human activities and animal scavenging. 

The type of waste disposal site also significantly influences CH4 generation. There are generally three 

types of waste disposal sites⎯open dumps, controlled or managed dumps, and sanitary landfills. Open 

dumps are characterized by open fills with loosely compacted waste layers. Managed dumps are similar 
SECTION III — WASTE • LANDFILL 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES III-3 

to open dumps but are better organized and may have some level of controls in place. Open and 

controlled dumps are not conducive to CH4 generation primarily because of aerobic conditions as well as 

other factors such as shallow layers and unconsolidated disposal (i.e., waste disposed in different parts of 

the same landfill site on different days). Sanitary landfills are sites designed and operated to accept MSW 

and employ waste management practices, such as mechanical waste compacting and the use of liners, 

daily cover, and a final cap (Intergovernmental Panel on Climate Change [IPCC], 1996). Developed 

countries primarily employ sanitary landfills. In developing countries, there is a mix of open dumps (in 

rural and some urban sites), managed dumps (mainly in larger townships), and sanitary landfills (in large 

cities). 

III.1.2.1 Activity Data 

This section discusses the historical and projected activity factors that determine CH4 generation at 

solid waste disposal sites and policies set to improve waste management practices. 

Historic Activity Data 

Industrialized countries traditionally have the highest per capita waste generation rates and have 

accounted for the dominant share of global MSW production each year. Industrialized countries have 

also been the first to adopt sanitary landfills, employing waste compaction, dirt covers, and final caps. 

Sanitary landfills enable more waste to decay in an anaerobic environment, which ultimately leads to an 

increase in CH4 production. However, industrialized countries have also led the way in adopting landfill 

gas (LFG) regulations and LFG utilization projects. 

Developing countries historically have high population growth rates but use open dumps for waste 

disposal because of decentralized waste management programs and cost factors. Open dump waste 

disposal sites often do not provide the anaerobic conditions necessary to produce large quantities of CH4. 

Some developing countries may have managed dumps that could create the anaerobic conditions 

required to generate CH4 emissions. When calculating a country’s baseline emissions, it is important to 

determine whether the country has any managed dumps. Additionally, economic growth in developing 

countries may result in an increased migration from rural communities to larger urban settings. Larger 

amounts of waste landfilled in the sanitary and managed dumps in these larger urban cities may 

potentially increase the amount of CH4 generated. 

Projected Activity Data 

Globally, projections indicate that the amount of MSW being deposited into sanitary landfills is 

expected to grow. Developing countries are expected to move away from open dumps toward more 

sanitary landfills. The fraction of waste disposed of in landfills versus open dumps is expected to increase 

at the rate of per capita GDP growth. 

Industrialized countries are expected to increase the level of LFG regulation and LFG utilization 

projects. These countries will also continue to improve or implement composting, recycling, and reuse 

programs. For example, in the United States the fraction of waste generated that is landfilled has 

decreased from 72 percent of all waste generated in 1989 to 56 percent of all waste generated in 2000 

(USEPA, 2003b). 

III.1.2.2 Emissions Factors and Related Assumptions 

The emissions factors for sanitary landfills are defined as the CH4 generated per ton of waste 

accumulated and are primarily determined by, but are not limited to, four factors: the type and age of the 

waste buried in the landfill, the quantity and types of organic compounds in the waste, the moisture 
SECTION III — WASTE • LANDFILL 

III-4 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

content of the waste, and temperature of the waste. Temperature and moisture levels are influenced by 

the surrounding climate. CH4 emissions factors are significantly higher for sanitary landfills compared 

with open dumps because of the presence of anaerobic conditions. 

Historical Emissions Factors 

Industrialized countries have only recently begun adopting waste management practices such as 

recycle-and-reuse programs for organic materials. Before these programs were instituted, industrialized 

MSW had a higher organic material composition, which resulted in higher emissions factors. 

Developing countries’ emissions factors for landfills have historically been lower than industrialized 

countries because of the use of open dumps, which have shallow layers of rapidly decaying organic 

matter under aerobic conditions, preventing the accumulation of CH4. In addition, open dumps make it 

easy for both animal scavengers and human waste pickers to remove food and paper, effectively reducing 

the amount of organic waste that would otherwise decay and ultimately generate CH4. Fires are also 

common at open dump sites and can alter the composition of the MSW, reducing its ability to generate 

CH4. 

Projected Emissions Factors 

Industrialized countries’ emissions factors for landfills are projected to decrease. As these countries 

continue improving their waste management practices, more of the organic waste will be taken out of the 

MSW disposed of at landfills, thereby lowering the landfill’s CH4 generation potential. One example is 

the EU Landfill Directive, which has limited the amount of organic matter that can enter MSW facilities. 

Additionally, steady economic growth and small or negative population growth may again lower 

emissions factors for landfills in industrialized countries. 

Emissions factors for developing countries’ landfills will increase as these countries move away from 

open dumps toward sanitary landfills. Sanitary landfills typically do not allow for scavengers to reduce 

the organic composition of the MSW. This possibility, in combination with the lack of established 

recycling programs, could lead to a dramatic increase in the emissions factors for these landfills. 

III.1.2.3 Emissions Estimates and Related Assumptions 

This section discusses the historical and projected baseline landfill emissions for both industrialized 

and developing countries. Figure 1-2 summarizes the components of landfill baseline CH4 emissions, 

where incremental landfill management improvements, such as increased recycling programs, are 

accounted for through a reduction in the amount of waste accumulating at a landfill. This has a direct 

effect on the quantity of CH4 generated at MSW landfills. In countries for which no emissions estimate 

was available, the IPCC Tier 1 methodology was used to estimate baselines using IPCC default values. 

For more detailed discussion of baseline emissions calculation methodology, see the USEPA’s (2006) 

Global Emissions Inventory Report. 

Historical Emissions Estimates 

Table 1-1 lists the historical baselines for the world’s leading countries in CH4 emissions from 

landfills. The United States, by far the largest emitter of CH4 from landfills, experienced a decline in 

baseline emissions as a result of the Landfill Rule and LFG utilization. Former Soviet countries of Eastern 

Europe, such as the Ukraine and Poland, have experienced gradual increases as these newly independent 

states begin to develop their waste management programs and a larger fraction of the MSW generated is 

disposed of at managed landfills. 
SECTION III — WASTE • LANDFILL 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES III-5 

Figure 1-2: Components of CH4 Emissions from Landfills 

Total landfill CH4 emissions 

equal 

CH4 generated from MSW landfills 

minus 

CH4 recovered and flared or used for energy 

minus 

CH4 oxidized from MSW landfills 

plus 

Methane emissions from industrial waste sites 

Source: USEPA, 1999b. 

Table 1-1: CH4 Emissions from Municipal Solid Waste by Country: 1990–2000 (MtCO2eq) 

Country 1990 1995 2000 

United States 172.2 162.4 130.7 

China 40.4 42.6 44.6 

Mexico 26.0 28.5 31.0 

Canada 18.5 20.4 22.9 

Russian Federation 37.8 37.8 35.1 

Saudi Arabia 12.5 14.4 16.8 

India 10.7 12.2 13.9 

Brazil 13.0 14.5 15.6 

Ukraine 14.2 14.5 12.1 

Poland 16.1 15.9 17.0 

South Africa 14.1 15.2 16.3 

Turkey 8.2 8.9 9.7 

Israel 6.6 7.8 8.8 

Australia 7.5 8.3 8.0 

Dem. Rep. of Congo (Kinshasa) 5.0 5.9 6.4 

Rest of the world 358.7 360.4 341.6

World Total 761.4 769.7 730.3

Source: USEPA, 2006. 

Historically, in developed countries, baseline CH4 emissions from landfills are decreasing because of 

improved recovery technologies and mandated regulation to capture and control LFG (which includes 

CH4) produced at the world’s CH4-producing landfills. Many countries have instituted regulations that 

require large landfills to install CH4 capture-and-flaring systems either for safety or environmental 

concerns. For example, the United States enacted the Landfill Rule in 1996; the EU and the United 

Kingdom have enacted similar legislation to limit LFG generation or require its collection and control. 

The landfill rule requires landfill gas to be collected and combusted either through flaring or use at 

landfills that have a design capacity greater than 2.5 million metric tons (Mt) and 2.5 million cubic meters 
SECTION III — WASTE • LANDFILL 

III-6 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

(m3). This rule and similar rules in other developed countries have reduced the amount of CH4 in the 

baseline estimates for each year after 1999. 

Developing countries are increasing the fraction of waste disposed of at landfills as the amount of 

waste generated increases with per capita GDP. However, as discussed earlier, open dumps have been 

the primary method for waste disposal in developing countries, and because of the characteristics of these 

landfills, they tend not to produce large amounts of CH4. Open dumps have kept CH4 baseline emissions 

from landfills in developing countries low. However, very large open dumps and managed dumps can 

be significant sources of CH4 emissions given sufficient conditions, such as depth, the amount of waste in 

place, and the rate of waste accumulation annually. 

Projected Emissions Estimates 

Worldwide CH4 emissions from landfills are expected to decrease in industrialized countries and 

increase in developing countries. Industrialized countries’ baselines will continue to decline because of 

expanding recycling-and-reuse programs, increased LFG regulation, and improved LFG recovery 

technologies. Developing countries’ baseline landfill emissions are expected to increase because of their 

rapidly expanding populations—trending away from open dumps to sanitary landfills to improve health 

conditions—and because of a lack of formal recycling programs in the near future. Formal recycling 

programs typically follow the adoption of sanitary landfills. Table 1-2 lists the projected baseline 

emissions for the world’s top emitters over the period from 2005 to 2020 in MtCO2eq. 

Table 1-2: Projected Baseline CH4 Emissions from Municipal Solid Waste by Country: 2005–2020 (MtCO2eq) 

Country 2005 2010 2015 2020 

United States 130.6 125.4 124.1 123.5 

China 46.0 47.5 48.8 49.7 

Mexico 33.3 35.5 37.4 39.2 

Canada 25.3 27.7 30.7 33.6 

Russian Federation 34.2 33.2 32.2 31.1 

Saudi Arabia 19.4 22.1 24.8 27.5 

India 15.9 17.1 18.1 19.1 

Brazil 16.6 17.5 18.3 19.0 

Ukraine 13.4 14.7 16.4 18.0 

Poland 17.0 17.0 17.0 17.0 

South Africa 16.8 16.6 16.4 16.2 

Turkey 10.4 11.0 11.6 12.1 

Israel 9.7 10.6 11.3 11.9 

Australia 8.7 9.4 10.6 11.9 

Dem. Rep. of Congo (Kinshasa) 7.4 8.6 9.8 11.2 

Rest of the world 342.7 346.7 360.5 375.9

World Total 747.4 760.6 788.1 816.9

Source: USEPA, 2006. 
SECTION III — WASTE • LANDFILL 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES III-7 

Developing nations are projected to experience only slight declines in baseline emissions through 

government policies such as the Landfill Rule passed in the United States in 1996. As recovery techniques 

improve, the number of landfills that can profit from the LFG recovery will increase, which will continue 

to drive down the level of baseline emissions in developed as well as developing countries. 

III.1.3 Cost of Emissions Reductions from Landfills 

CH4 emissions from landfills can be reduced using two approaches: 

• capture the CH4 and flare it or use it for energy and 

• change waste management practices to reduce waste disposal at landfills by adding composting 

and recycling-and-reuse programs. 

CH4 recovery for flaring or energy is the most popular approach and is the focus of this report’s cost 

analysis. However, documented or expected changes in disposal rates due to composting and recycling 

are accounted for in the baseline emissions estimates for each country. 

III.1.3.1 Abatement Option Opportunities 

Collection systems are present in most landfills as a mechanism to prevent migration of the gas to onsite structures or away from the landfill to adjacent property and to prevent the release of non-CH4

organic compounds to the atmosphere. Following the collection of CH4, the landfill operator must make a 

decision to flare, pump the gas to an end user for process heat, or generate electricity. Table 1-3 specifies 

the components of the gas collection and flaring system and direct-use system. 

Table 1-3: Components of Collection and Flaring and LFG Utilization Abatement Options 

System Type of Equipment 

Collection and flaring Wells 

Wellheads and gathering pipeline system 

Knockout, blower, and flare 

Utilization (i.e., electricity production and direct use) Skid mounted filter 

Compressor 

Dehydrator unit 

Pipeline 

Turbine, engine, or boiler 

Source: USEPA, 2003a. 

The USEPA’s LFG cost model estimates LFG generation, one-time capital costs, annual operation and 

maintenance (O&M) fees, and the quantity of gas recoverable for flaring or utilization for individual 

landfills. An expected technology lifetime of 15 years is used. This section discusses the one-time capital 

and annual costs and the annual cost savings for the two most popular options: collection and flaring and 

utilization. For a complete list of the technology options considered by the Economic Modeling Forum 

(EMF) 21 study for the landfill sector, see Table 1-4 below. 

Collection and Flaring 

The presence of CH4 can be a public health concern, as well as a safety hazard at landfills if the 

concentration builds up. For this reason, large landfills have historically removed the CH4 and then 

combusted the gas through flaring. Gas is collected through vertical wells and a series of horizontal 
SECTION III — WASTE • LANDFILL 

III-8 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

collectors typically installed following the closing of a landfill cell. Vertical wells are the most common 

type of well, while horizontal collectors are used primarily for deeper landfills and landfill cells that are 

actively being filled. Once captured, the gas is then channeled through a series of gathering lines to a 

main collection header. The USEPA recommends that the collection system be designed so that an 

operator can monitor and adjust the gas flow. 

• Capital Costs. This abatement option requires the installation of vertical or horizontal wells; 

wellheads and gathering pipeline system; and a knockout, blower, and flare system. The 

USEPA’s cost model estimates one well for every acre of landfill at a cost of $7,200 per well. The 

gathering pipeline system’s cost is determined by the number of wells at the landfill. The USEPA 

estimates the cost for the collection system as a fixed cost of $19,000, plus a cost of $8,756 per well. 

Finally, the cost of the knockout, blower, and flare system is determined by the gas flow rate. For 

example, if a landfill produced 1,000,000 cubic feet per day, the USEPA estimates the cost to be 

approximately $200,000. 

• Annual Costs. Annual costs include labor costs associated with monitoring the gas flows, 

moving or maintaining gas collection systems, and maintaining the flare. Additionally, there is an 

annual cost associated with the electricity used by blowers. Annual costs are typically 10 percent 

of one-time capital costs. 

• Cost Savings/Benefits. Increased environmental and public health benefits, as well as increases 

in safety at the landfill site, are the primary benefits. The flaring system is an effective way of 

reducing large quantities of CH4 emissions from landfills. Additional nonmarket benefits include 

the reduction of volatile organic compounds (VOCs) and reduced odor. 

LFG Utilization Systems 

Components of a capture and utilization abatement option for the landfill sector include a landfill gas 

collection system, utilization pumping system, or some mechanism such as a turbine for generating 

energy through the combustion of landfill CH4 gas. LFG is extracted from landfills using a series of 

vertical or horizontal wells and a blower (or vacuum) system. This system directs the collected gas to a 

central point, where it can be processed and treated depending on the ultimate use of the gas. From this 

point, the gas simply can be flared or used to generate electricity, or the gas can be pumped to an enduser for process heat. Additional direct-use options, such as fuel to run leachate evaporators and liquid 

natural gas production, also reduce CH4 emissions. 

In addition, landfill CH4 gas can be transported and used in industrial processes, such as boilers, 

drying operations, kiln operations, and cement and asphalt production. Gas collected from the landfill 

can be piped directly to local industries where it is used as a replacement or supplementary fuel. The 

ideal customers will have a steady, annual energy demand that will use a large percentage or all of the 

landfill’s gas flow. 

• Capital Costs. Utilization systems may require the installation of a skid-mounted filter, 

compressor, and dehydrator unit and mile(s) of pipeline to carry gas to the customer. Costs for 

the skid-mounted filter, compressor, and dehydrator unit are based on the gas flow rate. For a 

landfill with a gas flow rate of 1 million cubic feet per day, the USEPA estimates the installed 

costs of the filter, compressor, and dehydrator to be approximately $180,000. The USEPA 

estimates the installation cost for the pipeline is $264,000 per mile. 

• Annual Costs. Annual costs are composed primarily of electricity usage by the compressor and 

dehydrator unit. Estimated annual costs for O&M and electricity are $100,000. 
SECTION III — WASTE • LANDFILL 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES III-9 

• Annual Savings/Benefits. Annual benefits are determined by the quantity of gas sold, the British 

thermal unit (Btu) content of the landfill gas, and the current market price of natural gas. Given 

the 2004 price of natural gas in the United States, annual benefits can be up to 10 times as great as 

annual costs. 

III.1.4 Results 

This section presents the EMF-21 study’s MAC results in tabular format. 

III.1.4.1 Data Tables and Graphs 

Table 1-4 presents the average breakeven price and the reduction in absolute and percentage terms 

for the mitigation options discussed in Section III.1.3.1. Table 1-5 presents the baseline emissions for 

landfills by EMF regional grouping. Table 1-6 presents the percentage reduction in the baseline emissions 

at specific breakeven prices, and Figure 1-3 provides MACs for the five EMF countries/regions with the 

largest estimated emissions from MSW landfills in 2020. 

Table 1-4: Breakeven Prices of MSW Landfill Technology Options 

Technology 

Breakeven 

Cost 

($/tCO2eq) 

Emissions 

Reduction (% 

from baseline) 

Emissions 

Reduction in 2010 

(MtCO2eq) 

Emissions 

Reduction in 2020 

(MtCO2eq) 

Assuming a 10% discount rate and a 40% tax rate 

Anaerobic digestion 1 (AD1)a $36.03 10% 0.16 0.16 

Anaerobic digestion 2 (AD2)b $428.74 10% 0.16 0.17 

Composting (C1)c $243.45 13% 0.45 0.52 

Composting (C2)d $265.41 12% 0.43 0.49 

Mechanical biological treatment $362.94 10% 0.16 0.16 

Heat production –$16.70 9% 0.31 0.36 

Increased oxidation $265.20 6% 0.21 0.24 

U.S. direct gas use (profitable at 

base price) 

$0.90 10% 0.34 0.39 

Electricity generation $73.02 10% 0.34 0.39 

Direct gas use (profitable above 

base price) 

$8.09 10% 0.34 0.39 

Flaring $24.69 10% 0.34 0.39 

Source: USEPA, 2003c. Adapted from landfill technology tables in Appendix B. 

a AD1 expedites the natural decomposition of organic material without oxygen by using a vessel that excludes oxygen and maintains the 

temperature, moisture content, and pH close to their optimum values. CH4 can be used to produce heat and/or electricity. 

b AD2 expedites the natural decomposition of organic material without oxygen by using a vessel that excludes oxygen in the same way as 

AD1, but with additional income from compost. 

c C1 involves degradation of the organic matter under aerobic conditions. It requires separating organic matter from the waste stream. 

Finished compost has a market value because it is used to enhance soil in horticulture/landscape and agricultural sites. 

d C2 involves the degradation of organic matter under aerobic conditions and the separation of organic matter from the waste stream in the 

same way as C1, but there are larger costs. 
SECTION III — WASTE • LANDFILL 

III-10 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

Table 1-5: Baseline Emissions by EMF Regional Grouping: 2000–2020 (MtCO2eq) 

Country/Region 2000 2010 2020 

Africa 84.2 101.1 118.8 

Annex I 349.6 315.7 312.4 

Australia/New Zealand 9.4 11.0 13.6 

Brazil 15.6 17.5 19.0 

China 44.6 47.5 49.7 

Eastern Europe 47.2 49.7 51.9 

EU-15 84.6 46.3 32.7 

India 13.9 17.1 19.1 

Japan 3.9 3.1 2.4 

Mexico 31.0 35.5 39.2 

Non-OECD Annex I 62.2 65.1 69.1 

OECD 328.6 297.0 293.5 

Russian Federation 35.1 33.2 31.1 

South & SE Asia 23.6 27.9 31.5 

United States 130.7 125.4 123.5 

World Total 730.3 760.6 816.9 

Source: USEPA, 2006. 

EU-15 = European Union; OECD = Organisation for Economic Co-operation and Development. 

Table 1-6: MSW Landfill MACs for Countries Included in the Analysis 

Percentage Reduction from Baseline in tCO2eq 

2010 2020 

Country/Region $0 $15 $30 $45 $60 $0 $15 $30 $45 $60 

Africa 20.71% 42.14% 52.86% 52.86% 87.31% 20.71% 42.14% 52.86% 52.86% 87.31%

Annex I 11.16% 38.89% 45.45% 63.58% 88.25% 11.54% 40.18% 46.96% 65.70% 91.19% 

Australia/New Zealand 7.00% 29.50% 46.50% 46.50% 90.12% 7.00% 29.50% 46.50% 46.50% 90.12%

Brazil 20.71% 42.14% 52.86% 52.86% 87.31% 20.71% 42.14% 52.86% 52.86% 87.31% 

China 10.00% 42.14% 52.86% 52.86% 87.31% 10.00% 42.14% 52.86% 52.86% 87.31% 

Eastern Europe 20.71% 42.14% 52.86% 52.86% 87.31% 20.71% 42.14% 52.86% 52.86% 87.31% 

EU-15 7.00% 29.50% 46.50% 46.50% 90.12% 7.00% 29.50% 46.50% 46.50% 90.12%

India 10.00% 52.86% 52.86% 52.86% 87.31% 10.00% 52.86% 52.86% 52.86% 87.31%

Japan 31.50% 66.00% 66.00% 66.00% 90.12% 31.50% 66.00% 66.00% 66.00% 90.12%

Mexico 10.00% 42.14% 52.86% 52.86% 87.31% 10.00% 42.14% 52.86% 52.86% 87.31%

Non-OECD Annex I 10.00% 42.14% 52.86% 52.86% 87.31% 9.20% 38.76% 48.61% 48.61% 80.30% 

OECD 11.42% 38.42% 44.53% 64.55% 88.37% 11.91% 40.05% 46.43% 67.31% 92.14% 

Russian Federation 10.00% 42.14% 52.86% 52.86% 87.31% 10.00% 42.14% 52.86% 52.86% 87.31%

South & SE Asia 10.00% 42.14% 52.86% 52.86% 87.31% 10.00% 42.14% 52.86% 52.86% 87.31%

United States 10.00% 42.14% 42.14% 80.71% 87.31% 10.00% 42.14% 42.14% 80.71% 87.31%

World Total 11.71% 40.54% 48.95% 58.35% 87.81% 11.82% 40.68% 49.62% 56.84% 87.76% 

Source: USEPA, 2003c. 

EU-15 = European Union; OECD = Organisation for Economic Co-operation and Development. 
SECTION III — WASTE • LANDFILL 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES III-11 

Figure 1-3: EMF MACs for Top Five Emitting Countries/Regions from Landfills: 2020 

The MACs presented in this section represent static abatement curves using breakeven prices built on 

the assumption of fixed mitigation cost, and aggregate countrywide landfill statistics. Appendix E 

presents more recent efforts to develop an alternative framework for conducting MAC analysis that 

addresses the limitations of the EMF-21 MAC analysis for the landfill sector.

III.1.4.2 Uncertainties and Limitations 

Uncertainty and limitations persist despite attempts to incorporate all publicly available information 

on international landfill sectors. Additional information would improve the accuracy of the MACs’ 

projections. 

• Landfill Populations. A major source of uncertainty in the MACs is due to a lack of reliable 

information on the landfill population for all countries. Improved information on waste 

acceptance rates, waste composition, trends in waste management practices, and landfill capacity 

data by landfill for each country would greatly improve the analyst’s ability to calculate benefits 

and hence breakeven prices. 

• Climate Change. The presence of moisture plays a large role in determining the CH4 generation 

rate for landfills in each country. Improved projected and historical data on the weather 

conditions at future and existing landfills would contribute to improving the accuracy of our 

estimations of CH4 generation. This would also contribute to the heterogeneity of each country’s 

MAC and of the landfills within each country. 

• Country-Specific Waste Management Practices. Improved documentation of waste management 

practices would allow deviations from the normal assumption that waste generation increases 

along with population. Instituting recycling-and-reuse programs reduces the fraction of waste 

deposited in the landfills. 

-$10

$0

$10

$20

$30

$40

$50

0 20 40 60 80 100 120 140 160

Absolute Reduction (MtCO2eq)

$/tCO2eq

China

Africa

Eastern Europe

United States

Russian Federation
SECTION III — WASTE • LANDFILL 

III-12 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

• Adjusting Costs for Specific Domestic Situations. Currently, the technologies considered in this 

report are available in the United States, Canada, and Western Europe for the costs reported. 

However, countries other than these countries may be faced with higher costs because of 

transportation and tariffs associated with purchasing the technology from abroad or could be 

faced with lower costs due to domestic production of these technologies. Data on domestically 

produced technologies, both costs and reduction efficiencies, are not available. 

• Country-Specific Tax and Discount Rates. A single tax rate is applied to landfills and landfills in 

all countries to calculate the annual benefits of each technology. Tax rates can vary across 

countries and in the case of state-run mines and landfills in China, taxes may be less applicable. 

Similarly the discount rate may vary by country. Improving the level of country-specific detail 

will help analysts more accurately calculate benefits and hence breakeven prices. 

III.1.5 Summary and Analysis 

The methodology and data discussed in this section describe the MAC analysis conducted for the 

landfill sector by the EMF-21 study. MACs for 2010 and 2020 were estimated based on aggregated 

industry data from each country or region. The MACs represent estimates of potential CH4 mitigation 

from landfills based on available information regarding MSW practices, infrastructure, climate, and 

country reported emissions estimates provided through the United Nation’s Framework Convention on 

Climate Change (FCCC) emissions inventory reports. 

III.1.6 References 

Intergovernmental Panel on Climate Change (IPCC). 1996. Revised 1996 IPCC Guidelines for National 

Greenhouse Gas Inventories: Reference Manual (Volume 3). Available at <http://www.ipcc-nggip. 

iges.or.jp/public/gl/invs6.htm>. As obtained on April 26, 2004. 

U.S. Environmental Protection Agency (USEPA). 1999a. Final Plan for Municipal Solid Waste Landfills. 

Available at <http://www.epa.gov/ttn/atw/landfill/lndfpfs.pdf>. Obtained on May 24, 2004. 

U.S. Environmental Protection Agency (USEPA). 1999b. U.S. Methane Emissions 1990–2020: Inventories, 

Projections, and Opportunities for Reductions. Washington, DC: USEPA. Available at <http://www.epa. 

gov/ghginfo>. 

U.S. Environmental Protection Agency (USEPA). 2003a. Landfill Gas Energy Cost Model Version 1.2. 

Washington, DC: USEPA, Landfill Methane Outreach Program. 

U.S. Environmental Protection Agency (USEPA). 2003b. Municipal Solid Waste in the United States: 2001 

Facts and Figures. EPA530-R-03-011. Washington, DC: USEPA, Office of Solid Waste and Emergency 

Response. 

U.S. Environmental Protection Agency (USEPA). 2003c. International Analysis of Methane and Nitrous Oxide 

Abatement Opportunities: Report to Energy Modeling Forum, Working Group 21. Appendices. Washington, 

DC: USEPA. Available at <http://www.epa.gov/methane/intlanalyses.html>. As obtained on 

September 27, 2004. 

U.S. Environmental Protection Agency (USEPA). 2006. Global Anthropogenic Non-CO2 Greenhouse Gas 

Emissions: 1990–2020. Washington, DC: USEPA. 
SECTION III — WASTE • WASTEWATER 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES III-13 

III.2 Wastewater Sector 

orldwide CH4 from wastewater accounted for more than 523 MtCO2eq in 2000. 

Wastewater is the fifth largest source of anthropogenic CH4 emissions, contributing 

approximately 9 percent of total global CH4 emissions in 2000. India, China, the United 

States, and Indonesia combined account for 49 percent of the world’s CH4 emissions from wastewater 

(see Figure 2-1). Global CH4 emissions from wastewater are expected to grow by approximately 20 

percent between 2005 and 2020. 

Figure 2-1: CH4 Emissions from Wastewater by Country: 2000–2020 

Source: USEPA, 2006. 

Wastewater is also a significant source of nitrous oxide (N2O). Worldwide, N2O emissions from 

wastewater accounted for approximately 91 MtCO2eq in 2000 (see explanatory note 1). Wastewater as a 

source is the sixth largest contributor to N2O emissions, accounting for approximately 3 percent of N2O 

emissions from all sources. Indonesia, the United States, India, and China accounted for approximately 50 

percent of total N2O emissions from domestic wastewater in 2000 (see Figure 2-2). Global N2O emissions 

from wastewater are expected to grow by approximately 13 percent between 2005 and 2020. This chapter 

only discusses the mitigation options that may be available to control CH4 at wastewater treatment 

plants. No formal MAC analysis is presented for this sector because data are insufficient on wastewater 

systems’ infrastructure and abatement technology costs. 

III.2.1 Introduction 

Wastewater from domestic (sewage) and industrial sources is typically moved through a wastewater 

sewer system to a centralized wastewater management treatment center. At the treatment center, soluble 

organic material, suspended solids, pathogenic organisms, and chemical contaminants are removed from 

water using biological processes in which microorganisms consume the organic waste. This results in the 

production of biomass sludge. The microorganisms can perform this biodegradation process in aerobic 

and anaerobic environments, the former producing CO2 and the latter producing CH4. 

W 

0

100

200

300

400

500

600

700

2000 2010 2020

Year

MtCO2eq

Indonesia

United States

China

India

Rest of the world
SECTION III — WASTE • WASTEWATER 

III-14 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

Figure 2-2: N2O Emissions from Wastewater by Country: 2000–2020 

Source: USEPA, 2006. 

Wastewater treatment plants (WWTP) may be located on-site or off-site. In the case of domestic 

wastewater, septic tanks are an example of an on-site treatment plant for domestic wastewater, while a 

centralized municipal WWTP is an example of an off-site facility. The USEPA estimates that 25 percent of 

domestic wastewater is treated through on-site facilities such as septic tanks (USEPA, 2004). Centralized 

WWTP requires that the wastewater be transported to the facility through a municipal sewer system. 

III.2.1.1 Emissions from Wastewater Systems 

CH4 is produced by decay of organic material in wastewater as it decomposes in anaerobic 

environments. CH4 emissions from wastewater are determined by the amount of organic material 

produced and the extent to which this material is allowed to decompose under anaerobic conditions. The 

organic content of wastewater is typically expressed in terms of either biochemical oxygen demand 

(BOD) or chemical oxygen demand (COD) (IPCC, 1996a). Most developed countries use centralized 

aerobic wastewater treatment facilities with closed anaerobic sludge digester systems to process 

municipal and industrial wastewater. Employment of these practices increases CH4 generation but 

ultimately reduces baseline emissions. 

N2O is produced during both the nitrification and denitrification of urea, ammonia, and proteins. 

These waste materials are converted to nitrate (NO3) via nitrification, an aerobic process converting 

ammonia-nitrogen to nitrate. Denitrification occurs under anoxic conditions (without free oxygen) and 

involves the biological conversion of nitrate into dinitrogen gas (N2). N2O can be an intermediate product 

of both processes but is more often associated with denitrification (Sheehle and Doorn, 2001). 

An overview of treatment methods, wastewater composition, and sources of CH4 emissions for 

domestic and industrial wastewater systems is provided below, followed by a discussion of N2O 

emissions. 

0

20

40

60

80

100

120

2000 2010 2020

Year

MtCO2eq

Pakistan

Brazil

United States

China

Rest of the world
SECTION III — WASTE • WASTEWATER 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES III-15 

Domestic Wastewater 

The process of treating domestic wastewater (sewage) involves three major phases. First, the 

wastewater collected at a centralized WWTP goes through a primary treatment phase. During this phase, 

large solids are removed through a filtration process where grit is removed and oxygen is added. Next, 

the wastewater enters a primary clarifier that removes almost 95 percent of settleable solids. This process 

takes approximately 30 minutes to an hour, and the initial biodegradation by microorganisms begins. 

Primary sludge is separated from the effluent at this stage. During this process, wastewater is generally 

aerated ensuring that the decomposition of the organic matter occurs in an aerobic environment. 

Following the primary treatment, it is common to subject the remaining effluent to a secondary 

treatment. During this phase, the effluent undergoes bio-oxidation through an aerobic process in which 

aerobic microorganisms break down any remaining organic solids. In the secondary treatment, the 

effluent is passed through a trickling filter or aeration basin for approximately 4 to 6 hours. Next, the 

remaining effluent moves into a final clarifier where further biodegradation can occur. This secondary 

treatment produces additional secondary sludge (biomass). Following the secondary treatment, the 

effluent is released to a receiving stream. 

The sludge (biomass) produced during the primary and secondary phases of treatment is then 

combined and moved into an encapsulated silo-like digester where it undergoes an anaerobic 

decomposition process using microorganisms that continue to break down the organics. The digester 

comprises a holding tank, a gas capture system, and a heating element. Over a period of time (weeks), 

microorganisms break down the large organic molecules in the feed sludge. Still smaller organisms 

convert this organic material into CH4 and CO2. On average, 40 to 45 percent of feed sludge is converted 

to CH4 and CO2 during the process. The CH4 produced is closely monitored for safety concerns and then 

combusted either in the form of a flare or used to generate heat required during this process. The 

remaining sludge is sent to landfills. 

Industrial Wastewater 

Industries producing large volumes of wastewater and industries with high organic COD wastewater 

load are likely to have significant CH4 emissions. In the United States, the meat and poultry, pulp and 

paper, and produce (i.e., fruits and vegetable) industries are the largest sources of industrial wastewater 

and contain high organic COD. These industries are also considered CH4-emitting industries because 

they employ either shallow lagoons or settling ponds in their treatment of wastewater, which promotes 

anaerobic degradation. 

The meat and poultry industry in the United States has been identified as a major source of CH4

emissions because of its extensive use of anaerobic lagoons in sequence to screening, fat traps, and 

dissolved air flotation. It is estimated that 77 percent of all wastewater from the meat and poultry 

industry degrades anaerobically (USEPA, 1997a). 

Treatment of industrial wastewater from the pulp and paper industry is similar to the treatment of 

municipal wastewater. Treatment in this industry generally includes neutralization, screening, 

sedimentation, and flotation/hydrocycloning to remove solids. Anaerobic conditions are most likely to 

occur during lagooning for storage, settling, and biological treatment (secondary treatment). During the 

primary treatment phase, lagoons are aerated to reduce anaerobic activity. However, the size of these 

lagoons makes it possible for zones of anaerobic degradation to take place. Approximately half of the 

initial COD remains following the primary treatment. This remaining COD is passed into a secondary 

treatment phase where anaerobic degradation is more likely to take place. The USEPA estimates that 25 

percent of COD in secondary treatment lagoons degrades anaerobically (USEPA, 1997b). 
SECTION III — WASTE • WASTEWATER 

III-16 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

The fruit, vegetable, and juice-processing industries generate large amounts of wastewater. The 

treatment of wastewater from these industries generally includes screening, coagulation/settling, and 

biological treatment (lagooning), while effluent is typically discharged into municipal sewer system. 

Anaerobic degradation can occur within the lagoons during biological treatment. In the United States it is 

assumed that these lagoons are intended for aerobic operation, but during peak seasonal usage, anaerobic 

conditions may occur. The USEPA estimates that approximately 5 percent of wastewater organics 

degrade anaerobically (Sheehle and Doorn, 2001). 

N2O from Wastewater 

The two most significant sources of N2O identified in the United States are emissions from 

wastewater treatment processes and emissions from effluent discharge into aquatic environments. IPCC 

assumes that nitrogen disposal associated with land disposal, subsurface disposal, and domestic 

wastewater treatment are negligible as sources of N2O emissions. Generally countries use the IPCC 

methodology (IPCC, 2000) for estimating national emissions from wastewater. However, current 

methodologies do not allow for a complete estimate of N2O emissions. As a result, N2O baselines 

reported in this chapter represent the human sewage component only; no methodology exists to estimate 

N2O emissions from industrial wastewater. 

The remainder of this chapter discusses the activity data and emissions factors used to develop 

baseline emissions and CH4 MACs for wastewater systems. The chapter concludes with a discussion of 

uncertainties and limitations. 

III.2.2 Baseline Emissions Estimates 

CH4 generation occurs as organic matter undergoes decomposition in anaerobic conditions. 

However, CH4 generation varies widely depending on waste management techniques. Specifically 

engineered environments can increase the CH4 generation rates. 

The quantity of CH4 generated can be expressed in terms of several key activity and emissions 

factors: 

Domestic Wastewater 

CH4 Generation = (POP) * (BOD) * (PAD) * (CH4P) (2.1) 

where 

POP = total population, 

BOD = production of BOD per capita per year, 

PAD = percentage of BOD anaerobically digested per year, and 

CH4P = CH4 generation potential per kg of BOD.1

Industrial Wastewater 

CH4 Generation = (IP) * (COD) * (PAD) * (CH4P) (2.2) 

 

1 IPCC emissions factor of 0.6 kilogram CH4 per kilogram of BOD, cited in the USEPA’s Inventory of U.S. Greenhouse 

Gas Emissions and Sinks: 1990–2002. 
SECTION III — WASTE • WASTEWATER 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES III-17 

where 

IP = industry production, 

COD = production of COD per unit of output, 

PAD = percentage of COD anaerobically digested per year, and 

CH4P = CH4 generation potential per kg of COD.2

III.2.2.1 Activity Factors 

Activity factors determine the quantity of wastewater produced and the intensity of organic content 

(see explanatory note 2). Domestic wastewater production is related to the population size. The 

population size, in conjunction with the level of organic waste present in the wastewater (BOD), 

determines a country’s CH4 generation potential. The per capita production of BOD may vary over time 

or by country depending on a population’s consumption preferences. 

Industrial wastewater generation is based largely on the annual product output from major 

wastewater-producing industries, including meat and poultry packing; pulp and paper manufacturing; 

and vegetable, fruits, and juices processing. Differences in production processes and recycling practices 

can influence the COD per unit of production in these industries. 

N2O production is typically estimated using an activity factor of annual per capita protein 

consumption (kilograms per year). However, it has been suggested that this factor alone underestimates 

the actual amount of protein entering wastewater treatment systems. Food (waste) that is not consumed 

is often washed down the drain using garbage disposals. In addition, laundry water can contribute to 

nitrogen loadings. For these reasons, multipliers are commonly applied to the annual per capita protein 

consumption activity factor to account for these other sources of nitrogen loading. 

Historic Activity Data 

Wastewater production is directly related to a country’s domestic population and industrial 

production of select industries. Population growth rates are traditionally higher in developing countries, 

while more industrialized countries have recently tended to experience smaller increases in population 

over time. Along with population growth, production of BOD per capita has also been growing, which 

means that more organic material is present in wastewater. Increases in BOD per capita can result from 

various economic improvements, which could lead to a change in the availability of food types and 

consumption preferences. 

Industrial growth rates and treatment practices differ by country. Whereas most developed and 

developing countries have thriving meat and poultry and produce industries, differences exist in the local 

regulation and treatment practices. Developing countries are more likely to employ lagoons or settling 

ponds in their treatment of industrial waste, which promotes anaerobic degradation. 

Projected Activity Data 

Both domestic and industrial wastewater production are expected to increase in the future as 

populations continue to grow and key industries continue to expand. 

 

2 IPCC emissions factor of 0.25 kilogram CH4 per kilogram of COD, cited in the USEPA’s Inventory of U.S. Greenhouse 

Gas Emissions and Sinks: 1990–2002. 
SECTION III — WASTE • WASTEWATER 

III-18 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

III.2.2.2 Emissions Factors and Related Assumptions 

The primary determinants of wastewater emissions factors are 

• CH4 generation potential per unit of BOD or COD and 

• the percentage of BOD or COD that degrades in anaerobic conditions. 

CH4 generation potential per unit of BOD or COD is likely to remain constant because this is a 

measure of chemical potential, not the result of varying preferences. However, wastewater management 

practices vary across cities and countries, affecting the percentage of BOD or COD that degrades under 

anaerobic conditions. Even for managed systems, differences in operations and maintenance can result in 

unintended anaerobic conditions that lead to additional CH4 emissions. 

Historical Emissions Factors 

A CH4 generation factor of 0.6 kilogram CH4 per kilogram BOD is provided in the IPCC Good 

Practice Guidance (IPCC, 2000) for domestic wastewater. This generation factor is also applied to the 

pulp and paper and meat and poultry industries. A CH4 generation factor of 0.4 kg CH4 per kilogram 

BOD is applied to the fruit, vegetable, and juice-processing industries. This generation factor represents 

the potential CH4 generation from a given unit of BOD, assuming that a unit of BOD degrades under 

anaerobic conditions. 

Most developed countries have adopted municipal wastewater treatment practices that prevent the 

formation of anaerobic conditions in managing and treating wastewater. Developing countries have 

traditionally employed wastewater management practices that foster controlled anaerobic environments 

where the CH4 is captured for flaring or direct use. Settling ponds that are open to the atmosphere are 

typically aerated to promote the production or CO2 as opposed to CH4. However, in developing 

countries, industries, such as the pulp and paper or meat and poultry, are less likely to have adopted 

practices to prevent anaerobic degradation of COD in wastewater. 

Projected Emissions Factors 

Projected emissions factors from wastewater are expected to follow historic trends. The CH4

generation potential per unit of BOD will remain constant over time. Improvements to wastewater 

management practices are projected to occur with increased GDP. These improvements may result in 

decreased baseline emissions for developing countries. As developing countries adopt better 

management practices, their baseline emissions will approach the baselines of developed countries with 

established wastewater infrastructure already in place. Overall, reductions in CH4 emissions factors from 

wastewater will occur because of improvements in wastewater management and treatment. 

III.2.2.3 Emissions Estimates and Related Assumptions 

This section discusses the historical and projected baseline emissions from wastewater. As shown in 

Equations (2.1) and (2.2), the amount of CH4 generated each year from wastewater is determined by a 

country’s population, the per capita production of BOD or COD (in the industry), and the percentage of 

BOD that degrades under anaerobic conditions. 

Historical Emissions Estimates 

Tables 2-1 and 2-2 provide emissions by country for CH4 and N2O. Historically, China and India have 

the largest baseline CH4 and N2O emissions from wastewater. China and India are the two most 

populous countries in the world with 1.3 and 1.1 billion people, respectively, in 2002 (World Bank, 2005). 

Their large populations in highly concentrated urban areas, combined with limited infrastructure for 
SECTION III — WASTE • WASTEWATER 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES III-19 

Table 2-1: CH4 Emissions from Wastewater by Country: 1990–2000 (MtCO2eq) 

Country 1990 1995 2000 

India 81.8 89.7 97.6 

China 94.4 99.7 104.2 

United States 24.9 29.9 34.3 

Indonesia 18.0 19.5 20.9 

Brazil 18.0 19.3 20.7 

Pakistan 10.9 12.2 14.0 

Bangladesh 10.4 11.7 13.0 

Mexico 10.0 11.0 11.9 

Nigeria 6.8 7.9 9.0 

Philippines 6.2 7.0 7.7 

Viet Nam 6.7 7.4 8.0 

Iran 6.0 6.6 7.2 

Turkey 5.7 6.3 6.8 

Russian Federation 9.4 9.4 9.3 

Ethiopia 3.9 4.5 5.1 

Rest of the world 132.8 141.7 152.7 

World Total 445.9 483.8 522.5 

Source: USEPA, 2006. 

Table 2-2: N2O Emissions from Wastewater by Country: 1990–2000 (MtCO2eq) 

Country 1990 1995 2000 

China 17.6 18.5 19.4 

United States 13.0 14.2 15.6 

Brazil 3.7 3.7 4.0 

Pakistan 1.8 2.0 2.3 

Indonesia 2.1 2.3 2.5 

Russian Federation 3.7 3.6 3.4 

India 2.0 2.2 2.4 

Germany 2.2 2.2 2.2 

Nigeria 1.0 1.1 1.3 

Iran 1.3 1.4 1.6 

Mexico 1.3 1.4 1.6 

Bangladesh 0.9 1.1 1.2 

Saudi Arabia 0.7 0.8 0.9 

Viet Nam 1.0 1.1 1.2 

Egypt 0.9 1.0 1.1 

Rest of the world 27.4 28.4 30.3 

World Total 80.7 85.1 90.8 

Source: USEPA, 2006. 
SECTION III — WASTE • WASTEWATER 

III-20 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

handling wastewater, result in substantial emissions. Similar conditions exist in Cambodia and Indonesia 

where densely populated areas produce significant CH4 emissions. 

Projected Emissions Estimates 

Worldwide CH4 emissions from wastewater are expected to increase in both developed and 

developing countries because of expanding populations and increases in GDP. Tables 2-3 and 2-4 list 

projected baseline emissions by country for CH4 and N2O. India is projected to replace China as the 

world’s leading emitter of wastewater CH4. The World Bank projects India’s average annual growth rate 

in population of 1.2 percent over the next 10 years, while China’s is projected to be 0.6 percent over the 

same time period (World Bank, 2005). Although both countries’ GDP is projected to increase over time, 

the most influential factor in determining each country’s baseline will be the extent to which these 

countries improve their wastewater management practices. 

III.2.3 Emissions Reductions from Wastewater 

Components of abatement options for the wastewater sector include the incremental addition of CH4

mitigation equipment not already included in the initial construction of a municipal wastewater 

treatment plant. This section discusses opportunities for emissions reductions beyond existing baseline 

practices qualitatively but, because of data limitations, does not attempt to model MACs. 

III.2.3.1 Abatement Option Opportunities 

We describe two approaches to reducing CH4 emissions from wastewater following the 

implementation of municipal infrastructure: 

• improved wastewater treatment practices (domestic and industrial) and 

• anaerobic digester with collection and flaring or cogeneration. 

Improved wastewater treatment practices include reducing the amount of organic waste anaerobically 

digested. This reduction can be achieved through improved aeration and/or the scaling back of the use of 

stagnant settling lagoons. Costs for improving treatment practices vary widely based on the technology 

applied and specific characteristics of the wastewater. Improvements to existing wastewater treatment 

practices assume that infrastructure is already in place and that the cost of any improvements would 

represent the incremental addition of technology as a capital improvement or increases in O&M costs. 

Anaerobic digesters can be flared or the CH4 used for cogeneration to reduce CH4 emissions from 

biomass or liquid effluents with high organic content. The IPCC estimates construction costs for 

anaerobic digesters to be $0.1 to $3 million (IPCC, 1996b). This estimate includes the construction of a 

collection system and either a flare or a utilization system. IPCC estimates annual O&M costs for this type 

of system at between $10,000 and $100,000, assuming wastewater flows of 0.1 to 100 million gallons (400 

to 0.4 x 106 m3) per day (IPCC, 1996b). 
SECTION III — WASTE • WASTEWATER 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES III-21 

Table 2-3: Projected Baseline CH4 Emissions from Wastewater by Country: 2005–2020 (MtCO2eq) 

Country 2005 2010 2015 2020 

India 105.4 112.7 119.1 125.0 

China 108.0 111.7 115.3 118.3 

United States 35.2 36.1 37.0 37.8 

Indonesia 22.2 23.5 24.7 25.9 

Brazil 22.0 23.2 24.4 25.5 

Pakistan 15.9 18.0 20.2 22.6 

Bangladesh 14.5 15.9 17.4 18.8 

Mexico 12.8 13.6 14.4 15.1 

Nigeria 10.3 11.6 13.1 14.6 

Philippines 8.5 9.2 9.8 10.3 

Viet Nam 8.5 9.0 9.6 10.2 

Iran 7.7 8.2 8.9 9.5 

Turkey 7.3 7.7 8.1 8.5 

Russian Federation 9.0 8.7 8.5 8.3 

Ethiopia 5.8 6.5 7.3 8.2 

Rest of the world 165.2 178.3 192.2 206.4 

World Total 558.1 594.0 629.9 665.0 

Source: USEPA, 2006. 

Table 2-4: Projected Baseline N2O Emissions from Wastewater by Country: 2005–2020 (MtCO2eq) 

Country 2005 2010 2015 2020 

China 20.1 20.8 21.5 22.0 

United States 15.7 15.9 16.1 16.3 

Brazil 4.2 4.5 4.7 4.9 

Pakistan 2.6 2.9 3.3 3.7 

Indonesia 2.6 2.8 2.9 3.0 

Russian Federation 3.3 3.2 3.1 3.0 

India 2.5 2.7 2.9 3.0 

Germany 2.2 2.2 2.2 2.2 

Nigeria 1.5 1.7 1.9 2.1 

Iran 1.7 1.8 1.9 2.1 

Mexico 1.7 1.8 1.9 2.0 

Bangladesh 1.3 1.4 1.6 1.7 

Saudi Arabia 1.1 1.2 1.4 1.6 

Viet Nam 1.3 1.4 1.5 1.6 

Egypt 1.2 1.3 1.4 1.5 

Rest of the world 31.9 33.4 35.0 36.5 

World Total 95.0 99.1 103.2 107.2 

Source: USEPA, 2006. 
SECTION III — WASTE • WASTEWATER 

III-22 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

III.2.3.2 Uncertainties and Limitations 

Uncertainty and limitations persist despite attempts to incorporate all publicly available information 

on international wastewater sectors. Limited information on the wastewater systems of developing 

countries increases this uncertainty. Additional information would improve the accuracy of baseline 

emissions projections. 

• BOD Production Rates: Improved information on specific population diets and consumption 

habits would greatly improve the analyst’s ability to calculate baseline emissions. 

• Country-Specific Waste Management Practices: Improved documentation of wastewater 

management practices would allow deviations from the normal assumption, allowing countryby-country estimates of percentage of BOD undergoing anaerobic degradation. 

• Improved Cost Data: Improved documentation of wastewater CH4 abatement options and their 

cost components would improve the analyst’s ability to estimate baseline reductions given some 

estimate of market penetration. 

III.2.4 Summary 

The data discussed in this chapter demonstrate that wastewater is a significant source of greenhouse 

gas emissions. However, policy approaches directly targeted at mitigating CH4 emissions from 

wastewater are limited, and no specific abatement options are presented as part of the analysis in this 

chapter. Several factors contribute to difficulties in developing MACs for wastewater abatement options. 

The primary factor for determining emissions from the wastewater sector (in terms of CH4 emissions 

per BOD) is the type of treatment system employed to manage the waste. Centralized, managed 

treatment facilities can control anaerobic environments and have a greater potential to capture and use 

CH4. Because most centralized systems automatically either flare or capture and use CH4 for safety 

reasons, “add-on” abatement options do not exist. As a result, potential emissions reductions depend on 

large-scale structural changes in waste management practices. In contrast, smaller decentralized systems 

have less control over the share of aerobic versus anaerobic decomposition and have few feasible options 

for capturing CH4. 

At issue is that overriding economic and social factors influence wastewater treatment practices 

throughout the world. The benefits of installing a wastewater system in a developing country for the 

purpose of disease reduction greatly outweigh potential benefits associated with CH4 mitigation. This is 

not to say that CH4 mitigation is not one of many factors to be potentially considered in selecting 

wastewater treatment systems. However, because of the scope of the costs and benefits of the investment 

decision, it would be misleading to imply that potential carbon prices (reflected in MACs) would be the 

driving force behind investment decisions that influence CH4 emissions from wastewater. 

III.2.5 References 

Intergovernmental Panel on Climate Change (IPCC). 1996a. Revised 1996 IPCC Guidelines for National 

Greenhouse Gas Inventories: Reference Manual (Volume 3). Available at <http://www.ipcc-nggip 

.iges.or.jp/public/gl/invs6.htm>. As obtained on April 26, 2004. 

Intergovernmental Panel on Climate Change (IPCC). 1996b. Technologies, Policies, and Measures for 

Mitigating Climate Change. Available at < http://www.gcrio.org/ipcc/techrepI/index.html>. As obtained 

on February 25, 2004. 
SECTION III — WASTE • WASTEWATER 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES III-23 

Intergovernmental Panel on Climate Change (IPCC). 2000. Good Practice Guidance and Uncertainty 

Management in National Greenhouse Gas Inventories. Intergovernmental Panel on Climate Change, 

National Greenhouse Gas Inventories Programme, Montreal, IPCC-XVI/DOC. 10 (1.IV.2000). 

Available at <http://www.ipcc-nggip.iges.or.jp/public/gpglulucf/gpglulucf.htm>. As obtained on 

January 10, 2005. 

Scheehle, E.A., and M.R.J. Doorn. 2001. “Improvements to the U.S. Wastewater Methane and Nitrous 

Oxide Emissions Estimates.” Working paper. Washington, DC. 

U.S. Environmental Protection Agency (USEPA). 1997a. “Estimate of Global Greenhouse Gas Emissions 

from Industrial Wastewater Treatment.” Washington, DC: USEPA. EPA-600/R-97-091. 

U.S. Environmental Protection Agency (USEPA). 1997b. Supplemental Technical Development Document for 

Effluent Limitations Guidelines and Standards for the Pulp, Paper, and Paperboard Point Source Category. 

EPA-821-R-97-001. Washington, DC: USEPA. 

U.S. Environmental Protection Agency (USEPA). 2004. Inventory of U.S. Greenhouse Gas Emissions and Sinks 

1990–2002. Washington, DC: USEPA, Office of Solid Waste and Emergency Response. Available at 

<http://www.epa.gov/methane/ intlanalyses.html>. As obtained on October 17, 2004. 

U.S. Environmental Protection Agency (USEPA). 2006. Global Anthropogenic Non-CO2 Greenhouse Gas 

Emissions: 1990–2020. Washington, DC: USEPA. 

World Bank Group. 2005. 2004—World Development Indicators: Table 2.1 Population Dynamics. Available at 

<http://www.worldbank.org/data/databytopic/population.html>. As obtained on February 24, 2005. 
SECTION III — WASTE • WASTEWATER 

III-24 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

Explanatory Notes 

1. Assuming a global warming potential (GWP) value of 310. 

2. The wastewater treatment practices that determine the share of BOD that degrades under anaerobic 

conditions are included in the emissions factor discussion. 
Section III: Waste Sector Appendixes 

Appendixes for this section are available for download from the USEPA’s Web site at 

http://www.epa.gov/nonco2/econ-inv/international.html. 

IV. Industrial Processes 
SECTION IV — INDUSTRIAL PROCESSES • PREFACE 

IV-ii GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

This section presents international emissions baselines and marginal abatement curves (MACs) for 11 

industrial sources. Each chapter in this section addresses one of these sources. These sources include 

nitrous oxide (N2O) emitted during nitric and adipic acid production; fluorinated gases that are used as 

substitutes for ozone-depleting substances (ODSs); and high–global warming potential (GWP) gases, 

including hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), and sulfur hexafluoride (SF6) from 

several industrial sources. MAC data are presented in both percentage reduction and absolute reduction 

terms relative to the baseline emissions. These data can be downloaded in spreadsheet format from the 

U.S. Environmental Protection Agency (USEPA) Web site at <http://www.epa.gov/nonco2/econinv/international.html>. 

The Section IV—Industrial Processes chapters are organized as follows: 

Nitric Oxide 

IV.1 N2O Emissions from Nitric and Adipic Acid Production 

Fluorinated Gases Used as Substitutes for ODSs 

IV.2 HFC Emissions from Refrigeration and Air-Conditioning 

IV.3 HFC, HFE, and PFC Emissions from Solvents 

IV.4 HFC Emissions from Foams 

IV.5 HFC Emissions from Aerosols 

IV.6 HFC Emissions from Fire Extinguishing 

High-GWP Gases from Industrial Processes 

IV.7 PFC Emissions from Aluminum Production 

IV.8 HFC-23 Emissions from HCFC-22 Production 

IV.9 PFC and SF6 Emissions from Semiconductor Manufacturing 

IV.10 SF6 Emissions from Electric Power Systems 

IV.11 SF6 Emissions from Magnesium (Mg) Production 
SECTION IV — INDUSTRIAL PROCESSES • PREFACE 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES IV-iii

IV. Industrial Processes Overview 

his section presents international emission baselines and MACs for twelve sources of various 

greenhouse gases, including N2O, HFCs, PFCs, and SF6. These sources include production of 

nitric and adipic acid, which emit N2O; production of aluminum, magnesium, semiconductors, 

and HCFC-22, which emit PFCs, SF6, and HFCs; and use of electrical equipment in electric power 

systems, which emits SF6. In addition to the industrial sectors, this section also includes emissions 

estimates and MACs for fluorinated gases (generally HFCs) that are used as substitutes for ODSs. 

While a single set of baseline emissions estimates is presented for most industrial processes covered 

in this section, five subsectors have dual baselines and MACs. These processes are the production of 

aluminum, semiconductors, Mg, and HCFC-22, and the use of electrical equipment. For all five of these 

industries, clearly defined, industry-specific global or regional emissions reduction goals have been 

announced. First, in response to concerns regarding the high GWPs and long lifetimes of their emissions, 

the global aluminum, semiconductor, and Mg industries have committed to reduce future emissions by 

substantial percentages. Second, users (and, in some cases, manufacturers) of electrical equipment in 

Japan, Europe, and the United States have committed to reduce emissions in those countries and regions. 

Finally, HCFC-22 producers in several developing countries have agreed to host mitigation projects 

funded by developed countries under the Clean Development Mechanism (CDM) of the Kyoto Protocol. 

The HFC-23 abatement projects considered in this analysis are either registered or are in the process of 

being registered in the CDM pipeline. (HCFC-22 producers in developed countries are also continuing to 

reduce emissions.) These global and regional emissions reduction goals are summarized in the table 

below. 

Table: Global and Regional Emissions Reduction Commitments

Industry 

Global Industry Association, 

Region, or Country 

Percentage of World 

Production/Emissions in 

2003 Goal 

Semiconductor 

manufacturing 

World Semiconductor Council 85% Reduce fluorinated emissions to 

90% of 1995 level by 2010 

Mg production International Magnesium 

Association 

80% of the magnesium industry is 

outside of China; about 80% of 

global SF6 emissions 

Phaseout SF6 use by 2011 

Aluminum 

production 

International Aluminum Institute 70% (but goal applies to entire 

industry) 

Reduce PFCs/ton of aluminum 

by 80% relative to 1990 levels 

by 2010 

Electrical 

equipment (use) 

EU-25+3, Japan, and United 

States 

40% of use emissions Country-specific reductions from 

2003 totaling 2.5 MtCO2eq, or 

15% of these countries’ 2003 

emissions from use 

HCFC-22 China, India, Korea, and Mexico 65% of emissions CDM projects totaling 55 

MtCO2eq, or 63% of these 

countries’ 2010 emissions 

T 
SECTION IV — INDUSTRIAL PROCESSES • PREFACE 

IV-iv GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

The first scenario presented in this report, called the “technology-adoption baseline,” is based on the 

assumption that these industries will achieve their announced global or regional emissions reduction 

goals for the year 2010. The second scenario, called the “no-action baseline,” is based on the assumption 

that emissions rates will remain constant from the present onward in these industries. 

The USEPA believes that actual future emissions are likely to be far closer to those envisioned in the 

technology-adoption baseline than those envisioned in the no-action baseline. Since 1990, all five 

industries have already made great progress in reducing their emissions rates, and research is continuing 

into methods to further reduce those rates. Nevertheless, additional actions will be required to actually 

realize additional reductions. These actions range from process optimization and chemical recycling to 

chemical replacement. In some cases, the actions are estimated to carry net private costs; in others, net 

private benefits. 

The MACs for the technology-adoption baseline have been adjusted to reflect the implementation of 

some options in the baseline. When an option is assumed to be adopted in the baseline, the emissions 

stream to which that option is applied in the MAC is correspondingly decreased, so that options that are 

fully implemented in the technology-adoption baseline are not present in the technology-adoption MAC 

at all. 

Depending on the context, either set of baselines and MACs may be of interest. For example, analysts 

interested in the incremental costs of reducing emissions below the levels anticipated in current global 

industry commitments can use the technology-adoption baseline and the associated MACs. On the other 

hand, analysts interested in the future costs of achieving the currently planned industry reductions can 

use the no-action baseline and the associated MACs. The difference between the two baselines is itself of 

interest, demonstrating that the industry commitments are likely to avert very large emissions. 

It should be noted that the USEPA modeled only those reduction efforts that had been clearly 

announced and quantified on an industry-specific basis at the time this report was prepared. This means 

that even in the technology-adoption baseline, significant reduction opportunities remain in 2010 and 

2020, primarily in developing countries. This is particularly true for the HCFC-22 and electric power 

system industries. In fact, there is a significant probability that many of these emissions will be averted 

(e.g., by fuller implementation of CDM or other reduction efforts). However, the precise extent of 

additional reduction actions is uncertain. Thus, the technology-adoption baseline reflects only current, 

quantitative, industry-specific goals. 

Past emissions (1990 through 2000) for all five sources are identical under either scenario, but they are 

provided with both scenarios to provide context for the divergent future trends. 

Detailed discussions of the methodology used to develop the baselines for each source can be found 

in the USEPA (2006) report Global Anthropogenic Non-CO2 Greenhouse Gas Emissions: 1990–2020. 
SECTION IV — INDUSTRIAL PROCESSES • NITRIC AND ADIPIC ACID PRODUCTION 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES IV-1

IV.1 N2O Emissions from Nitric and Adipic Acid Production 

orldwide N2O emissions from industrial sources account for more than 154 million metric 

tons of carbon dioxide (CO2) equivalent (MtCO2eq) (USEPA, 2006). The USEPA estimates 

that emissions from nitric and adipic acid production combined contributed 

approximately 5 percent of total global N2O emissions in 2000 (USEPA, 2003). Nitric acid production 

accounts for 67 percent of N2O emissions from industrial production, and adipic acid accounts for the 

remaining 33 percent (USEPA, 2003). 

Eastern Europe, the United States, China, and the European Union (EU-15) combined account for 79 

percent of total N2O emissions from industrial production (Figure 1-1). The Intergovernmental Panel on 

Climate Change (IPCC) reports that the number of nitric acid production plants worldwide is estimated 

at 250 to 600. The United States is the primary producer of adipic acid, with four production sites alone, 

accounting for approximately 40 percent of total adipic acid production worldwide (USEPA, 2001). Other 

countries have at most one adipic acid plant (IPCC, 2000). 

Figure 1-1: N2O Emissions from Industrial Production by Country: 2000–2020 

Source: USEPA, 2006. 

EU-15 = European Union. 

Global N2O emissions from industrial production sources are expected to grow by approximately 13 

percent between 2005 and 2020 (USEPA, 2006), although the percentage distribution of emissions across 

countries is projected to remain relatively unchanged. 

IV.1.1 Introduction 

The two major sources of anthropogenic N2O emissions from industry are production of nitric and 

adipic acid. These dicarboxylic acids produce N2O as a by-product of the production process. N2O is then 

emitted in the waste gas stream (USEPA, 2001). 

W 
SECTION IV — INDUSTRIAL PROCESSES • NITRIC AND ADIPIC ACID PRODUCTION 

IV-2 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

IV.1.1.1 Nitric Acid 

Nitric acid is an inorganic compound, typically used to make synthetic commercial fertilizer. Nitric 

acid is also used in the production of adipic acid, explosives, and metal etching and in the processing of 

ferrous metals. Nitric acid is produced through catalytic oxidation of ammonia (CH4) at high 

temperatures, which creates N2O as a reactionary by-product released from reactor vents into the 

atmosphere (Mainhardt and Kruger, 2000). IPCC believes that nitric acid production now represents the 

majority of N2O emissions from industrial process as a result of implementing abatement technologies at 

adipic acid plants. 

In the United States, the nitric acid industry controls for nitrogen oxides gases using a combination of 

nonselective catalytic reduction (NSCR) and selective catalytic reduction (SCR) technologies (USEPA, 

2004). The NSCR units destroy nitrogen oxides, but they also destroy N2O. However, NSCR is considered 

costly and obsolete at modern plants. NSCR units were commonly installed in production facilities built 

between 1971 and 1977 (USEPA, 2004). The USEPA reports that NSCR is currently used by approximately 

20 percent of the U.S. nitric acid production plants; the majority of the industry uses SCR or extended 

absorption, neither of which is known to reduce N2O (USEPA, 2004). 

IV.1.1.2 Adipic Acid 

Adipic acid is a white crystalline solid used primarily as a component in the production of nylon 

(nylon 6/6). Adipic acid is also used in the manufacture of low-temperature synthetic lubricants, coatings, 

plastics, polyurethane resins, and plasticizers and is used to give some imitation foods a “tangy” flavor. 

Industrial sources report that by 2000, all major adipic acid production plants had implemented 

abatement technologies and consequently have dramatically reduced N2O emissions from this source 

(Mainhardt and Kruger, 2000). 

Adipic acid is produced through a two-stage process during which N2O is generated in the second 

stage. The first stage of manufacturing usually involves the oxidation of cyclohexane to form 

cyclohexanone/cyclohexanol mixture. The second stage entails oxidizing this mixture with nitric acid to 

produce adipic acid. N2O is produced as a by-product during the nitric acid oxidation stage and 

potentially is emitted in the waste gas stream (USEPA, 2004). Emissions from this source vary depending 

on the type of technologies and level of emissions controls employed by a specific facility. 

IV.1.2 Baseline Emissions Estimates 

N2O emissions correlate closely with the production of nitric and adipic acid. This section discusses 

production activity, suggested emissions factors, and the resulting baseline emissions estimates based on 

publicly available reports. 

IV.1.2.1 Activity Factors 

Activity factors characterize the intensity of production in these industries, which, when combined 

with emissions factors, result in an estimated baseline emission. 

Historical Activity Data 

Nitric Acid

Nitric acid production levels closely follow trends in fertilizer consumption, because of nitric acid’s 

role as a major component in fertilizer production (Mainhardt and Kruger, 2000). Trends in fertilizer 

production vary widely across different regions of the world. For example, in Western Europe, because of 

concerns over nutrient runoff, nitrogen-based fertilizer use has been scaled back. However, in regions 
SECTION IV — INDUSTRIAL PROCESSES • NITRIC AND ADIPIC ACID PRODUCTION 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES IV-3

where agriculture accounts for a larger share of the gross domestic product (GDP), such as Asia, South 

America, and the Middle East, nitrogen-based fertilizer production capacity is increasing (Mainhardt and 

Kruger, 2000). 

The actual number of nitric acid production plants globally is unknown. Previous reports cited by the 

IPCC have suggested the number to be between 250 and 600. This uncertainty is due to the fact that many 

nitric acid plants are often part of larger facilities that manufacture products using nitric acid, such as 

fertilizer and explosives facilities (Mainhardt and Kruger, 2000). 

Adipic Acid

Adipic acid is used primarily in the production of nylon. As a result, production of adipic acid is 

closely correlated with the world’s nylon production. Global demand for engineering plastics has 

increased over time, resulting in major expansion in production capacity in North America and Western 

Europe and new facilities in the Asia Pacific region. In the United States, adipic acid production increased 

by approximately 50 percent between 1990 and 2000 (USEPA, 2004). 

Global capacity for adipic acid was approximately 2.8 million metric tons in 2003. Table 1-1 lists 

estimated adipic acid production capacity in 2003 by country. Demand for adipic acid was estimated at 

2.21 million metric tons for the same year (Chemical Week [CW], 2003). As a result of this oversupply in the 

global market, many adipic acid facilities have been operating at an average rate of 85 percent of capacity. 

Table 1-1: 2003 Adipic Acid Production Capacity (Thousands of Metric Tons/Year) 

Country Adipic Acid Capacity 

United States 1,002.0 

Germany 408.0 

France 320.0 

United Kingdom 220.0 

Canada 170.0 

South Korea 135.0 

China 127.0 

Japan 122.0 

Singapore 114.0 

Brazil 80.0 

Italy 70.0 

Ukraine 56.0 

World Total 2,824.0 

Source: CW, 2003. 

Projected Activity Data 

Nitric Acid

Nitric acid production is expected to increase over time (Mainhardt and Kruger, 2000). The Global 

Emissions Report, from which the emissions projections came, used data that did not report specific 

country activity. Projected production data for nitric acid production were unavailable at the time of 

publication of this report. 
SECTION IV — INDUSTRIAL PROCESSES • NITRIC AND ADIPIC ACID PRODUCTION 

IV-4 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

Adipic Acid

Industrial demand for adipic acid is expected to continue to increase by approximately 2 percent per 

year between 2003 and 2008 (CW, 2003). Nylon 6,6 accounts for approximately 70 percent of demand for 

adipic acid. The demand for fiber-grade nylon 6,6 is projected to grow by 1 percent per year, whereas 

engineering-grade nylon 6,6 is projected to grow by 4.5 percent per year. The dramatic growth in 

engineering-grade nylon is a result of its increased use as a substitute for metal in under-the-hood 

automotive applications (CW, 2003). 

IV.1.2.2 Emissions Factors and Related Assumptions 

Nitric Acid 

The IPCC reports that N2O emissions factors for nitric acid production remain relatively uncertain, 

because of a lack of information on manufacturing processes and emissions controls. The emissions factor 

is estimated, based on the average amount of N2O generated per unit of nitric acid produced, combined 

with the type of technology employed at a plant. The IPCC uses a default range of 2 to 9 kilograms N2O 

per ton of nitric acid produced. As a result, emissions factors for nitric acid production plants may vary 

significantly based on the type of technology employed at the plant. For example, NSCR is very effective 

at destroying N2O, whereas alternative technologies such as SCR and extended absorption do not reduce 

N2O emissions. 

In the United States, a weighted average of 2 kilograms N2O per ton nitric acid is used for plants 

using NSCR systems, and 9.5 kilograms N2O per ton nitric acid is used for plants not equipped with 

NSCR. Table 1-2 lists the reported emissions factors by IPCC in the Revised 1996 Reference Manual. 

Table 1-2: IPCC Emissions Factors for Nitric Acid Production in Select Countries 

Country Nitric Acid Emissions Factors 

United States 2.0–9.0a

Norway—modern, integrated plant < 2.0 

Norway—atmospheric-pressure plant 4.0–5.0 

Norway—medium-pressure plant 6.0–7.5 

Japan 2.2–5.7 

Source: IPCC, 1996. 

a Emissions factors up to 19 kilograms per ton nitric acid have been reported for plants not equipped with NSCR technology.

The IPCC points out that potential emissions factors as high as 19.5 kilograms N2O per ton of nitric 

acid have been estimated in previous reports. In addition, estimates of 80 percent of the nitric acid plants 

worldwide do not employ NSCR technology, which makes it more likely that the default range of 

potential emissions factors provided by the IPCC greatly underestimates the true emissions baselines 

(Mainhardt and Kruger, 2000). 

Adipic Acid 

The IPCC provides countries with a default emissions factor of 300 kilograms N2O per ton of adipic 

acid produced. This emissions factor assumes that no N2O control system is in place. This factor was 

developed using laboratory experiments measuring the reactionary stoichiometry for N2O generation 

during the production of adipic acid (Mainhardt and Kruger, 2000). This emissions factor has been 

supported by some selected measurement at industrial plants. IPCC recommends using plant-specific 

data for those plants with abatement controls already in place (IPCC, 1996). 
SECTION IV — INDUSTRIAL PROCESSES • NITRIC AND ADIPIC ACID PRODUCTION 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES IV-5

IV.1.2.3 Emissions Estimates and Related Assumptions 

This section discusses the historical and projected baseline emissions from the industrial process 

sector for the production of nitric and adipic acid. 

Historical Emissions Estimates 

Table 1-3 lists historical N2O emissions by country. Worldwide N2O baseline emissions from nitric 

and adipic acid production decreased by 28 percent between 1990 and 2000. The United Kingdom, 

Germany, and Canada experienced the largest declines in baselines emissions, with 88 percent, 84 

percent, and 77 percent declines, respectively, over the same 10-year period. However, countries such as 

China, Japan, South Korea, and India saw baseline increases of 54, 29, 25, and 29 percent, respectively. 

Table 1-3: N2O Emissions from Nitric and Adipic Acid Production: 1990–2000 (MtCO2eq) 

Country 1990 1995 2000 

China 19.6 27.5 30.1 

United States 33.1 37.1 25.6 

France 24.1 26.2 11.5 

South Korea 5.7 6.1 7.1 

Italy 6.7 7.1 7.8 

Netherlands 7.6 7.5 7.1 

Brazil 2.5 4.3 5.0 

United Kingdom 29.3 19.0 6.3 

Germany 23.5 25.0 5.5 

Belgium 3.9 4.6 4.6 

Japan 7.4 7.4 4.2 

Poland 5.0 4.9 4.3 

India 2.4 2.8 3.0 

Bulgaria 2.3 1.9 1.3 

Romania 8.9 3.6 2.9 

Rest of the world 41.4 35.0 27.5 

World Total 223.4 220.1 154.0

Source: USEPA, 2006. 

Projected Emissions Estimates 

Table 1-4 lists combined projected N2O baseline emissions from nitric and adipic acid by country. 

Worldwide total N2O emissions from nitric and adipic acid are projected to increase by approximately 16 

percent between 2005 and 2020. The United States, South Korea, and Brazil are expected to experience the 

largest increase in baseline emissions, with 28, 22, and 22 percent, respectively, between 2005 and 2020. 

Nitric Acid

Emissions from nitric acid production are expected to increase by 13 percent between 2000 and 2020, 

because of an expanding market for synthetic fertilizer (see explanatory note 1). Brazil, Mexico, and India 

are projected to increase their N2O baseline emissions by 29, 25, and 22 percent, respectively, from nitric 

acid production (USEPA, 2006). 
SECTION IV — INDUSTRIAL PROCESSES • NITRIC AND ADIPIC ACID PRODUCTION 

IV-6 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

Table 1-4: Projected N2O Baseline Emissions from Nitric and Adipic Acid Production: 2005–2020 (MtCO2eq) 

Country 2005 2010 2015 2020 

China 32.0 34.1 35.5 37.0 

United States 22.4 23.9 25.5 27.2 

India 3.2 3.4 3.6 3.8 

France 12.9 14.3 14.4 14.5 

Italy 8.2 8.6 9.1 9.6 

Brazil 5.5 6.1 6.4 6.7 

Netherlands 7.5 7.7 8.1 8.3 

South Korea 7.9 8.7 9.1 9.6 

United Kingdom 6.3 6.3 6.3 6.3 

Germany 5.7 5.9 6.1 6.2 

Belgium 4.7 4.9 5.1 5.2 

Japan 4.6 4.6 4.8 5.0 

Poland 4.3 4.3 4.3 4.3 

Bulgaria 2.3 2.7 2.9 3.4 

Ukraine 2.4 2.4 2.4 2.4 

Rest of the world 26.5 26.7 26.9 27.2 

World Total 156.5 164.6 170.4 176.6

Source: USEPA, 2006. 

Adipic Acid

Emissions from adipic acid production are projected to increase by approximately 40 percent between 

2000 and 2020, reflecting increased demand for engineering nylon (see explanatory note 1). Southeast 

Asia, Brazil, and Mexico are projected to experience 45, 44, and 39 percent increases, respectively, in 

baseline emissions of N2O. 

IV.1.3 Cost of N2O Emissions Reductions from Industrial Processes 

N2O emissions can be reduced by optimizing the catalytic oxidation of CH4 to nitrogen oxide or by 

decomposing N2O either during the processing of nitric acid or in the tail gas. Currently, N2O reduction 

technologies include extending the reaction process through thermal decomposition in the reaction 

chamber, reducing N2O through catalytic reduction in the reaction chamber, using NSCR or SCR in the 

upstream tail gas expander, or using SCR in the downstream tail gas expander (Smit, Gent, and van den 

Brink, 2001). Each of the technologies has advantages and disadvantages, including the amount of 

utilities required to run the technology, downtime at the plant for installation, consumption of the 

reducing agent, and retrofit limitations at existing plants. Depending on the technology, reduction 

efficiencies can range from 70 percent to 98 percent and costs can range from $0.52 to $9.30 per tCO2eq for 

new installations and $0.86 to $9.48 per tCO2eq. 

Abatement options for the nitric and adipic acid sectors at the time of the Energy Modeling Forum 21 

(EMF-21) analysis were relatively limited. However, more recent innovations have proven effective 

options for abating N2O at nitric acid production plants. The data presented in this report use an average 

reduction and cost of NSCR and SCR technologies. Therefore, the reduction potential is at the high end of 

the reduction range and the costs are on the lower end of the range. Table 1-5 summarizes cost and 

emissions reductions for the abatement options included in the EMF-21 analysis (USEPA, 2003). 
SECTION IV — INDUSTRIAL PROCESSES • NITRIC AND ADIPIC ACID PRODUCTION 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES IV-7

Table 1-5: Cost of Reducing N2O Emissions from Industrial Processes 

Technology 

Breakeven 

Price 

($/tCO2eq) 

Emissions 

Reduction 

(% from 

baseline)a

Emissions 

Reduction in 

2010 

(MtCO2eq) 

Emissions 

Reduction in 

2020 (MtCO2eq) 

Assuming a 10% discount rate and 40% tax rate 

Nitric Acid Sectorb

Grand Paroisse—high-temperature catalytic 

reduction method 

$2.59 6% 0.05 0.05 

BASF—high-temperature catalytic reduction 

method 

$2.36 6% 0.05 0.05 

Norsk Hydro—high-temperature catalytic 

reduction method 

$1.99 7% 0.05 0.06 

HITK—high-temperature catalytic reduction 

method 

$2.75 7% 0.06 0.06 

Krupp uhde—low-temperature catalytic 

reduction method 

$2.92 7% 0.06 0.06 

ECN—low-temperature selective catalytic 

reduction with propane addition 

$5.81 7% 0.06 0.06 

NSCRc $4.03 6% 0.05 0.05 

Adipic Acid Sectorc

Thermal destruction $0.50 50% 0.21 0.24 

Source: USEPA, 2003. Adapted from Nitric Acid and Adipic Acid Sector technology tables in Appendix B. 

a Values represent average percentages across all EMF-21 countries/regions included in the analysis. 

b Based on 10-year lifetime. 

c Based on 20-year lifetime. 

IV.1.3.1 Nitric Acid: N2O Abatement Option Opportunities 

High-Temperature Catalytic Reduction Method 

This N2O abatement option has several variations developed by different companies, all involving 

the decomposition of N2O into nitrogen and oxygen using various catalysts. The average estimated 

reduction efficiency is approximately 90 percent. Total capital costs for these abatement technologies 

range from $2.18 to $3.27 per tCO2eq. Operating and maintenance (O&M) costs vary by country. In the 

United States, O&M costs can range from $0.14 to $0.22 per tCO2eq. This abatement option has an 

average technical lifetime of 10 years, yielding a breakeven price of approximately $0.82 per tCO2eq. 

Low-Temperature Catalytic Reduction Method 

Low-temperature catalytic reduction systems work similarly to high-temperature counterparts but do 

not require heat to decompose the N2O. This abatement option has a reduction efficiency of 95 percent. 

Some versions of this abatement option require propane be added to the gas stream before undergoing 

the reaction process. Total capital cost for this option ranges from $3.27 to $3.55 per tCO2eq. In the United 

States, O&M costs range from $0.27 to $1.91 per tCO2eq. This option has a technical lifetime of 10 years, 

yielding a breakeven price of approximately $0.82 per tCO2eq. 
SECTION IV — INDUSTRIAL PROCESSES x NITRIC AND ADIPIC ACID PRODUCTION 

IV-8 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

Nonselective Catalytic Reduction 

NSCR uses a fuel and a catalyst to consume free oxygen in the tail gas, converting nitrogen oxides to 

elemental nitrogen. The gas from the nitrogen oxides abatement is passed through a gas expander for 

energy recovery, resulting in a reduction efficiency of 85 percent. The process requires additional fuel and 

emits CO2. The total capital cost for this option is $6.27 per tCO2eq. In the United States, the O&M cost is 

estimated at $0.16 per tCO2eq. NSCR has a technical lifetime of 20 years, yielding a breakeven price of 

approximately $1.90 per tCO2eq.

IV.1.3.2 Adipic Acid: N2O Abatement Option Opportunities 

Thermal Destruction 

Thermal destruction is the destruction of off-gases in boilers using reducing flame burners with 

premixed CH4 (or natural gas). The system eliminates between 98 percent and 99 percent of N2O and 

operates from 95 percent to 99 percent of the time. Total capital costs for thermal destruction are $0.38 per 

tCO2eq. In the United States, O&M costs are estimated to be approximately $0.16 per tCO2eq. This 

abatement option has a technical lifetime of 20 years, yielding a breakeven price of approximately $0.27 

per tCO2eq.

IV.1.4 Results 

This section presents the EMF-21’s MAC analysis results. 

IV.1.4.1 Data Tables and Graphs 

The nitric and adipic baselines are presented in Tables 1-6 and 1-8. Tables 1-7 and 1-9 present 

percentage reductions for different carbon prices ($/tCO2eq) from the emissions baselines for each sector. 

Figures 1-2 and 1-3 present these results in graphical form. Significant abatement potential is estimated to 

exist at $15 per tCO2eq. It is estimated that there are no “no-regret” options for N2O nitric or adipic acid 

production. At a breakeven price of $15 per tCO2eq, the percentage abatement is 89 percent for nitric acid 

and 96 percent for adipic acid, reflecting the relatively high technical potential and low abatement cost for 

options in these industrial processes. Technology changes have not been incorporated in the abatement 

potential for N2O emissions from industrial processes. 

IV.1.4.2 Uncertainties and Limitations 

Uncertainties and limitations persist despite attempts to incorporate all publicly available 

information on international sectors. Limited information on the systems of developing countries 

increases this uncertainty. Additional information would improve the accuracy of baseline emissions 

projections.

Improved Cost Data 

Improved documentation of N2O abatement options and their cost components would improve the 

analyst’s ability to estimate baseline reductions given some estimate of market penetration. 

Improved Manufacturing Data for Nitric Acid 

Currently, worldwide nitric acid production is very uncertain because of a lack of good production 

estimates. In addition, improved data on the types of equipment generally employed by industries and 

trends in technology adoption in each country would improve the analyst’s ability to estimate baseline 

emissions over time. 
SECTION IV — INDUSTRIAL PROCESSES • NITRIC AND ADIPIC ACID PRODUCTION 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES IV-9

Table 1-6: Projected N2O Emissions from Nitric Acid by Region: 2000–2020 (MtCO2eq) 

Country/Region 2000 2010 2020 

Africa 1.9 1.9 1.8 

Annex I 68.0 68.5 71.9 

Australia/New Zealand 0.0 0.0 0.0 

Brazil 3.4 4.0 4.3 

China 20.1 22.1 23.7 

Eastern Europe 9.9 9.4 9.7 

EU-15 33.8 36.2 37.3 

India 2.0 2.2 2.4 

Japan 2.8 3.0 3.2 

Mexico 0.6 0.7 0.8 

Non-OECD Annex I 6.6 6.5 6.8 

OECD 66.8 68.4 72.0 

Russian Federation 0.2 0.2 0.2 

South & SE Asia 0.5 0.5 0.6 

United States 17.1 15.5 17.4 

World Total 102.6 107.0 113.1 

Source: USEPA, 2006. 

EU-15 = European Union; OECD = Organisation for Economic Co-operation and Development. 

Table 1-7: Percentage Abatement for Nitric Acid for Selected Breakeven Prices ($/tCO2eq): 2010–2020 

2010 2020 

Country/Region $0 $15 $30 $45 $60 $0 $15 $30 $45 $60 

Africa 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 

Australia/New Zealand 0.00% 88.94% 88.94% 88.94% 88.94% 0.00% 88.94% 88.94% 88.94% 88.94% 

Brazil 0.00% 88.94% 88.94% 88.94% 88.94% 0.00% 88.94% 88.94% 88.94% 88.94% 

China 0.00% 88.94% 88.94% 88.94% 88.94% 0.00% 88.94% 88.94% 88.94% 88.94% 

Eastern Europe 0.00% 88.94% 88.94% 88.94% 88.94% 0.00% 88.94% 88.94% 88.94% 88.94% 

EU-15 0.00% 88.94% 88.94% 88.94% 88.94% 0.00% 88.94% 88.94% 88.94% 88.94% 

India 0.00% 88.94% 88.94% 88.94% 88.94% 0.00% 88.94% 88.94% 88.94% 88.94% 

Japan 0.00% 88.94% 88.94% 88.94% 88.94% 0.00% 88.94% 88.94% 88.94% 88.94% 

Mexico 0.00% 88.94% 88.94% 88.94% 88.94% 0.00% 88.94% 88.94% 88.94% 88.94% 

Russian Federation 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 

South & SE Asia 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 

United States 0.00% 88.94% 88.94% 88.94% 88.94% 0.00% 88.94% 88.94% 88.94% 88.94% 

World Total 0.00% 88.94% 88.94% 88.94% 88.94% 0.00% 88.94% 88.94% 88.94% 88.94% 

Source: USEPA, 2003. Adapted from Nitric Acid Sector technology tables in Appendix B. 

EU-15 = European Union; OECD = Organisation for Economic Co-operation and Development. 
SECTION IV — INDUSTRIAL PROCESSES • NITRIC AND ADIPIC ACID PRODUCTION 

IV-10 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

Table 1-8: Projected N2O Emissions from Adipic Acid by Region: 2000–2020 (MtCO2eq) 

Country/Region 2000 2010 2020 

Africa 1.0 1.0 1.0 

Annex I 34.1 36.9 40.3 

Australia/New Zealand 0.0 0.0 0.0 

Brazil 1.7 2.1 2.4 

China 10.0 11.9 13.3 

Eastern Europe 5.0 5.0 5.4 

EU-15 16.9 19.5 20.9 

India 1.0 1.2 1.4 

Japan 1.4 1.6 1.8 

Mexico 0.3 0.4 0.4 

Non-OECD Annex I 3.3 3.5 3.8 

OECD 33.5 36.8 40.4 

Russian Federation 0.1 0.1 0.1 

South & SE Asia 0.2 0.3 0.3 

United States 8.6 8.4 9.8 

World Total 51.4 57.6 63.5 

Source: USEPA, 2006. 

EU-15 = European Union; OECD = Organisation for Economic Co-operation and Development. 

Table 1-9: Percentage Abatement for Adipic Acid for Selected Breakeven Prices ($/tCO2eq): 2010–2020 

2010 2020 

Country/Region $0 $15 $30 $45 $60 $0 $15 $30 $45 $60 

Africa 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 

Australia/New 

Zealand 

0.00% 96.00% 96.00% 96.00% 96.00% 0.00% 96.00% 96.00% 96.00% 96.00% 

Brazil 0.00% 96.00% 96.00% 96.00% 96.00% 0.00% 96.00% 96.00% 96.00% 96.00% 

China 0.00% 96.00% 96.00% 96.00% 96.00% 0.00% 96.00% 96.00% 96.00% 96.00% 

Eastern Europe 0.00% 96.00% 96.00% 96.00% 96.00% 0.00% 96.00% 96.00% 96.00% 96.00% 

EU-15 0.00% 96.00% 96.00% 96.00% 96.00% 0.00% 96.00% 96.00% 96.00% 96.00% 

India 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 

Japan 0.00% 96.00% 96.00% 96.00% 96.00% 0.00% 96.00% 96.00% 96.00% 96.00% 

Mexico 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 

Russian Federation 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 

South & SE Asia 0.00% 96.00% 96.00% 96.00% 96.00% 0.00% 96.00% 96.00% 96.00% 96.00% 

United States 0.00% 96.00% 96.00% 96.00% 96.00% 0.00% 96.00% 96.00% 96.00% 96.00% 

World Total 0.00% 96.00% 96.00% 96.00% 96.00% 0.00% 96.00% 96.00% 96.00% 96.00% 

Source: USEPA, 2003. Adapted from Nitric Acid Sector technology tables in Appendix B. 

EU-15 = European Union; OECD = Organisation for Economic Co-operation and Development. 
SECTION IV — INDUSTRIAL PROCESSES • NITRIC AND ADIPIC ACID PRODUCTION 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES IV-11

Figure 1-2: EMF MACs for Top Five Emitting Country/Regions from Nitric Acid Production: 2020 

EU-15 = European Union. 

Figure 1-3: EMF MACs for Top Five Emitting Country/Regions from Adipic Acid Production: 2020 

EU-15 = European Union. 
SECTION IV — INDUSTRIAL PROCESSES x NITRIC AND ADIPIC ACID PRODUCTION 

IV-12 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

Improved Emissions Factor Estimates 

Current emissions factors are the result of laboratory experiments and only a few on-site facility 

measurements. Additional facility measurements would greatly improve the accuracy of each country’s 

baseline emissions.

IV.1.5 Summary 

Adipic acid producers in the United States have already adopted options to mitigate emissions of 

N2O. Nitric and adipic acid production will continue to increase, correlating closely with the world’s 

demand for synthetic fertilizers and nylon. However, certain abatement options may mitigate significant 

portions of a country’s baseline if adopted by producers. 

IV.1.6 References 

Chemical Week (CW). 2003. “Adipic Acid.” Chemical Week. April 23, 2003. pg. 25. 

Intergovernmental Panel on Climate Change (IPCC). 1996. Revised 1996 IPCC Guidelines for National 

Greenhouse Gas Inventories: Reference Manual (Volume 3). Available at <http://www.ipccnggip.iges.or.jp/public/gl/invs6.htm>. As obtained on April 26, 2004. 

Intergovernmental Panel on Climate Change (IPCC). 2000. Good Practice Guidance and Uncertainty 

Management in National Greenhouse Gas Inventories. Intergovernmental Panel on Climate Change, 

National Greenhouse Gas Inventories Programme, Montreal, IPCC-XVI/DOC. 10 (1.IV.2000). 

Available at <http://www.ipcc-nggip.iges.or.jp/public/gpglulucf/gpglulucf.htm>. As obtained on 

January 10, 2005. 

Mainhardt, H. and D. Kruger. 2000. “N2O Emissions from Adipic Acid and Nitric Acid Production.” Good 

Practice and Uncertainty Management in National Greenhouse Gas Inventories. Intergovernmental Panel 

on Climate Change, National Greenhouse Gas Inventories Programme, Montreal, IPCC-XVI/DOC. 10 

(1.IV.2000). Available at <http://www.ipcc-nggip.iges.or.jp/public/gpglulucf/gpglulucf.htm>. 

Smit, A.W., M.M.C. Gent, and R.W. van den Brink. 2001. Market Analysis DeN20: Market Potential For 

Reduction of N2O Emissions at Nitric Acid Facilities. Leiden, Netherlands: Jacobs Engineering 

Nederland. 

U.S. Environmental Protection Agency (USEPA). 2001. “U.S. Adipic Acid and Nitric Acid N2O Emissions 

1990–2020: Inventories, Projections and Opportunities for Reductions.” Washington, DC: USEPA. 

U.S. Environmental Protection Agency (USEPA). 2003. International Analysis of Methane and Nitrous Oxide 

Abatement Opportunities. Report to Energy Modeling Forum, Working Group 21. Appendices 

“Nitrous Oxide Baselines.” Washington, DC: USEPA. Available at <http://www.epa.gov/methane/ 

appendices.html>. As obtained on March 25, 2005. 

U.S. Environmental Protection Agency (USEPA). 2004. Inventory of U.S. Greenhouse Gas Emissions and Sinks 

1990–2002. FRL-05-3794. Washington, DC: USEPA, Office of Solid Waste and Emergency Response. 

Available at <http://yosemite.epa.gov/oar/globalwarming.nsf/content/ResourceCenterPublications 

GHGEmissionsUSEmissionsInventory2005.html>. As obtained on March 24, 2005. 

U.S. Environmental Protection Agency (USEPA). 2006. Global Anthropogenic Non-CO2 Greenhouse Gas 

Emissions: 1990–2020. Washington, DC: USEPA. 
SECTION IV — INDUSTRIAL PROCESSES • NITRIC AND ADIPIC ACID PRODUCTION 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES IV-13

Explanatory Notes 

1. Separate emissions estimates for nitric and adipic acid were unavailable for 2005, thus projected 

percentage changes are presented for 2000 to 2020. Note that individual percentage changes for nitric 

and adipic acid are not comparable with the total percentage change of 16 percent, which is for 2005 

to 2020. 
SECTION IV — INDUSTRIAL PROCESSES • NITRIC AND ADIPIC ACID PRODUCTION 

IV-14 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 
SECTION IV — INDUSTRIAL PROCESSES • REFRIGERATION AND AIR-CONDITIONING 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES IV-15

IV.2 HFC Emissions from Refrigeration and Air-Conditioning 

IV.2.1 Introduction 

 number of HFCs are used in refrigeration and air-conditioning systems and are emitted to 

the atmosphere during equipment operation and repair. Specifically, emissions occur during 

product and equipment manufacturing and servicing, and from disposal of equipment and 

used refrigerant containers. Emissions also occur during equipment operation, as a result of component 

failure, leaks, and purges. The use of refrigeration and air-conditioning equipment also generates indirect 

emissions of greenhouse gases (primarily CO2) from the generation of power required to operate the 

equipment. In some refrigeration and air-conditioning applications, these indirect emissions outweigh the 

direct emissions. Therefore, energy efficiency has a major impact on the total greenhouse gas emissions of 

an application. To the extent possible, both direct and indirect emissions were considered in the 

refrigeration and air-conditioning analysis; however, options aimed solely at improving energy efficiency 

rather than abating HFC emissions were not explored in detail. HFCs used in this sector have 100-year 

GWPs that range from 140 to 11,700; the majority of HFCs used today in the refrigeration and airconditioning sector have GWPs from 1,300 (i.e., HFC-134a) to 3,300 (i.e., R-507A). 

The refrigeration and air-conditioning sector includes eight major end-uses: 

• household refrigeration, 

• motor vehicle air-conditioning (MVAC), 

• chillers, 

• retail food refrigeration, 

• cold storage warehouses, 

• refrigerated transport, 

• industrial process refrigeration, and 

• residential and small commercial air-conditioning/heat pumps. 

Each end-use is composed of a variety of equipment types that have historically used ODSs such as 

chlorofluorocarbons (CFCs) or hydrochlorofluorocarbons (HCFCs). As the ODS phaseout is taking effect 

under the Montreal Protocol, equipment is being retrofitted or replaced to use HFC-based substitutes or 

intermediate substitutes (e.g., HCFCs) that will eventually need to be replaced by non–ozone-depleting 

alternatives. HCFCs are beginning to be replaced with HFCs or other alternative refrigerants. The eight 

major end-uses are explained in more detail below. 

IV.2.1.1 Household Refrigeration 

This end-use consists of household refrigerators and freezers. HFC-134a is the primary substitute for 

CFC-12 in domestic refrigeration units in the United States and most developing countries, with 

hydrocarbon (HC) refrigerant, especially isobutane (HC-600a), dominating much of the European market 

and continuing to grow in market share. HC-600a is also gaining market share in Japan (Kuijpers, 2002). 

The charge size of a typical household refrigeration unit in the United States has decreased over the past 

15 years to about 0.17 kilograms for new HFC-134a units, with sizes even smaller in Europe.1 HC-600a 

 

1 Differences in charge sizes are accounted for in the modeling methodology. 

A 
SECTION IV — INDUSTRIAL PROCESSES • REFRIGERATION AND AIR-CONDITIONING 

IV-16 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

systems are about 40 percent smaller than HFC-134a systems. The equipment has an expected lifetime of 

20 years. This end-use is one of the largest in terms of the number of units in use; however, because the 

charge sizes are small and the units are hermetically sealed (and, therefore, rarely require recharging), 

emissions are relatively low. Thus, the potential for reducing emissions through leak repair is small. In 

most Annex I countries, where regulations are in place that require the recovery of refrigerant from 

appliances prior to disposal, the retirement of old refrigerators is not expected to result in significant 

refrigerant emissions. Refrigerant emissions at disposal from developing countries, where refrigerant 

recovery is not generally required, are expected to be greater. Emissions from the insulating foam in 

household refrigerators and freezers are discussed in a separate chapter of this report. 

IV.2.1.2 Motor Vehicle Air-Conditioning (MVAC) 

This end-use includes the air-conditioning systems in motor vehicles (e.g., cars, trucks, and buses). 

Currently, the quantity of refrigerant contained in a typical car air conditioner is approximately 1 

kilogram—generally from 1 to 1.2 kilograms for vehicles containing CFC-12 systems, and an average of 

approximately 0.8 kilograms for vehicles containing HFC-134a systems (Atkinson, 2000; European 

Commission [EC], 2003)—although this varies by car and region (e.g., in Japan, the average amount is 

about 0.5 kilograms). Because of concerns over the environmental impact of refrigerants, the average 

charge size of MVACs—as well as associated leak rates—have been reduced over time; this trend is 

expected to continue. The expected lifetime of MVACs is approximately 12 years. Refrigerant use in this 

sector is significant because more than 700 million motor are vehicles registered globally (Ward’s, 2001). 

In developed countries, CFC-12 was used in MVACs until being phased out of new cars in 1992 through 

1994. Since then, all air conditioners installed in new automobiles use HFC-134a refrigerant. HFC-134a is 

also used as a retrofit chemical for existing CFC-12 systems (UNEP, 1998). 

CFC-12 availability in developing countries and in some developed countries (e.g., the United States) 

has resulted in its use for servicing older MVACs that were originally manufactured as CFC-12 systems. 

A variety of refrigerant blends are approved for use in the United States by the USEPA as replacements 

for CFC-12 in MVACs. However, these blends have not been endorsed by vehicle or system 

manufacturers. Globally, these blends have captured only a small and declining share of the retrofit 

market. Some conversions from CFC-12 to pure HCs have been done. However, this is illegal in the 

United States, and such use in direct expansion systems not designed for a flammable refrigerant can 

pose safety concerns and is not considered acceptable by much of the global MVAC industry. Climate 

change concerns associated with the use of HFC-134a resulted in research into and development of other 

MVAC alternatives. Possible alternatives to HFC-134a systems include transcritical CO2 systems, 

hydrocarbons (e.g., in new secondary-loop systems), and HFC-152a systems, all of which are under study 

and development (SAE, 2003a). 

IV.2.1.3 Chillers 

Chillers are used to regulate the temperature and reduce humidity in offices, hotels, shopping 

centers, and other large buildings, as well as in specialty applications on ships, submarines, nuclear 

power plants, and other industrial applications. The four primary types of chillers are centrifugal, 

reciprocating, scroll, and screw, each of which is named for the type of compressor employed. Chillers 

last longer than most air-conditioning and refrigeration equipment. The majority of operating chillers will 

remain in service for more than 20 years, and some will last 30 years or more. A wide variety of chillers is 

available, with cooling capacities from 7 kilowatts to over 30,000 kilowatts (RTOC, 2003). The charge size 

of a chiller depends mostly on cooling capacity and ranges from less than 25 kilograms (reciprocating) to 

over 2,000 kilograms (centrifugal). HCFC-123 has been the refrigerant of choice as a retrofit option for 

newer CFC-11 units, and HFC-134a has been the refrigerant of choice as a retrofit option for newer CFC-
SECTION IV — INDUSTRIAL PROCESSES • REFRIGERATION AND AIR-CONDITIONING 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES IV-17

12 units. The replacement market for CFC-12 high-pressure chillers and CFC-11 low-pressure chillers is 

dominated by both HCFC-123 chillers and HFC-134a chillers in developed and developing countries. 

Following phaseout of the production of HCFCs (in 2030 for developed countries and 2040 for 

developing countries), recycled, recovered, and reclaimed HCFCs will continue to be used in most 

countries. This trend is not the case, however, in the European Union (EU-25), where there are restrictions 

on the use of HCFCs in new equipment, the production of HCFCs is not permitted beyond 2010, and 

recycled HCFCs may not be reused beyond 2015. In the EU, HFC-134a will be an important option for 

chillers, but because of its global warming impact, ammonia chillers are being used as an alternative in 

some countries (Kuijpers, 2002). 

Additionally, HFC-245fa is a potential refrigerant for new low-pressure chillers. However, for a 

variety of reasons, the commercialization of this chiller technology is not likely to occur in the near future, 

if at all. High-pressure chillers that currently use HCFC-22 will ultimately be replaced by several HFC 

refrigerant blends and HFC-134a chillers. Likewise, existing CFC-114 chillers have been converted to 

HFC-236fa or replaced with HFC-134a chillers, for use primarily in specialty applications (e.g., on ships 

and submarines, and in nuclear power plants) (RTOC, 2003; IPCC/TEAP, 2005). 

IV.2.1.4 Retail Food Refrigeration 

Retail food refrigeration includes refrigerated equipment found in supermarkets, convenience stores, 

restaurants, and other food service establishments. This equipment includes small refrigerators and 

freezers, refrigerated display cases, walk-in coolers and freezers, and large parallel systems. Charge sizes 

range from 6 to 1,800 kilograms, with a lifetime of about 15 years. Convenience stores and restaurants 

typically use standalone refrigerators, freezers, and walk-in coolers. In contrast, supermarkets usually 

employ large parallel systems that connect many display cases to a central compressor rack and 

condensing unit by means of extensive piping. Because the connection piping can be miles long, these 

systems contain very large refrigerant charges and often experience high leakage rates. 

During the earlier phases of the CFC phaseout in developed countries, the use of HCFC-22 in retail 

food refrigeration was expanded considerably. Retail food equipment is being retrofitted with HCFCbased blends, although HFC blends are also used as a retrofit refrigerant. The HFC blend R-404A is the 

preferred refrigerant in new retail food equipment in developed countries, while R-507A is also used 

extensively in the market (Kuijpers, 2002). In developed countries, both distributed and centralized 

systems that use HFCs, HCs, ammonia, and CO2 are being developed (both with and without secondary 

loops) (Kuijpers, 2002). 

IV.2.1.5 Cold Storage Warehouses 

Cold storage warehouses are used to store meat, produce, dairy products, and other perishable 

goods. The expected lifetime of a cold storage warehouse is 20 to 25 years, and although charge sizes vary 

widely with system size and design, a rough average is about 4,000 kilograms. Warehouses in developed 

countries have historically used CFC-12 and R-502 refrigerants and currently use HCFC-22, R-404A, and 

R-507A. The latter two refrigerants are expected to replace HCFC-22 in new warehouses. Retrofits are 

also possible; for example, existing CFC-12 cold storage warehouses can be retrofitted with R-401A, and 

existing R-502 warehouses can be retrofitted with R-402A. Not all cold storage warehouses use 

halocarbon refrigerants. Many facilities, for example, use ammonia in secondary loop brine systems.

IV.2.1.6 Refrigerated Transport 

The refrigerated transport end-use includes refrigerated ship holds, truck trailers, railway freight 

cars, refrigerated rigid vans/trucks, and other shipping containers. Although charge sizes vary greatly, 
SECTION IV — INDUSTRIAL PROCESSES • REFRIGERATION AND AIR-CONDITIONING 

IV-18 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

the average charge sizes are relatively small (7 to 8 kilograms). The expected lifetime of a refrigerated 

transport system is 12 years. Trailers, railway cars, and shipping containers using CFC-substitute 

refrigerants are commonly charged with HFC-134a, R-404A, and HCFC-22 (UNEP, 1999a). Ship holds, on 

the other hand, rely on HCFC-22 (UNEP, 1999a) and ammonia. In addition to HFC-134a, R-404A can be 

used in new equipment. Existing equipment can be retrofitted with R-401A, R-402A, R-404A, R-507A, and 

other refrigerants. In addition, refrigerated transport equipment includes systems that operate based on 

the evaporation and expansion of liquid CO2 or nitrogen. 

IV.2.1.7 Industrial Process Refrigeration 

Industrial process refrigeration includes complex, often custom-designed refrigeration systems used 

in the chemical, petrochemical, food processing, pharmaceutical, oil and gas, and metallurgical 

industries; in sports and leisure facilities; and in many other applications. Charge sizes typically range 

from 650 to 9,100 kilograms, and the average lifetime is approximately 25 years. Ammonia, HCs, HCFC123, and HFC-134a are expected to be the most widely used substitute refrigerants for new equipment in 

the near future (UNEP, 1999a). Upon completion of the HCFC phaseout, HFC-134a, R-404A, and R-507A 

are expected to be the primary refrigerants used in this end-use. 

IV.2.1.8 Residential and Small Commercial Air-Conditioning and Heat Pumps 

Residential and small commercial air-conditioning (e.g., window units, unitary air conditioners, and 

packaged terminal air conditioners) and heat pumps are another source of HFC emissions. Most of these 

units are window and through-the-wall units, ducted central air conditioners, and nonducted split 

systems. The charge sizes of the equipment in this sector range from 0.5 to 10 kilograms for residential 

systems, and about 10 to 180 kilograms for commercial systems based on cooling capacity requirements. 

The average lifetime of this type of equipment is 15 years. Residential and commercial air-conditioning 

has been relying almost exclusively on HCFC-22 refrigerant. R-410A, R-407C, and HFC-134a are currently 

used to replace HCFC-22 in some new equipment for most end-uses, and this trend is expected to 

continue as HCFC-22 is phased out. In particular, R-410A is expected to dominate the U.S. residential 

market in the future, whereas R-407C is expected to replace HCFC-22 in retrofit applications and some 

new residential and commercial equipment. Other countries may experience different patterns of R-410A 

and R-407C use. 

IV.2.2 Baseline Emissions Estimates 

IV.2.2.1 Emissions Estimating Methodology 

Description of Methodology 

Specific information on how the model calculates refrigeration and air-conditioning emissions is 

described below. 

The USEPA’s Vintaging Model and industry data were used to simulate the aggregate impacts of the 

ODS phaseout on the use and emissions of various fluorocarbons and their substitutes in the United 

States. Emissions estimates for non-U.S. countries incorporated estimates of the consumption of ODSs by 

country, as provided by the United Nations Environment Programme (UNEP, 1999b). The estimates for 

EU-15 were provided in aggregate, and each country’s gross domestic product (GDP) was used as a 

proxy to divide the consumption of the individual member nations by the EU-15 total. Estimates of 

country-specific ODS consumption, as reported under the Montreal Protocol, were then used in 

conjunction with Vintaging Model output for each ODS-consuming sector. In the absence of country-level 

data, preliminary estimates of emissions were calculated by assuming that the transition from ODSs to 
SECTION IV — INDUSTRIAL PROCESSES • REFRIGERATION AND AIR-CONDITIONING 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES IV-19

HFCs and other substitutes follows the same general substitution patterns internationally as observed in 

the United States. From this preliminary assumption, emissions estimates were then tailored to 

individual countries or regions by applying adjustment factors to U.S. substitution scenarios, based on 

relative differences in (1) economic growth; (2) rates of ODS phaseout; and (3) the distribution of ODS use 

across end-uses in each region or country, as explained below. 

Emissions Equations 

For refrigeration and air-conditioning products, emissions calculations were split into two categories: 

emissions during equipment lifetime, which arise from annual leakage and service losses, and disposal 

emissions, which occur at the time of discard. The first equation calculates the emissions from leakage 

and service, and the second equation calculates the emissions resulting from disposal of the equipment. 

These service, leakage, and disposal emissions were added to calculate the total emissions from 

refrigeration and air-conditioning. As new technologies replace older ones, improvements in their 

leakage, service, and disposal emissions rates were assumed to occur. 

Emissions from any piece of equipment include both the amount of chemical leaked during 

equipment operation and the amount emitted during service. Emissions from leakage and servicing can 

be expressed as follows: 

Esj = (la + ls) × ̕ Qcj-i+1 for I = 1 → k (2.1) 

where 

Es = Emissions from equipment serviced. Emissions in year j from normal leakage and 

servicing of equipment. 

la = Annual leakage rate. Average annual leakage rate during normal equipment operation, 

expressed as a percentage of total chemical charge. 

ls = Service leakage rate. Average annual leakage from equipment servicing, expressed as a 

percentage of total chemical charge. 

Qc = Quantity of chemical in new equipment. Total amount of a specific chemical used to 

charge new equipment in a given year, by weight. 

j = Year of emissions. 

i = Counter. From 1 to lifetime (k). 

k = Lifetime. The average lifetime of the equipment. 

Note: It is recognized that leakage rates are not a function of the total system, but change with system 

pressure and temperature. For instance, when equipment charges are diminished because of refrigerant 

losses (i.e., leakage), system pressures are also reduced somewhat and the leakage rate changes. This 

change becomes appreciable once the entire liquid refrigerant is gone. The average leakage rates used in 

the equation above were intended to account for this effect. The rates also accounted for the range of 

equipment types (from those that do not leak at all to those with high leaks) and service practices (i.e., 

proper refrigerant recovery and refrigerant venting). 

Emissions also occur during equipment disposal. The disposal emissions equations assumed that a 

certain percentage of the chemical charge will be emitted to the atmosphere when that vintage is 

discarded. Disposal emissions are thus a function of the quantity of chemical contained in the retiring 

equipment fleet and the proportion of chemical released at disposal: 
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IV-20 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

Edj = Qcj-k+1 × [1 – (rm × rc)] (2.2) 

where 

Ed = Emissions from equipment disposed. Emissions in year j from the disposal of equipment. 

Qc = Quantity of chemical in new equipment. Total amount of a specific chemical used to 

charge new equipment one lifetime (k) ago, by weight. 

rm = Chemical remaining. Amount of chemical remaining in equipment at the time of disposal, 

expressed as a percentage of total chemical charge. 

rc = Chemical recovery rate. Amount of chemical that is recovered just prior to disposal, 

expressed as a percentage of chemical remaining at disposal (rm). 

j = Year of emissions. 

i = Counter. From 1 to lifetime (k). 

k = Lifetime. The average lifetime of the equipment. 

Finally, lifetime and disposal emissions were summed to provide an estimate of total emissions: 

Ej = Esj + Edj (2.3) 

where 

E = Total emissions. Emissions from refrigeration and air-conditioning equipment in year j. 

Es = Emissions from equipment serviced. Emissions in a given year from normal leakage and 

servicing (recharging) of equipment. 

Ed = Emissions from equipment disposed. Emissions in a given year from the disposal of 

equipment. 

j = Year of emissions. 

Regional Variations and Adjustments 

From the general methodology, the following regional assumptions were applied: 

• Adjustment for Regulation (EC) No 2037/2000. Countries in the EU-15 were assumed to be in 

full compliance with Regulation (EC) No 2037/2000, which stipulates that no new refrigeration 

and air-conditioning equipment should be manufactured with HCFCs, as of January 1, 2002.2

 The 

European Commission (EC) regulation also bans the use of HCFCs for servicing equipment after 

January 1, 2015. Compliance with these regulations will likely lead to increased use of HFCs to 

replace HCFCs. These changes were assumed to correspond to increased emissions of 20 percent 

in 2005, 15 percent in 2010, and 15 percent in 2020, relative to what the EU-15 baseline otherwise 

would be. These relative emissions increases were determined by running a Vintaging Model 

scenario where the uses of HCFCs were assumed to comply with the regulation. No adjustments 

for Regulation (EC) No 2037/2000 were made to the 10 countries that joined the EU in March 

2004, as this analysis was conducted prior to this date. 

 

2 The ban was delayed until July 1, 2002, for fixed air-conditioning equipment with a cooling capacity of less than 100 

kW and until January 1, 2004, for reversible air-conditioning/heat pump systems. 
SECTION IV — INDUSTRIAL PROCESSES • REFRIGERATION AND AIR-CONDITIONING 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES IV-21

• Recovery and Recycling Adjustments. For developing (i.e., non-Annex I) countries, countries 

with economies in transition (CEITs), and Turkey, the emissions were increased by 

approximately 20 percent over initial estimates to reflect the assumed low levels of recovery and 

recycling of refrigerants from small end-uses (i.e., MVACs, commercial and residential airconditioning, refrigerated transport, and other appliances), relative to the United States. This 

assumed increase in emissions from lower levels of recovery and recycling was based on an 

analysis of a variety of scenarios using the Vintaging Model, where emissions were first projected 

assuming an 80-percent baseline recovery rate to reflect the assumed status quo in developed 

countries and then projected again assuming a 30-percent baseline recovery rate to reflect the 

assumed status quo in developing countries. The GWP-weighted emissions in the latter lowrecovery scenario were determined to be approximately 20 percent higher than in the former 

high-recovery scenario (ICF Consulting, 2002a). 

• Market Adjustments. The baseline assumes that HC and ammonia refrigerants and other nonHFC or low-emitting options will penetrate international markets more than the United States 

market because of differences in safety standards; greater acceptance of non-HFC choices by 

industry, end-users, regulators, and insurance companies; and increased public and regulatory 

scrutiny to reduce HFC emissions. To reflect this penetration, baseline emissions estimates of 

non-U.S. countries were reduced by the following amounts (Table 2-1). 

Table 2-1: Reductions in Baseline Emissions in Non-U.S. Countries to Reflect Market Adjustments 

Country/Region Percent 

EU-15 30a

Japan 30 

Non-EU-15 Europe 20a

CEITs 20 

Australia/New Zealand 10 

All other countries 20 

EU-15 = European Union; CEITs = countries with economies in transition. 

a The new EC Directive on MVACs, which bans the use of HFC-134a in new vehicle models in 2011 and in all vehicles in 2017, was not 

considered in developing these baseline emissions adjustments for EU countries, as the directive was not finalized at the time this analysis 

was conducted. 

 These assumptions were based solely on qualitative information on current and future global 

market penetration of low-GWP refrigerants, as well as low-emission technologies and practices. 

For example, HC technology is believed to dominate the domestic refrigeration market in 

Western Europe, particularly in Germany and Scandinavia. HC domestic refrigerators are 

produced by major manufacturers in Germany, Denmark, Italy, Japan, United Kingdom, France, 

Spain, and Sweden. Some of the largest manufacturers in China, India, Indonesia, Australia, 

Korea, and Cuba are also producing domestic refrigerators that use HCs (Greenpeace, 2001; 

Japan Times, 2002). To reflect this and many other trends, baseline emissions from non-U.S. 

countries were adjusted downward, as shown above. 

• Redistribution of Emissions by End-Use, Based on MVAC Analysis. Based on a variety of 

available data on international motor vehicle sales, air-conditioning usage, and MVAC emissions, 

a separate analysis was conducted to estimate total MVAC emissions by region. These MVAC 

emissions estimates by region were then used to determine the relative share of refrigeration and 

air-conditioning emissions attributable to MVACs and to reapportion emissions from all other 

end-uses accordingly, relative to the end-use breakout calculated for the United States. The 

methodology used to perform this analysis is explained in detail below. 
SECTION IV — INDUSTRIAL PROCESSES • REFRIGERATION AND AIR-CONDITIONING 

IV-22 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

MVAC Analysis

The Vintaging Model estimates MVAC emissions for the United States based on vehicle sales data, 

assumptions on the percentage of vehicles with functional air-conditioning, and a projected growth rate 

of 2.6 percent (based on sales data from 1970 through 2001). Table 2-2 presents the Vintaging Model’s 

estimated percentage of baseline refrigeration and air-conditioning emissions attributable to MVACs in 

the United States from 2005 through 2020. 

Table 2-2: Estimated Percentage of GWP-Weighted Refrigeration and Air-Conditioning HFC Emissions 

Attributable to MVACs in the United States 

2005 2010 2015 2020 

Percent 35.9 27.6 22.6 19.9 

However, because the market penetration of air-conditioning into vehicles is assumed to be different 

in other countries and regions,3 and because MVACs are assumed to account for a different proportion of 

total refrigeration and air-conditioning emissions in the United States compared with most other 

developed and developing countries, this end-use has been modeled separately to achieve a higher 

degree of accuracy in emissions estimates. To this end, for all countries for which data on MVACs or 

historical vehicle sales were available, country-specific MVAC models were developed to estimate the 

total number of MVACs in past, present, and future years. Ward’s World Motor Vehicle Data (2001), the 

Society of Indian Automobile Manufacturers (SIAM) (2005), and the China Association of Automobile 

Manufacturers (2005) were used as data sources. 

The remainder of this section describes the assumptions and data used to project the number of 

MVACs by country and region. It should be noted that, while the MVAC industry is investigating new 

refrigerants and other emissions reduction initiatives (see http://www.epa.gov/cppd/mac/), these actions 

are not considered in the baseline estimates. 

India 

India’s MVAC fleet estimates were developed based on (1) data on MVAC sales prior to 2004, from 

SIAM (2005), (2) projected annual growth rates of new vehicle sales, and (3) projected annual growth 

rates of air-conditioning penetration. Specifically, India’s future vehicle fleet growth was assumed to be 8 

percent per year,4

 while air-conditioning penetration was assumed to increase linearly to reach 95 percent 

in 2010.5

 Beyond 2010, it was assumed that air-conditioning penetration will be maintained at 95 percent 

because vehicle air-conditioning will become standard. The assumed air-conditioning market penetration 

rates for India are summarized in Table 2-3. 

Table 2-3: Percentage of Newly Manufactured Vehicles Assumed to Have Operational Air-Conditioning Units 

in India 

2005 2010 2015 2020 

Percent 92.5 95 95 95 

 

3 Except for Japan, which is assumed to have the same market penetration rate of MVACs into new vehicles as the 

United States. 

4 This growth rate was based on the annual growth rate of passenger vehicles (assumed to be linear) between 2000 

and 2004, with the fleet size in 2000 based on Ward’s (2001) and the fleet size in 2004 based on SIAM (2005). 

5 Air-conditioning penetration was grown from 92 percent in 2004, based on data from SIAM (2005). 
SECTION IV — INDUSTRIAL PROCESSES • REFRIGERATION AND AIR-CONDITIONING 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES IV-23

China 

MVAC estimates for China are based on data on Chinese production of vehicles with air-conditioning 

from 1994 to 2004, provided by the China Association of Automobile Manufacturers (2005). Projections of 

future MVACs in China were based on the assumed growth rate of India’s vehicle market beyond 2005 

(assumed to be 8 percent per year, as described above).6 The same assumptions were applied to Hong 

Kong. 

All Other Countries 

For all countries other than the United States, Japan, India, China, and Hong Kong, the number of 

operational MVACs was estimated based on (1) annual historical sales of passenger cars and light trucks, 

as provided in Ward’s (2001), and (2) estimates of the percentage of the vehicle fleet equipped with airconditioning, based on quantitative and qualitative data provided in EC (2003); Hill and Atkinson (2003); 

OPROZ (2001); and Barbusse, Clodic, and Roumegoux (1998), as presented in Table 2-4. 

Table 2-4: Percentage of Newly Manufactured Vehicles Assumed to Have Operational Air-Conditioning Units 

in All Other Countries 

Country/Region 2005 2010 2015 2020 

All other Annex I countries 65.5 70.0 80.5 95.0 

Latin America and Caribbean 50.0 55.0 60.0 65.0 

All other non-Annex I countries, Russian 

Federation, and Ukraine 

23.0 28.0 33.0 38.0 

As shown above, MVACs were assumed to increasingly penetrate the vehicle fleet over time. In the 

developing countries that were modeled, this rate of increase was assumed to be 1 percent each year, 

while in all other Annex I countries, the rate of increase was assumed to be more rapid, reaching 95 

percent of the vehicle fleet in 2020 (EC, 2003; Hill and Atkinson, 2003). 

Once the MVAC fleet was estimated by country/region, annual MVAC emissions were calculated 

assuming annual average leak and service emissions of 10.9 percent.7 MVAC emissions at disposal were 

assumed to be 42.5 percent of the original MVAC charge in developed countries and 69 percent in 

developing countries (as a result of zero recovery assumed).8 All systems were assumed to use HFC-134a 

refrigerant in the baseline. The new EC Directive on MVACs9 was not considered in the baseline 

estimates, as this directive was not finalized at the time this analysis was conducted. 

 

6 India’s projected growth rate was selected for use in place of China’s historical growth rate because China’s 

historical growth rate (of approximately 25%) was considered unrealistically high to maintain for 2.5 decades. 

7 This emissions rate includes emissions released during routine equipment operation from leaks, as well as those 

released during the servicing of equipment by both professionals and do-it-yourselfers. 

8 This percentage (69 percent) is the implied loss at disposal given the assumption that twice the original MVAC 

charge is emitted over the course of a vehicle’s lifetime in developing countries. 

9 In April 2006, the European Parliament adopted a legislative resolution on the joint text approved by the 

Conciliation Committee for a directive of the European Parliament and of the Council relating to emissions from air 

conditioning systems in motor vehicles and amending Council Directive 70/156/EEC. The directive places a ban on 

the use of fluorinated gases with a GWP of more than 150 in new vehicle models planned from 2011 onwards, and in 

all vehicles from 2017 onwards. 
SECTION IV — INDUSTRIAL PROCESSES • REFRIGERATION AND AIR-CONDITIONING 

IV-24 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

Once MVAC emissions were estimated by country/region, the proportion of MVAC emissions as a 

percentage of the total refrigeration and air-conditioning emissions (developed using the methodology 

described above) was calculated. These percentages were then averaged by region. The average estimated 

percentage of refrigeration and air-conditioning GWP-weighted emissions that are attributable to 

MVACs by regional grouping are presented in Table 2-5. 

Table 2-5: Estimated Percentage of Refrigeration and Air-Conditioning HFC Emissions Attributable to MVACs 

Country/Region 2005 2010 2015 2020 

United States and Japan 35.9 27.6 22.6 19.9 

All other Annex I countries 46.9 42.8 31.8 36.6 

China, Hong Kong, and India 41.3 53.0 62.0 65.8 

Latin America and Caribbean 14.2 13.3 12.6 12.0 

Russian Federation, Ukraine, and all other nonAnnex I countries 3.8 3.8 5.4 8.0 

Based on the above percentage of sector baseline emissions assumed to come from MVACs for each 

region, for lack of reliable data to suggest otherwise, the U.S. baseline emissions breakout by end-use was 

used to proportionally redistribute the remaining emissions of a particular country/region. For example, 

because MVACs contributed only 14.2 percent of total sector emissions in Latin American countries in 

2005, the balance of emissions in Latin America was distributed across all other end-uses, in proportion to 

the U.S. end-use breakout. The resulting subdivision of baseline GWP-weighted HFC emissions by enduse and region are summarized in Table 2-6. These emissions subdivisions by end-use help determine the 

maximum amount of emissions that can be avoided by any given abatement option, because each option 

is applicable only to specific end-uses. 

IV.2.2.2 Baseline Emissions 

The amount of HFC emissions from MVAC units is expected to rise, because HFC-134a has been the 

primary refrigerant used in the growing automobile industry, and because HFC-134a is the primary 

refrigerant used to replace older CFC-12 systems. The baseline for MVACs assumes a mix of 

professionally serviced systems and those serviced by people without recovery equipment. Because 

commercial unitary and residential air-conditioning equipment has yet to transition fully into HFCs, the 

emissions of HFCs from these end-uses in 2005 were estimated to be relatively insignificant, but will 

increase substantially over time. Retail food systems are expected to (and in many cases, already have)

transition at least partially to HFC-134a and HFC-containing blends because of certain equipment 

characteristics (such as their large number of fittings); such systems may have higher refrigerant 

emissions rates. Cold storage systems also have large charge sizes, but their emissions relative to other 

refrigeration and air-conditioning end-uses are not expected to increase significantly. HFC emissions 

from chillers are relatively low as a result of the continued use of HCFC-123 in this application,10 as well 

as the low leakage rates of new HFC-134a units. The baseline emissions projections assumed that the 

recovery and recycling of refrigerants during service and disposal in Annex I countries will curtail 

emissions across all end-uses. 

 

10 Note that emissions of all CFC and HCFC refrigerants, including HCFC-123, were not included in the baseline 

emissions estimates. 
SECTION IV — INDUSTRIAL PROCESSES • REFRIGERATION AND AIR-CONDITIONING 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES IV-25

The resulting baseline estimates of HFC emissions are summarized in Table 2-7 and Figure 2-1 in 

million metric tons of carbon dioxide equivalents (MtCO2eq). 

IV.2.3 Cost of HFC Emissions Reduction from Refrigeration and AirConditioning 

This section presents a cost analysis for achieving HFC emissions reductions from the emissions 

baselines presented above. Each abatement option is described below, but only those options not 

assumed to occur in the baseline and for which adequate cost data are available were included in the cost 

analysis. To the extent possible, this analysis considered total equivalent warming impacts (TEWI)11 to 

account for the climate and cost impacts of energy consumption (i.e., indirect emissions). Because of data 

limitations, a full life cycle analysis was not possible. For example, the cost and emissions impacts 

associated with (1) the manufacture of refrigerant and all system components, (2) the energy required for 

reclamation, and (3) the recycling of all system components at the end of equipment life were not 

assessed in this analysis. 

The remainder of this section describes the economic assumptions for these abatement options. 

IV.2.3.1 Description and Cost Analysis of Abatement Options 

HFC emissions from refrigeration and air-conditioning equipment can be reduced through a variety 

of practice and technology options. Many of the options considered in this report would require 

voluntary action by the private sector or further government regulation. For example, national 

governments can regulate maximum allowable leakage rates for refrigeration and air-conditioning 

equipment and/or require the recovery of refrigerant and the proper disposal of nonreclaimable 

refrigerant. Many Annex I countries have already implemented a variety of such regulatory actions to 

reduce ODS emissions. Some of the most widely recognized options to reduce refrigerant emissions are 

listed below (UNEP, 1998; UNEP, 1999a; Crawford, 1999; USEPA, 2001a). 

Practice Options 

• leak repair 

• refrigerant recovery and recycling 

• proper refrigerant disposal 

• technician certification and HFC sales restriction 

Alternative Refrigerant Options 

• ammonia 

• HCs 

• CO2

• other low-GWP refrigerants 

 

11 TEWI is the combined effects of direct greenhouse gas impacts (i.e., chemical emissions) and indirect greenhouse 

gas impacts (i.e., energy-related CO2 emissions). 
SECTION IV — INDUSTRIAL PROCESSES • REFRIGERATION AND AIR-CONDITIONING 

IV-26 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

Table 2-6: Distribution of Refrigeration- and Air-Conditioning–Sector HFC Emissions by End-Use, Region, 

and Year (Percent) 

End-Use 

United 

States and 

Japan 

All Other 

Annex I 

Countries 

Latin 

America and 

Caribbean 

China, 

Hong Kong, 

and India 

All Other NonAnnex I Countries, 

Russian Federation, 

and Ukraine 

2005

Chillers 3.2 2.7 4.3 3.0 4.8 

Retail food 39.0 32.3 52.2 35.7 58.4 

Cold storage 1.2 1.0 1.6 1.1 1.8 

Industrial process 4.6 3.8 6.1 4.2 6.8 

Commercial air-conditioning 1.1 0.9 1.4 1.0 1.6 

Residential air-conditioning 0.6 0.5 0.8 0.6 0.9 

Refrigerated transport 14.0 11.6 18.8 12.8 21.0 

Other appliancesa 0.5 0.4 0.6 0.4 0.7 

MVACs 35.9 46.9 14.2 41.3 3.8 

2010

Chillers 2.3 1.8 2.8 1.5 3.1 

Retail food 41.7 33.0 50.0 27.0 55.4 

Cold storage 1.4 1.1 1.7 0.9 1.9 

Industrial process 6.0 4.8 7.2 3.9 8.0 

Commercial air-conditioning 5.3 4.2 6.3 4.3 7.0 

Residential air-conditioning 5.5 4.4 6.6 3.6 7.4 

Refrigerated transport 9.7 7.7 11.6 6.3 12.9 

Other appliancesa 0.4 0.3 0.5 0.3 0.6 

MVACs 27.6 42.8 13.3 53.2 3.8 

2015

Chillers 1.8 1.6 2.0 0.9 2.2 

Retail food 41.2 36.3 46.5 20.2 50.3 

Cold storage 1.4 1.2 1.6 0.7 1.7 

Industrial process 6.4 5.6 7.2 3.1 7.8 

Commercial air-conditioning 8.8 7.8 10.0 4.3 10.8 

Residential air-conditioning 9.7 8.5 10.9 4.7 11.8 

Refrigerated transport 7.2 6.3 8.1 3.5 8.7 

Other appliancesa 1.0 0.9 1.1 0.5 1.2 

MVACs 22.6 31.8 12.6 62.0 5.4 

2020

Chillers 1.5 1.2 1.6 0.6 1.7 

Retail food 39.1 31.0 43.0 16.7 44.9 

Cold storage 1.4 1.1 1.6 0.6 1.6 

Industrial process 6.6 5.2 7.3 2.8 7.6 

Commercial air-conditioning 11.3 8.9 12.4 4.8 12.9 

Residential air-conditioning 13.3 10.5 14.6 5.7 15.2 

Refrigerated transport 6.1 4.9 6.7 2.6 7.0 

Other appliancesa 0.8 0.6 0.9 0.3 0.9 

MVACs 19.9 36.6 12.0 65.8 8.0 

Note: Totals may not sum because of independent rounding. 

a Other appliances include refrigerated appliances, dehumidifiers, and ice makers. 
SECTION IV — INDUSTRIAL PROCESSES • REFRIGERATION AND AIR-CONDITIONING 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES IV-27

Table 2-7: Total Baseline HFC Emissions from Refrigeration and Air-Conditioning (MtCO2eq) 

Region 2000 2010 2020 

Africa 2.8 12.8 20.4 

Annex I 95.1 244.9 414.4 

Australia/New Zealand 1.3 3.2 5.6 

Brazil 1.5 6.9 12.0 

China 4.1 25.8 61.7 

Eastern Europe 0.9 4.2 7.3 

EU-15 13.3 37.9 58.4 

India 0.5 2.6 5.4 

Japan 16.4 32.6 45.1 

Mexico 1.4 6.6 11.2 

Non-OECD Annex I 1.8 9.3 17.3 

OECD 98.5 260.8 441.4 

Russian Federation 1.3 6.9 13.4 

South & SE Asia 2.9 14.7 28.1 

United States 58.0 148.6 264.6 

World Total 117.0 356.4 627.3 

EU-15 = European Union; OECD = Organisation for Economic Co-operation and Development. 

Figure 2-1: Baseline HFC Emissions from Refrigeration and Air-Conditioning by Region (MtCO2eq) 

CPA = Centrally Planned Asia; Non-EU FSU = non-European Union Former Soviet Union countries; OECD90+ = Organisation for Economic 

Co-operation and Development. 
SECTION IV — INDUSTRIAL PROCESSES • REFRIGERATION AND AIR-CONDITIONING 

IV-28 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

Technology Options 

• distributed systems12 for stationary commercial refrigeration equipment 

• secondary loop systems for stationary equipment, including HFC secondary loop systems and 

ammonia secondary loop systems 

• enhanced HFC-134a systems in MVACs 

• HFC-152a refrigerant in MVACs (direct expansion or secondary loop systems) 

• CO2 systems in MVACs 

• oil-free compressors 

• geothermal (in lieu of air-to-air) cooling systems 

• desiccant cooling systems 

• absorption systems 

Table 2-8 summarizes the duration and applicability of the process and technology emissions 

reduction options across all end-use applications considered in this analysis. The applicability of the 

alternative refrigerant options depends on the technology used; hence, some options were explored in 

more detail in the analysis of technology options. Consideration of distribution costs associated with the 

technology options was not included in the analysis. All costs are presented in 2000 dollars. 

The following section describes all of these options in greater detail and presents a cost analysis for 

those options not assumed to occur in the baseline and for which adequate cost data were available. The 

resulting emissions abatement potentials and costs of each option explored in the cost analysis are 

summarized in Section IV.2.4. The technology options explored in this chapter do not include retrofit 

costs and, therefore, were assumed to penetrate only the markets of new (not existing) equipment. New 

equipment is defined as air-conditioning and refrigeration equipment manufactured in 2005 or later. 

Detailed descriptions of the cost and emissions reduction analysis for each option can be found in 

Appendix F for this chapter. 

 

12 The term distributed system, as used in this report, refers to commercial refrigeration equipment used in retail 

food and cold storage applications, although the term could also refer to equipment used in other applications, such 

as residential and small commercial air-conditioning. 
SECTION IV — INDUSTRIAL PROCESSES • REFRIGERATION AND AIR-CONDITIONING 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES IV-29 Table 2-8: Assumptions on Duration and Applicability of Emissions Reduction Options Potential Applicability to End-Use Equipment Option Description Duration of Emissions Reduction (Years) Chillers Retail Food Cold Storage Ware- houses Refrigerated Transport Industrial Process Refrig- eration Commercial Air- Conditioning MVACs Residential Air- Conditioning Household Refrigeration and Small Appliances Practice Options Leak repair 5 3

3

3  3    

Refrigerant recovery 1    3  3

3

3

3

Proper refrigerant disposal NA         Technician certification NA         Alternative RefrigerantsAmmonia Lifetime of equipment  3

3  

HCs Lifetime of equipment         CO2 Lifetime of equipment       3  Other low-GWP refrigerants Lifetime of equipment       3  Technology OptionsDistributed systems for stationary 

commercial refrigeration equipment 

Lifetime of equipment 

3

3

Secondary loop systems for stationary 

equipment—HFC primary refrigerant 

Lifetime of equipment 

3

3 

Secondary loops systems for stationary 

equipment—ammonia primary refrigerant 

Lifetime of equipment 

3

3 

Enhanced HFC-134a systems in 

MVACs 

Lifetime of equipment 

3

HFC-152a in MVACs (direct expansion 

or secondary loop) 

Lifetime of equipment 

3

CO2 in MVACs Lifetime of equipment 

3

Oil-free compressors Lifetime of equipment         Geothermal (in lieu of air-to-air) cooling 

systems 

Lifetime of equipment  

Desiccant cooling systems Lifetime of equipment   Absorption systems Lifetime of equipment   

NA: Not applicable. 3 Option is technically feasible and was addressed in the cost analysis of this report.  Option is potentially feasible but was not addressed in the cost analysis of this report, either because it is current practice (assumed to occur in the baseline) or because insufficient information was 

available to include it in the cost analysis. 
SECTION IV — INDUSTRIAL PROCESSES • REFRIGERATION AND AIR-CONDITIONING 

IV-30 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

Practice Options 

Four practice options are discussed in this section—leak repair, refrigerant recovery, proper 

refrigerant disposal, and technician certification. Together with additional measures (including designing 

and installing equipment to minimize HFC emissions), these practices are often considered standard 

good practices and are identified in a number of different responsible use guides—such as that published 

by the Alliance for Responsible Atmospheric Policy (ARAP) (see http://www.arap.org/ 

responsible.html)—and endorsed through voluntary industry partnerships, including those initiated by 

the USEPA (see http://www.epa.gov/ozone/snap/emissions/index.html). However, this report assumes 

that there are opportunities to further apply these options to reduce emissions from the baseline prepared 

for this report. 

Leak Repair for Large Equipment

Reducing leakage rates can significantly reduce HFC emissions, especially in systems such as chillers, 

cold storage warehouses, and retail food systems that can leak large amounts of refrigerant. Although 

some of the options available may be impractical for existing equipment, given the difficulty and expense 

of retrofitting, there are still many options that are economically feasible. Some of the leak repair options 

used in current industry practice include 

• use of preventive maintenance, including scheduled inspection and repairs; 

• monitoring of leaks using stationary leak monitors or other new technologies, such as early 

warning signals,13 remote monitoring, and diagnostics; 

• use of new, more durable gasket materials that provide tighter seals and absorb less refrigerant; 

• augmentation of threaded joints with ʅ-ring seals; 

• augmentation or replacement of gaskets and ʅ-rings with adhesive sealants; 

• broader use and improvement of brazing techniques rather than threaded or snap fittings (e.g., 

use of sufficient silver content14 and use of dry nitrogen or other inert gas to avoid oxidation); 

• focus on ensuring accessibility to field joints and use of isolation valves, which allows for greater 

ease of repair; 

• focus on proper securing to reduce vibration fractures in the pipe and connections from the 

compressor and other moving parts of the system; 

• repair or retrofit of high-emitting systems through targeted component upgrades;15 and 

• performance of major modifications to the systems (USEPA, 1997; USEPA, 1998; Calm, 1999).16

 

13 Technologies in the final stages of development are expected to generate early warning signals at less than 5 

percent charge loss in commercial refrigeration and air-conditioning systems (Gaslok, 2002). 

14 For solder, a 15-percent silver content is recommended (USEPA, 1997). 

15 This option may include replacing the purge unit or other component upgrades that typically require the removal 

of refrigerant from the machine, 2 full days of two technicians’ time, and several thousand dollars’ worth of materials 

(USEPA, 1998). 
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GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES IV-31

As suggested by the above list, leak reduction options range from simple repairs to major system 

upgrades. Even in countries where maximum allowable leakage rates are regulated by law, further leak 

reduction improvements, such as the replacement or upgrade of a major system component, are still 

possible. For example, preliminary data gathered from U.S. industry indicate that leakage rates for certain 

types of existing equipment in the United States range from 8 to 40 percent, whereas achievable leakage 

rates for new or modified equipment range from 4 to 15 percent. According to the Intergovernmental 

Panel on Climate Change/Technology and Economic Assessment Panel (IPCC/TEAP), studies have 

reported global annual refrigerant loss from supermarket refrigeration systems to range from 3.2 percent 

in the Netherlands to 22 percent in the United States (IPCC/TEAP, 2005). For this same type of 

equipment, the International Energy Agency (IEA) estimates that historical leakage rates have been 30 

percent or higher, whereas newer systems can achieve leakage rates of approximately 15 percent or 

slightly lower (IEA, 2003). Some newer retail food equipment has reached leakage rates of less than 10 

percent (Crawford, 2002). 

Since the lower-cost leak reduction options represent significant cost savings, this analysis assumes 

that the leak reductions occur under the baseline. The cost analysis therefore focused only on the more 

extensive and costly options. This option was assumed to be technically applicable17 to all equipment 

with large charge sizes (i.e., chillers, retail food refrigeration, cold storage, and industrial process 

refrigeration). This analysis assumed that 50 percent of emissions occur as a result of equipment leakage 

during routine operation, while the other 50 percent of emissions are released during equipment 

servicing and disposal. Thus, the maximum technical applicability of this option was assumed to be 50 

percent of emissions from large equipment (see Table 2-9). Furthermore, this analysis assumed that leak 

repair can reduce annual system leakage by 40 percent, using an example of a supermarket system that 

leaks at 25 percent annually but only at 15 percent following repairs. The project lifetime was assumed to 

be 1 year. Regional technical applicability for 2010 and 2020 and reduction efficiency are presented in 

Table 2-9. Assumptions on maximum market penetration for each region and year are presented in 

Table 2-19. 

Refrigerant Recovery and Recycling from Small Equipment

Recovery and recycling of HFCs help to decrease HFC emissions during equipment service and 

disposal. The approach involves the use of a refrigerant recovery device that transfers refrigerant into an 

external storage container prior to servicing of the equipment. Once the recovery process and source 

operations are complete, the refrigerant contained in the storage container may be recharged back into 

the equipment, cleaned through the use of recycling devices, sent to a reclamation facility to be purified,18

or disposed of through the use of incineration technologies. Refrigerant recovery may also be an 

 

16 This option may include modifications that are not strictly leak repair, but would result in greatly reduced leakage 

rates. For example, combining the installation of a new purge system, the replacement of flare joints, and other 

containment options, or combining the replacement of gaskets and seals, replacement of the motor, and installation 

of new refrigerant metering. 

17 In this report, the terms “technically applicable” and “technical applicability” refer to the emissions to which an 

option can theoretically be applied. The leak repair option was assumed to be technically applicable to all emissions 

from leaks (but not servicing and disposal) from the four end-uses listed in Table 2-9. 

18 Recycling cleans and reclamation purifies recovered refrigerant; reclamation is more thorough and involves 

repeated precision distillation, filtering, and contaminant removal. Recycling is used for on-site servicing of MVACs 

and other equipment, and reclamation requires sending the refrigerant off-site to a reclaimer. 
SECTION IV — INDUSTRIAL PROCESSES • REFRIGERATION AND AIR-CONDITIONING 

IV-32 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

Table 2-9: Summary of Assumptions for Leak Repair for Large Equipment 

Technical Applicabilityb

Country/Region 

Applicable 

End-Usesa

Reduction 

Efficiencya 2010 2020 

United States and Japan 25.7% 24.3% 

Other Annex I countries 20.3% 19.3% 

Latin America and Caribbean 30.8% 26.7% 

China, Hong Kong, and India 16.7% 10.4% 

Other non-Annex I countries, Russian 

Federation, and Ukraine 

Chillers 

Retail food 

Cold storage 

Industrial process 

40.0% 

34.2% 27.9% 

a End-uses and reduction efficiency apply to all regions. 

b Technical applicability is shown as a percentage of total refrigeration- and air-conditioning-sector emissions and equals 50 percent of total 

refrigeration and air-conditioning emissions from chillers, retail food refrigeration, cold storage, and industrial process refrigeration. See 

Section IV.2.4 for a more complete explanation of how technical applicability, reduction efficiency, and market penetration were used to 

calculate emissions reductions associated with each option. 

important way to reduce emissions from near-empty refrigerant containers (i.e., can heels). Refrigerant 

recovery is assumed to be widely practiced in Annex I countries in the baseline, where the procedure is 

typically required by law. 

This analysis assesses only the recovery of refrigerant from small equipment (i.e., MVACs, 

refrigerated transport, household and other small appliances, and unitary equipment) above that which is 

already practiced (e.g., recovery due to regulations in many developed countries or for economic reasons) 

at service and disposal. It is assumed that recovery from large equipment is already widely practiced in 

the baseline19 because of the significant cost savings associated with recovery of large quantities of 

refrigerant from this equipment. Because emissions reductions and costs vary by scenario and end-use, 

emissions reductions and costs associated with four recovery scenarios were averaged to obtain one 

breakeven cost. The four scenarios studied were recovery and recycling of refrigerant from (1) MVACs at 

service, (2) MVACs at disposal, (3) small appliances at service, and (4) small appliances at disposal. 

This analysis assumed that 50 percent of emissions are released during equipment servicing and 

disposal, while the remaining 50 percent occur as a result of leakage during normal operations. Thus, the 

technical applicability20 of this option is 50 percent of emissions from small equipment (see Table 2-10). 

Furthermore, because in the United States small appliances are considered completely recovered when 90 

percent of the refrigerant is removed from units with running compressors, or when 80 percent of the 

refrigerant is removed from units with nonoperating compressors, this analysis assumed that the 

reduction efficiency of this option is 85 percent (Contracting Business Interactive, 2003; USEPA, 1993). 

The project lifetime is assumed to be 1 year. Regional technical applicability for 2010 and 2020 and 

reduction efficiency are presented in Table 2-10. Recovery from small appliances and MVACs was 

 

19 Although the Society of Automotive Engineers (SAE) has issued industry standards on equipment and technician 

procedures that apply to MVACs and provide for on-site recovery and recycling of HFC-134a from MVAC systems 

for reuse in the serviced system, recovery from these and other small systems is still not believed to be widely 

practiced in most developing countries as a result of a lack of infrastructure (i.e., recovery and recycling equipment) 

(World Bank, 2002). 

20 In this report, the terms “technically applicable” and “technical applicability” refer to the emissions to which an 

option can theoretically be applied. The refrigerant recovery and recycling option was assumed to be technically 

applicable to all emissions during servicing and disposal (but not leaks) from the five end-uses listed in Table 2-10. 
SECTION IV — INDUSTRIAL PROCESSES • REFRIGERATION AND AIR-CONDITIONING 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES IV-33

Table 2-10: Summary of Assumptions for Recovery and Recycling from Small Equipment 

Technical 

Applicabilityb

Country/Region Applicable End-Usesa

Reduction 

Efficiencya 2010 2020 

United States and Japan 24.3% 25.7% 

Other Annex I countries 29.7% 30.7% 

Latin America and Caribbean 19.2% 23.3% 

China, Hong Kong, and India 33.3% 39.6% 

Other non-Annex I countries, Russian 

Federation, and Ukraine 

MVAC 

Refrigerated transport 

Household and other small appliances 

Commercial unitary air-conditioning 

Residential air-conditioning 

85.0% 

15.8% 22.1% 

a End-uses and reduction efficiency apply to all regions. 

b Technical applicability is shown as a percentage of total refrigeration- and air-conditioning-sector emissions and equals 50 percent of total 

refrigeration and air-conditioning emissions from MVACs, refrigerated transport, household and other small appliances, and commercial 

unitary and residential air-conditioning. 

assumed to be practiced at 80 percent in the baseline in developed countries and at 30 percent in the 

baseline in developing countries. Assumptions on maximum market penetration for each region and year 

are presented in Table 2-19. 

Proper Refrigerant Disposal

One potential source of emissions from the refrigeration and air-conditioning sector is the accidental 

or deliberate venting of refrigerant. The venting of refrigerant can be reduced by increasing the 

reclamation of used refrigerant (discussed in more detail below) and properly disposing of refrigerant 

that cannot be reclaimed (such as highly contaminated refrigerant or mixed refrigerant). Disposal costs 

vary by country and region, as do transportation costs, storage costs, and access to refrigerant disposal 

facilities (e.g., high-temperature incinerators that handle refrigerants). Global average ODS destruction 

costs are estimated to vary between $1.70 and $2.60 per pound (approximately $4 to $6 per kilogram) (ICF 

Consulting, 2002b). This option was not explored in the cost analysis as a result of the uncertainty 

associated with access to disposal facilities and cost disparities within regions. 

Technician Certification and HFC Sales Restriction

By ensuring that refrigeration and air-conditioning technicians receive training in proper refrigerant 

handling, including recovery and recycling practices, or by restricting the sale of HFC refrigerants to 

certified technicians only, refrigerant emissions can be reduced. In some countries, including the United 

States, technicians must be certified in accordance with national regulations to purchase CFC and HCFC 

refrigerants and service refrigeration and air-conditioning equipment. Restricting the use of HFC 

refrigerants to certified technicians would similarly reduce emissions. To the extent that technician 

certification and HFC sales restrictions are practiced today, these actions were included in the baseline; 

additional implementation of these practices was not explored in this analysis due to uncertainty in cost 

and emissions reductions. 

Alternative Refrigerant Options 

This section describes four alternative refrigerants: ammonia, hydrocarbons, carbon dioxide, and 

other low-GWP refrigerants. 
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IV-34 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

Ammonia

Ammonia, primarily used in water-cooled chillers, has excellent thermodynamic properties and can 

be used in many types of systems. Because ammonia has a strong odor, refrigerant leaks are easier to 

detect, and because ammonia is lighter than air, dispersion is facilitated in the event of a release (UNEP, 

1999a). However, ammonia must be used carefully because it is toxic and slightly flammable. Ammonia is 

an explosion hazard at 16 to 25 percent in air, which creates a problem in confined spaces. Chillers that 

use ammonia as a refrigerant are commercially available in Europe and elsewhere, and they have 

efficiencies that are comparable to those of HFC-134a chillers in some instances. Building and fire codes, 

however, restrict the use of ammonia in urban areas of the United States and in many other countries. 

These safety concerns and institutional barriers effectively limit the potential for expanded use of 

ammonia chillers (Sand, Fischer, and Baxter, 1997). 

Whereas the use of ammonia within public spaces, such as supermarkets, is limited in some countries 

by building codes and ordinances, ammonia is a potential alternative for supermarkets if safety concerns 

can be adequately addressed through engineering design such as secondary loops and isolation. Indeed, 

modern ammonia systems manufactured in the United States are fully contained, closed-loop systems 

with fully integrated controls that regulate pressures throughout the system. Also, all systems are 

required to have an emergency diffusion system and a series of safety relief valves to protect the system 

and its pressure vessels from overpressurization and possible failure (ASHRAE, 2002). Systems with 

ammonia are being built and used in Europe (Sand et al, 1997). However, the further use of ammonia as a 

supermarket primary refrigerant may be unlikely in the near future in the United Kingdom and other 

countries because of the capital costs and issues of compliance with standards and safety regulations 

(Cooper, 1997). Ammonia would also be an option in some industrial process refrigeration and cold 

storage applications, contingent upon addressing all of the relevant concerns regarding flammability and 

toxicity. For example, ammonia is used in about 80 percent of current installations of large-size 

refrigeration plants, as well as in many indirect commercial refrigeration systems (RTOC, 2003). 

The chemical properties of ammonia make it incompatible with current designs of light residential 

and commercial unitary air-conditioning systems, which use copper for the refrigerant tubing, in the heat 

exchangers, and in other components. In the presence of water, ammonia cannot be used with copper or 

zinc (UNEP, 1999a); however, ammonia can be used in aluminum and steel systems. Compatible 

components would need to be developed to use ammonia. As a result of these technical and cost barriers, 

as well as ammonia’s flammability and toxicity, ammonia is considered an unlikely candidate for use in 

commercial and residential unitary equipment (Sand et al., 1997). 

Many of the existing uses of ammonia were included in the baseline analysis. One additional 

option—using ammonia secondary loop systems in retail food and cold storage end-uses—is analyzed in 

more detail in the section on “Technology Options” that follows this section on alternative refrigerant 

options. 

HCs

HCs have thermodynamic properties comparable to fluorocarbons that make them good refrigerants; 

however, the high flammability of HCs causes safety concerns. Considering technical requirements alone, 

there is potential for use of HCs in retail food refrigeration, refrigerated transport, household 

refrigeration, residential air-conditioning, MVACs, and commercial unitary systems. Currently used 

refrigerants include HC-600a, HC-290, and HC-1270 (UNEP, 1999a). In addition to good thermodynamic 

properties, HCs have other advantages such as energy efficiencies comparable to fluorocarbons, zero 

ozone depletion potential (ODP), and very low direct GWP. 
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GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES IV-35

The primary disadvantage of HCs is their flammability, resulting in significant safety and liability 

issues. These concerns cause increased costs for safety precautions in factories and can necessitate design 

changes in every application, such as relocation of electrical components to reduce the likelihood of 

accidents from potential leaks (Kruse, 1996; Paul, 1996). These concerns also entail additional hardware 

costs for many applications (ADL, 1999; Crawford, 2000). HC refrigerant use is generally restricted by 

U.S. safety codes, and with the exception of industrial refrigeration, the USEPA has not listed HCs as 

acceptable substitutes to ODS refrigerants (per Section 612 of the Clean Air Act Amendments of 1990). 

Even if systems that are designed to use HC refrigerants were listed, liability concerns would remain. 

Systems using flammable refrigerants will require additional engineering and testing, development of 

standards and service procedures, and training of manufacturing and service technicians before 

commercialization. 

HC domestic refrigerators have been available in Western Europe since the early 1990s, and have 

now fully penetrated some of the new domestic refrigeration markets. HC domestic refrigerators are 

available in Argentina, Australia, Brazil, China, Cuba, Germany, India, Indonesia, Japan, and elsewhere. 

Similarly, HC refrigerants are available in other products, although little information is readily available 

regarding their market success to date (Hydro Cool Online, 2002; Calor Gas Refrigeration Web site, 2004; 

CARE Web site, 2004). 

In addition, HCs have been used in MVACs for the last several years. Some have estimated that, in 

certain parts of Australia, 280,000 vehicles contain HC refrigerants (Greenchill Web site, 2000), although 

independent data have not been supplied to confirm this estimate. The use of HC refrigerants in direct 

expansion systems not designed for a flammable refrigerant can pose safety concerns and is not 

considered acceptable by much of the global MVAC industry. The SAE’s Alternate Refrigerant 

Cooperative Research Program has demonstrated a secondary loop system using HC refrigerant that 

minimizes the possible release of flammable refrigerant into the passenger compartment (Hill and 

Atkinson, 2003). 

Proponents of HC systems claim that these systems bring numerous benefits, including increased 

energy efficiency, lower refrigerant cost, lower capital cost, and less noise (HyChill Web site, 2004; 

Greenchill Web site, 2000), but little independent research exists to confirm these claims. In many parts of 

the world, however, safety issues, public perception, and manufacturer acceptance impede further 

penetration of this option. 

This analysis does not consider the use of HCs in household refrigeration because this option was 

assumed to reach maximum market penetration in the baseline. In those regions where HCs have not 

successfully penetrated markets (e.g., North America), the perceived risk and lack of acceptance of HC 

refrigerants, which has prevented adoption to date, was assumed to continue to serve as a barrier in the 

foreseeable future. The use of HCs in other refrigeration end-uses was not considered because of 

uncertainty about costs and likely market penetration. 

CO2

Another option is to use CO2 as a refrigerant. Prototype CO2 systems have been developed for 

numerous types of systems, including MVACs, industrial processing, refrigerated transport, and retail 

food systems. CO2 has zero ODP and a GWP of 1, and is claimed by its proponents to be advantageous 

for use as a refrigerant. However, CO2 is associated with potential safety risks and other technical and 

economic disadvantages. Above certain concentrations, exposure to CO2 may result in adverse health 

consequences. At very high concentrations, even for short periods of time, CO2 affects the central nervous 

system and is toxic. To protect against adverse health effects from workplace exposure, the Occupational 

Safety and Health Administration (OSHA) recommended an 8-hour time-weighted average exposure 
SECTION IV — INDUSTRIAL PROCESSES • REFRIGERATION AND AIR-CONDITIONING 

IV-36 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

limit of 5,000 parts per million (ppm) (ACGIH, 1999). Also, CO2 systems operate at a high pressure, which 

presents a potential hazard and may increase the cost of designing and purchasing equipment. In 

addition, potential loss of operational efficiency and associated increases in energy use and indirect 

emissions, refrigerant containment issues, long-term reliability, and compressor performance are other 

potential problems (Environment Canada, 1998). 

For this analysis, CO2 systems were evaluated only as options for MVACs. CO2 is being investigated 

for other end-uses but, because research is still in the early stage and there is little information, those enduses were not explored in this analysis. The MVAC option is described in detail in the section on 

“Technology Options.” 

Other Low-GWP Refrigerants

The use of other low-GWP refrigerants (e.g., HFC-152a with a GWP of 140) in place of higher-GWP 

refrigerants (e.g., HFC-134a with a GWP of 1,300) is another option for reducing greenhouse gas 

emissions. The use of HFC-152a in MVACs was explored in this cost analysis, as described in detail in the 

“Technology Options” section. 

Several other low-GWP refrigerants exist. For example, CO2, discussed above, has a GWP of 1. In 

addition, HCFC-123 and HCFC-124, which are not considered alternatives to HFCs, have low direct 

GWPs, but their use is complicated by other factors, including their contribution to stratospheric ozone 

depletion. While some studies (e.g., Calm, Wuebbles, and Jain, 1999; Wuebbles and Calm, 1997; USEPA, 

2002; RTOC, 2003) suggest that the extended use of HCFC-123 in large tonnage chillers may reduce direct 

GWP-weighted refrigerant emissions, and in some instances may reduce overall greenhouse gas 

emissions, this option was not examined here because full compliance with the current HCFC phaseout 

schedule was assumed. 

Technology Options 

This section presents cost analyses for six alternative technology options, three of which apply to the 

stationary equipment (distributed systems, HFC secondary loop systems, and ammonia secondary loop 

systems), and three of which apply to mobile systems (enhanced HFC-134a, HFC-152a, and CO2). Oil-free 

compressors, geothermal cooling systems, and desiccant cooling systems are also described qualitatively. 

Distributed Systems for Stationary Commercial Refrigeration Equipment

A distributed system consists of multiple compressors that are distributed throughout a store, near 

the display cases they serve, and are connected by a water loop to a single cooling unit that is located on 

the roof or elsewhere outside the store. Refrigerant charges for distributed systems can be smaller than 

the refrigerant charge used in a comparable traditional centralized direct expansion (DX) system. 

Significant reductions in total global warming impact from current levels may be possible with 

distributed systems that use HFC refrigerants (Sand et al., 1997). 

Using HFC-distributed systems in lieu of HFC centralized DX systems in retail food settings offers 

the potential to reduce HFC emissions. Distributed systems have smaller refrigeration units distributed 

among the refrigerated and frozen food display cases, with each unit sending heat to a central water 

cooling system. A distributed system would significantly reduce the refrigerant inventory—by an 

estimated 75 percent—and minimize the length of refrigerant tubing and the number of fittings that are 

installed in DX systems, thereby reducing HFCs leaks by an estimated 5 percent to 7 percent 

(IPCC/TEAP, 2005). 

This technology option is assumed to be applicable to the retail food and cold storage end-uses. The 

project lifetime is assumed to be 15 years, and the emissions reduction efficiency is calculated to be 90 
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GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES IV-37

percent. Regional technical applicability for 2010 and 2020 and reduction efficiency are presented in 

Table 2-11. Assumptions on maximum market penetration for each region and year are presented in 

Tables 2-18 and 2-19, expressed as a percentage of emissions from new equipment, and as a percentage of 

emissions from all equipment (new and existing), respectively. Because the cost analysis for this option 

does not address the costs to retrofit existing DX systems, this option is assumed to penetrate only new 

retail food and cold storage installations (i.e., those installed in 2005 or beyond). 

Table 2-11: Summary of Assumptions for Distributed Systems for New Stationary Equipment 

Technical Applicabilityb

Country/Region 

Applicable EndUse Sector(s)aReduction 

Efficiencya 2010 2020 

United States and Japan 43.1% 40.6% 

Other Annex I countries 34.1% 32.1% 

Latin America and Caribbean 51.7% 44.5% 

China, Hong Kong, and India 28.0% 17.3% 

Other non-Annex I countries, Russian 

Federation, and Ukraine 

Retail food 

Cold storage 

90.0% 

57.3% 46.6% 

a End-uses and reduction efficiency apply to all regions. 

b Technical applicability is shown as a percentage of total refrigeration and air-conditioning sector emissions and equals the percentage of total 

refrigeration and air-conditioning emissions that are assumed to come from retail food and cold storage end-uses. 

Secondary Loop Systems for Stationary Equipment

Secondary loop systems pump cold fluid to remove heat from equipment (e.g., refrigerated food 

display cases) or areas to be cooled. The fluid, often a brine solution, passes through a heat exchanger to 

be cooled by a refrigerant isolated from the equipment or areas cooled. These systems require a 

significantly lower refrigerant charge, have lower leakage rates, and can allow the use of flammable or 

toxic refrigerants. 

Secondary loops may be used in commercial and industrial refrigeration applications, for example, to 

cool supermarket display cases without circulating toxic or flammable refrigerants throughout the store 

or to reduce the needed charge of HFC refrigerants. The primary disadvantages of the secondary loop 

system are a loss of energy efficiency and higher capital costs. Potential benefits of secondary cooling 

systems, however, include decreased charge sizes, decreased leakage rates, faster defrost, lower 

maintenance needs, and longer shelf lives, which can result in significant cost savings over time (Bennett, 

2000; Baxter, 2003; Faramarzi and Walker, 2003). Indeed, the reduction in size and leakage rate of the 

refrigerant charge could result in a reduced global warming impact, even with the use of fluorocarbon 

refrigerants. The use of zero-GWP refrigerants could result in even lower global warming impacts (Sand, 

et al., 1997). Furthermore, secondary loop systems have improved temperature control compared with 

conventional direct expansion systems, which can represent an important advantage in countries like the 

United States, where recent regulations on temperature control for refrigerated products such as meat, 

poultry, and fish have become more stringent. Moreover, recent technological improvements to 

secondary cooling systems, such as high-efficiency evaporative condensers and display cases with high 

temperature brines, have increased system efficiency (Baxter, 2003; Faramarzi and Walker, 2003). Two 

types of secondary loop systems, for use in retail refrigeration and cold storage warehouses, are analyzed 

in greater detail below. 

Secondary loops could mitigate some but not all of the risks of using flammable refrigerants in 

residential and commercial unitary end-uses. In addition, secondary loops have potential applications in 
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IV-38 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

MVACs, discussed further in “HFC-152a Refrigerant in MVACs.” Because of the lack of technical and 

cost information on secondary loop systems in these other applications, they are not included as options 

in this analysis. 

HFC Secondary Loop Systems for Stationary Commercial Refrigeration Equipment 

Designing new retail food and cold storage systems to operate using secondary loops with HFCs can 

reduce HFC emissions. As discussed above, secondary loop systems circulate a secondary coolant or 

brine from the central refrigeration system to the display cases (UNEP, 1999a; ADL, 1999). These systems 

have lower leakage rates and operate at reduced charges. Additionally, pipes used in these systems are 

now premanufactured and can be made of preinsulated plastic instead of copper. This design reduces 

material costs and, by eliminating the need for brazing, allows for faster installation. In the United States, 

installation costs have been reduced significantly in recent years. With continued research and 

development, this technology is expected to soon be as cost-effective to purchase, install, and operate as 

centralized DX systems (Bennett, 2000). This technology option is assumed to be applicable to the retail 

food and cold storage end-use sectors, and is expected to reduce charge size by between 75 percent and 

85 percent and bring annual leakage rates down to about 5 percent (IPCC/TEAP, 2005)—reducing direct 

emissions from appropriate end-uses by approximately 93 percent (see calculation below). The project 

lifetime is assumed to be 15 years. The regional technical applicabilities for 2010 and 2020 and the 

reduction efficiencies are presented in Table 2-12. Assumptions on maximum market penetration for each 

region and year are presented in Tables 2-18 and 2-19. Because the cost analysis for this option does not 

address the costs to retrofit existing DX systems, this option is assumed to penetrate only new retail food 

and cold storage installations (i.e., those installed in 2005 or beyond). 

Table 2-12: Summary of Assumptions for HFC Secondary Loop Systems for New Stationary Equipment 

Technical Applicabilityb

Country/Region 

Applicable EndUse Sector(s)aReduction 

Efficiencya 2010 2020 

United States and Japan 43.1% 40.6% 

Other Annex I countries 34.1% 32.1% 

Latin America and Caribbean 51.7% 44.5% 

China, Hong Kong, and India 28.0% 17.3% 

Other non-Annex I countries, Russian 

Federation, and Ukraine 

Retail food 

Cold storage 

93.33% 

57.3% 46.6% 

a End-uses and reduction efficiency apply to all regions. 

b Technical applicability is shown as a percentage of total refrigeration and air-conditioning sector emissions and equals the percentage of total 

refrigeration and air-conditioning emissions that are assumed to come from equipment in the retail food and cold storage end-uses. 

Ammonia Secondary Loop Systems for Stationary Commercial Refrigeration Equipment 

The use of ammonia is very common in some countries, while strongly restricted in others. For 

example, for many decades ammonia has been used in almost all dairies, breweries, slaughterhouses, and 

large freezing plants across Europe, while its use has been heavily regulated in North America (ACHR 

News, 2000). Ammonia refrigeration has historically been used in large, low-temperature industrial 

refrigeration, as well as in medium and large chillers, generally for food processing (Crawford, 1999). 

However, the use of ammonia refrigerant is beginning to expand into retail food and smaller chillers in 

some countries, particularly in the EU-15. 

Because of ammonia’s materials capability, toxicity, and flammability, major design modifications 

would be required for the majority of traditional HFC systems. Furthermore, since different countries 
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GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES IV-39

have different sets of building codes, fire codes, and other safety standards relating to the use of ammonia 

in building equipment, some countries (e.g., the United States) would need to revise those codes to allow 

for the expanded use of ammonia in new equipment types. 

Ammonia can be used as the primary refrigerant in secondary loop systems in place of HFCs. 

Because ammonia secondary loop systems avoid running the primary refrigerant through miles of piping 

to and from food storage cases, they have lower leakage rates than conventional centralized DX systems 

and operate at reduced charges. In these types of systems, ammonia is kept out of public contact (e.g., 

outside of buildings), and nontoxic fluids are used as secondary coolants. Incremental one-time costs for 

ammonia systems are assumed to include expenditures for equipment needed to ensure safety. The 

annual operating costs also include net energy requirements, but, because of a lack of information, do not 

cover costs associated with training technicians and development and updating of safety protocols to 

handle more hazardous refrigerants, including ammonia. This technology option is assumed to be 

applicable to the retail food and cold storage end-uses. The project lifetime is assumed to be 15 years. The 

reduction efficiency of this option is 100 percent, as the ammonia completely replaces the HFC. Because 

the cost analysis for this option does not address the costs to retrofit existing DX systems, this option is 

assumed to be technically applicable in only new (i.e., those installed in 2005 or beyond) retail food and 

cold storage installations. 

Table 2-13 presents the reduction efficiency and regional technical applicabilities for 2010 and 2020. 

Table 2-13: Summary of Assumptions for Ammonia Secondary Loop Systems for New Stationary Equipment 

Technical Applicabilityb

Country/Region 

Applicable EndUse Sector(s)aReduction 

Efficiencya 2010 2020 

United States and Japan 43.1% 40.6% 

Other Annex I countries 34.1% 32.1% 

Latin America and Caribbean 51.7% 44.5% 

China, Hong Kong, and India 28.0% 17.3% 

Other non-Annex I countries, Russian 

Federation, and Ukraine 

Retail food 

Cold storage 

100.0% 

57.3% 46.6% 

a End-uses and reduction efficiency apply to all regions. 

b Technical applicability is shown as a percentage of total refrigeration and air-conditioning sector emissions and equals the percentage of total 

refrigeration and air-conditioning emissions that are assumed to come from equipment in the retail food and cold storage end-uses. 

Ammonia systems are assumed to penetrate a greater percentage of non-U.S. markets as a result of 

different safety standards and greater acceptance by industry, end-users, regulators, and insurance 

companies in those countries. Assumptions on maximum market penetration for each region and year are 

presented in Tables 2-18 and 2-19. 

Enhanced HFC-134a Systems in MVACs

Various options exist to reduce emissions of HFC-134a in MVACs by reducing charge size, leakage 

rates, or system efficiency (i.e., reducing system power consumption). Specifically, reducing the volume 

of the system components, such as the condenser and refrigerant lines, can reduce charge size. Similarly, 

leakage rates can be lowered and system efficiency improved by using better system components, such as 

improved system sealing, lower permeation hoses, improved fittings, and higher evaporator 

temperatures (Lundberg, 2002; Xu and Amin, 2000). Additional savings of indirect emissions can be 

obtained by improving system efficiency, for example through the use of oil separators and externally 

controlled swashplate compressors. 
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IV-40 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

Based on the latest science and industry estimates available when this analysis was performed, 

enhanced HFC-134a systems can reduce baseline direct emissions by 50 percent (SAE, 2003a). This 

technology is not expected to become commercial until after 2006 (SAE, 2003a). This analysis assumes a 

project lifetime (i.e., MVAC lifetime) of 12 years. Regional technical applicabilities and the reduction 

efficiency are presented in Table 2-14. 

Table 2-14: Summary of Assumptions for Enhanced HFC-134a Systems for New MVACs 

Technical Applicabilityb

Country/Region 

Applicable EndUse Sector(s) Reduction 

Efficiencya 2010 2020 

United States and Japan 27.6% 19.9%

Other Annex I countries 42.8% 36.6%

Latin America and Caribbean 13.3% 12.0%

China, Hong Kong, and India 53.0% 65.8%

Other non-Annex I countries, Russian 

Federation, and Ukraine 

MVACs 50.0% 

3.8% 8.0%

a Reduction efficiency applies to all regions and represents the reduction in direct emissions (compared with conventional HFC-134a systems) 

as a result of reduced leakage. 

b Technical applicability is shown as a percentage of total refrigeration and air-conditioning sector emissions and equals the percentage of total 

refrigeration and air-conditioning sector emissions that are assumed to come from MVACs. 

Acceptance of this substitute would likely vary by region, based on consumer and industry attitudes, 

economic variables, and availability of competing options. Enhanced HFC-134a systems are expected to 

become commercially available several years before other alternatives (e.g., CO2 and HFC-152a). 

Therefore, this analysis assumes that, initially, enhanced HFC-134a systems will begin to penetrate the 

markets of developed countries—with the exception of Europe, which is expected to move away from 

HFC-134a use in MVACs in response to new EC legislation.21 In developed countries such as the United 

States, Japan, and Canada, where the industry is resistant to switching from HFC-134a and/or regulations 

phasing out the use of HFC-134a in MVACs do not exist, this option is assumed to gain the greatest 

market penetration. In developing countries, capital cost is expected to prevent this option from 

significantly penetrating the market before 2010; however, given the global market, these systems are 

expected to gain market share by 2020. The cost analysis for this option does not include any costs 

associated with retrofitting existing HFC-134a systems. Therefore, this option is assumed to penetrate 

only new MVACs produced after 2004. Assumptions on maximum market penetration for each region 

and year are presented in Tables 2-18 and 2-19. 

HFC-152a Refrigerant in MVACs

Replacing HFC-134a refrigerant in MVACs with HFC-152a represents a significant opportunity to 

reduce GWP-weighted HFC emissions, since the GWP of HFC-152a is 140, 89 percent less than that of 

HFC-134a, whose GWP is 1,300. HFC-152a is a flammable refrigerant but is less flammable than HCs. 

HFC-152a can be used in DX and secondary loop MVAC systems. Because there is still great uncertainty 

associated with the future costs of HFC-152a secondary loop systems for MVACs, this cost analysis only 

considers the DX option. Likewise, because there is still great uncertainty associated with future costs of 

improved HFC-152a MVACs, only the conventional DX systems are considered in this cost analysis. 

However, like the enhanced HFC-134a system discussed above, HFC-152a MVACs will use improved 

 

21 According to the EC Directive, HFC-134a will be phased out from 2011 onward for new vehicle models and from 

2017 for all new vehicles. The directive applies to gases with a GWP higher than 150 (EC, 2004). 
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GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES IV-41

system components to further reduce refrigerant leakage rates and increase system efficiency (e.g., 

externally controlled variable displacement compressors). 

In addition to direct emissions reductions associated with a lower GWP, HFC-152a DX systems in 

MVACs also reduce indirect emissions by improving system efficiency by about 10 percent (SAE, 2003a). 

This analysis assumes a project lifetime (i.e., MVAC lifetime) of 12 years. Regional technical 

applicabilities and the reduction efficiency are presented in Table 2-15. 

Table 2-15: Summary of Assumptions for HFC-152a DX Systems in New MVACs 

Technical Applicabilityb

Country/Region 

Applicable EndUse Sector(s) Reduction 

Efficiencya 2010 2020 

United States and Japan 27.6% 19.9%

Other Annex I countries 42.8% 36.6%

Latin America and Caribbean 13.3% 12.0%

China, Hong Kong, and India 53.0% 65.8%

Other non-Annex I countries, Russian 

Federation, and Ukraine 

MVACs 89.0% 

3.8% 8.0%

a Reduction efficiency applies to all regions and represents the reduction in direct emissions (compared with conventional HFC-134a systems) 

as a result of lower GWP. 

b Technical applicability is shown as a percentage of total refrigeration and air-conditioning sector emissions and equals the percentage of total 

refrigeration and air-conditioning sector emissions that are assumed to come from MVACs. 

The use of HFC-152a DX systems in MVACs would not require any significant changes to existing 

HFC-134a system components apart from a safety mitigation system (e.g., a refrigerant detector and a 

valve to isolate the remaining charge from the passenger compartment), thereby rendering this option 

easy to introduce into the market. Furthermore, compared with baseline HFC-134a systems, HFC-152a 

systems are expected to be more efficient and may operate at reduced refrigerant charges and leakage 

rates.22 However, because HFC-152a is a slightly flammable gas, safety systems are needed. Thus, 

personnel training would be needed to enable the safe and effective recovery and recycling of refrigerant 

at service and disposal, and additional safety systems to minimize the potential for large leaks into the 

passenger compartment may be required. New fire-safe service equipment for refrigerant recovery and 

charging and leak detection may also be required. 

While the MVAC industry has demonstrated the use of HFC-152a in prototype DX (and secondary 

loop) MVAC systems, the technology is still in the research and development phase. HFC-152a systems 

are expected to become commercially available between 2006 and 2008 (SAE, 2003a). Once available, it is 

assumed that, initially, HFC-152a systems will gain market share in developed countries, although use in 

Europe will be tempered by conditions that may favor CO2 systems. Market penetration in developing 

countries is expected to lag by about 5 years. Retrofitting HFC-134a systems to HFC-152a systems is not 

considered technically or economically feasible, because it is assumed that additional safety systems to 

reduce potential passenger exposure must be incorporated into the system. Thus, costs associated with 

retrofit were not assessed, and this option is assumed to penetrate only new MVACs produced after 2004. 

Assumptions on maximum market penetration for each region and year are presented in Tables 2-18 and 

2-19. 

 

22 Because these systems are still under development, this cost analysis does not consider the possible reduction in 

charge and leakage rates, although efficiency improvement predictions based on SAE (2003a) are included. 
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IV-42 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

CO2 in MVACs

Systems that use CO2 as the refrigerant in MVACs represent a potential opportunity for emissions 

reduction. This technology uses a transcritical vapor cycle that differs from conventional MVAC systems 

and requires innovative design and engineering. The arrangement of components in CO2 systems is 

generally consistent with conventional systems; however, a suction line heat exchanger is added and a 

low side accumulator is used (in place of a high side receiver, which is used in most conventional HFC134a systems). In addition, the individual system components are designed to reflect the extremely high 

pressure levels of supercritical CO2 (about 2,000 pounds per square inch [psig]). 

Because CO2 has a GWP of 1, its use would virtually eliminate the climate impacts of direct 

refrigerant emissions from MVACs. CO2 systems perform most efficiently in areas like northern Europe 

that require air conditioners for cooling and other purposes, but generally have mild ambient 

temperatures.23 In addition, heat pump technology for vehicles is under development (VDA, 2003), which 

may allow CO2 systems to be used for supplemental heating of the passenger compartment (SAE, 2003a). 

This technology may be an important function in cars with very efficient engines, where minimal waste 

heat is available to warm the passenger compartment. 

While CO2 has the advantage of being non-flammable, it is toxic. A short exposure to elevated levels 

of CO2 can lead to dizziness, drowsiness, and even death (Lambertsen, 1971; Wong, 1992). In addition, 

CO2 system operating pressure is 5 to 10 times that of HFC-134a; therefore, appropriate safety features 

and new system and component designs are required before this option can be brought to market. 

Furthermore, an internal heat exchanger, which would further cool the high-temperature CO2 from the 

gas cooler and heat the low-temperature CO2 from the accumulator, would be needed to increase cooling 

capacity and energy efficiency to acceptable levels. Also, in the event of a large leak, passengers could be 

exposed to potentially dangerous levels of CO2; thus, it is assumed that safety systems designed to 

minimize passenger exposure would be incorporated into the system design. 

Several engineering constraints must still be overcome, including those associated with flexible lines, 

increased system weight, and system leakage and leak detection methods. In addition, because these 

systems will be designed and built differently than current MVACs and because the high pressure 

presents additional risks, technicians will need to be trained on how to service and maintain these new 

systems safely and correctly in order to prevent safety hazards and maintain system performance. New 

service equipment for refrigerant charging and leak detection may also be required. Moreover, because of 

the high pressure of these systems and toxicity concerns, MVAC servicing and maintenance would need 

to be performed by skilled technicians, to prevent safety hazards and maintain system performance. 

The efficiency gains associated with CO2 systems are between 20 and 25 percent (SAE, 2003a). In this 

cost analysis, 22.5 percent is used for calculation purposes. While there are ongoing efforts to develop 

improved CO2 systems for MVACs—which experts predict would exceed this 20 to 25 percent energy 

efficiency gain—much uncertainty remains regarding the investment costs required to manufacture these 

systems. Therefore, these improved CO2 systems are not considered further in this analysis. The assumed 

project lifetime (i.e., MVAC lifetime) is 12 years. Regional technical applicabilities and the reduction 

efficiency for the CO2 option are presented in Table 2-16. 

 

23 Compared with other refrigerant technologies, prototype CO2 MVAC systems are not as efficient in warmer 

climates. The MVAC industry is actively pursuing research and development activities to improve system efficiency 

in warmer weather conditions (SAE, 2003b). 
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GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES IV-43

Table 2-16: Summary of Assumptions for CO2 Systems in New MVACs 

Technical Applicabilityb

Country/Region 

Applicable EndUse Sector(s) Reduction 

Efficiencya 2010 2020 

United States and Japan 27.6% 19.9%

Other Annex I countries 42.8% 36.6%

Latin America and Caribbean 13.3% 12.0%

China, Hong Kong, and India 53.0% 65.8%

Other non-Annex I countries, Russian 

Federation, and Ukraine 

MVACs 100.0% 

3.8% 8.0%

a Reduction efficiency applies to all regions and represents the reduction in direct emissions (compared with conventional HFC-134a systems). 

b Technical applicability is shown as a percentage of total refrigeration and air-conditioning sector emissions and equals the percentage of total 

refrigeration and air-conditioning sector emissions that are assumed to come from MVACs. 

CO2 systems may be available on the market in the next few years (SAE, 2003a). In light of the new 

EC directive on MVACs, and because European manufacturers are most aggressively pursuing CO2, this 

option is expected to become the dominant market player in this market. In other developed countries, 

such as the United States, Australia, New Zealand, and Canada, the industry is not developing this 

technology as aggressively, and it is assumed that this option will not be widely adopted in these markets 

in the near future. Finally, because of the high capital costs associated with this option (see details below), 

this technology is also not expected to be adopted in developing countries until later years, assuming a 

projected global market shift to non-GWP alternatives. The project lifetime is assumed to be 12 years, and 

assumptions on maximum market penetration for each region and year are presented in Tables 2-18 and 

2-19. Retrofitting HFC-134a systems to CO2 is not considered technically or economically feasible because 

of the high operating pressures and because it is assumed that additional safety systems to reduce 

potential passenger exposure must be incorporated into the systems. Thus, costs to retrofit were not 

assessed, and this option is assumed to penetrate only new MVACs produced after 2004. 

Oil-Free Compressors

Oil-free compressors are available for chillers, industrial process applications, and other applications 

where compressors are used. The elimination of oil in refrigeration and air-conditioning compressors has 

been achieved through various innovative designs, including the incorporation of magnetic or hybrid 

ceramic bearings (SKF, 2003; Smithart, 2003). In some systems, oil may decrease heat transfer and reduce 

operating efficiency; therefore, removing oil may increase the ability to sustain system efficiency over the 

life of the equipment. This reduction will lower indirect emissions of CO2 associated with electricity 

production. Eliminating the use of oil in compressors can reduce the number of equipment components 

(e.g., oil separators and sealing, fittings, and connections), allowing equipment to be made tighter, 

resulting in lower leakage rates. In addition, oil-free compressors remove the need for oil changes and the 

associated refrigerant emissions that may be experienced through the service practices used or from 

refrigerant dissolved in the oil. However, this potential emissions reduction may be offset by an increased 

frequency of compressor and bearing inspection or replacement (Digmanese, 2004), although an 

increasing history of operation may prove that unnecessary. This option was not included in the cost 

analysis because limited data were available. 

Geothermal Cooling Systems

In some locations, geothermal cooling systems for residential and commercial spaces are popular and 

economically sound as an alternative to conventional air-conditioning systems. Geothermal technology 

transfers heat between the system and the earth and can provide both space heating and cooling. Though 
SECTION IV — INDUSTRIAL PROCESSES • REFRIGERATION AND AIR-CONDITIONING 

IV-44 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

installation costs for geothermal systems are typically 30 percent to 50 percent higher than for 

conventional systems, annual costs are reduced by 20 percent to 40 percent because of increased energy 

efficiency. Economic paybacks can accrue in as little as 3 to 5 years. Geothermal systems may save 

homeowners 20 percent to 50 percent in cooling costs (Geoexchange, 2000; Rawlings, 2000). Because of a 

lack of cost and market penetration data, this technology is not considered further in this analysis. 

Desiccant Cooling Systems

Desiccant cooling is produced by removing moisture from an air stream using a desiccant and then 

separately cooling the dry air. The desiccant is thermally regenerated, typically by burning natural gas or 

by capturing excess heat. Desiccant cooling may replace the latent cooling done by some end-uses, such 

as unitary systems. Integrated desiccant cooling systems that combine a desiccant system with a vapor 

compression or other cooling system have been successfully installed in some commercial buildings 

(Fisher, Tomlinson, and Hughes, 1994). However, current designs are used primarily in niche markets 

that require precisely controlled humidity or low humidity levels, such as hospital operating rooms and 

certain industrial processes. For desiccant-based systems to be considered widely feasible in the 

commercial air-conditioning market, improvements in efficiency, cost, size, reliability, and life expectancy 

must be made (Sand et al., 1997). 

Desiccant systems have also been tried in MVAC systems, but were found technically and 

economically infeasible. These systems require an intermittent source of heat; however, because new 

automobiles produce very little waste heat, there is not enough heat for a desiccant system to function. 

Desiccant systems may only be feasible where there is a large heat source, such as a large truck or bus 

(Environment Canada, 1998). Furthermore, in order for desiccant air-conditioners to become viable 

options for MVACs, the varying heat source must be controlled during normal driving conditions when 

vehicle speed is continually changing. Current prototypes are large and heavy, and the systems have not 

been shown to be cost-effective or durable enough to justify the initial investment (USEPA, 2001a). 

Because of the technical barriers and insufficient cost information associated with the feasibility of 

this option, desiccant cooling systems were not explored further in this analysis. 

Absorption Systems

Absorption systems refrigerate or cool using two fluids and some quantity of heat input, rather than 

using electrical input. Specifically, absorption systems use a secondary fluid or absorbent to circulate the 

refrigerant (Rafferty, 2003). These systems can be used in residential refrigeration and chiller applications 

and, potentially, in heat pumps in residential and light commercial applications, as described below. 

• Refrigeration Systems. In the late 1990s, more than 1 million of an estimated 62 million 

refrigerators sold annually were thermally activated ammonia or water absorption systems (Sand 

et al., 1997). The refrigerants used for absorption refrigeration have negligible GWPs. Absorption 

refrigeration is commonly used in hotel rooms and for recreational vehicles because the process 

operates quietly and can use bottled gas for energy. Absorption refrigerators are limited in size 

because of design constraints. Through design improvements, the thermal coefficient of 

performance (COP) of these refrigerators can be increased by as much as 50 percent from a COP 

of 0.2 to 0.3 without degrading cooling capacity (Sand et al., 1997). However, the low efficiency of 

absorption equipment means that the indirect emissions must be carefully analyzed. Inherent 

design limitations make it unlikely that absorption refrigeration will become a significant 

replacement for vapor compression refrigerators. Still, absorption refrigeration has great capacity 

and operating attributes that permit the technology to fill niche markets (Sand et al., 1997). 
SECTION IV — INDUSTRIAL PROCESSES • REFRIGERATION AND AIR-CONDITIONING 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES IV-45

• Chillers. Gas-fired (as opposed to electrically powered) absorption water chillers are sold in the 

United States and Japan. These systems are used primarily where there is a relatively short 

cooling season, where electricity costs (especially demand charges) are high, or where fairly highgrade waste heat is available. Although absorption chillers are far less efficient than competitive 

systems if waste heat is unavailable, the technology is feasible and, under some economic 

circumstances, compares favorably with vapor compression chillers using fluorocarbon 

refrigerants. Market success will be determined by factors such as the relative costs of natural gas 

and electricity, peak load charges, and purchase costs. In addition, absorption chillers currently 

have higher capital costs than vapor compression equipment, such that significant operating cost 

savings would be necessary to make their purchase economically competitive. 

• Heat Pumps. Research and development efforts are attempting to create absorption heat pumps 

for heating and cooling in residential and light commercial applications. Several years ago in 

Europe and the United States, generator absorber heat exchange (GAX) ammonia-water 

absorption heat pumps were being developed and in Japan field test units had been built. 

Absorption heat pumps could be used to reduce global warming impacts in areas where heating 

load dominates, although the pumps would have the opposite effect in areas where cooling 

dominates (Sand et al., 1997). 

Because these options are either still under development or are primarily optimal in niche markets, 

sufficient information was not available to include their costs and reduction potential in this analysis. 

IV.2.3.2 Summary of Technical Applicability, Market Penetration, and Costs of 

Abatement Options 

Table 2-19 summarizes the percentage of total refrigeration and air-conditioning sector emissions that 

may be technically abated by each of the options explored in this analysis, based on the percentage of 

sector emissions from each end-use (which varies by region), as provided in Table 2-6. Market 

penetration values for each abatement option were developed for each region, when possible, to best 

reflect qualitative information available on region-specific realities and possible future action. The 

commercial refrigeration and MVAC technology options explored in this chapter are assumed to 

penetrate only new (not existing) equipment, where new equipment is defined as equipment 

manufactured in 2005 or later. Table 2-18 presents the assumed maximum market penetration for the 

technology options into equipment manufactured in 2005, 2010, 2015, and 2020. Table 2-19 presents the 

final maximum penetration into the installed base of equipment, taking into account the percentage of 

each market that is new (i.e., manufactured in 2005 or beyond) in all preceding years. Values from 

Table 2-19 are multiplied by technical applicabilities (Table 2-17) and the reduction efficiency to generate 

the percentage reduction off baseline emissions for each option, as presented in Table 2-20. The text box 

provided in Section IV. 2.4provides further explanation on how the results (i.e., percentage reduction off 

baseline emissions) are calculated. 

IV.2.4 Results 

Emissions reduction potential for abatement options varies by region based on assumed end-use 

breakouts (provided in Table 2-6) and on qualitative information regarding current and future likelihood 

of market penetration by region. The percentage reduction from the baseline associated with each 

abatement option is calculated by multiplying the technical applicability (from Table 2-17) by both the 

incremental maximum market penetration (from Table 2-18) and the reduction efficiency. For more 
SECTION IV — INDUSTRIAL PROCESSES • REFRIGERATION AND AIR-CONDITIONING 

IV-46 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

information on how emissions reductions are calculated for each option, please see the text box below, 

which presents an illustrative example of the emissions reduction methodology. 

Calculating Emissions Reductions for Each Abatement Option 

The equation used to derive total emissions reductions off the baseline for each option is as follows: 

Emissions Reduction = technical applicability × incremental maximum market penetration 

(expressed as percentage of entire installed base) × reduction efficiency 

The following table provides a sample calculation using the option of leak repair for large equipment 

in the United States in 2020 as an example. 

Sample Calculation of Emissions Reductions: Leak Repair for Large Equipment—United States (2020) 

Applicable EndUses 

(Table 2-9) 

Technical 

Applicabilitya

(Based on Tables 

2-6 and 2-9) 

Incremental 

Maximum Market 

Penetration 

(Table 2-19) 

Reduction 

Efficiency 

(Table 2-9) 

Percentage 

Reduction from 

2020 Baseline 

(Table 2-20) 

Chillers 1.5 × 50% 5% 40% 0.02 

Retail food 39.1 × 50% 5% 40% 0.39 

Cold storage 1.4 × 50% 5% 40% 0.01 

Industrial 

process 

6.6 × 50% 5% 40% 0.07 

Total 48.7 × 50% × 5% × 40% = 0.49b

a For each country/region, technical applicability varies based on the percentage of sector emissions from applicable end-uses, as 

provided in Table 2-6. Additionally, for the leak repair and refrigerant recovery and recycling options, only half of the emissions from 

applicable end-uses (i.e., large end-uses for leak repair and small end-uses for recovery and recycling) are assumed to be abatable; 

for all other options, 100 percent of emissions from new (post-2004) equipment in applicable end-uses are assumed to be abatable. 

b Total may not sum due to independent rounding. 

Table 2-21 presents a summary of the cost assumptions used for the refrigeration/air-conditioning 

options presented in the discussions above. 

IV.2.4.1 Data Tables and Graphs 

Tables 2-22 and 2-23 provide a summary of the potential emissions reductions at various breakeven 

costs by country/region in 2010 and 2020, respectively. The costs to reduce 1 tCO2eq are presented at a 10 

percent discount rate and 40 percent tax rate. Table 2-24 presents the potential emissions reduction 

opportunities and associated annualized costs for the world in 2020 ordered by increasing costs per 

tCO2eq, using the highest cost in the region. Because many of the options analyzed affect indirect (CO2

from energy generation) emissions, the net (HFC + CO2) emissions reduced by each option are presented. 

The direct (HFC) emissions reduced by the option and a cumulative total of direct emissions reduced, in 

MtCO2eq and percentage of the regional refrigeration and air-conditioning baseline, are also presented. 

Figures 2-2 and 2-3 present MACs for this sector at 10 percent discount rates and 40 percent tax rates in 

2010 and 2020, respectively. 
SECTION IV — INDUSTRIAL PROCESSES • REFRIGERATION AND AIR-CONDITIONING 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES IV-47 Table 2-17: Summary of Technical Applicability of Abatement Options by Region (Percent)a United States and Japan China, Hong Kong, and India Europe, Australia, New Zealand, and All Other Annex I Countries Latin America and Caribbean Russian Federation, Ukraine, and All Non- Annex I Countries Abatement Option

2005

2010

2015

2005

2005

2010

2015

2020

2005

2010 

2015

2020

2005

2010

2015

2020

2005

2010

2015

2020

Refrigerant recovery 

from small equipment 

26.0 24.3 24.6 25.7 28.1 33.3 37.5 39.6 30.1 29.7 27.6 30.7 17.9 19.2 21.3 23.3 14.0 15.8 19.0 22.1 

Leak repair for large 

equipment 

24.0 25.7 25.4 24.3 21.9 16.7 12.5 10.4 19.9 20.3 22.4 19.3 32.1 30.8 28.7 26.7 36.0 34.2 31.0 27.9 

Ammonia secondary 

loop 

40.2 43.1 42.6 40.6 36.8 28.0 20.9 17.3 33.3 34.1 37.5 32.1 53.8 51.7 48.1 44.5 60.3 57.3 52.1 46.6 

Distributed system 40.2 43.1 42.6 40.6 36.8 28.0 20.9 17.3 33.3 34.1 37.5 32.1 53.8 51.7 48.1 44.5 60.3 57.3 52.1 46.6 HFC secondary loop 

system 

40.2 43.1 42.6 40.6 36.8 28.0 20.9 17.3 33.3 34.1 37.5 32.1 53.8 51.7 48.1 44.5 60.3 57.3 52.1 46.6 

Enhanced HFC-134a in 

MVACs 

35.9 27.6 22.6 19.9 41.3 53.0 62.0 65.8 46.9 42.8 31.8 36.6 14.2 13.3 12.6 12.0 3.8 3.8 5.4 8.0 

HFC-152a in MVACs 35.9 27.6 22.6 19.9 41.3 53.0 62.0 65.8 46.9 42.8 31.8 36.6 14.2 13.3 12.6 12.0 3.8 3.8 5.4 8.0 CO2 in MVACs 35.9 27.6 22.6 19.9 41.3 53.0 62.0 65.8 46.9 42.8 31.8 36.6 14.2 13.3 12.6 12.0 3.8 3.8 5.4 8.0 

a Expressed as a percentage of total refrigeration and air-conditioning emissions. 
SECTION IV — INDUSTRIAL PROCESSES • REFRIGERATION AND AIR-CONDITIONING 

IV-48 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES Table 2-18: Assumed Regional Market Penetration of Abatement Options into Newly Manufactured Equipment, Expressed as a Percentage of Emissions from New Equipmenta United States Europeb Japan, Australia, & New Zealand All Other Annex I Countries China, Hong Kong, & India Latin America & Caribbean, Russian Federation, Ukraine, & All Other Non-Annex I Countries

2005

2010

2015

2020

2005

2010

2015

2020

2005

2010

2015

2020

2005

2010

2015

2020

2005

2010

2015

2020

2005

2010

2015

2020

Practice OptionsRefrigerant recovery from 

small equipment 

ND ND ND ND ND ND 

Leak repair for large 

equipment 

ND ND ND ND ND ND 

Technology Options Ammonia secondary loop 3 5 13 20 5 10 13 15 5 10 13 15 5 10 13 15 5 10 10 10 5 10 10 10 Distributed system 8 15 23 30 10 20 30 40 10 20 30 40 10 20 30 40 8 15 20 25 8 15 20 25 HFC secondary loop 

system 

8 15 23 30 5 10 18 25 5 10 18 25 5 10 18 25 8 10 13 20 8 10 13 20 

Enhanced HFC-134a in 

MVACs 

0 40 50 60 0 0 0 0 0 40 50 60 0 40 50 60 0 5 20 40 0 5 20 40 

HFC-152a in MVACs 0 1 20 30 0 1 15 25 0 1 20 30 0 1 20 30 0 0 1 20 0 0 1 20 CO2 in MVACs 0 1 5 10 0 15 65 75 0 1 5 10 0 1 5 10 0 0 1 5 0 0 1 5 

a Expressed as a percentage of new equipment for the given year. The baseline market penetration of all technology options is assumed to be zero so that only incremental market penetration is 

analyzed. 

b Europe is assumed to include the EU-25 countries, Croatia, Norway, Romania, Switzerland, Turkey, Bulgaria, and Macedonia. 

ND: No distinction was made between market penetration assumptions into new versus existing equipment. 
SECTION IV — INDUSTRIAL PROCESSES • REFRIGERATION AND AIR-CONDITIONING 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES IV-49 Table 2-19: Market Penetration of Abatement Options, Expressed as a Percentage of Total Sector Emissionsa United States Europec Japan, Australia, & New Zealand All Other Annex I Countries China, Hong Kong, & India Latin America & Caribbean, Russian Federation, Ukraine, & All Other Non- Annex I Countries

2005

2010

2015

2020

2005

2010

2015

2020

2005

2010

2015

2020

2005

2010

2015

2020

2005

2010

2015

2020

2005

2010

2015

2020

Practice Options Refrigerant recovery 

from small equipmentb

5.0 10.0 10.0 15.0 5.0 10.0 10.0 15.0 5.0 10.0 10.0 15.0 5.0 10.0 10.0 15.0 20.0 30.0 40.0 50.0 20.0 30.0 40.0 50.0 

Leak repair for large 

equipment 

3.0 3.0 5.0 5.0 3.0 3.0 5.0 5.0 3.0 3.0 5.0 5.0 3.0 3.0 5.0 5.0 5.0 10.0 12.0 15.0 5.0 10.0 12.0 15.0 

Technology 

Options 

Ammonia secondary 

loop 

0.2 1.4 4.3 9.4 0.3 2.6 6.1 10.3 0.3 2.6 6.1 10.3 0.3 2.6 6.1 10.3 0.3 2.6 5.6 8.5 0.3 2.6 5.6 8.5 

Distributed system 0.5 4.1 9.9 17.9 0.6 5.3 12.9 23.5 0.6 5.3 12.9 23.5 0.6 5.3 12.9 23.5 0.5 4.1 9.4 16.1 0.5 4.1 9.4 16.1 HFC secondary loop 

system 

0.5 4.1 9.9 17.9 0.3 2.6 7.0 13.5 0.3 2.6 7.0 13.5 0.3 2.6 7.0 13.5 0.5 3.2 6.6 11.7 0.5 3.2 6.6 11.7 

Enhanced HFC134a in MVACs 0.0 10.0 29.2 48.5 0.0 0.0 0.0 0.0 0.0 10.0 29.2 48.5 0.0 10.0 29.2 48.5 0.0 1.3 7.1 19.9 0.0 1.3 7.1 19.9 HFC-152a in 

MVACs 

0.0 0.3 5.4 16.2 0.0 0.3 4.2 12.8 0.0 0.3 5.4 16.2 0.0 0.3 5.4 16.2 0.0 0.0 0.3 5.4 0.0 0.0 0.3 5.4 

CO2 in MVACs 0.0 0.3 1.7 4.9 0.0 3.8 22.5 50.6 0.0 0.3 1.7 4.9 0.0 0.3 1.7 4.9 0.0 0.0 0.3 1.7 0.0 0.0 0.3 1.7 

a Total sector emissions include those from new and existing equipment (i.e., the entire installed base). The baseline market penetration is assumed to be zero, unless otherwise noted. b Shown percentage values are incremental relative to the baseline market penetration, which is assumed to be 80 percent in developed countries and 30 percent in developing countries. c Europe is assumed to include the EU-25 countries, Croatia, Norway, Romania, Switzerland, Turkey, Bulgaria, and Macedonia. 
SECTION IV — INDUSTRIAL PROCESSES x REFRIGERATION AND AIR-CONDITIONING 

IV-50 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

Table 2-20: Percentage of (Direct)a Reduction Off Baseline Emissions of All Abatement Options by Region 

United States Europeb Japan

Australia and New 

Zealand

2005201020152020200520102015202020052010201520202005201020152020

Practice Options 

Refrigerant recovery 

from small 

equipment

1.1 2.1 2.1 3.3 1.3 2.5 2.4 3.9 1.1 2.1 2.1 3.3 1.3 2.5 2.4 3.9

Leak repair for large 

equipment

0.3 0.3 0.5 0.5 0.2 0.2 0.4 0.4 0.3 0.3 0.5 0.5 0.2 0.2 0.4 0.4

Technology Options 

Ammonia secondary 

loop

0.1 0.6 1.8 3.8 0.1 0.9 2.3 3.3 0.1 1.1 2.6 4.2 0.1 0.9 2.3 3.3

Distributed system 0.2 1.6 3.8 6.5 0.2 1.6 4.4 6.8 0.2 2.1 5.0 8.6 0.2 1.6 4.4 6.8

HFC secondary loop 

system

0.2 1.6 3.9 6.8 0.1 0.8 2.5 4.1 0.1 1.1 2.8 5.1 0.1 0.8 2.5 4.1

Enhanced HFC-134a 

in MVACs 

0.0 1.4 3.3 4.8 0.0 0.0 0.0 0.0 0.0 1.4 3.3 4.8 0.0 2.1 4.6 8.9

HFC-152a in MVACs 0.0 0.1 1.1 2.9 0.0 0.1 1.2 4.2 0.0 0.1 1.1 2.9 0.0 0.1 1.5 5.3

CO2 in MVACs 0.0 0.1 0.4 1.0 0.0 1.6 7.2 18.5 0.0 0.1 0.4 1.0 0.0 0.1 0.5 1.8

All Other Annex I 

Countries

China, Hong Kong, & 

India

Latin America & 

Caribbean

Russian Federation, 

Ukraine, & All Other 

Non-Annex I Countries

2005201020152020200520102015202020052010201520202005201020152020

Practice Options 

Refrigerant recovery 

from small 

equipment

1.3 2.5 2.4 3.9 4.8 8.5 12.8 16.8 3.0 4.9 7.3 9.9 2.4 4.0 6.5 9.4

Leak repair for large 

equipment

0.2 0.2 0.4 0.4 0.4 0.7 0.6 0.6 0.6 1.2 1.4 1.6 0.7 1.4 1.5 1.7

Technology Options 

Ammonia secondary 

loop

0.1 0.9 2.3 3.3 0.1 0.7 1.2 1.5 0.2 1.4 2.7 3.8 0.2 1.5 2.9 4.0

Distributed system 0.2 1.6 4.4 6.8 0.2 1.0 1.8 2.5 0.2 1.9 4.0 6.5 0.3 2.1 4.4 6.8

HFC secondary loop 

system

0.1 0.8 2.5 4.1 0.2 0.8 1.3 1.9 0.2 1.5 3.0 4.9 0.3 1.7 3.2 5.1

Enhanced HFC-134a 

in MVACs 

0.0 2.1 4.6 8.9 0.0 0.3 2.2 6.6 0.0 0.1 0.4 1.2 0.0 0.0 0.2 0.8

HFC-152a in MVACs 0.0 0.1 1.5 5.3 0.0 0.0 0.1 3.2 0.0 0.0 0.0 0.6 0.0 0.0 0.0 0.4

CO2 in MVACs 0.0 0.1 0.5 1.8 0.0 0.0 0.2 1.1 0.0 0.0 0.0 0.2 0.0 0.0 0.0 0.1

a Direct reductions refer to HFC emissions reductions; indirect emissions impacts associated with energy consumption are not reflected in this 

table (and are not included in the baseline).

b Europe is assumed to include the EU-25 countries, Croatia, Norway, Romania, Switzerland, Turkey, Bulgaria, and Macedonia. 
SECTION IV — INDUSTRIAL PROCESSES • REFRIGERATION AND AIR-CONDITIONING 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES IV-51

Table 2-21: Summary of Abatement Option Cost Assumptions (2000$) 

Option 

Time 

Horizon 

(Years) Unit of Costs 

U.S. OneTime Cost 

U.S. 

Annual 

Cost 

U.S. 

Annual 

Savings 

Net U.S. 

Annual 

Costs 

Refrigerant recovery 1 Per recovery job —a $10.10 $13.71 –$3.61 

Distributed system 15 Per 60,000 ft2

supermarket 

$7,200.00 $2,796.19b $3,559.94 –$763.75 

Secondary loop 15 Per 60,000 ft2

supermarket 

$25,200.00 $5,592.38b $3,691.79 $1,900.59 

Ammonia secondary loop 15 Per 60,000 ft2

supermarket 

$36,000.00 $5,592.38b $3,955.49 $1,636.89 

Leak repair 1 Per repair job $1,480.00c — $2,636.99 –

$2,636.99 

CO2 for new MVACs 12 Per MVAC $105.30 — $18.35d –$18.35 

Enhanced HFC-134a in 

MVACs 

12 Per MVAC $42.12 — $21.38d –$21.38 

HFC-152a in MVACs 12 Per MVAC $23.69 — $7.92e –$7.92 

a The cost of a high-pressure recovery unit is assumed to be approximately $860, but all costs associated with this option, including capital 

costs, are annualized and expressed in terms of cost per job. 

b In all other countries, this annual cost was adjusted by average electricity prices (average of 1994–1999) based on USEIA (2000). c Includes parts and labor to perform repair job. 

d Annual U.S. costs savings are associated with gasoline and refrigerant savings. For all other countries, the annual saving associated with 

gasoline in the United States is adjusted by the estimated amount of gasoline saved per vehicle per year (based on Rugh and Hovland 

[2003]) and by average regional costs of unleaded gasoline in 2003 (based on USEIA [2005]). No adjustments are made to the savings 

associated with refrigerant. 

e Annual U.S. costs savings are associated with gasoline savings. For all other countries, this annual savings is adjusted by the estimated 

amount of gasoline saved per vehicle per year (based on Rugh and Hovland [2003]) and by average regional costs of unleaded gasoline in 

2003 (based on USEIA [2005]). 
SECTION IV — INDUSTRIAL PROCESSES • REFRIGERATION AND AIR-CONDITIONING 

IV-52 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

Table 2-22: Country/Regional Emissions Reductions in 2010 and Breakeven Costs for Refrigeration/AirConditioning at 10% Discount Rate, 40% Tax Rate ($/tCO2eq) 

2010 

Country/Region $0 $15 $30 $45 $60 >$60 

Africa 0.69 1.04 1.37 1.37 1.37 1.37 

Annex I 9.08 17.51 18.63 18.63 19.34 19.38 

Australia/New Zealand 0.09 0.20 0.27 0.27 0.27 0.27 

Brazil 0.42 0.75 0.76 0.76 0.76 0.76 

China & Hong Kong 2.63 3.03 3.12 3.12 3.12 3.12 

Eastern Europe 0.15 0.27 0.27 0.27 0.34 0.34 

EU-15 1.08 2.25 2.36 2.36 2.97 2.97 

India 0.24 0.29 0.31 0.31 0.31 0.31 

Japan 1.22 1.91 2.63 2.63 2.63 2.65 

Mexico 0.40 0.72 0.73 0.73 0.73 0.73 

Non-OECD Annex I 0.62 0.90 0.91 0.91 0.94 0.94 

OECD 9.86 19.32 20.44 20.44 21.12 21.16 

Russian Federation 0.52 0.74 0.75 0.75 0.75 0.75 

South & SE Asia 0.79 1.57 1.57 1.57 1.57 1.57 

United States 5.67 11.44 11.44 11.44 11.44 11.44 

World Total 16.60 29.20 31.03 31.03 31.73 31.77 

EU-15 = European Union; OECD = Organisation for Economic Co-operation and Development. 

Table 2-23: Country/Regional Emissions Reductions in 2020 and Breakeven Costs for Refrigeration/AirConditioning at 10% Discount Rate, 40% Tax Rate ($/tCO2eq) 

2020 

Country/Region $0 $15 $30 $45 $60 >$60 

Africa 2.26 4.06 5.73 5.73 5.73 5.76 

Annex I 43.63 109.62 117.89 117.89 130.65 131.50 

Australia/New Zealand 0.24 1.03 1.81 1.81 1.81 1.91 

Brazil 1.38 3.19 3.41 3.41 3.41 3.43 

China & Hong Kong 12.33 14.41 20.41 20.41 20.41 21.09 

Eastern Europe 0.81 1.66 1.66 1.66 2.96 2.96 

EU-15 4.95 12.48 13.22 13.22 24.03 24.03 

India 0.94 1.18 1.79 1.79 1.79 1.85 

Japan 3.87 9.03 13.22 13.22 13.22 13.66 

Mexico 1.29 2.99 3.19 3.19 3.19 3.22 

Non-OECD Annex I 2.89 4.49 4.74 4.74 5.25 5.28 

OECD 45.69 117.04 125.65 125.65 137.90 138.79 

Russian Federation 2.39 3.60 3.76 3.76 3.76 3.78 

South & SE Asia 3.11 7.56 7.89 7.89 7.89 7.93 

United States 30.26 78.05 78.05 78.05 78.05 78.05 

World Total 73.22 161.70 181.11 181.11 193.94 195.80 

EU-15 = European Union; OECD = Organisation for Economic Co-operation and Development. 
SECTION IV — INDUSTRIAL PROCESSES • REFRIGERATION AND AIR-CONDITIONING 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES IV-53

Table 2-24: World Breakeven Costs and Emissions Reductions in 2020 for Refrigeration/Air-Conditioning 

Cost (2000$/tCO2eq) 

DR=10%, TR=40% 

Reduction Option Low High 

Direct 

Emissions 

Reductiona 

(MtCO2eq) 

Indirect 

Emissions 

Reductionb 

(MtCO2eq) 

Reduction 

from 2020 

Baseline 

(%) 

Running 

Sum of 

Reductions 

(MtCO2eq) 

Cumulative 

Reduction 

from 2020 

Baseline 

(%) 

Leak repair –$4.10 –$4.10 4.91 0.00 0.8% 4.91 0.8% 

Refrigerant recovery –$2.62 –$2.62 40.16 0.00 6.4% 45.07 7.2% 

Distributed system –$1.08 $9.99 39.67 –0.43 6.3% 84.74 13.5% 

Enhanced HFC-134a in 

MVACs 

–$175.92 $16.21 22.69 21.67 3.6% 107.44 17.1% 

HFC-152a in MVACs –$27.59 $18.18 15.72 0.81 2.5% 123.16 19.6% 

Ammonia secondary 

loop 

$6.33 $26.40 22.18 –2.71 3.5% 145.34 23.2% 

HFC secondary loop $4.81 $26.70 33.20 –0.06 5.3% 178.54 28.5% 

CO2 for new MVACs $7.57 $91.60 17.26 1.83 2.8% 195.80 31.2% 

a Direct reductions refer to HFC emissions reductions (off the baseline). 

b Indirect emissions impacts are those associated with energy consumption (not included in the baseline). 

Figure 2-2: 2010 MAC for Refrigeration/Air-Conditioning, 10% Discount Rate, 40% Tax Rate 

EU-15 = European Union; OECD = The Organisation for Economic Co-operation and Development. 
SECTION IV — INDUSTRIAL PROCESSES • REFRIGERATION AND AIR-CONDITIONING 

IV-54 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

Figure 2-3: 2020 MAC for Refrigeration/Air-Conditioning, 10% Discount Rate, 40% Tax Rate 

EU-15 = European Union; OECD = The Organisation for Economic Co-operation and Development. 

IV.2.4.2 Uncertainties and Limitations 

This section focuses on the uncertainties and limitations of the cost estimates presented in this 

analysis. One significant area of uncertainty is how capital costs for these mitigation technologies may 

vary internationally. The analysis is currently limited by the lack of this specificity on region-specific cost 

analysis estimates. In addition, the main uncertainties related to the following abatement options are 

listed below. 

Leak Repair for Large Equipment 

Because leak repair can be performed on many different equipment types and can involve many 

different activities/tools, it is difficult to determine an average cost of such repairs or the average 

emissions reduction associated with them. This analysis, therefore, relies on broad assumptions available 

in the published literature, which may not reflect specific or even average values for the leak repair 

activities modeled. 

Refrigerant Recovery for Small Equipment 

Estimates of the amount of refrigerant recoverable from MVACs and small appliances at service and 

disposal are highly uncertain. This analysis uses the estimates provided in USEPA (1998). 

Stationary Technology Options (Distributed, HFC Secondary Loop, and Ammonia Secondary 

Loop Systems) 

This analysis assumes that emissions savings equal to 56 percent of the original equipment charge are 

realized at disposal in the distributed and HFC and ammonia secondary loop options; however, the 

actual amount of charge emitted at disposal is uncertain. 

IV.2.5 Summary 

Baseline HFC emissions from refrigeration and air-conditioning are expected to grow significantly 

between 2005 and 2020, as HFCs become used increasingly throughout the world to replace gases phased 
SECTION IV — INDUSTRIAL PROCESSES • REFRIGERATION AND AIR-CONDITIONING 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES IV-55

out under the Montreal Protocol. The highest percentage of emissions growth is expected to occur in 

developing countries. 

This analysis considers the costs and emissions reduction potential of eight practice and technology 

emissions mitigation options: (1) leak repair for large equipment, (2) refrigerant recovery and recycling 

from small equipment, (3) distributed system, (4) HFC secondary loop, (5) ammonia secondary loop, 

(6) enhanced HFC-134a systems in MVACs, (7) HFC-152a systems in MVACs, and (8) CO2 systems in 

MVACs. The costs and emissions reduction benefits of each option were compared for each region. 

Increasing leak repair of large equipment and refrigerant recovery/recycling from small equipment 

represent cost-effective options for reducing emissions from stationary equipment worldwide. For 

MVACs, the enhanced HFC-134a option represents the most cost-effective alternative for reducing 

emissions. 

IV.2.6 References 

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Exposure Values. Cincinnati, OH.

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Bennett, C. 2000. Personal communication between C. Bennett, Senior Vice President of Althoff 

Industries, Inc., and ICF Consulting. December 14, 2000. 

Calm, J. 1999. Emissions and Environmental Impacts from Air-Conditioning and Refrigeration Systems. 

Joint IPCC/TEAP Expert Meeting on Options for the Limitation of Emissions of HFCs and PFCs. 

Calm, J.M., D.J. Wuebbles, and A.K. Jain. 1999. Impacts on Global Ozone and Climate from Use and 

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China Association of Automobile Manufacturers. 2005. Workshop on Technology Cooperation for Next 

Generation Mobile Air Conditioning, 3-4 March 2005, New Delhi, India. 

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<http://www.contractingbusiness.com/editorial/serviceclinic/reclaim.cfm>. As obtained on July 7, 

2003. 
SECTION IV — INDUSTRIAL PROCESSES • REFRIGERATION AND AIR-CONDITIONING 

IV-56 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

Cooper, P.J. 1997. Experience with Secondary Loop Refrigeration Systems in European Supermarkets. 

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for Responsible Atmospheric Policy. November. 

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Options for the Limitation of Emissions of HFCs and PFCs held in the Netherlands. 

Crawford, J. March 2000. Review comments on the draft report, U.S. High GWP Gas Emissions 1990-2010: 

Inventories, Projections, and Opportunities for Reductions [Refrigeration and Air-Conditioning Chapter]. The 

Trane Company. 

Crawford, J. 2002. Refrigerant Options for Air Conditioning. Presented at the Earth Technologies Forum. 

The Alliance for Responsible Atmospheric Policy. March 26, 2002. 

Digmanese, T. 2004. Peer review comments on the USEPA Draft Report, DRAFT Analysis of International 

Costs of Abating HFC Emissions from Refrigeration and Air-Conditioning. York International Corporation. 

March 19, 2004. 

European Commission (EC). 2003. How to Considerably Reduce Greenhouse Gas Emissions Due to Mobile Air 

Conditioners Consultation paper from the European Commission Directorate-General Environment. 

February 4, 2003. 

EC (European Commission). 2004. Climate Change: Commission Welcomes Political Agreement In The Council 

To Reduce Emissions Of Fluorinated Greenhouse Gases. Press release issued on October 14, 2004. 

Available at <http://europa.eu.int/rapid/pressReleasesAction.do?reference=IP/04/1231&format= 

HTML&aged=0&language=EN&guiLanguage=fr>. As obtained on January 16, 2004. 

Environment Canada. 1998. Powering GHG Reductions Through Technology Advancement. pp.185-188. 

Environment Canada, Clean Technology Advancement Division. 

Faramarzi, R. and D. Walker. 2003. Field Evaluation of Secondary Loop Refrigeration for Supermarkets. 

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Society of Heating, Refrigerating, and Air-Conditioning Engineers, Inc. 

Fisher, S.K., J.J. Tomlinson, and P.J. Hughes. 1994. Energy and Global Warming Impacts of Not-in-Kind and 

Next Generation CFC and HCFC Alternatives. Prepared for the Alternative Fluorocarbons 

Environmental Acceptability Study and U.S. Department of Energy. Oak Ridge National Laboratory. 

Gaslok. 2002. Gaslok Flyer. Submitted electronically to ICF Consulting by David Peall. Gaslok. Available 

at <http://www.gaslok.net/>. 

Geoexchange. 2000. Information on geothermal heat pumps. Available at <http://www.geoexchange.org>. 

Greenchill. March 18, 2000. Fire and Ice. Sydney Morning Herald. Available at <http://www.greenchill.org/ 

sydneyhe.htm>. 

Greenpeace. December 5-7, 2001. Major Japanese Refrigerator Manufacturers to Produce Hydrocarbon Fridges 

for Japanese Market in 2002. A Greenpeace position paper prepared for the 35th Meeting of the 

Multilateral Fund for the Implementation of the Montreal Protocol in Montreal, Canada. 

Hill, W., and W. Atkinson. October 28, 2003. Peer review comments on the USEPA Draft Report, DRAFT 

Analysis of International Costs of Abating HFC Emissions from Refrigeration and Air-Conditioning. General 

Motors Corporation and Sun Test Engineering. 

HyChill. 2004. The Case for Hydrocarbons. Available at <http://www.hychill.com/>. 

Hydro Cool Online. 2002. Cool Technologies: Working Without HFCs. Updated June 2002. Available at 

<http://www.hydrocoolonline.com/news.php?n=LN009>. 

ICF Consulting. 2002a. Analysis on Combined Global Emission Estimates Scenarios. Deliverable submitted by 

ICF Consulting to the USEPA that included a revised analysis of the estimated level of recycling in 

other countries. Delivered to Casey Delhotal, Dave Godwin, and Debbie Ottinger of the USEPA 

Office of Atmospheric Programs. 

ICF Consulting. 2002b. ODS Destruction Report. Revised draft report submitted to Julius Banks of the 

USEPA Global Programs Division. 
SECTION IV — INDUSTRIAL PROCESSES • REFRIGERATION AND AIR-CONDITIONING 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES IV-57

International Energy Agency (IEA). 2003. “IEA Annex 26: Advanced Supermarket Refrigeration/Heat 

Recovery Systems, Final Report Volume 1—Executive Summary.” Compiled by Van D. Baxter, Oak 

Ridge National Laboratory. 

Intergovernmental Panel on Climate Change/Technical and Economic Assessment Panel (IPCC/TEAP). 

2005. IPCC/TEAP Special Report on Safeguarding the Ozone Layer and the Global Climate System: Issues 

Related to Hydrofluorocarbons and Perfluorocarbons. In B. Metz, L. Kuijpers, S. Solomon, S.O. Andersen, 

O. Davidson, J. Pons, et al (Eds.). Prepared by Working Groups I and III of the IPCC, and the TEAP. 

Cambridge University Press.

Japan Times. March 19, 2002. Hydrocarbon Fridges Hit Environment-Savvy Japan. 

Kruse, H. 1996. The State of the Art of Hydrocarbon Technology in Household Refrigeration. Proceedings 

of the International Conference on Ozone Protection Technologies. pp. 179-188. The Alliance for 

Responsible Atmospheric Policy. 

Kuijpers, L. March 28, 2002. Refrigeration Sector Update. Presented at the 19th Meeting of the Ozone 

Operations Resource Group (OORG), The World Bank. 

Lambertsen, C. J. 1971. Therapeutic Gases: Oxygen, Carbon Dioxide, and Helium. In J.R. DiPalma (Ed.), 

Drill’s Pharmacology in Medicine. New York: McGraw-Hill. 

Lundberg, E. July 9-11, 2002. An Enhanced R-134a Climate System. Presented at the 2002 SAE 

Automotive Alternative Refrigerant Systems Symposium in Scottsdale, AZ. Society of Automotive 

Engineers. 

OPROZ (Oficina Programa Ozono [Ozone Program Office]). February 2001. Report on the Supply and 

Consumption of CFCs and Alternatives in Argentina. 

Paul, J. October 1996. A Fresh Look at Hydrocarbon Refrigeration: Experience and Outlook. Proceedings 

of the International Conference on Ozone Protection Technologies. pp. 252-259. The Alliance for 

Responsible Atmospheric Policy. 

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<http://geoheat.oit.edu/bulletin/bull19-1/art62.htm>. 

Rawlings, P. 2000. Personal communication between P. Rawlings of the Geothermal Heat Pump 

Consortium and ICF Consulting. December 8, 2000. 

Refrigeration Technical Options Committee (RTOC). 2003. 2002 Report of the Refrigeration, Air Conditioning 

and Heat Pumps Technical Options Committee: 2002 Assessment. Section 8.4.2.7. 

Rugh, J., and V. Hovland. July 17, 2003. National and World Fuel Savings and carbon dioxide Emission 

Reductions by Increasing Vehicle Air Conditioning COP. Presented by John Rugh and Valerie 

Hovland of the National Renewable Energy Laboratory at the SAE 2003 Automotive Alternate 

Refrigerant Systems Symposium in Phoenix, AZ. Society of Automotive Engineers. 

Sand, J.R., S.K. Fischer, and V.D. Baxter. 1997. Energy and Global Warming Impacts of HFC Refrigerants and 

Emerging Technologies. Prepared for the Alternative Fluorocarbons Environmental Acceptability Study 

and U.S. Department of Energy. Oak Ridge National Laboratory. 

SKF. 2003. Hybrid bearings in oil-free air conditioning and refrigeration compressors. Evolution. SKF’s 

business and technology magazine. Available at <http://evolution.skf.com/gb/article. 

asp?articleID=410>. 

Smithart, G. October 17, 2003. Peer review comments on the USEPA Draft Report, DRAFT Analysis of 

International Costs of Abating HFC Emissions from Refrigeration and Air-Conditioning. Turbocor Inc. 

Society of Automotive Engineers (SAE). July 14, 2003a. Alternative Refrigerants Assessment Workshop. 

Presented at the 2003 Conference on Mobile Air Conditioning Technologies in Phoenix, AZ. 

Society of Automotive Engineers (SAE). July 15, 2003b. SAE Alternate Refrigerant Cooperative Research 

Project: Project Overview. Slide presentation given by Ward Atkinson at the 2003 Conference on 

Mobile Air Conditioning Technologies in Phoenix, AZ. 
SECTION IV — INDUSTRIAL PROCESSES • REFRIGERATION AND AIR-CONDITIONING 

IV-58 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

Society of Indian Automobile Manufacturers (SIAM). March 3–4, 2005. Growth and Projects of Automobile 

Industry and Mobile Air Conditioning, Workshop on Technology Cooperation for Next-Generation 

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India. 

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Force. 

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Retail Prices of Electricity, 1960-2004, and Table 11.8 on Retail Motor Gasoline Prices in Selected Countries, 

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U.S. Environmental Protection Agency (USEPA). 1993. Protection of Stratospheric Ozone; Refrigerant 

Recycling, Final Rule. Federal Register citation 58 FR 28660. USEPA. 14 May 1993. Available at 

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Supermarket Systems. EPA-600/R-97-039. Prepared by Eugene F. Troy of ICF Consulting for USEPA. 

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Inventories, Projections, and Opportunities for Reductions. EPA #000-F-97-000. U.S. Environmental 

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Society of Automotive Engineers Automotive Alternative Refrigerant Systems Symposium in 

Scottsdale, AZ. 
SECTION IV — INDUSTRIAL PROCESSES • SOLVENTS 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES IV-59

IV.3 HFC, HFE, and PFC Emissions from Solvents 

IV.3.1 Introduction 

DSs have been used as solvents in a wide range of cleaning applications, including precision, 

electronics, and metal cleaning (UNEP, 1999a). CFCs (in particular CFC-113), methyl 

chloroform (1,1,1-trichloroethane or TCA), and to a lesser extent, carbon tetrachloride (CCl4), 

were historically used as solvents in the United States. Similar usage occurred elsewhere, except in India 

and China, where greater volumes of CCl4 were consumed. 

To comply with the requirements of the Montreal Protocol,1 many countries started using HCFCs, 

and aqueous and semiaqueous not-in-kind (NIK) solvents, as substitutes for ODSs. For example, the 

majority of metal cleaning end-users and some of the electronics and precision cleaning solvent end-users 

have already transitioned to no-clean, semiaqueous cleaning, and aqueous cleaning alternative methods. 

Many of the in-kind replacement solvents, including HFCs and PFCs, have also taken a share of the 

substitute market because they have high reliability, excellent compatibility, good stability, low toxicity, 

and selective solvency. These HFCs and PFCs have 100-year GWPs ranging from 890 to 7,4002

 and 

relatively low boiling points (50°C to 90°C) that contribute to their inadvertent release to the atmosphere. 

The replacement solvent technologies used globally are summarized in Table 3-1. 

HFC solvents include HFC-4310mee, HFC-365mfc, and HFC-245fa. Of these HFCs, HFC-4310mee is 

the most common solvent cleaner replacement. HFC-365mfc is used as an additive to form solvent blends 

with HFC-4310mee, helping to reduce the cost of these products (Micro Care, 2002). HFC-245fa is used in 

the aerosol solvent industry (Honeywell, 2003). Heptafluorocyclopentane is another HFC that could be 

used, although it is not yet used in significant amounts. Certain solvent applications, particularly 

precision cleaning end-uses, will continue to use HCFCs, especially HCFC-225ca/cb (until the HCFC 

phaseout takes place), and to a much lesser extent, PFCs and perfluoropolyethers (PFPEs). 

This report analyzes three solvent end-uses: metal, precision, and electronics cleaning. Metal cleaning 

involves the removal of contaminants such as oils, greases, and particulate matter from metal surfaces 

during the production of metal parts and the maintenance and repair of equipment and machinery. 

Electronics cleaning, or defluxing, consists mainly of removing flux residue that remains after a soldering 

operation for printed circuit boards and other contamination-sensitive electronics applications. Precision 

cleaning may apply to either electronic components or to metal surfaces and is characterized by products 

that require a high level of cleanliness and generally have complex shapes, small clearances, and other 

cleaning challenges (UNEP, 1999a). Examples of applications and products requiring precision cleaning 

include disk drives, gyroscopes, medical devices, and optical components. Based on current 

understanding of market trends, HFC emissions from the precision and electronics cleaning end-uses 

dominate the GWP-weighted emissions from the solvents sector. The metal cleaning 

 

1

 Parties to the Montreal Protocol on Substances that Deplete the Ozone Layer (Montreal Protocol) agreed to phase out 

consumption of all ODSs, including those used as solvents. In developed countries, the solvent industry has phased 

out its use of Class I ODSs (in particular CFCs and 1,1,1-trichloroethane). Developing countries are scheduled to 

phase out these substances between 2008 and 2010. 

2 7,400 is the GWP of perfluorohexane (C6F14), and is used in this report for estimating purposes as the GWP for 

PFC/PFPEs. 

O 
SECTION IV — INDUSTRIAL PROCESSES • SOLVENTS 

IV-60 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

Table 3-1: General Overview of Solvent Technologies Used Globally 

Solvent Classes Metal Electronics Precision 

Chlorinated solvents X X X 

HCFC solvents (HCFC-225 ca/cb and HCFC-141b) X X 

HFC solvents (primarily HFC-4310mee) X X 

PFC solvents X X 

Hydrofluoroether (HFE) solvents X X 

Hydrocarbons X X X 

Alcohol solvents X X X 

Brominated solvents X X X 

Methyl siloxanes X X X 

Alternative Cleaning Technologies

Aqueous cleaning X X X 

Semiaqueous cleaning X X X 

No-clean processes X Xa

a For electronics cleaning, no-clean processes include low-solids flux or paste and inert gas soldering. 

end-use has primarily transitioned away from ODSs directly into alternatives or processes that do not use 

high-GWP chemicals. 

IV.3.2 Baseline Emissions Estimates 

IV.3.2.1 Emissions Estimating Methodology 

Description of Methodology 

Specific information on how the model calculates solvent emissions is described below. 

The USEPA uses a detailed Vintaging Model of ODS-containing equipment and products to estimate 

the use and emissions of various ODS substitutes in the United States, including HFCs and PFCs. 

Emissions baselines from non-U.S. countries were derived using country-specific ODS consumption 

estimates as reported under the M ontreal Protocol,in conjunction with Vintaging Model output 

for each ODS-consuming end-use sector. For sectors where detailed information was available, these data 

were incorporated into country-specific versions of the Vintaging Model to customize emission estimates. 

In the absence of country-level data, these preliminary estimates were calculated by assuming that the 

transition from ODSs to HFCs and other substitutes follows the same general substitution patterns 

internationally as observed in the United States. From this preliminary assumption, emissions estimates 

were then tailored to individual countries or regions by applying adjustment factors to U.S. substitution 

scenarios, based on relative differences in (1) economic growth, (2) rates of ODS phaseout, and (3) the 

distribution of ODS use across end-uses in each region or country. 

Emissions Equations 

Generally, the emissions model assumes that some portion of used solvent remains in the liquid 

phase and is not emitted as gas. Thus, emissions are considered incomplete and are set as a fraction of the 

amount of solvent consumed in a year. For solvent applications, a fixed percentage of the new chemical 

used in equipment is assumed to be emitted in that year, with the remainder of the used solvent reused 
SECTION IV — INDUSTRIAL PROCESSES • SOLVENTS 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES IV-61

or disposed of without being released to the atmosphere. The following equation calculates emissions 

from solvent applications: 

 Ej = L * Qcj (3.1) 

where 

Ej = Total emissions of a specific chemical in a given year j from use in solvent applications, by 

weight. 

L = The percentage of the total chemical that is lost to the atmosphere, assumed to be 90 percent. 

Qcj = Total quantity of a specific chemical sold for use in solvent applications in the given year j, by 

weight. 

j = Year of emissions. 

Many solvent users have added emissions control features to their equipment, resulting in lower 

solvent consumption. Eventually, almost all of the solvent consumed in a given year is emitted, because 

the solvent is continuously reused through a distilling and cleaning process or through recycling, while a 

small amount of solvent is disposed with the sludge that remains. The model used for this analysis 

assumes that 90 percent of the solvent consumed annually is emitted to the atmosphere. 

Regional Variations and Adjustments 

The following adjustment factor assumptions, specific to the solvent sector, were used to customize 

the global emissions estimating methodology, described above, for solvents: 

• PFC/PFPE solvents were assumed to be used in countries with significant annual output from the 

electronics industry. Global PFC usage for solvent cleaning was geographically distributed using 

the semiconductor industry as a proxy; specifically, data on the share of world silicon wafer starts 

per month (8-inch equivalent) (SEMI International, 2003) were used. PFC/PFPE solvent use was 

assumed to be discontinued by 2010 in the United States and by 2015 in other countries. 

• Emissions in EU-15 countries were assumed to equal only 80 percent of the preliminary estimate 

to reflect that NIK technology has taken a more significant market share in European countries 

(ECCP, 2001). Consequently, the resulting EU emissions estimate was reduced by 20 percent. 

• A 50-percent adjustment factor was applied to countries with CEITs, European countries that are 

not members of the EU-15, and developing (non-Annex I) countries. For these countries, the 

primary barriers to the transition from ODS solvents to fluorinated solvents has been the high 

cost of HFC-4310mee and the lack of domestic production (UNEP, 1999a; UNEP, 1999b). 

IV.3.2.2 Baseline Emissions 

Table 3-2 presents total HFC, PFC, and HFE emissions estimates in MtCO2eq for the solvent sector. In 

the United States, HFC-4310mee is responsible for the majority of the country’s projected ODS substitute 

solvent emissions, whereas PFC/PFPE emissions are assumed to decline linearly until they are 

discontinued completely in 2010. U.S. emissions reflect the continued decline of PFC/PFPE consumption 

as a result of restrictions enforced by the USEPA’s Significant New Alternatives Policy Program, which 

limits PFC and PFPE use to only those applications where these solvents have been deemed necessary to 

meet performance or safety requirements. U.S. solvent end-users that have historically used PFC/PFPEs 

are turning to other solvents, including HFC-4310mee. 
SECTION IV — INDUSTRIAL PROCESSES • SOLVENTS 

IV-62 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

Table 3-2: Total Baseline HFC, PFC, and HFE Emissions Estimates from Solvents (MtCO2eq) 

Region 2000 2010 2020 

Africa 0.0 0.0 0.0 

Annex I 10.0 5.4 4.1 

Australia/New Zealand 0.2 0.1 0.1 

Brazil 0.0 0.1 0.1 

China 4.0 1.4 0.1 

Eastern Europe 0.1 0.0 0.0 

EU-15 3.7 2.1 0.9 

India 0.0 0.0 0.0 

Japan 3.5 1.4 0.9 

Mexico 0.0 0.0 0.0 

Non-OECD Annex I 0.0 0.0 0.0 

OECD 11.6 5.9 4.1 

Russian Federation 0.0 0.0 0.0 

South & SE Asia 2.3 0.8 0.2 

United States 2.4 1.7 2.0 

World Total 16.4 7.7 4.5 

EU-15 = European Union; OECD = Organisation for Economic Co-operation and Development. 

Similarly, some PFC use for precision and electronics cleaning in countries outside the United States 

was assumed to decline linearly until use is discontinued completely in 2015. Global PFC use for solvent 

cleaning, as provided by industry expert opinion, was apportioned to non-U.S. countries using the global 

distribution of the semiconductor market as a proxy for circuit board cleaning, a predominant electronics 

cleaning end-use (3M Performance Materials, 2004; DuPont FluoroProducts, 2004; SEMI International, 

2003). 

Figure 3-1 displays total HFC, PFC, and HFE emission estimates for the solvent sector by region from 

1990 to 2020. 

IV.3.3 Cost of HFC, HFE, and PFC Emissions Reductions for Solvents 

This section presents a cost analysis for achieving HFC, HFE, and PFC emissions reductions from the 

emissions baselines presented in Table 3-2 above. All cost analyses for the solvent emissions reduction 

options assume a 10-year project lifetime. Each abatement option is described below. 

IV.3.3.1 Description and Cost Analysis of Abatement Options 

Some HFC, HFE, and PFC emissions from the solvent sector can be eliminated or mitigated through 

several technologies and practices. Emissions and use of these compounds can be reduced by retrofitting 

equipment and improving containment of the solvents, introducing carbon adsorption technologies, and 

replacing outdated equipment with more modern technologies. Additionally, NIK technologies and 

processes already used in many solvent markets worldwide employ semiaqueous, aqueous, or no-clean 

methods in place of solvents. Ongoing research continues to identify low-GWP alternatives, including 

low-GWP HFCs and HFEs that could replace high-GWP PFCs and HFCs. Some alternative solvent 

cleaning approaches use other organic solvents, including chlorinated solvents, alcohols, petroleum 

distillates, and aliphatic solvents. 
SECTION IV — INDUSTRIAL PROCESSES • SOLVENTS 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES IV-63

Figure 3-1: Total Baseline HFC, PFC, and HFE Emissions Estimates from Solvents (MtCO2eq) 

CPA = Centrally Planned Asia; Non-EU FSU = non-European Union Former Soviet Union; OECD = Organisation for Economic Co-operation 

and Development. 

Flammable organic solvent alternatives, such as ketones, ethers, and alcohols, can also potentially 

replace HFCs, HFEs, and PFCs. Because these alternatives are fairly aggressive and would have different 

materials compatibility issues than the fluorinated solvents, and because limited technical and cost 

information is available on fire suppression equipment, explosion-proof wiring, and other workplace 

controls, these additional alternatives are not addressed further in this analysis. 

Three potential mitigation options are identified and analyzed in this report: 

• conversion to HFE solvents, 

• improved equipment and cleaning processes using existing solvents (retrofit), and 

• aqueous and semiaqueous NIK replacement alternatives. 

The remainder of Section IV.3.3 describes each of these options in detail and provides a discussion of 

associated cost and emissions reduction estimates. A detailed description of the cost and emissions 

reduction analysis for each option can be found in the Appendix G for this chapter. 

Conversion to HFE Solvents 

HFC and PFC solvents can be replaced by alternative organic solvents with lower GWPs, which are 

making headway in the market. These alternative solvents include low-GWP HFCs and HFEs, 

hydrocarbons, alcohols, volatile methyl siloxanes, brominated solvents, and non-ODS chlorinated 

solvents. For the purpose of this analysis, commercially available HFE-7100 and HFE-7200 are used as 

proxies for the alternative solvent abatement option because they display material compatibility 

properties similar to HFCs and PFCs, a prime factor that has led to their current success in the market. 

Specifically, HFEs have replaced PFCs, CFC-113, 1,1,1-trichloroethane, HFCs, and HCFCs in certain 

precision cleaning operations. Many solvent users have successfully transitioned from PFC solvents to 

HFC-4310mee and HFEs in cleaning applications such as computer disk lubrication, particulate cleaning, 
SECTION IV — INDUSTRIAL PROCESSES • SOLVENTS 

IV-64 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

and cleaning of electronic assemblies after soldering. HFEs and azeotropes of HFEs are also viable 

replacements for HFC-4310mee in certain precision and electronics cleaning operations. 

Because PFCs are specific to a small portion of the global solvent market, and because they are likely 

to be more expensive than HFCs, costs for this analysis are calculated based on a transition from HFC4310mee to HFEs, rather than from PFCs to HFEs. Additionally, many users are switching from PFCs to 

HFC-4310mee. Since this transition is assumed to occur in the baseline, the transition is not quantified as 

an option for further reductions. Therefore, PFC solvent users that switch directly to HFEs may 

experience a cost savings compared with HFC solvent users switching to HFEs. 

For the purpose of this analysis, the 100-year GWP of alternative solvents reflects the market presence 

of two HFEs. HFE-7100, which has a GWP of 390, is assumed to represent 75 percent of the market, and 

HFE-7200, which has a GWP of 55, is assumed to represent the remaining 25 percent. The GWP of the 

solvent being replaced, HFC-4310mee, is 1,300.3 Because of the lower average GWP, this option has a 

reduction efficiency of 76.4 percent (i.e., the difference of the GWP of HFC-4310mee and the weighted 

average of the HFE GWPs, divided by the GWP of HFC-4310mee). This analysis assumes that the 

technical applicability4 of this option is 81 percent of total solvent emissions for each region in 2005, 

dropping to 79 percent from 2010 through 2020 (Table 3-4). 

HFE solvents are gaining acceptance in U.S. industry because of their availability, safety, and 

effectiveness (Salerno, 2001); however, some uncertainty exists regarding the likelihood and ease with 

which HFC-4310mee users will convert to an HFE-alternative solvent because of application-specific 

requirements (UNEP, 1999b). The incremental maximum market penetration of this option in the United 

States is assumed to increase from 10 percent in 2005 to 60 percent in 2020, as shown in Table 3-4. 

For all other countries, the incremental maximum market penetration is assumed to increase from 5 

percent in 2005 to 25 percent in 2020, representing a slower adoption of this option and less reliance on 

the use of fluorinated compounds compared with the assumed scenario for the United States (see 

Table 3-4). This assumption is based on current market data, which indicates that HFE solvents are 

available and being used in the same regions where HFC solvents are being used (3M Performance 

Materials, 2003). 

Improved Equipment and Cleaning Processes Using Existing Solvents (Retrofit)

HFCs, HFEs, and PFCs are more expensive than historically used solvents such as CFC-113 and 

HCFC-141b. Attempts to reduce emissions, and hence save costs, have led to significant improvements in 

degreasing, defluxing, and other cleaning equipment containment technologies. Engineering control 

changes (e.g., increased freeboard height, installation of freeboard chillers, and use of automatic hoists), 

improved containment, and implementation of other abatement technologies can reduce emissions of 

HFCs, HFEs, and PFCs used in solvent cleaning (UNEP, 1999a; ICF Consulting, 1992). For example, some 

cleaning equipment that uses HFC solvents is being retrofitted with higher freeboard height and lowtemperature secondary cooling coils. It is also possible to keep emissions at a minimum by using good 

 

3 Although the GWP value for HFC-4310mee was taken from the IPCC Second Assessment Report (1996), the report did 

not provide GWP values for either HFE. Consequently, this analysis uses the GWP values listed in the IPCC Third 

Assessment Report (2001) for both HFEs. The GWPs of HFEs are still being studied; for instance, some analyses show 

the GWP of HFE-7100 to be approximately 300 (3M Performance Materials, 2003). 

4 In this report, the term “technically applicable” refers to the emissions to which an option can theoretically be 

applied. Because HFEs can be substituted for HFCs and PFCs, HFEs are technically applicable to all HFC and PFC 

solvent emissions, but they are not technically applicable to HFE baseline emissions. Other factors will affect the 

application of HFCs and PFCs, and the market penetration assumed in this analysis. 
SECTION IV — INDUSTRIAL PROCESSES • SOLVENTS 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES IV-65

handling practices, such as reducing systems’ solvent drag-out losses by keeping the workload in the 

vapor zone long enough to drain and dry any entrapped or remaining solvent (UNEP, 1999a; Petroferm, 

2000). One can also minimize evaporative losses by improving the design of solvent bath enclosures and 

vapor recovery condensing systems (March Consulting Group, 1998 and 1999). 

As shown in Table 3-3, retrofitting a vapor degreaser with an open-top area of 13 square feet, 

combined with proper operation and maintenance, can reduce solvent emissions by as much as 46 to 70 

percent, depending on the specific retrofit methods chosen (Durkee, 1997). For example, installing a 

freeboard refrigeration device, sometimes referred to as a chiller (i.e., a set of secondary coils mounted in 

the freeboard), and maintaining a freeboard ratio of 1.0 to minimize diffusional solvent losses, can reduce 

emissions by 46 percent, while installing heating coils to produce superheated vapor along with installing 

a chiller can reduce emissions by 70 percent. For the purpose of this analysis, the reduction efficiency of 

the retrofit option is assumed to equal 70 percent, which can be achieved at a one-time cost of $16,800 (see 

Table 3-3). 

Table 3-3: Retrofit Techniques for Batch Vapor Cleaning Machine (Less than 13 Square Feet) 

Retrofit Technique Reduction Efficiency (%) One-Time Cost (2000$) 

Freeboard ratio of 1.0, freeboard refrigeration device 46.0% $11,200 

Working mode cover, freeboard refrigeration device 64.0% $15,800 

Superheated vapor, freeboard refrigeration device 70.0% $16,800 

Source: Durkee, 1997. 

Retrofits to vapor degreasing machines larger than 13 square feet cost more but can achieve emissions 

reduction efficiencies as high as 85 percent. Furthermore, for larger operations where there is more than 

one vapor degreaser, retrofit methods, such as installing a carbon adsorber, can be implemented to 

capture solvent vapor from the air for the entire facility. The reduction efficiency of a carbon adsorber 

combined with the installation of heating coils and chillers has been estimated at 88 percent for larger 

(i.e., greater than 13 square feet) vapor degreasers (Durkee, 1997). 

In the United States, many enterprises have bought new equipment or retrofitted aging equipment 

into compliance with the National Emissions Standard for Hazardous Air Pollutants (NESHAP), which 

limits emissions from degreasers using traditional chlorinated solvents such as trichloroethylene. 

Fluorinated solvents such as HFCs are not covered by this regulation; nonetheless, a number of 

companies using HFCs and other nonchlorinated solvents have adopted NESHAP-compliant solvent 

cleaning machines because of the associated economic, occupational, and environmental benefits 

(Durkee, 1997). Consequently, end-users in the United States are not expected to benefit from this option 

in the future. Thus, this analysis assumes that the incremental maximum market penetration will drop 

from 5 percent in 2005, to zero in 2010 through 2020 (i.e., by 2010 and beyond, the solvent equipment in 

use will either already be retrofitted or will not require retrofitting, and the resulting lower emissions are 

already incorporated into the baseline). The resulting maximum market penetrations are shown in 

Table 3-4. 

Likewise, many European countries have imposed stringent environmental and safety regulations 

that require the lowest level of emissions attainable by solvent degreasing equipment. Retrofit techniques 

were either already implemented or simply not required if the user had purchased new emission-tight 

vapor degreasers. Therefore, for non-U.S. Annex I countries, the maximum market penetration for this 

option is also assumed to be 5 percent in 2005, dropping to zero by 2010. 
SECTION IV — INDUSTRIAL PROCESSES • SOLVENTS 

IV-66 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

This analysis assumes that most solvent users in non-Annex I (i.e., developing) countries may 

consider the equipment retrofit option, because updating their equipment may be preferred over 

investing in entirely new units. Consequently, this region is assumed to adopt these techniques slowly, 

such that 5 percent of the market will have adopted this option by 2005. Adoption is assumed to increase 

at a slow, steady rate to 15 percent in 2020 (see Table 3-4). 

Aqueous and Semiaqueous NIK Replacement Alternatives 

In addition to the emissions reduction approaches that use a combination of improved equipment 

and cleaning practices, NIK technology processes and solvent replacements can be used to substitute for 

PFC-, HFC-, and HFE-containing systems. In the aqueous process, a water-based cleaning solution is 

used as the primary solvent and is usually combined with a detergent to remove contaminants. In the 

semiaqueous process, the cleaning solution is an organic solvent that is blended with a surfactant, making 

it water soluble. An example of a solvent/surfactant blend is a terpene/water combination blended with 

glycol ethers (UNEP, 1999a). The reduction efficiency of NIK abatement options is assumed to be 100 

percent because the HFC or PFC solvent is completely replaced by water and an organic solvent, 

combinations of which have low to no GWP. 

Many electronics, metal, and precision cleaning end-users have already switched to aqueous and 

semiaqueous NIK cleaning methods. Both NIK processes have proven very successful for large-scale 

metal cleaning, where equipment and wastewater treatment costs are of less concern because of the large 

volumes processed (UNEP, 1999a). Aqueous cleaning technologies have been available and widely used 

for over 25 years and have replaced many electronics cleaning solvent systems in developed countries 

(Chaneski, 1997; UNEP, 1999a). Semiaqueous cleaning has also been available for years but has lost much 

of its initial promise in many developed nations for the cleaning of electronic assemblies because of the 

additional complexity and subsequent expense associated with the cleaning process, which includes more 

steps than aqueous cleaning (UNEP, 1999a). 

Because the NIK options are applicable to both the electronic and precision cleaning end-uses, the 

NIK options are assumed to be applicable to 100 percent of high-GWP solvent emissions, resulting in a 

technical applicability of 100 percent for all regions (see Table 3-4). The assumed market penetration, 

however, is lower, as explained below. 

Technical limitations of NIK technologies arising from issues such as substrate corrosion or 

inadequate performance for applications with complex parts can lead to reduced market acceptability. 

The U.S. incremental maximum market penetrations for these options are assumed to be smaller than in 

other regions, to reflect the belief that the U.S. market will likely prefer fluorinated solvents such as HFCs 

and HFEs (see Table 3-4). The market penetrations are also assumed to be smaller because most 

operations that can use aqueous and semiaqueous technologies are doing so already. For non-U.S. Annex 

I and non-Annex I regions, the maximum market penetrations of these two NIK options are assumed to 

be similar to each other from 2005 to 2020. NIK alternatives are currently gaining market share in 

European countries, a trend that is assumed to continue for this region (ECCP, 2001). 

Some developing countries are also assumed to prefer NIK technologies because of their perceived 

low costs. Aqueous cleaning is popular in China, for example, because of the small cost per kilogram of 

the nonfluorinated cleaning chemicals used, despite newly introduced costs such as wastewater 

treatment. Conversely, the availability of water, the costs associated with energy to dry the product, and 

local wastewater treatment regulations can discourage companies in developing regions of the world 

from considering this option (UNEP, 2003). For all regions, the semiaqueous option is assumed to have 

slightly smaller market penetrations than the aqueous cleaning option. 
SECTION IV — INDUSTRIAL PROCESSES • SOLVENTS 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES IV-67

IV.3.3.2 Summary of Technical Applicability, Market Penetration, and Costs of 

Abatement Options 

Table 3-4 summarizes the technical applicability and the maximum market penetration of the solvent 

options presented in the discussions above. By 2020, it is assumed that the NIK replacement option can be 

applied to 15 percent of the baseline solvent emissions in the United States, 30 percent of the baseline 

solvent emissions in the Annex I countries, and 30 percent of the baseline solvent emissions in non-Annex 

I countries. By 2020, the retrofit option is assumed to be viable only in non-Annex I countries. In addition, 

the conversion to HFE solvents option can be applied to the baseline HFC and PFC emissions, as shown 

below. 

Table 3-4: Technical Applicability and Incremental Maximum Market Penetration of Solvent Options 

(Percent)aUnited States 

Non-U.S. Annex I Non-Annex I United States Non-U.S. Annex I Non-Annex I United States Non-U.S. Annex I Non-Annex I United States Non-U.S. Annex I Non-Annex I United States Non-U.S. Annex I Non-Annex I 

Market Penetration 

Option 

Technical 

Applicability 

(All Years)b 2005 2010 2015 2020 

Retrofit 100% 100% 100% 5% 5% 5% 0% 0% 8% 0% 0% 12% 0% 0% 15% 

Conversion to HFE 

solvents 

79–

81% 

79–

81% 

79–

81% 

10% 5% 5% 30% 10% 10% 45% 15% 15% 60% 25% 25% 

NIK replacements 100% 100% 100% 4% 8% 8% 8% 15% 15% 12% 23% 23% 15% 30% 30% 

Semiaqueous 100% 100% 100% 1% 3% 3% 3% 5% 5% 4% 8% 8% 5% 10% 10% 

Aqueous 100% 100% 100% 3% 5% 5% 5% 10% 10% 8% 15% 15% 10% 20% 20% 

a Assumed maximum market penetration of options is presented as a percentage of total sector emissions for which the options are technically 

applicable. The baseline market penetration is assumed to be zero to assess the emissions reductions possible due to increased use of each 

option. 

b The percentage of total emissions represented by HFEs varies by year. The technical applicability is 81 percent in 2005, and 79 percent in 

2010 through 2020. 

To calculate the percentage of emissions reductions off the total solvent baseline for each abatement 

option, the technical applicability (Table 3-4) is multiplied by the market penetration value (Table 3-4) 

and by the reduction efficiency of the option. For example, to determine the percentage reduction off the 

2020 baseline for the “conversion to HFE solvents” option in the United States, the following calculation 

is performed: 

Technical applicability x Market penetration in 2020 x Reduction efficiency = 

79.0% x 60.0% x 76.4% ≈ 36.2% 

Thus, using the assumptions in this analysis, converting to an HFE solvent could reduce 

approximately 36 percent of the U.S. emissions baseline in 2020. This figure, along with the other 

emissions reduction potentials, is shown in Table 3-5. 

Table 3-6 presents a summary of the cost assumptions used for the solvent options presented in the 

discussions above. 
SECTION IV — INDUSTRIAL PROCESSES • SOLVENTS 

IV-68 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

Table 3-5: Emissions Reductions Off the Total Solvent Baseline (Percent) United States Non-U.S. Annex I Non-Annex I United States Non-U.S. Annex I Non-Annex I United States 

Non-U.S. Annex I Non-Annex I United States Non-U.S. Annex I Non-Annex I 

Option 2005 2010 2015 2020 

Retrofit 3.5% 3.5% 3.5% 0.0% 0.0% 5.6% 0.0% 0.0% 8.4% 0.0% 0.0% 10.5% 

Conversion to HFE solvents 6.2% 3.1% 3.1% 18.1% 6.0% 6.0% 27.2% 9.1% 9.1% 36.2% 15.1% 15.1% 

NIK replacements 3.8% 7.5% 7.5% 7.5% 15.0% 15.0% 11.3% 22.5% 22.5% 15.0% 30.0% 30.0% 

Semiaqueous 1.3% 2.5% 2.5% 2.5% 5.0% 5.0% 3.8% 7.5% 7.5% 5.0% 10.0% 10.0% 

Aqueous 2.5% 5.0% 5.0% 5.0% 10.0% 10.0% 7.5% 15.0% 15.0% 10.0% 20.0% 20.0% 

Table 3-6: Summary of Abatement Option Cost Assumptions 

Option 

Time 

Horizon 

(Years) Unit of Costs 

Base OneTime Cost 

(2000$) 

Base 

Annual 

Cost 

(2000$) 

Base 

Annual 

Savings 

(2000$) 

Net Annual 

Costs 

(2000$/yr) 

Retrofit 10 Per degreaser with an 

open-top area 13 ft2

 $16,800 $0 $233,300 –$233,300 

NIK aqueous 10 Per standard 

degreaser unit 

 $80,000 $0 $0 $0 

NIK 

semiaqueous 

10 Per standard 

degreaser unit 

 $10,000 $0 $0 $0 

HFC to HFE 10 Per kilogram of 

solvent 

 $0 $0 $0 $0 

IV.3.4 Results 

IV.3.4.1 Data Tables and Graphs 

Tables 3-7 and 3-8 provide a summary of the potential emissions reduction opportunities at 

associated breakeven costs in 15-dollar increments at a 10 percent discount rate (DR) and 40 percent tax 

rate (TR). As shown, in 2010 and 2020, emissions reduction opportunities become available for regions 

such as Annex I and OECD at the lowest breakeven cost of $0/tCO2eq. For regions such as Mexico and the 

Russian Federation, emissions reduction opportunities are not available because emissions from the 

solvent sector are so minute for these regions. A world total emissions reduction of 1.83 MtCO2eq is 

projected by 2010 and 2.20 MtCO2eq by 2020, both at a breakeven cost of $15/tCO2eq. 

Table 3-9 presents the costs, in 2000$, to reduce 1 MtCO2eq for a discount rate scenario of 10 percent 

and a tax rate of 40 percent. The results are ordered by increasing costs per tCO2eq. Also presented are 

the emissions reduced by the option, in MtCO2eq and percentage of the solvents baseline, and cumulative 

totals of these two figures. 
SECTION IV — INDUSTRIAL PROCESSES • SOLVENTS 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES IV-69

Table 3-7: Country/Regional Emissions Reductions in 2010 and Breakeven Costs for Solvents at 10% 

Discount Rate, 40% Tax Rate ($/tCO2eq) 

2010 

Country/Region $0 $15 $30 $45 $60 >$60 

Africa 0.00 0.01 0.01 0.01 0.01 0.01 

Annex I 0.53 1.21 1.21 1.21 1.21 1.21 

Australia/New Zealand 0.00 0.02 0.02 0.02 0.02 0.02 

Brazil 0.01 0.01 0.01 0.01 0.01 0.01 

China 0.16 0.37 0.37 0.37 0.37 0.37 

Eastern Europe 0.00 0.01 0.01 0.01 0.01 0.01 

EU-15 0.13 0.45 0.45 0.45 0.45 0.45 

India 0.00 0.00 0.00 0.00 0.00 0.00 

Japan 0.08 0.29 0.29 0.29 0.29 0.29 

Mexico 0.00 0.00 0.00 0.00 0.00 0.00 

Non-OECD Annex I 0.00 0.00 0.00 0.00 0.00 0.00 

OECD 0.59 1.36 1.36 1.36 1.36 1.36 

Russian Federation 0.00 0.00 0.00 0.00 0.00 0.00 

South & SE Asia 0.03 0.07 0.07 0.07 0.07 0.07 

United States 0.30 0.43 0.43 0.43 0.43 0.43 

World Total 0.80 1.83 1.83 1.83 1.83 1.83 

EU-15 = European Union; OECD = Organisation for Economic Co-operation and Development. 

Table 3-8: Country/Regional Emissions Reductions in 2020 and Breakeven Costs for Solvents at 10% 

Discount Rate, 40% Tax Rate ($/tCO2eq) 

2020 

Country/Region $0 $15 $30 $45 $60 >$60 

Africa 0.01 0.02 0.02 0.02 0.02 0.02 

Annex I 1.05 1.96 1.96 1.96 1.96 1.96 

Australia/New Zealand 0.01 0.04 0.04 0.04 0.04 0.04 

Brazil 0.02 0.04 0.04 0.04 0.04 0.04 

China 0.03 0.06 0.06 0.06 0.06 0.06 

Eastern Europe 0.00 0.01 0.01 0.01 0.01 0.01 

EU-15 0.14 0.40 0.40 0.40 0.40 0.40 

India 0.00 0.00 0.00 0.00 0.00 0.00 

Japan 0.13 0.40 0.40 0.40 0.40 0.40 

Mexico 0.00 0.00 0.00 0.00 0.00 0.00 

Non-OECD Annex I 0.00 0.01 0.01 0.01 0.01 0.01 

OECD 1.07 2.01 2.01 2.01 2.01 2.01 

Russian Federation 0.00 0.00 0.00 0.00 0.00 0.00 

South & SE Asia 0.02 0.05 0.05 0.05 0.05 0.05 

United States 0.74 1.05 1.05 1.05 1.05 1.05 

World Total 1.16 2.20 2.20 2.20 2.20 2.20 

EU-15 = European Union; OECD = Organisation for Economic Co-operation and Development. 
SECTION IV — INDUSTRIAL PROCESSES • SOLVENTS 

IV-70 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

Table 3-9: World Breakeven Costs and Emissions Reductions in 2020 for Solvents 

Reduction 

Option 

Cost (2000$/tCO2eq) 

10% DR, 40% TR 

Emissions 

Reduction of 

Option 

(MtCO2eq) 

Reduction 

from 2020 

Baseline (%) 

Cumulative 

Reductions 

(MtCO2eq) 

Cumulative 

Reduction 

from 2020 

Baseline (%) 

Retrofit –$50.75 0.0454 1.0% 0.05 1.0% 

HFC to HFE $0.00 1.11 24.7% 1.16 25.7% 

NIK semiaqueous $0.67 0.35 7.7% 1.51 33.4% 

NIK aqueous $5.36 0.70 15.5% 2.20 48.9% 

Figures 3-2 and 3-3 display the solvent international marginal abatement curves (MACs) by region 

for 2010 and 2020, respectively. 

Figure 3-2: 2010 MAC for Solvents, 10% Discount Rate, 40% Tax Rate 

EU-15 = European Union; OECD = Organisation for Economic Co-operation and Development. 
SECTION IV — INDUSTRIAL PROCESSES x SOLVENTS 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES IV-71

Figure 3-3: 2020 MAC for Solvents, 10% Discount Rate, 40% Tax Rate 

EU-15 = European Union; OECD = Organisation for Economic Co-operation and Development. 

IV.3.4.2 Uncertainties and Limitations 

This section focuses on the uncertainties and limitations associated with the cost estimates presented 

in this analysis. One significant area of uncertainty is how capital costs for these mitigation technologies 

may vary internationally. The analysis is currently limited by the lack of this specificity on region-specific 

cost analysis estimates. In addition, the three abatement options identified in this analysis have the 

following uncertainties. 

Conversion to HFE Solvents 

Short- and long-term cost savings may occur with this option; yet because of their uncertainty, this 

analysis conservatively assumes no cost savings. 

Improved Equipment and Cleaning Processes Using Existing Solvents (Retrofit) 

The analysis does not realize any annual labor costs that may accompany the use of retrofitted 

equipment. These incurred costs may include training and frequent, mandatory maintenance checks. 

Aqueous and Semiaqueous NIK Replacement Alternatives 

The major uncertainties regarding this option are the annual costs and cost savings. Because cost 

savings, which may offset increased operating costs, are not quantified for this analysis, this analysis does 

not assume annual costs or cost savings for this option. 

IV.3.5 Summary 

Baseline global HFC, HFE, and PFC emissions from solvents are estimated to decline from 16.4 to 4.5 

MtCO2eq between 2000 and 2020. In 2020, Annex I countries are assumed to account for approximately 90 

percent of global emissions, with U.S. emissions assumed to account for half of emissions from Annex I 
SECTION IV — INDUSTRIAL PROCESSES • SOLVENTS 

IV-72 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

countries (Table 3-2). Projected growth in emissions (between 2010 and 2020) is expected to occur only in 

the United States, from 1.7 MtCO2eq in 2010 to 2.0 MtCO2eq in 2020. 

This analysis considers three emissions mitigation options for solvent use: (1) adoption of alternative, 

(HFE-7100 or HFE-7200) partially fluorinated solvents, (2) improved system design through retrofitting 

solvent processes, and (3) conversion to NIK (aqueous and semiaqueous replacements). The costs and 

emissions reduction benefits of each option were compared in each region (Tables 3-7 and 3-8). Globally, 

retrofitting represents the most cost-effective option for reducing HFC, HFE, and PFC emissions from the 

solvent sector, with a cost savings of $50.75 per tCO2eq at a 10 percent discount rate and 40 percent tax 

rate. Converting to an HFE solvent is a cost-neutral option for all regions. By 2020, 2.20 MtCO2eq, or 49 

percent of global baseline emissions from solvents, can be reduced at a cost under $10 per tCO2eq. 

For all three options, costs per tCO2eq for each region are equivalent because available data on costs 

for abatement technologies were not scaled to reflect potential differences in the costs internationally. 

Actual costs for abatement options for specific countries may vary and subsequently affect these 

estimates. Additional research is required to determine actual variability in costs across regions. 

IV.3.6 References 

3M Performance Materials. October 27, 2003. Written correspondence between industry technical expert 

John G. Owens, P.E., of 3M Performance Materials and Mollie Averyt and Marian Martin Van Pelt of 

ICF Consulting. 

3M Performance Materials. September 2004. Personal communication and written correspondence 

between industry technical expert John G. Owens, P.E., of 3M Performance Materials and Mollie 

Averyt of ICF Consulting. 

Chaneski, W. November 1997. “Competing Ideas: Aqueous Cleaning—The Cost-Friendly Solution.” 

Modern Machine Shop. Available at <http://www.mmsonline.com/articles/1197ci.html>. 

DuPont FluoroProducts. October 2004. Personal communication and written correspondence between 

industry technical expert Abid Merchant of DuPont FluoroProducts and Mollie Averyt of ICF 

Consulting. 

Durkee, J.B. 1997. “Chlorinated Solvents NESHAP—Results to Date, Recommendations and 

Conclusions.” Presented at the International Conference on Ozone Layer Protection Technologies in 

Baltimore, MD, November 12-13. 

European Climate Change Program (ECCP). February 2001. “Annex I to the Final Report on European 

Climate Change Programme Working Group Industry Work Item Fluorinated Gases: ECCP 

Solvents.” Position paper provided by European Fluorocarbon Technical Committee (EFTC). 

Honeywell. 2003. “Genesolv® S-T: A New HFC-Trans Blend Based Solvent for Industrial Aerosol, 

Specialty Cleaning, Flushing and Deposition.” Honeywell Technical Bulletin. BJ-6108-3/03-XXXX. 

Available online at <http://www.genesolv.com/index1.html>. 

ICF Consulting. March 12, 1992. Cost of Alternatives to CFC-113 and Methyl Chloroform Solvent 

Cleaning for the Safe Alternatives Analysis. 

Intergovernmental Panel on Climate Change (IPCC). 1996. Climate Change 1995, The Science of Climate 

Change. Contribution of Working Group I to the Second Assessment Report of the Intergovernmental 

Panel on Climate Change. Cambridge University Press. 

Intergovernmental Panel on Climate Change Third Assessment Report (IPCC TAR). 2001.Climate Change 

2001, The Scientific Basis. Contribution of Working Group I to the Third Assessment Report of the 

Intergovernmental Panel on Climate Change. Cambridge University Press. 

March Consulting Group. 1998. Opportunities to Minimize Emissions of Hydrofluorocarbons (HFCs) from the 

European Union: Final Report. Manchester, England: March Consulting Group. 
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GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES IV-73

March Consulting Group. 1999. UK Emissions of HFCs, PFC, and SF6 and Potential Emission Reduction 

Options: Final Report. Manchester, England: March Consulting Group. 

Microcare Marketing Services, Vertrel®. 2002. “What is HFC-365 and What Does It Do?” Microcare 

Marketing Services. Available at <http://www.vertrelsolvents.com/faq/FAQ_Q33_WhatIs365.html>. 

Petroferm. January 2000. “Solvent Loss Control.” Petroferm Technical Bulletin. Available at 

<http://petroferm.com/PTF-053/pdf/papers/Solvent%20Loss%20Control%20paper%2002-00.pdf>. 

Salerno, C. January 2001. “The New Generation of Solvents: Developmental Challenges Inspire Creative 

Solutions.” CleanTech. Available at <http://www.cleantechcentral.com>. 

SEMI International. 2003. Strategic Marketing Associates’ World Fab Watch Database (WFW). April 

edition. 

United Nations Environment Programme (UNEP). 2003. UNEP 2002 Report of the Solvents, Coatings, and 

Adhesives Technical Options Committee (STOC): 2002 Assessment. Nairobi, Kenya: UNEP Ozone 

Secretariat. 

United Nations Environment Programme (UNEP). 1999a. 1998 Report of the Solvents, Coatings, and 

Adhesives Technical Options Committee (STOC): 1998 Assessment. Nairobi, Kenya: UNEP Ozone 

Secretariat. 

United Nations Environment Programme (UNEP). 1999b. The Implications to the Montreal Protocol of the 

Inclusion of HFCs and PFCs in the Kyoto Protocol. United States: UNEP HFC and PFC Task Force of the 

Technology and Economic Assessment Panel (TEAP) and Nairobi, Kenya: UNEP Ozone Secretariat. 
SECTION IV — INDUSTRIAL PROCESSES • SOLVENTS 

IV-74 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 
SECTION IV — INDUSTRIAL PROCESSES • FOAMS 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES IV-75

IV.4 HFC Emissions from Foams 

IV.4.1 Introduction 

arious HFCs are currently being used as blowing agents during the manufacture of foams. 

These high-GWP gases are substitutes for ODSs that were historically the primary blowing 

agents in the foams industry. Parties to the Montreal Protocol on Substances that Deplete the 

Ozone Layer are phasing out CFCs, and many are using HCFCs as interim substitutes. Developed and 

developing countries are at different phases of replacing CFCs with alternatives. Developed regions, such 

as the United States and EU-15, have banned the sale and distribution of some foam products 

manufactured with HCFCs and have begun transitioning to HFC use in foams where HCs and other 

alternatives are not already used. For example, Denmark, Austria, Finland, and Sweden phased out the 

use of HCFCs for foam blowing on January 1, 2002, while in the United States, HCFC-141b has been 

phased out but HCFC-22 is still being used. 

Developing countries have only recently begun transitioning from CFC-11 to HCFCs and other 

alternatives. The rate of conversion to HFCs may be limited by the current availability of other ODS 

substitutes and by technical barriers and cost. For example, the main blowing agent alternatives for CFC11 in rigid polyurethane (PU) insulating foams are HCs, such as pentanes, and HCFCs. Applying 

alternative (i.e., HFC) technologies may require the use of higher-density foam, which would result in 

incremental operating cost increases CO2. 

The most commonly used HFC blowing agents are HFC-134a, HFC-152a, HFC-245fa, and HFC365mfc in combination with HFC-227ea. These blowing agents can be released into the atmosphere 

during the foam manufacturing process, during on-site foam application, while foams are in use, and 

when foams are discarded. These agents have 100-year GWPs of 1,300, 140, 950, and 890 in combination 

with 2900, respectively, and have replaced historically used ODS blowing agents, including CFCs and 

HCFCs. Foams studied in this analysis include the following: 

• PU appliance foams found in various commercial and domestic refrigerators, vending machines, 

freezers, water heaters, picnic boxes, flasks, thermoware, and refrigerated containers (reefers). PU 

foam is the main insulation material used in refrigerators and freezers. PU foam must provide 

continuous and effective insulation to ensure the quality of the product stored inside; therefore, 

insulation properties must be maintained in order to preserve the performance of the appliance. 

Basic performance requirements of some appliances are universal (e.g., refrigerators and freezers 

keep food cold and water heaters keep water warm); however, some markets have specific 

requirements such as energy consumption limits. 

• PU spray foams are found in roofing insulation, wall insulation, and for insulation of various 

tank pipe and vessel applications. PU spray foam is used in both residential and commercial 

buildings as well as refrigerated transport. The main application in this category is spray roofing 

insulation. 

• PU continuous and discontinuous panel foam is used for insulation of cold storage, entrance and 

garage doors, insulated trucks, etc. 

• PU one-component foams are used for insulation around windows and doors, framing around 

pipes, cable holes, jointing insulating panels, and certain roof components. PU one-component 

foam is a preferred insulation method for portable and “easy to administer” applications. 

V 
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IV-76 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES

• Extruded polystyrene (XPS) boardstock foam is used mainly for thermal insulation purposes in 

buildings. Its primary uses include basement walls, exterior walls, cavity walls, and roofing. Its 

resistance to water absorption makes it a prime selection for “below-grade” applications. Some 

XPS boardstock foam types are used in protection of roads or airport runaways against frost 

(“geofoam applications”). 

IV.4.2 Baseline Emissions Estimates 

IV.4.2.1 Emissions Estimating Methodology 

The USEPA uses a detailed Vintaging Model of ODS-containing equipment and products to estimate 

the use and emissions of various ODSs and ODS substitutes in the United States, including HFCs and 

PFCs. Emissions baselines from non-U.S. countries were derived using country-specific ODS 

consumption estimates, as reported under the M ontreal Protocol in conjunction with Vintaging 

Model output for each ODS-consuming end-use. These data were incorporated into country-specific 

versions of the Vintaging Model to customize emissions estimates. In the absence of country-level data, 

these preliminary estimates were calculated by assuming that the transition from ODSs to HFCs and 

PFCs follows the same general substitution patterns internationally as the patterns observed in the 

United States. From this preliminary assumption, emissions estimates were then tailored to individual 

countries or regions by applying adjustment factors to U.S. substitution scenarios based on relative 

differences in economic growth, rates of ODS phaseout, and the distribution of ODS use across end-uses 

in each region or country. 

Emissions Equations 

Foams are given emissions profiles depending on the foam type (open cell or closed cell). Open-cell 

foams are assumed to be 100 percent emissive in the year of manufacture, as described in Equation (4.1) 

below. Closed-cell foams are assumed to emit a portion of their total HFC or PFC content upon 

manufacture, a portion at a constant rate over the lifetime of the foam, a portion at disposal, and a portion 

postdisposal, as described in Equations (4.2) through (4.6), below.1

Open-Cell Foam 

Ej = Qcj (4.1) 

where 

Ej = Emissions. Total emissions of a specific chemical in year j used for open-cell foam blowing, 

by weight. 

Qc = Quantity of chemical. Total amount of a specific chemical used for open-cell foam blowing in 

a given year, by weight. 

j = Year of emission. 

 

1 Emissions from foams may vary because of handling and disposal of the foam; shredding of foams may increase 

emissions, while landfilling of foams may abate some emissions (Scheutz and Kjeldsen, 2002; Scheutz and Kjeldsen, 

2003). Average annual emissions are assumed in the model, which may not fully account for the range of foam 

handling and disposal practices. 
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GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES IV-77

Closed-Cell Foam

Emissions from foams occur at many different stages, including manufacturing, lifetime, disposal, 

and postdisposal. 

Manufacturing emissions occur in the year of foam manufacture, and are calculated as presented in 

Equation (4.2). 

Emj = lm × Qcj (4.2) 

where 

Emj = Emissions from manufacturing. Total emissions of a specific chemical in year j due to 

manufacturing losses, by weight. 

lm = Loss rate. Percent of original blowing agent emitted during foam manufacture. 

Qc = Quantity of chemical. Total amount of a specific chemical used to manufacture closed-cell 

foams in a given year. 

j = Year of emission. 

Lifetime emissions occur annually from closed-cell foams throughout the lifetime of the foam, as 

calculated using Equation (4.3). 

Euj = lu × ΣQcj-i+l for i = 1 → k (4.3) 

where 

Euj = Emissions from lifetime losses. Total emissions of a specific chemical in year j due to lifetime 

losses during use, by weight. 

lu = Leak rate. Percentage of original blowing agent emitted during lifetime use. 

Qc = Quantity of chemical. Total amount of a specific chemical used to manufacture closed-cell 

foams in a given year. 

k = Lifetime. Average lifetime of foam product. 

i = Counter. Runs from 1 to lifetime (k). 

j = Year of emission. 

Disposal emissions occur in the year the foam is disposed, and are calculated as presented in Equation 

(4.4). 

Edj = ld × Qcj-k (4.4) 

where 

Edj = Emissions from disposal. Total emissions of a specific chemical in year j at disposal, by 

weight. 

ld = Loss rate. Percent of original blowing agent emitted at disposal. 

Qc = Quantity of chemical. Total amount of a specific chemical used to manufacture closed-cell 

foams in a given year. 

k = Lifetime. Average lifetime of foam product. 

j = Year of emission. 

Postdisposal emissions occur in the years after the foam is disposed, and are assumed to occur while the 

disposed foam is in a landfill. Currently, the only foam type assumed to have postdisposal emissions is 
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IV-78 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES

polyurethane appliance foam, which is expected to continue to emit for 32 years postdisposal, and is 

calculated as presented in Equation (4.5). 

Epj = lp × ΣQcj-m for m = k → k + 32 (4.5) 

where 

Epj = Emissions postdisposal. Total postdisposal emissions of a specific chemical in year j, by 

weight. 

lp = Leak rate. Percent of original blowing agent emitted post disposal. 

Qc = Quantity of chemical. Total amount of a specific chemical used in closed-cell foams in a given 

year. 

k = Lifetime. Average lifetime of foam product. 

m = Counter. Runs from lifetime (k) to (k + 32). 

j = Year of emission. 

To calculate total emissions from foams in any given year, emissions from all foam stages must be 

summed, as presented in Equation (4.6). 

Ej = Emj + Euj + Edj + Epj (4.6) 

where 

Ej = Total emissions. Total emissions of a specific chemical in year j, by weight. 

Emj = Emissions from manufacturing losses. Total emissions of a specific chemical in year j due to 

manufacturing leaks, by weight. 

Euj = Emissions from lifetime losses. Total emissions of a specific chemical in year j due to lifetime 

losses during use, by weight. 

Edj = Emissions at disposal. Total emissions of a specific chemical in year j due to disposal, by 

weight. 

Epj = Emissions postdisposal. Total postdisposal emissions of a specific chemical in year j, by 

weight. 

The emissions profile for foams estimated by the Vintaging Model is presented in Table 4-1. 

Regional Adjustments 

Foam sector emissions were estimated by developing Vintaging Model scenarios that were 

representative of country- or region-specific substitution and consumption patterns. To estimate baseline 

emissions, current and projected characterizations of international total foams markets were used to 

create country- or region-specific versions of the Vintaging Model. The market information was obtained 

from Ashford (2004), based on research conducted on global foam markets. Scenarios were developed for 

Japan, Europe (both EU-15 and non-EU-15 countries combined), other developed countries (excluding 

Canada), CEITs, and China. Other non-Annex I countries are assumed not to transition to HFCs during 

the scope of this analysis. Once the Vintaging Model scenarios had been run, the emissions were 

disaggregated to a country-specific level based on estimated 1989 CFC consumption for foams developed 

for this analysis. Emissions estimates were adjusted slightly to account for relative differences in 

countries’ economic growth compared to the United States (USDA, 2002; USEIA, 2001). 
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GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES IV-79

Table 4-1: USEPA’s Vintaging Model Emissions Profile for Foams’ End-Uses 

Foams End-Use 

Loss at 

Manufacturing 

(Percent) 

Annual 

Release Rate 

(Percent) 

Release 

Lifetime 

(Years) 

Loss at 

Disposal 

(Percent) 

Total 

Released 

(Percent) 

Flexible PU 100.0% 0.000% 1 0.00% 100.0% 

Polyisocyanurate boardstock 6.0% 1.000% 50 44.00% 100.0% 

Rigid PU integral skin 95.0% 2.500% 2 0.00% 100.0% 

PU appliance 4.0% 0.250% 20 27.30%a 36.3%b

PU commercial refrigeration 6.0% 0.250% 15 90.25% 100.0% 

PU spray 15.0% 1.500% 56 1.00% 100.0% 

One component 100.0% 0.000% 1 0.00% 100.0% 

PU slabstock and other 37.5% 0.750% 15 51.25% 100.0% 

Phenolic 23.0% 0.875% 32 49.00% 100.0% 

Polyolefin 95.0% 2.500% 2 0.00% 100.0% 

XPS foam sheet 40.0% 2.000% 25 0.00% 90.0% 

XPS boardstock 25.0% 0.750% 50 37.50% 100.0% 

Sandwich panel 5.5% 0.500% 50 69.50% 100.0% 

a Estimated as 30 percent of the blowing agent remaining in the foam at the time of disposal (Scheutz and Kjeldsen, 2002). 

b Emissions from disposed of products may continue if not otherwise abated. For HFCs, this analysis assumes 2 percent of the total blowing 

agent used will continue to be emitted every year after disposal. 

Emissions baselines for Canada were derived using country-specific ODS consumption estimates, as 

reported under the Montreal Protocol, in conjunction with U.S. Vintaging Model output for each ODSconsuming end-use sector. Preliminary estimates were calculated by assuming that the transition from 

ODSs to HFCs and other substitutes follows the same general substitution patterns as observed in the 

United States. 

Newly Manufactured Foam Emissions Versus Existing Foam Emissions 

Technology options explored in the foams chapter are only applicable to new (i.e., not existing) 

foams. Therefore, the technical applicabilities2 of the technology options in this sector include only 

emissions from relevant end-uses that are from newly manufactured foams, which are defined as foams 

manufactured in 2005 or later. 

IV.4.2.2 Baseline Emissions 

Table 4-2 provides a summary of baseline HFC emissions for the United States, other Annex I 

countries, non-Annex I countries3 and other groupings through 2020. Emissions estimates for HFCs from 

the foam sector are presented in MtCO2eq. These results are shown also in Figure 4-1. 

 

2 In this report, the term “technically applicable” refers to the emissions to which an option can theoretically be 

applied. 

3 This analysis assumes that China is the only non-Annex I country that would transition to HFCs during the scope of 

this study. 
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IV-80 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES

Table 4-2: Baseline Emissions Estimates for Foams (MtCO2eq) 

Country/Region 2000 2010 2020 

Africa 0.0 0.0 0.0 

Annex I 1.5 15.4 28.6 

Australia/New Zealand 0.0 0.1 0.2 

Brazil 0.0 0.0 0.0 

China 0.0 0.0 0.1 

Eastern Europe 0.0 0.0 0.0 

EU-15 1.1 5.9 11.4 

India 0.0 0.0 0.0 

Japan 0.0 3.3 4.8 

Mexico 0.0 0.0 0.0 

Non-OECD Annex I 0.0 0.0 0.1 

OECD 1.5 15.3 28.5 

Russian Federation 0.0 0.0 0.0 

South & SE Asia 0.0 0.0 0.0 

United States 0.3 5.7 11.3 

World Total 1.5 15.4 28.6 

EU-15 = European Union; OECD = Organisation for Economic Co-operation and Development. 

Figure 4-1: Total Baseline Emissions Estimates for Foams (MtCO2eq) 

CPA = Centrally Planned Asia; Non-EU FSU = non-European Union Former Soviet Union countries; OECD90+ = Organisation for Economic 

Co-operation and Development; S&E Asia = Southeast Asia. 
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GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES IV-81

IV.4.3 Cost of HFC Emissions Reductions from Foams 

This section presents a cost analysis of achieving HFC emissions reductions from the emissions 

baseline presented above. 

For chemical replacement options, costs were based on the incremental differences between using the 

HFC and switching to an HFC alternative. Financial information considered in this analysis includes 

capital costs, which account for equipment costs to modify existing plants and to maintain production 

capacity; blowing agent costs, which address the difference between costs and the quantity of the HFC 

and non-HFC alternative required; foam costs, which address changes in foam density, the amount of fire 

retardant used, the quantity and type of polyol, etc.; costs associated with profit and productivity; testing, 

training, or other costs associated with transitioning to non-HFC alternatives; and costs to produce a 

thicker, denser foam to account for any energy efficiency differences. 

In addition, industry has indicated that there will be additional conversion or “learning curve” costs, 

which are short-term costs incurred from yield, rate, and density penalties associated with conversion 

uncertainties, as well as technical support costs. Such costs are highly variable and are not addressed in 

the analysis. 

IV.4.3.1 Abatement Options 

Specific opportunities to reduce HFC emissions from the foams that were analyzed for this report fall 

into two basic categories: blowing agent replacement options and end-of-life handling options. 

Blowing agent replacement options include the following: 

• replacing HFC-134a, HFC-245fa, and HFC-365mfc/HFC-227ea with HCs in PU continuous and 

discontinuous panel foam; 

• replacing HFC-134a and HFC-152a with HCs in one-component foam; 

• replacing HFC-134a and carbon dioxide (CO2)-based blowing agents with liquid CO2

(LCD)/alcohol in XPS boardstock foam; 

• replacing HFC-245fa/CO2 (water) and HFC-365mfc/HFC-227ea with CO2 (water) in PU spray 

foam; 

• replacing HFC-245fa/CO2 (water) and HFC-365mfc/HFC-227ea with HCs in PU spray foam; 

• replacing HFC-134a with HCs in PU appliance; and 

• replacing HFC-245fa and HFC-365mfc/HFC-227ea with HCs in PU appliance foam. 

End-of-life handling options include the following: 

• PU appliance foam practice: automated process with foam grinding and landfilling and 

• PU appliance foam practice: manual process with incineration. 

All abatement option cost analyses assume a 25-year project lifetime. 

Replacement Options 

Each of the replacement options includes the use of non-HFC blowing agents such as HCs, waterblown CO2, and LCD. These foam technologies are described below. Section IV.4.3.2 gives specific 

analyses of the costs of applying these alternate blowing agents to particular foam types. 
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IV-82 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES

Hydrocarbons 

HCs such as propane, butane, isobutane, n-pentane, isopentane, cyclopentane, and isomers of hexane 

are alternatives to HFCs in foam blowing appliances. HCs are inexpensive and have near-zero direct 

GWPs, much lower than HFCs. However, key technical issues associated with the use of HCs exist: 

• Flammability. Factory upgrades that among other things ensure the use of nonsparking 

equipment and employee training are required when switching to HCs, to meet the necessary 

safety precautions in manufacturing, storage, handling, transport, and customer use. Examples of 

upgrades include a dedicated storage tank for the HC, premixers, adapted high-pressure 

dispensers, suitable molds plus process exhaust, HC detectors, and appropriate classification of 

electrical equipment. To reduce fire risks, some applications might also require the use of a larger 

quantity of flame retardants or the use of a more expensive fire retardant. 

• Volatile Organic Compounds (VOCs). Because HCs contribute to ground-level ozone and smog, 

they tend to be highly regulated. In many places, including some parts of the United States, HCs 

cannot be used without emissions controls. Implementation of these controls can lead to 

significant increases in the costs of conversion. 

• Performance. Some HCs yield only about 85 percent of the insulating value of HCFC-141b, HFC245fa, and HFC-365mfc/HFC-227ea. Producing a thicker foam can compensate for this energy 

efficiency difference, but will increase the cost of production and possible application costs (e.g., 

longer fasteners for thicker foam board). This option might not be viable in fixed-thickness 

applications, such as refrigerated trucks, or in applications where an R-value is prescribed by 

code, such as in PU spray roofing insulation. Other performance considerations include 

dimensional stability and solubility. Addressing these factors might require a more expensive 

and more limited polyol formulation. 

Costs of converting to HCs and addressing technical considerations can be significant, but vary 

according to factory-specific needs. HCs can also be used to enhance octane ratings, making them 

valuable for gasoline use and affecting their cost (Werkema, 2006). In spite of these issues, HCs are 

currently used in some applications and are being considered in a wide variety of additional applications 

(UNEP, 1998; Alliance, 2000; Alliance, 2001). 

Liquid Carbon Dioxide

The basic principle by which LCD blowing agents operate is the expansion of LCD to a gaseous state. 

LCD is blended with other foam components under pressure prior to initiating the chemical reaction. 

When decompressed, the CO2 expands, resulting in froth foam, which further expands with the 

additional release of CO2 from the water/isocyanate resin reaction that forms the PU foam matrix. LCD 

might require formulation changes to more readily dissolve the CO2 and to prevent deactivation of PU 

catalysts. When LCD is introduced at the head, often referred to as third stream, the metering equipment 

can be quite complicated and, to date, unreliable. Difficulties encountered in using LCD include the 

limited solubility of the chemical mixture, controlled decompression, and distribution of the unavoidable 

froth (UNEP, 1998). Foams blown with CO2 may suffer from lower thermal conductivity, lower 

dimensional stability, and higher density than HCFC-blown foams. To overcome these limitations, CO2

can be blended with HCs or HFCs (Williams et al., 1999; Honeywell, 2000; Alliance, 2001). 

Water-Blown (In Situ) CO2 (Water) 

In this process, CO2 produced from a chemical reaction between water and polymeric isocyanate is 

used as a blowing agent. During manufacture, no ODS or high-GWP gases are emitted, and there are 

limited health and safety risks during processing. However, foams produced using CO2/water are subject 
SECTION IV — INDUSTRIAL PROCESSES • FOAMS 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES IV-83

to the same performance limitations discussed for LCD-blown foams: lower thermal conductivity, lower 

dimensional stability, and higher density than HCFC- and HFC-blown foams. In some PU foam 

applications, a major concern when using water-generated or LCD systems is the increased open-cell 

content, which results in poorer waterproofing performance and poorer waterproofing quality of the final 

product. Another consideration is that the polymeric isocyanate content must be increased, which cannot 

be accommodated by some PU spray foam equipment. To overcome these limitations, CO2 can be 

blended with HCs or HFCs (Williams et al., 1999; Honeywell, 2000; Alliance, 2001). In some other 

applications (e.g., PU block), there can be problems with uncontrollable exotherms when using purely 

CO2 (water) systems. CO2/water blowing agent is used in extruded polystyrene boardstock in markets 

where thermal efficiency is not critical; however, in some applications, higher densities or lower 

conversion may offset the low costs of CO2/water. In some cases, costs associated with overcoming 

technical challenges are so high that CO2/water systems may be out of reach for many small and medium 

enterprises (IPCC, 2004). 

Although LCD and CO2 generated in situ have similar performance issues, the process limitations 

associated with each differ. Compared to LCD, fewer mechanical modifications are required when using 

in situ CO2, and the foam manufacturer or PU spray foam applicator can be more certain of the final CO2

content and overall foam properties (Alliance, 2001). 

End-of-Life PU Appliance Foam Practices 

There are several methods for disposal of PU foam, including landfilling and incineration, with or 

without ODS recovery and recycling or destruction. Two of the methods are described below, followed in 

Section IV.4.3.2 by specific analyses of the costs associated with each method. 

Landfilling

Traditionally, most decommissioned foam products have ended up in landfills. Although the 

regulations related to the location and management of landfills have improved considerably, there is still 

concern about the rate of release of blowing agent from foam in the first weeks after entering the landfill 

(UNEP, 2002b). 

Incineration

Incineration of foams in municipal solid waste incinerators (MSWIs) or waste-to-energy plants is a 

practical and highly competitive technique for destruction of PU foam. An advantage of this technique is 

that the foam can be incinerated without separating the foam matrix from the blowing agent prior to 

incineration, which lowers the cost and the risk of fugitive emissions (UNEP, 2002b). 

IV.4.3.2 Description and Costs of Abatement Options 

The following section describes all options in greater detail and presents a cost analysis for those 

options for which adequate cost data are available. The abatement options to reduce HFC emissions from 

the foam sector are presented by foam type: PU continuous and discontinuous panel foam, onecomponent foam, XPS boardstock foams, PU spray foams, and PU appliance foams. The technology 

options explored in this chapter are assumed to penetrate only the markets of new (i.e., not existing) 

foams. The remainder of this section provides a description of the economic assumptions for these 

abatement options. Throughout this discussion, we refer to Tables 4-4 and 4-5, which provide information 

on the technical applicability and the incremental maximum market penetrations assumed for each 

abatement option. These tables are discussed in greater detail in Section IV.4.3.3. A detailed description of 

the cost and emissions reduction analysis for each option can be found in Appendix H for this chapter. 
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IV-84 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES

PU Continuous and Discontinuous Panel Foam 

The only abatement option that was considered for this category is replacing HFCs with HCs. This 

cost analysis estimates the breakeven carbon price for a hypothetical contractor to replace HFCs with 

HCs. In the base case scenario, the blowing agent constitutes 8.7 percent of the foam, by weight. In the 

base case, 1,048,600 pounds of blowing agent are consumed (UNEP, 2002a); hence, 12,052,874 pounds of 

foam are produced (1,048,600/8.7% = 12,052,874). The foams manufactured with the alternative are 

assumed to compensate for lower insulating performance relative to HFC-blown foams by increasing the 

thickness and density of the foam. Although this end-use uses HFC-134a, HFC-245fa, and HFC365mfc/HFC-227ea, the analysis performed was based on a PU continuous and discontinuous panel foam 

contractor that uses HFC-134a. A contractor that uses HFC-245fa and HFC-365mfc/HFC-227ea would see 

higher cost savings for this replacement option because these HFCs are more expensive than HFC-134a. 

But, because HFC-245fa and HFC-365mfc/HFC-227ea have lower GWPs, the option would yield a lower 

ton of carbon equivalent (tCO2eq) savings. This analysis is based on a hypothetical PU continuous and 

discontinuous panel foam contractor that uses approximately 1 million pounds of HFC-134a per year 

(ICF Consulting, 2004). 

Cost factors that are addressed include the following: 

• capital equipment costs such as costs of installing safety equipment including nonsparking 

equipment, 

• increased cost of foam components (e.g., polyols, additives), 

• increased consumption of foam components to compensate for increased foam density, 

• worker safety, 

• increased use of fire retardant, and 

• incremental differences in the costs of blowing agents and the quantity required. 

This option is technically applicable4 to all emissions from the newly produced continuous and 

discontinuous panel foams. The technical applicability of this option from 2005 to 2020 is presented in 

Table 4-4. This analysis assumes that the incremental maximum market penetration of this option in the 

newly produced continuous and discontinuous panel market that uses HFC-134a will be 70 percent for 

the United States and 90 percent for the rest of the world by 2010, both rising to 100 percent by 2020 (see 

Table 4-5). Because the HFC is replaced by a HC, the reduction efficiency is assumed to be 100 percent. 

Assumptions specific to this substitution are presented in Appendix H for this chapter. 

One-Component Foam 

Two blowing agent replacement abatement options were considered for this end-use: 

• replacing HFC-134a with propane/butane and 

• replacing HFC-152a with propane/butane.

An analysis was performed based on a hypothetical one-component foam contractor that uses 288,000 

pounds per year of HFC-134a or HFC-152a (ICF Consulting, 2004). In the base case, the blowing agent 

constitutes 8.7 percent of the foam, by weight; hence, 3,310,345 pounds of foam is produced (288,000/8.7% 

 

4 In this report, the term “technically applicable” refers to the emissions to which an option can theoretically be 

applied. Because this option examines the replacement of HFC-134a with HCs in specific end-uses and cannot be 

retroactively applied to HFC-134a foam that has already entered the market, the technical applicability is the 

percentage of baseline foam emissions that are HFC-134a from continuous and discontinuous panels placed on the 

market after 2004. Other factors will affect the market penetration of the option assumed in this analysis. 
SECTION IV — INDUSTRIAL PROCESSES • FOAMS 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES IV-85

= 3,310,345). This cost analysis estimates the breakeven carbon price for this hypothetical contractor to 

replace HFC-134a or HFC-152a with HCs (for details, see Appendix H). 

Costs addressed include the following: 

• capital equipment costs, 

• increased cost of foam components (e.g., polyols, additives), 

• increased consumption of foam components to compensate for increased foam density, 

• worker safety, 

• increased use of fire retardant, and 

• incremental differences in the costs of blowing agents and the quantity required. 

Replacing HFC-134a with HCs for One-Component Foam

This option is technically applicable to all HFC-134a emissions from the newly produced onecomponent foams. The technical applicability of this option from 2005 to 2020 is presented in Table 4-4. 

This analysis assumes that the incremental maximum market penetration for this option in the newly 

produced one-component market that uses HFC-134a would be 70 percent for the United States and 90 

percent for the rest of the world in 2010, both increasing to 100 percent by 2020 (see Table 4-5); reduction 

efficiency is assumed to be 100 percent. Assumptions specific to this substitution are presented in 

Table H-4 in Appendix H. 

One-Component: Replacing HFC-152a with HCs

This option is technically applicable to all HFC-152a emissions from the newly produced onecomponent foams. The technical applicability of this option from 2005 to 2020 is presented in Table 4-4. 

This analysis assumes that the incremental maximum market penetration for this option in the newly 

produced one-component foam market that uses HFC-152a would be 70 percent for the United States and 

90 percent for the rest of the world by 2010, both increasing to 100 percent by 2020 (see Table 4-5); 

reduction efficiency is assumed to be 100 percent. 

XPS Boardstock Foams 

One blowing agent replacement option was considered for this end-use: 

Replacing HFC-134a and CO2-based Blends with CO2 (LCD)/Alcohol for XPS Boardstock Foams

An analysis was performed based on a hypothetical producer that manufactures approximately 1 

billion board feet (bd-ft) of foam per year, across 10 lines, using HFC-134a and CO2-based blends as the 

blowing agent. Various base case inputs and assumptions are presented in Table H-6 in Appendix H. 

This cost analysis estimates the breakeven carbon price for this hypothetical producer to replace an HFC134a and CO2-based blend with CO2/alcohol in one of the 10 lines. Using this alternative, the foam 

manufactured is assumed to compensate for lower insulating performance relative to HFC-blown foams 

by increasing the thickness of the foam in the application, where possible. Thus, incremental differences 

in indirect emissions and costs associated with energy penalties are negligible. 

Cost factors that are considered include the following: 

• blowing agent costs, 

• capital equipment costs, 

• increased consumption of foam components to compensate for increased foam density, 

• incremental differences in the costs of blowing agents and the quantity required, and 

• costs of lost capacity. 
SECTION IV — INDUSTRIAL PROCESSES • FOAMS 

IV-86 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES

The baseline blowing agent for XPS boardstock is assumed to be an HFC-134a and CO2-based blend. 

Although many XPS boardstock facilities currently use HCFCs, it is assumed that this use will be phased 

out under the Montreal Protocol and, hence, baseline alternative emissions are calculated assuming the 

phase-in of HFC-134a. This option is technically applicable5 to all emissions from newly produced XPS 

boardstock foam; that is, one could theoretically use CO2 (LCD)/alcohol in any new XPS boardstock foam 

produced. The technical applicability of this option (i.e., the percent of foam sector emissions calculated 

as arising from new XPS boardstock foam) from 2005 to 2020, is presented in Table 4-4. The incremental 

maximum market penetration of this option into the newly produced XPS foam market is assumed to be 

0 percent for the United States through 2020; 70 percent in 2010, rising to 90 percent by 2020 in all other 

developed countries and CEITs; and 70 percent in 2010, rising to 90 percent by 2020 for China (see 

Table 4-5). The option completely eliminates emissions of HFC-134a, where applied, and, hence, has a 

reduction efficiency of 100 percent. Assumptions specific to this substitution are explained below and are 

presented in Appendix H for this chapter. 

PU Spray Foams 

Two blowing agent replacement options were considered for this end-use: 

• replacing HFC-245fa/CO2 (water) and HFC-365mfc/HFC-227ea with CO2 (water) and 

• replacing HFC-245fa/CO2 (water) and HFC-365mfc/HFC-227ea with cyclopentane/ isopentane.

An analysis was performed based on a hypothetical PU spray foam contractor that produces 

approximately 127,000 pounds of foam per year using a 75/25 blend of HFC-245fa6

 and CO2 (water) as a 

blowing agent. The base case blowing agent constitutes approximately 10 percent of the foam, by weight. 

Various base case inputs and assumptions are presented in Table H-8 in Appendix H. The foams 

manufactured with the two alternatives are assumed to require an increase in thickness and density to 

compensate for lower insulating performance relative to HFC-blown foams. Thus, there are no 

incremental differences in indirect emissions and costs associated with energy penalties. Although both 

HFC-245fa and HFC-365mfc/HFC-227ea are used in this end-use, this analysis was based on a PU spray 

foam contractor that uses HFC-245fa. Cost factors that are addressed include the following: 

• fire testing costs incurred by system houses for various formulations, 

• sparking of roof top equipment units, 

• capital equipment costs, 

• employee training costs (HCs only), 

• increased cost of foam components (e.g., polyols, additives), 

• increased consumption of foam components to compensate for increased foam density, 

• increased use of fire retardant, and 

• incremental differences in the costs of blowing agents and the quantity required. 

 

5 In this report, the term “technically applicable” refers to the emissions to which an option can theoretically be 

applied. Because this option examines the replacement of HFC-134a with CO2 in only XPS foam and cannot be 

retroactively applied to foam that has already entered the market, the technical applicability is the percentage of 

baseline foam emissions that arises from HFC emissions from XPS foam placed on the market after 2004. Hence, 

technical applicability, in this sense, refers to the percentage of foam sector emissions calculated as arising from post2004 XPS foam. Other factors will affect the market penetration of the option assumed in this analysis. 

6 The EU-15 countries use a blend of HFC-365mfc and HFC-227ea in ratios of 93:7 or 87:13, while Japan uses a blend 

of HFC-245fa and HFC-365mfc in ratios of 80:20 or 70:30. This report presents a cost analysis based on the 75/25 HFC245fa/CO2 blend and applies it globally as a representative estimate. 
SECTION IV — INDUSTRIAL PROCESSES • FOAMS 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES IV-87

Annual emissions reductions were determined based on the estimated amount of blowing agent 

consumed by the hypothetical contractor and from the emissions profile used in the Vintaging Model (see 

Table 4-1). 

PU Spray: Replacing HFC-245fa/CO2 (Water) and HFC-365mfc/HFC-227ea with CO2

(Water)

This option is technically applicable7 to all emissions from the newly manufactured spray 

polyurethane foam market, but the assumed market penetration is tempered by the existence of another 

feasible option (i.e., HCs). The technical applicability of this option as well as other options from 2005 to 

2020 is presented in Table 4-4. This analysis assumes that the incremental maximum market penetration 

for this option into the newly formulated polyurethane spray foam market is 5 percent for the United 

States in 2010, and 8 percent for the rest of the world, both rising to 20 percent by 2020 (see Table 4-5); the 

reduction efficiency is assumed to be 100 percent because the HFC blowing agent is completely replaced 

(the GWP of CO2 is not included in the analysis). For cost estimating purposes, this option assumes that 

the baseline blowing agent is a 75/25 blend of HFC-245fa and CO2. 

PU Spray: Replacing HFC-245fa/CO2 (Water) and HFC-365mfc/HFC-227ea with HCs

The difference in costs between this abatement option and replacing HFC-245fa/CO2 with CO2 is the 

cost of training workers in handling, storing, and using HCs. For cost-estimating purposes, the baseline 

blowing agent is assumed to be a 75/25 blend of HFC-245fa and CO2, while the alternative blowing agent 

is assumed to be an 80/20 blend of cyclopentane and isopentane. The technical applicability of this option 

from 2005 to 2020 is presented in Table 4-4. This analysis assumes that the incremental maximum market 

penetration of this option in the newly produced PU spray foam market would be 10 percent for the 

United States and 5 percent for the rest of the world in 2010, rising in later years to 30 percent in the 

United States and 15 percent in the rest of the world (see Table 4-5); reduction efficiency is assumed to be 

100 percent. There could be some safety and liability concerns associated with this substitution, which 

could lead to reduced market penetration or increased cost of this option. 

PU Appliance Foams: Replacement Options 

Two blowing agent replacement abatement options were considered for this end-use: 

• replacing HFC-134a with cyclopentane/isopentane and 

• replacing HFC-245fa and HFC-365mfc/HFC-227ea and with cyclopentane/isopentane.

This scenario examines a hypothetical facility that manufactures approximately 536,000 refrigerators 

and consumes about 1.68 million pounds (0.00076 Mt) of blowing agent annually. The blowing agent was 

assumed to constitute approximately 12 percent of the foam. The costs of producing a refrigerator using 

each blowing agent (e.g., HFC-134a, HFC-245fa, and cyclopentane/isopentane) were provided by the 

refrigeration industry. Data have been aggregated to protect confidential business information. This 

scenario was developed for a facility manufacturing large appliances typically used in the United States. 

While other markets may use different-sized refrigerators, and hence per-appliance factors may differ, 

this analysis assumes that the resulting cost per HFC emissions abated (dollars per tCO2eq) is 

approximately the same. Factors considered in these data include the following: 

 

7

 In this report, the term “technically applicable” refers to the emissions to which an option can theoretically be 

applied. Because this option examines the replacement of HFCs with CO2 in a specific end-use and cannot be 

retroactively applied to foam that has already entered the market, the technical applicability is the percentage of 

baseline foam emissions from PU spray foam placed on the market after 2004. Other factors will affect the market 

penetration of the option assumed in this analysis. 
SECTION IV — INDUSTRIAL PROCESSES • FOAMS 

IV-88 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES

• capital costs to convert; 

• blowing agent costs; 

• foam costs, including density considerations; 

• high-impact polystyrene (HIPS) and acrylonitrile-butadiene-styrene (ABS) liner costs; 

• additional costs required to meet the U.S. 2001 National Appliance Energy Conservation Act 

(NAECA) energy efficiency standards; and 

• the energy gap between different blowing agents and energy consumption increase as a result of 

the conversion. 

HFC emissions reductions over time were derived from the emissions profile used in the Vintaging 

Model (see Table 4-1). These emissions account for gases released from the manufacturing process, 

annual release, disposal, and post disposal. Because the cost data are based on the assumption that the 

refrigerators manufactured using various blowing agents meet the same energy-efficiency standards, 

there are no incremental differences in indirect emissions and costs resulting from energy-efficiency 

differences. 

PU Appliance: Replacing HFC-134a with HCs

This option is technically applicable8 to all HFC-134a emissions from newly manufactured PU 

appliance foam. The technical applicability of this option from 2005 to 2020 is presented in Table 4-4. This 

analysis assumes that the incremental maximum market penetration in 2010 for this option in the newly 

manufactured appliance market that uses HFC-134a would be 25 percent for the United States and 85 

percent for the rest of Annex I, rising to 70 percent and 90 percent, respectively, by 2020 (see Table 4-5). 

Because the HFC is completely replaced, the reduction efficiency is 100 percent. 

PU Appliance: Replacing HFC-245fa and HFC-365mfc/HFC-227ea with HCs

Although some manufacturers may use HFC-365mfc/HFC-227ea instead of HFC-245fa, this analysis 

was performed based on the cost to replace HFC-245fa in PU appliance foams. This option is technically 

applicable to all emissions from the newly produced PU appliance foams that use HFC-245fa and HFC365mfc/HFC-227ea. The technical applicability of this option from 2005 to 2020 is presented in Table 4-4. 

This analysis assumes that the incremental maximum market penetration of this option into the newly 

manufactured appliance market that uses HFC-245fa and HFC-365mfc/HFC-227ea is 15 percent for the 

United States in 2010 rising to 50 percent by 2020. For all other countries, the market penetration in 2010 

is 85 percent, rising to 90 percent by 2020 (see Table 4-5). Because the HFC is completely replaced, the 

reduction efficiency is 100 percent. 

PU Appliance: End-of-Life Options 

In addition to the two blowing agent replacement options considered above, two end-of-life 

abatement options were considered for this end-use: 

• automated process with foam grinding, HFC adsorption, and foam landfilling in PU appliance 

foam and 

• manual process with foam incineration in PU appliance foam. 

 

8 In this report, the term “technically applicable” refers to the emissions to which an option can theoretically be 

applied. Because this option examines the replacement of HFC-134a with HCs in a specific end-use and cannot be 

retroactively applied to foam that has already entered the market, the technical applicability is the percentage of 

baseline foam emissions from appliance foam made with HFC-134a and placed on the market after 2004. Other 

factors will affect the market penetration of the option assumed in this analysis. 
SECTION IV — INDUSTRIAL PROCESSES • FOAMS 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES IV-89

The baseline emissions are based on the assumption that the remainder of the blowing agent 

contained in the appliance foam is released after the foam’s end of life, as shown in Table 4-1. Different 

technologies exist for abating end-of-life emissions in PU appliance foams. These technologies include 

landfilling the foam after recovering the blowing agent (which could either be destroyed or reclaimed 

and sold back to the market) and incinerating the foam (and the remaining blowing agent) in a Municipal 

Solid Waste Incinerator (MSWI) or waste-to-energy plant. This analysis analyzes the landfilling after 

recovering HFC and the MSWI options. This analysis assumes that when the HFC is recovered, it will still 

have value and hence contribute revenue to the process. HFC-134a and HFC-245fa are used in PU 

appliance foam in some locations. To account for the chemicals’ different GWPs and costs, this analysis 

assumes that half of the appliances processed use HFC-134a and the other half use HFC-245fa. Further 

market research could refine this assumption. 

Appendix H for this chapter presents cost estimates for each step involved in the removal or 

destruction of HFC contained in the foam, either through MSWI or grinding/adsorption/landfilling. Costs 

are presented in terms of dollars per refrigerator and in dollars per pound of HFC abated. This analysis 

uses the best cost information available; however, the costs presented should be considered illustrative 

rather than definitive. The analysis is done using the U.S. market as an example, recognizing that a U.S. 

refrigerator/freezer is typically larger than those used in other parts of the world. The final results (i.e., 

cost per unit of emissions abated) are applied to other regions because it is felt that the relative costs and 

emissions abated should scale roughly linearly to smaller appliances used elsewhere. All assumptions are 

based on a side-by-side refrigerator model. 

The following two basic methods of handling appliances to abate blowing agent emissions are 

examined: 

• Automated Process with Foam Grinding, HFC Adsorption, and Foam Landfilling. This method 

involves purchasing a sophisticated system where the appliance is brought into the system 

without much preparation. The system shreds the appliance and uses various techniques such as 

magnets and eddy current to separate the metals, plastics, and foams. The blowing agent (and the 

refrigerant) is collected by adsorption9 onto a carbon substrate. Typically, the adsorbed gases are 

then incinerated, or they can be reclaimed and sold back into the market. These systems are 

capital-intensive, costing $3,646,308 (JACO, 2004); however, once established, the manual labor is 

reduced. This type of process is generally only cost effective if a high flow of appliances (i.e., 

hundreds of thousands per year) is achieved. 

• Manual Process with Foam Incineration. This method uses mostly manual labor to evacuate and 

recycle the refrigerant, drain and recycle the compressor oil, and disassemble the appliances, 

recovering and recycling glass shelves, plastic interior parts, steel, aluminum and other valuable 

metals. The foam is removed in large pieces, which can be quickly sealed in plastic bags to 

prevent further off-gassing of the blowing agent, and sent for incineration. 

Cost factors that are addressed include the following: 

• collection and consolidation of appliances, 

• transportation of appliances to processing/disassembly location, 

• disassembly and processing of appliances, 

 

9 Other methods of blowing agent recovery are possible. For instance, some plants use liquid nitrogen to mitigate 

explosion potential with HC units. The nitrogen also serves to liquefy and collect the blowing agent. 
SECTION IV — INDUSTRIAL PROCESSES • FOAMS 

IV-90 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES

• transportation of foam to landfilling or incineration location, and 

• landfilling or incineration of foam. 

Assumptions common to both the automated process with landfilling and the manual process with 

incineration abatement options are presented in Appendix H for this chapter. 

PU Appliance: Automated Process with Foam Grinding, HFC Adsorption, and Foam 

Landfilling

The technical applicability of this option from 2005 through 2020 is presented in Table 4-4. This 

analysis assumes that the incremental maximum market penetration of this option in the appliance foam 

market in 2020 would be 10 percent in the United States, 95 percent in Europe and Japan, and 70 percent 

in the rest of the developed world (see Table 4-5). 

PU Appliance: Manual Process with Foam Incineration

The technical applicability of this option from 2005 through 2020 is presented in Table 4-4. This 

analysis assumes that the incremental maximum market penetration of this option in the appliance foam 

market in 2020 would be 30 percent in the United States and 10 percent in other developed countries 

except for the EU-15 and Japan, where the option is assumed not to penetrate the market. 

IV.4.3.3 Summary of Technical Applicability, Market Penetration, and Costs of 

Abatement Options 

Table 4-3 presents a summary of the assumed reduction efficiency, while Table 4-4 shows the 

technical applicability of the abatement options. Technical applicability values are based on the 

percentage of total foam emissions from each end-use and are derived from the baseline emissions 

methodology described in Section IV.4.2.1. The blowing agent replacement options explored in this 

chapter are assumed to penetrate only new (not existing) equipment, where “new” equipment is defined 

as equipment manufactured in 2005 or later. 

Table 4-3: Reduction Efficiency of Foam Options (Percent) 

Option Reduction Efficiency 

PU appliance: HFC-134a to HC 100.0 

PU appliance: HFC-245fa and HFC 365mfc/HFC-227ea to HC 100.0 

PU appliance: automated process with foam grinding and landfilling 90.0 

PU appliance: manual process with incineration 90.6 

PU spray: HFC-245fa/CO2 (water) and HFC-365mfc/HFC-227ea to HC 100.0 

PU spray: HFC-245fa/CO2 (water) and HFC-365mfc/HFC-227ea to CO2 (water) 100.0 

XPS boardstock: HFC-134a/CO2 to CO2/alcohol 100.0 

One-component: HFC-134a to HC 100.0 

One-component: HFC-152a to HC 100.0 

PU continuous and discontinuous panel foam: HFC-134a to HC 100.0 
SECTION IV — INDUSTRIAL PROCESSES • FOAMS 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES IV-91

 	 
 
    
  
 
  







  
  
 
 
 
 
 
 
  
 
 








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IV.4.4.1 Data Tables and Graphs 

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SECTION IV — INDUSTRIAL PROCESSES • FOAMS 

IV-92 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES Table 4-4: Technical Applicability of Foam Options (Percent) United States Europe Japan All Other Developed Countries CEITs Non-Annex I Countries (China) Option 

2005 

2010 

2015 

2020 

2005 

2010 

2015 

2020 

2005 

2010 

2015 

2020 

2005 

2010 

2015 

2020 

2005 

2010 

2015 

2020 

2005 

2010 

2015 

2020 

PU appliance: HFC-134a to 

HC 

3 2 2 4 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 

PU appliance: HFC-245fa 

and HFC-365mfc/HFC227ea to HC 

25 13 12 11 9 11 10 9 2 4 4 4 20 23 23 20 0 0 0 0 0 0 0 0 

PU appliance: automated 

process with foam grinding, HFC adsorption, and foam landfilling 

28 15 15 15 9 11 10 9 2 4 4 4 20 23 23 20 0 0 0 0 0 0 0 0 

PU appliance: manual 

process with foam incineration 

28 15 15 15 9 11 10 9 2 4 4 4 20 23 23 20 0 0 0 0 0 0 0 0 

PU spray: HFC-245fa and 

HFC-365mfc/HFC-227ea to HC 

52 34 38 40 18 25 29 28 19 28 33 36 17 31 36 36 0 0 0 0 0 0 0 0 

PU spray: HFC-245fa, or 

HFC-365mfc/HFC-227ea to CO2

52 34 38 40 18 25 29 28 19 28 33 36 17 31 36 36 0 0 0 0 0 0 0 0 

XPS boardstock: HFC-134a 

to CO2/alcohol 

0 41 38 33 26 22 19 15 37 33 31 29 0 0 0 0 0 4 8 8 0 0 0 0 

One-component: HFC-134a 

to HC 

0 1 1 1 11 3 3 2 1 1 1 1 0 0 0 0 100 96 92 92 100 100 100 100 

One-component: HFC-152a 

to HC 

0 0 0 0 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 

PU continuous and 

discontinuous panel: HFC-134a to HC 

1 1 1 1 8 9 10 9 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 

Note: Assumed technical applicability of options is presented as a percentage of total foam sector baseline emissions. 
SECTION IV — INDUSTRIAL PROCESSES • FOAMS 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES IV-93 Table 4-5: Incremental Maximum Market Penetration Expressed as a Percentage of New Emissions for Which the Options Apply United States Europe Japan All Other Developed Countries CEITs Non-Annex I Countries (China) Option 

2005 

2010 

2015 

2020 

2005 

2010 

2015 

2020 

2005 

2010 

2015 

2020 

2005 

2010 

2015 

2020 

2005 

2010 

2015 

2020 

2005 

2010 

2015 

2020 

PU appliance: HFC-134a to 

HC 

0 25 50 70 65 85 90 90 65 85 90 90 65 85 90 90 65 85 90 90 65 85 90 90 

PU appliance: HFC-245fa 

and HFC-365mfc/HFC227ea to HC 

0 15 30 50 65 85 90 90 65 85 90 90 65 85 90 90 65 85 90 90 65 85 90 90 

PU appliance: automated 

process with foam grinding, HFC adsorption, and foam landfilling 

0 0 5 10 0 0 0 95 0 0 0 95 0 0 0 70 0 0 0 0 0 0 0 0 

PU appliance: manual 

process with foam incineration 

0 0 20 30 0 0 0 0 0 0 0 0 0 0 0 10 0 0 0 0 0 0 0 0 

PU spray: HFC-245fa and 

HFC-365mfc/HFC-227ea to HC 

5 10 20 30 0 5 10 15 0 5 10 15 0 5 10 15 0 5 10 15 0 5 10 15 

PU spray: HFC-245fa, or 

HFC-365mfc/HFC-227ea to CO2

0 5 10 20 5 8 15 20 5 8 15 20 5 8 15 20 5 8 15 20 5 8 15 20 

XPS boardstock: HFC-134a 

to CO2/alcohol 

0 0 0 0 50 70 70 90 50 70 70 90 50 70 70 90 50 70 70 90 50 70 70 90 

One-component: HFC-134a 

to HC 

50 70 90 100 60 90 95 100 60 90 95 100 60 90 95 100 60 90 95 100 60 90 95 100 

One-component: HFC-152a 

to HC 

50 70 90 100 60 90 95 100 60 90 95 100 60 90 95 100 60 90 95 100 60 90 95 100 

PU continuous and 

discontinuous panel: HFC-134a to HC 

50 70 90 100 60 90 95 100 60 90 95 100 60 90 95 100 60 90 95 100 60 90 95 100 
SECTION IV — INDUSTRIAL PROCESSES • FOAMS 

IV-94 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES Table 4-6: Incremental Maximum Market Penetration Expressed as a Percentage of All Emissions United States Europe Japan All Other Developed Countries CEITs Non-Annex I Countries (China) Option 

2005 

2010 

2015 

2020 

2005 

2010 

2015 

2020 

2005 

2010 

2015 

2020 

2005 

2010 

2015 

2020 

2005 

2010 

2015 

2020 

2005 

2010 

2015 

2020 

PU appliance HFC-134a to 

HC 

0 20 39 37 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 

PU appliance HFC-245fa 

and HFC-365mfc/HFC227ea, to HC 

0 11 22 36 55 73 80 82 61 81 85 87 61 81 86 87 0 0 0 0 0 0 0 0 

PU appliance automated 

process with foam grinding, HFC adsorption, and foam landfilling 

0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 

PU appliance manual 

process with foam incineration 

0 0 0 3 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 

PU spray HFC-245fa and 

HFC-365mfc/HFC-227ea, to HC 

4 8 15 23 0 4 7 11 0 3 6 10 0 4 8 11 0 0 0 0 0 0 0 0 

PU spray HFC-245fa, or 

HFC-365mfc/HFC-227ea to CO2

0 4 7 14 4 6 11 15 3 5 10 14 5 7 12 16 0 0 0 0 0 0 0 0 

XPS boardstock: HFC134a/CO2 to CO2/alcohol 0 0 0 0 45 61 63 78 49 67 68 83 0 0 0 0 0 70 70 86 0 0 0 0 One-component: HFC-134a 

to HC 

0 70 90 100 60 90 95 100 60 90 95 100 0 0 0 0 60 90 95 100 60 90 95 100 

One-component: HFC-152a 

to HC 

0 70 90 100 60 90 95 100 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 

PU continuous and 

discontinuous panel: HFC-134a to HC 

40 60 77 87 35 61 73 82 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 
SECTION IV — INDUSTRIAL PROCESSES • FOAMS 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES IV-95 Table 4-7: Emissions Reductions Off Total Foams Baseline (Percent) United States Europe Japan All Other Developed Countries CEITs Non-Annex I Countries (China) 

2005 

2010 

2015 

2020 

2005 

2010 

2015 

2020 

2005 

2010 

2015 

2020 

2005 

2010 

2015 

2020 

2005 

2010 

2015 

2020 

2005 

2010 

2015 

2020 

PU appliance HFC-134a 

to HC 

0.0 0.5 0.9 1.5 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 

PU appliance HFC-245fa 

and HFC-365mfc/ HFC-227ea to HC 

0.0 1.4 2.7 3.9 5.2 7.8 8.3 7.3 1.1 3.1 3.4 3.5 12.0 19.0 19.8 17.5 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 

PU appliance automated 

process with foam grinding, HFC adsorption, and foam landfilling 

0.0 0.0 0.0 0.1 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 

PU appliance manual 

process with foam incineration 

0.0 0.0 0.0 0.4 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 

PU spray HFC-245fa and 

HFC-365mfc/ HFC227ea to HC 

2.3 2.8 5.9 9.1 0.0 0.9 2.1 3.1 0.0 0.8 2.0 3.5 0.0 1.2 2.8 4.2 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 

PU spray HFC-245fa and 

HFC-365mfc/ HFC227ea to HC 

0.0 1.3 2.8 5.6 0.7 1.6 3.2 4.3 0.5 1.5 3.2 5.0 0.8 2.1 4.4 5.9 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 

XPS boardstock: HFC134a/CO2 to 

CO2/alcohol 

0.0 0.0 0.0 0.0 11.7 13.4 11.8 11.7 18.1 21.8 21.0 24.1 0.0 0.0 0.0 0.0 0.0 2.7 5.4 6.9 0.0 0.0 0.0 0.0 

One-component: HFC134a to HC 0.0 0.6 0.6 0.6 6.4 3.1 2.9 2.4 0.8 0.9 0.9 0.9 0.0 0.0 0.0 0.0 60.0 86.5 87.6 92.0 60.0 90.0 95.0 100.0 One-component: HFC152a to HC 0.0 0.0 0.0 0.0 0.5 0.7 0.6 0.5 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 PU continuous and 

discontinuous panel: HFC-134a to HC 

0.3 0.3 0.5 0.6 2.7 5.7 7.2 7.5 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 

Total 2.6 7.0 13.5 21.8 27.2 33.1 36.1 36.7 20.5 28.2 30.5 36.9 12.7 22.4 27.0 27.5 60.0 89.2 93.0 98.9 60.0 90.0 95.0 100.0 
SECTION IV — INDUSTRIAL PROCESSES • FOAMS 

IV-96 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES

Table 4-8: Summary of Abatement Option Cost Assumptions 

Option 

Time 

Horizon 

(years): Unit of Costs 

Base OneTime Cost 

Base 

Annual 

Cost 

Base 

Annual 

Savings 

Net Annual 

Cost 

Continuous and 

discontinuous panel: 

HFC-134a to HC 

25 Per contractora $273,473 $2,175,424 $2,164,154 $11,270 

One-component: HFC134a to HC 25 Per contractorb $341,841 $292,711 $639,673 –$346,962 

One-component: HFC152a to HC 25 Per contractorb $341,841 $292,711 $342,779 –$50,068 

XPS: HFC-134a/CO2 to 

CO2/Alcohol 

25 Per 

manufacturerc

$5,013,674 $774,711 $3,582,474 –$2,807,764 

PU spray: HFC245fa/CO2 to CO225 Per contractord $4,000 $54,264 $9,724 $44,541 

PU spray: HFC245fa/CO2 to HC 25 Per contractord $13,728e $39,560 $47,060 –$7,500 

PU appliance: HFC-134a 

to HC 

25 Per factoryf $50,000,000 $0 $1,506,160 –$1,506,160 

PU appliance: HFC-245fa 

to HC 

25 Per factoryf $50,000,000 $11,202,400h $0h $11,202,400 

PU appliance: automated 

process with foam 

grinding, HFC 

adsorption, and foam 

landfilling 

25 Per facilityg $3,646,308 $1,848,159 $481,809 $1,366,350 

PU appliance: manual 

process with foam 

incineration 

25 Per facilityi $182,315 $456,528 $48,239 $408,289 

a Based on a hypothetical PU continuous and discontinuous panel foam contractor that produces approximately 12 million pounds of foam per 

year. 

b Based on a hypothetical one component foam contractor that produces approximately 3.3 million pounds of foam per year. 

c Based on a hypothetical XPS boardstock foam manufacturer that produces about 1 billion board-feet of foam per year. 

d Based on a hypothetical PU spray foam contractor that produces about 127,000 pounds of foam per year. 

e Only U.S.-based costs are presented in this summary table. However, EU-15 and Japan costs are $21,251 and $31,536 and are applied 

accordingly. U.S. costs are applied to all other countries.

f

 Based on a hypothetical factory that manufactures 536,000 refrigerators per year. 

g Based on a facility that is assumed to process about 100,000 refrigerators per year. 

h Base annual savings are incorporated into the base annual costs. 

I

 Based on a facility that is assumed to process 10,000 refrigerators per year. 
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GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES IV-97

Table 4-9: Country/Regional Emissions Reductions in 2010 and Breakeven Costs for Foams at 10% Discount 

Rate, 40% Tax Rate ($/tCO2eq) 

2010 

Country/Region $0 $15 $30 $45 $60 >$60 

Africa 0.00 0.00 0.00 0.00 0.00 0.00 

Annex I 2.06 2.41 2.41 2.66 2.66 3.40 

Australia/New Zealand 0.00 0.00 0.00 0.00 0.00 0.02 

Brazil 0.00 0.00 0.00 0.00 0.00 0.00 

China 0.02 0.02 0.02 0.02 0.02 0.02 

Eastern Europe 0.00 0.01 0.01 0.01 0.01 0.01 

EU-15 1.06 1.40 1.40 1.49 1.49 1.95 

India 0.00 0.00 0.00 0.00 0.00 0.00 

Japan 0.77 0.77 0.77 0.82 0.82 0.92 

Mexico 0.00 0.00 0.00 0.00 0.00 0.00 

Non-OECD Annex I 0.03 0.03 0.03 0.03 0.03 0.03 

OECD 2.03 2.39 2.39 2.64 2.64 3.38 

Russian Federation 0.02 0.02 0.02 0.02 0.02 0.02 

South & SE Asia 0.00 0.00 0.00 0.00 0.00 0.00 

United States 0.19 0.21 0.21 0.31 0.31 0.39 

World Total 2.08 2.43 2.43 2.69 2.69 3.43 

EU-15 = European Union; OECD = Organisation for Economic Co-operation and Development. 

Table 4-10: Country/Regional Emissions Reductions in 2020 and Breakeven Costs for Foams at 10% 

Discount Rate, 40% Tax Rate ($/tCO2eq) 

2020 

Country/Region $0 $15 $30 $45 $60 >$60 

Africa 0.00 0.00 0.00 0.00 0.00 0.00 

Annex I 4.57 5.49 5.49 7.09 7.09 8.75 

Australia/New Zealand 0.01 0.01 0.01 0.02 0.02 0.05 

Brazil 0.00 0.00 0.00 0.00 0.00 0.00 

China 0.05 0.05 0.05 0.05 0.05 0.05 

Eastern Europe 0.01 0.01 0.01 0.01 0.01 0.01 

EU-15 2.00 2.86 2.86 3.34 3.34 4.17 

India 0.00 0.00 0.00 0.00 0.00 0.00 

Japan 1.37 1.37 1.37 1.61 1.61 1.77 

Mexico 0.00 0.00 0.00 0.00 0.00 0.00 

Non-OECD Annex I 0.05 0.05 0.05 0.05 0.05 0.05 

OECD 4.52 5.44 5.44 7.04 7.04 8.71 

Russian Federation 0.04 0.04 0.04 0.04 0.04 0.04 

South & SE Asia 0.00 0.00 0.00 0.00 0.00 0.00 

United States 1.10 1.17 1.17 1.98 1.98 2.47 

World Total 4.62 5.54 5.54 7.14 7.14 8.81 

EU-15 = European Union; OECD = Organisation for Economic Co-operation and Development. 
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IV-98 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES

Table 4-11: World Breakeven Costs and Emissions Reductions in 2020 for Foams 

Cost 

(2000$/tCO2eq)

DR=10%, 

TR=40% 

Reduction Option Low High

Emissions

Reduction

of Option 

(MtCO2eq)

Reduction

from 2020 

Baseline 

(%)

Running

Sum of 

Reductions

(MtCO2eq)

Cumulative 

Reduction

from 2020 

Baseline 

(%)

XPS boardstock: HFC-134a/CO2

(LCD)—based blends to CO2

(LCD)/alcohol

–$7.81 –$7.81 2.49 8.7% 2.49 8.7% 

PU Spray: HFC-245fa/CO2

(water) to HC 

–$5.19 –$2.91 1.59 5.5% 4.08 14.2% 

PU one-component HFC-134a to 

HC

–$1.76 –$1.76 0.48 1.7% 4.56 15.9% 

PU one-component HFC-152a to 

HC

–$0.15 –$0.15 0.06 0.2% 4.62 16.1% 

PU continuous and 

discontinuous: HFC-134a to 

HC

$0.86 $0.86 0.92 3.2% 5.54 19.3% 

PU Appliance: automated 

process with foam grinding, 

HFC adsorption, and foam 

landfilling

$36.07 $36.07 0.01 0.0% 5.55 19.4% 

PU Spray: HFC-245fa/CO2

(water) to CO2 (water) 

$41.84 $41.84 1.42 5.0% 6.98 24.4% 

PU appliance: HFC-134a to HC $42.06 $42.06 0.17 0.6% 7.14 24.9% 

PU appliance: manual process 

with foam incineration 

$82.54 $82.54 0.04 0.1% 7.18 25.1% 

PU appliance: HFC-245fa to HC $192.54 $192.54 1.62 5.7% 8.81 30.7% 

Market Penetrations 

Market penetrations of abatement technologies are based on published reports and discussions with 

industry experts in the U.S. and EU-15. However, actual market penetrations of these technologies may 

be different. For example, market penetration rates and hence emissions reduction potentials may be 

higher in countries that are establishing climate policies. 

PU Continuous and Discontinuous Panel Foam 

For PU continuous and discontinuous panel foam, the cost analysis was performed based on a 

contractor that uses HFC-134a; however, this end-use also uses HFC-245fa, and HFC-365mfc/HFC-227ea. 

XPS Boardstock Foam 

Capital and annual costs for abatement technologies of XPS boardstock foam were based on a 

consensus reached among industry representatives or averages of different estimates provided by 

different manufacturers. These averages may not reflect the full range of costs that might be experienced. 
SECTION IV — INDUSTRIAL PROCESSES • FOAMS 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES IV-99

Figure 4-2: 2010 MAC for Foams, 10% Discount Rate, 40% Tax Rate 

EU-15 = European Union; OECD = Organisation for Economic Co-operation and Development. 

Figure 4-3: 2020 MAC for Foams, 10% Discount Rate, 40% Tax Rate 

EU-15 = European Union; OECD = Organisation for Economic Co-operation and Development. 

IV.4.5 Summary 

Baseline emissions of HFCs from foams are estimated to grow from 1.5 to 28.6 MtCO2eq between 

2000 and 2020. In 2020, OECD countries are assumed to account for almost 100 percent of the emissions, 

while U.S. emissions and EU-15 emissions are each assumed to account for about 40 percent of this total. 

The largest emissions growth is expected in the United States, from 0.3 MtCO2eq in 2000 to 11.3 MtCO2eq 

in 2020. 
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IV-100 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES

This analysis considers the following eight replacement emissions mitigation options for PU spray, 

PU appliance, XPS boardstock, PU continuous and discontinuous panel foam, and one-component foams, 

as well as the following two end-of-life options for PU appliance foams: 

• replacing HFC-134a, HFC-245fa, and HFC-365mfc/HFC-227ea with HCs in PU continuous and 

discontinuous panel foam; 

• replacing HFC-134a with HCs in one-component foam; 

• replacing HFC-152a with HCs in one-component foam; 

• replacing HFC-134a/CO2 (LCD) with CO2 (LCD)/alcohol in XPS boardstock foam; 

• replacing HFC-245fa/CO2 (water) and HFC-365mfc/HFC-227ea with CO2 (water) in PU spray 

foam; 

• replacing HFC-245fa/CO2 (water) and HFC-365mfc/HFC-227ea with HCs in PU spray foam; 

• replacing HFC-134a with HCs in PU appliance foam; 

• replacing HFC-245fa and HFC 365mfc/HFC-227ea with HCs in PU appliance foam; 

• end-of-life PU appliance foam practice: automated process with foam grinding, HFC adsorption, 

and foam landfilling in PU appliance foam; and 

• end-of-life PU appliance foam practice: manual process with foam incineration in PU appliance 

foam. 

The emissions reduction benefits of each option were compared in each region. For spray end-uses, 

the costs associated with converting to alternative blowing agents differ between the United States, EU, 

and Japan. The costs per tCO2eq of all other abatement options for these three regions are equivalent 

because available data on costs for abatement technologies were not scaled to reflect potential differences 

in the costs internationally. Additional research may be required to determine actual variability in costs 

across regions. This analysis shows that there are several cost-effective options available at the 10 percent 

discount rate and 40 percent tax rate that may be used to eliminate the use of HFCs and reduce HFCassociated emissions from foams. 

IV.4.6 References 

Alliance for Responsible Atmospheric Policy. May 26, 2000. Comments of the Alliance for Responsible 

Atmospheric Policy on Draft of “Cost and Emission Reduction Analysis of HFC Emissions from 

Foams in the United States.” Fax sent from Alliance to ICF Consulting. 

Alliance for Responsible Atmospheric Policy. May 16, 2001. Review of the USEPA Draft Chapter 9 by 

Members of the Alliance for Responsible Atmospheric Policy. 

Ashford, Paul. April 8, 2004. Personal communication between ICF Consulting and Paul Ashford of Caleb 

Group. 

Honeywell. September 11, 2000. Comments of Honeywell Inc. on U.S. Environmental Protection Agency’s 

(USEPA’s) proposed listing of certain HCFCs and blends as “unacceptable” substitutes for HCFC141b—65 Fed. Reg. 42653 (11 July 2000). Personal communication from Richard Ayres of Howrey, 

Simon, Arnold, and White to Anhar Karimjee of the USEPA. Available from the USEPA’s Foams 

Docket A-200-18, Document IV-D-41. 

ICF Consulting. March 2004. Personal communication with Bob Russell, ICF Consulting. 

Intergovernmental Panel on Climate Change (IPCC). 2004. “Special Report on Ozone and Climate.” 

Second-Order-Draft. Technology and Economic Assessment Panel. 
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GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES IV-101

JACO Environmental. May 13, 2004. Personal Communication between Michael Dunham, Director, 

Energy & Environmental Programs, JACO Environmental, Inc., and Colm Kenny of U.S. 

Environmental Protection Agency (USEPA). 

Scheutz, C., and P. Kjeldsen. April 2002. “Determination of the Fraction of Blowing Agent Released from 

Refrigerator/Freezer Foam After Decommissioning the Product.” Denmark: Environment and 

Resources DTU, Technical University of Denmark. 

Scheutz, C., and P. Kjeldsen. August 2003. “Attenuation of Alternative Blowing Agents in Landfills.” 

Denmark: Environment and Resources DTU, Technical University of Denmark. 

United Nations Environment Programme (UNEP). 1998. “1998 Report of the Flexible and Rigid Foams 

Technical Options Committee.” UNEP. 

United Nations Environment Programme (UNEP). 2002a. “Report of the Technology and Economic 

Assessment Panel. Progress Report. Montreal Protocol on the Substances that Deplete the Ozone 

Layer.” UNEP. 

United Nations Environment Programme (UNEP). 2002b. “Report of the Technology and Economic 

Assessment Panel of the Montreal Protocol, Task Force on Destruction Technologies, Volume 3b, 

April.” UNEP. 

U.S. Department of Agriculture (USDA). 2002. “Real GDP (2000 dollars) Historical. International 

Macroeconomic Data Set. Available at <http://www.ers.usda.gov/data/ macroeconomics/>. 

U.S. Energy Information Administration (USEIA). 2001. “International Energy Outlook, Table 7. 

Comparison of Economic Growth Rates by Region, 1997–2020.” Washington: U.S. Department of 

Energy, Energy Information Agency. 

Werkema, T. April 2006. Comments provided by Tom Werkema to the USEPA. 

Whirlpool. April 19, 2004. Personal communication between Robert W. Johnson of Whirlpool and Colm 

Kenny of the USEPA. 

Williams, D.J., M.C. Bogdan, and P.B. Logsdon. 1999. “Optimizing Performance and Value: HFC-245fa 

and Blends of HFC-245fa for Insulating Foams.” Conference Proceedings from the Earth Technologies 

Forum TF, pp. 290-302. 
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IV-102 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES
SECTION IV — INDUSTRIAL PROCESSES • AEROSOLS 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES IV-103

IV.5 HFC Emissions from Aerosols 

IV.5.1 Introduction 

erosol propellants are used in metered dose inhalers (MDIs), as well as a variety of consumer 

products. Historically, the majority of aerosol applications have used CFCs as propellants; 

however, efforts have been made to transition away from CFC propellants. As a result of 

initiatives under the Montreal Protocol, many pharmaceutical companies that produce MDIs have 

committed to develop alternatives to CFC-based MDIs. Furthermore, many consumer products, such as 

spray deodorants and hair sprays, and specialty aerosol uses, such as freeze spray and dust removal 

products, have successfully been reformulated with HC propellants or replaced with NIK substitutes 

such as pump sprays or solid and roll-on deodorants. Such transitions occurred in the United States as far 

back as 1977, when the country placed a ban on CFC propellants in non-MDI aerosols for nonessential 

uses. 

Various HFCs have also been introduced as alternative propellants in aerosol applications. These 

HFCs include HFC-134a, HFC-152a, and HFC-227ea and are associated, respectively, with 100-year 

GWPs of 1,300, 140, and 2,900. Aerosol HFCs are emitted from pharmaceutical products (primarily 

MDIs)1 and consumer and industrial products (primarily specialty aerosols). 

The pharmaceutical aerosol industry is actively working to develop HFC-propellant MDIs, a type of 

inhaled therapy used to treat asthma and chronic obstructive pulmonary disease (COPD). The earliest 

non-CFC substitute products used HFC-134a, but eventually the industry expects products to use HFC227ea as well. In addition to MDIs that use propellants, dry powder inhalers (DPIs) can be used as a 

substitute for some MDIs. Because MDIs are medical devices, substitute propellants must meet far stricter 

performance and toxicology specifications than required for most other products. In the United States, for 

example, the Food and Drug Administration (FDA) must approve MDIs reformulated with an alternative 

propellant before they can enter the market. 

Chemical manufacturers are also marketing HFCs, especially HFC-152a and HFC-134a, as aerosol 

propellants in consumer products, primarily for use in specialty applications. This is particularly true for 

applications where flammability or volatile organic compound (VOC) emissions and their impact on 

urban air quality are of concern. If HFC use is accelerated, public concern over these emissions may 

increase. This concern will likely spur the aerosol industry to promote responsible use of these chemicals, 

for instance, by implementing emissions abatement options examined in this report (UNEP, 1999). 

IV.5.2 Baseline Emissions Estimates 

IV.5.2.1 Emissions Estimating Methodology 

Description of Methodology 

Specific information on the emissions model used to calculate ODS substitute emissions from all 

sectors calculates aerosol emissions is described below. 

The USEPA uses a detailed Vintaging Model of ODS-containing equipment and products to estimate 

the use and emissions of various ODS substitutes in the United States, including HFCs. Emissions 

 

1 This analysis excludes non-MDI aerosols produced by the pharmaceutical industry such as bandage sprays. 

A 
SECTION IV — INDUSTRIAL PROCESSES • AEROSOLS 

IV-104 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

baselines from non-U.S. countries were derived using country-specific ODS consumption estimates as 

reported under the M ontreal Protocol in conjunction with Vintaging Model output for each ODSconsuming end-use sector. For sectors where detailed information was available, these data were 

incorporated into country-specific versions of the Vintaging Model to customize emissions estimates. In 

the absence of country-level data, these preliminary estimates were calculated by assuming that the 

transition from ODSs to HFCs and other substitutes follows the same general substitution patterns 

internationally as observed in the United States. From this preliminary assumption, emissions estimates 

were then tailored to individual countries or regions by applying adjustment factors to U.S. substitution 

scenarios, based on relative differences in economic growth, rates of ODS phaseout, and the distribution 

of ODS use across end-uses in each region or country. 

Emissions Equations 

All HFCs used in aerosols are assumed to be emitted in the year of manufacture. Since there is 

currently no aerosol recycling, all of the annual production of aerosol propellants is assumed to be 

released to the atmosphere. The following equation describes the emissions from the aerosols sector: 

Ej = Qcj , (5.1) 

where 

Ej = Total emissions of a specific chemical in a year j from use in aerosol products, by weight. 

Qcj = Total quantity of a specific chemical contained in aerosol products sold in the year j, by 

weight 

j = Year of emissions 

For aerosols, two separate baseline emissions were created; one baseline tracks HFC emissions from 

the MDI industry, while the other estimates HFC emissions from consumer and specialty products (i.e., 

non-MDI aerosols). 

Regional Adjustments 

The adjustment factor assumptions used in the global aerosol emissions estimating methodology 

include both economic and timing adjustment factors. The timing factors reflect that some nations are not 

moving at the same pace away from using CFCs and toward using HFCs as other nations are. For all ODS 

end-uses, by 2005, non-Annex I (i.e., developing) countries are assumed to be 75 percent through the CFC 

transition, and by 2010, the CFC transition should be complete. These timing factors are partially offset by 

generally higher growth rates in developing countries. 

In addition, the methodology used to estimate global aerosol emissions includes an adjustment 

specific to non-MDI aerosols. This adjustment was necessary because the ban on CFC use in aerosols 

caused the United States to transition out of CFCs earlier than other countries. Therefore, the unweighted 

U.S. consumption of non-MDI aerosol ODS substitutes (including a large market segment that 

transitioned into NIK or HC substitutes) was used as a proxy for U.S. 1990 non-MDI ODS consumption. 

For countries other than the United States, it was then assumed that 15 percent of the non-MDI aerosols 

ODS consumption transitioned to HFCs, while the remainder is assumed to transition to NIK or HC 

alternatives. 
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GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES IV-105

IV.5.2.2 Baseline Emissions 

Table 5-1 and Figure 5-1 display total HFC emissions estimates in million metric tons of carbon 

dioxide equivalent (MtCO2eq) for the MDI aerosol sector, while Table 5-2 and Figure 5-2 represent the 

non-MDI aerosols sector. Both HFC-134a and HFC-227ea are expected to be emitted from using MDIs in 

the future as substitutes for CFCs. The MDI emissions baseline accounts for all emissions of HFC-227ea 

from the aerosols sector. Non-MDI emissions are responsible for the majority of the HFC-134a emissions 

from the aerosols sector (mainly for specialty applications) and all of the HFC-152a emissions (mostly 

formulated consumer products). 

IV.5.3 Cost of HFC Emissions Reductions for Aerosols 

This section presents a cost analysis for achieving HFC emissions reductions from the emissions 

baselines presented in Tables 5-1 and 5-2. The cost analysis for the MDI option assumes a 15-year project 

lifetime; all cost analyses for the non-MDI emissions reduction options assume a 10-year project lifetime. 

Each abatement option is described below. 

IV.5.3.1 Description and Cost Analysis of Abatement Options 

Four potential mitigation options are analyzed in this report. The first mitigation option has the 

potential to abate emissions from the MDI baseline (Table 5-1), while the other three options have the 

potential to abate emissions from the non-MDI baseline (Table 5-2). The options are as follows: 

• MDI replacement with DPIs (DPI [MDI]) 

• non-MDI replacement with lower GWP HFCs (HFC-134a to HFC-152a [non-MDI]) 

• non-MDI replacement with NIK alternatives (HFC to NIK [non-MDI]) 

• non-MDI replacement with HC aerosol propellants (HFC to HC [non-MDI]) 

DPIs have been authorized as a substitute for some HFC-propellant MDIs. The non-MDI baseline 

includes emissions from specialty aerosol uses such as tire inflators, electronics cleaning products, dust 

removal, freeze spray, signaling devices, and mold release agents, as well as consumer products such as 

hairsprays, mousse, deodorants and antiperspirants, household products, and spray paints (Arthur D. 

Little, 1999). HFCs are currently used when flammability issues cannot easily be overcome, such as tire 

inflators and air signaling horns that use HFC-134a to avoid potential explosivity associated with highly 

flammable propellants like propane or butane (Arthur D. Little, 1999). HFC-152a has been used in dusters 

since 1993 (UNEP, 1999), and as a replacement for HFC-134a in general aerosol applications. Converting 

to HFC-152a in these applications is a reduction strategy that has had significant success thus far and is 

expected to continue. The other options to reduce HFC emissions from non-MDI aerosol applications 

addressed in this analysis include NIK replacement and HC aerosol propellants. Other options, such as 

using carbon dioxide as a propellant, may also exist but have not been addressed in this analysis because 

specific information is lacking. 

The remainder of this section describes the economic assumptions for these four abatement options. 

A detailed description of the cost and emissions reduction analysis for each option can be found in 

Appendix I for this chapter. 
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IV-106 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

Table 5-1: Total Baseline HFC Emissions Estimates from MDI Aerosols (MtCO2eq) 

Country/Region 2000 2010 2020 

Africa 0.0 0.4 0.9 

Annex I 2.8 8.5 13.8 

Australia/New Zealand 0.2 0.3 0.4 

Brazil 0.0 0.1 0.2 

China 0.0 0.7 2.2 

Eastern Europe 0.1 0.3 0.4 

EU-15 1.9 2.8 3.8 

India 0.0 0.2 0.6 

Japan 0.1 0.9 1.6 

Mexico 0.0 0.3 0.7 

Non-OECD Annex I 0.4 1.3 1.8 

OECD 2.4 7.6 12.8 

Russian Federation 0.4 1.1 1.5 

South & SE Asia 0.0 0.3 0.8 

United States 0.1 2.7 5.5 

World Total 2.9 11.0 20.1 

EU-15 = European Union; OECD = Organisation for Economic Co-operation and Development. 

Figure 5-1: Total Baseline HFC Emissions Estimates from MDI Aerosols (MtCO2eq) 

CPA = Centrally Planned Asia; Non-EU FSU = non-European Union Former Soviet Union countries; S&E Asia = Southeast Asia; OECD90+ = 

Organisation for Economic Co-operation and Development. 
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GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES IV-107

Table 5-2: Total Baseline HFC Emissions Estimates from Non-MDI Aerosols (MtCO2eq) 

Country/Region 2000 2010 2020 

Africa 0.0 0.0 0.0 

Annex I 24.1 32.6 39.4 

Australia/New Zealand 0.7 0.9 1.1 

Brazil 0.0 0.0 0.0 

China 0.0 0.0 0.0 

Eastern Europe 1.1 2.9 4.0 

EU-15 10.5 11.8 13.3 

India 0.0 0.0 0.0 

Japan 0.0 0.0 0.0 

Mexico 0.0 0.0 0.0 

Non-OECD Annex I 2.1 5.5 7.2 

OECD 22.0 27.1 32.2 

Russian Federation 1.6 4.2 5.5 

South & SE Asia 0.0 0.0 0.0 

United States 9.9 12.1 14.8 

World Total 24.2 32.7 39.5 

EU-15 = European Union; OECD = Organisation for Economic Co-operation and Development. 

Figure 5-2: Total Baseline HFC Emissions Estimates from Non-MDI Aerosols (MtCO2eq) 

CPA = Centrally Planned Asia; Non-EU FSU = non-European Union Former Soviet Union countries; S&E Asia = Southeast Asia; OECD90+ = 

Organisation for Economic Co-operation and Development. 
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IV-108 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

MDI: Replacement with Dry Powdered Inhalers (DPIs) 

As MDIs transition away from CFC use, alternatives such as HFC propellants, DPIs, and oral 

medications are being developed. Although HCs have replaced CFCs as propellants in many commercial 

aerosols, they have been found to be unacceptable for use in MDIs (International Pharmaceutical Aerosol 

Consortium [IPAC], 1999). Given the unique medical requirements for developing MDIs, and the fact that 

the industry has been investing heavily in the development of HFC technologies, an aerosol replacement 

for HFC-based MDIs is unlikely to be developed within the time frame of this analysis. Globally, the 

number of HFC MDIs used has grown to more than 100 million in 2001 (UNEP, 2002). Rather than 

developing new alternatives that use HFCs, some MDI patients may turn to DPIs, oral medication, or 

other NIK alternatives. In 2001, the number of multidose DPIs used worldwide was estimated at 65 

million (UNEP, 2002).2 This analysis examines the option of further replacing HFC-based MDIs with DPIs 

because of its technical feasibility and demonstrated success in the MDI market. 

DPIs are a viable option with most anti-asthma drugs, although they are not successful with all 

patients or all drugs. Micronised dry powder can be inhaled and deposited in the lungs from DPIs as 

with MDIs, but only in patients who are able to inhale robustly enough to transport the powder to the 

lungs. DPIs are not suitable for persons with severe asthma or for young children. Unlike MDIs, 

powdered drug particles contained in DPIs tend to aggregate and may cause problems in areas with hot 

and humid climates (March Consulting Group, 1999; UNEP, 2002). Other issues that doctors and patients 

consider when choosing a treatment device include the patient’s manual dexterity, ability to adapt to a 

new device, and perception of the effectiveness of the medicine, and the taste of any added ingredients 

(Price et al., 2004). It is important to note that the choice of treatment, including the type of propellant 

used in MDIs, is a medical decision involving the pharmaceutical industry, FDA or other regulatory 

authority, and ultimately doctors and their patients. Doctors and their patients will be involved in 

selecting the method of therapy, treatment regimen, and type of device(s) and active ingredients(s) that 

will prove most effective for particular individuals (IPAC, 1999). 

In 1998, DPI use was estimated to represent 17 percent of all inhaled medication (i.e., inhaler units) 

worldwide and had increased to 27 percent by 2002 (UNEP, 2002). DPIs may represent a viable 

alternative, as suggested by their increased use in Europe; for example, in Holland they account for more 

than 65 percent of inhaled medication (UNEP, 2002). The use of newly available DPIs is on the rise in the 

United States, where DPIs made up 14 percent of the total U.S. market share as of mid-2002 (UNEP, 2002). 

There is also a trend toward developing a broad range of oral treatments that would be swallowed, rather 

than inhaled and may be introduced over the next 10 to 20 years. These new medications may affect MDI 

use, although they will not likely replace inhaled MDI therapy entirely. 

This analysis assumes that DPIs are technically applicable3 to all HFC emissions from MDIs. 

However, because of the limitations in their use for severe asthma patients and young children, and the 

difficulties experienced in hot and humid climates, this analysis assumes a global incremental maximum 

market penetration into the HFC-based MDI market of 0 percent in 2005, increasing up to 50 percent in 

2020 (Table 5-3). DPIs do not use HFCs; hence, they have a 100 percent reduction efficiency. To the extent 

 

2 Multiple-dose DPIs contain premeasured doses that provide treatment for a day or up to 1 month. Single-dose DPIs 

are also available for which only one dose can be loaded at a time (UNEP, 2002). 

3 In this report, the term “technically applicable” refers to the emissions to which an option can theoretically be 

applied. Because DPIs can eliminate emissions from MDIs, they are technically applicable to all MDI emissions but 

are not technically applicable to non-MDI emissions. Other factors will affect their application and the market 

penetration assumed in this analysis. 
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GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES IV-109

that health and technical concerns are adequately met, a transition in inhalation therapy away from 

propellant MDIs and toward NIK alternatives may occur over the next 10 to 20 years. The rapidity at 

which these changes will occur depends on product development cycles (generally about 10 years), costeffectiveness, and manufacturing capacity (UNEP, 1999). 

Non-MDI: Replacement with Lower GWP HFCs 

Replacing higher GWP HFCs, such as HFC-134a, with a lower GWP HFC, such as HFC-152a, has the 

potential to greatly reduce emissions from the non-MDI aerosols sector. HFC-134a is the primary 

nonflammable propellant in certain industrial products. HFC-152a possesses only moderate flammability 

hazards and might therefore be acceptable for some applications (UNEP, 2002) but may present problems 

for other applications. This analysis assumes that converting to HFC-152a is technically applicable to all 

emissions of HFC-134a from the non-MDI baseline but is only adopted by some users. Non-MDI 

emissions of HFC-134a are calculated by the Vintaging Model to be 83 percent of total GWP-weighted 

non-MDI aerosol emissions. As shown in Table 5-3, the incremental maximum market penetration of this 

alternative is assumed to increase from 10 percent in 2005 to 50 percent in 2020. Because HFC-152a has a 

GWP of 140 (versus a GWP of 1,300 for HFC-134a), this substitution has an emissions reduction efficiency 

of 89.2 percent (i.e., the difference of the GWPs divided by the GWP of HFC-134a). 

Non-MDI: Replacement with NIK Alternatives 

NIK aerosol replacements include finger/trigger pumps, powder formulations, sticks, rollers, 

brushes, nebulizers, and bag-in-can/piston-can systems. These systems often prove to be better and more 

cost-effective options than HFC-propelled aerosols, particularly in areas where a unique HFC property is 

not specifically needed for a certain end-use. NIKs already occupy a sizable share of markets where they 

were introduced during the initial CFC phaseout. Since NIK products have already assumed much of the 

available non-MDI HFC aerosol market share, an incremental maximum market penetration of 5 percent 

was assumed in 2005 and 10 percent for years 2010, 2015, and 2020 (see Table 5-3). The analysis assumes 

that this option is technically applicable to all non-MDI emissions and has a reduction efficiency of 100 

percent. The GWP of 538 was used to represent both HFCs being abated and was calculated using the 

weighted average of the U.S. HFC-134a and HFC-152a baseline emissions. 

Non-MDI: Replacement with Hydrocarbon Aerosol Propellants 

HC aerosol propellants are usually mixtures of propane, butane, and isobutane. Their primary 

advantage lies in their affordability; the price of HC propellants is less than one-tenth that of HFCs. The 

main disadvantages of HC aerosol propellants are flammability and VOC emissions concerns. HCs 

contribute to ground-level ozone and smog and therefore may be regulated in some areas. In applications 

and markets where flammability and/or VOC emissions are less of a concern, HCs already hold a sizable 

share. Since HC aerosol propellants have already penetrated a significant amount of the market, further 

penetration is limited because of flammability and VOC concerns. Hence, this analysis assumes an 

incremental maximum market penetration of 5 percent in 2005, expanding to 10 percent in later years. 

The analysis also assumes that converting to HCs is technically applicable to all non-MDI emissions, but 

that various factors including the flammability of HCs will limit the market penetration of this option. 

The reduction efficiency of this abatement option is taken to be 100 percent, since the HFC is completely 

replaced by an HC propellant with a very low GWP. The GWP of 538 was used to represent both HFCs 

being abated and was calculated using the U.S. weighted average of the HFC-134a and HFC-152a 

baseline emissions. 
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IV-110 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

IV.5.3.2 Summary of Technical Applicability, Market Penetration, and Costs of Abatement 

Options 

Table 5-3 summarizes the technical applicability and incremental maximum market penetration of 

the aerosol options presented in the discussions above. 

Table 5-3: Technical Applicability and Incremental Maximum Market Penetration of Aerosol Options 

(Percent)a

Incremental Maximum Market Penetration 

Option 

Technical Applicability 

(All Years) 2005 2010 2015 2020 

DPI (MDI)b 100% 0% 5% 20% 50% 

HFC to HC (non-MDI) 100% 5% 10% 10% 10% 

HFC to NIK (non-MDI) 100% 5% 10% 10% 10% 

HFC-134a to HFC-152a (non-MDI) 83%c 10% 25% 35% 50% 

a Assumed maximum market penetration of options is presented as a percentage of total sector emissions for which the options are applicable. 

The baseline market penetration is assumed to be zero to assess the emissions reductions possible due to increased use of each option. 

b Assumptions are separated by the line to reflect that the MDI option addresses different baseline emissions than the non-MDI options. c Based on percentage of non-MDI aerosol emissions as determined by the Vintaging Model. 

To calculate the percentage of emissions reductions off the applicable (i.e., MDI or non-MDI) aerosols 

baseline for each abatement option, the technical applicability, is multiplied by the market penetration 

value, and by the reduction efficiency of the option. For example, to determine the percentage reduction 

off the 2020 baseline for the conversion of HFC-134a aerosols to HFC-152a, the following calculation is 

performed: 

Technical applicability x Market penetration in 2020 x Reduction efficiency 

83% x 50% x 89.2% ≈ 37.0% 

Thus, using the assumptions in this analysis, converting from HFC-134a to HFC-152a could reduce 

over one-third of the non-MDI emissions baseline in 2020. This value, along with the other emissions 

reduction potentials, is shown in Table 5-4. 

Table 5-4: Emissions Reductions Off the Total Applicable Aerosols Baseline (Percent) 

Option 2005 2010 2015 2020 

DPI (MDI)a 0.0 5.0 20.0 50.0 

HFC to HC (non-MDI) 5.0 10.0 10.0 10.0 

HFC to NIK (non-MDI) 5.0 10.0 10.0 10.0 

HFC-134a to HFC-152a (non-MDI) 7.4 18.5 25.9 37.0 

a Calculated percentages are separated by the line to reflect that the MDI option addresses different baseline emissions than the non-MDI 

options. 
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GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES IV-111

Table 5-5 summarizes the cost assumptions used for the aerosol options presented in the discussion 

above. 

Table 5-5: Summary of Abatement Option Cost Assumptions 

Option 

Time 

Horizon 

(Years) Unit of Costs 

Base OneTime Cost 

(2000$) 

Base 

Annual 

Cost 

(2000$) 

Base 

Annual 

Savings 

(2000$) 

Net Annual 

Costs 

(2000$/yr) 

DPI (MDI) 15 Per metric ton of abated 

substance 

$0 $571,400 $0 $571,400 

HFC to HC (NonMDI) 10 Per 10,000,000cans/yr 

requiring 2 oz. propellant 

each 

$325,000 $0 $2,001,456 –$2,001,456 

HFC to NIK 

(Non-MDI) 

10 Per 10,000,000 cans/yr 

requiring 2 oz. propellant 

each 

$250,000 $500,000 $2,343,458 –$1,843,458 

HFC-134a to 

HFC-152a (NonMDI) 

10 Per 10,000,000 cans/yr 

requiring 2 oz. propellant 

each 

$500,000 $0 $1,090,257 –$1,090,257 

IV.5.4 Results 

IV.5.4.1 Data Tables and Graphs 

Tables 5-6 through 5-9 provide a summary of the potential emissions reduction opportunities at 

associated breakeven costs in 15-dollar increments at a 10 percent discount rate (DR) and 40 percent tax 

rate (TR). Tables 5-6 and 5-7 present the results for MDI Aerosols, for 2010 and 2020, respectively. As 

shown, in 2010 and 2020, emissions reduction opportunities are only available at a breakeven cost greater 

than 60 dollars per tCO2eq for all regions. A world total emissions reduction of 0.55 MtCO2eq is projected 

by 2010 and 10.06 MtCO2eq by 2020, both at a breakeven cost greater than $60/tCO2eq. 

Tables 5-8 and 5-9 present the results for the Non-MDI Aerosols sector for 2010 and 2020, 

respectively. In contrast to the MDI aerosol sector, the non-MDI sector emissions reduction opportunities 

are available at the lowest breakeven cost of $0/tCO2eq for several regions. A total emissions reduction of 

12.6 MtCO2eq is projected by 2010 and 22.54 MtCO2eq by 2020, both at a breakeven cost below 1 dollar 

per tCO2eq. 

In Table 5-10, the costs, in 2000$, to reduce tCO2eq are presented for a discount rate scenario of 10 

percent and a tax rate of 40 percent. Within the options that address non-MDI emissions, the results are 

ordered by increasing costs per tCO2eq. Additionally, the emissions reduced by the option, in MtCO2eq 

and percent of the aerosols (either MDI or non-MDI) baseline, as well as cumulative totals of these two 

figures are presented. 
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IV-112 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

Table 5-6: Country/Regional Emissions Reductions in 2010 and Breakeven Costs for MDI Aerosols at 10% 

Discount Rate, 40% Tax Rate ($/tCO2eq) 

2010 

Country/Region $0 $15 $30 $45 $60 >$60 

Africa 0.00 0.00 0.00 0.00 0.00 0.02 

Annex I 0.00 0.00 0.00 0.00 0.00 0.43 

Australia/New Zealand 0.00 0.00 0.00 0.00 0.00 0.01 

Brazil 0.00 0.00 0.00 0.00 0.00 0.00 

China 0.00 0.00 0.00 0.00 0.00 0.04 

Eastern Europe 0.00 0.00 0.00 0.00 0.00 0.01 

EU-15 0.00 0.00 0.00 0.00 0.00 0.14 

India 0.00 0.00 0.00 0.00 0.00 0.01 

Japan 0.00 0.00 0.00 0.00 0.00 0.05 

Mexico 0.00 0.00 0.00 0.00 0.00 0.01 

OECD Annex I 0.00 0.00 0.00 0.00 0.00 0.06 

OECD 0.00 0.00 0.00 0.00 0.00 0.38 

Russian Federation 0.00 0.00 0.00 0.00 0.00 0.06 

South & SE Asia 0.00 0.00 0.00 0.00 0.00 0.02 

United States 0.00 0.00 0.00 0.00 0.00 0.14 

World Total 0.00 0.00 0.00 0.00 0.00 0.55 

EU-15 = European Union; OECD = Organisation for Economic Co-operation and Development. 

Table 5-7: Country/Regional Emissions Reductions in 2020 and Breakeven Costs for MDI Aerosols at 10% 

Discount Rate, 40% Tax Rate ($/tCO2eq) 

2020 

Country/Region $0 $15 $30 $45 $60 >$60 

Africa 0.00 0.00 0.00 0.00 0.00 0.43 

Annex I 0.00 0.00 0.00 0.00 0.00 6.91 

Australia/New Zealand 0.00 0.00 0.00 0.00 0.00 0.18 

Brazil 0.00 0.00 0.00 0.00 0.00 0.08 

China 0.00 0.00 0.00 0.00 0.00 1.08 

Eastern Europe 0.00 0.00 0.00 0.00 0.00 0.22 

EU-15 0.00 0.00 0.00 0.00 0.00 1.88 

India 0.00 0.00 0.00 0.00 0.00 0.29 

Japan 0.00 0.00 0.00 0.00 0.00 0.82 

Mexico 0.00 0.00 0.00 0.00 0.00 0.34 

Non-OECD Annex I 0.00 0.00 0.00 0.00 0.00 0.89 

OECD 0.00 0.00 0.00 0.00 0.00 6.40 

Russian Federation 0.00 0.00 0.00 0.00 0.00 0.77 

South & SE Asia 0.00 0.00 0.00 0.00 0.00 0.39 

United States 0.00 0.00 0.00 0.00 0.00 2.74 

World Total 0.00 0.00 0.00 0.00 0.00 10.06 

EU-15 = European Union; OECD = Organisation for Economic Co-operation and Development. 
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GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES IV-113

Table 5-8: Country/Regional Emissions Reductions in 2010 and Breakeven Costs for Non-MDI Aerosols at 

10% Discount Rate, 40% Tax Rate ($/tCO2eq) 

2010 

Country/Region $0 $15 $30 $45 $60 >$60 

Africa 0.01 0.01 0.01 0.01 0.01 0.01 

Annex I 12.56 12.56 12.56 12.56 12.56 12.56 

Australia/New Zealand 0.34 0.34 0.34 0.34 0.34 0.34 

Brazil 0.00 0.00 0.00 0.00 0.00 0.00 

China 0.01 0.01 0.01 0.01 0.01 0.01 

Eastern Europe 1.13 1.13 1.13 1.13 1.13 1.13 

EU-15 4.55 4.55 4.55 4.55 4.55 4.55 

India 0.00 0.00 0.00 0.00 0.00 0.00 

Japan 0.00 0.00 0.00 0.00 0.00 0.00 

Mexico 0.00 0.00 0.00 0.00 0.00 0.00 

Non-OECD Annex I 2.12 2.12 2.12 2.12 2.12 2.12 

OECD 10.45 10.45 10.45 10.45 10.45 10.45 

Russian Federation 1.61 1.61 1.61 1.61 1.61 1.61 

South & SE Asia 0.00 0.00 0.00 0.00 0.00 0.00 

United States 4.67 4.67 4.67 4.67 4.67 4.67 

World Total 12.60 12.60 12.60 12.60 12.60 12.60 

EU-15 = European Union; OECD = Organisation for Economic Co-operation and Development. 

Table 5-9: Country/Regional Emissions Reductions in 2020 and Breakeven Costs for Non-MDI Aerosols at 

10% Discount Rate, 40% Tax Rate ($/tCO2eq) 

2020 

 Country/Region $0 $15 $30 $45 $60 >$60 

Africa 0.01 0.01 0.01 0.01 0.01 0.01 

Annex I 22.46 22.46 22.46 22.46 22.46 22.46 

Australia/New Zealand 0.61 0.61 0.61 0.61 0.61 0.61 

Brazil 0.00 0.00 0.00 0.00 0.00 0.00 

China 0.03 0.03 0.03 0.03 0.03 0.03 

Eastern Europe 2.25 2.25 2.25 2.25 2.25 2.25 

EU-15 7.60 7.60 7.60 7.60 7.60 7.60 

India 0.01 0.01 0.01 0.01 0.01 0.01 

Japan 0.00 0.00 0.00 0.00 0.00 0.00 

Mexico 0.01 0.01 0.01 0.01 0.01 0.01 

Non-OECD Annex I 4.12 4.12 4.12 4.12 4.12 4.12 

OECD 18.36 18.36 18.36 18.36 18.36 18.36 

Russian Federation 3.11 3.11 3.11 3.11 3.11 3.11 

South & SE Asia 0.01 0.01 0.01 0.01 0.01 0.01 

United States 8.43 8.43 8.43 8.43 8.43 8.43 

World Total 22.54 22.54 22.54 22.54 22.54 22.54 

EU-15 = European Union; OECD = Organisation for Economic Co-operation and Development. 
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IV-114 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

Table 5-10: World Breakeven Costs and Emissions Reductions in 2020 for Aerosolsa

Reduction 

Option 

Cost 

(2000$/tCO2eq) 

DR=10%, TR=40% 

Emissions 

Reduction of 

Option 

(MtCO2eq) 

Reduction 

from 2020 

Baseline (%) 

Cumulative 

Reductions 

(MtCO2eq) 

Cumulative 

Reduction from 

2020 Baseline (%) 

DPI $439.54 10.06 50.0% 10.06 50.0% 

HFC to HC –$6.34 3.95 10.0% 3.95 10.0% 

HFC to NIK –$5.87 3.95 10.0% 7.91 20.0% 

HFC-134a to 152a –$1.07 14.64 37.0% 22.54 57.0% 

a Results are separated by the line to reflect that the MDI option addresses different baseline emissions than the non-MDI options. 

Figures 5-3 and 5-4 display the MDI aerosol international marginal abatement curves by region for 

2010 and 2020, respectively. 

Figure 5-3: 2010 MAC for MDI Aerosols, 10% Discount Rate, 40% Tax Rate 

EU-15 = European Union; OECD = Organisation for Economic Co-operation and Development. 
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GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES IV-115

Figure 5-4: 2020 MAC for MDI Aerosols, 10% Discount Rate, 40% Tax Rate 

EU-15 = European Union; OECD = Organisation for Economic Co-operation and Development. 

Figures 5-5 and 5-6 display the non-MDI aerosol international MACs by region for 2010 and 2020, 

respectively. 

Figure 5-5: 2010 MAC for Non-MDI Aerosols, 10% Discount Rate, 40% Tax Rate 

EU-15 = European Union; OECD = Organisation for Economic Co-operation and Development.
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IV-116 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

Figure 5-6: 2020 MAC for Non-MDI Aerosols, 10% Discount Rate, 40% Tax Rate 

EU-15 = European Union; OECD = Organisation for Economic Co-operation and Development. 

IV.5.4.2 Uncertainties and Limitations 

This section focuses on the uncertainties and limitations associated with the cost estimates presented 

in this analysis. The significant areas of uncertainty are in how costs and the maximum market 

penetrations for these mitigation technologies may vary internationally. The analysis is currently limited 

in the lack of this specificity on region-specific cost analysis and maximum market penetration estimates. 

Additionally, the following uncertainties should be noted: 

• Non-MDI: Replacement with NIK Alternatives. There is uncertainty surrounding the significant 

variability of one-time costs associated with the financial components of projects targeting NIK 

replacements for HFC-containing aerosol products. As such, the assumption used is limited to 

the current understanding of this variability.

• Non-MDI: Replacement with Hydrocarbon Aerosol Propellants. The major limitation 

associated with this option is regarding the annual costs. The analysis does not quantify any 

annual labor costs that may be incurred to ensure good handling practices of hydrocarbons 

(considered HAPs); regular maintenance on fire prevention devices such as fire detection 

systems, sprinklers, and shut-off valves; and proper safety training for employees (UNEP, 2002). 

IV.5.5 Summary 

This analysis considers four mitigation options: MDI replacement with DPIs, non-MDI replacement 

with lower GWP HFCs, non-MDI replacement with NIK alternatives, and non-MDI replacement with HC 

aerosol propellants. The first option has the potential to abate emissions from the MDI baseline, while the 

latter three options have the potential to abate emissions from the non-MDI baseline. 
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GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES IV-117

IV.5.5.1 MDI Aerosols 

Global baseline HFC emissions from MDI aerosols are estimated to grow from 2.9 to 20.1 MtCO2eq 

between 2000 and 2020. In 2020, the Annex I region is estimated to be responsible for approximately 69 

percent of the baseline emissions and represents the highest emissions growth from the MDI baseline, 

from 2.8 MtCO2eq in 2000 to 13.8 MtCO2eq in 2020 (see Table 5-1). 

As Table 5-10 illustrates, converting from HFC MDIs to DPIs is not a cost-effective abatement 

option—the estimated cost worldwide is more than $400 dollars per tCO2eq at a 10 percent discount rate 

and 40 percent tax rate—although the option may be implemented for other reasons (e.g., preferred 

delivery system by a pharmaceutical company). At this cost, this option could abate 50 percent of global 

MDI emissions, or 10.06 MtCO2eq, annually by 2020. The costs per tCO2eq for each region are equivalent 

because available data on costs for abatement technologies were not scaled to reflect potential differences 

in the costs internationally. Additional research may be performed to determine actual variability in costs 

across regions. 

IV.5.5.2 Non-MDI Aerosols 

Baseline HFC emissions from non-MDI aerosols are estimated to grow from 24.2 MtCO2eq to 39.5 

MtCO2eq globally for the years 2000 through 2020. In 2020, the majority of emissions is from the Annex I 

region, which represents the highest emissions growth from the non-MDI baseline, from 24.1 MtCO2eq in 

2000 to 39.4 MtCO2eq in 2020 (see Table 5-2). 

As shown in Table 5-10, the greatest emissions reduction opportunities in all of the regions analyzed 

may result from converting to HC, at a cost savings of $6.34 per tCO2eq at a 10 percent discount rate and 

40 percent tax rate. The other two options, converting to NIK and HFC-152a, also represent a cost savings 

of $5.87 and $1.07 per tCO2eq under the same discount and tax rate scenario, respectively. Globally, 22.54 

MtCO2eq or 57 percent of global emissions from non-MDI aerosols, can be reduced in 2020 at a cost below 

$0.00 per tCO2eq. As with MDI aerosols, costs per tCO2eq for all regions are equivalent because available 

data on costs for abatement technologies were not scaled to reflect potential differences in the costs 

internationally. Additional research may be performed to determine actual variability in costs across 

regions. 

IV.5.6 References 

Arthur D. Little, Inc. 1999. Global Comparative Analysis of HFC and Alternative Technologies for Refrigeration, 

Air-Conditioning, Foam, Solvent, Aerosol Propellant, and Fire Protection Applications. Final report to the 

Alliance for Responsible Atmospheric Policy. Reference Number 49648. Arthur D. Little, Inc. 

Diversified CPC. May 2006. Personal communication between Bill Frauenheim of Diversified CPC and 

Mollie Averyt of ICF International. 

Diversified CPC. June 2004. Personal communication between Bill Frauenheim of Diversified CPC and 

Mollie Averyt of ICF Consulting. 

Dupont. July 2000. Personal communication between John Lueszler of Dupont and ICF Consulting. 

Dupont. September 2005. Personal communication between Linda Calvarese of Dupont and ICF 

Consulting. 

Ecofys. 2000. Abatement of Emissions of Other Greenhouse Gases: Engineered Chemicals. Prepared for the 

International Energy Agency Greenhouse Gas Research and Design Programme. Ecofys. 

Enviros March. 2000. Study on the Use of HFCs for Metered Dose Inhalers in the European Union. 

Commissioned by the International Pharmaceutical Aerosol Consortium (IPAC). Eviros March. 
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IV-118 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

International Pharmaceutical Aerosol Consortium (IPAC). 1999. Ensuring Patient Care, 2nd Edition. 

Available at <http://www.ipacmdi.com/Ensuring.html>. 

March Consulting Group. 1999. UK Emissions of HFCs, PFCs, and SF6 and Potential Emissions Reduction 

Options: Final Report. March Consulting Group. 

Nardini, Geno. May 2002. Personal communication between Geno Nardini and Iliriana Mushkolaj of ICF 

Consulting. 

Price, D., E. Valovirta, and J. Fischer. 2004. “The Importance of Preserving Choice in Inhalation Therapy: 

The CFC Transition and Beyond.” Journal of Drug Assessment 7, 45-61. 

United Nations Environment Programme (UNEP). 1999. “The Implications to the Montreal Protocol of 

the Inclusion of HFCs and PFCs in the Kyoto Protocol.” UNEP HFC and PFC Task Force of the 

Technology and Economic Assessment Panel (TEAP). 

United Nations Environment Programme (UNEP). 2002. “2002 Report of the Aerosols, Sterilants, 

Miscellaneous Uses and Carbon Tetrachloride Technical Options Committee: 2002 Assessment.” 

UNEP HFC and PFC Task Force of the Technology and Economic Assessment Panel (TEAP). 

U.S. Environmental Protection Agency (USEPA). 2001. U.S. High GWP Gas Emissions 1990–2010: 

Inventories, Projections, and Opportunities for Reductions. EPA #000-F-97-000. Washington, DC: 

USEPA. 

X-rates.com. 2006. Available at <www.x-rates.com>. Accessed January 2006. 
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GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES IV-119

IV.6 HFC Emissions from Fire Extinguishing 

IV.6.1 Introduction 

ire-extinguishing applications can be divided into two categories: portable fire extinguishers 

(e.g., streaming applications) that originally used halon 1211 and total flooding applications 

that originally used halon 1301 or halon 2402 (USEPA, 2004; March Consulting Group, 1998, 

1999). Historically, SF6, another high-GWP gas, was used in select fire-extinguishing systems, such as for 

system discharge testing purposes by the U.S. Navy. For the most part, however, SF6 is no longer used in 

any capacity in the fire-protection sector. 

The principal greenhouse gases used in and emitted from the fire-extinguishing sector are 

hydrofluorocarbons (HFCs) (HFC-227ea, HFC-236fa, and HFC-23) and blends containing 

perfluoromethane (CF4). These gases have 100-year GWPs that range from 2,900 to 11,700 (IPCC, 1996). 

These high-GWP gases are substitutes for halons, ozone-depleting substances (ODSs) that have been, 

and in many countries still are, widely used in fire-extinguishing applications. Although halons were 

produced in much lower volumes than other ODSs, they have extremely high ozone depletion potentials 

(ODPs) because of the presence of bromine, which reacts more strongly with ozone than chlorine. Halons 

have been used historically in fire-suppression and explosion-protection applications because they are 

electrically nonconductive, dissipate rapidly without residue, are safe for limited human exposure, and 

are extremely efficient in extinguishing most types of fires (USEPA, 1994). 

Portable fire extinguishers are most frequently used in offices, manufacturing and retail facilities, 

aerospace/marine applications, and homes. Market penetration of HFCs in this sector has been limited 

and is unlikely to grow or even keep pace with the growth in portable extinguishers (Wickham, 2003a). 

Perfluorocarbons (PFCs) have had a very small penetration in the portable fire extinguisher market. By 

2020, only one HFC, HFC-236fa, is expected to be used to a limited extent as a halon replacement in small 

segments of the portable extinguisher sector. Overall, portable applications represent a much smaller 

share of total fire-extinguishing sector greenhouse gas emissions than do total flooding applications, and 

the U.S. Environmental Protection Agency (USEPA) projects that their relative share of emissions will 

decrease over time, based on cost reasons outlined in Wickham (2002). 

The majority of HFC emissions associated with fire extinguishing come from its use as a replacement 

for some halon 1301 applications in the total flooding market. Total flooding systems are usually used to 

protect a variety of spaces, including the following: 

• electronic and telecommunications equipment, such as tape storage areas, computer facilities, 

telecommunications gear, medical facilities, control rooms in nuclear power plants, and air traffic 

control towers; 

• military applications, including aviation engine nacelles1

 and dry bays, naval engine 

compartments, and engine compartments and occupied crew spaces of ground combat vehicles; 

• oil production facilities; 

• flammable liquid storage areas; 

• engine nacelles and cargo bays of commercial aircraft; 

 

1 Nacelles are enclosed engine housings. 

F 
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• cultural institutions and museums; 

• records storage areas; 

• bank vaults; 

• warehouses; and 

• special facilities, such as research laboratories and military facilities. 

Halon 1301 was widely used in total flooding applications because of its unique features (Wickham, 

2002).2 Halon 1301 is a clean agent, meaning that it does not leave residue on equipment or in the 

protection enclosure after discharge. In addition, halon 1301 is safe for limited, acute human exposure at 

the concentration used for fire extinguishing. It is also very effective at extinguishing fires and works well 

over a broad temperature range. Because halon 1301 was inexpensive, and design and installation of 

halon 1301 systems were relatively simple compared with other fire-extinguishing systems, these systems 

reached almost all segments of the total flooding fire-extinguishing market. 

The alternatives to halon 1301 in total flooding applications can be categorized as in-kind, gaseous 

agent alternatives (i.e., halofluorocarbons, CO2, inert gases, fluorinated ketones) and NIK alternatives 

(i.e., dispersed and condensed aerosol extinguishing systems, water sprinklers, water mist, foam,3 or inert 

gas generators). In most Annex I countries, halofluorocarbon HFC-227ea has emerged as the primary 

replacement for halon 1301 in total flooding applications that require clean agents. Other HFCs, such as 

HFC-23, HFC-236fa, and HFC-125, have been evaluated and determined to be safe for limited, acute 

human exposure but are used in smaller amounts as a result of environmental,4

 technical, and economic 

concerns. For example, use of HFC-125 has been limited to normally unoccupied specialty applications, 

such as aviation engine nacelles. However, over the next 20 years, HFC-23 and HFC-125 are expected to 

only gain a strong foothold in the Russian Federation, based on confidential information collected for this 

report from members of UNEP’s Halon Technical Options Committee (HTOC). A small number of 

telecommunications facilities in Eastern Europe historically used PFCs (C3F8 and C4F10). In the United 

States, PFC use in fire suppression is very limited and is expected to tail off—the U.S. manufacturer of 

PFCs for fire suppression withdrew these agents from the market a number of years ago because of 

concern about their high GWP. In addition, HCFCs have historically been used as halon 1301 

replacements, particularly in Eastern and Southern Europe. Over time, the use of HCFCs and PFCs in 

total flooding applications is expected to be phased out and replaced primarily with HFCs, in addition to 

other alternatives. 

Available in-kind, nonhalocarbon alternatives in total flooding applications include CO2 systems, 

used primarily in marine and industrial applications; fluorinated ketones; and inert gas systems, which 

contain nitrogen or argon or blends of these gases, sometimes incorporating CO2 as a third component. 

Inert gas systems have become the dominant halon 1301 replacement in many parts of Europe, most 

notably in northern European countries. 

Available NIK alternatives and technologies include powdered aerosols, water sprinklers, water mist 

systems, foams, and combinations of these systems, such as aerosols with a halocarbon agent or water 

mist with a gaseous agent or with foam. 

 

2 The Russian Federation is an exception; it has historically relied on halon 2402, not halon 1301. 

3 Foams can be protein based or synthetic based. Some synthetic-based foams contain fluorocarbons. 

4 Whereas HFC-125 has a GWP of 2,800, approximately the same as HFC-227ea (GWP of 2,900), the other gases have 

much higher GWPs. The GWP of HFC-236fa is 6,300, and the GWP of HFC-23 is 11,700. 
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GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES IV-121

IV.6.2 Baseline Emissions Estimates 

IV.6.2.1 Emissions Estimating Methodology 

Description of Methodology 

Specific information on how the emissions model was used to calculate ODS substitute emissions 

from all sectors producing fire-protection emissions is described below. 

The USEPA uses a detailed Vintaging Model of ODS-containing equipment and products to estimate 

the use and emissions of ODS substitutes (HFCs) in the United States. Emissions estimates for non-U.S. 

countries are derived using country-specific ODS consumption estimates, as reported under the Montreal 

Protocol, in conjunction with Vintaging Model output for the fire-extinguishing sector. For countries for 

which sufficient data were available, country-specific Vintaging Models were developed. 

This analysis first incorporates estimates of the consumption of ODSs by country, as provided by 

UNEP (1999). Estimates for EU were provided in aggregate, and GDP was used as a proxy to distribute 

consumption among the individual member nations. 

Emissions Equations 

This analysis assumes that total emissions from leakage, accidental discharges, and fire extinguishing, 

in aggregate, equal a percentage of the total quantity of chemical in operation at a given time. For 

modeling purposes, the fire-extinguishing agent is assumed to be released at a constant rate for an 

average equipment lifetime. 

Ej = r × ̕ Qcj–i+1 for i=1k (6.1) 

where 

E = Emissions. Total emissions of a specific chemical in year j for fire-extinguishing 

equipment, by weight. 

r = Percentage released. Average annual percentage of the total chemical in operation that is 

emitted to the atmosphere. 

Qc = Quantity of chemical. Total amount of a specific chemical used in new fire-extinguishing 

equipment one lifetime (k) ago (e.g., j – k + 1), by weight. 

i = Counter. Runs from 1 to lifetime (k). 

j = Year of emissions. 

k = Lifetime. The average lifetime of the equipment. 

Estimates used for the percentage released, r, and lifetime of equipment, k, can have a significant 

effect on the resulting emissions estimates. For this analysis, the U.S. Vintaging Model assumed that the 

percentage released, r, or the emissions factor, is 2 percent for both the total flooding sector (Verdonik 

and Robin, 2004) and the streaming sector. These estimates were chosen to account, on average, for all 

emissions from servicing, leaks, accidental/false discharges, system decommissioning, or intentional 

discharges to extinguish fires. The U.S. Vintaging Model also assumes equipment lifetime, k, for 

streaming and flooding applications to be 10 and 20 years, respectively. 

Regional Variations/Adjustments 

To estimate baseline emissions, information collected on current and projected market 

characterizations of international total flooding sectors was used to create country-specific versions of the 
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IV-122 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

Vintaging Model (i.e., country-specific ODS substitution patterns). Information on the current and 

projected relative market size of halon substitutes was obtained for Australia, Brazil, China, India, Japan, 

the Russian Federation, and UK, as provided by HTOC members from those countries.5

 General 

information was also collected on Northern, Southern, and Eastern Europe. For all other non-U.S. 

countries, baseline emissions information from some of these countries was used to adjust substitution 

patterns, as described below: 

• Eastern Europe was used as a proxy for the countries in FSU and CEITs except the Russian 

Federation, where specific information was available. 

• Australia was used as a proxy for New Zealand. 

• Brazil was used as a proxy for countries in Latin America and the Caribbean. 

• India was used as a proxy for all other developing countries. 

For all other non-U.S. Annex I countries, the U.S. ODS substitution pattern was used as a proxy.6 In 

addition, an adjustment factor was applied to EU countries to account for European Regulation 2037/2000 

on Substances that Deplete the Ozone Layer, which mandated the decommissioning of all halon systems 

and extinguishers in the EU by the end of 2003 (with the exception of those applications that are defined 

as critical uses) (Europa, 2003). To reflect this, the methodology assumes that all halon systems in the EU 

were decommissioned by 2004.7

 

IV.6.2.2 Baseline Emissions 

The resulting baseline estimates of GWP-weighted HFC emissions developed for this report are 

summarized in Table 6-1 and Figure 6-1. Baseline emissions estimates are presented in million metric tons 

of carbon dioxide equivalents (MtCO2eq). The estimates of the global total flooding fire-protection market 

developed for this report are generally consistent with those in the Intergovernmental Panel on Climate 

Change/Technology and Economic Assessment Panel (IPCC/TEAP) (1999) report, which estimated that in 

the late 1990s, between 20 percent and 22 percent of systems that would formerly have used halons used 

HFCs, and that less than 1 percent used PFCs. 

 

5 Fire-protection experts in these countries provided confidential information on the status of national halon 

transition markets and average costs to install the substitute extinguishing systems in use (on a per volume of 

protected space basis) for 2001 through 2020. 

6 This analysis assumes that, of the new total flooding protection systems in which halons have been previously used 

in the United States, the market is currently made up of approximately 16 percent HFC-227ea, less than 1 percent 

HFC-23, 10 percent inert gas, and 74 percent other NIK agents. 

7 The use of halon in marine applications is unlikely to have met the 2004 phaseout deadline because these 

applications are also governed by regulations issued by the International Maritime Organization (IMO) and because 

many EU ships contained halon 1301 fire-suppression systems. However, because of a lack of available data on 

emissions from marine-based fire-protection systems as a percentage of the total EU fire-extinguishing sector, this 

analysis simply assumes full compliance with the EU regulation. 
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GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES IV-123

Table 6-1: Total Baseline HFC Emissions from Fire Extinguishing (MtCO2eq) 

Country/Region 2000 2010 2020 

Africa 0.1 0.3 0.6 

Annex I 1.1 3.8 5.8 

Australia/New Zealand 0.0 0.1 0.1 

Brazil 0.0 0.0 0.0 

China 0.3 2.0 4.9 

Eastern Europe 0.0 0.0 0.1 

EU-15 0.1 1.2 2.2 

India 0.0 0.0 0.1 

Japan 0.1 0.6 0.9 

Mexico 0.0 0.0 0.1 

Non-OECD Annex I 0.0 0.1 0.3 

OECD 1.1 4.1 6.3 

Russian Federation 0.0 0.1 0.3 

South & SE Asia 0.0 0.3 0.5 

United States 0.7 1.6 1.9 

World Total 1.7 7.4 13.7 

EU-15 = European Union; OECD = Organisation for Economic Co-operation and Development 

Figure 6-1: Baseline HFC Emissions from Fire Extinguishing by Region (MtCO2eq) 

CPA = Centrally Planned Asia; Non-EU FSU = non-European Union Former Soviet Union countries; OECD90+ = Organisation for Economic 

Co-operation and Development. 
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IV-124 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

This analysis assumes that systems designed to protect against Class A surface fire hazards represent 

an estimated 95 percent of the total flooding sector in all countries, and that the remaining 5 percent of 

the applications are designed to protect against Class B fire hazards (flammable liquids and gases).8

According to projected global average emissions estimates, emissions from systems that protect against 

Class A fire hazards will account for approximately 74 percent of the global total fire-extinguishing sector 

in 2005, 79 percent in 2010, 85 percent in 2015, and 87 percent in 2020. Table 6-2 presents the estimated 

global average breakout of total fire-sector HFC emissions by application, as estimated by the USEPA’s 

Vintaging Model. This assumed breakout was used to estimate the emissions reduction potential of the 

abatement options applicable to Class A or Class B total flooding sectors for all regions. 

Table 6-2: Assumed Breakout of Total GWP-Weighted Baseline Fire-Extinguishing Emissions (Percent) 

Annex I and Non-Annex I Countries 

2005 2010 2015 2020 

Flooding 78.0% 83.1% 89.5% 92.0% 

Class A emissions (95% total flooding) 74.1% 78.9% 85.0% 87.4% 

Class B emissions (5% total flooding) 3.9% 4.2% 4.5% 4.6% 

Streaming 22.0% 16.9% 10.5% 8.0% 

Total 100.0% 100.0% 100.0% 100.0% 

Note: Totals may not sum because of independent rounding. 

IV.6.3 Cost of HFC Emissions Reductions from Fire Extinguishing 

This section presents a cost analysis for achieving HFC emissions reductions from the baselines 

presented in Table 6-1. Each abatement option is described below, but costs are analyzed for only those 

options not assumed to occur in the baseline (or for which a larger market penetration than reflected in 

the baseline is believed to be possible) and for which adequate cost data are available. All cost analyses 

assume a 20-year project lifetime. To the extent possible, this analysis considered total equivalent 

warming impacts (TEWI) to account for the cost and greenhouse gas-emissions impacts of energy 

consumption (i.e., indirect emissions) associated with the heating/cooling of additional space needed to 

house alternative agents. However, because of data limitations, a full life-cycle analysis was not possible. 

For example, the cost and emissions impacts associated with manufacturing alternative agents and all 

system components were not assessed in this analysis, although they may potentially be significant. 

IV.6.3.1 Description and Cost Analysis of Abatement Options 

Because streaming applications account for a relatively small proportion of fluorocarbon use (e.g., 

HFC-236fa) in fire extinguishing, this cost analysis focuses only on abatement options for the total 

 

8 Wickham (2002) estimates that over 90 percent of the halon 1301 systems ever installed in the United States were 

designed to protect against hazards where the anticipated fire type was primarily Class A in nature, and that 

approximately 10 percent of the U.S. applications served by halon 1301 had hazardous materials of the Class B type. 

However, because much of the former halon 1301 Class B applications have been replaced by non-HFC alternatives 

(e.g., carbon dioxide), this analysis assumes that only 5 percent of HFC emissions from the total flooding sector are 

from Class B applications, and that the remaining 95 percent are from Class A applications. 
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GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES IV-125

flooding sector.9 In 2005, the majority of emissions from the fire-extinguishing sector are expected to have 

resulted from leaks and discharges (both accidental and intended use to extinguish fires) from total 

flooding applications. The options for reducing HFC emissions from the fire-protection sector include the 

use of alternative fire-protection agents and the use of alternative technologies and practices. Eight 

potential options are identified, but only the first three are explored further in the cost analysis: 

• inert gas, 

• water mist, 

• fluorinated ketone (FK-5-1-12), 

• carbon dioxide, 

• recovery and reuse of HFCs, 

• improved detection systems, 

• fine aerosols, and 

• inert gas generators. 

As described further below, available alternatives to reduce emissions in the fire-protection sector 

may not be technically or economically viable for all end-use applications. For example, military 

applications often have specialized needs that do not exist in other end-use applications. Applications 

that are space and/or weight constrained, such as marine and aviation applications, are more limited in 

their choice of agents. Electronic and telecommunication applications, which represent the largest use of 

HFCs in the total flooding sector, offer the greatest opportunities to apply alternatives, although some 

economic penalties and technical challenges may exist. 

The remainder of this section provides an overview of each abatement option—inert gas, water mist, 

and fluorinated ketone—and presents the assumptions and results of cost analyses. For reasons discussed 

further below, these options are assumed to be applicable only to new (not existing) total flooding 

systems, where “new” is defined as systems installed in 2005 or later. All costs are presented in 2000 

dollars. A detailed description of the cost and emissions reduction analysis for each option can be found 

in Appendix J for this chapter. 

Inert Gas Systems 

Inert gas systems extinguish fires using argon, nitrogen, or a blend of the two, sometimes 

incorporating CO2 as a third component (UNEP, 2001). Inert gas systems provide both fire protection and 

life safety/health protection equivalent to HFCs in most Class A (ordinary combustible) fire hazards, 

including electronics and telecommunications applications. 

Although inert gas systems are effective at extinguishing fires, their discharge time is slower than 

that of HFC systems—60 seconds or more compared with 10 to 15 seconds (Kucnerowicz-Polak, 2002). In 

areas where a rapidly developing fire is likely, inert gas systems are not recommended (UNEP, 2001; 

Kucnerowicz-Polak, 2002). Improved devices that recognize and extinguish fires before they have a 

chance to spread may help alleviate these concerns. Another limitation is that inert gas systems need a 

larger volume of agent to extinguish fires than do HFC systems. The weight-support structures and space 

 

9 The USEPA estimates that more than 90 percent of the halon replacement market in the streaming sector currently 

consists of NIK alternatives, while HFCs account for less than 5 percent of this market. By 2020, the USEPA projects 

that HFCs will account for an even smaller portion of the halon replacement market in the streaming sector. It is 

expected that the high cost of HFCs will ensure that they are used only where they are absolutely needed (i.e., in 

areas where cleanliness is an absolute necessity) (Wickham, 2002). 
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IV-126 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

needed for additional steel cylinders of gas may prohibit the retrofit of many existing HFC systems, such 

as those on small ships and in other applications where the system infrastructure is fixed. Extra storage 

space for cylinders may also mean extra space to heat and cool, which means more expense and energy 

consumption. 

This analysis assumes inert gas systems are technically applicable10 to emissions from total flooding 

systems designed for Class A fires. Because of the additional space requirements associated with inert gas 

systems, it is not assumed to be economically feasible to retrofit existing HFC Class A fire-extinguishing 

systems to this option. This analysis therefore assumes that this option is applicable only to new Class A 

applications (i.e., those installed in 2005 or later). Because of the additional space and weight 

requirements and the slower discharge times, market penetration rates reflect the assumption that this 

option cannot fully displace HFC use in new Class A total flooding applications. Furthermore, because 

this option entails additional costs (see discussion below), market penetration in non-Annex I countries is 

assumed to be 50 percent less than in Annex I countries for all years because of economic challenges faced 

by developing countries. Table 6-4 (Annex I countries) and Table 6-5 (non-Annex I countries) present the 

assumed market penetration rates of inert gas systems into new systems and as a percentage of total 

sector baseline emissions. 

Water Mist Systems 

Water mist systems use relatively small droplet sprays under low, medium, or high pressure to 

extinguish fires. These systems use specially designed nozzles to produce much smaller droplets than are 

produced by traditional water-spray systems or conventional sprinklers, so they use less water to 

extinguish a fire (UNEP, 2001; Wickham, 2002). Another benefit of water mist systems is that, in some 

applications (e.g., marine applications), they can be brought into action faster than HFC systems because 

there is less concern about applying water mist in situations where openings to the space are not all 

closed—which in turn leads to reduced fire damage. In addition, unlike HFC systems, which are usually 

limited to a single discharge of agent, most water mist systems have an unlimited water supply in landbased operations, and at least 30 minutes of potable water discharge followed by an unlimited amount of 

seawater for marine applications (Wickham, 2003b). 

To date, water mist systems have been used in shipboard accommodation, storage and machinery 

spaces, combustion turbine enclosures, flammable and combustible liquid machinery applications, and 

light and ordinary hazard sprinkler applications (UNEP, 2001). Water mist systems can provide 

equivalent fire protection and life safety/health protection for Class B fuel hazards, where lowtemperature freezing is not a concern. Systems designed to protect against Class B (flammable liquid) fire 

hazards are estimated to account for approximately 5 percent of the HFC total flooding market in the 

United States and were assumed to account for the same percentage in all non-U.S. countries (Wickham, 

2002). Water mist systems have also found acceptance in Class A applications but as replacements for 

water sprinklers, not HFCs. Therefore, this report does not consider water mist as an option for abating 

HFC emissions from Class A applications. 

Some barriers have impeded broad use of water mist systems. First, these systems have not proven 

effective in extinguishing small fires in spaces with volumes greater than 2,000 cubic meters (IMO, 2001; 

 

10 In this report, the term “technically applicable” refers to the emissions to which an option can be theoretically 

applied. Because inert gas systems are assumed to be used only in Class A fire total flooding applications, the 

technical applicability is 100 percent of the emissions associated with those types of systems. Other factors will affect 

the application of the option, for example to new or existing systems, and the market penetration assumed in this 

analysis. 
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GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES IV-127

Wickham, 2002). Additionally, because there is a nonlinear relationship between the volume of space and 

the amount of water mist needed to extinguish a given fire, and because this relationship (referred to as 

the “mechanism of extinguishment”) is not well understood, applications of water mist systems have 

been limited to those where fire test protocols have been developed, based on empirically tested system 

performance. Therefore, new applications may require empirical performance testing prior to installing 

such systems to ensure safety and obtain approval of the proper regulatory or standard-setting authority. 

Currently, an IMO working group is studying this situation and considering proposals that suggest an 

overhaul to the test methods and approval guidelines. Should IMO change its water mist requirements to 

something more flexible regarding the extinguishing of small fires in these sized spaces, it will make a 

difference in the future cost and, thus, market acceptance of water mist systems (Wickham, 2003b). In 

addition, the use of additives—such as salts or foam or a combination of these systems with gaseous 

agents—offers other options under investigation to improve system performance for specific applications. 

Many researchers and industry experts believe that solutions to these market barriers are well within 

reach (Wickham, 2002). 

Other market barriers for this option include additional space requirements for system storage 

compared with conventional HFC-227ea systems. Indeed, water mist systems require an estimated seven 

times more space than HFC-227ea (Wickham, 2003b). In addition, water mist systems used in marine 

applications are cost prohibitive for protecting spaces less than 3,000 cubic meters in size.11 

This analysis assumes that water mist systems are technically applicable to the emissions from total 

flooding systems designed to protect against Class B fires. Because of the additional space requirements 

associated with this option, it is assumed that water mist systems could not feasibly replace any existing 

HFC systems in Class B fire-protection applications and, therefore, are used only in new Class B total 

flooding applications (i.e., those installed in 2005 or later). 

This analysis assumes that the remaining technical constraints associated with water mist systems 

will gradually be overcome and that by 2020, in Annex I countries, water mist systems will reach full 

market penetration in all new Class B fire-suppression systems used to protect large spaces. Market 

penetration estimates for non-Annex I countries are assumed to be 50 percent less than those for 

developed countries, as a result of economic considerations. Table 6-3 and Table 6-4 present the 

maximum market penetrations assumed for this option. 

Fluorinated Ketone (FK-5-1-12) 

FK-5-1-12-mmy2 (also known as 1,1,1,2,2,4,5,5,5-nonafluoro-4-(trifluoromethyl)-3-pentanone, and 

commonly referred to as FK-5-1-12) is a fluorinated ketone with an atmospheric lifetime up to 2 weeks 

and a 100-year GWP of approximately 1 (ICF Consulting, 2003). This alternative received the USEPA’s 

Significant New Alternatives Policy (SNAP) approval as an acceptable replacement for halon 1301 in 

flooding applications at the end of 2002, and for halon 1211 in nonresidential streaming applications in 

early 2003. 

Compared with HFC-227ea total flooding systems, FK-5-1-12 systems are associated with slight space 

and weight penalties; when averaged across different-sized spaces, space penalties are on the order of 7 

 

11 This cost information is based on water mist systems employed under the current IMO requirements for marine 

systems, which are much more severe than the requirements for land-based systems. The use of water mist systems 

in nonmarine applications appears to be more cost competitive with other alternatives (Wickham, 2003a). 
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IV-128 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

percent,12 and weight penalties are approximately 17 percent—which could make its use in confined 

spaces (e.g., ships, aircraft) less attractive, although some marine installations have already been reported 

(Werner, 2004a).13 Moreover, because of its cost (see cost analysis below) and its relatively recent entry14

into this market, the extent of future commercial use of this option is not known. 

Although this option is not associated with major floor space penalties and appears not to suffer from 

any significant technical barriers, it is only assumed to be technically applicable in new Class A flooding 

applications (i.e., those installed in 2005 or later), because the cost analysis does not assess retrofit costs. 

Table 6-4 and Table 6-5 present the incremental maximum market penetration assumptions for this 

option, which project that this option will gain a foothold in the marketplace and after 2010 will outcompete inert gas systems in new Class A total flooding applications. Because of the reasons outlined 

above, this analysis conservatively assumes that market penetration will be low in early years, although 

others project higher sales (Werner, 2004b). Market penetration is assumed to be greater in Annex I 

countries than in non-Annex I countries because of economic considerations. 

Carbon Dioxide 

CO2 has been used for many decades in total flooding systems. Some of the hazards and equipment 

that CO2 systems protect are flammable liquid materials; electrical hazards such as transformers, 

switches, circuit breakers, rotating equipment, and electronic equipment; engines using gasoline and 

other flammable liquid fuels; ordinary combustibles such as paper, wood, and textiles; and hazardous 

solids (NFPA, 2000). Because of the lethal concentrations at which CO2 is required for use as a fireextinguishing agent, there have been concerns about incidences of deaths and injuries attributed to 

exposure to this agent (USEPA, 2000; Wickham, 2003b). In 2003, the NFPA Technical Committee on 

NFPA 12: Standard for Carbon Dioxide Fire Extinguishing Systems reviewed a proposal to change the 

standard to prohibit use of these systems in normally occupied areas (Wickham, 2003b). The IMO’s Safety 

of Life at Sea (SOLAS) standard does not prohibit the use of CO2 in normally occupied areas but calls for 

the use of suitable alarms and mandates against the use of automatic release of the fire-extinguishing 

medium, as noted in Carbon Dioxide as a Fire Suppressant: Examining the Risks (USEPA, 2000). IMO has also 

considered whether to prohibit use of CO2 systems in occupied areas as part of that organization’s broad 

review of the current performance testing requirements for all shipboard fire-extinguishing systems 

(IMO, 2003; Wickham, 2003b). 

As one of the oldest fire-extinguishing agents in use, and as a more economical option than HFCs, 

CO2 has developed its own niche market in narrow-use total flooding applications. Whereas CO2 could 

and does replace some halon use where permitted by regulations, this analysis assumes that CO2 would 

be selected as a first-choice replacement of halon, not as a second transition, after more costly HFCs. For 

example, the majority of U.S. ship owners have shifted from halon 1301 to CO2 for mandatory engine 

room protection for new ships (Wickham, 2002). For this reason, any use of CO2 is assumed to occur in 

the baseline and not as an option to replace HFC systems. It is therefore not considered in the cost 

analysis.

 

12 Smaller spaces actually have no footprint penalty, but larger spaces (approximately equal to or greater than 1,000 

cubic meters) have space penalties of roughly 14 percent. 

13 It has been reported that the space penalty is only associated with use in large systems, and that the weight penalty 

has not proven to be an impediment (Werner, 2004b). 

14 This agent is in the 2004 edition of the National Fire Protection Association (NFPA) Standard on Clean Agent Fire 

Extinguishing Systems (NFPA, 2004) and has been accepted for future addition to the International Standards 

Organization (ISO) International Standard on Gaseous Fire-Extinguishing Systems (Wickham, 2003a). 
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GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES IV-129

Recovery and Reuse of HFCs 

HFCs can be recovered for reuse at service and decommissioning. For several reasons, however, this 

analysis does not incorporate this option into the cost analysis. First, responsible halon management 

practices are assumed to be a standard convention in fire protection throughout the world.15 Second, 

given the high costs of HFCs, there is a strong financial incentive for maximum recovery following the 

decommissioning of large HFC systems. Most HFC systems—with lifetimes ranging from 10 to 20 

years—have not yet reached the end of their useful lifetimes and, therefore, wide-scale system recovery 

and recycling at decommissioning has not yet occurred; this analysis assumes that such practices will 

occur in the baseline. 

Improved Detection Systems 

One effective way of reducing HFC emissions from the fire-extinguishing sector is to install improved 

detection and control systems to prevent a false discharge (e.g., high-sensitivity smoke detection systems 

that provide early warning to preempt the need for actual system discharge) or minimize the amount of 

agent discharged to extinguish a fire. 

Since advanced detection systems have been available for the last decade or so, this analysis assumes 

that total flooding HFC systems have been and are being equipped with such systems internationally. 

Because improved detection systems are assumed to be used in the baseline, this option is not considered 

in the cost analysis. 

Fine Aerosols 

Aerosols are being developed for use as extinguishing agents in niche markets in the United States, 

such as aerospace, marine, and some military applications. The NFPA has written a draft standard (NFPA 

2010) for this agent (NFPA, 2003). It is possible that if fine aerosols are ever successfully brought to 

market, it may be applicable in other end-uses (Wickham, 2002). 

Because fine aerosols are not currently a viable commercial alternative to HFCs in fire protection, and 

much uncertainty exists as to whether the associated technical and economic barriers will be overcome to 

enable them to become a viable option, fine aerosols are not considered in the cost analysis. 

Inert Gas Generators 

Inert gas generators use a solid material that oxidizes rapidly, producing large quantities of CO2

and/or nitrogen. Although this technology has demonstrated space and weight requirements equivalent 

to halon 1301, it has thus far been used only in specialized applications in the United States (e.g., dry bays 

on military aircraft) (Wickham, 2002). Because of insufficient data on these systems and the uncertainty 

associated with their applicability in other fire-extinguishing applications, this option is not considered in 

the cost analysis. 

 

15 Responsible use practices are currently being developed and endorsed worldwide. For example, the Halon 

Recycling Corporation (HRC) published a Code of Practice for Halon Reclaiming Companies (HRC, n.d.). Because the 

equipment and training needed to reclaim halons are also required to reclaim HFCs, the HRC Code of Practice

establishes the necessary infrastructure and sets the practice of reclamation as the norm for how business is done in 

the fire-protection industry. Although the HRC is a U.S. association, its membership consists of multinational 

corporations operating throughout the world. Similarly, the Halon Alternatives Research Corporation (HARC), the 

USEPA, and other organizations have recently developed and endorsed the Voluntary Code of Practice for the Reduction 

of Emissions of HFC and PFC Fire Protection Agents (VCOP) (Cortina, n.d.). This VCOP will also have international 

reach because HARC members include multinational companies in the alternative agent manufacturing, equipment 

manufacturing, and distribution sectors. 
SECTION IV — INDUSTRIAL PROCESSES • FIRE EXTINGUISHING 

IV-130 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

IV.6.3.2 Summary of Technical Applicability, Market Penetration, and Costs of 

Abatement Options 

Table 6-3 summarizes the technical applicability of each option, which is equal to the estimated global 

average breakout of total fire sector HFC emissions for the application (i.e., total flooding, Class A or B) 

addressed by the option. Technical applicability is used in conjunction with market penetration 

assumptions to develop the emissions reduction potentials for each option, as explained further below. 

Table 6-4 provides the assumptions on maximum market penetration into annual installations of total 

flooding systems designed for the particular application (i.e., Class A or B fires) for each option in 2005, 

2010, 2015, and 2020. Market penetrations were developed separately for Annex I and non-Annex I 

countries to best reflect region-specific qualitative information and possible future action. Table 6-5 

presents the final maximum penetration into the installed base of equipment, taking into account the 

percentage of each applicable fire hazard market that is new (i.e., systems installed in 2005 or later) in all 

preceding years. Values from Table 6-5 are multiplied by technical applicabilities from Table 6-3 to 

generate the percentage reduction off baseline emissions, as presented in Table 6-6. 

Table 6-3: Summary of Technical Applicability of Abatement Options (Percent) 

Annex I and Non-Annex I Countries 

Abatement Option 2005 2010 2015 2020 

Inert gas (Class A flooding) 74.1% 78.9% 85.0% 87.4% 

Water mist (Class B flooding) 3.9% 4.2% 4.5% 4.6% 

FK-5-1-12 (Class A flooding) 74.1% 78.9% 85.0% 87.4% 

Note: Values are expressed as a percentage of total fire-extinguishing emissions. 

To calculate the percentage of emissions reductions off the total fire-extinguishing baseline for each 

abatement option, the technical applicability (from Table 6-3) was multiplied by the market penetration 

values (from Table 6-5), given that the reduction efficiency is 100 percent for each option. For example, to 

determine the percentage reduction off the 2020 baseline for FK-5-1-12 in the United States (or other 

Annex I countries), the following calculation was used: 

 Technical applicability × Incremental maximum market penetration = (6.2) 

87.4% × 23.1% ƿ 20.2% 

Thus, using the assumptions in this analysis, FK-5-1-12 could reduce approximately one fifth of the 

Annex I 2020 emissions baseline. This figure, along with the other projected emissions reductions, is 

shown in Table 6-6. 

Table 6-7 summarizes the cost assumptions used for the fire options presented in the discussions 

above. 
SECTION IV — INDUSTRIAL PROCESSES • FIRE EXTINGUISHING 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES IV-131

Table 6-4: Assumed Incremental Market Penetration of Abatement Options into Newly Installed Class A or 

Class B Extinguishing Systems, Expressed as a Percentage of Emissions from All New 

Equipment 

Abatement Annex I Countries Non-Annex I Countriesa

Option 2005 2010 2015 2020 2005 2010 2015 2020 Considerations/Rationale 

Inert gas 

(New Class A) 

10% 20% 30% 30% 5% 10% 15% 15%  Can displace HFCs in new Class A 

applications 

 Additional space and weight 

requirements 

 Slower discharge times 

 Higher costs compared with baseline 

HFC-227ea systems lead to lower 

market penetration in developing 

countries 

Water mist 

(New Class B)

25% 50% 75% 100% 13% 25% 38% 50%  Can displace HFCs in new Class B 

applications used to protect large 

spaces 

 Technical constraints (assumed to 

be gradually overcome) 

 Higher costs compared with baseline 

HFC-227ea systems lead to lower 

market penetration in developing 

countries 

FK-5-1-12 

(New Class A)

4% 20% 40% 50% 2% 10% 20% 25%  Can displace HFCs in new Class A 

applications 

 No major additional space 

requirements 

 Lowest up-front cost of all 

alternatives considered in this 

analysis 

 Newer player on market compared 

with inert gas and water mist 

systems; will take time to gain 

foothold in market 

 Higher costs compared with baseline 

HFC-227ea systems lead to lower 

market penetration in developing 

countries 

a To account for economic considerations, assumed market penetration values in developing countries are half of those assumed for 

developed countries. 
SECTION IV — INDUSTRIAL PROCESSES • FIRE EXTINGUISHING 

IV-132 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

Table 6-5: Market Penetration of Abatement Options into Newly Installed Class A or Class B Extinguishing 

Systems, Expressed as a Percentage of Total Sector Emissions

Annex I Countries Non-Annex I Countries 

Abatement Option 2005 2010 2015 2020 2005 2010 2015 2020 

Inert gas (Class A) 0.5% 4.5% 11.0% 18.5% 0.3% 2.3% 5.5% 9.3% 

Water mist (Class B) 1.3% 11.3% 27.5% 50.0% 0.7% 5.7% 13.9% 25.2% 

FK-5-1-12 (Class A) 0.2% 3.6% 11.6% 23.1% 0.1% 1.8% 5.8% 11.6% 

Note: Values are expressed as a percentage of technical applicability (i.e., both new and existing Class A or Class B emissions). 

Table 6-6: Percentage of Emissions Reductions Off Total Fire-Extinguishing Baseline 

Abatement Annex I Countries Non-Annex I Countries 

Option 2005 2010 2015 2020 2005 2010 2015 2020 

Inert gas 0.4% 3.6% 9.3% 16.2% 0.2% 1.8% 4.7% 8.1% 

Water mist 0.0% 0.5% 1.2% 2.3% 0.0% 0.2% 0.6% 1.2% 

FK-5-1-12 0.1% 2.8% 9.9% 20.2% 0.1% 1.4% 4.9% 10.1% 

Table 6-7: Summary of Abatement Option Cost Assumptions (2000$) 

Option 

Time Horizon 

(Years) 

U.S. One-Time 

Cost 

U.S. Annual 

Costs 

U.S. Annual 

Savings 

Net U.S. 

Annual Costs 

Inert gases 20 $9.07a $0.18b $0.35c –$0.17 

Water mist 20 $10.89d $0.38b $0.35c $0.03 

FK-5-1-12 20 $7.50e $0.50b $0.35c $0.15 

Note: All costs are per cubic meter of protected space. 

a This one-time cost includes an incremental capital cost and an incremental construction cost (to build additional space). Incremental capital 

costs were assumed to be 10 percent greater in non-Annex I (developing) countries than in the United States and 10 percent less in Japan. 

In all other Annex I countries, capital costs were assumed to be the same as in the United States. No regional adjustments were made to 

incremental construction costs. 

b This cost is associated with additional heating and cooling costs. For all other countries, this annual cost was adjusted by average countryspecific electricity prices (average of 1994–1999) based on Annual Energy Outlook 2000 (Electricity Prices for Industry 1994–1999) (USEIA, 

(2000). 

c Annual savings were assumed to result from avoided HFC-227ea emissions and associated replacement costs. No adjustments were 

assumed for other countries. 

d This one-time cost includes an incremental capital cost and an incremental construction cost (to build additional space). Capital costs were 

assumed to be the same in all other Annex I countries and 10 percent higher in all developing countries. No regional adjustments were made 

to incremental construction costs. 

e This one-time cost includes an incremental capital cost and an incremental construction cost (to build additional space). No regional cost 

adjustments were made. 
SECTION IV — INDUSTRIAL PROCESSES • FIRE EXTINGUISHING 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES IV-133

IV.6.4 Results 

IV.6.4.1 Data Tables and Graphs 

Table 6-8 (2010) and Table 6-9 (2020) provide a summary of the potential emissions reductions at 

various breakeven costs by country/region. The costs to reduce 1 tCO2eq are presented for a 10 percent 

discount rate and 40 percent tax rate. Table 6-10 presents the potential emissions reduction opportunities 

and associated annualized costs for the world in 2020. The results are ordered by increasing costs per 

tCO2eq, using the highest cost in the region under the 10 percent discount rate/40 percent tax rate. 

Because many of the options analyzed affect indirect (CO2 from energy generation for heating/cooling) 

emissions, the net (HFC + CO2) emissions reduced by each option are presented. The direct (HFC) 

emissions reduced by the option and a cumulative total of emissions reduced, in MtCO2eq and 

percentage of the regional fire-extinguishing baseline, are also presented. 

Table 6-8: Country/Regional Emissions Reductions in 2010 and Breakeven Costs for Fire Extinguishing at 

10% Discount Rate, 40% Tax Rate ($/tCO2eq) 

2010 

Country/Region $0 $15 $30 $45 $60 >$60 

Africa 0.00 0.00 0.00 0.00 0.01 0.01 

Annex I 0.00 0.00 0.00 0.22 0.26 0.26 

Australia/New Zealand 0.00 0.00 0.00 0.00 0.00 0.00 

Brazil 0.00 0.00 0.00 0.00 0.00 0.00 

China 0.00 0.00 0.00 0.07 0.07 0.07 

Eastern Europe 0.00 0.00 0.00 0.00 0.00 0.00 

EU-15 0.00 0.00 0.00 0.07 0.08 0.08 

India 0.00 0.00 0.00 0.00 0.00 0.00 

Japan 0.00 0.00 0.00 0.02 0.04 0.04 

Mexico 0.00 0.00 0.00 0.00 0.00 0.00 

Non-OECD Annex I 0.00 0.00 0.00 0.01 0.01 0.01 

OECD 0.00 0.00 0.00 0.23 0.26 0.27 

Russian Federation 0.00 0.00 0.00 0.01 0.01 0.01 

South & SE Asia 0.00 0.00 0.00 0.01 0.01 0.01 

United States 0.00 0.00 0.00 0.11 0.11 0.11 

World Total 0.00 0.00 0.00 0.33 0.37 0.39 

EU-15 = European Union; OECD = Organisation for Economic Co-operation and Development. 
SECTION IV — INDUSTRIAL PROCESSES • FIRE EXTINGUISHING 

IV-134 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

Table 6-9: Country/Regional Emissions Reductions in 2020 and Breakeven Costs for Fire Extinguishing at 

10% Discount Rate, 40% Tax Rate ($/tCO2eq) 

2020 

Country/Region $0 $15 $30 $45 $60 >$60 

Africa 0.00 0.00 0.00 0.06 0.11 0.12 

Annex I 0.00 0.00 0.00 1.97 2.19 2.25 

Australia/New Zealand 0.00 0.00 0.00 0.04 0.04 0.04 

Brazil 0.00 0.00 0.00 0.00 0.00 0.00 

China 0.00 0.00 0.00 0.88 0.88 0.94 

Eastern Europe 0.00 0.00 0.00 0.04 0.04 0.04 

EU-15 0.00 0.00 0.00 0.79 0.81 0.84 

India 0.00 0.00 0.00 0.01 0.02 0.02 

Japan 0.00 0.00 0.00 0.19 0.34 0.36 

Mexico 0.00 0.00 0.00 0.01 0.01 0.01 

Non-OECD Annex I 0.00 0.00 0.00 0.12 0.13 0.13 

OECD 0.00 0.00 0.00 2.00 2.22 2.29 

Russian Federation 0.00 0.00 0.00 0.11 0.12 0.12 

South & SE Asia 0.00 0.00 0.00 0.10 0.10 0.11 

United States 0.00 0.00 0.00 0.70 0.74 0.74 

World Total 0.00 0.00 0.00 3.30 3.62 3.77 

EU-15 = European Union; OECD = Organisation for Economic Co-operation and Development. 

Table 6-10: World Breakeven Costs and Emissions Reductions in 2020 for Fire Extinguishing 

Cost (2000$/tCO2eq) 

DR = 10%, TR=40% Reduction 

Option Low High 

Direct 

Emissions 

Reductiona

(MtCO2eq) 

Indirect 

Emissions 

Impactb

(MtCO2eq) 

% 

Reduction 

from 2020 

Baseline 

Running 

Sum of 

Reductions 

(MtCO2eq) 

Cum. % 

Reduction 

from 2020 

Baseline 

FK-5-1-12 $37.26 $37.58 1.97 0.00 14.4% 1.97 14.4% 

Inert gases $34.53 $48.85 1.58 -0.11 11.5% 3.55 25.9% 

Water mist $48.16 $82.40 0.23 -0.04 1.6% 3.77 27.6% 

a Direct reductions refer to HFC emissions reductions (off the baseline). 

b Indirect emissions impacts are those associated with energy consumption (not included in the baseline). 
SECTION IV — INDUSTRIAL PROCESSES • FIRE EXTINGUISHING 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES IV-135

Figures 6-2 (2010) and 6-3 (2020) present MACs for this sector at 10 percent discount rates and 40 

percent tax rates. 

Figure 6-2: 2010 MAC for Fire Extinguishing, 10% Discount Rate, 40% Tax Rate 

EU-15 = European Union; OECD = Organisation for Economic Co-operation and Development. 

Figure 6-3: 2020 MAC for Fire Extinguishing, 10% Discount Rate, 40% Tax Rate 

EU-15 = European Union; OECD = Organisation for Economic Co-operation and Development. 
SECTION IV — INDUSTRIAL PROCESSES • FIRE EXTINGUISHING 

IV-136 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

IV.6.4.2 Uncertainties and Limitations 

This section focuses on the uncertainties and limitations associated with the cost estimates presented 

in this analysis. One area of uncertainty is in how capital costs for these mitigation technologies may vary 

internationally, given that estimates were available only for several countries, and only for two of the 

three options assessed (water mist and inert gas). The analysis of the FK-5-1-12 option is currently limited 

in the lack of this specificity on region-specific cost analysis estimates. In addition, it should be noted that 

the global implementation of each option through 2020 is based on information currently available and 

expert opinion. Great uncertainty is associated with future projections of market behavior. 

IV.6.5 Summary 

Baseline HFC emissions from fire extinguishing are estimated to grow between 2005 and 2020, with 

the highest emissions growth expected to occur in non-Annex I countries. It is estimated that the vast 

majority of these emissions will come from total flooding applications; only a minor amount will come 

from streaming applications. Several alternatives to ozone-depleting halon 1301 for total flooding 

applications exist, including gaseous alternatives such as HFCs, carbon dioxide, inert gases, and 

fluorinated ketones, as well as NIK alternatives such as dispersed and condensed aerosol systems, water 

sprinklers, water mist, foam, and inert gas generators. 

This analysis reviewed these alternatives and analyzed in detail three mitigation options for total 

flooding fire-extinguishing applications: substituting HFC systems used in new systems designed to 

protect against Class A fire hazards with inert gas systems, substituting HFCs used in new systems 

designed to protect against Class B fire hazards with water mist systems, and substituting HFC systems 

used in new systems designed to protect against Class A fire hazards with FK-5-1-12 systems. Inert gas 

and FK-5-1-12 systems may offer good opportunities to reduce emissions in total flooding applications 

globally. Water mist systems also have the potential to reduce global emissions from this sector, but to a 

lesser extent, because they are applicable only to Class B fire hazards. 

This analysis demonstrates that there is a portfolio of alternatives to HFCs in the total flooding sector 

that can be employed to reduce HFC use and associated emissions. These alternatives include FK-5-1-12, 

inert gases, water mist, and other agents and systems discussed qualitatively in this report. The global 

implementation of each option through 2020 is based on a “best-guess” scenario. With more data, these 

forecasts can be improved. 

IV.6.6 References 

Cortina, TA. No date. Voluntary Code of Practice for HFC and PFC Fire Protection Agents. Available at 

<http://www.bfrl.nist.gov/866/HOTWC/HOTWC2002/pubs/11_Cortina.pdf>. Accessed on June 14, 

2006. 

Europa. 2003. Regulation (EC) No. 2037/2000 of the European Parliament and of the Council of 29 June 

2000 on substances that deplete the ozone layer. Europa. Available at <http://europa.eu.int/eurlex/pri/en/oj/dat/2000/l_244/l_24420000929en00010024.pdf>. Accessed on October 13, 2003. 

Halon Recycling Corporation. No date. Code of Practice for Halon Reclaiming Companies. Available at 

http://www.halon.org/pdfs/code.pdf>. Accessed on June 14, 2006.

ICF Consulting. September 10, 2003. Re-evaluation of a C-6 Oxyfluorocarbon (trade name Novec 1230) and 

References. Memorandum delivered by ICF Consulting to Erin Birgfeld under USEPA Contract 

Number 68-D-00-266, Work Assignment 2-05 Task 03. 
SECTION IV — INDUSTRIAL PROCESSES • FIRE EXTINGUISHING 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES IV-137

Intergovernmental Panel on Climate Change (IPCC). 1996. Climate Change 1995: The Science of Climate 

Change. J.T. Houghton, L.G. Meira Filho, B.A. Callander, N. Harris, A. Kattenberg, and K. Maskell 

(eds.). Cambridge, UK: Cambridge University Press. 

Intergovernmental Panel on Climate Change/Technology and Economic Assessment Panel (IPCC/TEAP). 

July 1999. Meeting Report of the Joint IPCC/TEAP Expert Meeting on Options for the Limitation of Emissions 

of HFCs and PFCs. Report jointly sponsored by the IPCC Working Group III and the TEAP of the 

Montreal Protocol (ECN-RX--99-029). Available at <http://www.ecn.nl/docs/library/report/1999/ 

rx99029.pdf>. Accessed on November 20, 2003. 

International Maritime Organization (IMO). November 30, 2001. Performance Testing and Approval 

Standards for Fire Safety Systems: Fire Test Protocols for Fire-Extinguishing Systems. Submitted by 

Germany to the International Maritime Organization Subcommittee on Fire-Protection, 46th session, 

Agenda item 12. 

International Maritime Organization (IMO). October 10, 2003. Performance Testing and Approval Standards 

for Fire Safety Systems—Report of the Correspondence Group. Submitted by the United States to the 

International Maritime Organization Subcommittee on Fire Protection, 48th session, Agenda item 5. 

Kucnerowicz-Polak, B. March 28, 2002. “Halon Sector Update.” Presented at the 19th Meeting of the 

Ozone Operations Resource Group (OORG), The World Bank, in Washington, DC. 

March Consulting Group. September 1998. Opportunities to Minimize Emissions of Hydrofluorocarbons 

(HFCs) from the European Union: Final Report. 

March Consulting Group. January 1999. UK Emissions of HFCs, PFCs, and SF6 and Potential Emissions 

Reduction Options: Final Report. 

National Fire Protection Association (NFPA). 2000. NFPA 12: Standard on Carbon Dioxide Extinguishing 

Systems, 2000 Edition. National Fire Protection Association. 

National Fire Protection Association (NFPA). July 21, 2003. Proposed Draft of NFPA 2010: Standard for Fixed 

Aerosol Fire Extinguishing Systems, 2005 Edition. Available at <http://www.nfpa.org/PDF/ 

2010_Draft0903.pdf?src=nfpa>. Accessed on October 24, 2003. 

National Fire Protection Association (NFPA). 2004. NFPA 2001: Standard on Clean Agent Fire Extinguishing 

Systems. 

United Nations Environment Programme (UNEP). October 1999. Production and Consumption of Ozone 

Depleting Substances 1986-1998. 

United Nations Environment Programme (UNEP). 2001. Standards and Codes of Practice to Eliminate 

Dependency on Halons: Handbook of Good Practices in the Halon Sector. United Nations Publication ISBN 

92-807-1988-1., UNEP Division of Technology, Industry and Economics (DTE) under the OzonAction 

Programme under the Multilateral Fund for the Implementation of the Montreal Protocol, in 

cooperation with The Fire Protection Research Foundation. 

U.S. Energy Information Administration (USEIA). 2000. Annual Energy Outlook 2000 (Electricity Prices for 

Industry 1994-1999). Available at <http://www.eia.doe.gov/emeu/international/elecprii.html>. 

Accessed on April 2, 2002. 

U.S. Environmental Protection Agency (USEPA). 1994. SNAP Technical Background Document: Risk Screen 

on the Use of Substitutes for Class I Ozone-Depleting Substances: Fire Suppression and Explosion Protection 

(Halon Substitutes). Washington, DC: U.S. Environmental Protection Agency. 

U.S. Environmental Protection Agency (USEPA). February 2000. Carbon Dioxide as a Fire Suppressant: 

Examining the Risks. EPA 430-R-00-002. Washington, DC: U.S. Environmental Protection Agency, 

Office of Air and Radiation. 

U.S. Environmental Protection Agency (USEPA). April 2004. Inventory of U.S. Greenhouse Gas Emissions 

and Sinks: 1990-2002. EPA 430-R-04-003. Washington, DC: U.S. Environmental Protection Agency, 

Office of Atmospheric Programs. 

Verdonik, Daniel P. and Mark L. Robin. 2004. Analysis of Emissions Data, Estimates, and Modeling of 

Fire Protection Agents. Conference proceedings from the 15th Annual Earth Technologies Forum and 

Mobile Air Conditioning Summit in Washington, DC. April 13-15. 
SECTION IV — INDUSTRIAL PROCESSES • FIRE EXTINGUISHING 

IV-138 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

Werner, Kurt. 2004a. Expert review comments on the Draft Analysis of International Costs to Abate HFC PFC 

Emissions from Fire Extinguishing. Comments received via email on January 26. 

Werner, Kurt. 2004b. Expert review comments on the Draft Analysis of International Costs to Abate HFC PFC 

Emissions from Fire Extinguishing. Comments received via e-mail May 20–21. 

Wickham, Robert. 2002. Status of Industry Efforts to Replace Halon Fire Extinguishing Agents. Wickham 

Associates. March 16. Available at <http://www.epa.gov/ozone/snap/fire/status.pdf>. 

Wickham, Robert. 2003a. Expert review comments on the Draft Analysis of International Costs to Abate HFC 

PFC Emissions from Fire Extinguishing. Comments received in writing and by phone in October. 

Wickham, Robert. 2003b. Review of the Use of Carbon Dioxide Total Flooding Fire Extinguishing Systems. 

Wickham Associates, August 8. Available at <http://www.epa.gov/ozone/snap/fire/co2/ 

co2report2.pdf>. 
SECTION IV — INDUSTRIAL PROCESSES • ALUMINUM PRODUCTION 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES IV-139

IV.7 PFC Emissions from Aluminum Production 

he primary aluminum production industry is currently the largest source of PFC emissions 

globally. During the aluminum smelting process, when the alumina ore content of the 

electrolytic bath falls below critical levels required for electrolysis, rapid voltage increases 

occur. These are termed “anode effects” (AEs). Anode effects produce CF4 and C2F6 emissions when 

carbon from the anode and fluorine from the dissociated molten cryolite bath combine. In general, the 

magnitude of emissions for a given level of production depends on the frequency and duration of these 

anode effects; the more frequent and long-lasting the anode effects, the greater the emissions. This report 

presents two baselines for PFC emissions from primary aluminum production: the technology-adoption 

baseline and the no-action baseline (Tables 7-1 and 7-2). 

IV.7.1 Technology-Adoption Baseline 

Under the technology-adoption baseline scenario, it is assumed that aluminum producers will 

continue to introduce technologies and practices aimed at reducing PFC emissions. It is assumed that 

under the technology-adoption scenario, global aluminum producers, in accordance with International 

Aluminum Institute (IAI) PFC emissions reduction commitments, will reduce their PFC emissions 

intensity (i.e., PFC emissions per ton of produced aluminum) by 80 percent from 1990 levels by 2010. This 

reduction can be achieved by retrofitting smelters with emissions-reducing technologies such as 

computer control systems and point feeding systems, by shifting production to Point-Feed Prebake 

(PFPB) technology, and by adopting management and work practices aimed at reducing PFC emissions. 

Five different electrolytic cell types are used to produce aluminum: Vertical Stud Soderberg (VSS), 

Horizontal Stud Soderberg (HSS), Side-Worked Prebake (SWPB), Center-Worked Prebake (CWPB), and 

PFPB, which is considered the most technologically advanced process to produce aluminum. Although 

PFPB systems can be improved through the implementation of management and work practices, as well 

as improved control software, the analysis assumes that retrofit abatement options will occur only on 

existing VSS, HSS, SWPB, and CWPB cells. 

Figure 7-1 presents total PFC emissions from aluminum production under the technology-adoption 

baseline scenario from 1990 through 2020. Between 1990 and 1995, global emissions declined from 98 to 

61 MtCO2eq. This significant decline was the result of voluntary measures undertaken by global smelters 

to reduce their AE minutes per cell day. These measures included incremental improvements in smelter 

technologies and practices, and a shift in the share of SWPB-related production to more state-of-the-art 

PFPB facilities. Although a continuation of this AE minute reduction trend occurred through 2000, 

emissions reductions were offset by a 24 percent increase in global aluminum production between 1995 

and 2000. 

The declining global emissions levels through 2010 reflect the successful adoption of IAI emissions 

reduction goals through both retrofits and a continued shift of production from VSS, HSS, and SWPB to 

PFPB. From 2010 through 2020, the emissions intensity is assumed to remain constant; consequently, 

emissions will be driven by increasing aluminum production. PFC emissions in OECD, as well as non-EU 

Eastern Europe, non-EU FSU, China/CPA, and S&E Asia are projected to remain relatively constant from 

2010 through 2020, due to slowing aluminum production growth. Trends in the United States and the 

EU-25 reflect overall trends in the developed (OECD) countries. Africa, Latin America, and the Middle 

East are projected to increase their share of global emissions from 2010 through 2020, due to strong 

T 
SECTION IV — INDUSTRIAL PROCESSES • ALUMINUM PRODUCTION 

IV-140 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

Table 7-1: Total PFC Emissions from Aluminum Manufacturing (MtCO2eq)—No-Action Baseline 

Country/Region 2000 2010 2020 

Africa 5.6 6.0 8.6 

Annex I 37.3 37.8 38.3 

Australia/New Zealand 3.5 2.8 2.8 

Brazil 3.9 3.5 4.7 

China 5.2 13.2 13.5 

Eastern Europe 2.9 1.2 1.2 

EU-15 8.1 4.7 4.7 

India 0.8 2.2 2.4 

Japan 0.0 0.2 0.2 

Mexico 0.1 0.1 0.1 

Non-OECD Annex I 9.2 8.3 8.2 

OECD 28.1 29.6 30.2 

Russian Federation 7.5 7.4 7.3 

South & SE Asia 0.2 0.8 0.8 

United States 9.0 14.7 14.7 

World Total 57.8 69.8 77.1 

EU-15 = European Union; OECD = Organisation for Economic Co-operation and Development 

Table 7-2: Total PFC Emissions from Aluminum Manufacturing (MtCO2eq)—Technology-Adoption Baseline 

Country/Region 2000 2010 2020 

Africa 5.6 4.0 5.7 

Annex I 37.4 18.9 19.6 

Australia/New Zealand 3.5 2.5 2.5 

Brazil 3.9 2.4 3.2 

China 5.2 6.5 6.7 

Eastern Europe 2.9 0.8 0.8 

EU-15 8.1 3.5 3.5 

India 0.8 1.2 1.3 

Japan 0.0 0.1 0.1 

Mexico 0.1 0.1 0.1 

Non-OECD Annex I 9.3 3.9 3.9 

OECD 28.2 15.0 15.8 

Russian Federation 7.5 3.3 3.3 

South & SE Asia 0.2 0.6 0.7 

United States 9.0 4.6 4.4 

World Total 58.0 39.1 44.7 

EU-15 = European Union; OECD = Organisation for Economic Co-operation and Development 
SECTION IV — INDUSTRIAL PROCESSES • ALUMINUM PRODUCTION 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES IV-141

Figure 7-1: PFC Emissions from Aluminum Production Based on a Technology-Adoption Scenario—

1990−2020 (MtCO2eq) 

CPA = Centrally Planned Asia; EU-25 = European Union; Non-EU FSU = non-European Union Former Soviet Union countries; OECD90+ = 

Organisation of Economic Co-operation and Development; S&E Asia = Southeast Asia. 

growth in aluminum production. In 2020, China/CPA, Latin America, Africa, and the Middle East are 

expected to collectively account for 50 percent of global emissions. In comparison, OECD is projected to 

account for 36 percent of global emissions, down from 51 percent in 2000. 

IV.7.2 No-Action Baseline 

Under the no-action baseline scenario, it is assumed that aluminum producers will take no retrofit 

actions to reduce their emissions below the levels of the late 1990s; as a result, emissions projections do 

not reflect anticipated technology adoptions and/or the implementation of improved work and 

management practices to reduce emissions. Figure 7-2 presents total PFC emissions from aluminum 

production under the no-action baseline scenario from 1990 through 2020. The trends from 1990 through 

2000 are the same as those in the technology-adoption baseline. From 2000 through 2020, no additional 

abatement retrofits are assumed to occur; however, as in the technology-adoption baseline, it is assumed 

that the global historical trend in the shift of production from SWPB to PFPB continues (IAI, 2000, 2005b). 

Based on these assumptions, global emissions under this scenario rise to 77 MtCO2eq in 2020, a 33 percent 

increase over 2000 levels. This is primarily driven by increasing global aluminum production. 

In 1990, OECD emissions accounted for approximately 60 percent of global emissions; however, by 

2020, this share is reduced to 40 percent in this scenario. This reduction is the result of relatively flat 

aluminum production levels between 2000 and 2020, as cheaper aluminum from developing countries 

enters the global marketplace. The primary sources of this cheaper aluminum are China/CPA, the Middle 

East, Latin America, and Africa, which in 2020 are projected to have production levels approximately 
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IV-142 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

Figure 7-2: PFC Emissions from Aluminum Production Based on a No-Action Scenario—1990–2020 

(MtCO2eq) 

CPA = Centrally Planned Asia; EU-25 = European Union; Non-EU FSU = non-European Union Former Soviet Union countries; OECD90+ = 

Organisation of Economic Co-operation and Development; S&E Asia = Southeast Asia. 

200 percent greater than their 2000 levels. In 2020, China/CPA is projected to account for 17.5 percent of 

global emissions, compared with 3 percent in 1990 and 9 percent in 2000. 

The EU-25 and the United States reflect the general OECD trend, except that between 2000 and 2005 

there is an increase in U.S. emissions and a decrease in EU emissions. The decrease in EU emissions is 

primarily the result of their transition from SWPB to PFPB technology. The increase in U.S. emissions is 

an artifact of the baseline calculation methodology. Past U.S. emissions reflect reductions already 

implemented by members of the USEPA’s Voluntary Aluminum Industrial Partnership, but under this 

scenario, future U.S. emissions (from 2005 forward) are projected to occur at a higher rate. 

IV.7.3 Cost of PFC Emissions Reduction from Aluminum Production 

IV.7.3.1 Abatement Options 

The most direct and cost-efficient method to reduce PFC emissions and improve process efficiency is 

to retrofit existing aluminum production technology. Two types of retrofit options can be implemented: 

(1) installation or refinement of process computer control systems, and (2) the installation or conversion 

to alumina point-feed systems. The installation of process computer controls can be considered a minor 

retrofit, whereas the installation of alumina point-feed systems can be considered a major retrofit. These 

two reduction technologies are not mutually exclusive, but additive. In fact, point-feed systems require 

computer controls in order to be effective, although the reverse is not true. 

In this analysis, these two options are assumed to be adopted in succession. At relatively low carbon 

prices, computer controls are adopted by 100 percent of the market (i.e., 100 percent of a given cell 

technology) and at higher carbon prices, alumina point feed systems are adopted by 100 percent of the 
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GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES IV-143

market. The costs and reductions of installing alumina point-feed systems are additive to those of 

installing computer controls. (Of course, if carbon prices are high enough at the outset, the two options 

will not be adopted successively in time, but simultaneously. In any event, the MACs provide an accurate 

measure of the potential reductions at all carbon prices.) 

Cost and Reduction Assumptions 

Cost assumptions for each mitigation option are based on information reported in Greenhouse Gas 

Emissions from the Aluminum Industry (IEA, 2000). The remainder of Section IV.7.2.1 will provide an 

overview of each abatement option and detail the cost assumptions used. 

Table 7-3 provides a summary of the potential reduction opportunities associated with each 

mitigation option. The reduction efficiencies of complete retrofits (i.e., retrofits including installation of 

both computer controls and point-feed systems) were estimated by assuming that after implementation of 

the complete retrofit, the cell will operate (and emit PFCs) as a PFPB cell. Consequently, the reduction 

efficiencies were based on the differences between the PFC emissions rates (tCO2eq/t Al) of unabated 

VSS, HSS, SWPB, and CWPB cells and the PFC emissions rate of PFPB cells. The emissions rates of 

unabated VSS, HSS, SWPB, and CWPB cells were represented by the average global 1995 emissions rates 

of those technologies, because the market penetration of minor and major retrofits was believed to be 

small in 1995. The complete retrofit reduction efficiencies range from 41 to 93 percent, depending on cell 

type. 

Table 7-3: Reduction Efficiency Potential for Abatement Option by Cell Type (Percent) 

Cell Technology Type 

Abatement Option VSS HSS SWPB CWPB 

Computer controls (minor retrofit ) 35.5% 33.5% 23% 31% 

Point-feed (major retrofit ) 35.5% 33.5% 70% 10% 

Complete retrofit (both) 71.0% 77.0% 93% 41% 

The distribution of maximum reduction efficiencies (i.e., those associated with complete retrofits) 

between minor and major retrofits was estimated based on communications with industry (Marks, 2006). 

For VSS and HSS, it was assumed that reductions are evenly split (i.e., minor and major retrofits each 

achieve 50 percent of the reductions of a complete retrofit). For SWPB, 25 percent of the total reduction 

was assumed to result through implementation of the minor retrofit, with the remainder occurring 

through the major retrofit. For CWPB, 75 percent of the total reduction was assumed to occur through 

implementation of the minor retrofit, whereas 25 percent was assumed to occur through implementation 

of the major retrofit. 

Although PFPB systems can be further improved through the implementation of control software 

(Marks, 2006), this analysis assumes that retrofit abatement options will occur only on existing VSS, HSS, 

SWPB, and CWPB technologies. 

Because the PFC abatement options are based on the retrofitting of existing cell technologies and not 

on a major change in technology, the maximum market penetration available is assumed to be 100 

percent of emissions from the VSS, HSS, SWPB, and CWPB cell type production lines. However, the 

applicability of cell type–specific retrofit options to baseline emissions is dependent on the country-level 

distribution of cell technologies. 
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IV-144 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

Installation/Refinement of Computer Controls (Minor Retrofit)

The minor retrofit option includes the installation of process computer control systems or the 

refinement of existing process control algorithms. Computer systems provide greater control over 

alumina feeding, enable control of the repositioning of the anodes as they are consumed during 

aluminum production, and enhance the ability to predict and suppress AEs. Consequently, computer 

systems have the potential to increase productivity, lower energy costs, and reduce PFC emissions. The 

minor retrofit option is assumed to have the potential to reduce PFC emissions factors (tCO2eq/t Al) by 

between 23 percent and 36 percent, depending on the cell type (see Table 7-4). 

Cost and Emissions Reduction Analysis 

• Capital/Upfront Costs. For a typical facility that produces 200,000 tonnes of aluminum, capital 

costs are assumed to range from $4.2 to $5.1 million, depending on the cell type (IEA, 2000). 

• Annual Costs. Implementation of the minor retrofit option is assumed to produce an incremental 

increase in operating costs between 2 and 3 percent per year depending on the cell technology 

type. Operating costs are assumed to include costs associated with operation and maintenance 

labor and with overhead and administrative costs. Country-specific operating costs are 

determined by applying the incremental operating cost associated with this option to the regional 

baseline operating costs developed for IEA (2000). 

• Cost Savings. The reduction in AE minutes per cell day produced by the mitigation option is 

assumed to result in a corresponding increase in aluminum production. This analysis assumes 

that the cost of aluminum is $1,400 per metric ton. Additional cost savings from reduced 

aluminum fluoride losses and energy consumption were estimated using assumptions detailed in 

Estimating the Cost of an Anode Effect (USEPA, 2002). 

Installation of Point-Feed Systems (Major Retrofit)

The major retrofit option includes only the installation of alumina point-feed systems. This option is 

considered to take place in addition to the implementation of the minor retrofit. The benefits and costs 

associated with the minor retrofit option are considered fully implemented and therefore are not 

included in the analysis of this option. The implementation of this option results in improved cell 

performance and increased PFC emissions reductions. 

The alumina point-feed system allows alumina to be fed at shorter time intervals and at different 

positions along the bath, compared with feeding techniques used by existing VSS, HSS, SWPB, and 

CWPB cells. PFC emissions occur as alumina levels in the cell bath decline, typically below 2 percent by 

weight of cell bath composition (Dugois, 1994), and the remaining fluorine-containing bath components 

begin to undergo electrolysis. Since AEs can be terminated through the addition of more alumina, point 

feeding will ensure that alumina is fed continuously into the central parts of the cell, where the bath area 

is largest. Furthermore, point feeding also increases the cell current efficiency and consequently reduces 

the cell electricity consumption. The major retrofit option is assumed to have the potential to reduce PFC 

emissions factors by between 10 and 70 percent, depending on the technology type (see Table 7-4). 

Cost and Emissions Reduction Analysis 

• Capital/Upfront Costs. Capital costs for VSS and HSS cells are assumed to be approximately $39 

million (IEA, 2000), whereas those for SWPB cells are assumed to be approximately $82 million 

(Marks, 2006). For CWPB cells, capital costs are approximately $3.5 million (IEA, 2000). 

• Annual Costs. Implementation of the major retrofit option is assumed to produce an incremental 

increase in operating costs between 1 and 3 percent per year, depending on the cell technology 
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GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES IV-145

type. Operating costs are assumed to include costs associated with operation and maintenance 

labor and with overhead and administrative costs (IEA, 2000). 

• Cost Savings. Similar to the minor retrofit option, cost savings include benefits associated with 

avoided aluminum production losses, reduced electricity consumption, and reduced aluminum 

fluoride losses. For this analysis, it is assumed that the cost of aluminum is $1,400 per metric ton. 

Assumptions used to estimate benefits associated with reduced energy consumption and fluoride 

losses are detailed in Estimating the Cost of an Anode Effect (USEPA, 2002). 

Industry experts indicate that if the computer control system is installed separately from the pointfeed system, particularly if it is installed several years earlier, the computer control system is likely to 

require an update in its software to accommodate the point-feed system. The costs of such an update are 

not included in this analysis. However, the USEPA believes that these costs are likely to be small relative 

to the costs of the point-feed system itself. 

Baseline Market Penetration of Options in No-Action and Technology-Adoption Baselines

The reductions achieved by each technology in each scenario are based not only on the reduction 

efficiency and maximum market penetration of that technology but also on the share of the market that is 

already claimed by the technology in the baseline of concern. For example, if a technology had already 

achieved a 100 percent market penetration in the baseline of concern, no reductions from that technology 

would be available in the MAC associated with that baseline. 

In both the no-action and technology-adoption scenarios, there is some baseline market penetration 

by the minor and major retrofit options. In the no-action scenario, plant operators outside of the United 

States are assumed to have adopted complete retrofits to the extent required to achieve the 2000 

emissions factor for each technology, which is significantly lower than the 1995 emissions factor.1

 In the 

technology-adoption scenario, plant operators are assumed to have adopted complete retrofits to the 

extent required to achieve the 2010 IAI goal of reducing emissions intensities by 80 percent relative to the 

1990 level. Table 7-4 shows the global average baseline market penetrations of complete retrofits in both 

scenarios. 

Table 7-4: Averagea Baseline Market Penetration of Complete Retrofits by Cell Type and Scenario (Percent) 

Cell Technology Type 

Scenario VSS HSS SWPB CWPB 

No-action 30% 21% 16% 52% 

Technology-adoption 98% 75% 24% 94% 

a These are global averages. Individual countries may have slightly larger or slightly smaller baseline market penetrations. 

For the United States, the baseline market penetration of retrofits in the no-action scenario is assumed 

to be zero. This is because the U.S. no-action baseline emissions are based on a 1990 emissions factor, and 

few if any retrofits are believed to have been performed by 1990. 

The assumption that complete retrofits were adopted in all cases is a simplification; in fact, it is likely 

that some plant operators have adopted only minor retrofits. If this were explicitly modeled in the 

analysis, the baseline market penetration of minor retrofits would grow, while that of major retrofits 

 

1 Although the various types of cells (VSS, SWPB, etc.) become PFPB cells after implementation of a complete retrofit, 

the IEA model, which was used as the basis for this analysis, continues to track converted cells under their old cell 

technologies. Thus, it is reasonable to treat retrofits this way in this context. 
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IV-146 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

would decline. Thus, this analysis may overestimate the reductions available from minor retrofits and 

underestimate those available from major retrofits. 

IV.7.4 Results 

This section discusses the results from the MAC analysis for the world and for various regions for the 

no-action and technology-adoption scenarios. 

IV.7.4.1 Data Tables and Graphs 

Tables 7-5 through 7-10 provide a summary of the potential emissions reduction opportunities and 

associated costs for various regions in 2010 and 2020 under the no-action and technology-adoption 

scenarios. The costs to reduce 1 tCO2eq are presented at a 10 percent discount rate and 40 percent tax rate. 

Table 7-5: Emissions Reductions in 2010 and Breakeven Costs ($/tCO2eq) for Aluminum Production at 10% 

Discount Rate, 40% Tax Rate (MtCO2eq)—No-Action Baseline 

2010 

Country/Region $0 $15 $30 $45 $60 >$60 

Africa 1.17 2.56 3.23 3.23 3.23 3.23 

Annex I 3.88 12.28 17.45 17.45 17.45 17.45 

Australia/New Zealand 0.31 0.44 0.44 0.44 0.44 0.44 

Brazil 0.29 1.49 1.91 1.91 1.91 1.91 

China 2.84 3.48 6.78 6.78 6.78 6.78 

Eastern Europe 0.22 0.48 0.62 0.62 0.62 0.62 

EU-15 0.00 1.60 1.90 1.90 1.90 1.90 

India 0.45 0.65 1.13 1.13 1.13 1.13 

Japan 0.00 0.05 0.11 0.11 0.11 0.11 

Mexico 0.00 0.00 0.00 0.00 0.00 0.00 

Non-OECD Annex I 1.91 2.79 5.22 5.22 5.22 5.22 

OECD 1.97 9.49 12.23 12.23 12.23 12.23 

Russian Federation 1.83 2.42 4.68 4.68 4.68 4.68 

South & SE Asia 0.14 0.18 0.18 0.18 0.18 0.18 

United States 1.14 6.18 7.48 7.48 7.48 7.48 

World Total 9.50 21.77 31.90 31.90 31.90 31.90 

EU-15 = European Union; OECD = Organisation for Economic Co-operation and Development 
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GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES IV-147

Table 7-6: Emissions Reductions in 2020 and Breakeven Costs ($/tCO2eq) for Aluminum Production at 10% 

Discount Rate, 40% Tax Rate (MtCO2eq)—No-Action Baseline 

2020 

Country/Region $0 $15 $30 $45 $60 >$60 

Africa 1.72 3.64 4.65 4.65 4.65 4.65 

Annex I 3.87 12.47 17.80 17.80 17.80 17.80 

Australia/New Zealand 0.31 0.44 0.44 0.44 0.44 0.44 

Brazil 0.36 1.97 2.62 2.62 2.62 2.62 

China 2.74 3.60 6.99 6.99 6.99 6.99 

Eastern Europe 0.22 0.48 0.61 0.61 0.61 0.61 

EU-15 0.00 1.62 1.94 1.94 1.94 1.94 

India 0.45 0.70 1.22 1.22 1.22 1.22 

Japan 0.00 0.07 0.15 0.15 0.15 0.15 

Mexico 0.00 0.00 0.00 0.00 0.00 0.00 

Non-OECD Annex I 1.85 2.77 5.17 5.17 5.17 5.17 

OECD 2.02 9.70 12.63 12.63 12.63 12.63 

Russian Federation 1.77 2.38 4.61 4.61 4.61 4.61 

South & SE Asia 0.15 0.19 0.19 0.19 0.19 0.19 

United States 1.14 6.18 7.48 7.48 7.48 7.48 

World Total 10.16 23.86 34.86 34.86 34.86 34.86 

EU-15 = European Union; OECD = Organisation for Economic Co-operation and Development 

Table 7-7: Emissions Reductions in 2010 and Breakeven Costs ($/tCO2eq) for Aluminum Production at 10% 

Discount Rate, 40% Tax Rate (MtCO2eq)—Technology-Adoption Baseline 

2010 

Country/Region $0 $15 $30 $45 $60 >$60 

Africa 0.35 1.40 1.40 1.40 1.40 1.40 

Annex I 0.40 2.40 2.93 2.93 2.93 2.93 

Australia/New Zealand 0.06 0.15 0.15 0.15 0.15 0.15 

Brazil 0.19 0.81 0.86 0.86 0.86 0.86 

China 0.02 0.22 0.41 0.41 0.41 0.41 

Eastern Europe 0.07 0.27 0.28 0.28 0.28 0.28 

EU-15 0.00 0.87 0.87 0.87 0.87 0.87 

India 0.01 0.07 0.12 0.12 0.12 0.12 

Japan 0.00 0.02 0.04 0.04 0.04 0.04 

Mexico 0.00 0.00 0.00 0.00 0.00 0.00 

Non-OECD Annex I 0.16 0.56 0.85 0.85 0.85 0.85 

OECD 0.24 1.84 2.08 2.08 2.08 2.08 

Russian Federation 0.12 0.36 0.60 0.60 0.60 0.60 

South & SE Asia 0.02 0.02 0.02 0.02 0.02 0.02 

United States 0.18 0.64 0.81 0.81 0.81 0.81 

World Total 1.14 5.31 6.13 6.13 6.13 6.13 

EU-15 = European Union; OECD = Organisation for Economic Co-operation and Development 
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IV-148 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

Table 7-8: Emissions Reductions in 2020 and Breakeven Costs ($/tCO2eq) for Aluminum Production at 10% 

Discount Rate, 40% Tax Rate (MtCO2eq)—Technology-Adoption Baseline 

2020 

Country/Region $0 $15 $30 $45 $60 >$60 

Africa 0.49 1.95 1.95 1.95 1.95 1.95 

Annex I 0.40 2.47 3.06 3.06 3.06 3.06 

Australia/New Zealand 0.06 0.15 0.15 0.15 0.15 0.15 

Brazil 0.24 1.03 1.10 1.10 1.10 1.10 

China 0.02 0.28 0.54 0.54 0.54 0.54 

Eastern Europe 0.07 0.27 0.27 0.27 0.27 0.27 

EU-15 0.00 0.87 0.87 0.87 0.87 0.87 

India 0.02 0.09 0.15 0.15 0.15 0.15 

Japan 0.00 0.02 0.05 0.05 0.05 0.05 

Mexico 0.00 0.00 0.00 0.00 0.00 0.00 

Non-OECD Annex I 0.15 0.57 0.87 0.87 0.87 0.87 

OECD 0.24 1.90 2.20 2.20 2.20 2.20 

Russian Federation 0.11 0.37 0.61 0.61 0.61 0.61 

South & SE Asia 0.02 0.02 0.02 0.02 0.02 0.02 

United States 0.18 0.65 0.81 0.81 0.81 0.81 

World Total 1.34 6.24 7.24 7.24 7.24 7.24 

EU-15 = European Union; OECD = Organisation for Economic Co-operation and Development 

Table 7-9: Emissions Reduction and Costs in 2020—No-Action Baseline 

Cost 

(2000$/tCO2eq) 

DR=10%, TR=40% 

Reduction Option Low High 

Emissions 

Reduction of 

Option 

(MtCO2eq) 

Reduction 

from 2020 

Baseline (%) 

Running Sum 

of Reductions 

(MtCO2eq) 

Cumulative 

Reduction 

from 2020 

Baseline (%) 

Computer controls: SWPB –$2.44 $0.73 1.85 2.4% 1.85 2.4% 

Computer controls: VSS –$5.75 $0.75 8.25 10.7% 10.11 13.1% 

Computer controls: HSS $0.71 $4.75 2.74 3.6% 12.85 16.7% 

Computer controls: CWPB –$16.93 $6.13 4.09 5.3% 16.94 22.0% 

Point feed: SWPB $6.27 $6.98 5.56 7.2% 22.50 29.2% 

Point feed: CWPB –$9.35 $14.17 1.36 1.8% 23.86 31.0% 

Point feed: HSS $19.21 $23.25 2.74 3.6% 26.61 34.5% 

Point feed: VSS $20.37 $26.88 8.25 10.7% 34.86 45.2% 
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GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES IV-149

Table 7-10: Emissions Reduction and Costs in 2020—Technology-Adoption Baseline 

Cost 

(2000$/tCO2eq) 

DR=10%, TR=40% 

Reduction Option Low High 

Emissions 

Reduction of 

Option 

(MtCO2eq) 

Reduction 

from 2020 

Baseline (%) 

Running Sum 

of Reductions 

(MtCO2eq) 

Cumulative 

Reduction 

from 2020 

Baseline (%) 

Computer controls: SWPB –$2.44 $0.73 1.22 2.7% 1.22 2.7% 

Computer controls: VSS –$5.75 $0.75 0.20 0.5% 1.43 3.2% 

Computer controls: HSS $0.71 $4.75 0.80 1.8% 2.23 5.0% 

Computer controls: CWPB –$16.93 $6.13 0.26 0.6% 2.48 5.5% 

Point feed: SWPB $6.27 $6.98 3.67 8.2% 6.16 13.8% 

Point feed: CWPB –$9.35 $14.17 0.09 0.2% 6.24 14.0% 

Point feed: HSS $19.21 $23.25 0.80 1.8% 7.04 15.7% 

Point feed: VSS $20.37 $26.88 0.20 0.5% 7.24 16.2% 

IV.7.4.2 Global and Regional MACs and Analysis 

This section discusses the results from the MAC analysis for the world and by region, including 

China, Japan, the United States, the EU-15, other OECD, and the rest of the world. 

Figure 7-3 presents the 2010 and 2020 global technology-adoption and no-action MACs for aluminum 

production. The difference in abatable emissions between the technology-adoption and no-action MACs 

reflects the impact of retrofits adopted globally to meet IAI’s PFC emissions reduction goal. The 

technology-adoption baseline reflects the IAI goal, which is to reduce the global PFC emissions intensity 

to 80 percent below 1990 levels by 2010. In contrast, the no-action baseline and MACs assume that 

aluminum producers will implement no retrofit actions beyond those necessary to achieve year 2000 

emissions rates. 

For the technology-adoption and no-action global MACs, operational and capital costs for 

implementing retrofits, as well as the global PFC emissions intensities for smelter technologies, are 

assumed to remain constant between 2010 and 2020. Consequently, for both MAC scenarios, changing 

aluminum production levels represents the primary driver for MAC curve shifts between 2010 and 2020. 

Most of this increased production is expected to occur in the other OECD and rest of the world regions 

(specifically in Africa and Latin America). The shift to the right is greater in the no-action global MACs 

because of the larger presence of non-retrofitted smelters in all global regions. That is, while the 

technology-adoption MACs assume that all CWPB, SWPB, as well as a majority of VSS and HSS smelters, 

have been retrofitted to PFPB, the no-action MACs assume that no changes have occurred since 2000. 

Figures 7-4 and 7-5 present 2010 and 2020 regional technology-adoption MACs for China, Japan, the 

United States, the EU-15, other OECD, and the rest of the world. The 2020 regional MACs reflect the 

successful and continuing attainment of IAI’s 2010 global PFC emissions intensity goal, which is expected 

to be achieved by retrofitting Soderberg and SWPB smelters with computer control systems and pointfeeding systems. As a result, relatively limited emissions reductions are available in Japan, the United 

States, China, the EU-15, and other OECD countries in 2010. Where reductions are available, they will 

predominantly occur at those smelters that still utilize HSS and SWPB-based technologies. SWPB retrofits 

to PFPB will generally occur before HSS. SWPB retrofit costs range between –$2.4 and $7/tCO2eq, 

compared with $0.7 to $23/tCO2eq for HSS. In 2010, most VSS smelters are assumed to have undergone 
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IV-150 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

Figure 7-3: 2010 and 2020 Global Technology-Adoption and No-Action MACs for Primary Aluminum 

Production 

Figure 7-4: 2010 Regional Technology-Adoption MACs for Primary Aluminum Production 

EU-15 = European Union; OECD = Organisation for Economic Co-operation and Development 
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GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES IV-151

Figure 7-5: 2020 Regional Technology-Adoption MACs for Primary Aluminum Production 

EU-15 = European Union; OECD = Organisation for Economic Co-operation and Development 

retrofit through voluntary actions, and therefore only limited reductions are still available for this cell 

type. For the remaining rest of the world countries, significant reductions in the MAC will occur in 

Africa, Brazil, and the Russian Federation (i.e., these regions account for over 80 percent, approximately 3 

MtCO2eq, of the rest of the world reductions). For both Africa and Brazil, significant SWPB-based 

production is expected to continue to occur, and thus be available for retrofit to PFPB. In the Russian 

Federation, VSS, HSS, and SWPB-based production is assumed to continue to occur. 

As in 2010, the majority of emissions reductions in 2020 are expected to be available in the rest of the 

world, specifically Africa, Brazil, and the Russian Federation (Figure 7-5). Again reductions are expected 

to occur predominantly through the retrofit of HSS and SWPB smelters. On a global basis, approximately 

70 percent of reductions will occur at SWPB smelters. Because SWPB retrofits are relatively inexpensive, 

this means that most of the reductions (6.2 MtCO2eq) will be available for less than $7/tCO2eq. Another 

0.9 MtCO2eq will be available between $7 and $24/tCO2eq, primarily from the major retrofit of HSS 

smelters. (Major and minor HSS smelter retrofits account for approximately 22 percent of global 

emissions reductions.) The majority of HSS retrofits are expected to occur in China and the Russian 

Federation. 

IV.7.4.3 Uncertainties and Limitations 

Uncertainties and limitations persist despite attempts to incorporate all publicly available 

information on international aluminum production. Some key areas of uncertainty within the aluminum 

MAC modeling methodology are provided below. 

Aluminum Production 

A major source of uncertainty in the MACs is due to variation in aluminum production for all 

countries. Aluminum production is highly variable, with operations coming on- and offline as market 

forces fluctuate; thus, a simple measure of capacity is not always indicative of actual production, 

especially for long-range projections. Also, production fluctuations between cell types within a given 

country can significantly affect the emissions estimates, because different cell types have significantly 
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IV-152 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

different emissions rates. The USEPA modeled documented Soderberg and SWPB to PFPB technology 

shifts (IAI, 2005a) in the no-action and technology-adoption baselines; however, recent environmental 

factors, as well as increasing energy costs, have resulted in the shutdown of many Soderberg smelters 

(Marks, 2006). Consequently, technology mix assumptions used in this analysis may not represent actual 

technology mix conditions in global aluminum markets. 

Baseline Market Penetration of Retrofits 

The USEPA has modeled the baseline market penetration of retrofits in both the no-action and 

technology-adoption scenarios on a cell-type– and country-specific basis. However, the information used 

in the model (from IEA, 2000) is now several years old, and it may not reflect the actual adoption of 

retrofits globally. Thus, the reductions available for the various cell types may be over or underestimated.

Cost Savings 

Benefits associated with reduced energy consumption and fluoride losses were calculated using 

assumptions detailed in Estimating the Cost of an Anode Effect (USEPA, 2002). However, this cost savings is 

dependent on a number of factors, such as the type of power system installed at smelters (e.g., constant 

power consumption systems, which are used by most aluminum smelting facilities; or constant potline 

current or amperage systems), which can vary significantly depending on smelter technology-types, age, 

and operational characteristics. Consequently, conservative assumptions were applied when estimating 

potential cost savings. Generally, these savings were estimated to be on the order of 1 to 4 percent of total 

realized cost savings, of which the primary contributor is avoided aluminum production losses. 

Adjusting Costs for Specific Domestic Situations 

Currently, the technologies considered in this report are widely available. However, individual 

countries may be faced with higher costs from transportation and tariffs associated with purchasing the 

technology from abroad or with lower costs from domestic production of these technologies. Data on 

domestically produced and implemented retrofit technologies in individual countries are not available. 

Emissions Reduction Effectiveness of Retrofit Technologies 

The PFC emissions factor reductions used for the minor and major retrofits may vary significantly 

depending on various operational conditions (e.g., cell conditions, plant operator effectiveness). 

Additionally, as technologies and control software evolve, additional reduction opportunities are likely to 

occur. For example, recently Alcan Pechiney reported improved software and feed systems that have the 

potential to make substantial reductions in emissions on cells that are already considered to be high 

performing relative to PFC emissions (Marks, 2006). Any deviation from the assumed emissions 

reduction potential of the retrofits would have a direct impact on estimated emissions. 

IV.7.5 References 

Dugois, J.P. 1994. Anode Effect Control as a Means to Limit PFC Emissions from Electrolytic Cells. PFC 

Workshop. London, United Kingdom: International Primary Aluminum Institute. 

International Aluminum Institute (IAI). 2000. Perfluorocarbon Emissions Reduction Programme 1990− 2000.

Available at <http://www.world-aluminium.org/iai/publications/pfc.html>. 

International Aluminum Institute (IAI). 2005a. The International Aluminum Institute’s Report on the 

Aluminum Industry’s Global Perfluorocarbon Gas Emissions Reduction Programme—Results of the 2003 

Anode Effect Survey. Available at <http://www.world-aluminium.org/iai/publications/pfc.html>. 

International Aluminum Institute (IAI). 2005b. Aluminum for Future Generations Sustainability Update.

Available at < http://www.world-aluminium.org/iai/publications/documents/update_2004.pdf>. 
SECTION IV — INDUSTRIAL PROCESSES • ALUMINUM PRODUCTION 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES IV-153

International Energy Agency (IEA). 2000. Greenhouse Gas Emissions from the Aluminum Industry. 

Cheltenham, United Kingdom: The International Energy Agency Greenhouse Gas Research & 

Development Program. 

Marks, J. 2006. Personal communication with Jerry Marks, IAI. 

U.S. Environmental Protection Agency (USEPA). March 2002. Estimating the Cost of an Anode Effect. 

Washington, DC: USEPA. 

U.S. Environmental Protection Agency (USEPA). 2006. Global Anthropogenic Non-CO2 Greenhouse Gas 

Emissions: 1990–2020. Washington, DC: USEPA. 
SECTION IV — INDUSTRIAL PROCESSES • ALUMINUM PRODUCTION 

IV-154 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 
SECTION IV — INDUSTRIAL PROCESSES • HCFC-22 PRODUCTION 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES IV-155

IV.8 HFC-23 Emissions from HCFC-22 Production 

IV.8.1 Source Description 

rifluoromethane (HFC-23) is generated and emitted as a by-product during the production of 

chlorodifluoromethane (HCFC-22). HCFC-22 is used both in emissive applications (primarily 

air-conditioning and refrigeration) and as a feedstock for production of synthetic polymers. 

Because HCFC-22 depletes stratospheric ozone, its production for nonfeedstock uses is scheduled to be 

phased out under the Montreal Protocol. However, feedstock production is permitted to continue 

indefinitely. 

Nearly all producers in developed countries have implemented process optimization or thermal 

destruction to reduce HFC-23 emissions. In a few cases, HFC-23 is collected and used as a substitute for 

ODSs, mainly in very-low temperature refrigeration and air-conditioning systems. Emissions from this 

use are quantified in the Air Conditioning and Refrigeration chapters and are therefore not included here. 

HFC-23 exhibits the highest GWP of the HFCs—11,700 under a 100-year time horizon—with an 

atmospheric lifetime of 264 years. Baseline emissions estimates under both a technology-adoption and a 

no-action baseline scenario are presented in Tables 8-1 and 8-2. 

Table 8-1: Total HFC-23 Emissions from HCFC-22 Production (MtCO2eq)—No-Action Baseline 

Country/Region 2000 2010 2020 

Africa 0.0 0.0 0.0 

Annex I 51.0 29.6 26.3 

Australia/New Zealand 0.0 0.0 0.0 

Brazil 0.1 0.2 0.2 

China 33.3 70.2 91.0 

Eastern Europe 0.0 0.0 0.0 

EU-15 6.5 1.8 1.0 

India 4.7 8.0 9.2 

Japan 13.6 0.8 0.9 

Mexico 2.6 4.0 4.3 

Non-OECD Annex I 1.1 0.7 0.3 

OECD 56.2 38.6 36.6 

Russian Federation 1.1 0.7 0.3 

South & SE Asia 0.0 0.0 0.0 

United States 29.8 26.3 24.0 

World Total 95.6 118.0 137.5 

EU-15 = European Union; OECD = Organisation for Economic Co-operation and Development.

T 
SECTION IV — INDUSTRIAL PROCESSES • HCFC-22 PRODUCTION 

IV-156 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

Table 8-2: Total HFC-23 Emissions from HCFC-22 Production (MtCO2eq)—Technology-Adoption Baseline 

Country/Region 2000 2010 2020 

Africa 0.0 0.0 0.0 

Annex I 51.0 11.4 10.1 

Australia/New Zealand 0.0 0.0 0.0 

Brazil 0.1 0.2 0.2 

China 33.3 27.0 47.8 

Eastern Europe 0.0 0.0 0.0 

EU-15 6.5 0.6 0.4 

India 4.7 1.1 2.3 

Japan 13.6 0.8 0.9 

Mexico 2.6 0.3 0.6 

Non-OECD Annex I 1.1 0.7 0.3 

OECD 56.2 15.4 15.3 

Russian Federation 1.1 0.7 0.3 

South & SE Asia 0.0 0.0 0.0 

United States 29.8 9.3 8.5 

World Total 95.6 44.7 66.2 

EU-15 = European Union; OECD = Organisation for Economic Co-operation and Development.

IV.8.1.2 No-Action Baseline 

Under the no-action baseline scenario, it is assumed that HCFC-22 producers will take no further 

action to reduce their emissions; as a result, emissions projections do not reflect anticipated technology 

adoptions to reduce emissions. Under this scenario, world HFC-23 emissions from HCFC-22 production 

are expected to grow by an additional 56 percent between 2000 and 2015, but emissions are expected to 

decline between 2015 and 2020 as a result of the phaseout of nonfeedstock HCFC-22 production in 

developing countries. 

Figure 8-1 reveals a striking shift: the majority of emissions will come from China and other 

developing countries rather than from the OECD countries. This is due to (1) a combination of increased 

use of emissions controls and the phaseout of HCFC-22 under the Montreal Protocol in OECD countries 

and (2) increased HCFC-22 production in China. (These drivers are discussed further below.) Thus, while 

HFC-23 emissions from developed countries are expected to decline by more than 60 percent from 1990 to 

2020 in the no-action baseline, HFC-23 emissions in the China/CPA region are expected to increase 

dramatically. Southeast Asia and Latin America are also projected to show increasing emissions during 

this period. In 1990, the three largest emitters for this source were the United States, Japan, and France, 

which together accounted for more than two-thirds of all emissions. In 2020, the three largest emitters are 

projected to be China, India, and the United States. These nations are anticipated to account for 90 percent 

of all HFC-23 emissions, while China alone is expected to be the world’s major HFC-23 emitter, 

accounting for more than 65 percent of total emissions. 
SECTION IV — INDUSTRIAL PROCESSES • HCFC-22 PRODUCTION 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES IV-157

Figure 8-1: HFC-23 Emissions from HCFC-22 Production Based on a No-Action Scenario—1990–2020 

(MtCO2eq) 

CPA = Centrally Planned Asia; EU-25 = European Union; Non-EU FSU = non-European Union Former Soviet Union countries; S&E Asia =

Southeast Asia; OECD90+ = Organisation for Economic Co-operation and Development. 

In the developed world, HFC-23 emissions decreased between 1990 and 2000 because of process 

optimization and thermal destruction, although there were increased emissions in the intervening years. 

The United States and EU drove these trends in the developed world. Although emissions increased in 

the EU-25 between 1990 and 1995 because of increased production of HCFC-22, a combination of process 

optimization and thermal oxidation led to a sharp decline in EU emissions after 1995, resulting in a net 

decrease in emissions of 67 percent for this region between 1990 and 2000. U.S. emissions also declined by 

15 percent during the same period, despite a 35 percent increase in HCFC-22 production; however, 

during that time period, U.S. emissions demonstrated two distinct trends. Between 1990 and 1995, U.S. 

emissions declined by 23 percent because of a steady decline in the emissions rate of HFC-23 (i.e., the 

amount of HFC-23 emitted per kilogram of HCFC-22 manufactured). However, between 1995 and 2000, 

U.S. emissions increased because of increases in HCFC-22 production.1

As illustrated in Figure 8-1 under the no-action baseline, HFC-23 emissions in developed countries 

are predicted to continue to decrease through 2020 as a result of (1) Japan’s implementation of either 

thermal abatement or HFC-23 capture (for use) for 100 percent of its production beginning in 2005 

(JICOP, 2006), (2) 100 percent implementation of thermal abatement in all EU countries except Spain by 

2010, (3) closure of the HCFC-22 production plant in Greece in 2006, and (4) the HCFC-22 production 

phaseout scheduled under the Montreal Protocol. 

 

1 The apparent increase in U.S. emissions between 2000 and 2005 is an artifact of the method used to estimate U.S. 

emissions in the no-action baseline. Under this approach, the U.S. emissions factor was assumed to revert to its 

relatively high 1990 level in 2005, despite reductions in earlier years. 
SECTION IV — INDUSTRIAL PROCESSES • HCFC-22 PRODUCTION 

IV-158 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

In the developing world, particularly China, emissions are increasing quickly because of a rapid 

increase in the production of HCFC-22. This production is meeting growing demand for unitary airconditioning, commercial refrigeration, and substitutes for CFCs, which are currently being phased out in 

developing countries under the Montreal Protocol (UNEP, 2003). Under the no-action baseline, the 

increase in HFC-23 emissions is expected to continue through 2015, when HCFC-22 itself will begin to be 

phased out by developing countries for most end-uses under the Montreal Protocol. 

IV.8.1.3 Technology-Adoption Baseline 

Under the technology-adoption baseline scenario, it is assumed that HCFC-22 producers will 

introduce technologies and practices aimed at reducing HFC-23 emissions. Under this scenario, global 

HFC-23 emissions from HCFC-22 production are expected to decline by 35 percent between 2000 and 

2020. These trends are mainly a result of the expected implementation of Clean Development Mechanism 

(CDM) projects in China, India, Korea, and Mexico, as well as implementation of thermal oxidation in 

Spain and the HCFC-22 production phaseout scheduled under the Montreal Protocol. 

As seen in Figure 8-2, the most striking trend apparent in the technology-adoption baseline is the 

dramatic decline in emissions from China (and thus for the world, since by 2005 China accounts for the 

majority of emissions) between 2005 and 2010, followed by an increase in emissions from 2010 to 2015, at 

which point emissions again decline. The first dip in this zigzag pattern is caused by the implementation 

of CDM projects in China. Abatement is assumed to begin in 2010, decreasing emissions. However, while 

abatement (in absolute terms) is held constant through 2015 and 2020, emissions grow between 2010 and 

2015 as a result of the increase in production of HCFC-22 in China (discussed in Section 8.1.2). The 

increase in HFC-23 emissions is then reversed after 2015, when HCFC-22 itself will begin to be phased out 

by developing countries for most end-uses. 

Figure 8-2: HFC-23 Emissions from HCFC-22 Production Based on a Technology-Adoption Scenario—

1990–2020 (MtCO2eq) 

CPA = Centrally Planned Asia; EU-25 = European Union; Non-EU FSU = non-European Union Former Soviet Union countries; S&E Asia =

Southeast Asia; OECD90+ = Organisation for Economic Co-operation and Development. 
SECTION IV — INDUSTRIAL PROCESSES • HCFC-22 PRODUCTION 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES IV-159

Emissions in OECD countries are expected to decline by 80 percent between 1995 and 2015. As 

Figure 8-2 shows, the majority of these emissions shift to China and other developing countries. This is 

due to (1) a combination of increased use of emissions controls and the phaseout of HCFC-22 in OECD 

countries and (2) increased HCFC-22 production in China. Thus, while HFC-23 emissions from 

developed countries are expected to decline by more than 80 percent from 1990 to 2020, HFC-23 

emissions in the China/CPA region are expected to increase dramatically, despite the adoption of 

abatement measures under the CDM. Southeast Asia and Latin America are also projected to show 

increasing emissions through this period. 

Global emissions in 1990 to 2000 follow the same trends as in the no-action baseline. As illustrated in 

Figure 8-2, HFC-23 emissions in developed countries as compared with the no-action baseline are 

predicted to decrease from 2010 through 2020, mainly as a result of the U.S. implementation of thermal 

abatement. 

IV.8.2 Cost of HFC-23 Reduction from HCFC-22 Production 

IV.8.2.1 Abatement Options 

Historically, the majority of HFC-23 emissions have been vented to the atmosphere. However, two 

options have been identified as technically viable measures to reduce HFC-23 emissions from HCFC-22 

production (IPCC, 2001): 

• manufacturing process optimization and 

• destruction of HFC-23 by thermal oxidation. 

Process Optimization 

Process optimization and modifications to production equipment can both optimize HCFC-22 

production and reduce HFC-23 emissions. Process optimization is relatively inexpensive and is likely to 

be most effective in reducing the emissions from plants that are generating HFC-23 at a rate of 3 percent 

to 4 percent. Process optimization has been demonstrated to reduce emissions of fully optimized plants to 

below 2 percent of HCFC-22 production. This analysis assumes that all plants in developed countries 

have already implemented some optimization, resulting in HFC-23 emissions reductions. These plants 

may achieve further reductions through additional process optimization, but these reductions are likely 

to be more modest (Rand et al., 1999). Therefore, this option is not explicitly included as a mitigation 

option in this MAC analysis. 

Thermal Oxidation 

Thermal oxidation, the process of oxidizing HFC-23 to CO2, HF, and water, is a demonstrated 

technology for the destruction of halogenated organic compounds. For example, destruction of more than 

99 percent of HFC-23 can be achieved under optimal conditions (i.e., a relatively concentrated HFC-23 

vent stream with a low flow rate) (Rand et al., 1999). In practice, actual reductions will be determined by 

the fraction of production time that the destruction device is actually operating. Units may experience 

some downtime because of the extreme corrosivity of HF and the high temperatures required for 

complete destruction. This analysis assumes a reduction efficiency of 95 percent.2

 

 

2 A representative of a company that manufactures thermal oxidation systems stated that new systems are built using 

materials that better resist corrosion than the materials used in older systems. The representative indicated that such 

new systems were likely to experience very limited downtime, considerably less than 5 percent (Rost, 2006). 
SECTION IV — INDUSTRIAL PROCESSES • HCFC-22 PRODUCTION 

IV-160 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

Although typical incinerators that burn only HFC-23 produce 6 pounds of CO2 for every 1 pound of 

HFC-23 burned, almost all of the CO2 produced is prevented from entering the atmosphere by scrubbers 

in the smoke stack. This reduction in CO2 emissions occurs while scrubbing to remove HF from the waste 

stream (Oldach, 2000). 

Cost and Reduction Assumptions

Cost estimates for thermal oxidation include the following assumptions: 

• In the United States, total installed capital costs for a thermal oxidation system are assumed to be 

approximately $3.4 million per plant in new plants (Rost, 2006) and $4.4 million per plant in 

existing plants3 (Werling, 2006), with total annual operating costs of $334,928 per year (Lehman, 

2002). These capital and annual costs are assumed for the United States and the rest of the world, 

with the exception of the EU. 

• In the EU, the total installed capital costs for a thermal oxidation system were estimated at 

$2,834,447 million per plant, with total annual operating costs of $188,963 per year (Harnisch et 

al., 2000). 

Cost estimates for such systems are based upon the best available industry assessments; actual costs 

of some systems could differ from these estimates. 

Reduction estimates for thermal oxidation include the following assumptions: 

• Based on international HCFC-22 production capacity data from the Chemical Economics 

Handbook (CEH) (2001), the typical HCFC-22 plant outside of the EU was assumed to produce 

20,000 tons of HCFC-22 annually. In the EU, plants were assumed to produce 10,000 tons of 

HCFC-22 annually (Harnisch et al., 2000). 

• Plants were assumed to emit HFC-23 at a rate of 2 percent of HCFC-22 production. 

• As noted above, thermal oxidation was assumed to destroy 95 percent of HFC-23 emissions at 

plants where it was applied. 

Baseline Market Penetration of Thermal Oxidation

The maximum potential market penetration of this option is 100 percent. Thus, the abatement 

potential of the option for any given year and region depends on the difference between the baseline 

market penetration and 100 percent. Tables 8-3 and 8-4 present the baseline market penetration of 

thermal abatement for 2010 and 2020 for the no-action and technology-adoption baseline scenarios. 

The no-action scenario accounts only for the level of implementation of thermal oxidation at the time 

this report was written. It does not account for additional implementation of thermal oxidation in the 

future. (For the United States, the no-action scenario actually assumes that current abatement ceases.) In 

contrast, the technology-adoption scenario accounts for additional implementation in the future. Most 

additional thermal oxidation is assumed to be installed in developing countries as they conduct 

mitigation projects, funded by developed countries under the CDM. The absolute level of abatement (in 

MtCO2eq) for these projects is assumed to remain constant through 2020. Additional thermal oxidation is 

also modeled for Spain, where the owner of the sole HCFC-22 plant has announced plans to install 

thermal oxidation by 2010 (Campbell, 2006). These estimates are discussed in more detail in the USEPA 

report Global Anthropogenic Non-CO2 Greenhouse Gas Emissions: 1990–2020 (2006). 

 

3 Ralph Werling and Kurt Werner of 3M estimated that the costs of installing thermal oxidation systems in existing 

plants were 20 percent to 40 percent greater than the costs of installing the systems in new plants. This analysis 

assumes that it costs 30 percent more to install a thermal oxidation system in an existing plant than in a new plant. 
SECTION IV — INDUSTRIAL PROCESSES • HCFC-22 PRODUCTION 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES IV-161

Table 8-3: Baseline Market Penetration of Thermal Oxidation—No-Action Baseline 

Country 2010 2020 

France 100% 100% 

Germany 100% 100% 

Italy 100% 100% 

Netherlands 100% 100% 

Japan 100% 100% 

Russian Federation 0% 0% 

Spain 0% 0% 

United Kingdom 100% 100% 

United States 0% 0% 

India 0% 0% 

Brazil 0% 0% 

Mexico 0% 0% 

Venezuela 0% 0% 

China 0% 0% 

Korea, Republic of 0% 0% 

Table 8-4: Baseline Market Penetration of Thermal Oxidation—Technology-Adoption Baseline 

Country 2010 2020 

France 100% 100% 

Germany 100% 100% 

Italy 100% 100% 

Netherlands 100% 100% 

Japan 100% 100% 

Russian Federation 0% 0% 

Spain 100% 100% 

United Kingdom 100% 100% 

United States 65% 65% 

India 90% 78% 

Brazil 0% 0% 

Mexico 99% 91% 

Venezuela 0% 0% 

China 65% 50% 

Korea, Republic of 26% 23% 
SECTION IV — INDUSTRIAL PROCESSES • HCFC-22 PRODUCTION 

IV-162 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

Estimating Emissions from New Plants

The analysis also differentiates between emissions coming from new plants and those coming from 

existing plants as different costs are associated with the abatement of these two sets of emissions. To 

calculate emissions from new plants, it is assumed that all emissions growth after 2010 comes from new 

plants. Since only developing countries will experience emissions growth after 2010, all new plants are 

assumed to be built in developing countries. 

IV.8.3 Results 

This section discusses the result from the MAC analysis for the world and several regions for the noaction and technology-adoption scenarios. 

IV.8.3.1 Data Tables and Graphs 

Based on the trends described above, the USEPA developed MACs for the world and several regions. 

Tables 8-5 through 8-8 summarize the potential emissions reduction opportunities and associated costs 

for the world and several regions in 2010 and 2020 for the no-action and technology-adoption baselines. 

The costs to reduce 1 tCO2eq are presented for a discount rate of 10 percent and a tax rate of 40 percent. 

Table 8-5: Emissions Reductions in 2010 and Breakeven Costs ($/tCO2eq) for HFC-23 Emissions from 

HCFC-22 Production at 10% Discount Rate, 40% Tax Rate (MtCO2eq)—No-Action Baseline 

2010 

Country/Region $0 $15 $30 $45 $60 >$60 

Africa 0.00 0.00 0.00 0.00 0.00 0.00 

Annex I 0.00 26.80 26.80 26.80 26.80 26.80 

Australia/New Zealand 0.00 0.00 0.00 0.00 0.00 0.00 

Brazil 0.00 0.19 0.19 0.19 0.19 0.19 

China 0.00 66.69 66.69 66.69 66.69 66.69 

Eastern Europe 0.00 0.00 0.00 0.00 0.00 0.00 

EU-15 0.00 1.14 1.14 1.14 1.14 1.14 

India 0.00 7.58 7.58 7.58 7.58 7.58 

Japan 0.00 0.00 0.00 0.00 0.00 0.00 

Mexico 0.00 3.80 3.80 3.80 3.80 3.80 

Non-OECD Annex I 0.00 0.66 0.66 0.66 0.66 0.66 

OECD 0.00 35.41 35.41 35.41 35.41 35.41 

Russian Federation 0.00 0.66 0.66 0.66 0.66 0.66 

South & SE Asia 0.00 0.00 0.00 0.00 0.00 0.00 

United States 0.00 25.00 25.00 25.00 25.00 25.00 

World Total 0.00 110.78 110.78 110.78 110.78 110.78 

EU-15 = European Union; OECD = Organisation for Economic Co-operation and Development. 
SECTION IV — INDUSTRIAL PROCESSES • HCFC-22 PRODUCTION 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES IV-163

Table 8-6: Emissions Reductions in 2020 and Breakeven Costs ($/tCO2eq) for HFC-23 Emissions from 

HCFC-22 Production at 10% Discount Rate, 40% Tax Rate (MtCO2eq)—No-Action Baseline 

2020 

Country/Region $0 $15 $30 $45 $60 >$60 

Africa 0.00 0.00 0.00 0.00 0.00 0.00 

Annex I 0.00 23.82 23.82 23.82 23.82 23.82 

Australia/New Zealand 0.00 0.00 0.00 0.00 0.00 0.00 

Brazil 0.00 0.20 0.20 0.20 0.20 0.20 

China 0.00 86.43 86.43 86.43 86.43 86.43 

Eastern Europe 0.00 0.00 0.00 0.00 0.00 0.00 

EU-15 0.00 0.67 0.67 0.67 0.67 0.67 

India 0.00 8.72 8.72 8.72 8.72 8.72 

Japan 0.00 0.00 0.00 0.00 0.00 0.00 

Mexico 0.00 4.10 4.10 4.10 4.10 4.10 

Non-OECD Annex I 0.00 0.30 0.30 0.30 0.30 0.30 

OECD 0.00 33.62 33.62 33.62 33.62 33.62 

Russian Federation 0.00 0.30 0.30 0.30 0.30 0.30 

South & SE Asia 0.00 0.00 0.00 0.00 0.00 0.00 

United States 0.00 22.84 22.84 22.84 22.84 22.84 

World Total 0.00 129.51 129.51 129.51 129.51 129.51 

EU-15 = European Union; OECD = Organisation for Economic Co-operation and Development.

Table 8-7: Emissions Reductions in 2010 and Breakeven Costs ($/tCO2eq) for HFC-23 Emissions from 

HCFC-22 Production at 10% Discount Rate, 40% Tax Rate (MtCO2eq)—Technology-Adoption 

Baseline 

2010 

Country/Region $0 $15 $30 $45 $60 >$60 

Africa 0.00 0.00 0.00 0.00 0.00 0.00 

Annex I 0.00 8.72 8.72 8.72 8.72 8.72 

Australia/New Zealand 0.00 0.00 0.00 0.00 0.00 0.00 

Brazil 0.00 0.19 0.19 0.19 0.19 0.19 

China 0.00 23.50 23.50 23.50 23.50 23.50 

Eastern Europe 0.00 0.00 0.00 0.00 0.00 0.00 

EU-15 0.00 0.00 0.00 0.00 0.00 0.00 

India 0.00 0.74 0.74 0.74 0.74 0.74 

Japan 0.00 0.00 0.00 0.00 0.00 0.00 

Mexico 0.00 0.06 0.06 0.06 0.06 0.06 

Non-OECD Annex I 0.00 0.66 0.66 0.66 0.66 0.66 

OECD 0.00 12.18 12.18 12.18 12.18 12.18 

Russian Federation 0.00 0.66 0.66 0.66 0.66 0.66 

South & SE Asia 0.00 0.00 0.00 0.00 0.00 0.00 

United States 0.00 8.06 8.06 8.06 8.06 8.06 

World Total 0.00 37.52 37.52 37.52 37.52 37.52 

EU-15 = European Union; OECD = Organisation for Economic Co-operation and Development.
SECTION IV — INDUSTRIAL PROCESSES • HCFC-22 PRODUCTION 

IV-164 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

Table 8-8: Emissions Reductions in 2020 and Breakeven Costs ($/tCO2eq) for HFC-23 Emissions from 

HCFC-22 Production at 10% Discount Rate, 40% Tax Rate (MtCO2eq)—Technology-Adoption 

Baseline 

2020 

Country/Region $0 $15 $30 $45 $60 >$60 

Africa 0.00 0.00 0.00 0.00 0.00 0.00 

Annex I 0.00 7.66 7.66 7.66 7.66 7.66 

Australia/New Zealand 0.00 0.00 0.00 0.00 0.00 0.00 

Brazil 0.00 0.20 0.20 0.20 0.20 0.20 

China 0.00 43.24 43.24 43.24 43.24 43.24 

Eastern Europe 0.00 0.00 0.00 0.00 0.00 0.00 

EU-15 0.00 0.00 0.00 0.00 0.00 0.00 

India 0.00 1.89 1.89 1.89 1.89 1.89 

Japan 0.00 0.00 0.00 0.00 0.00 0.00 

Mexico 0.00 0.35 0.35 0.35 0.35 0.35 

Non-OECD Annex I 0.00 0.30 0.30 0.30 0.30 0.30 

OECD 0.00 12.32 12.32 12.32 12.32 12.32 

Russian Federation 0.00 0.30 0.30 0.30 0.30 0.30 

South & SE Asia 0.00 0.00 0.00 0.00 0.00 0.00 

United States 0.00 7.36 7.36 7.36 7.36 7.36 

World Total 0.00 58.19 58.19 58.19 58.19 58.19 

EU-15 = European Union; OECD = Organisation for Economic Co-operation and Development.

Table 8-9: World Breakeven Costs and Emissions Reductions in 2020—No-Action Baseline 

Cost 

(2000$/tCO2eq) 

DR=10%, 

TR=40% 

Reduction Option Low High 

Emissions 

Reduction of 

Option 

(MtCO2eq) 

Reduction 

from 2020 

Baseline 

(%) 

Running 

Sum of 

Reductions 

(MtCO2eq) 

Cumulative 

Reduction 

from 2020 

Baseline 

(%) 

Thermal oxidation (new plants) $0.23 $0.23 21.72 15.8% 21.72 15.8% 

Thermal oxidation (existing plants) $0.28 $0.35 107.80 78.4% 129.51 94.2% 

Table 8-10: World Breakeven Costs and Emissions Reductions in 2020—Technology-Adoption Baseline 

Cost 

(2000$/tCO2eq) 

DR=10%, 

TR=40% 

Reduction Option Low High 

Emissions 

Reduction of 

Option 

(MtCO2eq) 

Reduction 

from 2020 

Baseline 

(%) 

Running 

Sum of 

Reductions 

(MtCO2eq) 

Cumulative 

Reduction 

from 2020 

Baseline 

(%) 

Thermal oxidation (new plants) $0.23 $0.23 20.49 31.0% 20.49 31.0% 

Thermal oxidation (existing plants) $0.28 $0.35 37.70 57.0% 58.19 87.9% 
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GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES IV-165

IV.8.3.2 Global and Regional MACs and Analysis 

This section discusses the results from the MAC analysis of the world and selected countries and 

regions, including China, Japan, the United States, the EU-15, other OECD, and the rest of the world. 

Figure 8-3 presents the 2010 and 2020 global technology-adoption and no-action MACs for HCFC-22 

production. As shown in Figure 8-3, the MACs include different cost points depending on the scenario 

and year. The 2020 no-action MAC includes all three cost points: $0.35/tCO2eq for thermal oxidation in 

the EU-15, $0.28/tCO2eq for thermal oxidation at all existing plants in all other regions, and $0.23/tCO2eq 

for thermal oxidation at new plants, which are assumed to exist only in developing countries in 2020. The 

2010 MACs omit the cost point for thermal oxidation at new plants because no new plants are assumed to 

be built until after 2010. Similarly, the technology-adoption MACs exclude the cost point for thermal 

oxidation in the EU because the EU is assumed to have fully implemented thermal oxidation in the 

baseline in the technology-adoption scenario. Costs (in terms of $/tCO2eq) are slightly higher in EU-15 

than in other parts of the world because this analysis uses EU-specific values for capital costs and average 

emissions per facility, which together result in a slightly higher calculated cost per tCO2eq. 

Figure 8-3: 2010 and 2020 Global Technology-Adoption and No-Action MACs for HCFC-22 Production 

As shown in Figure 8-3, in the no-action scenario, HCFC-22 production offers global emissions 

reductions of about 111 MtCO2eq and 130 MtCO2eq in 2010 and 2020, respectively. The 17 percent 

increase in emissions reductions between 2010 and 2020 is a result of baseline emissions increases in 

developing countries, mainly China, between 2010 and 2020. Option costs are not assumed to vary 

between 2010 and 2020; therefore, the additional emissions abatable in 2020 shifts the 2020 MAC slightly 

to the right compared to the 2010 MAC. 

In the technology-adoption scenario, HCFC-22 production offers global emissions reductions of about 

38 MtCO2eq and 58 MtCO2eq in 2010 and 2020, respectively. Available reductions are smaller than in the 

no-action MAC because more emissions are reduced in the technology-adoption baseline. The 55 percent 
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IV-166 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

increase in emissions reductions between 2010 and 2020 is, again, a result of baseline emissions increases 

in developing countries, mainly China, between 2010 and 2020. Figures 8-4 and 8-5 present regional 

MACs for 2010 and 2020 under the technology-adoption scenario. 

Figure 8-4: 2010 Regional Technology-Adoption MACs 

EU-15 = European Union; OECD = Organisation for Economic Co-operation and Development. 

Figure 8-5: 2020 Regional Technology-Adoption MACs 

EU-15 = European Union; OECD = Organisation of Economic Co-operation and Development. 
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GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES IV-167

Large emissions reductions are available in China even in the technology-adoption scenario. These 

result from China’s large expected production of HCFC-22, relatively high emissions rate (3 kg HFC23/100kg HCFC-22), and incomplete adoption of thermal oxidation in the baseline. China’s expected 2010 

HFC-23 emissions make up more than 60 percent of total global emissions in that year, and China’s 

reductions make up 63 percent of the total global reductions. (These percentages differ slightly because 

some of the emissions from other regions are residual emissions that cannot be reduced further.) U.S. 

reductions make up much of the remainder of available reductions because, like China, the United States 

is a large producer of HCFC-22 (accounting for about 20 percent of global production in 2010 and 2020) 

and is also assumed not to fully implement thermal abatement in the baseline. Emissions and reductions 

from other regions are expected to be smaller because of (1) a smaller growth rate for HCFC-22 

production (this growth rate is actually negative in most developed countries because of their ongoing 

phaseout of most uses of HCFC-22 under the Montreal Protocol) and (2) the widespread use of abatement 

technologies in developed countries. 

Large emissions reductions are also available for 2020 in China both in existing and new plants. 

China’s expected 2020 HFC-23 emissions make up 72 percent of total global emissions in that year, and 

China’s reductions make up 74 percent of the total global reductions. 

IV.8.3.3 Uncertainties and Limitations 

This section focuses on the uncertainties associated with the cost estimates presented in this report. 

Uncertainties regarding emissions estimates are discussed in the USEPA report Global Anthropogenic NonCO2 Greenhouse Gas Emissions: 1990–2020 (USEPA, 2006). 

There is some uncertainty associated with the costs of thermal oxidation. Currently, costs are 

available for three versions of thermal oxidation based on data from the United States and the EU, 

respectively. For these two regions, the estimated breakeven prices are expected to be reasonably robust, 

an expectation that is supported by the fact that the breakeven prices for the United States and EU 

versions of the technology are quite similar despite significant differences in capital costs and reductions. 

Outside of the United States and EU, costs and breakeven prices are less certain. U.S. capital costs and 

annual costs were applied to all countries outside of the EU. However, these countries may be faced with 

higher costs from transportation and tariffs associated with purchasing the technology from abroad, or 

with lower costs if there is domestic production of these technologies. 

The estimated cost per tCO2eq is very sensitive to the assumed HCFC-22 production level and HFC23 emissions rate of plants where thermal oxidation is assumed to be installed. The capital cost 

information used in this analysis was for an oxidation system with a 7 to 10 million Btu capacity. This 

capacity is large enough to oxidize HFC-23 emissions from the largest plant in the world, which has a 

production capacity of 100,000 tons. However, because most plants have capacities closer to 20,000 tons, 

this analysis uses that production as the basis for the cost estimates. This may overestimate the 

cost/tCO2eq at larger plants and underestimate it at smaller plants. Similarly, this analysis conservatively 

uses a 2 percent emissions factor in its reduction estimates; plants with higher emissions factors rates 

reduce more emissions by installing thermal abatement. 

Future production levels, emissions rates, and abatement levels are particularly uncertain. Future 

policies (e.g., under the Montreal Protocol) could affect total production of HCFC-22 and therefore 

emissions of HFC-23. Changing emissions rates may also have a significant impact on emissions. In the 

technology-adoption baseline, the USEPA assumed that currently identified CDM projects will be 

implemented in China, India, Korea, and Mexico. However, even after implementation of these projects, 

significant reduction opportunities remain, both in these countries and elsewhere. There is a significant 

probability that many of these emissions will be averted, either through CDM or other mechanisms. In 
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IV-168 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

this case, HFC-23 emissions will be lower than projected in the technology-adoption baseline. Such a 

decrease in emissions would also decrease the reductions available in the technology-adoption MACs. 

IV.8.4 References 

CEH. 2001. Fluorocarbons, CEH Marketing Research Report, 2001. Available from the Chemical Economics 

Handbook—SRI International. 

Harnisch, J., and C.A. Hendriks. 2000. Economic Evaluation of Emission Reductions of HFCs, PFCs and SF6 in 

Europe: Special Report, a contribution to the study “Economic Evaluation of Sectoral Emission 

Reduction Objectives for Climate Change” on behalf of the Directorate General Environment of the 

Commission of the European Union, Prepared by Ecofys Energy and Environment, Brussels. 

Intergovernmental Panel on Climate Change (IPCC). 2001. Climate Change 2001, The Scientific Basis. 

Contribution of Working Group I to the Third Assessment Report of the Intergovernmental Panel on 

Climate Change. Cambridge University Press. 

JICOP. May 9, 2006. E-mails to Deborah Ottinger Schaefer of the USEPA from Mr. Shigehiro Uemura of 

JICOP. 

Lehman, G. 2002. Personal communication with Gail Lehman, General Council, Fluorine Products, 

Corporate Law Department, Honeywell International Inc. 

Oldach, R. 2000. Phone conversation between Robert Oldach, senior engineer with DuPont’s Research 

Group, and Carrie Smith on August 10, 2000. 

Rand, S., D. Ottinger, and M. Branscome. May 26–28, 1999. Opportunities for the Reduction of HFC-23 

Emissions from the Production of HCFC-22. IPCC/TEAP Joint Expert Meeting. Petten, Netherlands. 

Rost, M. April 24, 2006. Personal communication between Marc Rost of T-thermal and Debora Ottinger of 

the USEPA. 

United Nations Environment Programme (UNPE). 2003. Report of the Technology and Economic Assessment 

Panel. HCFC Task Force Report. 

U.S. Environmental Protection Agency (USEPA). 2006. Global Anthropogenic Non-CO2 Greenhouse Gas 

Emissions: 1990–2020. Washington, DC: USEPA. 

Werling, R. April 24, 2006. Telephone conversation between Deborah Ottinger Schaefer of the USEPA and 

Ralph Werling and Kurt Werner of 3M. 
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GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES IV-169

IV.9 PFC and SF6 Emissions from Semiconductor 

Manufacturing 

IV.9.1 Source Description 

he semiconductor industry currently uses several fluorinated compounds (CF4, C2F6, C3F8, 

C4F8, HFC-23, NF3, and SF6) during the fabrication process.1 A fraction of each of these gases is 

emitted during two frequently used manufacturing process steps: the plasma etching of thin 

films and the cleaning of chemical-vapor-deposition chambers.2

 In addition, by-product emissions of CF4

result when a fraction of the heavier gases consumed is converted during the manufacturing process or 

when F-atoms produced in a plasma react with the carbon present in certain low-dielectric strength films 

for CF4. Total PFC emissions from this source vary by process and device type.3 Tables 9-1 and 9-2 

present estimates of historical and forecasted semiconductor manufacturing PFC emissions for 1990 

through 2020 under two different scenarios. 

Table 9-1: Total PFC Emissions from Semiconductor Manufacturing (MtCO2eq)—No-Action Baseline 

Country/Region 2000 2010 2020 

Africa 0.1 0.1 0.2 

Annex I 17.0 47.2 74.3 

Australia/New Zealand 0.0 0.0 0.1 

Brazil 0.0 0.0 0.0 

China 0.8 10.7 37.5 

Eastern Europe 0.2 0.9 1.5 

EU-15 1.9 5.3 8.5 

India 0.2 0.6 1.0 

Japan 7.4 11.0 15.3 

Mexico 0.1 0.0 0.0 

Non-OECD Annex I 0.8 1.5 2.3 

OECD 19.6 59.1 98.1 

Russian Federation 0.8 1.4 2.3 

South & SE Asia 0.6 5.7 28.3 

United States 6.4 28.2 46.1 

World Total 27.4 99.2 231.9 

EU-15 = European Union; OECD = Organisation for Economic Co-operation and Development. 

 

1 The chemical compound CHF3 is more commonly referred to as HFC-23; thus, the latter term is used here. 

2 Very small amounts of CF4 are emitted during a process step called ashing or photoresist stripping. Because 

emissions from this process are considered very small, they are not included. 

3 Note that although the term “PFC” (strictly referring to only perfluorocarbon compounds) does not include all of 

the fluorinated compounds emitted from this source, the semiconductor industry commonly refers to the mix of 

fluorinated compounds as PFCs; this report adopts the same convention. 

T 
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Table 9-2: Total PFC Emissions from Semiconductor Manufacturing (MtCO2eq)—Technology-Adoption 

Baseline 

Country/Region 2000 2010 2020 

Africa 0.1 0.1 0.1 

Annex I 17.0 12.9 10.7 

Australia/New Zealand 0.0 0.0 0.0 

Brazil 0.0 0.0 0.0 

China 0.8 10.7 7.1 

Eastern Europe 0.2 0.9 0.6 

EU-15 1.9 1.2 1.2 

India 0.2 0.6 0.4 

Japan 7.4 3.7 3.7 

Mexico 0.1 0.0 0.0 

Non-OECD Annex I 0.8 1.5 1.0 

OECD 19.6 13.8 12.1 

Russian Federation 0.8 1.4 1.0 

South & SE Asiaa 0.6 5.7 3.8 

United States 6.4 5.5 4.1 

World Total 27.4 36.9 28.3 

a Note that the region South and Southeast Asia (South & SE Asia) in the table above includes different countries than South and East Asia 

(S&E Asia) as defined in the Global Anthropogenic Non-CO2 Emissions: 1990–2020 (USEPA, 2006) and in Figure 9-1. South and East Asia 

in Figure 9-1 includes the major semiconductor manufacturing regions of Taiwan and South Korea, while South and Southeast Asia excludes 

these regions. 

IV.9.1.1 Technology-Adoption Baseline 

The technology-adoption baseline incorporates those reductions that have resulted or are anticipated 

to result from international voluntary climate commitments. In April 1999, the semiconductor 

manufacturing industry set an aggressive target to reduce PFC emissions. The World Semiconductor 

Council (WSC) then agreed to reduce PFC emissions to 10 percent below 1995 levels by the year 2010.4

Because WSC members then accounted for production of over 90 percent of the world’s semiconductors, 

the goal is expected to have dramatic effects in decreasing emissions over time, which would widen the 

gap over time between emissions forecasts shown under the two scenarios presented in Figure 9-1 and 

Figure 9-2 (note that the scales are different in the two graphs). 

OECD and Asia (including China/CPA and South and East Asia) regions are expected to account for 

the vast majority of production, and therefore also the emissions, throughout the time horizon studied. 

The highest-emitting countries worldwide in 2000 were Japan, the United States, Taiwan, South Korea, 

and Germany. By 2010 and through 2020, the highest-emitting country worldwide is expected to be 

China, followed by the United States, Japan, South Korea, Singapore,5

 and Malaysia. The appearance of 

 

4 The base year for South Korea is 1997. 

5 This reflects the top emitting countries in 2020, in descending order of emissions; in 2010, Singapore has greater 

emissions than South Korea. 
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GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES IV-171

Figure 9-1: PFC Emissions from Semiconductor Manufacturing Based on a Technology-Adoption 

Scenario—1990 through 2020 (MtCO2eq) 

CPA = Centrally Planned Asia; EU-25 = European Union; S&E Asia = South and East Asia; Non-EU FSU = non-European Union Former Soviet 

Union countries; OECD90+ = Organisation for Economic Co-operation and Development. 

Figure 9-2: WSC and Non-WSC Countries’ Contribution to Global PFC Emissions (MtCO2eq) 
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IV-172 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

China, Singapore, and Malaysia6 among the top emitting countries reflects a geographic shift in 

production such that the majority of future growth takes place in these countries. This reflects an industry 

trend toward outsourcing production to dedicated manufacturing firms, called foundries, concentrated in 

these countries. 

Global emissions are estimated to have grown at a compound annual growth rate of 11 percent per 

year through the year 2000. Following the introduction of voluntary commitments and resulting 

mitigation efforts, however, a noticeable shift in direction is expected to occur under the technologyadoption scenario. As shown in Figure 9-1, the overall trend in OECD emissions is reflected in the 

emissions from the United States, the European Union (EU-25), and Japan. These regions, where most 

manufacturers are WSC members, are expected to achieve the WSC goal collectively by 2010. In the long 

run, even countries whose manufacturers have not adopted the WSC goal, such as China, Singapore, and 

Malaysia—countries not part of the WSC, are assumed to reduce their emissions rates as new, loweremitting, more productive manufacturing equipment enters the global market. This expectation accounts 

for the reduction in emissions from China and South and East Asia between 2010 and 2020. 

Figure 9-2 shows the relative distribution of global emissions under the technology-adoption scenario 

between WSC and non-WSC members and illustrates these trends even more clearly. Note that emissions 

from WSC countries peaked in 2000. 

IV.9.1.2 No-Action Baseline 

The no-action scenario estimates emissions that would result from normal industry activity with no 

emissions control measures, voluntary or regulation driven. This trajectory can be considered an upper 

bound and can serve as a reference level to which the alternative technology-adoption scenario emissions 

can be compared. The difference between these two emissions sets represents the emissions reductions 

achieved by semiconductor manufacturers as they implement emissions control technologies or other 

mitigation measures. 

Figure 9-3 shows the relative distribution of global emissions under the no-action scenario. As in the 

technology-adoption scenario, the OECD and Asia regions are expected to remain the largest emitters 

throughout the time horizon studied; emissions from these two regions (including OECD90+, China/CPA, 

and South and East Asia) combined are expected to make up 98 percent of global emissions in 2020. 

Historical trends are the same as those presented for the technology-adoption baseline, including the 

11 percent per year annual growth through 2000. However, in the no-action baseline, this high annual 

growth continues virtually unabated through 2010 and is particularly pronounced in Asia beyond 2010. 

In these countries, most notably China, Singapore, and Malaysia, semiconductor manufacturing is 

assumed to increase significantly, as discussed above in the no-action baseline, contributing to higher 

emissions over the time horizon presented. Beyond 2010, the growth rate is assumed to decline by onehalf, reflecting slower growth in demand for semiconductors. Nevertheless, global emissions are expected 

to continue to climb substantially, reaching 232 MtCO2eq by 2020. 

 

6 As of May 2006, China, Singapore, and Malaysia have not joined the WSC. 
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GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES IV-173

Figure 9-3: PFC Emissions from Semiconductor Manufacturing Based on a No-Action Scenario—1990 

through 2020 (MtCO2eq) 

CPA = Centrally Planned Asia; EU-25 = European Union; S&E Asia = South and East Asia; Non-EU FSU = non-European Union Former Soviet 

Union countries; OECD90+ = Organisation for Economic Co-operation and Development. 

IV.9.2 Cost of PFC and SF6 Emissions Reduction from Semiconductor 

Manufacturing 

IV.9.2.1 Abatement Options 

Overview of Options and Analysis 

This analysis considers six different emissions reduction technologies applicable to semiconductor 

manufacturing. These options are shown in Tables 9-3 through 9-8 below. The five main characteristics 

that determine the reductions achieved by each technology in each scenario are (1) whether the 

technology is applicable to plasma etch processes, chemical vapor deposition (CVD) chamber cleaning 

processes, or both; (2) the maximum share of the etch or clean market that is assumed to be claimed by 

the technology relative to a baseline with no preexisting emissions controls; (3) the share of the etch or 

clean market that is already claimed by the technology in the baseline of concern; (4) the reduction 

efficiency of the technology; that is, the percentage by which the technology reduces the emissions stream 

to which it is applied; and (5) for non-WSC countries, the year, because only a fraction of the full 

reductions are assumed to be available to these countries in 2010. Of these characteristics, (4) and 

sometimes (1) affect the cost per tCO2eq of the technology’s reductions, while all five characteristics affect 

the size and shape of the aggregate MACs. 

In general, technologies applicable to CVD chamber cleaning achieve larger reductions than those 

applicable only to etch processes because CVD chamber cleaning is estimated to account for 80 percent of 

the emissions from semiconductor manufacturing, while etch is estimated to account for 20 percent. The 

maximum share of the etch or clean market has been estimated for each technology by region and year 

based on that technology’s cost-effectiveness and applicability, industry trends, and expert judgment. The 
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maximum shares for the no-action scenario are shown below in Tables 9-3 and 9-4. In the no-action 

scenario, none of the technologies is assumed to be implemented in the baseline; thus, the market 

penetrations provided in Tables 9-3 and 9-4 are percentages of the total emissions in the no-action 

scenario for that year. That is, the percentages in Tables 9-3 and 9-4 correspond to the maximum shares 

described in (2) above. 

Table 9-3: Maximum Market Penetrations for WSC Countries in the No-Action Baseline (Percent)a

Option Plasma Etching Process CVD Chamber Cleaning Process 

Thermal destruction 5% 5% 

Catalytic decomposition 5% 5% 

Capture/recovery 15% 15% 

Plasma abatement 70% 0% 

NF3 remote clean 0% 70% 

C3F8 replacement 0% 5% 

a Assumed market penetration of technology, presented as a percentage of no-action baseline emissions that result from etching or CVD 

chamber cleaning, respectively. 

Table 9-4: Maximum Market Penetrations for Non-WSC Countries in the No-Action Baseline (Percent)a

Plasma Etching 

Process 

CVD Chamber 

Cleaning 

Process 

Plasma Etching 

Process 

CVD Chamber 

Cleaning 

Process 

Option 2010 2020 

Thermal destruction 3% 3% 7% 7% 

Catalytic decomposition 3% 3% 8% 8% 

Capture/recovery 2% 2% 5% 5% 

Plasma abatement 30% 0% 75% 0% 

NF3 remote clean 0% 30% 0% 75% 

C3F8 replacement 0% 2% 0% 5% 

a Assumed market penetration of technology, presented as a percentage of no-action baseline emissions that result from etching or CVD 

chamber cleaning, respectively. 

In the technology-adoption scenario, semiconductor manufacturers are assumed to implement 

reduction technologies in the baseline to the extent necessary to achieve the WSC goal. Tables 9-5 and 9-7 

provide the baseline market penetrations of the various technologies in the technology-adoption baseline 

for WSC countries and non-WSC countries, respectively. To estimate the emissions reductions remaining 

in the technology-adoption MACs after implementing the technologies shown in Tables 9-5 and 9-7, the 

shares in Tables 9-5 and 9-7 are subtracted from the corresponding shares in Tables 9-3 and 9-4. The 

resulting percentages are then recast in terms of the emissions that remain unabated in the technologyadoption baseline. (These are different from the total emissions because the technology-adoption baseline 

includes residual emissions from emissions streams to which technologies have already been applied.) 

For example, to obtain the market share for remote clean in the WSC in the 2010 technology-adoption 

baseline, the 57 percent in Table 9-5 is subtracted from the 70 percent in Table 9-3, and the difference is 

then divided by 14 percent, the sum of the remaining, unused shares for the technologies applicable to 

CVD chamber cleaning. These results are shown in Tables 9-6 (for WSC countries) and 9-8 (for non-WSC 

countries). 
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GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES IV-175

Table 9-5: Baseline Market Penetrations for WSC Countries in the Technology-Adoption Baseline (Percent)a

Plasma Etching 

Process 

CVD Chamber 

Cleaning 

Process 

Plasma Etching 

Process 

CVD Chamber 

Cleaning 

Process 

Option 2010 2020 

Thermal destruction 4% 5% 4.8% 5.0% 

Catalytic decomposition 5% 5% 5.0% 5.0% 

Capture/recovery 15% 15% 15.0% 15.0% 

Plasma abatement 57% 0% 67.2% 0.0% 

NF3 remote clean 0% 57% 0.0% 67.2% 

C3F8 replacement 0% 4% 0.0% 4.8% 

a Assumed market penetration of technology, presented as a percentage of no-action baseline emissions that result from etching or CVD 

chamber cleaning, respectively. 

Table 9-6: Maximum Market Penetrations for WSC Countries in the Technology-Adoption Baseline (Percent)a

Plasma Etching 

Process 

CVD Chamber 

Cleaning 

Process 

Plasma Etching 

Process 

CVD Chamber 

Cleaning 

Process 

Option 2010 2020 

Thermal destruction 5% 0% 3% 0% 

Catalytic decomposition 0% 0% 0% 0% 

Capture/recovery 0% 0% 0% 0% 

Plasma abatement 69% 0% 35% 0% 

NF3 remote clean 0% 93% 0% 93% 

C3F8 replacement 0% 7% 0% 7% 

a Assumed market penetration of technology, presented as a percentage of the technology-adoption baseline emissions from etching or CVD 

chamber cleaning that remain available for abatement. 

Table 9-7: Baseline Market Penetrations for Non-WSC Countries in the Technology-Adoption Baseline in 

2020 (Percent)a

Option Plasma Etching Process CVD Chamber Cleaning Process 

Thermal destruction 6% 7% 

Catalytic decomposition 8% 8% 

Capture/recovery 5% 5% 

Plasma abatement 62% 0% 

NF3 remote clean 0% 62% 

C3F8 replacement 0% 4% 

a Assumed market penetration of technology, presented as a percentage of no-action baseline emissions that result from etching or CVD 

chamber cleaning, respectively. 
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Table 9-8: Maximum Market Penetrations for Non-WSC Countries in the Technology-Adoption Baseline 

(Percent)a

Plasma Etching 

Process 

CVD Chamber 

Cleaning 

Process 

Plasma Etching 

Process 

CVD Chamber 

Cleaning 

Process 

Option 2010 2020 

Thermal destruction 3% 3% 6% 0% 

Catalytic decomposition 3% 3% 0% 0% 

Capture/recovery 2% 2% 0% 0% 

Plasma abatement 30% 0% 68% 0% 

NF3 remote clean 0% 30% 0% 94% 

C3F8 replacement 0% 2% 0% 6% 

a Assumed market penetration of technology, presented as a percentage of the technology-adoption baseline emissions from etching or CVD 

chamber cleaning that remain available for abatement. 

For WSC countries, the full reductions from each technology are assumed to be available in 2010, as 

shown in Table 9-3. For non-WSC countries, only 40 percent of the full reductions are assumed to be 

available in 2010, but this percentage grows to 100 percent in 2020, as shown in Table 9-4. 

NF3 Remote Clean Technology 

The NF3 Remote Clean system is used to abate emissions from the chemical vapor deposition (CVD) 

chamber cleaning process and is assumed to be applicable to all fabrication facilities. As noted above, 

CVD chamber cleaning emissions are reported to constitute approximately 80 percent of all 

semiconductor emissions. The system dissociates NF3 using argon gas, converting the source gas to active 

F-atoms in the plasma, upstream of the process chamber. These electrically neutral atoms can selectively 

remove material in the chamber. The by-products of Remote Clean include HF, F2, and other gases, of 

which all but F2 are removed by facility acid scrubber systems. 

This analysis assumes that the emissions reduction efficiency of this option is 95 percent. The 

assumed maximum market penetrations of this option for WSC member countries and non-WSC 

countries in the no-action baseline and technology-adoption baseline are presented in Tables 9-3 through 

9-8. 

Cost and Emissions Reduction Analysis 

• Capital/Upfront Costs. Facilities moving to an NF3 Remote Clean system are assumed to face a 

purchase and installation capital cost of $59,900 per chamber (Burton, 2003a). 

• Annual Costs. Facilities operating NF3 Remote Clean systems are assumed to pay annual fees of 

$11,000 per chamber for a preventative maintenance kit (Burton, 2003a) and to incur additional 

costs equal to the difference in price between NF3 and C2F6. Accounting for the amount of gases 

used and their relative prices, an annual cost of $3,800 per chamber is assumed (Burton, 2003a). 

Therefore, net annual costs are assumed to total $14,800 per chamber. 

• Cost Savings. Facilities that install NF3 Remote Clean systems achieve chamber-cleaning times 

that are 30 to 50 percent faster than baseline C2F6 cleaning times (International SEMATECH, 

1999) and decrease the number of cleanings between wafer passes. The end result is an increase 

in the time devoted to the actual manufacturing portion of the process, which allows highutilization facilities to recoup their capital costs in an estimated 9 months or less. Because of this 
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GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES IV-177

process improvement, assuming a 9-month capital return, it can be calculated that facilities 

receive a cost savings of one and one-third times the capital cost, or $79,867 per chamber, on an 

annual basis. (Burton, 2003b). 

C3F8 Replacement 

C3F8 replacement is used to abate emissions from the CVD chamber cleaning process and is assumed 

to be applicable to all fabrication facilities. The C3F8 simply replaces C2F6, which reduces emissions 

because C2F6 has a 100-year global warming potential (GWP) of 9,200, whereas C3F8 has a 100-year GWP 

of 7,000 and an atmospheric lifetime that is less than one-third that of C2F6 (IPCC, 1996). In addition, C3F8

is more efficiently used/consumed during CVD chamber cleaning than C2F6 (and produces about the 

same amount of CF4 during cleaning), which, combined with the differences in GWP, yields an assumed 

emissions reduction efficiency of 85 percent. The assumed maximum market penetrations for WSC and 

non-WSC countries under the no-action and technology-adoption scenarios are presented in Tables 9-3 

through 9-8. 

Cost and Emissions Reduction Analysis 

• Capital/Upfront Costs. Because the C3F8 simply replaces the C2F6, it is assumed that facilities do 

not incur any capital costs (Burton, 2003a).

• Annual Costs. The cost of C3F8 is assumed to equal the cost of C2F6, so the replacement results in 

no annual costs (Burton, 2003a). 

• Cost Savings. It is assumed that no cost savings are associated with this technology. 

Point-of-Use Plasma Abatement 

The Point-of-Use Plasma Abatement system is used to abate emissions from the plasma etching 

process and is assumed to be applicable to all fabrication facilities. Plasma etching emissions constitute 20 

percent of all semiconductor emissions. The system uses a small plasma source that effectively dissociates 

the PFC molecules that react with fragments of the additive gas—H2, O2, H2O, or CH4—in order to 

produce low-molecular-weight by-products such as HF with little or no GWP. After disassociation, wet 

scrubbers can remove the molecules. The presence of additive gas is necessary to prevent later 

downstream reformation of PFC molecules (Motorola, 1998). The evaluations performed to date indicate 

no apparent interference with the etch process. 

This analysis assumes that the emissions reduction efficiency of this option is 95 percent. The 

assumed maximum market penetrations for WSC and non-WSC countries under the no-action and 

technology-adoption scenarios are presented in Tables 9-3 through 9-8. 

Cost and Emissions Reduction Analysis 

• Capital/Upfront Costs. It is assumed that plasma abatement technology requires capital costs of 

$35,000 per etching chamber, which covers the purchase and installation of the system (Burton, 

2003a). 

• Annual Costs. Facilities with plasma abatement technology are assumed to incur an annual 

$1,000 operational expense per etch chamber (Burton, 2003a). 

• Cost Savings. It is assumed that there are no cost savings associated with this technology. 

Capture/Recovery 

The capture/recovery membrane is used to abate emissions from both the plasma etching and CVD 

chamber cleaning processes and is assumed to be applicable to all fabrication facilities. The 

capture/recovery membrane separates unreacted and/or process-generated PFCs from other gases for 
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IV-178 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

further processing. The treatment process allows for the possibility of some reuse of the captured PFC gas 

(Mocella, 1998). These capture/recovery systems can either reprocess the PFC for reuse or they can 

concentrate the gas for subsequent off-site disposal. Because reprocessing inevitably produces PFC gas 

that is less pure than virgin PFCs, semiconductor process engineers have little or no interest in reusing 

the gas for fear of the possible process-harming impurities (Burton, 2003b). The lack of interest in PFC 

reuse for semiconductor manufacturing combines with the lack of market for reprocessed PFC gas 

outside the industry to make destruction highly attractive (Mocella, 1998; Burton, 2003b). Although a few 

companies have installed pilot PFC capture/recovery systems, this technology is reported to be 

unattractive if NF3 cleaning systems are used, because such cleaning processes do not leave sufficient 

PFCs in the stream to make gas recovery economically viable. In general, removal efficiencies for C2F6, 

CF4, SF6, and C3F8 are in the high 90s, whereas CHF3 and NF3 removal efficiencies fall between 50 percent 

and 60 percent. 

This analysis assumes that the overall emissions reduction efficiency of this option is 96 percent 

(International SEMATECH, 1999). The assumed maximum market penetrations for WSC and non-WSC 

countries under the no-action and technology-adoption scenarios are presented in Tables 9-3 through 9-8.

Cost and Emissions Reduction Analysis 

• Capital/Upfront Costs. Because the equipment is leased, capital costs associated with a 

capture/recovery membrane include only installation and structural changes for preparing the 

facility and its individual chambers for the membrane system. This analysis assumes that total 

capital costs are $1,105,000 per facility, assuming that a standard facility has 200 chambers with a 

4-to-1 ratio of etch chambers to CVD chambers (Burton, 2003a). 

• Annual Costs. Facilities are assumed to lease the equipment and an operator for an annual cost 

of $300,000 (Burton, 2003a). Additionally, they are assumed to incur annual utility charges, which 

encompass gas destruction, water, electricity, and all other costs, of $60,000—for a total annual 

cost of $360,000 per facility. 

• Cost Savings. It is assumed that there are no cost savings associated with this technology. 

Catalytic Decomposition System 

The catalytic decomposition system is used to abate emissions from both the plasma etching and 

CVD chamber cleaning processes and is assumed to be applicable to all fabrication facilities. Catalytic 

decomposition systems are installed in the process after the turbo pump, which dilutes the exhaust 

stream prior to feeding it through the scrubber and emitting the scrubbed gases into the atmosphere. 

Consequently, there is no back flow into the etching tool itself that could adversely affect the performance 

of the etching tool. Because catalytic destruction systems operate at low temperatures, they also produce 

little or no NOx emissions and they demand low volumes of water. Although the technology is applicable 

at all fabrication facilities, off-the-shelf systems must be stream- or process-specification-specific, built to 

reflect a certain minimum concentration and flow of PFC within the exhaust stream. 

This analysis assumes that the emissions reduction efficiency of this option is 99 percent 

(International SEMATECH, 1999). The assumed maximum market penetrations for WSC and non-WSC 

countries under the no-action and technology-adoption scenarios are presented in Tables 9-3 through 9-8.

Cost and Emissions Reduction Analysis 

• Capital/Upfront Costs. The purchase and installation capital costs associated with a catalytic 

decomposition system are assumed to total $250,000 per every four etching chambers (Burton, 

2003a).
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GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES IV-179

• Annual Costs. It is assumed that facilities incur annual costs totaling $19,750 per every four 

etching chambers (Burton, 2003a). These costs are assumed to cover annual waste discharge 

treatments, catalyst replacements, and utility charges. 

• Cost Savings. It is assumed that no cost savings are associated with this technology. 

Thermal Destruction/Thermal Processing Units (TPU) 

The thermal destruction system is used to abate emissions from both the plasma etching and CVD 

chamber cleaning processes and is assumed to be applicable to all fabrication facilities. Thermal 

destruction technology is advantageous because it does not affect the manufacturing process (Applied 

Materials, 1999). However, the combustion devices use significant amounts of cooling water, which 

requires treatment as industrial wastewater. Finally, thermal oxidation may also produce NOx emissions, 

which are regulated air pollutants. 

This analysis assumes that the emissions reduction efficiency of this option is 97 percent. The increase 

in other greenhouse gas emissions, both from the process-related burning of natural gas and from the 

electricity demand, may reduce the efficiency of this option (Burton, 2003a). Future analysis could be 

conducted to quantify the net reduction efficiency, which is expected to be closer to 90 percent (Burton, 

2003a). The assumed maximum market penetrations for WSC and non-WSC countries under the noaction and technology-adoption scenarios are presented in Tables 9-3 through 9-6.

Cost and Emissions Reduction Analysis 

• Capital/Upfront Costs. Thermal decomposition systems are assumed to require capital costs 

totaling $189,850 per every four etching chambers, which covers the purchase of the system, 

installation, natural gas costs, and the installation of a water circulation unit (Burton, 2003a).

• Annual Costs. It is assumed that facilities incur annual costs of $11,100 per every four etching 

chambers to cover system maintenance, waste disposal, and input purchases (Burton, 2003a). 

• Cost Savings. It is assumed that no cost savings are associated with this technology. 

IV.9.3 Results 

IV.9.3.1 Data Tables and Graphs 

Tables 9-9 through 9-12 provide a summary of semiconductor manufacturing emissions reductions at 

a 10 percent discount rate and 40 percent tax rate by cost per metric ton of carbon dioxide equivalent 

(tCO2eq) for various countries/regions of the world in 2010 and 2020 under the no-action and technologyadoption scenarios. Table 9-13 and 9-14 provide a breakdown of the costs associated and the global 

emissions reductions associated with implementing each abatement option under the two baseline 

scenarios in 2020. 

IV.9.3.2 Global and Regional MACs and Analysis 

Global Trends 

This section discusses the results from the MAC analysis of the world and selected countries/regions. 

In the technology-adoption scenario, which is based on the assumption that World Semiconductor 

Council manufacturers meet their global goal of reducing emissions to 90 percent of 1995 levels by 2010, 

worldwide emissions reductions of up to 18.3 MtCO2eq are available in 2010 at a cost below $25/tCO2eq 

In 2020, global reductions of 14.5 MtCO2eq are available at the same cost. In both years, significant 
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Table 9-9: Emissions Reductions in 2010 and Breakeven Costs ($/tCO2eq) at 10% Discount Rate, 40% Tax 

Rate (MtCO2eq)—No-Action Baseline 

2010 

Country/Region $0 $15 $30 $45 $60 >$60 

Africa 0.0 0.0 0.1 0.1 0.1 0.1 

Annex I 25.9 32.4 40.7 43.0 43.0 43.0 

Australia/New Zealand 0.0 0.0 0.0 0.0 0.0 0.0 

Brazil 0.0 0.0 0.0 0.0 0.0 0.0 

China 2.6 2.8 3.7 4.0 4.0 4.0 

Eastern Europe 0.3 0.3 0.4 0.4 0.4 0.4 

EU-15 3.0 3.7 4.7 5.0 5.0 5.0 

India 0.2 0.2 0.2 0.2 0.2 0.2 

Japan 6.2 7.8 9.8 10.3 10.3 10.3 

Mexico 0.0 0.0 0.0 0.0 0.0 0.0 

Non-OECD Annex I 0.4 0.4 0.5 0.6 0.6 0.6 

OECD 33.1 41.5 52.1 55.0 55.0 55.0 

Russian Federation 0.4 0.4 0.5 0.5 0.5 0.5 

South & SE Asia 1.4 1.5 2.0 2.1 2.1 2.1 

United States 16.0 20.0 25.2 26.6 26.6 26.6 

World Total 49.3 61.0 76.9 81.5 81.5 81.5 

EU-15 = European Union; OECD90+ = Organisation for Economic Co-operation and Development. 

Table 9-10: Emissions Reductions in 2020 and Breakeven Costs ($/tCO2eq) at 10% Discount Rate, 40% Tax 

Rate (MtCO2eq)—No-Action Baseline 

2020 

Country/Region $0 $15 $30 $45 $60 >$60 

Africa 0.1 0.1 0.2 0.2 0.2 0.2 

Annex I 42.2 52.5 66.1 69.9 69.9 69.9 

Australia/New Zealand 0.0 0.0 0.1 0.1 0.1 0.1 

Brazil 0.0 0.0 0.0 0.0 0.0 0.0 

China 22.6 24.4 32.3 35.3 35.3 35.3 

Eastern Europe 0.9 1.0 1.3 1.4 1.4 1.4 

EU-15 4.8 6.0 7.6 8.0 8.0 8.0 

India 0.6 0.6 0.9 0.9 0.9 0.9 

Japan 8.7 10.9 13.7 14.4 14.4 14.4 

Mexico 0.0 0.0 0.0 0.0 0.0 0.0 

Non-OECD Annex I 1.4 1.5 2.0 2.2 2.2 2.2 

OECD 55.6 69.6 87.4 92.4 92.4 92.4 

Russian Federation 1.4 1.5 2.0 2.2 2.2 2.2 

South & SE Asia 17.1 18.4 24.4 26.6 26.6 26.6 

United States 26.1 32.7 41.1 43.4 43.4 43.4 

World Total 134.0 160.4 204.6 218.2 218.2 218.2 

EU-15 = European Union; OECD90+ = Organisation for Economic Co-operation and Development. 
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GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES IV-181

Table 9-11: Emissions Reductions in 2010 and Breakeven Costs ($/tCO2eq) at 10% Discount Rate, 40% Tax 

Rate (MtCO2eq)—Technology-Adoption Baseline 

2010 

Country/Region $0 $15 $30 $45 $60 >$60 

Africa 0.0 0.0 0.1 0.1 0.1 0.1 

Annex I 6.7 6.8 8.1 8.2 8.2 8.2 

Australia/New Zealand 0.0 0.0 0.0 0.0 0.0 0.0 

Brazil 0.0 0.0 0.0 0.0 0.0 0.0 

China 2.6 2.8 3.7 4.0 4.0 4.0 

Eastern Europe 0.2 0.2 0.3 0.3 0.3 0.3 

EU-15 0.7 0.7 0.8 0.8 0.8 0.8 

India 0.2 0.2 0.2 0.2 0.2 0.2 

Japan 2.2 2.2 2.6 2.6 2.6 2.6 

Mexico 0.0 0.0 0.0 0.0 0.0 0.0 

Non-OECD Annex I 0.4 0.4 0.5 0.6 0.6 0.6 

OECD 7.7 7.8 9.2 9.3 9.3 9.3 

Russian Federation 0.4 0.4 0.5 0.5 0.5 0.5 

South & SE Asia 1.4 1.5 2.0 2.1 2.1 2.1 

United States 3.2 3.2 3.8 3.8 3.8 3.8 

World Total 14.4 14.8 18.3 19.0 19.0 19.0 

EU-15 = European Union; OECD90+ = Organisation for Economic Co-operation and Development. 

Table 9-12: Emissions Reductions in 2020 and Breakeven Costs ($/tCO2eq) at 10% Discount Rate, 40% Tax 

Rate (MtCO2eq)—Technology-Adoption Baseline 

2020 

Country/Region $0 $15 $30 $45 $60 >$60 

Africa 0.1 0.1 0.1 0.1 0.1 0.1 

Annex I 3.7 3.7 4.1 4.1 4.1 4.1 

Australia/New Zealand 0.0 0.0 0.0 0.0 0.0 0.0 

Brazil 0.0 0.0 0.0 0.0 0.0 0.0 

China 4.2 4.2 5.0 5.0 5.0 5.0 

Eastern Europe 0.4 0.4 0.4 0.4 0.4 0.4 

EU-15 0.4 0.4 0.4 0.4 0.4 0.4 

India 0.2 0.2 0.3 0.3 0.3 0.3 

Japan 1.1 1.1 1.2 1.2 1.2 1.2 

Mexico 0.0 0.0 0.0 0.0 0.0 0.0 

Non-OECD Annex I 0.6 0.6 0.7 0.7 0.7 0.7 

OECD 3.8 3.8 4.2 4.2 4.2 4.2 

Russian Federation 0.6 0.6 0.7 0.7 0.7 0.7 

South & SE Asia 2.2 2.2 2.7 2.7 2.7 2.7 

United States 1.2 1.2 1.3 1.3 1.3 1.3 

World Total 12.5 12.5 14.5 14.5 14.5 14.5 

EU-15 = European Union; OECD90+ = Organisation for Economic Co-operation and Development. 
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IV-182 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

Table 9-13: Emissions Reduction and Costs in 2020—No-Action Baseline 

Cost (2000$/tCO2eq) 

DR=10%, TR=40% 

Reduction Option Low High 

Emissions 

Reduction 

of Option 

(MtCO2eq) 

Reduction 

from 2020 

Baseline 

(%) 

Running 

Sum of 

Reductions 

(MtCO2eq) 

Cumulative 

Reduction 

from 2020 

Baseline (%) 

Remote clean –$67.06 –$67.06 126.1 54.4% 126.1 54.4% 

C3F8 replacement $0.00 $0.00 7.9 3.4% 134.0 57.8% 

Capture/recovery 

(membrane) 

$4.96 $4.96 26.4 11.4% 160.4 69.2% 

Plasma abatement (etch) $16.83 $16.83 31.5 13.6% 191.9 82.8% 

Thermal abatement $24.34 $24.34 12.7 5.5% 204.6 88.2% 

Catalytic abatement $33.17 $33.17 13.7 5.9% 218.2 94.1% 

Table 9-14: Emissions Reduction and Costs in 2020—Technology-Adoption Baseline 

Cost (2000$/tCO2eq) 

DR=10%, TR=40% 

Reduction Option Low High 

Emissions 

Reduction 

of Option 

(MtCO2eq) 

Reduction 

from 2020 

Baseline 

(%) 

Running 

Sum of 

Reductions 

(MtCO2eq) 

Cumulative 

Reduction 

from 2020 

Baseline (%) 

Remote clean –$67.06 –$67.06 13.6 41.7% 11.8 41.7% 

C3F8 replacement $0.00 $0.00 0.8 2.5% 12.5 44.2% 

Capture/recovery 

(membrane) 

$4.96 $4.96 0.4 0.0% 12.5 44.2% 

Plasma abatement (etch) $16.83 $16.83 2.8 6.3% 14.3 50.5% 

Thermal abatement $24.34 $24.34 0.7 0.6% 14.5 51.1% 

Catalytic abatement $33.17 $33.17 0.7 0.0% 14.5 51.1% 

reductions can be achieved at breakeven costs less than or equal to $0/tCO2eq: 14.4 MtCO2eq in 2010 and 

12.5 MtCO2eq in 2020, through implementation of the Remote Clean and C3F8 Replacement options. The 

reductions available in 2020 are smaller than those available in 2010 because both the WSC countries and 

especially the non-WSC countries are assumed to increase their implementation of reduction technologies 

between 2010 and 2020. These reduction efforts outpace production growth, leading to a decline in 

emissions in the technology-adoption baseline. 

In the no-action MAC, under which no mitigation efforts are expected to have been implemented in 

the baseline, available reductions are significantly higher, rising to 81.5 MtCO2eq in 2010 and 218.2 

MtCO2eq in 2020. Of these reductions, over half (49.3 and 134.0 MtCO2eq, respectively) can be achieved at 

$/tCO2eq values less than or equal to $0/tCO2eq. In the no-action scenario, available reductions rise in 

proportion to increased semiconductor production. 

The semiconductor manufacturing industry is treated by this analysis as a global market; the costs of 

mitigation are therefore not expected to differ among manufacturing countries. Thus, each global MAC 

curve has just six cost points. 
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GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES IV-183

Regional Trends in the Technology-Adoption Scenario 

Figures 9-4 and 9-5 present 2010 and 2020 regional MACs for China, Japan, the United States, the EU15, other OECD, and Rest of World for the technology-adoption scenario. China, followed by the United 

States, accounts for the largest available reductions of any single country in 2010. Chinese emissions are 

driven by China’s significant share of global production and especially by the assumption that China, like 

other countries outside the WSC, does not implement reduction technologies until after 2010 in the 

technology-adoption scenario. Similarly, U.S. emissions are driven by the assumptions that the United 

States accounts for 25 percent of global production in 2010 (the largest share of any country in that year) 

and that the U.S. manufacturers that have not committed to the WSC goal (representing approximately 20 

percent of U.S. production) will not meet it in 2010. The aggregate Rest of World region shows the largest 

quantity of emissions reductions available in 2010, largely because this region includes Taiwan, South 

Korea, Singapore, and Malaysia, which collectively account for approximately 30 percent of global 

semiconductor production in 2010. 

In 2020, the emissions reductions available in China grow slightly, whereas those available in the Rest 

of World region remain fairly constant, and those available in the other regions decrease. Although 

baseline emissions from Japan, the United States, the EU-15, and other OECD countries change little 

between 2010 and 2020 in the technology-adoption scenario, the reductions available to these countries 

decrease significantly because more of these reductions are assumed to be implemented in the baseline. 

This can be seen by comparing the 2010 and 2020 baseline market penetrations in Table 9-5 above. 

Although Chinese baseline emissions decline from 2010 to 2020, potential reductions grow because 

the market penetration of the abatement technologies increases as technologies become fully available in 

countries outside the WSC. This trend is shown in Table 9-4. For the rest of the world region, which is 

composed of both WSC members (Taiwan and South Korea) and non-WSC members (Malaysia and 

Singapore), the decreases in reductions in the WSC counteract the increases in reductions elsewhere, 

keeping available emissions reductions relatively constant from 2010 to 2020. 

IV.9.3.3 Uncertainties and Limitations 

The costs and savings presented in the above section are specific to individual technologies that 

represent potential emissions mitigation options for the semiconductor manufacturing industry. The 

assumptions that form the basis for these figures rely upon expert review of several options that were 

believed to be favored by industry at the time of review. Discussions with industry scientists and analysts 

contributed to capital and operating cost figures and were conducted in mid-2003. 

Considering the rapid growth that characterizes the semiconductor manufacturing industry, it is 

possible that both the relative and absolute costs of some options have changed over the last 3 years. For 

the most part, the USEPA believes that recent changes will not change the relative ranking of the options 

in the market. However, capture/recovery may be an exception to this. Capture/recovery, while 

technologically feasible, also appears to present PFC cost and manufacturing risks that managers and 

process engineers appear unwilling to take. Qualitatively, this suggests that more catalytic and thermal 

decomposition abatement technology might be adopted than indicated in the tables and discussions in 

this section. Further research might provide information for updating both the maximum market 

penetrations and the baseline market penetrations that were assumed to apply in the technologyadoption baseline (see Tables 9-2 through 9-8). 
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IV-184 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

Figure 9-4: 2010 Regional Technology-Adoption MACs for Semiconductor Manufacturing 

EU-15 = European Union; OECD90+ = Organisation for Economic Co-operation and Development. 

Figure 9-5: 2020 Regional Technology-Adoption MACs for Semiconductor Manufacturing 

EU-15 = European Union; OECD90+ = Organisation for Economic Co-operation and Development. 

Capital and operating costs in the United States were assumed to apply to all semiconductor 

manufacturing countries. This simple assumption is supported by the fact that the semiconductor 

manufacturing industry represents a global market with relatively few international suppliers of 

equipment and technology. Because fabrication facilities worldwide likely purchase equipment from the 

same few suppliers, it is assumed that their costs remain the same. This approach is therefore justified as 

a simplifying assumption, but it does not address any fab- or country-specific cost factors that may have 
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GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES IV-185

effects on costs, such as energy prices and labor costs. Further research might provide justification for 

country- or region-specific costs or scaling factors. 

The MACs in this analysis (in terms of reduction percentages) were developed on a regional basis. 

That is, within the WSC, countries were assumed to have identical percentages of their baselines available 

for abatement in any given year and scenario. Similarly, countries outside of the WSC were assumed to 

have identical percentages of their baselines available for abatement, although these percentages were 

different from those of the WSC countries. By distinguishing between the WSC and non-WSC countries, 

this analysis accounts for much of the variation among countries in their emissions patterns and 

reduction opportunities. However, even within the WSC, some countries are expected to make deeper 

reductions than others to meet the WSC goal. This is because production has shifted from some countries, 

such as Japan, to others, such as Taiwan, since the mid- to late 1990s. Thus, in the technology-adoption 

baseline, this analysis may slightly underestimate the reduction opportunities that remain in Japan and 

overestimate those that remain in Taiwan. 

IV.9.4 References 

Applied Materials. 1999. Catalytic Abatement of PFC Emissions. Presented at Semicon Southwest 99: A 

Partnership for PFC Emissions Reductions, October 18, 1999, Austin, TX. 

Burton, S. 2003a. Personal communication with Brown of Motorola (2002) supplemented by personal 

communication with Von Gompel of BOC Edwards (2003), research of DuPont’s Zyron Web site 

(2003), and personal communication with Air Liquide regarding thermal destruction, NF3 Remote 

Clean, and Capture Membrane unit costs. 

Burton, S. May 2003b. Personal communication with ICF Consulting. 

Intergovernmental Panel on Climate Change (IPCC). 1996. Climate Change 1995, The Science of Climate 

Change. Contribution of Working Group I to the Second Assessment Report of the Intergovernmental 

Panel on Climate Change. Cambridge University Press. 

International SEMATECH. October 18, 1999. Motorola Evaluation of the Applied Science and Technology, Inc. 

(ASTex) ASTRON Technology for perfluorocompound (PFC) Emissions Reductions on the Applied Materials 

DxL Chemical Vapor Deposition (CVD) Chamber. Presented at Semicon Southwest 99: A Partnership for 

PFC Emissions Reductions, Austin, TX. 

Mocella, M.T. 1998. PFC Recovery: Issues, Technologies, and Considerations for Post-Recovery Processing. 

Dupont Fluoroproducts, Zyron Electron Gases Group. (Available on the Internet at 

http://www.dupont.com/zyron/techinfo/monterey98.html). 

Molina, Wooldridge, and Molina. 1995. Atmospheric Geophysical Research Letters. 22(13). 

Motorola. October 18, 1998. Long-term Evaluation of Litmus “Blue” Inductively-Coupled Plasma Device for 

Point-of-Use PFC and HFC Abatement. Presented at Semicon Southwest 99: A Partnership for PFC 

Emissions Reductions, Austin, TX. 

U.S. Environmental Protection Agency (USEPA). 2006. Global Anthropogenic Non-CO2 Greenhouse Gas 

Emissions: 1990–2020. Washington, DC: USEPA. 

World Fab Watch. 2002. Semiconductor Equipment and Material International, 2002. 
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IV-186 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 
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GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES IV-187

IV.10 SF6 Emissions from Electric Power Systems 

IV.10.1 Source Description 

ulfur hexafluoride (SF6) is a colorless, odorless, nontoxic, and nonflammable gas with a GWP 

that is 23,900 times that of CO2 during a 100-year time horizon and an atmospheric lifetime of 

3,200 years (USEPA, 2005). SF6 is used as both an arc-quenching and insulating medium in 

electrical transmission and distribution equipment. Several factors affect SF6 emissions from electrical 

equipment, including the type and age of SF6-containing equipment and the handling and maintenance 

protocols used by electric utilities. Historically, approximately 20 percent of total global SF6 sales have 

gone to electric power systems, where the SF6 is believed to have been used primarily to replace emitted 

SF6. Approximately 60 percent of global sales have gone to manufacturers of electrical equipment, where 

the SF6 is believed to have been mostly banked in new equipment (Smythe, 2004). 

SF6 emissions from electrical equipment used in transmission and distribution systems occur through 

leakage and handling losses. Leakage losses can occur at gasket seals, flanges, and threaded fittings and 

are generally larger in older equipment. Handling emissions occur when equipment is opened for 

servicing, SF6 gas analysis, or disposal. Baseline emissions estimates under both a Technology-Adoption 

and a no-action baseline scenario are presented in Table 10-1. 

Table 10-1: Total SF6 Emissions from Electric Power Systems (MtCO2eq)—No-Action Baseline 

Country/Region 2000 2010 2020 

Africa 0.5 1.8 2.5 

Annex I 20.5 27.3 28.6 

Australia/New Zealand 0.3 0.8 0.8 

Brazil 0.5 1.6 2.4 

China 1.8 9.0 14.9 

Eastern Europe 0.4 0.8 0.8 

EU-15 1.9 1.9 1.9 

India 0.7 2.4 3.5 

Japan 0.5 0.4 0.4 

Mexico 0.3 1.0 1.6 

Non-OECD Annex I 1.5 3.9 3.9 

OECD 19.5 25.8 28.0 

Russian Federation 1.1 2.9 2.9 

South & SE Asia 0.6 2.4 3.2 

United States 15.0 17.6 18.9 

World Total 26.8 52.3 65.8 

EU-15 = European Union; OECD = Organisation for Economic Co-operation and Development. 

S 
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IV-188 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

IV.10.1.1 Technology-Adoption Baseline 

As shown in Table 10-2, global emissions from electric power systems are believed to have fallen 

significantly between 1990 and 2000, based on SF6 sales to utilities and estimated equipment retirements. 

This decline was due to a significant increase in the cost of SF6 gas in the mid-1990s, which motivated 

electric utilities to implement better management practices to reduce their use of SF6. However, sales of 

SF6 increased by more than 37 percent between 2000 and 2003, reversing the trend (Smythe, 2004). In 

addition, equipment retirements (based on a 40-year equipment lifetime) are estimated to have more than 

doubled between 2000 and 2003. Together, these two trends resulted in an estimated 55 percent increase 

in global emissions between 2000 and 2003, creating emissions levels similar to those observed in 1990. 

Table 10-2: Total SF6 Emissions from Electric Power Systems (MtCO2eq)—Technology-Adoption Baseline 

Country/Region 2000 2010 2020 

Africa 0.5 1.8 2.5 

Annex I 20.5 21.8 20.3 

Australia/New Zealand 0.3 0.8 0.8 

Brazil 0.5 1.6 2.4 

China 1.8 9.0 14.9 

Eastern Europe 0.4 0.7 0.7 

EU-15 1.9 1.4 0.9 

India 0.7 2.4 3.5 

Japan 0.5 0.3 0.3 

Mexico 0.3 1.0 1.6 

Non-OECD Annex I 1.5 3.9 3.9 

OECD 19.5 20.3 19.8 

Russian Federation 1.1 2.9 2.9 

South & SE Asia 0.6 2.4 3.2 

United States 15.0 12.8 11.8 

World Total 26.8 46.8 57.5 

EU-15 = European Union; OECD = Organisation for Economic Co-operation and Development. 

These global trends are reflected in the trends of the individual regions except for the United States; 

EU-25; Norway, Switzerland, and Iceland (EU-25+3); and Japan. For the United States, emissions 

estimates for 1990 through 2003 are taken from the Inventory of U.S. Greenhouse Gas Emissions and Sinks: 

1990–2003 (USEPA, 2005). For EU-25+3, emissions estimates for 1990 through 2020 were obtained from 

Reductions of SF6 Emissions from High and Medium Voltage Electrical Equipment in Europe (Ecofys, 2005). For 

Japan, emissions estimates for 1990 through 2010 were obtained from Recent Practice for Huge Reduction of 

SF6 Gas Emissions from GIS&GCB in Japan (Yokota et al., 2005), as well as personal communications with T. 

Yokota (2006). These studies show declining emissions in these regions through 2003. 

As illustrated in Figure 10-1, beyond 2005, emissions in developed countries are expected either to 

remain steady or to decline. Emissions in non-EU Eastern Europe and non-EU FSU are expected to 

remain relatively constant through 2020. Because the electric grids in these countries are mature and well 

developed, it is assumed that there will be no additional growth of emissions from their electric 

transmission and distribution systems. Any system growth is expected to be offset by decreases in the 

equipment’s average SF6 capacity and emissions rate as new, small, leak-tight equipment gradually 
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GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES IV-189

Figure 10-1: SF6 Emissions from Electric Power Systems on a Technology-Adoption Scenario—1990–

2020 (MtCO2eq) 

CPA = Centrally Planned Asia; EU-25 = European Union; Non-EU FSU = non-European Union Former Soviet Union countries; S&E Asia =

Southeast Asia; OECD90+ = The Organisation for Economic Co-operation and Development. 

replace old, large, leaky equipment. In the United States, EU-25+3, and Japan, emissions are expected to 

continue to decline as utilities, through government-sponsored voluntary and mandatory programs, 

implement reduction measures such as leak detection and repair and gas recycling practices. 

In contrast, emissions from developing regions (i.e., Latin America, South and East Asia, Middle East, 

Africa and China/CPA) are expected to continue growing during the next 15 years. In these regions, it is 

assumed that SF6-containing equipment has been installed relatively recently and that all equipment is 

new. Consequently, as infrastructure expands to meet the demands of growing populations and 

economies, emissions are estimated to grow at a rate proportional to country- or region-specific net 

electricity consumption (USEIA, 2002). This growth drives global emissions growth, resulting in 

worldwide emissions of 57 MtCO2eq in 2020. By 2020, Latin America, South and East Asia, the Middle 

East, Africa, and China/CPA are expected to account for 63 percent of total emissions, versus 

approximately 10 percent in 1990. OECD is projected to account for only 29 percent of global emissions in 

2020, versus approximately 82 percent in 1990. 

IV.10.1.2 No-Action Baseline 

As illustrated in Figure 10-2, baseline emissions for the period 1990 through 2000 follow the same 

trajectory as those under the technology-adoption scenario, with both baselines diverging after 2003. 

Assumptions and emissions estimates for developing regions (i.e., Latin America, South, and East Asia, 

Middle East, Africa and China/CPA) are the same as discussed under the technology-adoption baseline. 

For the United States, Japan, EU-25, and EU-25+3, it is assumed that no additional voluntary measures are 

adopted after 2003. For the United States, EU-25+3, and Japan, emissions are expected to increase from 

2003 levels, with system growth being the driver in the EU and Japan. The marked increase in U.S. 
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Figure 10-2: SF6 Emissions from Electric Power Systems on a No-Action Scenario—1990–2020 

(MtCO2eq) 

CPA = Centrally Planned Asia; EU-25 = European Union; Non-EU FSU = non-European Union Former Soviet Union countries; S&E Asia =

Southeast Asia; OECD90+ = The Organisation for Economic Co-operation and Development. 

emissions after 2000 is an artifact of the method used to estimate U.S. emissions in the no-action scenario. 

Under this approach, the U.S. emissions factor was assumed to revert to its relatively high 1999 level in 

2005, despite reductions in earlier years. 

The assumption that the United States, EU-25+3, and Japan will pursue no additional voluntary 

measures after 2003 increases their contribution to world emissions in 2020. Unlike the technologyadoption baseline, where OECD accounts for only 29 percent of emissions in 2020, in the no-action 

baseline, OECD accounts for 38 percent. In contrast, the contribution of developing regions, such as Latin 

America, South and East Asia, the Middle East, Africa, and China/CPA decreases to 55 percent of total 

2020 emissions in the no-action scenario, versus 63 percent under the technology-adoption scenario. 

IV.10.2 Cost of SF6 Emissions Reduction from Electric Power 

Systems 

IV.10.2.1 Abatement Options 

SF6 emissions during use of electrical equipment can occur either during the maintenance and 

disposal of equipment or during the operation of equipment because of the failure of mechanical seals or 

breaks in gas-insulated equipment enclosures. 

For all countries except the EU-25, EU-25+3, and Japan, this analysis models three potential 

abatement options for reducing SF6 emissions from electric power systems: 

• SF6 recycling, 

• leak detection and repair (LDAR), and 
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GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES IV-191

• equipment refurbishment. 

For the EU-25+3 and Japan, this analysis models the abatement options identified in Ecofys (2005), 

because the baseline emissions for Europe (in both the no-action and technology-adoption scenarios) are 

based on data presented in Ecofys (2005). Using the Ecofys options therefore maintains consistency with 

the assumptions used in that report to estimate current and future emissions (i.e., current and future 

levels of implementation of reduction options). These options are applied to Japan, because Japan is 

believed to have implemented reduction options to approximately the same extent as Europe. The 

following options are identified in Ecofys: 

• awareness, including training, monitoring, and labeling; 

• evacuation of equipment; 

• repair or replacement; and 

• decommissioning infrastructure. 

Although Ecofys (2005) identifies four options, they are, for the most part, similar in nature to those 

analyzed for countries other than the EU-25+3 and Japan in this study. For example, evacuation of 

equipment is similar to the SF6 recycling option in that both address the recovery of SF6 from closed 

pressure equipment. Decommissioning infrastructure also includes recovery of gas, in this case from 

retiring equipment. Repair and replacement includes activities similar to those included in both the 

LDAR and refurbishment options. As for awareness, some of the associated training costs and emissions 

reductions are accounted for within the SF6 recycling option. The remainder of Section IV.10.3 provides 

an overview of each abatement option and details the associated emissions and cost assumptions. 

Abatement Options—For All Countries Except EU-25+3 and Japan 

Emissions Available for Abatement 

For most of the other sectors in this analysis, the quantity of emissions that can be abated through the 

applicable abatement options is estimated directly based on the activity level and the fraction of the 

emitting activity that remains uncontrolled in the baseline. For this sector, however, the analysis begins 

with an emissions estimate rather than an activity level, making the estimate of uncontrolled emissions 

somewhat more complicated. To develop the estimate of currently uncontrolled emissions, the technical 

applicability, current market penetration, and reduction efficiency of the three abatement options are 

estimated and applied to the hypothetical emissions that would result if emissions were not controlled at 

all. Using this approach, it is possible to estimate the fraction of current emissions that consist of residual 

emissions from the options as they are implemented in the baseline, as well as the fractions of current 

emissions that can still be abated by the three options. For equipment whose emissions are not controlled, 

33 percent of emissions are estimated to occur during operation as a result of leaks, and 67 percent are 

estimated to occur during maintenance and disposal as a result of failure to recycle. This apportionment 

is inferred from O’Connell et al. (2002), who report that leakage losses account for between 0.5 percent 

and 1 percent per year, and handling losses account for between 1 percent and 2 percent per year. Based 

on discussions with electric utilities and manufacturers of SF6 recycling equipment, this analysis assumes 

that recycling, LDAR, and refurbishment options are currently applied to 80 percent of electrical 

equipment. In addition, the analysis assumes that those utilities that currently recycle SF6 recover 80 

percent of the gas each time. That is, 80 percent of the gas enclosed in electrical equipment is assumed to 

be removed as the enclosure pressure drops from operational conditions to zero pounds per square inch 

(psig). The abatement option described below assumes that, in the presence of a carbon price, an 

additional 15 percent of the SF6 will be recovered—95 percent overall—which requires pulling a vacuum 

on the equipment. This is within the technical capability of the equipment but is relatively time 

consuming. Together, all of these assumptions lead to the conclusion that 49 percent of the baseline 
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IV-192 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

emissions remain available to abatement through recycling, 7 percent remains available to abatement 

through LDAR, and 1 percent remains available to abatement through refurbishment. 

SF6 Recycling 

For equipment whose emissions are not controlled, 67 percent of emissions are estimated to occur 

during equipment servicing and disposal. This estimate is based on information reported by the 

International Council on Large Electric Systems (CIGRE) (O’Connell et al., 2002), which indicates that 

leakage and handling losses are on the order of between 0.5 percent and 1 percent per year and 1 percent 

to 2 percent per year, respectively. Recycling gas cart systems typically withdraw, purify, and return the 

SF6 gas to the gas-insulated equipment. Recycling equipment vendors state that utilities that use the 

equipment typically recover about 80 percent of the gas held in high-voltage equipment, although 

recycling equipment is theoretically capable of capturing almost 100 percent. Typically, utilities end 

recovery early because the current price of the SF6 does not justify spending the additional time required 

to recover it fully. In other words, it would take as much time to recover the final 20 percent of the gas as 

it takes to recover the first 80 percent (by mass), because the density of the gas declines during the 

recovery process. Consequently, it is assumed that 80 percent recovery is the current standard industry 

practice. 

The use of recycling equipment is considered a relatively straightforward option for conservative gashandling practices, and gas cart ownership and use have increased significantly worldwide (O’Connell et 

al., 2002; Ellerton, 1997). Communications with gas cart manufacturers have also indicated that the 

majority of electric utilities in North and South America use recycling equipment (ICF, 2001). This 

analysis assumes that the current and future market penetration of recycling equipment in the baseline is 

80 percent in both developed and developing countries. 

In the presence of a carbon price, this analysis assumes that utilities that currently recover SF6 will 

recover it more deeply, recovering 95 percent of the gas rather than the current 80 percent, and the 

analysis assumes that the 20 percent of utilities that do not currently recover SF6 will begin recovering it 

to the 95 percent level. Based on these assumptions, approximately 39 percent of the emissions reductions 

for recycling are achieved through deeper recovery (going from 80 percent to 95 percent), while 61 

percent of these reductions are achieved by increasing the market share of recycling. 

Cost and Emissions Reduction Analysis 

• Capital/Upfront Costs. The capital cost for smaller-capacity recycling equipment is between 

$5,000 and $50,000 per unit and for higher-capacity units between $50,000 and $130,000 per unit 

(ICF, 2001). Because older, larger electrical equipment is being replaced with newer, smaller 

volume electrical equipment in developed countries, and because developing countries, which 

have newer electrical T&D networks, use smaller electrical equipment, an average cost of $25,500 

per unit was assumed. Total country-specific capital costs were calculated by estimating the 

number of recycling gas cart units required to ensure 100 percent market penetration. In the 

United States, it is estimated that between 750 and 1,000 recycling gas carts are in use, based on 

communications with gas cart manufacturers (ICF, 2001). Based on the assumption that this 

number represents an 80 percent market penetration, the number of recycling units required to 

establish a 100 percent U.S. market penetration was estimated to be between 190 and 250 units. 

For other countries, the number of recycling units that can still be implemented, based on an 

existing 80 percent market penetration scenario, was estimated as the product of the number of 

recycling units required to achieve 100 percent market penetration in the United States and the 

ratio of country-specific net electricity consumption to U.S. net electricity consumption (USEIA, 

2002). 
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GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES IV-193

• Annual Costs. Equipment recycling rates range from 50 to 500 pounds SF6 per hour (Dilo, 2003; 

Cryoquip, 2003). Actual recovery speeds depend on recovery pump equipment, operating 

pressure, and connecting equipment. As a conservative estimate, and considering that most SF6

users will require smaller-grade equipment because of smaller charge sizes, the average recovery 

rate for removing gas held under positive pressure (i.e., 80 percent by mass) is assumed to be 100 

pounds SF6 per hour. However, once a vacuum is drawn, the average recovery rate falls below 

this level. Based on the assumption that 100 pounds per hour represents the average recovery 

rate for recovering the first 80 percent of gas (achieving zero psig), average recovery rates were 

calculated for recovery of the gas from its initial pressure to a vacuum (95 percent recovery), 

which is applicable to the utilities that are not currently conducting recycling (i.e., 20 percent of 

the market) and recovery of the gas from zero psig to a vacuum (15 percent), which is applicable 

to the 80 percent of the market that currently only achieves 80 percent recovery. These average 

recovery rates were 64 and 22 pounds per hour, respectively. The marginal labor time required 

for recycling the gas is equal to the total gas recycled in the country multiplied by the estimated 

emissions that can be reduced by increasing the market penetration of recycling (61 percent) and 

increasing the depth of recovery from 80 percent to 95 percent (39 percent), and dividing by the 

corresponding average recycling rate (64 and 22 pounds per hour, respectively). Associated labor 

costs were estimated for a two-person crew and assumed an hourly labor rate of $50 per hour. To 

account for additional labor time spent for training and setting up/tearing down recycling 

equipment, conservative multipliers of 1.02 (i.e., assuming 2 percent [1 week] of annual labor 

time spent conducting training) and 1.5 were also applied. 

• Cost Savings. It is assumed that all SF6 recycled is a cost savings, because the facility’s SF6

purchase and consumption rate will decrease. For this analysis, it is assumed that the cost of SF6

is $7 per pound. 

Leak Detection and Repair

LDAR abatement options aim to identify and reduce the SF6 leakage that occurs from gas-insulated 

equipment. For equipment whose emissions are not controlled, 33 percent of emissions are estimated to 

occur during equipment operation, with 30 percent controllable through LDAR. SF6 leak detection is 

accomplished through various techniques, including “sniffing” for gas with SF6 gas sensors and using 

laser-based remote sensing technology (McRae, 2000). Similar to SF6 recycling, the current market 

penetration of this option is assumed to be 80 percent of SF6 use. LDAR measures are assumed to have a 

reduction efficiency of 50 percent. 

Cost and Emissions Reduction Analysis 

• Capital/Upfront Costs. Leak detection equipment costs vary depending on the type of 

instrument used. For simple screening devices, costs are believed to be minimal (i.e., less than 

$2,000 per unit). For expensive items, such as the laser-based imaging system, it is assumed that 

facilities will lease equipment or contract private companies to provide leak detection services. 

Hence, LDAR mitigation options will have no capital costs. 

• Annual Costs. It is assumed that the average leak size is 25 pounds SF6 per leak per year and that 

the average time to detect and repair a leak is 2 and 8 hours, respectively (ICF, 2000). The 

marginal labor time required for LDAR is equal to the total gas emitted from this source divided 

by the average leak size and multiplied by the average time to detect and service a leak. 

Associated labor costs assume LDAR requires a one-person and two-person crew, respectively, 

and that the hourly labor rate is $50 per hour. 
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IV-194 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

• Cost Savings. It is assumed that all SF6 saved during leak detection and maintenance activities 

represents a cost savings, because the facility SF6 purchase and consumption rate will decrease. 

For this analysis, it is assumed that the cost of SF6 is $7 per pound. 

Equipment Refurbishment

Unlike LDAR-based repairs, which tend to focus on small leaks on specific components, such as a 

bushing flange gasket, refurbishment addresses the need, when leakage losses are large, for a 

comprehensive repair. Refurbishment is a process in which equipment is disassembled and rebuilt (and 

possibly upgraded) using remachined, cleaned, and/or new components. Generally, equipment 

refurbishment represents the cheaper of two possible options: 1) equipment replacement, which for a 

large breaker (362 kV) can be on the order of $300,000 to $400,000; and 2) refurbishment, which may cost 

around $100,000 (McCracken et al., 2000).

It is assumed that 33 percent of uncontrolled emissions occur during equipment operation; of this 

total, 3 percent is assumed to be controllable through refurbishment. Similar to the other options, 

refurbishment is assumed to have a current market penetration of 80 percent. Refurbishment measures 

are assumed to have a reduction efficiency of 95 percent. 

Cost and Emissions Reduction Analysis 

• Capital/Upfront Costs. The cost of labor and parts to undertake the refurbishment of a circuit 

breaker with a nameplate capacity of 1,500 pounds and a leak rate of 20 percent is assumed to be 

approximately $100,000 (McCracken et al., 2000). This includes equipment disassembly, rebuild, 

testing, and installation. 

• Annual Costs. During refurbishment, equipment is completely remanufactured. As a result, this 

option is considered a one-time activity, with no annual costs for the lifetime of the project period 

(i.e., 15 years). 

• Cost Savings. It is assumed that all SF6 saved during refurbishment activities represents a cost 

savings, because the facility SF6 purchase and consumption rate will decrease. For this analysis, it 

is assumed that the cost of SF6 is $7 per pound. 

Abatement Options—EU-25+3 and Japan Only 

For each of the following options, cost and emissions reduction potential assumptions are detailed in 

Ecofys (2005). Although these options were developed for EU-25+3 countries, they have also been applied 

to Japan, because Japanese equipment designs and maintenance practices are believed to be similar to 

those in the EU-25+3 (Ecofys, 2005; Yokota et al., 2005). 

• Awareness, Including Training, Monitoring, and Labeling. Awareness includes costs to 

implement training programs for SF6 gas handling during equipment top-up and maintenance. 

Awareness also includes costs to implement SF6 gas management systems, where SF6 inventories, 

purchases, and gas use are monitored. 

• Evacuation of Equipment. Evacuation includes costs associated with attaining a higher level of 

SF6 recovery from closed-pressure equipment (i.e., drawing evacuation pressure from 50 millibar 

[mbar] down to 20 mbar). 

• Repair or Replacement. Ecofys (2005) assumes that 3 percent of closed-pressure systems leak 

more than 2.5 percent per year greater than their design leak rates. Costs are based on 90 percent 

of equipment being repaired, with the remainder replaced. 

• Decommissioning Infrastructure. This includes costs to develop infrastructure to handle end-oflife treatment (both gas and equipment material) of SF6 electrical equipment. 
SECTION IV — INDUSTRIAL PROCESSES • ELECTRIC POWER SYSTEMS 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES IV-195

IV.10.3 Results 

This section discusses the results from the MAC analysis for the world and several regions, for both 

the no-action and technology-adoption scenarios. 

IV.10.3.1 Data Tables and Graphs 

Based on the trends described above, the USEPA developed MACs for several regions. Tables 10-3 

through 10-8 provide a summary of the potential emissions reduction opportunities and associated costs 

for these regions in 2010 and 2020 for the no-action and technology-adoption baselines. The costs to 

reduce 1 tCO2eq are presented for a discount rate of 10 percent and a tax rate of 40 percent. 

Table 10-3: Emissions Reductions in 2010 and Breakeven Costs ($/tCO2eq) for Electric Power Systems at a 

10% Discount Rate, 40% Tax Rate (MtCO2eq)—No-Action Baseline 

2010 

Country/Region $0 $15 $30 $45 $60 >$60 

Africa 1.00 1.03 1.03 1.03 1.03 1.03 

Annex I 12.23 14.99 15.00 15.00 15.04 15.04 

Australia/New Zealand 0.41 0.48 0.48 0.48 0.48 0.48 

Brazil 0.79 0.93 0.93 0.93 0.93 0.93 

China 4.99 5.13 5.13 5.13 5.13 5.13 

Eastern Europe 0.29 0.41 0.41 0.41 0.41 0.41 

EU-15 0.00 0.66 0.67 0.67 0.70 0.70 

India 1.34 1.38 1.38 1.38 1.38 1.38 

Japan 0.00 0.15 0.15 0.15 0.16 0.16 

Mexico 0.49 0.57 0.57 0.57 0.57 0.57 

Non-OECD Annex I 2.15 2.22 2.22 2.22 2.22 2.22 

OECD 11.25 14.14 14.15 14.15 14.19 14.19 

Russian Federation 1.60 1.64 1.64 1.64 1.64 1.64 

South & SE Asia 1.22 1.37 1.37 1.37 1.37 1.37 

United States 8.57 10.05 10.05 10.05 10.05 10.05 

World Total 25.53 29.24 29.26 29.26 29.30 29.30 

EU-15 = European Union; OECD = The Organisation for Economic Co-operation and Development.
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IV-196 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

Table 10-4: Emissions Reductions in 2020 and Breakeven Costs ($/tCO2eq) for Electric Power Systems at 

10% Discount Rate, 40% Tax Rate (MtCO2eq)—No-Action Baseline 

2020 

Country/Region $0 $15 $30 $45 $60 >$60 

Africa 1.40 1.45 1.45 1.45 1.45 1.45 

Annex I 12.85 16.11 16.12 16.12 16.16 16.16 

Australia/New Zealand 0.41 0.48 0.48 0.48 0.48 0.48 

Brazil 1.18 1.38 1.38 1.38 1.38 1.38 

China 8.29 8.52 8.52 8.52 8.52 8.52 

Eastern Europe 0.29 0.45 0.45 0.45 0.46 0.46 

EU-15 0.00 0.95 0.95 0.95 0.98 0.98 

India 1.92 1.97 1.97 1.97 1.97 1.97 

Japan 0.00 0.21 0.21 0.21 0.22 0.22 

Mexico 0.76 0.89 0.89 0.89 0.89 0.89 

Non-OECD Annex I 2.15 2.22 2.22 2.22 2.22 2.22 

OECD 12.33 15.80 15.80 15.80 15.84 15.84 

Russian Federation 1.60 1.64 1.64 1.64 1.64 1.64 

South & SE Asia 1.63 1.82 1.82 1.82 1.82 1.82 

United States 9.18 10.78 10.78 10.78 10.78 10.78 

World Total 32.69 37.32 37.33 37.33 37.36 37.36 

EU-15 = European Union; OECD = The Organisation for Economic Co-operation and Development. 

Table 10-5: Emissions Reductions in 2010 and Breakeven Costs ($/tCO2eq) for Electric Power Systems at 

10% Discount Rate, 40% Tax Rate (MtCO2eq)—Technology-Adoption Baseline 

2010 

Country/Region $0 $15 $30 $45 $60 >$60 

Africa 1.00 1.03 1.03 1.03 1.03 1.03 

Annex I 8.15 9.24 9.24 9.24 9.24 9.24 

Australia/New Zealand 0.41 0.48 0.48 0.48 0.48 0.48 

Brazil 0.79 0.93 0.93 0.93 0.93 0.93 

China 4.99 5.13 5.13 5.13 5.13 5.13 

Eastern Europe 0.29 0.30 0.30 0.30 0.30 0.30 

EU-15 0.00 0.00 0.00 0.00 0.00 0.00 

India 1.34 1.38 1.38 1.38 1.38 1.38 

Japan 0.00 0.00 0.00 0.00 0.00 0.00 

Mexico 0.49 0.57 0.57 0.57 0.57 0.57 

Non-OECD Annex I 2.15 2.20 2.20 2.20 2.20 2.20 

OECD 7.17 8.41 8.41 8.41 8.41 8.41 

Russian Federation 1.60 1.64 1.64 1.64 1.64 1.64 

South & SE Asia 1.22 1.37 1.37 1.37 1.37 1.37 

United States 4.48 5.25 5.25 5.25 5.25 5.25 

World Total 21.44 23.50 23.50 23.50 23.50 23.50 

EU-15 = European Union; OECD = The Organisation for Economic Co-operation and Development. 
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GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES IV-197

Table 10-6: Emissions Reductions in 2020 and Breakeven Costs ($/tCO2eq) for Electric Power Systems at 

10% Discount Rate, 40% Tax Rate (MtCO2eq)—Technology-Adoption Baseline 

2020 

Country/Region $0 $15 $30 $45 $60 >$60 

Africa 1.40 1.45 1.45 1.45 1.45 1.45 

Annex I 3.67 7.68 7.68 7.68 7.68 7.68 

Australia/New Zealand 0.41 0.48 0.48 0.48 0.48 0.48 

Brazil 1.18 1.38 1.38 1.38 1.38 1.38 

China 8.29 8.52 8.52 8.52 8.52 8.52 

Eastern Europe 0.29 0.30 0.30 0.30 0.30 0.30 

EU-15 0.00 0.00 0.00 0.00 0.00 0.00 

India 1.92 1.97 1.97 1.97 1.97 1.97 

Japan 0.00 0.00 0.00 0.00 0.00 0.00 

Mexico 0.76 0.89 0.89 0.89 0.89 0.89 

Non-OECD Annex I 2.15 2.20 2.20 2.20 2.20 2.20 

OECD 3.15 7.38 7.38 7.38 7.38 7.38 

Russian Federation 1.60 1.64 1.64 1.64 1.64 1.64 

South & SE Asia 1.63 1.82 1.82 1.82 1.82 1.82 

United States 0.00 3.69 3.69 3.69 3.69 3.69 

World Total 23.51 28.88 28.88 28.88 28.88 28.88 

EU-15 = European Union; OECD = The Organisation for Economic Co-operation and Development. 

Table 10-7: Emissions Reduction and Costs in 2020—No-Action Baseline 

Cost (2000$/tCO2eq) 

DR=10%, TR=40% 

Reduction Option Low High 

Emissions 

Reduction of 

Option 

(MtCO2eq) 

Reduction 

from 2020 

Baseline 

(%) 

Running 

Sum of 

Reductions 

(MtCO2eq) 

Cumulative 

Reduction 

from 2020 

Baseline 

(%) 

Recycling –$0.61 –$0.09 30.65 46.6% 30.65 46.6% 

Decommissioning $1.47 $1.47 1.04 1.6% 31.69 48.2% 

Awareness/training $2.04 $2.04 0.32 0.5% 32.01 48.7% 

Leak detection –$0.56 $2.68 4.38 6.7% 36.39 55.3% 

Refurbishment $5.01 $5.01 0.93 1.4% 37.32 56.7% 

Evacuation $27.28 $27.28 0.01 0.0% 37.33 56.8% 

Repair and replacement $45.51 $45.51 0.04 0.1% 37.36 56.8% 
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IV-198 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

Table 10-8: Emissions Reduction and Costs in 2020—Technology-Adoption Baseline 

Cost (2000$/tCO2eq) 

DR=10%, TR=40% 

Reduction Option Low High 

Emissions 

Reduction of 

Option 

(MtCO2eq) 

Reduction 

from 2020 

Baseline 

(%) 

Running 

Sum of 

Reductions 

(MtCO2eq) 

Cumulative 

Reduction 

from 2020 

Baseline 

(%) 

Recycling –$0.61 $0.10 24.61 42.8% 24.61 42.8% 

Decommissioning $1.47 $1.47 0.00 0.0% 24.61 42.8% 

Awareness/training $2.04 $2.04 0.00 0.0% 24.61 42.8% 

Leak detection –$0.56 $2.68 3.17 5.5% 27.78 48.3% 

Refurbishment $5.01 $5.01 1.10 1.9% 28.88 50.2% 

Evacuation $27.28 $27.28 0.00 0.0% 28.88 50.2% 

Repair and replacement $45.51 $45.51 0.00 0.0% 28.88 50.2% 

IV.10.3.2 Global and Regional MACs and Analysis 

This section discusses the results from the MAC analysis of the world and selected countries and 

regions, including China, Japan, the United States, the EU-15, other OECD, and the rest of the world. 

Figure 10-3 presents the 2010 and 2020 global technology-adoption and no-action MACs for electric 

power systems. For the no-action MACs, significant reductions (comprising more than 48 percent of the 

baseline emissions from this sector) are achievable below $0/tCO2eq in 2010 and 2020. These reductions 

occur through the implementation of SF6 recycling and LDAR options in most countries, except EU-25+3 

and Japan. For the latter countries, decommissioning and awareness/training reduce approximately 2 

percent of global baseline emissions, with both options being implemented below $2/tCO2eq. 

Figure 10-3: 2010 and 2020 Global Technology-Adoption and No-Action MACs for Electric Power 

Systems 
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GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES IV-199

In the technology-adoption MACs, no reductions are available in EU-25+3 and Japan in 2010 and 

2020, because mitigation technologies are assumed to be fully implemented in the baselines of these 

countries. For the remaining countries, more than 40 percent of baseline emissions can be reduced for less 

than $0/tCO2eq through SF6 recycling and LDAR measures. An additional 10 percent of baseline 

emissions can be reduced through $5/tCO2eq. Most of these reductions result from SF6 recycling and 

LDAR in developed regions, such as the United States, and the implementation of refurbishment in all 

countries. The rightward shift in technology-adoption and no-action MACs between 2010 and 2020 

reflects increasing emissions from electric grid infrastructure growth, specifically in developing country 

regions, such as China, Latin America, and Africa. In developed countries, such as the United States, EU25+3, and Japan, voluntary and mandatory emissions reduction programs reduce both baseline emissions 

and the reductions available in the technology-adoption MACs. (As noted above, emissions reductions in 

the technology-adoption baseline actually exhaust the available reductions in Europe and Japan, leaving 

no reductions in the technology-adoption MACs for these regions.) In the no-action MACs, however, it is 

assumed that additional voluntary measures will not be implemented after 2003; consequently, U.S. 

emissions increase while emissions from the EU-25+3 and Japan remain constant between 2010 and 2020, 

reflecting the stabilization of European and Japanese SF6 banks. 

Figures 10-4 and 10-5 present 2010 and 2020 technology-adoption MACs for China, Japan, the United 

States, the EU-15, other OECD, and the rest of the world. These figures show the regional contributions to 

the global trends described above. As noted above, EU-25+3 and Japan offer no emissions reduction 

opportunities in 2010 or 2020, because it is assumed that all mitigation measures, such as 

awareness/training, decommissioning, evacuation, and repair and replacement, are implemented in their 

baselines. For all other countries, SF6 recycling offers the opportunity for significant emissions reductions 

at low carbon cost (i.e., less than or equal to $0.10/tCO2eq). LDAR offers reductions at somewhat higher 

costs ranging from about –$0.56/tCO2eq to $2.68/tCO2eq. LDAR costs have a large labor component 

compared with the recycling option. Consequently, abatement costs are higher in countries where labor 

costs are high, such as the United States, Australia, and Canada, but are very low in other regions, such as 

China, Latin America, and Africa. The pronounced “elbows” in the curves for most regions are indicative 

of the lower emissions reduction potential and higher abatement costs offered by LDAR and 

refurbishment, compared with recycling. 

In 2020, the MACs for all countries and regions have a similar profile to 2010, where SF6 recycling is 

followed by LDAR and refurbishment. However, for some countries and regions, there are minor shifts in 

the curves, specifically those for developing economies, such as China, other OECD, and the rest of the 

world. This shift reflects the potential for increased emissions reductions as electric transmission and 

distribution grids expand and associated SF6 emissions increase to accommodate growing commercial 

and residential energy needs. In comparison, for the United States, the 2020 MAC shifts left as emissions 

available for abatement decrease because of the continuing success of domestic voluntary programs. 

IV.10.3.3 Uncertainties and Limitations 

In developing these estimates of emissions, reductions, and costs, the USEPA made use of multiple 

international data sets and IPCC guidance on estimating emissions from this source. Nevertheless, this 

analysis is subject to a number of uncertainties that affect both global and country-specific estimates of 

emissions, reductions, and costs, particularly estimates for regions other than the United States, Japan, 

and the EU-25+3. 
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IV-200 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

Figure 10-4: 2010 Regional Technology-Adoption MACs for Electric Power Systems 

EU-15 = European Union; OECD = The Organisation for Economic Co-operation and Development. 

Figure 10-5: 2020 Regional Technology-Adoption MACs for Electric Power Systems 

EU-15 = European Union; OECD = The Organisation for Economic Co-operation and Development. 

SF6 Emissions from Electric Power Systems 

Although emissions from the United States, EU-25+3, and Japan are based on bottom-up evaluations 

of emissions rates and SF6 banks in equipment, remaining country-specific estimates are based on 

apportioning RAND survey data (Smythe, 2004) using net electricity consumption statistics. The 

relationship between emissions and electricity consumption varies between regions and over time, 

particularly as countries begin to adopt emission-reducing practices and technologies. Additional 

uncertainties associated with this approach are described in detail in the USEPA (2006) report Global 

Anthropogenic Non-CO2 Greenhouse Gas Emissions: 1990–2020. These uncertainties affect both the global 

total and the country-by-country apportionment of that total. 
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GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES IV-201

Emissions Apportionment/Market Penetration/Reduction Efficiency for All Regions, Except 

EU-25+3 and Japan 

• This analysis is based on the assumption that 67 percent of emissions are attributable to the 

failure to recycle during maintenance and disposal, while 33 percent of emissions are due to 

equipment leakage. The basis for this assumption is a study performed by CIGRE and reported 

by O’Connell et al. (2002). There is very limited information on the apportionment of emissions 

between handling and leakage losses; consequently, this is a potential source of uncertainty. 

• This analysis assumes emissions are due to leakage and failure to recycle only; however, losses 

due to improper handling of SF6 gas may also contribute to baseline emissions. Because of limited 

information, this potential emissions source is not fully addressed in this analysis. 

• Estimates of current market penetration are based on communications with U.S.-based industry 

experts. These estimates are assumed to apply to all global regions; however, it is possible that 

the current 80 percent penetration estimate may be too high for some regions, especially 

developing countries. For example, it is possible that developing countries may not have the 

resources to implement recycling and LDAR to the levels assumed in this analysis. If market 

penetration is lower than assumed, the potential for emissions reduction from these countries 

will be higher. 

• For LDAR, reduction efficiency is assumed to be 50 percent; this is an average number that 

accounts for varying degrees of LDAR success. However, it is technically possible, with current 

practices (e.g., laser leak detection and new sealant technology) to achieve reductions that are 

closer to 100 percent. 

• For refurbishment, reduction efficiency is assumed to be 95 percent. As with LDAR, it is 

technically feasible to achieve reductions of 100 percent; however, the current estimate assumes 

varying degrees of refurbishment success. 

Emissions Apportionment/Market Penetration/Reduction Efficiency for EU-25+3 and Japan 

Only 

This analysis uses cost and emissions reduction potentials developed for EU-25+3 countries (Ecofys, 

2005). The same costs and emissions reduction potentials have been applied to Japan on the assumption 

that Japan and Europe have similar electric transmission and distribution infrastructures and 

maintenance practices. Because there are likely to be some differences in the general age and type of 

equipment used, as well as in the current level of implementation of abatement options, this assumption 

is a potential source for uncertainty in the MACs. Additional uncertainties associated with the specific 

options used for EU-25+3 and Japan are detailed in Ecofys (2005). 

Estimation of Annual Cost 

• For recycling and LDAR, marginal labor cost estimates depend on average recycling rates (64 and 

22 pounds per hour) and the average size of a leak (25 pounds per year per leak), respectively. 

Both of these estimates may vary significantly and are, consequently, a source of uncertainty in 

the MACs. In developing recycling costs, it is assumed that 61 percent of emissions are abatable 

through increased market penetration, while 31 percent are abatable through “deeper” recovery 

(i.e., 80 percent to 95 percent). The apportionment of reductions to these two types of recovery is 

important because it affects the average recovery rate, and therefore labor costs, assumed in the 

analysis. However, this apportionment depends on the market penetration, reduction efficiency, 

and theoretical applicability assumed for recycling, all of which are subject to uncertainty. 
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IV-202 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

• For refurbishment, costs are based on a circuit breaker with a nameplate capacity of 1,500 pounds 

and an emissions rate of 20 percent; however, depending on the equipment (location, age, and 

type), these values may vary significantly, adding a source of uncertainty in the MACs. 

• Data on leak rates are limited, but a recent USEPA study looking at new equipment leak rates 

may shed some light on this emissions source. 

• Adjusting Costs for Specific Domestic Situations: The annual and capital costs associated with 

implementing recycling and LDAR options are based on U.S. information. Although adjustments 

for annual costs are included to account for differing country-specific labor costs, there remains a 

potential source of uncertainty associated with recycling capital costs. Specifically, other 

countries may be faced with higher costs from transportation and tariffs associated with 

purchasing the technology abroad, or they may be faced with lower costs from domestic 

production of these technologies. Also, it is assumed that LDAR capital costs are minimal; 

however, repair costs can range from $10 to $100,000. Consequently, current MACs may 

underestimate the dollars per tCO2eq associated with LDAR. 

Country-Specific Tax and Discount Rates 

A single tax rate is applied to the electric power sector in all countries to calculate the annual benefits 

of each technology. Tax rates can vary across countries and, in the case of developing countries, taxes 

may be less applicable. Similarly, the discount rate may vary by country. Improving the level of countryspecific detail will help analysts more accurately calculate benefits and hence breakeven prices. 

IV.10.4 References 

Cryoquip. 2003. SF6 Gas Recycling Carts: Cart Selection. Available at <http://www.cryoquip.com/>. 

Dilo. 2003. SF6 Recovery Equipment. Available at <http://www.dilo.com/recovery.html>. 

Ecofys. 2005. Reductions of SF6 Emissions from High and Medium Voltage Electrical Equipment in Europe. Final 

Report to Capiel. 

Ellerton, K. 1997. Recent Developments and the Outlook for Global SF6. AlliedSignal, Inc. 

ICF. 2000. Personal Communication with Jam es D .M cCreary.A m erican Electric Pow er.

ICF. 2001. Personal Communication with Eric Campbell. Dilo Company, Inc.

McCracken, G.A., R. Christiansen, and M. Turpin. 2000. The Environmental Benefits of Remanufacturing: 

Beyond SF6 Emissions Reduction. International Conference on SF6 and the Environment: Emissions 

Reduction Technologies, November 2-3, San Diego, CA. 

McRae, T. 2000. GasVue and the Magnesium Industry: Advanced SF6 Leak Detection. Presented at the 

Conference on SF6 and the Environment: Emissions Reduction Strategies, November 1–2, San Diego, 

CA. 

O’Connell, P., F. Heil, J. Henriot, G. Mauthe, H. Morrison, L. Neimeyer, M. Pittroff, R. Probst, and J.P. 

Tailebois. 2002. SF6 in the Electric Industry, Status 2000. CIGRE. 

Smythe, K. December 1–3, 2004. Trends in SF6 Sales and End-Use Applications: 1961–2003. Presented at the 

International Conference on SF6 and the Environment: Emissions Reduction Technologies, Scottsdale, 

AZ. 

U.S. Energy Information Administration (USEIA). 2002. International Energy Outlook 2002. Washington, 

DC: U.S. Department of Energy, Energy Information Administration, Office of Integrated Analysis 

and Forecasting. 

U.S. Environmental Protection Agency (USEPA). 2005. Inventory of U.S. Greenhouse Gas Emissions and 

Sinks: 1990–2003. Washington, DC: USEPA. 

U.S. Environmental Protection Agency (USEPA). 2006. Global Anthropogenic Non-CO2 Greenhouse Gas 

Emissions: 1990–2020. Washington, DC: USEPA. 
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GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES IV-203

Yokota, T., K. Yokotsu, K., Kawakita, H. Yonezawa, T. Sakai, and T. Yamagiwa. 2005. Recent Practice for 

Huge Reduction of SF6 Gas Emissions from GIS&GCB in Japan. Presented at the CIGRE SC A3 & B3 Joint 

Colloquium in Tokyo. 
SECTION IV — INDUSTRIAL PROCESSES • ELECTRIC POWER SYSTEMS 

IV-204 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 
SECTION IV — INDUSTRIAL PROCESSES • MAGNESIUM PRODUCTION 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES IV-205

IV.11 SF6 Emissions from Magnesium (Mg) Production 

IV.11.1 Source Description 

he Mg metal production and casting industry uses SF6 as a cover gas to prevent the 

spontaneous combustion of molten Mg in the presence of air. The industry originally adopted 

SF6 to replace SO2 as the primary cover gas. Although recent studies indicate some destruction 

of SF6 in its use as a cover gas (Bartos et al., 2003), this analysis follows current IPCC guidelines (IPCC, 

2000), which assume that all SF6 used is emitted into the atmosphere. Fugitive SF6 emissions may occur in 

various phases of magnesium manufacture and casting, such as primary production, die-casting, and 

recycling-based production. Additional processes that may use SF6 include sand and gravity casting; 

however, these are assumed to be minor sources and are not included in the analysis. Baseline emissions 

estimates under both a technology-adoption and a no-action baseline scenario are presented in 

Tables 11-1 and 11-2.

IV.11.1.1 Technology-Adoption Baseline 

Under the Technology-Adoption Baseline scenario, it is assumed that Mg producers and processors 

outside of China will introduce technologies and practices aimed at reducing SF6 emissions. Specific 

technologies include alternative cover gases, such as Novec 612 (a patented fluoroketone produced by 

3M) and HFC-134a, and better containment and pollution control systems, which enable the use of SO2

without the industrial hygiene and odor problems of the past. Under this scenario, International 

Magnesium Association (IMA) members, who account for 80 percent of the global Mg industry outside of 

China (IMA, 2003), will meet a target of eliminating the use of SF6 by 2011. 

Figure 11-1 presents total SF6 emissions from the Mg industry under the technology-adoption 

scenario from 1990 through 2020. As shown in the graph, total emissions from the Mg industry remained 

fairly constant through the mid-1990s, but then fell sharply to 9 MtCO2eq in 2000. The drop in global 

emissions between 1995 and 2000 is the result of both facility closures in the United States and global 

reductions in SF6 usage through more efficient operational practices. The latter is a response to increasing 

SF6 gas prices and a growing environmental awareness of its high GWP. Additional plant closings have 

been reported in Norway, Canada, and Japan, which have added to the decline in the share of global 

emissions generated by OECD90+ through 2020. This lost production has been primarily absorbed by 

China, which has dominated the foreign market with low-cost exports. 

From 2000 through 2010, the steep decline in global SF6 emissions is attributable to the adoption of 

alternative cover-gases; either SO2 or Novec 612 and HFC-134a. By the end of 2010, in accordance with 

the IMA goal, all countries except China are assumed to have eliminated the use of SF6 from Mg 

production and casting operations. 

For China, it is assumed that some primary production and all casting facilities will use SF6 to 

produce high-quality magnesium and products for the world market. Because Chinese producers and 

processors are not IMA members and have not committed to the IMA emissions reduction goal, their SF6

use is assumed to continue through 2020. Consequently, from 2010 through 2020, the increase in global 

emissions from 4 to 5 MtCO2eq will be driven entirely by China, whose emissions are expected to 

increase from 2 to 4 MtCO2eq. In 2020, the China/CPA share of global emissions is expected to be 77 

percent, compared with 0.3 percent in 1990. OECD’s share of global emissions is projected to decrease 

from 77 percent in 1990 to 21 percent in 2020 because of adoption of the IMA goal and reduction in 

production capacity. In 2020, U.S. emissions account for a majority of OECD emissions. These emissions 

are due to some U.S. casting and recycling firms that have not committed to phaseout use of SF6 (USEPA, 

2005). 

T 
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IV-206 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

Table 11-1: Total SF6 Emissions from Mg Manufacturing (MtCO2eq)—No-Action Baseline 

Country/Region 2000 2010 2020 

Africa 0.0 0.0 0.0 

Annex I 7.4 8.3 11.3 

Australia/New Zealand 0.0 0.0 0.0 

Brazil 0.2 0.5 0.7 

China 0.2 1.7 3.7 

Eastern Europe 0.0 0.0 0.0 

EU-15 0.5 1.0 1.6 

India 0.0 0.0 0.0 

Japan 0.2 0.1 0.2 

Mexico 0.0 0.0 0.0 

Non-OECD Annex I 0.9 1.5 1.8 

OECD 6.5 6.8 9.5 

Russian Federation 0.9 1.2 1.5 

South & SE Asia 0.0 0.0 0.0 

United States 3.2 4.6 6.4 

World Total 8.8 12.1 18.1 

EU-15 = European Union; OECD = Organisation for Economic Co-operation and Development. 

Table 11-2: Total SF6 Emissions from Mg Manufacturing (MtCO2eq)—Technology-Adoption Baseline 

Country/Region 2000 2010 2020 

Africa 0.0 0.0 0.0 

Annex I 7.4 1.7 1.1 

Australia/New Zealand 0.0 0.0 0.0 

Brazil 0.2 0.1 0.0 

China 0.2 1.7 3.7 

Eastern Europe 0.0 0.0 0.0 

EU-15 0.5 0.1 0.0 

India 0.0 0.0 0.0 

Japan 0.2 0.0 0.0 

Mexico 0.0 0.0 0.0 

Non-OECD Annex I 0.9 0.2 0.0 

OECD 6.5 1.5 1.0 

Russian Federation 0.9 0.1 0.0 

South & SE Asia 0.0 0.0 0.0 

United States 3.2 1.2 1.0 

World Total 8.8 3.6 4.8 

EU-15 = European Union; OECD = Organisation for Economic Co-operation and Development. 
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GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES IV-207

Figure 11-1: SF6 Emissions from Mg Manufacturing Based on a Technology-Adoption Scenario—1990–

2020 (MtCO2eq) 

CPA = Centrally Planned Asia; EU-25 = European Union; Non-EU FSU = non-European Union Former Soviet Union countries; OECD90+ = 

Organisation for Economic Co-operation and Development; S&E Asia = Southeast Asia. 

IV.11.1.2 No-Action Baseline 

Under the no-action baseline scenario, it is assumed that Mg producers will take no action to reduce 

their emissions; as a result, emissions projections do not reflect anticipated technology adoptions and/or 

preventive maintenance steps taken to reduce emissions. 

Figure 11-2 presents total SF6 emissions from Mg production under the no-action scenario from 1990 

through 2020. The trends from 1990 through 2000 are the same as those discussed in the technologyadoption baseline. From 2000 through 2020, global emissions in this scenario double to 19 MtCO2 as the 

industry experiences strong growth, particularly in the die-casting and recycling segments. China/CPA 

registers particularly significant emissions growth between 1990 and 2020, increasing its global share of 

emissions from 0.3 percent in 1990 to approximately 21 percent in 2020. For OECD, emissions in this 

scenario are assumed to continue to drop between 2000 and 2005 because of facility closures in Canada 

stemming from pricing pressure from Chinese imports. However, by 2020, OECD emissions are expected 

to return to 1990 levels as production levels increase. Because global emissions will increase by more than 

50 percent during this period, the OECD share of global emissions will fall from 77 percent in 1990 to 53 

percent in 2020. 

Increasing Chinese primary production and die-casting is being fueled by local and foreign 

investment, which has driven the overall increase in China/CPA’s share of global emissions. This trend in 

emissions growth is amplified by the assumption that 10 percent of their primary production utilized SF6

as the cover-gas mechanism. 
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IV-208 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

Figure 11-2: SF6 Emissions from Mg Manufacturing Based on a No-Action Scenario—1990–2020 

(MtCO2eq) 

CPA = Centrally Planned Asia; EU-25 = European Union; Non-EU FSU = non-European Union Former Soviet Union countries; OECD90+ = 

Organisation for Economic Co-operation and Development; S&E Asia = Southeast Asia. 

IV.11.2 Cost of SF6 Emissions Reduction from Mg Production and 

Processing Operations 

IV.11.2.1 Abatement Options 

Two potential abatement options are available for reducing SF6 emissions from Mg production and 

processing operations. These technical measures are 

• replacement with alternate cover gas—SO2 and 

• replacement with alternate cover gas—fluorinated gases. 

The remainder of Section IV.11.2 provides an overview of each abatement option and details the cost 

and reduction assumptions. 

Replacement with Alternate Cover Gas—Sulfur Dioxide 

In the past, SO2 has been used as a cover gas in Mg production and processing activities. However, 

because of toxicity, odor, and corrosivity concerns, SO2 use was discontinued in most countries. Current 

SO2 technology research aims to improve process feed systems and control technology, as well as to 

address toxicity and odor issues with improved containment and pollution control systems (Environment 

Canada, 1998). The use of SO2 has the potential to reduce SF6 emissions by 100 percent, because a 

complete replacement of the cover gas system is involved. It is assumed to be applicable, with limited 

exceptions (e.g., direct-chill casting), to all global Mg producers and processors. For all countries except 

China, the maximum market penetration for this option is assumed to be 50 percent of the emissions of 
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GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES IV-209

SF6 in the technology-adoption baseline. For China, where SO2 replacement is the only option to be 

implemented, maximum market penetration is assumed to be 100 percent. 

Cost and Emissions Reduction Analysis 

• Capital/Upfront Costs. The assumed country-level capital spending requirements for the 

implementation of an SO2 system were based on cost information developed for the Canadian 

Mg production and processing system (Environment Canada, 1998). For Canada, with two 

primary producers and five casters, the costs to install SO2 cover gas systems with containment 

and pollution control systems were estimated at approximately $10 million. These capital costs 

were divided by estimated Canadian emissions from Mg production and processing in 2000. The 

resulting capital cost per tCO2eq, $5.73 per tCO2eq, was then applied to the rest of the world. 

• Annual Costs. Because of potential employee turnover, it is assumed that costs associated with 

worker training will occur on an annual basis at a cost of $50,000 per facility. Assuming seven 

facilities were operating in Canada in 2000, total annual costs of $350,000 were divided by 

estimated Canadian emissions from Mg production and processing in 2000, adjusted to account 

for the variation of labor rates across countries and applied to the rest of the world. 

• Cost Savings. The price of SO2 is significantly lower than that of SF6. Using industry-based 

estimates, the installation of SO2 technology will reduce gas purchase costs by approximately 90 

percent (ICF, 1998). It is assumed that all primary producers, casters, and recyclers use similar 

amounts of SF6. 

Replacement with Alternate Cover Gas—Fluorinated Gases 

Research has yielded a number of candidate fluorinated compounds, such as Novec 612 and HFC134a, as cover gas substitutes for SF6 (Mibrath, 2002; Rickets, 2002; Hillis, 2002). While fluorinated gases 

have an advantage over SO2 because they have potentially fewer associated health, odor, and corrosive 

impacts, some current candidate gases still have GWPs. However, these GWPs are well below that of SF6, 

and within a few years, fluorinated gases will likely provide a functional replacement for SF6. It is 

estimated that where this technology is implemented, GWP-weighted cover gas emissions could be 

reduced by 95 percent to essentially 100 percent. (This analysis uses an average reduction of 97 percent.) 

This option is assumed to be applicable to all countries that produce and/or process Mg, except China, 

where only SO2 replacement is assumed to be implemented. For those countries in which the option is 

implemented, the maximum market penetration is assumed to be 50 percent of the baseline emissions of 

SF6 in the technology-adoption scenario. 

Cost and Emissions Reduction Analysis 

• Capital/Upfront Costs. The capital costs associated with adopting the various fluorinated gases 

are likely to vary, with some gases requiring relatively little retrofitting of the SF6 cover gas 

system and others requiring more. This analysis conservatively assumes that, on average, the 

capital costs of replacing SF6 with fluorinated gases will be the same as the capital costs of 

replacing SF6 with SO2, which include costs for developing a special distributed feed system and 

process and implementing pollution control systems. 

• Annual Costs. Costs are conservatively assumed to be similar to those required for SO2

replacement. 

• Cost Savings. It is assumed that alternate fluorinated gases will cost the same as SF6; hence, no 

cost savings will be realized with a switch to this technology. 
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IV-210 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

IV.11.3 Results 

This section discusses the result from the MAC analysis for the world and various regions for the noaction and technology-adoption scenarios. 

IV.11.3.1 Data Tables and Graphs 

Tables 11-3 through 11-8 provide a summary of the potential emissions reduction opportunities and 

associated costs for the world and various regions in 2010 and 2020 for the no-action and technologyadoption baselines. The costs to reduce 1 tCO2eq are presented for a discount rate of 10 percent and a tax 

rate of 40 percent. 

Table 11-3: Emissions Reductions in 2010 and Breakeven Costs ($/tCO2eq) for Mg Production at 10% 

Discount Rate, 40% Tax Rate (MtCO2eq)—No-Action Baseline 

2010 

Country/Region $0 $15 $30 $45 $60 >$60 

Africa 0.00 0.00 0.00 0.00 0.00 0.00 

Annex I 0.00 8.13 8.13 8.13 8.13 8.13 

Australia/New Zealand 0.00 0.00 0.00 0.00 0.00 0.00 

Brazil 0.00 0.47 0.47 0.47 0.47 0.47 

China 0.00 1.65 1.65 1.65 1.65 1.65 

Eastern Europe 0.00 0.00 0.00 0.00 0.00 0.00 

EU-15 0.00 1.01 1.01 1.01 1.01 1.01 

India 0.00 0.00 0.00 0.00 0.00 0.00 

Japan 0.00 0.11 0.11 0.11 0.11 0.11 

Mexico 0.00 0.00 0.00 0.00 0.00 0.00 

Non-OECD Annex I 0.00 1.43 1.43 1.43 1.43 1.43 

OECD 0.00 6.70 6.70 6.70 6.70 6.70 

Russian Federation 0.00 1.20 1.20 1.20 1.20 1.20 

South & SE Asia 0.00 0.00 0.00 0.00 0.00 0.00 

United States 0.00 4.50 4.50 4.50 4.50 4.50 

World Total 0.00 11.94 11.94 11.94 11.94 11.94 

EU-15 = European Union; OECD = Organisation for Economic Co-operation and Development. 
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GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES IV-211

Table 11-4: Emissions Reductions in 2020 and Breakeven Costs ($/tCO2eq) for Mg Production at 10% 

Discount Rate, 40% Tax Rate (MtCO2eq)—No-Action Baseline 

2020 

Country/Region $0 $15 $30 $45 $60 >$60 

Africa 0.00 0.00 0.00 0.00 0.00 0.00 

Annex I 0.00 11.13 11.13 11.13 11.13 11.13 

Australia/New Zealand 0.00 0.00 0.00 0.00 0.00 0.00 

Brazil 0.00 0.70 0.70 0.70 0.70 0.70 

China 0.00 3.74 3.74 3.74 3.74 3.74 

Eastern Europe 0.00 0.00 0.00 0.00 0.00 0.00 

EU-15 0.00 1.54 1.54 1.54 1.54 1.54 

India 0.00 0.00 0.00 0.00 0.00 0.00 

Japan 0.00 0.18 0.18 0.18 0.18 0.18 

Mexico 0.00 0.00 0.00 0.00 0.00 0.00 

Non-OECD Annex I 0.00 1.78 1.78 1.78 1.78 1.78 

OECD 0.00 9.35 9.35 9.35 9.35 9.35 

Russian Federation 0.00 1.51 1.51 1.51 1.51 1.51 

South & SE Asia 0.00 0.00 0.00 0.00 0.00 0.00 

United States 0.00 6.26 6.26 6.26 6.26 6.26 

World Total 0.00 17.85 17.85 17.85 17.85 17.85 

EU-15 = European Union; OECD = Organisation for Economic Co-operation and Development. 

Table 11-5: Emissions Reductions in 2010 and Breakeven Costs ($/tCO2eq) for Mg Production at 10% 

Discount Rate, 40% Tax Rate (MtCO2eq)—Technology-Adoption Baseline 

2010 

Country/Region $0 $15 $30 $45 $60 >$60 

Africa 0.00 0.00 0.00 0.00 0.00 0.00 

Annex I 0.00 1.54 1.54 1.54 1.54 1.54 

Australia/New Zealand 0.00 0.00 0.00 0.00 0.00 0.00 

Brazil 0.00 0.05 0.05 0.05 0.05 0.05 

China 0.00 1.65 1.65 1.65 1.65 1.65 

Eastern Europe 0.00 0.00 0.00 0.00 0.00 0.00 

EU-15 0.00 0.10 0.10 0.10 0.10 0.10 

India 0.00 0.00 0.00 0.00 0.00 0.00 

Japan 0.00 0.01 0.01 0.01 0.01 0.01 

Mexico 0.00 0.00 0.00 0.00 0.00 0.00 

Non-OECD Annex I 0.00 0.14 0.14 0.14 0.14 0.14 

OECD 0.00 1.39 1.39 1.39 1.39 1.39 

Russian Federation 0.00 0.12 0.12 0.12 0.12 0.12 

South & SE Asia 0.00 0.00 0.00 0.00 0.00 0.00 

United States 0.00 1.17 1.17 1.17 1.17 1.17 

World Total 0.00 3.40 3.40 3.40 3.40 3.40 

EU-15 = European Union; OECD = Organisation for Economic Co-operation and Development. 
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IV-212 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

Table 11-6: Emissions Reductions in 2020 and Breakeven Costs ($/tCO2eq) for Mg Production at 10% 

Discount Rate, 40% Tax Rate (MtCO2eq)—Technology-Adoption Baseline 

2020 

Country/Region $0 $15 $30 $45 $60 >$60 

Africa 0.00 0.00 0.00 0.00 0.00 0.00 

Annex I 0.00 0.90 0.90 0.90 0.90 0.90 

Australia/New Zealand 0.00 0.00 0.00 0.00 0.00 0.00 

Brazil 0.00 0.00 0.00 0.00 0.00 0.00 

China 0.00 3.74 3.74 3.74 3.74 3.74 

Eastern Europe 0.00 0.00 0.00 0.00 0.00 0.00 

EU-15 0.00 0.00 0.00 0.00 0.00 0.00 

India 0.00 0.00 0.00 0.00 0.00 0.00 

Japan 0.00 0.00 0.00 0.00 0.00 0.00 

Mexico 0.00 0.00 0.00 0.00 0.00 0.00 

Non-OECD Annex I 0.00 0.00 0.00 0.00 0.00 0.00 

OECD 0.00 0.90 0.90 0.90 0.90 0.90 

Russian Federation 0.00 0.00 0.00 0.00 0.00 0.00 

South & SE Asia 0.00 0.00 0.00 0.00 0.00 0.00 

United States 0.00 0.90 0.90 0.90 0.90 0.90 

World Total 0.00 4.63 4.63 4.63 4.63 4.63 

EU-15 = European Union; OECD = Organisation for Economic Co-operation and Development. 

Table 11-7: Emissions Reduction and Costs in 2020—No-Action Baseline 

Cost (2000$/tCO2eq) 

DR=10%, TR=40% 

Reduction Option Low High 

Emissions 

Reduction of 

Option 

(MtCO2eq) 

Reduction 

from 2020 

Baseline (%) 

Running 

Sum of 

Reductions 

(MtCO2eq) 

Cumulative 

Reduction 

from 2020 

Baseline (%) 

SO2 replacement $0.53 $0.79 10.90 60.3% 10.90 60.3% 

Fluorinated covergas $1.21 $1.48 6.95 38.5% 17.85 98.8% 

Table 11-8: Emissions Reduction and Costs in 2020—Technology-Adoption Baseline 

Cost (2000$/tCO2eq) 

DR=10%, TR=40% 

Reduction Option Low High 

Emissions 

Reduction of 

Option 

(MtCO2eq) 

Reduction 

from 2020 

Baseline (%) 

Running 

Sum of 

Reductions 

(MtCO2eq) 

Cumulative 

Reduction 

from 2020 

Baseline (%) 

SO2 replacement $0.53 $0.79 4.19 86.6% 4.19 86.6% 

Fluorinated covergas $1.21 $1.48 0.44 9.2% 4.63 95.8% 
SECTION IV — INDUSTRIAL PROCESSES • MAGNESIUM PRODUCTION 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES IV-213

IV.11.3.2 Global and Regional MACs and Analysis 

This section discusses the results from the MAC analysis of the world and selected countries and 

regions, including China, Japan, the United States, EU-15, other OECD, and the rest of the world. 

Figure 11-3 presents the 2010 and 2020 global technology-adoption and no-action MACs for Mg 

production and processing. The technology-adoption MACs reflect the successful achievement of the 

IMA goal to eliminate SF6 use by 2011. Although it is expected that the majority of SF6 use will be 

eliminated by 2011, some use is assumed to continue to occur in the United States and China in 2020. The 

rightward shift in technology-adoption MACs between 2010 and 2020 primarily reflects the continuing 

growth of Chinese primary production and die-casting and their associated use of SF6 as a cover gas. 

Figure 11-3: 2010 and 2020 Global Technology-Adoption and No-Action MACs for Mg Production 

In contrast, the no-action MACs assume that no technology adoptions and/or preventive maintenance 

steps are taken to reduce emissions. Because the SF6 emissions intensities (i.e., SF6 emissions per unit of 

Mg production) for primary, secondary, and casting production are assumed to remain constant between 

2010 and 2020, increasing emissions (reflected by the rightward shift in the 2020 MAC) are driven by 

continuing positive production growth in all regions, particularly the United States and China. 

Figures 11-4 and 11-5 present 2010 and 2020 regional technology-adoption MACs for China, Japan, 

the United States, EU-15, other OECD, and the rest of the world. The 2010 MAC represents potential 

emissions reductions and associated costs for global Mg producers and processors a year before the 

assumed successful adoption of the IMA goal. Consequently, the small reductions associated with EU-15 

countries, Japan, other OECD (e.g., Norway and Canada), and the rest of the world (e.g., Brazil, Taiwan, 

Israel, the Russian Federation, Ukraine, and Kazakhstan) reflect this assumption. In China and the United 

States, some Mg casters and recyclers have not committed to the IMA goal; consequently, significant 

emissions reductions are still achievable through implementation of abatement options. In China, SO2 is 

considered the only abatement option, while in the United States, both SO2 and alternate fluorinated 

gases are assumed to be available. In all regions, SO2 is estimated to be less expensive than fluorinated 

gases such as Novec 612 and HFC-134a. 
SECTION IV — INDUSTRIAL PROCESSES • MAGNESIUM PRODUCTION 

IV-214 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

Figure 11-4: 2010 Regional Technology-Adoption MACs 

EU-15 = European Union; OECD = Organisation for Economic Co-operation and Development. 

Figure 11-5: 2020 Regional Technology-Adoption MACs 

EU-15 = European Union; OECD = Organisation for Economic Co-operation and Development. 

In 2020, for the technology-adoption MACs, reductions are only available for the United States and 

China. For all other Mg producing countries, it is assumed that the IMA goal has been successfully 

achieved. In the United States, although abatement costs are the same as in 2010, the curve has shifted to 

the left. This reflects the fact that primary production and a majority of casting companies in the United 

States have agreed to meet the IMA goal; consequently, the only emissions available for abatement in 

2020 are from the remaining casting and recycling firms that have not committed to phaseout SF6 use. In 

China, carbon costs for SO2 abatement are assumed to be the same as in 2010 ($0.53/tCO2eq); however, the 
SECTION IV — INDUSTRIAL PROCESSES • MAGNESIUM PRODUCTION 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES IV-215

MAC has shifted to the right because of increased use of SF6 during primary production and casting in 

the baseline, which is projected to grow significantly to meet local demand. 

IV.11.3.3 Uncertainties and Limitations 

Uncertainties and limitations persist despite attempts to incorporate all publicly available 

information on international Mg production and processing. Additional information would improve the 

accuracy of the MACs. 

Mg Production and Processing 

Although historical primary production statistics are available for most countries, a source of 

uncertainty is the limited information on historical country-specific secondary and die-casting production 

and Chinese primary production. There is also limited information on country-specific SF6 usage rates 

(i.e., emissions factors); these rates are likely to vary by facility and country because of differing 

operational practices and manufacturing processes. Additionally, the current methodology assumes that 

all SF6 gas used is emitted into the atmosphere; however, recent studies (Bartos et al., 2003; USEPA, 2004) 

indicate that some SF6 degradation may occur (e.g., 10 percent) during magnesium melt protection. As a 

result, current SF6 emissions factors may be higher than actual emissions rates. Improved country-specific 

production-level data and growth projections and SF6 usage rates would improve the baseline emissions 

estimates to which the abatement options are applied. 

IMA SF6 Reduction Goal 

In the technology-adoption baseline, emissions projections assume attainment of the IMA goal, which 

is the elimination by 2011 of SF6 use in Mg production and processing operations in all countries except 

China and the United States where some processors have not committed to the goal. Because there is 

limited information on country-specific implementation of alternate cover gas practices, at the current 

time, it is unclear whether this goal will be achieved. Improved information on country-specific practices 

would improve modeling of the IMA goal. 

Implementation of Alternate Cover Gases 

For most countries, the MACs assume a 50/50 percent market penetration of SO2 and fluorinated 

(Novec 612 and HFC-134a) cover gases. Because of limited information, it is unclear if this is an accurate 

representation of actual future industry application of these technologies. However, because the 

reduction efficiencies for the abatement options are high (i.e., 100 percent for SO2 and an average of 97 

percent for fluorinated gases), the uncertainty in the reduction achieved will be low. Recent USEPA 

studies have noted that both Novec 612 and HFC-134a undergo significant degradation while providing 

melt protection; consequently, reduction efficiencies may be even higher than those currently used (i.e., 

99.9 percent) (USEPA, 2004). 

Costs of Alternative Fluorinated Cover Gases 

The capital costs associated with adopting the various fluorinated gases are likely to vary, with some 

gases requiring relatively little retrofitting of the SF6 cover gas system and others requiring more. This 

analysis conservatively assumes that, on average, the capital costs of replacing SF6 with fluorinated gases 

will be the same as the capital costs of replacing SF6 with SO2, which includes costs for developing a 

special distributed feed system and process and implementing pollution control systems. Not all 

fluorinated gases are likely to require such systems. Thus, in some cases, this analysis probably 

overestimates the costs of adopting alternative fluorinated gases. 
SECTION IV — INDUSTRIAL PROCESSES • MAGNESIUM PRODUCTION 

IV-216 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

Adjusting Costs for Specific Domestic Situations 

The annual and capital costs associated with implementing the SO2 abatement option are based on 

information provided in the Powering GHG Reduction through Technology Advancements report by 

Environment Canada (1998). Although adjustments for annual costs are provided to account for differing 

country-specific labor costs, no adjustments for capital costs are applied. This is a potential source of 

uncertainty because countries other than Canada may be faced with higher costs due to transportation 

and tariffs associated with purchasing the technology from abroad or could be faced with lower costs due 

to domestic production of these technologies. 

Country-Specific Tax and Discount Rates 

A single tax rate is applied to the Mg sector in all countries to calculate the annual benefits of each 

technology; however, tax rates can vary across countries. Similarly, the discount rate may vary by 

country. Improving the level of country-specific detail will help analysts more accurately calculate 

benefits and hence breakeven prices. 

IV.11.4 References 

Bartos S., J. Marks, R. Kantamaneni, and C. Laush. 2003. “Measured SF6 Emissions from Magnesium Die 

Casting Operations.” In Howard A. Kaplan (ed.) Magnesium Technology pp. 23–27. Warrendale, PA: 

Minerals, Metals, & Materials Society. 

Environment Canada. 1998. Powering GHG Reductions through Technology Advancement. Clean Technology 

Advancement Division, Environment Canada. 

Hillis, J. 2002. The International Program to Identify Alternatives to SF6 in Magnesium Melt Protection.

Presented at the International Conference on SF6 and the Environment: Emissions Reduction 

Technologies, November 21-22, San Diego, CA. 

ICF. 1998. Personal communication from Norsk Hydro. 

Intergovernmental Panel on Climate Change (IPCC). 2000. “Good Practice Guidance and Uncertainty 

Management in National Greenhouse Gas Inventories.” Section 3.3. Available at <http://www.ipccnggip.iges.or.jp/public/gp/english/3_Industry.pdf>. 

International Magnesium Association (IMA). 2003. Available at <http://www.climatevision.gov/ 

sectors/Mg/index.html>. 

Mibrath, D. 2002. Development of 3M Novec 612 Magnesium Protection Fluid as a Substitute for SF6 Over 

Molten Magnesium. Presented at the International Conference on SF6 and the Environment: Emissions 

Reduction Technologies, November 21-22, San Diego, CA. 

Ricketts, N. 2002. Environmental Implications of Using HFC-134a as a Replacement for SF6 in the Magnesium 

Industry. Presented at the International Conference on SF6 and the Environment: Emissions Reduction 

Technologies, November 21-22, San Diego, CA. 

U.S. Environmental Protection Agency (USEPA). 2004. Characterization of Cover Gas Emissions from U.S. 

Magnesium Casting. EPA 430-R-04-004. Washington, DC: U.S. Environmental Protection Agency, 

Office of Air and Radiation. 

U.S. Environmental Protection Agency (USEPA). 2006. Global Anthropogenic Non-CO2 Greenhouse Gas 

Emissions: 1990–2020. Washington, DC: USEPA. 
Section IV: Industrial Processes Sector Appendixes 

Appendixes for this section are available for download from the USEPA’s Web site at 

http://www.epa.gov/nonco2/econ-inv/international.html. 

V. Agriculture 
SECTION V — AGRICULTURE • PREFACE 

V-ii GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

Section V presents international emission baselines and marginal abatement curves (MACs) for all 

significant agricultural non-CO2 sources. There are subsections that address emissions and mitigation 

options for croplands, rice cultivation, and livestock. These sources are associated with methane (CH4) 

and nitrous oxide (N2O) emissions, as well as soil carbon. MAC data are focused on percentage reduction 

values from baseline emissions. These data can be downloaded in spreadsheet format from the USEPA’s 

Web site at <http://www.epa.gov/nonco2/econ-inv/international.html>. 

Section V—Agriculture is organized as follows: 

V.1 Introduction and Background 

V.2. Emissions Characterization, Baselines, and Mitigation Scenarios 

V.2.1 Croplands (N2O and soil carbon) 

V.2.2 Rice (CH4, N20 and soil carbon) 

V.2.3 Livestock (CH4 and N20) 

V.3 Results 

V.3.1 Estimating Average Costs and Constructing Abatement Curves 

V.3.2 Croplands 

V.3.3 Rice 

V.3.4 Livestock 

V.3.5 Total Agriculture 

V.3.6 Agricultural Commodity Market Impacts 

V.4 Conclusions 
SECTION V — AGRICULTURE • INTRODUCTION AND BACKGROUND 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES V-1

V.1 Introduction and Background 

Agricultural activities currently generate the largest share, 63 percent, of the world’s anthropogenic 

non-carbon dioxide (non-CO2) emissions (84 percent of nitrous oxide [N2O] and 52 percent of methane 

[CH4]), and make up roughly 15 percent of all anthropogenic greenhouse gas emissions (U.S. 

Environmental Protection Agency [USEPA], 2006; Prentice et al., 2001).1 Agricultural greenhouse gas 

emissions are projected to increase significantly over the next 20 years, especially in Asia, Latin America, 

and Africa, because of increased demand for agricultural products as a result of population growth; 

rising per capita caloric intake; and changing diet preferences, such as an increased consumption of meat 

and dairy products over grains and vegetables (see Food and Agriculture Organization [FAO], 2002). 

Agricultural soil N2O emissions are projected to increase 37 percent by 2020 compared with 2000 levels, 

enteric livestock CH4 emissions are projected to increase 30 percent, manure CH4 and N2O to increase 24 

percent,2 and rice CH4 to increase 22 percent (USEPA, 2006). 

The agricultural sector presents unique challenges to developing greenhouse gas mitigation cost 

estimates at regional and international scales. First, there is a high degree of spatial and temporal 

heterogeneity in biophysical and management conditions and thus in resulting greenhouse gas emissions, 

which are rarely directly monitored. This fact makes it challenging to extrapolate the greenhouse gas and 

cost implications of farm-level mitigation analyses, the scale at which much of the literature on this 

subject is found. Any large-scale mitigation analysis should emphasize the broad trends and direction 

and magnitude of changes, which requires some trade-off in accuracy for very small spatial (e.g., 

individual farms) and temporal (e.g., days and seasons) scales. Second, there is a paucity of regional cost 

data from which one can estimate the implications of implementing greenhouse gas mitigation practices, 

in terms of changes in inputs, revenue, and labor. Third, estimating the expected level of adoption of the 

mitigation options in response to financial incentives (e.g., carbon price) or, alternatively, in response to 

extension services with greenhouse gas reduction objectives, is difficult given the information and 

cultural barriers to adoption in different regions. 

Nevertheless, agricultural net greenhouse gas and non-CO2 mitigation analyses have been developed 

for several countries and the world. Some analyses include a relatively comprehensive set of greenhouse 

gas mitigation options with a dynamic economic and biophysical representation of the agricultural and 

forest sectors (see USEPA [2005a] for the United States). Others target individual agricultural emissions 

sources with static, engineering mitigation estimation methods (see Kroeze and Mosier [1999] for global 

cropland N2O and enteric CH4 emissions and Reimer and Freund [1999] for global rice emissions; see also 

Table 3.27 in Moomaw et al. [2001] of IPCC Working Group III). The USEPA supported the development 

of global mitigation estimates for cropland N2O, livestock enteric and manure CH4, and rice CH4

(DeAngelo et al., 2006) that were then incorporated into the Energy Modeling Forum-21 (EMF-21) study 

of global multigas mitigation options (van Vuuren et al. [2006]). This report improves on the agricultural 

analysis conducted for EMF-21 in a number of areas. 

 

1

 This value compares the International Panel on Climate Change (IPCC) (Prentice et al., 2001) estimate of gross 

annual CO2 emissions from fossil fuel combustion, cement manufacturing, and land-use change with the USEPA 

(2006) estimate of all anthropogenic non-CO2 emissions. Fossil fuel CO2 emissions associated with agriculture (e.g., 

on-farm equipment, fertilizer production) are not assigned to the agricultural sector in this estimate. 

2 The estimated increase of manure CH4 and N2O emissions represents a joint estimate based on CO2 equivalent 

units using global warming potentials (GWPs) from the IPCC Second Assessment Report. 
SECTION V — AGRICULTURE • INTRODUCTION AND BACKGROUND 

V-2 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

V.1.1 Brief Points of Comparison with Other Non-CO2 Emissions 

Sectors 

A few points about how baseline assumptions and methods for agriculture compare with those in 

other non-CO2 sectors of this report are in order. First, baseline emissions projections used in this section 

are not entirely consistent with baseline projections developed by the USEPA (2006). This is the case for 

cropland N2O and rice CH4 emissions, where separate baseline emissions projections are developed with 

process-based models. These models, described later in this section, are also used for the mitigation 

scenarios, so that assumptions and all underlying activity data on both the baseline and mitigation sides 

of the equation are consistent. 

Second, although the focus of this report is on the non-CO2 greenhouse gases, soil carbon is included 

in the agricultural analysis. Including soil carbon is important for agriculture because it provides a more 

comprehensive picture of the net greenhouse gas effects of mitigation options that primarily target N2O 

and CH4. 

Third, the agricultural analysis, like other sectors in this report, presents marginal abatement curves 

(MACs) by region, for the 2000 to 2020 period, showing the technical, net greenhouse gas mitigation 

potential at various levels of U.S. dollars (USD) per tonne of CO2 equivalent ($/tCO2eq), representing the 

breakeven price of each mitigation option. The approach used to estimate the technical mitigation 

potential is similar to that used in other sectors—a bottom-up, engineering approach. However, the 

agricultural analysis illustrates the sensitivity of the mitigation estimates to potential economic market 

feedbacks as a result of adopting the mitigation options (i.e., showing the effects of simultaneous changes 

in crop yields, livestock productivity, commodity prices, cropland area, livestock herd size, and 

emissions). 

V.1.2 Previous Estimates for EMF-21 and New Improvements 

Previously, the USEPA helped produce a non-CO2 mitigation analysis for world agriculture 

(DeAngelo et al., 2006) to assist climate-economic and integrated assessment modelers who participated 

in the EMF-21 study represent the agricultural sector. The study generated MACs by major world regions 

for cropland N2O, livestock enteric CH4, manure CH4, and rice CH4 for 2010. This analysis used a static, 

engineering approach by relying on literature sources to identify the non-CO2 reductions associated with 

each mitigation option, extrapolating those results beyond their original scale of analysis (farm, region, or 

nation) to other world regions, estimating regionally specific changes in input costs with FAOSTAT and 

other data sources, and adjusting the extent to which each mitigation option applied to different regions. 

Summary results of this previous analysis and how they compare with the current analysis are presented 

in Appendix P. 

The current analysis uses new approaches to improve on the previous EMF-21 study in a number of 

areas. First, biophysical, process-based models (DAYCENT and DNDC) are used to better capture the net 

greenhouse gas and yield effects of the cropland and rice emissions baseline and mitigation scenarios. 

The previous analysis estimated the single, dominant gas effects only (e.g., no N2O or soil carbon effects 

for rice CH4 mitigation practices). Furthermore, process-based models better reflect the heterogeneous 

emissions and yield effects over space and time of adopting mitigation practices, whereas the previous 

analysis usually assumed a uniform percentage change in emissions and/or yields across regions. The 

process-based models also ensure greater consistency in underlying assumptions and activity data 

between baseline and mitigation scenarios. For example, when emissions projections are estimated with 

IPCC Tier I default methodologies, it is not always possible to identify what underlying management 
SECTION V — AGRICULTURE • INTRODUCTION AND BACKGROUND 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES V-3

practices are taking place, which in turn makes it difficult to ascertain if the chosen mitigation options are 

indeed additional to baseline management practices. 

New mitigation options are assessed (e.g., slow-release fertilizers, nitrogen inhibitors, and no till), 

and more detailed, less aggregated results are provided for individual crop types (e.g., maize, wheat, and 

soybeans) under both irrigated and rain-fed conditions. Lastly, sensitivity experiments using a global 

agricultural trade model (IMPACT of the International Food Policy Research Institute [IFPRI]) are 

conducted to assess the agricultural commodity market effects of adopting the mitigation options. 
SECTION V — AGRICULTURE • INTRODUCTION AND BACKGROUND 

V-4 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 
SECTION V — AGRICULTURE • EMISSIONS CHARACTERIZATION, BASELINES, AND MITIGATION SCENARIOS 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES V-5

V.2 Emissions Characterization, Baselines, and Mitigation 

Scenarios 

V.2.1 Croplands (N2O and Soil Carbon) 

V.2.1.1 Cropland N2O and Soil Carbon Emissions Characterization 

N2O is typically the dominant greenhouse gas source from agricultural systems and is produced 

naturally in soils through the processes of nitrification and denitrification. These are soil microbial 

processes whereby ammonium (NH3) is reduced to nitrate (NO3) under aerobic or oxygen-rich conditions 

(nitrification), and nitrate is reduced to molecular nitrogen (N2) under anaerobic or oxygen-poor 

conditions (denitrification). A number of activities add nitrogen to soils, thereby increasing the amount 

available for nitrification and denitrification, and ultimately the amount of N2O emitted to the 

atmosphere. Activities may add nitrogen to soils either directly or indirectly. Direct additions occur 

through nitrogen fertilizer use, application of managed livestock manure and sewage sludge, production 

of nitrogen-fixing crops and forages, retention of crop residues, and cultivation of histosols (i.e., soils with 

high organic-matter content, also known as organic soils). Indirect emissions occur through volatilization 

and subsequent atmospheric deposition of applied nitrogen, as well as through surface runoff and 

leaching of applied nitrogen into groundwater and surface water. 

Other soil management activities, such as irrigation, drainage, tillage practices, and fallowing of land, 

can also affect fluxes of N2O, as well as soil carbon and fossil fuel CO2 emissions. Fossil fuel CO2

emissions can be generated on-farm by agricultural equipment and off-farm or upstream through the 

energy-intensive production of fertilizers.3 These fossil fuel CO2 emissions are not included in this study; 

thus some net emissions reduction benefits of the mitigation options are likely to be underestimated in 

this report.4

 

Agricultural soil carbon emissions and/or sequestration tend to be less dominant than N2O emissions 

in terms of the net greenhouse gas picture under baseline conditions; however, enhancing soil carbon 

sequestration represents a significant greenhouse gas mitigation option, potentially more viable than N2O 

reductions (see USEPA [2005a]). Croplands often emit CO2 as a result of conventional tillage practices 

and other soil disturbances. This occurs when soils containing organic matter that would otherwise be 

protected by vegetative cover are exposed to the air through tillage disturbances and become susceptible 

to decomposition. Conservation tillage—defined in the United States as any tillage system that maintains 

at least 30 percent of ground covered by crop residue after planting (Conservation Technology 

Information Center [CTIC], 1994)—eliminates one or several practices associated with conventional 

tillage, such as turning soils over with a moldboard plow and mixing soils with a disc plow (Lal et al., 

 

3 Under IPCC greenhouse gas inventory reporting guidelines and in the annual Inventory of U.S. Greenhouse Gas 

Emissions and Sinks reported by the USEPA, these fossil fuel CO2 emissions are reported as energy-sector not 

agricultural-sector emissions. 

4 In the USEPA (2005a), the FASOM-GHG model of U.S. forestry and agriculture shows that on-farm and upstream 

fossil fuel CO2 emissions associated with crop production are roughly 40 percent of the size of the joint CH4 and N2O 

emissions in agriculture, on a CO2-equivalent basis. The DAYCENT modelers for this report assumed that for every 

unit of nitrogen fertilizer applied, 0.8 units of CO2 were generated from fertilizer manufacturing, though these 

numbers were intentionally excluded from this report to maintain consistency across emissions categories. 
SECTION V — AGRICULTURE • EMISSIONS CHARACTERIZATION, BASELINES, AND MITIGATION SCENARIOS 

V-6 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

1998). Conservation tillage, including no-till, allows crop residues to remain on the soil surface as 

protection against erosion. 

Lastly, seasonal temperature and precipitation changes, as well as regional climate variability, 

influence rates of both soil N2O and carbon emissions. 

V.2.1.2 DAYCENT Baseline Estimates of Cropland N2O, Soil Carbon, and Yields 

The DAYCENT model is used to estimate baseline and mitigation scenario emissions of N2O and soil 

carbon for a significant share of the world’s nonrice croplands. (DAYCENT, rather than IPCC default 

values, is also the tool now used to estimate the majority of agricultural soil N2O emissions for the annual 

Inventory of U.S. Greenhouse Gas Emissions and Sinks, reported by the USEPA). Use of DAYCENT offers the 

advantage of a consistent methodology and tool across regions and between the baseline and mitigation 

scenarios. The DAYCENT model and emissions baseline methodologies are described briefly here, and 

further details are provided in Appendix Q. 

The DAYCENT model (Del Grosso et al., 2001; Parton et al., 1998) is a process-based model that 

simulates crop growth, soil organic-matter decomposition, greenhouse gas fluxes, nitrogen deposited by 

grazing animals, and other biogeochemical processes using daily climate data, land management 

information, and soil physical properties. N2O emissions estimated by DAYCENT account for nitrogen 

additions, crop type, irrigation, and other factors and capture both direct (through fertilizer applications) 

and indirect (through volatilization and leaching) N2O emissions. 

Global baseline N2O emissions for this report are estimated from DAYCENT to be 799 MtCO2eq in 

2000, 795 MtCO2eq in 2010, and 859 MtCO2eq in 2020. With the net effects of soil carbon, global net 

greenhouse gas estimates are 839 MtCO2eq, 830 MtCO2eq, and 893 MtCO2eq for 2000, 2010, and 2020, 

respectively. These estimates represent the mean of decadal averages (e.g., 1996 to 2005 mean for reported 

year 2000). Emissions estimates for individual key countries and regions are provided in Table 1-1 (see 

Section V.1.3.2 for additional baseline data). 

Table 1-1: DAYCENT N2O and Soil Carbon Estimates for 2000, 2010, and 2020 by Key Region (MtCO2eq/yr) 

2000 2010 2020 

Region N2O Soil Carbon N2O Soil Carbon N2O Soil Carbon 

United States 164 3 176 2 197 3 

EU-15 95 –4 98 –5 107 –6 

Eastern Europe 37 2 37 2 39 2 

FSU 187 26 127 30 126 36 

Mexico 14 1 16 1 17 >0 

Brazil 28 0 30 0 30 0 

India 69 –3 74 –4 78 –5 

China 84 7 95 3 105 –1 

EU-15 = European Union; FSU = Former Soviet Union. 

Note: Negative numbers indicate net sequestration. 

As described below, the cropland coverage for the DAYCENT simulations is incomplete. Therefore, 

the baseline estimates from DAYCENT are intended to serve as the foundation from which to assess the 

general implications of mitigation scenarios. The DAYCENT baseline estimates are not intended to serve 

as independent national and global inventory estimates, which can be found elsewhere in the literature 

(USEPA 2006; USEPA 2005b; Robertson 2004; IPCC 2001; Ehhalt et al., 2001; Mosier et al., 1998). 
SECTION V — AGRICULTURE • EMISSIONS CHARACTERIZATION, BASELINES, AND MITIGATION SCENARIOS 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES V-7

Appendix S describes how the DAYCENT N2O emissions baseline estimates compare with the USEPA’s 

(2006) more comprehensive estimates. 

DAYCENT explicitly simulates the major crop types only: maize, spring and winter wheat, and 

soybeans. However, analogous crops are added to these major crop types (e.g., rye, barely, and oats with 

wheat; millet and sorghum with maize) to increase the coverage of cropland area and to capture a higher 

portion of nitrogenous fertilizer applications. Grazing-land emissions are not included, and emissions 

due to residue burning are not included. For these reasons, the DAYCENT baseline N2O estimates are 

generally lower than other published inventory studies for national and world total N2O emissions. 

DAYCENT simulations for maize, wheat, and soybean areas are run under both irrigated and rainfed conditions.5 The relative portion of maize, wheat, and soybean areas under irrigated and rain-fed 

conditions are provided by IFPRI and vary by region and over time. 

Underlying data for the emissions estimates include 

global data sets of weather, soils, cropland area, and native 

vegetation, mapped to an approximate 2° × 2° resolution. 

Daily weather data (i.e., precipitation and maximum and 

minimum temperatures) from the National Oceanic and 

Atmospheric Administration (NOAA) National Centers for 

Environmental Prediction for the 1991 to 2000 period are used 

under both baseline and mitigation options; therefore, there is 

no explicit assumption about anthropogenic climate change 

for the 2000 to 2020 period. Soils data include texture 

percentages of clay, sand, and silt and come from 

FAO/UNESCO (1996). Histosols, a source of N2O, are not 

included in the simulations. Cropland distribution and the 

fractional area of specific crops are taken from both the 

International Geosphere Biosphere Programme (IGBP) land 

cover classification (Belward et al., 1999; Belward, 1996) and 

the Global Land Cover (GLC) data set of Leff et al. (2004). 

Cropland area is assumed to remain constant over time in 

the DAYCENT simulations under both baseline and 

mitigation options (the same assumption is held for rice areas 

with the DNDC simulations). The subject of changing area in 

response to market feedbacks due to the implementation of 

mitigation options is discussed in Section V.1.3.6. 

In addition to simulating N2O emissions from mineral cropland soils, a DAYCENT simulation was 

performed for those same areas as though they were covered by native vegetation and never cultivated 

(using potential vegetation from Cramer et al. [1999] and Melillo et al. [1993]), so that anthropogenic 

emissions are isolated from natural background emissions. Therefore, all reported emissions estimates 

 

5 Rain-fed conditions mean that the crop receives no extra water in addition to rainfall and the resultant water stored 

in the soil. To simulate irrigation, extra water is added, if necessary, to bring soil water content to field capacity once 

per week for 20 weeks during the growing season. This minimizes or eliminates plant water stress and is an 

assumption consistent with the fact that farmers typically irrigate only when necessary because irrigation requires 

resources. 

Box 1-1: DAYCENT Estimates of U.S. 

Agricultural N2O Emissions in This 

Report versus Inventory 

The annual Inventory of Greenhouse Gas 

Emissions and Sinks, reported by the 

USEPA, now uses the DAYCENT 

model to estimate the majority of 

agricultural soil N2O emissions. 

Though DAYCENT is used in this 

report and provides estimates for U.S. 

agricultural soil N2O emissions under 

baseline and mitigation scenarios, the 

U.S. estimates in this report are not the 

same as the U.S. estimates in the 

Inventory. This is because the 

Inventory uses input data specific to 

the United States, while the input data 

used by DAYCENT in this report come 

from global data sets to provide as 

much consistency as possible across 

regions, including the United States. 
SECTION V — AGRICULTURE • EMISSIONS CHARACTERIZATION, BASELINES, AND MITIGATION SCENARIOS 

V-8 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

under both baseline and mitigation scenarios from croplands represent anthropogenic emissions 

separated from natural background emissions.6

Synthetic nitrogenous fertilization rates are based on globally uniform relationships with current and 

projected production of the major crop types by region. Current and historic nitrogenous fertilization 

data for each region are from FAOSTAT (2004b) and the International Fertilizer Industry Association 

(IFA) (2002). Current nitrogenous fertilization rates (kg/hectare) were assumed to be the same as 1998 

levels, and projected rates were scaled from this base. Projected fertilization rates for wheat and maize 

were taken from regression equations based on crop production from FAO (2000); for soybeans, an 

analogous regression equation was developed using a combination of FAOSTAT (2004b) and IFA (2002) 

(see Appendix Q). Regionally specific projections of crop yields from IFPRI for 2010 and 2020 are used 

with these equations to derive future fertilization rates. Crop area is assumed to remain constant for the 

DAYCENT simulations. Increases in N2O out to 2020 for most regions (see Table 1-1) are therefore the 

result of increasing rates of fertilization based on yield projections. All baseline fertilizer applications for 

all regions are assumed to be administered in one application. 

Organic-matter fertilizer additions are assumed to be a function of animal numbers by region. 

Historical trends in organic fertilizer use were calculated from animal numbers reported by FAOSTAT 

(2004a), using IPCC default factors concerning region-specific average nitrogen excretion per animal, and 

the percentage of nitrogen distributed among waste management practices (see Appendix Q for IPCC 

default factors). Projections of manure nitrogen are taken from underlying activity data used for USEPA 

(2006). 

Nonspatial data (such as planting date and fertilizer application rates) were assigned as point values 

for each region or country and were assumed to be the same within each region. Global maps of 2° × 2° 

resolution for baseline N2O emissions estimated by DAYCENT for areas of wheat, maize, and soybeans 

are presented in Appendix Q (under rain-fed conditions only). 

V.2.1.3 Mitigation Options for Cropland N2O and Soil Carbon Emissions 

Mitigation options for croplands have been identified that could decrease N2O emissions, often the 

result of applying fertilizer that exceeds crop demand, while maintaining yields (e.g., Mosier et al., 2002). 

Mitigation options are chosen with this goal in mind. Options are listed in Table 1-2. The soil N2O 

mitigation options involve either more efficient (or simply reduced) application of nitrogen-based 

fertilizers (e.g., adding nitrification inhibitors; using split fertilization; reducing baseline nitrogen 

fertilization by 10, 20, or 30 percent) or adoption of no-till cultivation methods. Because the focus of this 

report is on the non-CO2 greenhouse gas emissions, additional options that might increase soil carbon 

(e.g., reduced fallow periods, different cropping mix) are not considered. 

These mitigation options are simulated by DAYCENT and resulting crop yields (of wheat, maize, and 

soybeans), and emissions effects are compared with the DAYCENT baseline, as described above. Though 

all mitigation options are represented in the final MACs, DAYCENT simulates only one mitigation option 

at a time, assuming that each mitigation option is implemented on all croplands in 2000 and continuously 

until 2020. No mitigation options are implemented simultaneously on the same croplands, or on different 

portions of the croplands, within DAYCENT. 

 

6 This approach of isolating anthropogenic emissions from natural background emissions is also used when the 

DAYCENT model is applied to estimate anthropogenic N2O emissions from agricultural soils for the Inventory of U.S. 

Greenhouse Gas Emissions and Sinks, reported by the USEPA. 
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GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES V-9

Table 1-2: Cropland N2O and Soil Carbon Mitigation Options Run Through DAYCENT 

Mitigation 

Option Description 

Greenhouse Gas 

Effects 

Split fertilization Application of same amount of nitrogen fertilizer as in baseline but divided 

into three smaller increments during crop uptake period to better match 

nitrogen application with crop demand and reduce nitrogen availability for 

leaching, nitrification, denitrification, and volatilization. 

N2O, some soil carbon 

Simple fertilization 

reduction—10 

percent 

Reduction of nitrogen-based fertilizer from one-time baseline application of 

10 percent. 

N2O, some soil carbon 

Simple fertilization 

reduction—20 

percent 

Reduction of nitrogen-based fertilizer from one-time baseline application of 

20 percent. 

N2O, some soil carbon 

Simple fertilization 

reduction—30 

percent 

Reduction of nitrogen-based fertilizer from one-time baseline application of 

30 percent. 

N2O, some soil carbon 

Nitrification inhibitor Reduces conversion of ammonium to NO3, which slows the immediate 

availability of nitrate (nitrate is water soluble). The inhibition of nitrification 

reduces nitrogen loss and increases overall plant uptake. 

N2O, some soil carbon 

No-till Conversion from conventional tillage to no till, where soils are disturbed 

less and more crop residue is retained. 

Soil carbon, some N2O 

As in the baseline scenario, each DAYCENT mitigation simulation is run according to the relative 

portions of maize, wheat, and soybean areas under either irrigated or rain-fed management. 

A number of mitigation options are found to increase net greenhouse gas emissions relative to the 

baseline depending on crop, management, region, and time period. These options are removed to 

estimate and construct the abatement curves. The number of options that increase net emissions grows 

from the 2000 to the 2010 to the 2020 period. All of these options occur on either wheat or maize 

croplands, are spread over most regions of the world, and predominantly involve reducing baseline 

nitrogen fertilizers. The primary reason why decreasing nitrogen fertilizer use leads to an increase in net 

GHG in some regions is a decrease in soil carbon—due to lower plant growth from the fertilizer 

reductions and hence less residue returning to the soil—which more than compensates for the lower N2O 

emissions. A small number of Asian regions experience an increase in emissions for the split-fertilization 

option, which can occur if more frequent (but smaller) fertilizer applications coincide with rainy periods; 

however, the timing of the applications for this option was assumed to be uniform across regions. In 

practice, farmers would time fertilizer applications based on their local weather conditions and on plant 

growth stages. In addition, some of the no-till scenarios in Western Europe increase net emissions; this is 

primarily because no till allows for greater soil water content and enhances denitrification to produce 

N2O emissions. 
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V-10 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

V.2.1.4 DAYCENT Results for Changes in Cropland N2O, Soil Carbon, and Yields 

Figure 1-1 summarizes total global production of the major crops of wheat, maize, and soybeans 

under baseline and mitigation scenarios, holding area constant. DAYCENT simulations were performed 

for both irrigated and nonirrigated conditions. In every case, production is higher with irrigation, as 

expected. All three of the options that were effective in reducing emissions (i.e., nitrification inhibitors, 

split-fertilization, and conversion to no till) simultaneously increased production. The three options that 

involved reduced fertilization, on the other hand, resulted in substantial reductions in production. 

Figure 1-1: Global Cropland Yields for Baseline and Mitigation Options Estimated by DAYCENT, 2010a 

Note: This figure shows total global production of wheat, maize, and soybeans—the three major crops modeled using 

DAYCENT—simulated under the baseline and mitigation options. a Ninhib—addition of nitrification inhibitor (irrigated and nonirrigated). 

Split—split fertilization, dividing fertilizer applications into three smaller increments. 

Red70—reduction of nitrogen-based fertilizer to 70 percent of baseline. 

Red80—reduction of nitrogen-based fertilizer to 80 percent of baseline. 

Red90—reduction of nitrogen-based fertilizer to 90 percent of baseline. 

Reduced nitrogen fertilizer leads to reduced yields because plant growth rates, and hence crop yields, 

are highly sensitive to nutrient supply in DAYCENT. That is, DAYCENT assumes that plant growth is 

limited by nutrient availability, as well as by water and temperature. Nitrification inhibitors and split 

fertilizer caused the largest increase in yields because both of these options maintain higher nitrogen 

availability for plants. Nitrification inhibitors keep more nitrogen in the root zone for two reasons: less 

nitrogen is lost from the soil as nitrogen gas and, because the conversion of ammonium (NH4) to NO3 is 

inhibited, less NO3 is leached below the root zone. Split-nitrogen application increases plant-available 

nitrogen, because nitrogen supply is more synchronized with plant-nitrogen demand. Higher plantnitrogen uptake also reduces nitrogen losses from nitrification, denitrification, and leaching, although to a 

lesser extent than the nitrification inhibitor, for the reasons discussed above. 

As shown in Figure 1-2, DAYCENT simulations for corn, soy, and wheat suggest that using 

nitrification inhibitors and no-till cultivation lead to the largest reduction in net greenhouse gas emissions 

at the global scale. Surprisingly, reduced nitrogen fertilizer leads to net emissions similar to the baseline 

scenario. The decrease in crop production associated with reduced fertilizer applications leads to reduced 

1,500

1,700

1,900

2,100

2,300

2,500

Base

Base Irri

N Inhib

N Inhib Irri

Split

Split Irri

Red70

Red70 Irri

Red80

Red80 Irri

Red90

Red90 Irri

NT

NT irri

Baseline and Mitigation Options

Tg dry biomass
SECTION V — AGRICULTURE • EMISSIONS CHARACTERIZATION, BASELINES, AND MITIGATION SCENARIOS 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES V-11

Figure 1-2: Global Net Greenhouse Gas (N2O and Soil Carbon) Cropland Emissions Estimated by 

DAYCENT under Baseline and Mitigation Scenariosa

a Ninhib—addition of nitrification inhibitor. 

Split—split fertilization, dividing fertilizer applications into three smaller increments. 

Red70—reduction of nitrogen-based fertilizer to 70 percent of baseline. 

Red80—reduction of nitrogen-based fertilizer to 80 percent of baseline. 

Red90—reduction of nitrogen-based fertilizer to 90 percent of baseline. 

NT—conversion from conventional tillage to no-till. 

soil inputs and, hence, reduced soil carbon. Observations show that soil carbon levels are sensitive to 

changes in crop residue inputs (e.g., Peterson et al. [1998]); however, the degree to which a particular soil 

responds to changes in crop residue inputs depends on many factors, such as the history of land-use 

management. The soil carbon reduction offsets the reduced N2O emissions to varying degrees. The net 

emissions for the three different fertilizer reduction amounts (10, 20, and 30 percent) are similar. This 

suggests that, at the global scale, the amount of soil carbon lost and the amount of N2O reduced respond 

roughly linearly and equally to fertilizer inputs. 

An additional consideration regarding potential trade-offs between N2O emissions and soil carbon is 

that N2O reductions are long lasting, whereas soil carbon accumulation is reversible through future 

changes in management. The reversibility of soil carbon accumulation is not accounted for in this 

analysis, because all changes in management are assumed to occur immediately and continuously 

through to 2020. 

The nitrification inhibitor leads to the largest reduction in net emissions because it directly decreases 

emissions from nitrification. Split fertilization also leads to significant net reductions, but it is possible 

that the DAYCENT simulation is underestimating the mitigation potential of this option. This is because 

the three separate fertilizer applications are occurring on the same day, regardless of the timing and 

amount of rainfall represented in the model. If heavy rains happen to fall a couple of weeks after the 

second fertilizer application, N2O may be higher than if all of the fertilizer were applied when the crop 

was planted. 

No-till cultivation leads to a large reduction in net emissions primarily because of increased carbon 

storage in soil and surface residue, although this option also decreases N2O by a small amount at the 

0

100

200

300

400

500

600

700

800

900

1,000

Baseline Ninhib Split Red70 Red80 Red90 NT

Baseline and Mitigation Options

TgCO2eq

2000 2010 2020
SECTION V — AGRICULTURE • EMISSIONS CHARACTERIZATION, BASELINES, AND MITIGATION SCENARIOS 

V-12 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

global scale. However, DAYCENT does project higher N2O emissions under no till for certain locations, 

which is consistent with data showing higher N2O emissions under no till, particularly in humid 

environments (Smith and Conen, 2004). Because the majority of the reduced greenhouse gas emissions 

from the no-till option are from carbon storage, it should be noted that this benefit is transitory, because 

the capacity of soils to store carbon is finite and most soils are likely to reach equilibrium within 

approximately 50 years of land management change. Also, if cultivation intensity is increased in the 

future, then much of the carbon that was stored is likely to be respired and returned to the atmosphere. 

However, the reduced N2O emissions associated with applying nitrification inhibitors and split fertilizer 

are irreversible and likely to persist indefinitely. 

To estimate the breakeven $/tCO2eq of these mitigation options, DAYCENT results for the change 

(from baseline) in net emissions, yields, and fertilizer applications are used in combination with crop and 

fertilizer price information, as well as assumptions about other input costs and labor changes. The change 

in crop revenue is estimated with DAYCENT changes in yields and IFPRI’s current and projected regionspecific baseline prices for wheat, maize, and soybeans. Likewise, IFPRI price information for change in 

fertilizer costs is used. Appendix T provides details on IFPRI’s commodity prices. 

No capital costs are assumed for any cropland mitigation options.7 The nitrification inhibitor option 

is assumed to incur an additional input cost of $20 per hectare (Scharf et al., 2005), which is scaled from 

the United States to other regions. Only two of the options are assumed to incur labor changes. Split 

fertilization is assumed to require an increase in labor and no till a decrease in labor.8

 These percentage 

changes in labor are assumed to be uniform across regions; however, data from the Global Trade 

Analysis Project (GTAP, 2005) database are used to calculate the share of output attributable to labor costs 

by crop for each region. This share is used to calculate baseline labor costs per hectare from the estimated 

value of output per hectare by crop and by region. Labor rates are taken from IFPRI’s IMPACT model to 

calculate the implied number of labor hours per hectare consistent with the labor cost per hectare, as a 

validity check on the labor costs being estimated. Section V.1.3.1 provides additional information on how 

these individual parameters are used to estimate costs. 

V.2.2 Rice (CH4, N2O, and Soil Carbon) 

V.2.2.1 Rice CH4, N2O, and Carbon Emissions Characterization 

Most rice in Asia and the rest of the world is grown in flooded paddy fields (less than 10 percent of 

the rice in Asia is grown in upland conditions). When fields are flooded, decomposition of organic 

material gradually depletes the oxygen present in the soil and floodwater, causing anaerobic conditions 

 

7 No-till options would require purchasing no-till equipment for direct planting. However, if this equipment is 

purchased in place of equipment used for traditional tillage, there may be little incremental capital costs associated 

with no till. Some crop budgets actually indicate lower capital costs for no till because of the need for fewer passes 

over the field, which leads to reduced equipment depreciation. Thus, no incremental capital costs for the no-till 

option are assumed. 

8 Split fertilization is assumed to require 14 percent more labor, assuming one additional pass over the fields, where, 

for this purpose, seven passes per year are assumed in the baseline (i.e., for tilling, planting, fertilizing, applying 

herbicide, applying pesticide, and harvesting, some of which may not be done on all fields but may require more 

than one pass on some farms). The biophysical modeling in DAYCENT assumes a one-time fertilizer application in 

the baseline and two applications with split fertilization. No till is assumed to decrease labor requirements based on a 

U.S. Department of Agriculture (USDA) Agricultural Resource Management Survey (ARMS) survey, which provides 

labor estimates for conventional and conservation tillage on both irrigated and rain-fed land by major crop. 
SECTION V — AGRICULTURE • EMISSIONS CHARACTERIZATION, BASELINES, AND MITIGATION SCENARIOS 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES V-13

in the soil to develop. Anaerobic decomposition of soil organic matter by methanogenic bacteria 

generates CH4. Varying amounts up to 90 percent of the CH4 is oxidized by aerobic methanotrophic 

bacteria in the soil (Krüger et al., 2002; Holzapfel-Pschorn et al., 1985; Sass et al., 1990). Some of the CH4 is 

also leached away as dissolved CH4 in floodwater that percolates from the field. The remaining 

unoxidized CH4 is transported from the soil to the atmosphere, primarily through the rice plants 

themselves. Minor amounts of CH4 also escape from the soil via diffusion and bubbling through 

floodwaters. 

The water management system under which rice is grown is therefore one of the most important 

factors affecting CH4 emissions. The amount of available carbon susceptible to decomposition is also 

critical. Some flooded fields are drained periodically during the growing season, either intentionally or 

accidentally. If water is drained and soils are allowed to dry sufficiently, CH4 emissions decrease or stop 

entirely. This is due to soil aeration, which not only causes existing soil CH4 to oxidize but also inhibits 

further CH4 production in soils. 

Field measurements in China indicate, however, that midseason drainage, while significantly 

reducing CH4, actually increases N2O emissions (Zheng et al., 1997, 2000; Cai et al., 1999). One of the key 

processes controlling CH4 and N2O production/consumption in paddy soils is the reduction potential 

(Eh) dynamics. Methane and N2O are produced during different stages of soil redox potential 

fluctuations. 

In addition to water management, other practices (e.g., tillage, fertilization, manure amendments) 

will alter the soil environmental conditions (e.g., temperature, moisture, pH) and hence affect the soil 

carbon- and nitrogen-driving processes such as decomposition, nitrification, and denitrification. The 

changes in the soil biogeochemical processes will finally affect the availability of soil nitrogen and water 

to the crops and hence alter the crop yields. Because crop residue is the major source of soil organic 

carbon, the change in crop yield and litter will redefine the soil organic-matter balance, which is one of 

the most important factors determining the CH4, soil CO2, and N2O emissions (Li et al., 2006). 

Soil temperature is also known to be an important factor regulating the activity of methanogenic 

bacteria and, therefore, the rate of CH4 production. 

V.2.2.2 DNDC Baseline Estimates of Rice CH4, N2O, Soil Carbon, and Yields 

The DNDC model, in particular the paddy-rice version of the model (DNDC 8.6; Li et al., 2004; Li et 

al., 2002; Cai et al., 2003; Zhang et al., 2002), was used to estimate baseline and mitigation scenario 

emissions of CH4, N2O, and soil carbon, as well as yield and water resource changes, for Asian rice 

systems. Greenhouse gas emissions from non-Asian rice systems, which represent about 10 percent of the 

world’s total rice area (Wassmann et al., 2000), are excluded, primarily because data for these areas were 

not available at the time of the DNDC modeling. The DNDC model and emissions baseline 

methodologies are briefly described here, and further details are provided in Appendix R. Appendix S 

summarizes differences between the baseline rice GHG emissions used in this analysis and USEPA 

(2006). 

DNDC is a soil biogeochemical model that simulates both aerobic and anaerobic soil conditions and 

estimates crop yields based on a detailed crop physiology-phenology model. It is designed for assessing 

the impact of different management strategies on short-term and long-term soil organic carbon dynamics 

and emissions of CH4, N2O, nitric oxide (NO), and NH3 from both upland and wetland agricultural 

ecosystems. DNDC requires data on soils (e.g., pH, soil carbon, bulk density, and soil texture), rice 

cropping areas and systems (e.g., single rice, double rice, rice rotated with upland crops), climate, and 

management practices (e.g., fertilizer use, planting and harvesting dates, tillage, water use). DNDC runs 
SECTION V — AGRICULTURE • EMISSIONS CHARACTERIZATION, BASELINES, AND MITIGATION SCENARIOS 

V-14 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

on a daily time step and can therefore capture temporal, as well as spatial, heterogeneity in emissions 

processes. 

DNDC has been tested against several CH4 and N2O flux data sets for wetland rice systems in 

different regions of the world, and overall results indicate that DNDC is capable of estimating the 

seasonal patterns and magnitudes of CH4 and N2O fluxes. In some cases (less than 20 percent of the sites 

tested), there were discrepancies between modeled and observed patterns of CH4 and N2O fluxes. In 

these cases, minor modifications to capture unique local management conditions, rice varieties, and 

anaerobic processes resulted in good estimates of greenhouse gas emissions from all rice systems tested 

(Li et al., 2006; Cai et al., 2003; Zhang et al., 2002; see also Appendix R). 

DNDC simulates rice growth and yield by tracking heat (i.e., daily temperature) accumulation, water 

availability, and nitrogen availability. If there is any stress in heat, water, or nitrogen detected by DNDC, 

the yield will be reduced accordingly. The impacts of farming practices on yield are modeled based on 

the effects of the practices on water and nitrogen (it is assumed the practices have little effect on heat 

flux). 

China is the core focus of the rice component of this study because China contains roughly 20 percent 

of the world’s rice paddies and generates 31 percent of the world’s rice production (FAOSTAT, 2004a); 

furthermore, previous DNDC modeling efforts had already collected a detailed database for Chinese rice 

systems at the county scale. This Chinese rice component of the analysis is described in Li et al. (2006) and 

briefly summarized here. 

Table 1-3 contains DNDC estimates of rice emissions for China, individual water basin regions within 

China, and other Asian countries (see Section V.1.3.3 for additional baseline summary information). 

Methane emissions tend to increase over time because of soil carbon accumulation. N2O emissions tend to 

decline, also because of the soil carbon accumulation, coupled with an assumed constant rate of 

fertilization (which increases total denitrification). 

Data on rice cropping systems, soils, climate, water management, residue management, fertilizer, and 

optimum yield profiles are incorporated into DNDC for each of the approximately 2,500 Chinese 

counties. County data are aggregated to water basin regions within China. Maximum and minimum 

values of soil texture, pH, bulk density, and soil organic carbon content are derived for each county. 

These factors are used to determine the most sensitive factors to estimate uncertainty in emissions 

estimates within each county. Based on sensitivity tests (Li et al., 2004), the most sensitive factors for CH4

and N2O emissions from rice paddies are soil texture and soil organic carbon. By varying soil texture and 

soil organic carbon over the ranges reported in the county-scale database, a range of CH4 and N2O 

emissions for each cropping system in each county is estimated. All emissions estimates from DNDC in 

this study represent the midpoints of those ranges. 

There are 11 different crop rotations, including single rice, double rice, rice-winter wheat, ricerapeseed, and rice-rice-vegetable. The area occupied by each rotation in each county is quantified by 

combining the county-scale statistical database of crop-sown areas with a Landsat land-cover map for 

mainland China (Frolking et al., 2002). Total rice area is assumed to remain fixed over the 2000 to 2020 

period under both baseline and mitigation scenarios, though regional changes in rice area are certainly 

expected to occur; the subject of changing rice area in response to implementing the mitigation options is 

discussed in Section V.1.3.6. 
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GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES V-15

Table 1-3: Rice-Only Baseline CH4, N2O, and Soil Carbon Estimates for 2000, 2010, and 2020 by Asian 

Region (Midpoints from DNDC in MtCO2eq/yr; Negative Carbon Numbers Indicate Net 

Sequestration) 

2000 2010a 2020b

Region CH4 N2O 

Soil 

Carbon CH4 N2O 

Soil 

Carbon CH4 N2O 

Soil 

Carbon 

China 211 199 –25 217 132 –48 223 114 –35 

Huaihe 41 23 –4 43 18 –6 44 15 –4 

Haihe 3 2 –1 3 1 –1 4 1 –0 

Huanghe 2 1 –1 2 1 –0 2 1 –0 

Changjian 87 104 –18 90 65 –24 92 56 –18 

Songliao 23 8 6 24 6 –2 24 6 –1 

Inland 1 0 –0 1 0 –0 1 0 –0 

Southwest 1 2 1 1 1 –1 1 1 –0 

ZhuJiang 33 38 –2 34 25 –10 35 21 –8 

Southeast 19 20 –6 20 15 –5 20 13 –4 

Bangladesh 41 4 13 45 2 –1 47 2 –2 

India 103 5 19 111 10 –9 117 15 –10 

Indonesiac 131 36 257 139 5 78 150 4 65 

Philippines 58 7 36 60 2 7 64 2 6 

Thailand 66 6 70 69 3 14 73 3 12 

Vietnam 45 6 40 73 3 7 80 3 6 

a Average of 2006–2010. 

b Average of 2016–2020. 

c Indonesia has exceptionally large baseline decreases in soil carbon because it is starting from a very high initial soil carbon content (about 7 

percent). 

Total emissions are estimated from total sown area, including all rice systems that capture more than 

one rice crop (i.e., double rice) for multiple growing seasons over the course of a year. Rice yields in 

DNDC, however, are estimated from single-rice systems only and are assumed to be representative of 

other types of rice systems (i.e., double rice and rice-winter wheat).9

Daily weather data (i.e., maximum and minimum air temperatures and precipitation) for 1990 from 

610 weather stations in China were acquired from the National Center for Atmospheric Research 

(http://dss.ucar.edu/datasets/ds485.0/). Climate data for 1990 are used for baseline and mitigation 

scenarios; thus, as with the DAYCENT modeling runs, there is no explicit assumption about 

anthropogenic climate change out to 2020. Climate, biophysical, and management conditions are 

assumed to be the same within each county but vary across counties. 

Midseason drainage is assumed to be a baseline management practice for a fixed percentage (80 

percent) of Chinese paddies currently and out to 2020; the remaining 20 percent is assumed to be under 

continuous flooding. Shen et al. (1998) estimate that 80 percent of Chinese rice systems have made the 

 

9 There are plans to modify the DNDC model so that yields for multiple types of rice cropping systems, in addition to 

single-rice systems, can be tracked separately. 
SECTION V — AGRICULTURE • EMISSIONS CHARACTERIZATION, BASELINES, AND MITIGATION SCENARIOS 

V-16 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

conversion from continuous flooding to midseason drainage, a practice that decreases CH4 emissions 

because it decreases the period over which anaerobic conditions occur. Under midseason drainage, three 

drainage events are assumed to be carried out for each rice-growing season. 

Optimal Chinese rice yields in DNDC were set to increase by 1 percent per year over the 2000 to 2020 

period to match yield projections from IFPRI’s IMPACT model. As a result, realized yields in DNDC do 

increase over time but fall short of the prescribed optimal yields due to nutrient limitations, primarily 

insufficient nitrogen availability. 

Fertilizer applications are assumed to be 140 kgN/hectare (70 kgN of urea and 70 kgN of ammonium 

bicarbonate) for each rice-growing season. These rates remain fixed over the 2000 to 2020 period. Rice 

straw (1,000 kg-C) is also amended at the beginning of each rice-growing season. No manure is applied. 

Less detailed DNDC analyses are carried out for other Asian regions. These emissions analyses are 

not intended to serve as national inventory studies but rather to provide a basis from which to assess the 

effects of the different mitigation options. DNDC is run for individual sites under both rain-fed and 

irrigated conditions in Bangladesh, India, Indonesia, Japan, the Philippines, Thailand, and Vietnam. For 

each site, soil and climate data were compiled from several sources (Global Soil Data Task Group, 2000; 

Kistler et al., 2001; Webb et al., 2000). To estimate national-level emissions, the simplified assumption is 

made that the site-level conditions are representative of the entire country. Therefore, net emissions (CH4, 

N2O, soil carbon) rates per hectare from these test sites are multiplied by the number of hectares under 

either irrigated or rain-fed conditions in each country, according to data from the International Rice 

Research Institute (IRRI). These areas also remain fixed over the 2000 to 2020 period. Like the DNDC 

simulations in China, optimal yield projections out to 2020 from IFPRI (see Appendix R) are used to allow 

annual baseline yields in DNDC to increase at different rates in different countries. 

Midseason drainage is currently not widely practiced outside of China; for this reason, the dominant 

baseline management condition assumed in these other Asian regions is continuous flooding under either 

irrigated or rain-fed conditions. Fertilization types and rates are assumed to be the same as in China. 

DNDC simulations were not carried out for Malaysia, Myanmar, South Korea, and other Southeast Asian 

countries, but nationally averaged emissions and yield results from DNDC in neighboring regions are 

used as proxies (see Appendix R). 

V.2.2.3 Mitigation Options for Rice CH4, N2O, and Soil Carbon Emissions 

The mitigation options chosen for rice emissions have been identified as viable options in the 

literature (e.g., Wassmann et al. [2000]; Van der Gon et al. [2001]). Table 1-4 lists these mitigation options, 

which include changes in water management that reduce the time over which flooding conditions occur 

(to reduce anaerobic conditions), use of alternative fertilizers and changes in the timing of organic 

amendments (to inhibit methanogenesis), or switching from flooded to upland rice to eliminate anaerobic 

conditions. 

Unlike China, most other Asian countries have larger fractions of rice areas under rain-fed 

management conditions. Mitigation options requiring a change in water management are not simulated 

on rain-fed areas because these systems are water limited and rely only on precipitation. Mitigation 

options involving fertilizer management and conversion to upland rice are assessed on all rice areas. 

All mitigation options are intended primarily to reduce baseline CH4 emissions, but N2O emissions 

and soil carbon are affected as well. Emissions reductions represented in the final cost estimates represent 

these net greenhouse gas effects. The mitigation options are simulated by DNDC, and resulting rice crop 

yields and emissions effects are compared with the DNDC baseline, as described above. Although all 
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GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES V-17

Table 1-4: Rice CH4, N2O, and Soil Carbon Mitigation Options Run Through DNDC 

Mitigation Option Description Greenhouse Gas Effects 

Full midseason 

drainage 

In China, shift from 80 percent to 100 percent adoption of 

midseason drainage. In rest of Asia, conversion from 0 percent to 

100 percent. Rice fields are dried three times within a growing 

season and surface water layer is 5 to 10 cm for remaining, flooded 

period. Not applied on rain-fed areas. 

CH4, N2O, soil carbon 

Shallow flooding Assumes rice paddies are marginally covered by flood water, with 

the water table fluctuating 5 to 10 cm above and below soil surface. 

Not applied on rain-fed areas. 

Same 

Off-season straw Shifting straw amendment from in-season to off-season can reduce 

availability of dissolved organic carbon and; thus, methanogens. 

Assumes rice straw is applied 2 months before rather than at 

beginning of rice-growing season. 

Same 

Ammonium sulfate Baseline fertilizers, urea, and ammonium bicarbonate, replaced 

with 140 kg/hectare of ammonium sulfate. Sulfate additions to soil 

can elevate reduction potential, which suppresses CH4 production. 

Same 

Slow-release 

fertilizer 

Nitrogen is slowly released from coated or tablet fertilizer over a 

30-day period following application. Applied in the same amount 

and at the same time as in baseline case. Increases fertilizer-use 

efficiency. 

Same 

Upland rice Assumes upland rice replaces existing paddy rice areas and that 

fields do not receive any flood water. 

Same 

mitigation options are represented in the final MACs, DNDC simulates only one mitigation option at a 

time, assuming that each mitigation option is implemented on all rice lands in 2000 and continuously 

until 2020. No mitigation options are implemented simultaneously on the same rice lands or on different 

portions of the rice lands within DNDC. 

Unlike the options with DAYCENT, no options that were found to increase net emissions relative to 

baseline are removed from the rice portion of the analysis, because these net emissions increases were 

generally small or temporary (i.e., occurring only in the later years of the analysis). 

V.2.2.4 DNDC Estimates for Changes in Rice CH4, N2O, Soil Carbon, and Yields 

Results here provide the most detail for China because that is the country for which the most detailed 

DNDC modeling runs were carried out. Table 1-5 provides net greenhouse gas results aggregated to the 

Chinese national level for the baseline and mitigation scenarios, averaged over the entire 2000 to 2020 

period. The midpoint estimates from DNDC are those carried forward in the MAC calculations. 

Table 1-5: DNDC Estimates of Net Greenhouse Gas Results for Baseline and Mitigation Scenarios for China 

(Annual Averages in MtCO2eq/yr over 2000–2020) 

Estimate Baseline 

Midseason 

Drainage 

Shallow 

Flooding 

Off-Season 

Straw 

Ammonium 

Sulfate 

Slow-Release 

Fertilizer 

Upland 

Rice 

Midpointa 315 296 140 298 235 326 41 

High estimate 484 445 232 468 379 454 71 

Low estimate 146 148 47 128 90 199 11 

Source: Li et al., 2006. 

a The high, mid, and low estimates are the results of most sensitive factor (MSF) estimates carried out with the DNDC model. 
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V-18 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

Table 1-6 shows individual greenhouse gas changes from the baseline, as well as the net greenhouse 

gas and yield changes, at the Chinese national level on a per-hectare basis; change in water-use 

requirements are also shown but are not used in the final cost estimates because water is not a priced 

commodity in these rice systems. 

Table 1-6: Changes from Baseline in Greenhouse Gas Emissions, Crop Yields, and Water Consumption for 

China (Annual Averages over 2000–2020; Negative Numbers Indicate Decreases Relative to the 

Baseline) 

CH4 N2O CO2 Net Greenhouse Gas Yield Water 

Management Option (kgCO2eq/ha) (kgCO2eq/ha) (kgCO2/ha) (kgCO2eq/ha) (kg C/ha) (mm/yr) 

Midseason drainage –2,411 1,283 –1 –1,129 81 –9 

Shallow flooding –7,402 –2,440 591 –9,251 134 –248 

Off-season straw –663 –40 21 –682 43 0 

Ammonium sulfate –367 –3,668 –85 –4,120 28 0 

Slow-release fertilizer 287 727 –191 823 131 0 

Upland rice –11,794 –3,018 239 –14,573 –381 –566 

Source: Li et al., 2006. 

As described in Li et al. (2006), despite large-scale adoption of midseason drainage, there is still large 

technical potential for additional CH4 reductions from Chinese rice paddies (e.g., over 60 percent 

reductions are achieved in the shallow flooding scenario over 2000 to 2020). However, management 

changes that reduce CH4 emissions simultaneously affect N2O emissions and soil carbon dynamics such 

that the net greenhouse gas effects should be considered. Midseason drainage, for example, is an effective 

CH4 reduction strategy but can significantly increase N2O emissions. Ammonium sulfate reduces CH4 by 

a small amount but significantly reduces N2O; these low CH4 reductions are largely due to the fact that 

mid-season drainage rather than continuous flooding is the baseline practice (conditions under which 

sulfate is less effective at reducing CH4), whereas more significant N2O reductions occur because 

ammonium sulfate is less susceptible to volatilization than the urea it is replacing (because all of the 

nitrogen is already in the ammonium form). 

In terms of net greenhouse gas technical mitigation potential only, the most effective mitigation 

option appears to be shallow flooding, followed by ammonium sulfate, full midseason drainage 

adoption, and off-season straw amendments; the slow-release fertilizer scenario enhances soil carbon but 

increases the other gases and thus does not reduce net greenhouse gas emissions compared with the 

baseline. The upland rice scenario, where it is assumed that existing rice fields receive no flood water, is 

simulated in DNDC for China and is found to decrease net greenhouse gas emissions by about 87 

percent. 

The relative order of mitigation across scenarios remains the same even when the proportions of 

midseason drainage vary (Li and Salas, 2005), suggesting that these results may apply to other regions 

where midseason drainage has not been widely adopted. Appendix R contains information about the 

time dynamics of these net greenhouse gas changes for each scenario for 2000 to 2020. 

Most mitigation options, including slow-release fertilizer, increase rice yields compared with the 

baseline. In general, rice yields vary directly with nitrogen availability, assuming no heat stress and 

sufficient water resources: higher nitrogen availability leads to higher yields. Relative to continuous 

flooding, midseason drainage or shallow flooding elevates soil aeration and hence accelerates 

decomposition, which produces more inorganic nitrogen and increases nitrogen availability. Slow-release 
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GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES V-19

fertilizer improves the fertilizer use efficiency by extending the period of nitrogen availability for the 

plants, effectively increasing total nitrogen availability. Similar to the slow-release fertilizer, ammonium 

sulfate has relatively low solubility compared with baseline fertilizer, urea, and ammonium bicarbonate 

and thus is less susceptible to leaching. Although theoretically off-season straw may not have a direct 

effect on yield, it is assumed that early incorporation of straw favored its decomposition because of the 

high reduction potential conditions before flooding. This higher decomposition rate enhanced yields 

caused by increased soil nitrogen availability when the rice was transplanted. The yield difference 

between upland rice and paddy rice is in the rice’s genetic characteristics. The current upland rice has 

genetically low yield. This situation may change if new strains of upland rice are developed. In summary, 

management practices that increase nitrogen availability (through increased decomposition or better 

synchronization with plant needs) will typically increase rice yields. 

Shifting to full midseason drainage and shallow flooding are also water-saving practices because they 

significantly decrease water consumption (i.e., evapotranspiration), whereas the other mitigation options, 

involving only changes in fertilization or straw amendment, have almost no effect on water consumption. 

Table 1-7 shows net greenhouse gas results under each mitigation option compared with the baseline 

for the other Asian countries. The pattern of results observed in China is similar for these other countries. 

The most effective mitigation options in terms of net greenhouse gas reductions involve a change in 

water management; the options involving a change in fertilization management are less effective. Slowrelease fertilizer is also a particularly poor greenhouse gas reduction strategy in these other Asian 

countries, often leading to no net greenhouse gas reductions compared with the baseline. 

Table 1-7: Net Greenhouse Gas Results for Baseline and Mitigation Options for Other Asian Countries 

(Annual Averages in MtCO2eq/yr over 2000–2020) 

Country Baseline 

Midseason 

Drainage 

Shallow 

Flooding 

Off-Season 

Straw 

Ammonium 

Sulfate 

SlowRelease 

Fertilizer 

Upland 

Rice 

Bangladesh 47 23 8 32 43 47 21 

India 113 60 23 79 101 115 41 

Indonesia 237 139 142 193 223 238 190 

Japan 29 15 6 22 26 29 10 

Philippines 72 40 16 54 65 73 26 

Thailand 91 79 74 65 85 91 72 

Vietnam 84 71 59 51 78 84 43 

To estimate the breakeven $/tCO2eq of these mitigation options, DNDC results for the change from 

baseline in net emissions, yields, and fertilizer applications are used in combination with rice crop and 

fertilizer price information, as well as assumptions about other input costs and labor changes. Change in 

crop revenue is estimated with DNDC changes in yields and IFPRI’s changes in current and projected 

region-specific baseline producer prices for rice (see Appendix T). For the ammonium sulfate option, the 

additional input cost is the extra cost of ammonium sulfate compared with urea and ammonium 

bicarbonate, based on FAO prices. For the slow-release fertilizer option, the additional input cost is 

assumed to be $20 per hectare for all regions, based on the cost of using Agrotain, a urease inhibitor 

thought to be an appropriate proxy. 

No one-time capital costs are assumed for any of the rice mitigation options. Three of the options (i.e., 

midseason drainage, shallow flooding under irrigated conditions, and off-season straw amendments) are 
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V-20 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

assumed to require additional labor compared with baseline practices. The percentage increase in labor 

for these three options is assumed to be uniform across all regions and is estimated by assuming 

percentage changes in preharvest labor based on data from Moser and Barrett (2002) for systems of rice 

intensification as a rough proxy. Preharvest labor is assumed to account for 75 percent of total labor in all 

regions. GTAP data on value of inputs used in rice production are used to calculate the share of output 

value attributable to rice labor costs for each region. This share is used to calculate baseline labor costs per 

hectare from the estimated value of output per hectare by region. Labor rates are taken from IFPRI’s 

IMPACT model to calculate the implied number of labor hours per hectare, consistent with the labor cost 

per hectare, as a validity check on the labor costs being estimated. Section V.1.3.1 provides additional 

information on how these individual parameters are used to estimate costs. 

V.2.3 Livestock (CH4 and N2O) 

V.2.3.1 Livestock Enteric CH4 Emissions Characterization 

Methane is produced as part of the normal digestive process in animals. During digestion, microbes 

present in an animal’s digestive system ferment food consumed by the animal. This microbial 

fermentation process is referred to as enteric fermentation and produces CH4 as a by-product, which can 

be exhaled or eructated by the animal. The amount of CH4 produced and excreted by an animal depends 

primarily on the animal’s digestive system and the amount and type of feed it consumes. 

Ruminant animals (e.g., cattle, buffalo, sheep, goats, and camels) are the major emitters of CH4

because of their unique digestive systems. Ruminants possess a rumen, or large fore-stomach, in which 

microbial fermentation breaks down coarse plant material for digestion. Nonruminant domesticated 

animals (e.g., swine, horses, mules) also produce CH4 emissions through enteric fermentation, although 

this microbial fermentation occurs in the large intestine, where the capacity to produce CH4 is lower 

(USEPA, 2005b). 

An animal’s feed quality and feed intake also affect CH4 emissions. In general, lower feed quality or 

higher feed intake lead to higher CH4 emissions. Feed intake is positively related to animal size, growth 

rate, and production (e.g., milk production, wool growth, pregnancy, or work). Therefore, feed intake 

varies among animal types, as well as among different management practices for individual animal 

types. 

Because CH4 emissions represent an economic loss to the farmer—where feed is converted to CH4

rather than to product output—viable mitigation options can entail feed efficiency improvements to 

reduce CH4 emissions per unit of beef or milk. However, these mitigation options can actually increase

CH4 per animal. 

V.2.3.2 Livestock Manure CH4 and N2O Emissions Characterization 

The management of livestock manure can produce both CH4 and N2O emissions. Methane is 

produced by the anaerobic decomposition of manure. Nitrous oxide is produced through the nitrification 

and denitrification of the inorganic nitrogen derived from livestock manure and urine. 

When livestock and poultry manure is stored or treated in systems that promote anaerobic conditions 

(e.g., as a liquid or slurry in lagoons, ponds, tanks, or pits), the decomposition of materials in the manure 

tends to produce CH4. When manure is handled as a solid (e.g., in stacks or pits) or deposited on pasture, 

range, or paddock lands, it tends to decompose aerobically and produce little or no CH4 (USEPA, 2005b). 

Ambient temperature and manure storage or residency time also significantly affects the amount of 

CH4 produced because of influences on the growth of the bacteria responsible for CH4 formation. For 
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GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES V-21

example, CH4 production generally increases with rising temperature and residency storage time 

(USEPA, 2005b). Also, for nonliquid-based manure systems, moist conditions (which are a function of 

rainfall and humidity) favor CH4 production. Although the majority of manure is handled as a solid, 

producing little CH4, the general trend in manure management, particularly for large dairy and swine 

producers in the United States and other industrialized countries, is one of increasing use of liquid 

systems. 

The composition of the manure also affects the amount of CH4 produced. Manure composition varies 

by animal type and diet. In general, the greater the energy content of the feed, the greater the potential for 

CH4 emissions. For example, feedlot cattle fed a high-energy grain diet generate manure with a high CH4-

producing capacity, whereas range cattle fed a low-energy diet of forage material produce manure with 

about half the CH4-producing potential (USEPA, 2005b). However, some higher-energy feeds also are 

more digestible than lower quality forages, which can result in less overall waste excreted from the 

animal. 

A small portion of the total nitrogen excreted in manure and urine is expected to convert to N2O. The 

production of N2O from livestock manure depends on the composition of the manure and urine, the type 

of bacteria involved in the process, and the amount of oxygen and liquid in the manure system (USEPA, 

2005b). For N2O emissions to occur, the manure must first be handled aerobically where NH3 or organic 

nitrogen is converted to nitrates and nitrites (nitrification) and then handled anaerobically, where the 

nitrates and nitrites are reduced to nitrogen gas (N2), with intermediate production of N2O (i.e., 

denitrification) (Groffman et al., 2000). These emissions are most likely to occur in dry manure handling 

systems that have aerobic conditions but that also contain pockets of anaerobic conditions, such as rain 

events. 

V.2.3.3 The USEPA Baseline Estimates of Livestock Enteric CH4 Emissions 

Baseline emissions of and activity data for livestock enteric CH4 are taken directly from USEPA 

(2006). Enteric CH4 emissions from livestock are estimated to be the second largest source of global 

agricultural non-CO2. In 2000, global enteric CH4 emissions were estimated to be 85,648 Gg or 1,799 

MtCO2eq and are projected to increase more than 30 percent by 2020 to 111,633 Gg or 2,344 MtCO2eq (a 

32 percent increase relative to 1990). Livestock enteric CH4 accounted for 32 percent of global agricultural 

non-CO2 emissions in 2000. In the United States, enteric CH4 accounts for 27 percent of agricultural nonCO2 and less than 2 percent of all greenhouse gas emissions (USEPA, 2005b). 

V.2.3.4 The USEPA Baseline Estimates of Livestock Manure CH4 and N2O Emissions 

Baseline emissions of and activity data for livestock manure CH4 and N2O are taken directly from 

USEPA (2006). The joint CH4 and N2O emissions from livestock manure are estimated to be the fourth 

largest source of global agricultural non-CO2 emissions. In 2000, livestock manure emissions were 

estimated to be 421 MtCO2eq, or 10,732 Gg of CH4 and 632 Gg of N2O, and are projected to increase 24 

percent by 2020 to 523 MtCO2eq, or 12,832 Gg of CH4 and 818 Gg of N2O (a 21 percent increase relative to 

1990). Livestock manure emissions accounted for less than 8 percent of global agricultural non-CO2

emissions in 2000. In the United States, joint CH4 and N2O emissions from livestock manure account for 

13 percent of agricultural non-CO2 emissions and less than 1 percent of all greenhouse gas emissions 

(USEPA, 2005b). 

V.2.3.5 Mitigation Options for Livestock Emissions 

Non-CO2 greenhouse gas emissions from livestock can be reduced primarily through either reducing 

CH4 emissions that occur during the normal digestive process (i.e., enteric fermentation) or capturing 
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V-22 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

CH4 emitted by livestock manure. There is also potential to affect N2O emissions from manure 

management, either indirectly through options that target CH4, but also through mitigation options that 

primarily target N2O. However, limited quantitative information is available on the co-effects of CH4

mitigation options on N2O or the cost or emissions reductions associated with options focused on N2O. 

Thus, the focus here is on options designed to reduce CH4 but to account for changes in N2O emissions 

for those options that change livestock populations by assuming a change in N2O emissions 

proportionate to the change in livestock population. 

V.2.3.5.1 Mitigation Options for Livestock Enteric CH4

The enteric CH4 mitigation options fall into four general categories: (1) improvements to food 

conversion efficiency by increasing energy content and digestibility of feed, (2) increased animal 

productivity through the use of natural or synthetic compounds that enhance animal growth and/or 

lactation (e.g., bovine somatotropin [bST], antibiotics), (3) feed supplementation to combat nutrient 

deficiencies that prevent animals from optimally using the potential energy available in their feed, and (4) 

changes in herd management (e.g., use of intensive grazing).10 Some of these proposed options for enteric 

fermentation may actually increase net greenhouse gas emissions per animal but lead to an even larger 

increase in productivity. Thus, emissions per unit of product (e.g., meat, milk, or work) decline, and 

mitigation at the national or regional level requires a sufficient reduction in the number of animals to 

more than offset the increase in emissions per animal. To capture this issue, two separate estimates of 

mitigation potential and costs were developed assuming both a constant number of animals and constant 

production. The static, engineering approach does not allow for simultaneous adjustment in both number 

of animals and production; however, sensitivity experiments at the end of this section using the global 

agricultural commodity market model, IMPACT, allow for these dynamic feedbacks to occur. 

Table 1-8 summarizes the enteric fermentation options. Most of these options could also be applied to 

other livestock species (e.g., buffalo, sheep, goats), but no data were available on the emissions reductions 

or productivity effects that would be expected for those species. 

V.2.3.5.2 Mitigation Options for Livestock Manure CH4 and N2O 

All manure CH4 mitigation options involve the capture and use of CH4 through anaerobic digesters. 

Anaerobic digesters are currently in limited use on large-scale livestock operations in developed regions, 

often primarily as a means of treating and stabilizing waste and controlling odor, but the CH4 that is 

captured is also used as an energy source. Small-scale, ambient temperature digesters are also being used 

in developing regions, such as China, India, and Vietnam, for household energy generation. The 

feasibility of digesters depends in part on climate. There are a large number of different types of digesters 

that can be used, with some being more appropriate for certain climates or livestock species than others. 

Another important characteristic of digester systems is whether they include engines for electricity 

generation. Systems generating electricity can potentially create savings by offsetting farm purchases of 

electricity or even selling the electricity. Systems that do not include electricity generation generally use 

the heat generated for on-farm use to offset purchases of heating fuels. 

 

10 Emissions can also be mitigated through other methods, such as improving genetic characteristics, feeding 

compounds that inhibit rumen methane formation, improving reproduction efficiency, and controlling disease better. 

However, data are currently insufficient to include estimates for these options. 
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GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES V-23

Table 1-8: Livestock Enteric Fermentation Greenhouse Gas Mitigation Options 

Mitigation Option Description 

Greenhouse Gas 

Effectsa

Improved feed 

conversion 

Increase the amount of grain fed to livestock to increase the 

proportion of feed energy being converted to milk, meat, or work 

instead of animal maintenance. This option tends to increase 

emissions per animal but reduce emissions per unit output. It is 

more effective in reducing emissions per unit of production in 

regions where baseline feed is of relatively low quality. This option 

is applied to both beef and dairy cattle in all regions, although it 

was excluded from the MACs for some developed regions where it 

resulted in slightly higher GHG emissions. 

CH4, some N2O 

Antibiotics Administer antibiotics (e.g., monensin) to beef cattle to promote 

faster weight gain, which reduces time to maturity and CH4

production per kilogram of weight gain. This option is applied in all 

regions. 

CH4, some N2O 

Bovine somatotropin 

(bST) 

Administer bST to dairy cattle to increase milk production. In many 

cases, this option increases CH4 emissions per animal but 

typically increases milk production sufficiently to lower emissions 

per kilogram of milk. Because of opposition to the use of bST in 

many countries, this option was only applied in selected countries 

that currently approve of the use of bST or are likely to approve its 

use by 2010. 

CH4, some N2O 

Propionate precursors Involves administering propionate precursors to animals on a daily 

basis. Hydrogen produced in the rumen through fermentation can 

react to produce either CH4 or propionate. By adding propionate 

precursors to animal feed, more hydrogen is used to produce 

propionate and less CH4 is produced. This option is applied to 

both beef and dairy cattle in all regions. 

CH4, some N2O 

Antimethanogen Vaccine in development by Commonwealth Scientific and 

Industrial Research Organization (CSIRO) that can be 

administered to animals and will suppress CH4 production in the 

rumen. This option is applied to beef and dairy cattle, sheep, and 

goats in all regions. 

CH4, some N2O 

Intensive grazing Moving to a more management-intensive grazing system where 

cattle are frequently rotated between pastures to allow recently 

grazed pastures time to regrow and to provide cattle with more 

nutritious pasture grazing that will permit replacement of more 

feed grains. This option may actually reduce animal yields but will 

decrease emissions by an even larger percentage. This option is 

applied to beef and dairy cattle in developed regions and Latin 

America. 

CH4, some N2O 

a For this analysis, effects on N2O are estimated only for the scenarios where production is held constant and there is a change in livestock 

population. 
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V-24 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

The types of digesters are aggregated based on a categorization of representative systems provided 

by the USEPA’s AgStar program (Table 1-9). For most regions, swine and diary cattle account for the 

majority of greenhouse gas emissions from manure, largely because their manure is often managed in 

liquid systems under anaerobic conditions. Although CH4 emissions from manure could potentially be 

captured from additional species (e.g., beef cattle, buffalo, sheep, goats), these species typically account 

for much smaller shares of emissions and are often managed on pasture much of the year with solid 

manure handling. Manure from livestock on pasture does not produce much CH4 because it decomposes 

under aerobic conditions, resulting in little to no emissions. Based on IPCC default factors, the CH4

emissions factor is actually higher for digesters than for dry manure management systems such as 

pasture. 

Complete-mix, plug-flow, fixed-film, and large-scale covered lagoon digesters are applied only in the 

United States, EU-15, Japan, Australia, other developed countries, Eastern Europe, Central Asia, FSU, 

China, South Korea, and other East Asian regions, based on climate, environmental regulations, capital 

costs, and other considerations. The dome, polyethylene bag, small-scale covered lagoon, and flexible-bag 

digesters are applied in all other world regions. China and other parts of East Asia are the only regions 

where digesters in both of these groups are applied. Applicability of these options was further refined by 

allocating the share of baseline emissions to swine and dairy cattle and applying emissions reductions 

only to those portions of the emissions stream. The share of livestock manure emissions due to dairy and 

swine is based on USEPA (2006), which relies on both IPCC inventory default methodologies and 

individual country greenhouse gas inventory reports. 

CH4 reduction efficiencies are assumed to be 85 percent from baseline for the complete-mix, plugflow, fixed-film, and large-scale covered lagoon digesters based on the difference between IPCC default 

emissions factors for anaerobic manure management, where CH4 is released into the atmosphere, and 

digesters. For the smaller-scale digesters applied in developing countries, the reduction efficiency is 

assumed to be 50 percent from baseline, where baseline emissions are much lower because of a different 

distribution of manure management practices and the likelihood of less efficient CH4 capture. 

Capital costs are taken from the USEPA’s AgStar program (Roos, personal communication, 2005), 

which estimates the capital cost per 1,000 pounds of liveweight. These values are combined with the 1996 

IPCC guideline values for average liveweight for different species in regions around the world to 

generate estimates of the capital cost per animal. Because liveweight per animal tends to be much smaller 

in developing countries, the capital cost per animal ends up being lower than in developed regions. This 

cost is annualized assuming that the large-scale digesters have an expected useful lifetime of 20 years and 

the small-scale digesters have an expected useful lifetime of 10 years. 

GTAP data on labor cost shares by region for livestock production and IMPACT data on regional 

agricultural wage rates are used to calculate the baseline labor hours per animal and change in hours to 

verify the reasonableness of these assumptions, as described above for cropland soil management and 

rice cultivation. For large-scale digesters, labor requirements for swine farms are assumed to increase by 2 

percent for options without engines and 4 percent for those with engines. For dairy farms, labor 

requirements are assumed to increase by 0.5 percent for options without engines and 1 percent for those 

with engines. The percentage increase in labor is smaller, because dairy farming is already much more 

labor intensive and requires much more labor per animal in the baseline. The increase in labor for dairy 

farms is calculated by assuming 200 hours per year in the United States for digester operation, repairs, 

management, and typical farm size of 800 cows with 50 hours of labor per head per year in the baseline. 

For hog farms, it is again assumed that a digester will add about 200 hours of labor per year, but 

assuming an average of about 5,000 hogs per farm per year, that assumption could potentially add a 
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GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES V-25

Table 1-9: Livestock Manure Management Greenhouse Gas Mitigation Options 

Mitigation Option Description 

Greenhouse Gas 

Effectsa

Complete-mix 

digester 

These digesters are more common in warmer climates, where manure 

is flushed out of barns or pens with water, lowering the solids’ 

concentration to a level generally between 3 percent and 10 percent. 

Often there is a mixing tank where the manure accumulates before 

entering the digester. These digesters make use of gravity and pumps 

to move the manure through the system. They are often in the shape 

of a vertical cylinder and made of steel or concrete with a gas-tight 

cover. These digesters are typically heated to maintain a constant 

temperature and constant gas flow. 

CH4

Plug-flow digester These digesters consist of long and relatively narrow heated tanks, 

often built below ground level, with gas-tight covers. Plug-flow 

digesters are only used for dairy manure because they require higher 

manure solids’ content, around 11 percent to 13 percent. As with 

complete-mix digesters, they are maintained at constant temperatures 

throughout the year to maintain consistent gas production. 

CH4

Fixed-film digester This digester option may be appropriate where concentrations of 

solids are very low, such as in manure management situations where 

manure is very diluted with water. Fixed-film digesters consist of a 

tank packed with inert media on which bacteria grow as a biofilm. 

CH4

Covered lagoon 

digester, large-scale 

Covered earthen lagoons are the simplest of the systems used in 

developed countries and generally the least expensive, though there 

is quite a bit of variation in the systems that have been built. This 

system is used with low manure solids’ concentration (less than 3 

percent) and can be used for swine or dairy cattle. CH4 is captured by 

covering the lagoon where manure is stored with a floating cover and 

piping the gas out to a flare or used on-farm. Because these digesters 

are not generally heated, the available gas flow varies significantly 

over the course of the year. 

CH4

Dome digester, 

cooking fuel and 

light 

These are small-scale, unheated digesters used in some developing 

nations, including China and India. A typical dome digester is a bricklined cylinder sunk in the ground with a wall dividing the cylinder in 

two with inlet and outlet ports connected to the bottom of the tank. 

Biogas generated is typically used by the household for cooking and 

other household energy needs. 

CH4

Polyethylene bag 

digester, cooking 

fuel and light 

This small-scale unheated digester is in use in a variety of developing 

countries. The digester essentially consists of a hole dug in the 

ground and covered with a plastic bag, with an area for input of 

manure and a pipe with a valve for biogas produced. Biogas 

generated is typically used by the household for cooking and other 

household energy needs. 

CH4

Covered lagoon, 

small-scale, for 

cooking fuel, light, 

shaft power 

This is smaller-scale and much cheaper version of the covered lagoon 

above, used to generate biogas for household use. Some of these 

digesters may produce enough energy for shaft power, in addition to 

household cooking and other uses. 

CH4

Flexible-bag 

digester, cooking 

fuel and light 

This is another relatively simple and low-cost unheated digester used 

in developing countries where the biogas is generated and collected 

within a plastic bag. 

CH4

a Unlike options for reducing emissions from enteric fermentation, none of the options included for manure management are expected to affect 

yields and there are no effects on N2O currently being estimated. 
SECTION V — AGRICULTURE • EMISSIONS CHARACTERIZATION, BASELINES, AND MITIGATION SCENARIOS 

V-26 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

digester and about 2 hours of labor per hog annually in the baseline. Options with engines and 

accompanying electricity generation and transfer equipment were assumed to require twice as much 

labor as those that produce heat only. For the small-scale digesters in developing nations, labor was 

assumed to increase by 2.5 percent for options without engines and 5 percent for those with engines that 

rely on manure from either swine or dairy cattle. Many of these digesters are used on operations with 

only a few animals and often combine manure from multiple species with other household wastes. 

None of these manure management options are expected to change livestock yields. Revenues (or 

cost savings) are generated from using captured CH4 (essentially natural gas) for either heat or electricity 

on the farm. Revenues are scaled for other non-U.S. regions based on a U.S. Energy Information Agency 

(USEIA) electricity price index (2003). 

Breakeven prices ($/tCO2eq) for these mitigation options are calculated by region and by species 

using the emissions reductions from baseline, annualized capital costs, changes in labor costs, and energy 

savings or revenue. Section V.1.3.1 provides additional information on how these individual parameters 

are used to estimate costs. 

V.2.3.6 Changes in Livestock CH4 and Productivity 

Figure 1-3 shows total livestock emissions (enteric fermentation and manure management) associated 

with the baseline and mitigation scenarios, assuming a constant number of animals, where each option is 

assumed to be applied to 100 percent of the appropriate livestock species (see Tables 1-8 and 1-9), and 

appropriate regions. Similarly, Figure 1-4 shows the relative emissions under baseline and the mitigation 

scenarios, assuming constant production. Because percentage emissions reductions are assumed to be the 

same across all large-scale digesters and across all small-scale digesters, the individual manure 

management mitigation options identified in Table 1-9 are aggregated here. 

Figure 1-3: Global Net Greenhouse Gas (CH4 and N2O) Livestock Emissions under Baseline and 

Mitigation Scenarios, Assuming Full Adoption of Individual Options and Holding Number of 

Animals Constant 

0

500

1,000

1,500

2,000

2,500

3,000

3,500

2000 2010 2020

Year

MtCO2eq

Baseline Improved feed conversion Antibiotics

bST Propionate precursors Antimethanogen

Intensive grazing Large-scale digesters Small-scale digesters
SECTION V — AGRICULTURE • EMISSIONS CHARACTERIZATION, BASELINES, AND MITIGATION SCENARIOS 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES V-27

Figure 1-4: Global Net Greenhouse Gas (CH4 and N2O) Livestock Emissions under Baseline and 

Mitigation Scenarios, Assuming Full Adoption of Individual Options and Holding Production 

Constant 

Because some of the enteric fermentation options increase yields in many regions, holding production 

of meat and milk constant means that there will be fewer animals needed for production. Thus, emissions 

tend to fall more under the constant production assumption than the constant animals assumption. For 

instance, improved feed conversion has such large positive yield impacts that emissions under full 

adoption of that option are about 250 MtCO2eq less annually when holding production constant and 

reducing the number of livestock, than when the number of animals is held constant. Section V.1.3.6 

presents results that reflect adjustments for market impacts where there are simultaneous changes in the 

number of animals and in production. In practice, a combination of mitigation options would be adopted 

and no single option would be adopted for all production. In Section V.1.3.4, MACs are presented that 

assume partial adoption of each of the available options in each region. However, Figures 1-3 and 1-4 are 

included to give a sense of the relative emissions that would occur under different production scenarios. 

Holding the number of animals constant, emissions are lowest under intensive grazing, followed by 

propionate precursors, antimethanogen, large-scale digesters, improved feed conversion, small-scale 

digesters, antibiotics, and bST. However, when production is held constant, the order differs, with 

improved feed conversion followed by propionate precursors, antimethanogen, intensive grazing, largescale digesters, antibiotics, small-scale digesters, and bST. 

As mentioned above, an important component of these options that will influence net emissions is the 

change in yield corresponding to each of these options. For some options (e.g., improved feed 

conversion), the yield effects vary substantially across regions because of widely differing baseline 

conditions. To summarize the primary overall yield effects, Figures 1-5 and 1-6 show the difference in 

global production of beef and milk from dairy cattle under full adoption of each of these options, holding 

the number of animals constant. 

0

500

1,000

1,500

2,000

2,500

3,000

3,500

2000 2010 2020

Year

MtCO2eq

Baseline Improved feed conversion Antibiotics

bST Propionate precursors Antimethanogen

Intensive grazing Large-scale digesters Small-scale digesters
SECTION V — AGRICULTURE • EMISSIONS CHARACTERIZATION, BASELINES, AND MITIGATION SCENARIOS 

V-28 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

Figure 1-5: Global Beef Production under Baseline and Mitigation Options, Assuming Full Adoption of 

Individual Options and Holding the Number of Animals Constant 

Figure 1-6: Global Production of Milk from Dairy Cattle under Baseline and Mitigation Options, 

Assuming Full Adoption of Individual Options and Holding the Number of Animals Constant 

0

20

40

60

80

100

2000 2010 2020

Year

Million MT

Baseline Improved feed conversion Antibiotics

Propionate precursors Antimethanogen Intensive grazing

Large-scale digesters Small-scale digesters

100

200

300

400

500

600

700

800

900

2000 2010 2020

Year

Million MT

Baseline Improved feed conversion bST

Propionate precursors Antimethanogen Intensive grazing

Large-scale digesters Small-scale digesters
SECTION V — AGRICULTURE • EMISSIONS CHARACTERIZATION, BASELINES, AND MITIGATION SCENARIOS 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES V-29

For both beef and milk from dairy cattle, the largest yield increases are for improved feed conversion 

in 2000. Yield increases relative to baseline are smaller in future years, largely because productivity is 

improving rapidly under the baseline.11 Improved feed conversion remains the option with the largest 

average global yield improvement for beef production in all years. Antibiotics, propionate precursors, 

and antimethanogen all increase beef yield by a similar amount, while intensive grazing, large-scale 

digesters, and small-scale digesters are assumed to have no impact on beef yield. For milk yield, 

propionate precursors and antimethanogen lead to similar increases in yield, which become greater than 

improved feed conversion by 2010. The use of bST leads to a small increase in yield, which would be 

larger were it not for assumptions that many regions will not adopt this option. Large-scale and smallscale digesters are assumed to have no impact on milk yield. Intensive grazing has a negative effect on 

milk yield. 

 

11 The percentage increase in yield attributable to the mitigation option for improved feed conversion is calculated 

for each year by netting out the percentage increase in baseline yield projected by IMPACT. This is done to reflect 

improved practices expected to be adopted in the baseline and avoid double-counting improvements in yield. 
SECTION V — AGRICULTURE • EMISSIONS CHARACTERIZATION, BASELINES, AND MITIGATION SCENARIOS 

V-30 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 
SECTION V — AGRICULTURE • RESULTS 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES V-31

V.3 Results 

V.3.1 Estimating Average Costs and Constructing Abatement Curves 

The methods used to estimate the average cost of each mitigation option and construct the MACs in 

the agricultural sector follow the general methodology described in Section I. This section shows 

additional baseline emissions data (as described in Section V.1.2), the average costs of the mitigation 

options for key countries, and the MACs for key countries and world totals. 

The average cost for each mitigation option represents the present-value breakeven price, expressed 

as 2000$ t/CO2eq, where total benefits equal total costs. The $/tCO2eq is estimated according to 

( )( ) ( )

( )

( )

( ) ¦ ¦ = =

»

1⁄4

o «

¬

a

+

− » = +

1⁄4

o «

¬

a

+

× − + − + T

t t

T

t t DR

RC TR CC

DR

P ER TR R TR TB

1

0

1 1

1

1

1 1

(1.1) 

where 

P = The breakeven price of the option in dollars per metric ton of CO2 equivalent ($/tCO2eq). 

ER = The emissions reduction achieved by the technology (MtCO2eq). 

R = The revenue generated from energy production (scaled based on regional energy prices) or 

change in agricultural commodity prices ($). 

T = The option lifetime (years). 

DR = The selected discount rate (10%). 

CC = The one-time capital cost of the option ($). 

RC = The recurring (operation and maintenance [O&M]) cost of the option (portions of which may 

be scaled based on regional labor costs) ($/year). 

TR = The tax rate (40%). 

TB = The tax break equal to the capital cost divided by the option lifetime, multiplied by the tax rate 

($). 

Assuming that the emissions reduction, ER, the recurring costs, RC, and the revenue generated R do 

not change on an annual basis, then we can rearrange this equation to solve for the breakeven price, P, of 

the option for a given year as follows: 

(1 )

(1 )

1 (1 )

1

TR

TR

ER T

CC

ER

R

ER

RC

DR

TR ER

CC P T

t

t

− ⋅ ⋅ + − −

+ −

=

¦=

 (1.2) 

The cost estimate takes into account greenhouse gas reductions, revenue effects (e.g., positive or 

negative changes in yield), any required capital costs (e.g., anaerobic digesters), labor requirements, and 

changes in other input costs (e.g., increase or decrease in fertilizer applications), all relative to baseline 

conditions. Section V.1.2 above describes the individual mitigation options; the methods for estimating 

their associated effects on greenhouse gas emissions and yields; and the assumptions used for other 

input, capital, and labor costs. 

MACs showing greenhouse gas reductions, in terms of percentage reductions from the baseline in 

2010 and 2020, are estimated for key regions and world totals. Emphasis is placed on percentage 

reductions from the baseline, rather than on absolute emissions reduction numbers, because the overall 
SECTION V — AGRICULTURE • RESULTS 

V-32 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

trends are most important to convey for this analysis. Furthermore, the baselines for croplands and rice 

cultivation are not comprehensive greenhouse gas inventory estimates so that the percentage changes 

from these baselines are viewed as more transferable to other kinds of analyses. 

To construct the MAC, lines are essentially drawn to connect the points representing the average cost 

of each mitigation option (where the X axis is MtCeq mitigated and the Y axis is $/tCO2eq). The following 

general factors are estimated to ensure the MAC can represent simultaneous adoption of all mitigation 

options. First, a technical applicability fraction is estimated to ensure the mitigation option is applied only 

to the correct portion of baseline emissions. For example, options to reduce dairy cattle emissions can 

only be applied to the fraction of livestock emissions attributable to dairy cattle. Second, an implied 

adoption rate is estimated by segmenting the applicable baseline emissions into uniform fractions based 

on the number of mitigation options. For example, if 10 mitigation options could technically be applied to 

reduce cropland N2O emissions, then each mitigation option is assumed to apply to only 10 percent of 

baseline emissions. This is a simplistic method to avoid double counting among mitigation options, but 

unfortunately it does not allow lower-cost options to out-compete higher-cost options. Other factors in 

addition to cost (e.g., adoption feasibility and implementation barriers) can of course determine the extent 

to which one mitigation option is adopted over another. Because such factors are not included, this static 

approach of allowing each mitigation option to be applied equally is viewed as a conservative approach 

to estimate the technical mitigation potential. 

All mitigation options are assumed to be implemented immediately (i.e., in the first data year, 2000), 

but only for appropriate regions, and are assumed to remain in place continuously until 2020. Therefore, 

the MACs presented in 2010 represent the emissions reductions and associated costs that occur in year 

2010, assuming that all mitigation options have been implemented since 2000. The emissions reductions 

represented in 2010 are estimated relative to the 2010 emissions baseline under the assumption that no 

mitigation options have been implemented since 2000. 

Two general approaches are used to calculate all MACs in the agricultural sector. The first approach 

keeps cropland area, rice area, and livestock populations constant over time, allowing total production to 

change as yields per hectare and productivity per animal change as a result of the mitigation options. The 

biophysical modeling in DAYCENT and DNDC also holds land area constant over time. The second 

approach holds crop production, rice production, and livestock production (e.g., production of milk and 

beef) constant over time, allowing land area and animal populations to change (postprocess). In this case, 

land area is changed for each region by scaling the revised per-hectare yield numbers to maintain the 

same regional crop or rice production as in the baseline. Livestock population numbers are changed in a 

similar way. This latter approach is particularly important for the livestock sector, because many 

proposed enteric fermentation mitigation options actually increase CH4 emissions per animal but decrease 

CH4 emissions per unit product. Results are shown for both approaches. 

V.3.2 Baselines, Mitigation Costs and MACs for Croplands 

Table 1-10 presents the baseline net GHG emissions (N2O and soil carbon) from croplands 

management by region by year used in this analysis. These are the values to which all estimated 

percentage reductions in croplands emissions were applied. 
SECTION V — AGRICULTURE • RESULTS 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES V-33

Table 1-10: Baseline Net GHG Emissions from Croplands from DAYCENT Estimates (MtCO2eq) 

Country/Region 2000 2010 2020 

Africa 29 32 36 

Annex I 508 484 521 

Australia/New Zealand 13 17 17 

Brazil 27 30 30 

China 91 97 104 

Eastern Europe 38 39 41 

EU-15 91 93 101 

India 66 69 73 

Japan 0 0 0 

Mexico 14 16 28 

Non-OECD Annex I 171 123 124 

OECD 313 338 373 

Russian Federation 171 123 124 

South & SE Asia 25 26 28 

United States 167 179 200 

World Total 839 830 893 

EU-15 = European Union; OECD = Organisation for Economic Co-operation and Development. 

Note: These emissions include only croplands used for wheat, maize, or soybean production. 

Note: Combinations of countries included in regions available from DAYCENT are not identical to those included in regions presented in this 

report, but were aggregated to approximate these regions as closely as possible. 

Table 1-11 shows information on the yield effects, emissions reductions, and costs associated with 

individual croplands mitigation options for the United States, EU-15, Brazil, China, and India. 

Table 1-12 provides estimates of the percentage reduction in net GHG emissions (relative to the 

croplands baseline used in this analysis) that could potentially be achieved at prices between $0/tCO2eq 

and $60/tCO2eq for both 2010 and 2020 in major regions around the world. 

Figure 1-7 shows the globally aggregated MAC for cropland greenhouse gas mitigation for 2000, 

2010, and 2020, in terms of percentage emissions reductions from baseline over the applicable carbon 

price range. With no price signal (i.e., at $0/tCO2eq), approximately 15 percent of cropland net GHG (N2O 

and soil carbon) can be mitigated. More than 190 million tCO2eq (about 22 percent to 23 percent of 

baseline emissions, depending on which year is analyzed) are mitigated at less than $45/tCO2eq in 2010 

and 2020, but costs begin to rise rapidly beyond that point. Mitigation levels do not substantially increase 

at higher prices, given the mitigation options considered here. 

Negative costs result from options with cost savings because of lower applications of fertilizers while 

maintaining yields, whereas high-cost options are those where revenues decline as yields decline in 

response to suboptimal fertilizer applications. Negative cost options are consistent with previous studies, 

finding large potential agricultural mitigation from “no-regret” options. The fact that farmers are not 

adopting options that seemingly would increase profitability indicates that this analysis may not capture 

some costs barriers to adoption exist, such as increased variability of profits or complexity of 

management requirements. 
SECTION V — AGRICULTURE • RESULTS 

V-34 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES Table 1-11: Croplands Mitigation Option Detail for Key Regions United States EU-15 Brazil Croplands Change in Output Yield (% from baseline) Breakeven Cost ($/tCO2eq) Emissions Reduction (Absolute, MtCO2eq) Emissions Reduction (% from baseline) Change in Output Yield (% from baseline) Breakeven Cost ($/tCO2eq) Emissions Reduction (Absolute, MtCO2eq) Emissions Reduction (% from baseline) Change in Output Yield (% from baseline) Breakeven Cost ($/tCO2eq) Emissions Reduction (Absolute, MtCO2eq) Emissions Reduction (% from baseline) Nitrogen inhibitor—wheat–rf 6.6% $26 2.33 1.3% 9.6% –$13 2.568 2.8% 11.7% $27 0.029 0.1% Nitrogen inhibitor—wheat–irri 7.4% $11 0.17 0.1% 10.0% –$18 1.107 1.2% 11.9% $25 0.000 0.0% Nitrogen inhibitor—maize–rf 3.6% $9 2.99 1.7% 2.7% $15 0.171 0.2% 25.5% $21 1.180 4.0% Nitrogen inhibitor—maize–irri 3.4% $2 0.58 0.3% 2.3% $13 0.061 0.1% NA NA NA NA Nitrogen inhibitor—soybean–rf 0.6% $210 0.53 0.3% 0.4% $384 0.001 0.0% 2.4% $125 0.231 0.8% Nitrogen inhibitor—soybean–irri 0.5% $210 0.05 0.0% 0.3% $323 0.000 0.0% NA NA NA NA Split fertilization—wheat–rf 8.6% –$64 2.00 1.1% 2.7% $48 0.542 0.6% 19.8% –$69 0.039 0.1% Split fertilization—wheat–irri 8.3% –$67 0.14 0.1% 3.0% $44 0.214 0.2% 19.3% –$70 0.000 0.0% Split fertilization—maize–rf 9.4% –$38 7.59 4.2% 3.8% $13 0.154 0.2% 11.4% –$60 0.173 0.6% Split fertilization—maize–irri 8.9% –$38 1.60 0.9% 4.3% $5 0.077 0.1% NA NA NA NA Split fertilization—soybean–rf 1.0% $188 0.33 0.2% 0.0% $190,338 0.000 0.0% 0.6% $76 0.081 0.3% Split fertilization—soybean–irri 0.8% $298 0.03 0.0% 0.0% $366,480 0.000 0.0% NA NA NA NA Reduce fertilizer to 70% of base— wheat–rf –16.6% $267 0.81 0.5% –19.1% $114 0.798 0.9% –12.2% $69 0.008 0.0% Reduce fertilizer to 70% of base— wheat–irri –16.3% $296 0.06 0.0% –19.0% $170 0.260 0.3% –12.2% $76 0.000 0.0% Reduce fertilizer to 70% of base— maize–rf –23.6% –$613 –1.12 –0.6% –15.9% –$22,944 –0.001 0.0% –23.7% $109 –0.062 –0.2% Reduce fertilizer to 70% of base— maize–irri –22.7% –$553 –0.28 –0.2% –15.4% –$445 –0.018 0.0% NA NA NA NA Reduce fertilizer to 70% of base— soybean–rf –0.6% –$44 0.33 0.2% 0.0% –$64 0.000 0.0% –0.5% –$14 0.088 0.3% Reduce fertilizer to 70% of base— soybean–irri –0.5% –$43 0.03 0.0% 0.0% –$40 0.000 0.0% NA NA NA NA Reduce fertilizer to 80% of base— wheat–rf –11.0% $249 0.57 0.3% –13.0% $117 0.553 0.6% –8.1% $70 0.005 0.0% Reduce fertilizer to 80% of base— wheat–irri –10.9% $293 0.04 0.0% –12.9% $174 0.176 0.2% –8.2% $76 0.000 0.0% Reduce fertilizer to 80% of base— maize–rf –15.8% –$766 –0.60 –0.3% –10.4% $1,231 0.010 0.0% –16.3% $71 –0.057 –0.2% Reduce fertilizer to 80% of base— maize–irri –15.2% –$628 –0.17 –0.1% –10.3% –$635 –0.009 0.0% NA NA NA NA Reduce fertilizer to 80% of base— soybean–rf –0.4% –$45 0.22 0.1% 0.0% –$57 0.000 0.0% –0.4% –$14 0.059 0.2% (continued) 
SECTION V — AGRICULTURE • RESULTS 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES V-35 Table 1-11: Croplands Mitigation Option Detail for Key Regions (continued) United States EU-15 Brazil Croplands Change in Output Yield (% from baseline) Breakeven Cost ($/tCO2eq) Emissions Reduction (Absolute, MtCO2eq) Emissions Reduction (% from baseline) Change in Output Yield (% from baseline) Breakeven Cost ($/tCO2eq) Emissions Reduction (Absolute, MtCO2eq) Emissions Reduction (% from baseline) Change in Output Yield (% from baseline) Breakeven Cost ($/tCO2eq) Emissions Reduction (Absolute, MtCO2eq) Emissions Reduction (% from baseline) Reduce fertilizer to 80% of base— soybean–irri –0.3% –$45 0.02 0.0% 0.0% –$46 0.000 0.0% NA NA NA NA Reduce fertilizer to 90% of base— wheat–rf –5.6% $264 0.28 0.2% –6.5% $116 0.284 0.3% –4.1% $69 0.003 0.0% Reduce fertilizer to 90% of base— wheat–irri –5.4% $275 0.02 0.0% –6.5% $174 0.090 0.1% –4.1% $74 0.000 0.0% Reduce fertilizer to 90% of base— maize–rf –7.9% –$1,037 –0.22 –0.1% –5.1% $606 0.009 0.0% –8.4% $50 –0.035 –0.1% Reduce fertilizer to 90% of base— maize–irri –7.6% –$759 –0.07 0.0% –5.1% –$941 –0.003 0.0% NA NA NA NA Reduce fertilizer to 90% of base— soybean–rf –0.2% –$47 0.11 0.1% 0.0% –$65 0.000 0.0% –0.2% –$15 0.029 0.1% Reduce fertilizer to 90% of base— soybean–irri –0.1% –$46 0.01 0.0% 0.0% –$40 0.000 0.0% NA NA NA NA Convert coventional tillage to no- till—wheat–rf 1.5% –$63 2.10 1.2% 1.2% $17 –7.160 –7.7% 0.6% –$24 0.015 0.0% Convert coventional tillage to no- till—wheat–irri 0.9% –$80 0.11 0.1% 0.3% $12 –3.977 –4.3% 0.4% –$24 0.000 0.0% Convert coventional tillage to no- till—maize–rf 1.6% –$87 4.14 2.3% 0.1% $135 –0.221 –0.2% 0.5% –$15 0.369 1.3% Convert coventional tillage to no- till—maize–irri 0.9% –$89 0.61 0.3% –2.5% $40 –0.137 –0.1% NA NA NA NA Convert coventional tillage to no- till—soybean–rf 0.2% –$154 1.37 0.8% 0.5% –$317 0.005 0.0% 0.1% –$103 0.237 0.8% Convert coventional tillage to no- till—soybean–irri 0.3% –$46 0.12 0.1% 0.6% –$135 0.001 0.0% NA NA NA NA EU-15 = European Union; NA = Data unavailable. (continued) 
SECTION V — AGRICULTURE • RESULTS 

V-36 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES Table 1-11: Croplands Mitigation Option Detail for Key Regions (continued) China India Cropland Change in Output Yield (% from baseline) Breakeven Cost ($/tCO2eq) Emissions Reduction (Absolute, MtCO2eq) Emissions Reduction (% from baseline) Change in Output Yield (% from baseline) Breakeven Cost ($/tCO2eq) Emissions Reduction (Absolute, MtCO2eq) Emissions Reduction (% from baseline) Nitrogen inhibitor—wheat–rf 5.0% $58 0.282 0.3% 2.5% $208 0.070 0.1% Nitrogen inhibitor—wheat–irri 5.6% $31 1.051 1.1% 3.9% $84 0.519 0.8% Nitrogen inhibitor—maize–rf 2.2% $49 0.788 0.8% 26.0% $9 2.513 3.6% Nitrogen inhibitor—maize–irri 2.3% $39 0.569 0.6% 24.2% $10 0.694 1.0% Nitrogen inhibitor—soybean–rf 0.3% $175 0.074 0.1% 5.6% $85 0.129 0.2% Nitrogen inhibitor—soybean–irri 0.2% $147 0.076 0.1% 5.4% $94 0.010 0.0% Split fertilization—wheat–rf 3.6% –$1 0.102 0.1% 2.3% $21 0.027 0.0% Split fertilization—wheat–irri 4.1% –$14 0.405 0.4% 3.6% –$5 0.335 0.5% Split fertilization—maize–rf 1.7% $51 0.340 0.3% 12.7% –$24 0.848 1.2% Split fertilization—maize–irri 1.8% $32 0.381 0.4% 12.7% –$34 0.219 0.3% Split fertilization—soybean–rf 0.3% $534 0.018 0.0% 0.0% $0 — 0.0% Split fertilization—soybean–irri 0.3% $449 0.025 0.0% 0.0% $0 — 0.0% Reduce fertilizer to 70% of base—wheat–rf –11.5% $30 0.321 0.3% –8.6% $7 0.193 0.3% Reduce fertilizer to 70% of base—wheat–irri –13.4% $104 0.643 0.7% –13.6% $208 0.282 0.4% Reduce fertilizer to 70% of base—maize–rf –16.0% –$226 –0.479 –0.5% –7.9% $41 0.255 0.4% Reduce fertilizer to 70% of base—maize–irri –15.7% –$206 –0.424 –0.4% –8.2% $53 0.082 0.1% Reduce fertilizer to 70% of base—soybean–rf –0.4% –$37 0.142 0.1% 0.0% $0 — 0.0% Reduce fertilizer to 70% of base—soybean–irri –0.3% –$39 0.118 0.1% 0.0% $0 — 0.0% Reduce fertilizer to 80% of base—wheat–rf –7.5% $29 0.217 0.2% –5.6% $6 0.129 0.2% Reduce fertilizer to 80% of base—wheat–irri –8.9% $103 0.432 0.4% –9.3% $229 0.175 0.3% Reduce fertilizer to 80% of base—maize–rf –10.5% –$249 –0.286 –0.3% –5.3% $43 0.167 0.2% Reduce fertilizer to 80% of base—maize–irri –10.5% –$223 –0.262 –0.3% –5.5% $55 0.054 0.1% Reduce fertilizer to 80% of base—soybean–rf –0.3% –$36 0.096 0.1% 0.0% $0 — 0.0% Reduce fertilizer to 80% of base—soybean–irri –0.2% –$38 0.080 0.1% 0.0% $0 — 0.0% Reduce fertilizer to 90% of base—wheat–rf –3.8% $28 0.110 0.1% –2.8% $6 0.065 0.1% Reduce fertilizer to 90% of base—wheat–irri –4.4% $101 0.220 0.2% –4.7% $247 0.083 0.1% Reduce fertilizer to 90% of base—maize–rf –5.2% –$276 –0.127 –0.1% –2.7% $45 0.081 0.1% Reduce fertilizer to 90% of base—maize–irri –5.2% –$240 –0.121 –0.1% –2.8% $59 0.026 0.0% Reduce fertilizer to 90% of base—soybean–rf –0.1% –$36 0.049 0.1% 0.0% $0 — 0.0% Reduce fertilizer to 90% of base—soybean–irri –0.1% –$38 0.040 0.0% 0.0% $0 — 0.0% Convert coventional tillage to no-till—wheat–rf 1.4% –$65 0.283 0.3% 2.7% –$29 0.150 0.2% Convert coventional tillage to no-till—wheat–irri 2.0% –$69 1.046 1.1% 5.5% –$61 0.954 1.4% Convert coventional tillage to no-till—maize–rf 1.4% –$86 1.143 1.2% 2.7% –$23 1.294 1.9% Convert coventional tillage to no-till—maize–irri 1.3% –$84 0.654 0.7% 2.0% –$23 0.329 0.5% Convert coventional tillage to no-till—soybean–rf 0.0% –$168 0.152 0.2% 1.3% –$70 0.131 0.2% Convert coventional tillage to no-till—soybean–irri 0.0% –$41 0.136 0.1% 1.3% –$23 0.010 0.0% EU-15 = European Union; NA = Data unavailable. 
SECTION V — AGRICULTURE • RESULTS 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES V-37

Table 1-12: Croplands: Percentage Reductions from Baselines at Different $/tCO2eq Prices 

2010 2020 

Country/Region $0 $15 $30 $45 $60 $0 $15 $30 $45 $60 

Africa 11.1% 12.8% 13.9% 14.5% 14.5% 10.6% 13.5% 13.6% 14.0% 14.2% 

Annex I 20.6% 23.2% 29.7% 30.2% 30.9% 19.6% 20.7% 24.2% 28.6% 29.2% 

Australia/New 

Zealand 

21.2% 21.2% 24.9% 34.7% 34.7% 21.9% 21.9% 26.1% 36.1% 36.1% 

Brazil 5.3% 5.3% 13.3% 13.3% 13.3% 4.5% 4.5% 12.3% 12.4% 12.4% 

China 6.4% 6.4% 6.7% 10.1% 12.7% 5.8% 6.3% 7.3% 10.5% 12.5% 

Eastern Europe 14.6% 18.8% 21.0% 21.5% 24.1% 13.5% 17.9% 20.8% 20.8% 20.8% 

EU-15 11.9% 12.7% 13.0% 13.7% 15.5% 10.8% 10.8% 11.4% 11.7% 13.8% 

India 6.2% 11.4% 11.4% 12.0% 12.4% 5.8% 11.5% 11.5% 11.5% 11.5% 

Japan 11.8% 11.8% 11.8% 11.8% 12.5% 11.0% 11.0% 11.0% 11.6% 11.6% 

Mexico 10.8% 14.3% 23.4% 23.4% 23.4% 10.5% 23.2% 23.2% 23.2% 23.2% 

Non-OECD Annex I 28.3% 28.3% 47.8% 47.9% 48.3% 28.0% 28.0% 31.7% 47.5% 47.9% 

OECD 18.0% 21.4% 23.8% 24.5% 25.0% 17.0% 18.7% 22.0% 22.9% 23.5% 

Russian Federation 28.3% 28.3% 47.8% 47.9% 48.3% 28.0% 28.0% 31.7% 47.5% 47.9% 

South & SE Asia 8.1% 8.3% 9.6% 13.5% 14.4% 8.3% 8.4% 11.0% 14.0% 14.3% 

United States 21.7% 25.9% 28.5% 28.5% 28.5% 20.3% 21.0% 26.5% 26.5% 26.5% 

World Total 15.4% 17.6% 22.0% 23.1% 24.0% 14.6% 16.2% 18.8% 22.0% 22.7% 

EU-15 = European Union; OECD = Organisation for Economic Co-operation and Development. 

Figure 1-7: Global MAC for Net Greenhouse Gas Emissions from Croplands, Holding Area Constant, 

2000–2020 

-50

0

50

100

150

200

0% 5% 10% 15% 20% 25% 30%

Percentage Reduction in Net GHG Emissions

$/tCO2eq

2000

2010

2020
SECTION V — AGRICULTURE • RESULTS 

V-38 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

Figure 1-8 shows the sensitivity of the global cropland MAC when only the three options that were 

most effective at mitigating net GHGs (nitrogen inhibitors, split fertilization, and no till) are applied. The 

excluded options (reducing baseline levels of nitrogen fertilizer by varying amounts) had little impact on 

net emissions at the global scale. As expected, the MAC with only the three most effective options—

where these options are each essentially applied to one-third of the cropland base—shows greater 

mitigation. 

Figure 1-8: Global MAC for Net Greenhouse Gas Emissions from Croplands, Holding Area Constant, 

Allocating Adoption of Mitigation Strategies to the Three Most Effective Options Only, 2000–

2020 

Figures 1-9, 1-10, 1-11, and 1-12 show the MACs for four major regions of the world—the United 

States, EU-15, FSU, and China. Each of those figures show simulated mitigation potential assuming equal 

adoption of the six mitigation options included for croplands. If mitigation strategies were limited to the 

three most effective options for emissions reductions, excluding the fertilizer reduction options that have 

little to no impact on net greenhouse gas in our DAYCENT model runs, total mitigation potential would 

increase. This is analogous to the change at the global level, observed in Figures 1-7 and 1-8. Percentage 

emissions reductions vary substantially, from less than 15 percent for China up to almost 50 percent in 

FSU. Among these four regions, the FSU has the largest emissions reduction potential, followed closely 

by the United States: both have emissions reductions above 50 MtCO2eq at less than $50/tCO2eq. EU-15 

and China have less than one-third of the emissions reductions of the FSU or United States, with potential 

reductions of 10 MtCO2eq to 15 MtCO2eq at $50/tCO2eq. 

-50

0

50

100

150

200

0% 5% 10% 15% 20% 25% 30%

Percentage Reduction in Net GHG Emissions

$/tCO2eq

2000

2010

2020
SECTION V — AGRICULTURE • RESULTS 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES V-39

Figure 1-9: MAC for Net Greenhouse Gas Emissions from Cropland Management in the United States, 

Holding Area Constant, 2000–2020 

Figure 1-10: MAC for Net Greenhouse Gas Emissions from Cropland Management in the EU-15, Holding 

Area Constant, 2000–2020 

-50

0

50

100

150

200

0% 5% 10% 15% 20% 25% 30% 35%

Percentage Reduction in Net GHG Emissions

$/tCO2eq

2000

2010

2020

-50

0

50

100

150

200

0% 5% 10% 15% 20%

Percentage Reduction in Net GHG Emissions

$/tCO2eq

2000

2010

2020
SECTION V — AGRICULTURE • RESULTS 

V-40 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

Figure 1-11: MAC for Net Greenhouse Gas Emissions from Cropland Management in the FSU, Holding 

Area Constant, 2000–2020 

Figure 1-12: MAC for Net Greenhouse Gas Emissions from Cropland Management in China, Holding Area 

Constant, 2000–2020 

-50

0

50

100

150

200

0% 10% 20% 30% 40% 50% 60%

Percentage Reduction in Net GHG Emissions

$/tCO2eq

2000

2010

2020

-50

0

50

100

150

200

0% 2% 4% 6% 8% 10% 12% 14% 16%

Percentage Reduction in Net GHG Emissions

$/tCO2eq

2000

2010

2020
SECTION V — AGRICULTURE • RESULTS 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES V-41

V.3.3 Baselines, Mitigation Costs, and MACs for Rice Cultivation 

Table 1-13 presents estimates of baseline net GHG emissions from rice cultivation by region by year 

used in this analysis. These are the values to which all estimated percentage reductions in emissions were 

applied. 

Table 1-13: Baseline Emissions from Rice Cultivation from DNDC Estimates (MtCO2eq) 

Country/Region 2000 2010 2020 

Africa — — — 

Annex I 45 28 27 

Australia/New Zealand — — — 

Brazil — — — 

China 385 301 302 

Eastern Europe — — — 

EU-15 — — — 

India 127 111 122 

Japan 45 28 27 

Mexico — — — 

Non-OECD Annex I — — — 

OECD 63 43 43 

Russian Federation — — — 

South & SE Asia 929 583 594 

United States — — — 

World Total 1,504 1,038 1,062 

EU-15 = European Union; OECD = Organisation for Economic Co-operation and Development. 

Table 1-14 presents information on the yield effects, emissions reductions, and costs associated with 

individual rice cultivation mitigation options for China and India. 

Table 1-15 provides estimates of the percentage reduction in net GHG emissions (relative to the rice 

cultivation baseline used in this analysis) that could potentially be achieved at prices between $0/tCO2eq 

and $60/tCO2eq for both 2010 and 2020 in major regions around the world. 

Figure 1-13 shows the MACs estimated for 2000, 2010, and 2020. This outward shift in the curve 

reflects changes in baseline emissions, commodity prices, labor rates, and other factors over time. Total 

global mitigation for rice CH4 is estimated to be around 3 percent at negative or zero cost and about 13 

percent at $45/tCO2eq in 2000. After that level, costs rise very rapidly. By 2010, global mitigation is 

estimated to have increased to about 11 percent at negative or zero cost and 24 percent at $45/tCO2eq. 

Between 2010 and 2020, there is little change in the MAC throughout most of its range. 

Figures 1-14 and 1-15 display the MACs for the key rice-producing regions of India and China, 

respectively. In both regions, the percentage emissions reduction is higher in 2010 than in 2000, but the 

curve shifts inward in 2020. This is largely due to substantial changes in the baseline emissions over time 

that are changing the reductions in net GHG relative to baseline conditions available. For instance, 

baseline emissions from China are projected to decline substantially over time, leaving fewer emissions to 

be abated in future years. DNDC simulations project baseline emissions from rice cultivation in China to 

fall by 21.5 percent between 2000 and 2020, from 384.9 MtCO2eq in 2000 to 302.1 MtCO2eq by 2020. 
SECTION V — AGRICULTURE • RESULTS 

V-42 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

Table 1-14: Rice Cultivation Mitigation Option Detail for Key Regions 

China India 

Option Labels 

Breakeven 

Cost 

($tCO2eq) 

Emission 

Reduction 

(absolute, 

MtCO2eq) 

Emission 

Reduction 

(1% from 

baseline) 

Change in 

Output 

Yield (% 

from 

baseline) 

Breakeven 

Cost 

($tCO2eq) 

Emission 

Reduction 

(absolute, 

MtCO2eq) 

Emission 

Reduction 

(1% from 

baseline) 

Change in 

Output 

Yield (% 

from 

baseline) 

Midseason drainage—

rice(rf) 

NA NA NA NA NA NA NA NA 

Midseason drainage—

rice(irri) 

3.2% –$11.4 3.5 1.2% 0.7% 4 8.9 8.0% 

Shallow flooding—

rice(rf) 

NA NA NA NA NA NA NA NA 

Shallow flooding—

rice(irri) 

5.5% –$1.9 28.6 9.5% 0.3% 7 14.9 13.4% 

Offseason straw—

rice(rf) 

NA NA NA NA 0.0% 81 0.3 0.3% 

Offseason straw—

rice(irri) 

2.1% –$3.6 2.2 0.7% 0.0% 9 5.7 5.2% 

Sulfate fertilizer—

rice(rf) 

NA NA NA NA 0.0% 89 0.3 0.3% 

Sulfate fertilizer—

rice(irri) 

1.8% –$2.9 13.1 4.4% –0.3% 19 2.0 1.8% 

Slow-release 

fertilizers—rice(rf) 

NA NA NA NA 0.0% 248 0.3 0.2% 

Slow-release 

fertilizer—rice(irri) 

5.4% $27.9 –2.3 –0.8% –0.3% –319 –0.3 –0.2% 

Switch to upland 

rice—rice(rf) 

NA NA NA NA 6.1% 21 –3.9 –3.5% 

Switch to upland 

rice—rice(irri) 

–15.0% $10.1 45.1 15.0% –32.9% 62 15.7 14.1% 

NA = Data unavailable. 
SECTION V — AGRICULTURE • RESULTS 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES V-43

Table 1-15: Rice Cultivation: Percentage Reductions from Baseline at Different $/tCO2eq Prices 

2010 2020 

Country/Region $0 $15 $30 $45 $60 $0 $15 $30 $45 $60 

Africa NA NA NA NA NA NA NA NA NA NA 

Annex I 1.6% 24.1% 24.1% 24.1% 24.1% 1.6% 24.4% 24.4% 24.4% 24.4% 

Australia/New 

Zealand 

NA NA NA NA NA NA NA NA NA NA 

Brazil NA NA NA NA NA NA NA NA NA NA 

China 15.8% 30.8% 30.0% 30.0% 30.0% 13.1% 26.3% 27.0% 27.0% 27.0% 

Eastern Europe NA NA NA NA NA NA NA NA NA NA 

EU-15 NA NA NA NA NA NA NA NA NA NA 

India –0.2% 26.4% 24.7% 24.7% 24.7% –0.3% 25.9% 25.9% 25.9% 25.9% 

Japan 1.6% 24.1% 24.1% 24.1% 24.1% 1.6% 24.4% 24.4% 24.4% 24.4% 

Mexico NA NA NA NA NA NA NA NA NA NA 

Non-OECD Annex I NA NA NA NA NA NA NA NA NA NA 

OECD 4.0% 19.5% 24.8% 24.8% 24.8% 4.4% 25.0% 25.0% 25.0% 25.0% 

Russian Federation NA NA NA NA NA NA NA NA NA NA 

South & SE Asia 10.4% 16.6% 16.8% 20.7% 22.3% 12.1% 19.1% 19.1% 22.7% 22.7% 

United States NA NA NA NA NA NA NA NA NA NA 

World Total 10.5% 21.9% 21.8% 24.0% 24.9% 10.7% 22.1% 22.4% 24.4% 24.4% 

EU-15 = European Union; OECD = Organisation for Economic Co-operation and Development; NA = Data unavailable. 

Figure 1-13: Global MAC for Net Greenhouse Gas Emissions from Rice Cultivation, Holding Area 

Constant, 2000–2020 

-50

0

50

100

150

200

0% 5% 10% 15% 20% 25% 30%

Percentage Reduction in Net GHG Emissions

$/tCO2eq

2000

2010

2020
SECTION V — AGRICULTURE • RESULTS 

V-44 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

Figure 1-14: MAC for Net Greenhouse Gas Emissions from Rice Cultivation in India, Holding Area 

Constant, 2000–2020 

Figure 1-15: MAC for Net Greenhouse Gas Emissions from Rice Cultivation in China, Holding Area 

Constant, 2000–2020 

-50

0

50

100

150

200

0% 10% 20% 30% 40% 50%

Percentage Reduction in Net GHG Emissions

$/tCO2eq

2000

2010

2020

-50

0

50

100

150

200

0% 5% 10% 15% 20% 25% 30% 35%

Percentage Reduction in Net GHG Emissions

$/tCO2eq

2000

2010

2020
SECTION V — AGRICULTURE • RESULTS 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES V-45

V.3.4 Baselines, Mitigation Costs, and MACs for Livestock 

Management 

Table 1-16 presents estimates of baseline net GHG emissions from livestock enteric fermentation and 

manure management by region and by year. These are the values to which all estimated percentage 

reductions in emissions were applied. 

Table 1-17 presents information on the yield effects, emissions reductions, and costs associated with 

individual livestock management mitigation options for the USA, EU-15, Brazil, China, and India. 

Table 1-16: Baseline Emissions from Livestock Management from USEPA (2006) (MtCO2eq) 

Country/Region 2000 2010 2020 

Africa 271 332 395 

Annex I 704 718 748 

Australia/New Zealand 91 93 94 

Brazil 222 263 297 

China 313 392 470 

Eastern Europe 48 54 58 

EU-15 222 203 202 

India 224 260 286 

Japan 20 21 22 

Mexico 43 50 57 

Non-OECD Annex I 111 131 150 

OECD 642 644 663 

Russian Federation 66 78 91 

South & SE Asia 187 232 276 

United States 171 173 171 

World Total 2,220 2,548 2,867 

EU-15 = European Union; OECD = Organisation for Economic Co-operation and Development. 
SECTION V — AGRICULTURE • RESULTS 

V-46 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES Table 1-17: Livestock Mitigation Option Detail for Key Regions United States EU-15 Brazil Livestock Change in Output Yield (% from baseline) Breakeven Cost ($/tCO2eq) Emissions Reduction (Absolute, MtCO2eq) Emissions Reduction (% from baseline) Change in Output Yield (% from baseline) Breakeven Cost ($/tCO2eq) Emissions Reduction (Absolute, MtCO2eq) Emissions Reduction (% from baseline) Change in Output Yield (% from baseline) Breakeven Cost ($/tCO2eq) Emissions Reduction (Absolute, MtCO2eq) Emissions Reduction (% from baseline) Improved feed conversion—beef 0.2% –$1,126 –0.2 –0.1% 7.7% $238 –0.1 –0.1% 2.5% $102 1.3 0.5% Improved feed conversion—dairy 0.0% –$655 –0.7 –0.4% 0.0% $5,335 0.1 0.0% 87.9% $187 –2.6 –1.0% Antibiotics—beef 5.0% –$265 0.5 0.3% 5.0% –$121 0.7 0.4% 5.0% –$31 0.9 0.3% bST—dairy 11.2% $888 –0.1 –0.1% 12.5% –$5,597 0.0 0.0% 12.5% –$1,097 –0.6 –0.2% Propionate precursors—beef 5.0% $89 1.6 1.0% 5.0% $81 1.2 0.6% 5.0% $50 4.0 1.5% Propionate precursors—dairy 5.0% –$68 1.4 0.8% 5.0% $183 2.1 1.0% 5.0% $322 1.6 0.6% Antimethanogen—beef 5.0% –$60 1.6 1.0% 5.0% –$53 1.2 0.6% 5.0% $0 4.0 1.5% Antimethanogen—sheep & goats 5.0% $184 0.1 0.1% 5.0% $327 1.5 0.8% 5.0% $131 0.4 0.2% Antimethanogen—dairy 5.0% –$430 0.5 0.3% 5.0% –$288 0.8 0.4% 5.0% $20 0.7 0.3% Intensive grazing—beef 0.0% –$70 2.2 1.3% 0.0% $24 1.7 0.8% 0.0% –$14 5.4 2.1% Intensive grazing—dairy –11.2% $371 0.8 0.5% –11.2% $725 1.3 0.6% –11.2% $78 1.0 0.4% Complete-mix digester with engine—hogs 0.0% $25 2.5 1.4% 0.0% $7 3.9 1.9% NA NA NA NA Complete-mix digester with engine—dairy 0.0% $12 1.7 1.0% 0.0% –$21 1.4 0.7% NA NA NA NA Plug-flow digester with engine— dairy 0.0% $8 1.7 1.0% 0.0% –$40 1.4 0.7% NA NA NA NA Fixed-film digester with engine— hogs 0.0% $31 2.5 1.4% 0.0% $15 3.9 1.9% NA NA NA NA Fixed-film digester with engine— dairy 0.0% $16 1.7 1.0% 0.0% –$2 1.4 0.7% NA NA NA NA Complete-mix digester without engine—hogs 0.0% $39 2.5 1.4% 0.0% $46 3.9 1.9% NA NA NA NA Complete-mix digester without engine—dairy 0.0% $23 1.7 1.0% 0.0% $115 1.4 0.7% NA NA NA NA Plug-flow digester without engine— dairy 0.0% $20 1.7 1.0% 0.0% $103 1.4 0.7% NA NA NA NA Fixed-film digester without engine—hogs 0.0% $43 2.5 1.4% 0.0% $51 3.9 1.9% NA NA NA NA Fixed-film digester without engine—dairy 0.0% $25 1.7 1.0% 0.0% $127 1.4 0.7% NA NA NA NA Covered lagoon with engine—hogs 0.0% –$7 2.5 1.4% 0.0% –$30 3.9 1.9% 0.0% –$101 0.2 0.1% Covered lagoon with engine—dairy 0.0% $5 1.7 1.0% 0.0% –$59 1.4 0.7% 0.0% –$447 0.2 0.1% (continued) 
SECTION V — AGRICULTURE • RESULTS 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES V-47 Table 1-17: Livestock Mitigation Option Detail for Key Regions (continued) United States EU-15 Brazil Livestock Change in Output Yield (% from baseline) Breakeven Cost ($/tCO2eq) Emissions Reduction (Absolute, MtCO2eq) Emissions Reduction (% from baseline) Change in Output Yield (% from baseline) Breakeven Cost ($/tCO2eq) Emissions Reduction (Absolute, MtCO2eq) Emissions Reduction (% from baseline) Change in Output Yield (% from baseline) Breakeven Cost ($/tCO2eq) Emissions Reduction (Absolute, MtCO2eq) Emissions Reduction (% from baseline) Covered lagoon without engine— hogs 0.0% $18 2.5 1.4% 0.0% $22 3.9 1.9% 0.0% $23 0.2 0.1% Covered lagoon without engine— dairy 0.0% $18 1.7 1.0% 0.0% $90 1.4 0.7% 0.0% $402 0.2 0.1% Domes cook fuel, light—hogs NA NA NA NA NA NA NA NA 0.0% –$135 0.1 0.0% Domes cook fuel, light—dairy NA NA NA NA NA NA NA NA 0.0% –$2,145 0.1 0.1% Polyethylene bags cook fuel, light— hogs NA NA NA NA NA NA NA NA 0.0% –$92 0.1 0.0% Polyethylene bags cook fuel, light— dairy NA NA NA NA NA NA NA NA 0.0% –$553 0.1 0.1% Covered lagoon cook fuel, light, shaft power—hogs NA NA NA NA NA NA NA NA 0.0% –$77 0.1 0.0% Covered lagoon cook fuel, light, shaft power—dairy NA NA NA NA NA NA NA NA 0.0% –$345 0.1 0.1% Flexible bag (pilot)—hogs NA NA NA NA NA NA NA NA 0.0% –$70 0.1 0.0% Flexible bag (pilot)—dairy NA NA NA NA NA NA NA NA 0.0% –$251 0.1 0.1% EU-15 = European Union; NA = Data unavailable. (continued) 
SECTION V — AGRICULTURE • RESULTS 

V-48 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES Table 1-17: Livestock Mitigation Option Detail for Key Regions (continued) China India Livestock Change in Output Yield (% from baseline) Breakeven Cost ($/tCO2eq) Emissions Reduction (Absolute, MtCO2eq) Emissions Reduction (% from baseline) Change in Output Yield (% from baseline) Breakeven Cost ($/tCO2eq) Emissions Reduction (Absolute, MtCO2eq) Emissions Reduction (% from baseline) Improved feed conversion—beef 46.6% –$143 2.9 0.7% 69.0% –$382 0.7 0.3% Improved feed conversion—dairy 6.2% $567 0.6 0.1% 16.9% $62 1.3 0.5% Antibiotics—beef 5.0% –$41 0.6 0.1% 5.0% –$8 0.2 0.1% bST—dairy 12.5% –$5,807 –0.2 –0.1% 12.5% –$6,438 –0.4 –0.2% Propionate precursors—beef 5.0% $82 4.0 1.0% 5.0% $126 2.2 0.8% Propionate precursors—dairy 5.0% $1,668 0.6 0.2% 5.0% $1,258 2.0 0.8% Antimethanogen—beef 5.0% $5 4.0 1.0% 5.0% $15 2.2 0.8% Antimethanogen—sheep & goats 5.0% $229 5.0 1.3% 5.0% $322 1.7 0.7% Antimethanogen—dairy 5.0% $205 0.2 0.1% 5.0% $29 0.8 0.3% Intensive grazing—beef NA NA NA NA NA NA NA NA Intensive grazing—dairy NA NA NA NA NA NA NA NA Complete-mix digester with engine—hogs 0.0% $13 1.3 0.3% NA NA NA NA Complete-mix digester with engine—dairy NA NA NA NA NA NA NA NA Plug-flow digester with engine—dairy NA NA NA NA NA NA NA NA Fixed-film digester with engine—hogs 0.0% $27 1.3 0.3% NA NA NA NA Fixed-film digester with engine—dairy NA NA NA NA NA NA NA NA Complete-mix digester without engine—hogs 0.0% $94 1.3 0.3% NA NA NA NA Complete-mix digester without engine—dairy 0.0% $956 0.1 0.0% NA NA NA NA Plug-flow digester without engine—dairy 0.0% $851 0.1 0.0% NA NA NA NA Fixed-film digester without engine—hogs 0.0% $103 1.3 0.3% NA NA NA NA Fixed-film digester without engine—dairy 0.0% $1,062 0.1 0.0% NA NA NA NA Covered lagoon with engine—hogs 0.0% –$55 1.3 0.3% NA NA NA NA Covered lagoon with engine—dairy NA NA NA NA NA NA NA NA Covered lagoon without engine—hogs 0.0% $50 1.3 0.3% 0.0% $11 0.3 0.1% Covered lagoon without engine—dairy 0.0% $745 0.1 0.0% 0.0% $448 0.7 0.3% Domes cook fuel, light—hogs 0.0% –$101 0.8 0.2% 0.0% –$105 0.2 0.1% Domes cook fuel, light—dairy 0.0% –$1,968 0.1 0.0% 0.0% –$4,508 0.4 0.2% Polyethylene bags cook fuel, light—hogs 0.0% –$68 0.8 0.2% 0.0% –$74 0.2 0.1% Polyethylene bags cook fuel, light—dairy 0.0% –$469 0.1 0.0% 0.0% –$1,165 0.4 0.2% Covered lagoon cook fuel, light, shaft power—hogs 0.0% –$36 0.8 0.2% 0.0% –$65 0.2 0.1% Covered lagoon cook fuel, light, shaft power—dairy 0.0% –$85 0.1 0.0% 0.0% –$936 0.4 0.2% Flexible bag (pilot)—hogs 0.0% –$21 0.8 0.2% 0.0% –$61 0.2 0.1% Flexible bag (pilot)—dairy 0.0% $89 0.1 0.0% 0.0% –$832 0.4 0.2% EU-15 = European Union; NA = Data unavailable. 
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GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES V-49

Table 1-18 provides estimates of the percentage reduction in net GHG emissions (relative to the 

livestock emissions baseline used in this analysis) that could potentially be achieved at prices between 

$0/tCO2eq and $60/tCO2eq for both 2010 and 2020 in major regions around the world. 

Table 1-18: Livestock Management: Percentage Reductions from Baselines at Different $/tCO2eq Prices 

2010 2020 

Country/Region $0 $15 $30 $45 $60 $0 $15 $30 $45 $60 

Africa 0.7% 2.1% 2.6% 3.5% 3.6% 0.5% 2.1% 2.6% 3.5% 3.6% 

Annex I 5.0% 6.9% 10.1% 11.3% 12.5% 4.9% 7.4% 10.3% 11.9% 12.7% 

Australia/New 

Zealand 

4.1% 4.3% 6.8% 7.5% 8.4% 4.2% 4.6% 7.2% 7.7% 8.7% 

Brazil 2.9% 4.5% 4.9% 4.9% 6.5% 2.9% 4.5% 4.9% 4.9% 6.5% 

China 2.0% 3.4% 3.7% 3.7% 4.1% 2.0% 3.4% 3.7% 3.7% 4.0% 

Eastern Europe 2.7% 2.7% 2.7% 2.7% 2.7% 2.7% 2.7% 2.7% 2.7% 3.5% 

EU-15 6.3% 10.1% 13.0% 13.0% 16.9% 6.4% 10.3% 12.2% 15.2% 17.1% 

India 1.2% 2.1% 2.5% 2.5% 2.5% 1.2% 2.5% 2.5% 2.5% 2.5% 

Japan 4.0% 4.0% 4.4% 4.4% 4.4% 4.1% 4.1% 4.1% 4.4% 4.4% 

Mexico 3.3% 3.3% 3.3% 3.4% 3.4% 3.3% 3.3% 3.3% 3.4% 3.4% 

Non-OECD Annex I 2.5% 2.5% 2.5% 2.5% 2.5% 2.4% 2.4% 2.4% 2.4% 3.0% 

OECD 5.4% 7.4% 11.1% 12.5% 13.8% 5.3% 8.1% 11.4% 13.3% 14.0% 

Russian Federation 2.4% 2.4% 2.4% 2.4% 2.4% 2.4% 2.4% 2.4% 2.4% 2.9% 

South & SE Asia 3.9% 5.3% 6.1% 6.2% 6.6% 3.5% 4.6% 6.0% 6.0% 6.5% 

United States 6.4% 9.4% 17.2% 21.4% 21.4% 6.3% 11.8% 19.8% 23.0% 23.0% 

World Total 3.0% 4.4% 5.6% 6.1% 6.8% 2.9% 4.4% 5.5% 6.1% 6.7% 

EU-15 = European Union; OECD = Organisation for Economic Co-operation and Development. 

Total global mitigation for livestock management in 2020, holding the number of animals constant, is 

estimated to be 3 percent at negative or zero cost, reaching about 7 percent at $60/tCO2eq (Figure 1-16). 

Figure 1-17 shows the global MAC, holding production constant. The percentage of baseline emissions 

mitigated at $60/tCO2eq increases from just under 7 percent with a constant number of animals to over 10 

percent with constant production. If other greenhouse gas benefits were included (e.g., soil carbon 

increases, cropland N2O reductions for less feed), the estimates of greenhouse gas mitigation would be 

higher, but no model was identified to allow estimation of multigas impacts for livestock analogous to 

the DNDC and DAYCENT models used for cropland management and rice cultivation. 

Figures 1-18, 1-19, 1-20, and 1-21 show the MACs for mitigation of greenhouse gas emissions from 

livestock management for the United States, China, India, and Brazil, respectively, holding the number of 

animals constant. Among these four regions, the United States has the greatest potential for relatively 

low-cost reductions in emissions in this sector, followed by China, Brazil, and India. 

Because some options for mitigating emissions from enteric fermentation rely on improvements in 

yield resulting in fewer animals to achieve emissions reductions, assumptions about changes in livestock 

populations and production are important to examine for this sector. Thus, MACs are presented for the 

United States, China, India, and Brazil, assuming that production remains constant (Figures 1-22, 1-23, 

1-24, and 1-25) to show the impact of this assumption. The differences between the two sets of graphs 
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V-50 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

Figure 1-16: Global MAC for Greenhouse Gas Emissions from Livestock Management, Holding Number 

of Animals Constant, 2000–2020 

Figure 1-17: Global MAC for Greenhouse Gas Emissions from Livestock Management, Holding 

Production Constant, 2000–2020 

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GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES V-51

Figure 1-18: MAC for Greenhouse Gas Emissions from Livestock Management in the United States, 

Holding Number of Animals Constant, 2000–2020 

Figure 1-19: MAC for Greenhouse Gas Emissions from Livestock Management in China, Holding Number 

of Animals Constant, 2000–2020 

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V-52 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

Figure 1-20: MAC for Greenhouse Gas Emissions from Livestock Management in India, Holding Number 

of Animals Constant, 2000–2020 

Figure 1-21: MAC for Greenhouse Gas Emissions from Livestock Management in Brazil, Holding Number 

of Animals Constant, 2000–2020 

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GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES V-53

Figure 1-22: MAC for Greenhouse Gas Emissions from Livestock Management in the United States, 

Holding Production Constant, 2000–2020 

Figure 1-23: MAC for Greenhouse Gas Emissions from Livestock Management in China, Holding 

Production Constant, 2000–2020 

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90

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130

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V-54 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

Figure 1-24: MAC for Greenhouse Gas Emissions from Livestock Management in India, Holding 

Production Constant, 2000–2020 

Figure 1-25: MAC for Greenhouse Gas Emissions from Livestock Management in Brazil, Holding 

Production Constant, 2000–2020 

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GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES V-55

reveal the importance of this assumption, because total mitigation is substantially larger at any given 

price when production is assumed to remain constant. For those options that increase yields, constant 

production can be maintained while reducing the number of livestock by an amount corresponding to the 

increase in productivity. These reductions in the number of livestock can have a sizable impact on 

emissions. With an assumption that the number of animals remains constant, emissions tend to fall less 

because the reductions in emissions only come from the change in emissions per animal with no change 

in emissions due to a change in population. Some mitigation options even increase net greenhouse gas 

emissions per animal but increase productivity by an even greater proportion, leading to lower emissions 

per unit of output. If a constant number of animals is assumed, however, then these options will lead to 

an increase in emissions. 

V.3.5 Baselines, Mitigation Costs, and MACs for Total Agriculture 

Table 1-19 presents estimates of baseline net GHG emissions from agriculture, aggregated across 

croplands management, rice cultivation, and livestock management by region by year used in this 

analysis. These are the values to which all estimated percentage reductions in emissions were applied. 

Table 1-19: Baseline Emissions from All Agriculture Used in This Report (MtCO2eq) 

Country/Region 2000 2010 2020 

Africa 301 364 431 

Annex I 1,258 1,230 1,297 

Australia/New Zealand 104 109 111 

Brazil 249 292 327 

China 789 791 876 

Eastern Europe 86 93 99 

EU-15 313 296 303 

India 417 441 480 

Japan 65 49 50 

Mexico 57 67 85 

Non-OECD Annex I 282 254 274 

OECD 1,018 1,026 1,080 

Russian Federation 237 201 215 

South & SE Asia 1,141 842 898 

United States 338 351 370 

World Total 4,563 4,417 4,822 

EU-15 = European Union; OECD = Organisation for Economic Co-operation and Development. 

Note: These emissions reflect the baseline emissions used in calculating agricultural mitigation. 

Table 1-20 provides estimates of the percentage reduction in net GHG emissions (relative to the 

aggregated agricultural emissions baseline used in this analysis) that could potentially be achieved at 

prices between $0/tCO2eq and $60/tCO2eq for both 2010 and 2020 in major regions around the world. 

Figures 1-26 and 1-27 present MACs for global agriculture, aggregated across croplands 

management, rice cultivation, and livestock management, for assumptions of constant area and number 

of animals and constant production, respectively. 
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V-56 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

Table 1-20: Total Agriculture: Percentage Reductions from Baseline at Different $/tCO2eq Prices 

2010 2020 

Country/Region $0 $15 $30 $45 $60 $0 $15 $30 $45 $60 

Africa 1.6% 3.1% 3.6% 4.5% 4.5% 1.4% 3.0% 3.5% 4.4% 4.4% 

Annex I 11.1% 13.7% 18.1% 19.1% 20.0% 10.8% 13.1% 16.2% 18.9% 19.6% 

Australia/New 

Zealand 

6.7% 6.9% 9.5% 11.6% 12.4% 6.9% 7.3% 10.2% 12.1% 12.9% 

Brazil 3.2% 4.5% 5.8% 5.8% 7.2% 3.1% 4.5% 5.6% 5.6% 7.0% 

China 7.8% 14.2% 14.1% 14.5% 15.0% 6.3% 11.6% 12.1% 12.5% 12.9% 

Eastern Europe 7.7% 9.5% 10.4% 10.7% 11.7% 7.2% 9.0% 10.3% 10.3% 10.7% 

EU-15 8.1% 10.9% 13.0% 13.3% 16.4% 7.9% 10.5% 12.0% 14.0% 16.0% 

India 1.6% 9.7% 9.5% 9.6% 9.7% 1.5% 9.3% 9.3% 9.3% 9.3% 

Japan 2.7% 15.5% 15.6% 15.6% 15.6% 2.8% 15.5% 15.5% 15.7% 15.7% 

Mexico 5.2% 6.0% 8.3% 8.3% 8.3% 5.0% 8.0% 8.0% 8.0% 8.0% 

Non-OECD Annex I 15.0% 15.0% 24.4% 24.5% 24.7% 14.0% 14.0% 15.7% 22.9% 23.3% 

OECD 9.5% 12.5% 15.8% 16.9% 17.9% 9.3% 12.4% 15.6% 17.0% 17.7% 

Russian Federation 18.2% 18.2% 30.1% 30.2% 30.4% 17.2% 17.2% 19.3% 28.4% 28.9% 

South & SE Asia 8.5% 13.3% 13.7% 16.4% 17.7% 9.2% 14.1% 14.6% 17.0% 17.2% 

United States 14.2% 17.8% 22.9% 25.0% 25.0% 13.8% 16.8% 23.4% 24.9% 24.9% 

World Total 7.1% 11.0% 12.5% 13.5% 14.3% 6.7% 10.4% 11.6% 13.0% 13.4% 

EU-15 = European Union; OECD = Organisation for Economic Co-operation and Development. 

Figure 1-26: Global MAC for Net Greenhouse Gas Emissions from Agriculture, Holding Area/Animals 

Constant, 2000–2020 

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GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES V-57

Figure 1-27: Global MAC for Net Greenhouse Gas Emissions from Agriculture, Holding Production 

Constant, 2000–2020 

V.3.6 Agricultural Commodity Market Impacts of Adopting Mitigation 

Options: Use of the IMPACT Model 

Many of the mitigation options considered for the agricultural sector have substantial impacts on 

agricultural productivity and/or the cost of production. As a result, any significant adoption of these 

options is expected to shift the market supply curves and move agricultural commodity markets to new 

equilibrium points. Increases in productivity will have positive supply shifts and will tend to increase 

market equilibrium quantity and reduce market prices, whereas increases in production costs will have 

the opposite effect, reducing market quantity and putting upward pressure on market prices. Thus, 

market equilibrium price and quantity could be either higher or lower than current and projected 

baseline levels, depending on the net effects of the mitigation options. Not only do these market-level 

impacts affect the cost of greenhouse gas mitigation, they also affect total mitigation, because emissions 

are generally tied to the quantity of output produced. For instance, there may be an option that reduces 

net greenhouse gas emissions per hectare of cropland but through broader market effects then leads to an 

increase in equilibrium cropland area. With a large enough increase in area, total emissions from 

adopting the option may actually increase because additional emissions from the larger area more than 

offset the reduction in emissions per hectare. 

To examine the magnitude of these market-level effects in agricultural markets, IFPRI’s IMPACT 

model is used. IMPACT models world supply and demand for agricultural products for 36 world 

regions, as well as trade between regions. The model is capable of incorporating shifts in supply and/or 

demand in one or more commodities in one or more regions and then solving for a new global 

equilibrium in all commodities. 

For cropland and rice cultivation options, estimated percentage changes in yield (kg/hectare) and 

percentage changes in production costs per unit of output ($/metric ton) for each mitigation option were 

provided as inputs to the IMPACT model. Similarly, percentage changes in milk or meat production per 

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V-58 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

animal (kg/head) and production costs per unit of output ($/metric ton) estimated for each enteric 

fermentation option were provided as inputs to IMPACT. Manure management greenhouse gas 

mitigation options were assumed to have no impact on livestock productivity and were not run through 

the IMPACT model. 

Applying the percentage changes in productivity and costs implied by the mitigation options to the 

baseline levels of these variables in the IMPACT model, the model moves to a new equilibrium. The 

values for key variables in the baseline and mitigation scenario are then compared to determine the 

incremental impacts of adopting the mitigation option. Mitigation options are run through the model 

independently from other options, but each option is applied simultaneously to all regions where that 

option was believed to be feasible. 

Two illustrative examples are presented to show the market adjustments being captured in the 

IMPACT model and the influence of those adjustments on the abatement curves. The first examines the 

effects of global adoption of the antimethanogen vaccine option on beef, dairy, and sheep and goat meat 

markets relative to baseline values. As shown in Figure 1-28, world prices are reduced for all three of the 

primary livestock categories that may adopt this mitigation option, with reductions ranging from about 4 

percent to 9 percent. Figure 1-29 presents the effects on global production, where production increases by 

2 percent to 4 percent for each product. In Figure 1-30, the impacts on global animal numbers are shown. 

The IMPACT model estimates reductions in the number of animals of approximately 0.5 percent to 2 

percent for each livestock category included. These changes in prices, production, and animal numbers 

are attributable to the increase in productivity associated with this option. Although there are costs of 

purchasing and administering the vaccine, the increase in productivity more than offsets these costs in 

most regions, leading to more production from fewer animals. The resulting positive supply shift 

decreases equilibrium market price. 

Figure 1-28: Effect of Global Adoption of the Antimethanogen Vaccine Mitigation Option on World Prices 

Using the IMPACT Model 

0

500

1,000

1,500

2,000

2,500

3,000

3,500

2000 2010 2020

Year

$/ton

Beef Baseline Beef Vaccine Dairy Baseline

Dairy Vaccine Sheep and Goats Baseline Sheep and Goats Vaccine
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GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES V-59

Figure 1-29: Effect of Global Adoption of the Antimethanogen Vaccine Mitigation Option on Global 

Production Using the IMPACT Model 

Figure 1-30: Effect of Global Adoption of the Antimethanogen Vaccine Mitigation Option on Global 

Number of Animals Using the IMPACT Model 

0

100,000

200,000

300,000

400,000

500,000

600,000

700,000

800,000

2000 2010 2020

Year

1,000 tons .

Beef Baseline Beef Vaccine

Dairy Baseline Dairy Vaccine

Sheep and Goat Meat Baseline Sheep and Goat Meat Vaccine

0

200,000

400,000

600,000

800,000

1,000,000

1,200,000

2000 2010 2020

Year

1,000 head .

Beef Baseline Beef Vaccine Dairy Baseline

Dairy Vaccine Sheep and Goats Baseline Sheep and Goats Vaccine
SECTION V — AGRICULTURE • RESULTS 

V-60 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

The second example simulates the effects of global adoption of the shallow flooding mitigation 

option on rice markets relative to baseline values. The shallow flooding option is expected to result in 

both reduced emissions and higher productivity. As shown in Figure 1-31, the global price of rice is 

reduced, with reductions ranging from about 3 percent to 10 percent. Figure 1-32 presents the effects on 

global rice production, where production increases by 1 percent to 2.5 percent. In Figure 1-33, the impact 

on global rice area is shown, with the IMPACT model estimating acreage reductions between 0.3 to 1 

percent. Similar to the antimethanogen vaccine option examined above, this option results in an increase 

in productivity, which results in more production from less area. The positive supply shift leads to a 

decrease in equilibrium market price. 

These market-level changes in area, production, and price are then incorporated into the MAC to 

examine the sensitivity of the MACs to inclusion of market effects. These effects are potentially very 

important because many options will have an effect on equilibrium prices and quantities if widely 

adopted, which will affect the cost of mitigation, as well as total mitigation achieved. However, the 

engineering approach used in this report is unable to capture feedbacks from changing market 

conditions. For comparison purposes, the MAC curves without market adjustments are recalculated with 

full adoption of a single option being analyzed to be consistent with the MACs calculated using IMPACT 

model results. 

Figure 1-34 compares net GHG abatement under global adoption of the antimethanogen vaccine 

calculated three different ways: 1) with the number of animals held constant, 2) with production of the 

relevant commodities held constant, and 3) allowing both number of animals and production to vary, as 

well as reflecting other market adjustments simulated using the IMPACT model. Mitigation with 

production held constant is much greater than with the number of animals held constant because this is 

an option that increases productivity. Thus, the same production level can be achieved with fewer 

animals, which provides additional emissions reductions on top of the reduction in emissions per animal 

associated with the option. Incorporating market adjustments results in a price decrease, which leads to 

reduced incentives for investment and production in the livestock sector than if price were constant. 

Thus, the increase in production is smaller than for the constant number of animals case. Because there is 

an increase in production under the market adjustments scenario, the reduction in number of animals is 

smaller than for the constant production case. In addition, there are shifts in production regions and trade 

patterns, though the changes are relatively small for this particular option. 

Similarly, Figure 1-35 compares net GHG abatement under global adoption of the shallow flooding 

mitigation option: 1) with rice area held constant, 2) with rice production held constant, and 3) allowing 

both area and production to vary, as well as reflecting other market adjustments simulated by the 

IMPACT model. Mitigation is similar with area held constant and production held constant for this 

option because the yield changes are relatively small, causing less differentiation between calculation 

method. The global curve with market adjustments is similar to the area constant and production 

constant curves other than at very low and very high prices. However, there are differences in the regions 

estimated to provide mitigation at different price levels depending on the abatement cost calculation 

method. Because there are larger differences in estimated yield changes between regions, there are more 

substantial shifts in production regions and trade patterns than for the antimethanogen vaccine option 

considered above. 
SECTION V — AGRICULTURE • RESULTS 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES V-61

Figure 1-31: Effect of Global Adoption of the Shallow Flooding Mitigation Option on World Prices Using 

the IMPACT Model 

Figure 1-32: Effect of Global Adoption of the Shallow Flooding Mitigation Option on Global Production 

Using the IMPACT Model 

0

50

100

150

200

250

2000 2010 2020

Year

$/ton

Rice Baseline Rice SF

0

100,000

200,000

300,000

400,000

500,000

600,000

2000 2010 2020

Year

1,000 tons

Rice Baseline Rice SF
SECTION V — AGRICULTURE • RESULTS 

V-62 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

Figure 1-33: Effect of Global Adoption of the Shallow Flooding Mitigation Option on Global Rice Area 

Using the IMPACT Model 

Figure 1-34: Net GHG Abatement under Global Adoption of the Antimethanogen Vaccine Option with 

Number of Cattle Constant, Production Constant, and Market Adjustments Using the 

IMPACT Model, 2010 

145,000

146,000

147,000

148,000

149,000

150,000

151,000

152,000

153,000

154,000

2000 2010 2020

Year

1,000 ha .

Rice Baseline Rice SF

-50

-25

0

25

50

75

100

125

150

175

200

0% 2% 4% 6% 8% 10% 12%

Percentage Reduction in Net GHG Relative to Baseline

$/tCO2eq

# Animals Constant

Production Constant

# Animals+Production+Other Market Adjustments
SECTION V — AGRICULTURE • RESULTS 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES V-63

Figure 1-35: Comparison of Net GHG Abatement from Rice Cultivation under Global Adoption of the 

Shallow Flooding Mitigation Option with Area Constant, Production Constant, and Market 

Adjustments Using the IMPACT Model, 2010 

(50)

(25)

0

25

50

75

100

0% 10% 20% 30% 40% 50% 60%

Percentage Reduction in Net GHG Relative to Baseline

$/tCO2eq

Area Constant

Production Constant

Area+Production+Other Market Adjustments
SECTION V — AGRICULTURE • RESULTS 

V-64 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 
SECTION V — AGRICULTURE • CONCLUSIONS 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES V-65

V.4 Conclusions 

The agricultural sector generates the largest share of global non-CO2 greenhouse gas emissions and a 

significant share of total global greenhouse gas emissions. Emissions in this sector are projected to 

increase significantly over the foreseeable future, especially in developing countries. Mitigation options to 

abate agricultural non-CO2 emissions have been identified in the literature for most significant sources. 

This report uses a number of data sources, analytic tools, and modeling approaches to compile and 

estimate baseline emissions of the most significant world agricultural non-CO2 sources and to estimate 

the costs of the technical mitigation potential for key regions and world totals. This report makes no 

explicit assumption about the policy mechanisms that might be required for adopting the mitigation 

options in different regions. 

Cost estimates are feasible for most greenhouse gas mitigation options in the agricultural sector. This 

report uses an engineering bottom-up approach to estimate the $/tCO2eq of each mitigation option in 

different regions, over different time periods, by including most key elements that affect cost: net 

greenhouse gas effects, changes in crop yield or livestock productivity, regionally specific agricultural 

commodity prices, capital and input costs required to implement the mitigation option, and changes in 

labor requirements. The quality of data and tools used for these input parameters varies by region and by 

agricultural emissions category. 

At the globally aggregated scale (including all regions and all non-CO2 sources), the technical 

potential to mitigate non-CO2 greenhouse gases from agriculture appears significant but not 

overwhelming in percentage terms. At roughly zero costs (where the benefits of implementing the 

mitigation options compensate for the costs of doing so), approximately 10 percent of global agricultural 

non-CO2 emissions can be mitigated. At very high costs around $150/tCO2eq, the technical mitigation 

potential at the global scale approaches 20 percent of baseline emissions. These estimated percentage 

reductions are larger than the previous analysis supported by the USEPA and carried out for EMF-21, but 

these two studies are very different; this report uses more recent baseline scenarios for livestock 

emissions and uses completely different approaches to estimate the baseline and mitigation scenarios 

from croplands and rice cultivation. 

For individual emissions categories, the magnitude of net greenhouse gas mitigation potential 

appears significant to modest depending on region and time frame. For global cropland N2O and soil 

carbon emissions, approximately 15 percent of baseline emissions can be mitigated at zero costs. At costs 

above $50/tCO2eq, the percentage reduction approaches 25 percent. Nitrification inhibitors and no-till 

appear the most viable mitigation options, according to the simulations with the DAYCENT model, with 

regard to net emissions reduction potential and yield effects. The options where baseline nitrogen 

fertilizers are simply reduced result in net emissions similar to baseline levels. 

For Asian rice systems (representing about 90 percent of world rice emissions), close to 15 percent of 

net baseline emissions (CH4, N2O and soil carbon) can be mitigated at zero costs in years 2010 and 2020. 

As costs approach $100/tCO2eq, over 25 percent of net baseline emissions can be mitigated. Shallow 

flooding, ammonium sulfate, and full conversion to midseason drainage appear the most viable 

mitigation options, according to the simulations with the DNDC model, with regard to net emissions 

mitigation potential and yield effects. Upland rice almost eliminates emissions but has adverse yield 

effects. Shallow flooding has the additional benefit of water conservation, though water as an unpriced 

commodity in this context does not factor into the cost estimates. 

For global livestock emissions, approximately 7 percent can be mitigated at zero costs assuming a 

constant number of animals, whereas roughly 9 percent can be mitigated assuming a constant level of 
SECTION V — AGRICULTURE • CONCLUSIONS 

V-66 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 

production. As costs approach $125/tCO2eq, the technical mitigation potential reaches 16 and 18 percent 

of baseline emissions, when, respectively, constant number of animals and constant production are 

assumed. There are somewhat surprisingly few large differences among the mitigation options in terms 

of their non-CO2 mitigation potential at the global scale relative to baseline levels. 

Many mitigation options have negative costs and it is difficult to assess whether important costs have 

been omitted or if barriers to adoption exist that are not accounted for. High-cost options tend to be those 

that are either not very effective at reducing net greenhouse gases or that have adverse yield and 

productivity effects. Adoption barriers have not been explicitly addressed (all mitigation options 

considered technically feasible in a given region are assumed to be adopted in data year 2000). 

Accounting for adoption barriers to gain a more complete picture of greenhouse gas mitigation potential 

is an important area for future research. 

Consideration of net greenhouse gas effects (CH4, N2O, and soil carbon) is particularly important in 

the agricultural sector to evaluate the effectiveness of different mitigation options. This is especially true 

for croplands and rice cultivation. In croplands, options considered a priori to be good candidates for 

reducing soil N2O emissions (e.g., reducing baseline nitrogen application rates) led to no significant net 

greenhouse gas emissions reductions relative to the baseline because of offsetting soil carbon effects. 

Likewise with rice cultivation, some options are good CH4-reducing strategies but increase N2O (e.g., 

midseason drainage), while others have little effect on CH4 but are good N2O-reducing strategies (e.g., 

use of ammonium sulfate under certain conditions). The inclusion of fossil fuel CO2 emissions associated 

with either on-farm practices or off-farm production processes, such as fertilizer production, is an 

additional net greenhouse gas consideration that was not included here. 

The long-lasting benefits of N2O and CH4 reductions relative to the potentially reversible benefits of 

soil carbon sequestration deserve attention. In this report, there is no reversal of soil carbon sequestration 

due to, say, adoption of no till, because this practice is assumed to be adopted immediately and 

continuously through to 2020. 

Estimating mitigation potential of agricultural non-CO2 emissions is challenging at the international 

scale given the high degree of heterogeneity in management and biophysical conditions. Use of process 

models like DAYCENT (for cropland emissions) and DNDC (for rice cultivation emissions) in this report 

can help capture this variability and improve confidence in net greenhouse gas and yield estimates. Use 

of these models at such large scales is intended to show the general trends between baseline and 

mitigation scenarios, while adequately capturing heterogeneous effects. These models are not intended to 

match small-scale (e.g., farm scale) conditions over the entire regions to which they are being applied. 

Livestock baseline emissions are taken from USEPA (2006), which for many regions relies on IPCC 

Tier I default methodologies. Mitigation studies found in the literature are applied to those baselines. 

This approach raises two key issues that need to be addressed in future work: 1) the identification of 

more detailed baseline management activities so that there is more certainty about the implications of 

adopting the mitigation options and 2) the suitability of applying mitigation options to regions outside of 

an original case study area. 

Adoption of the mitigation options in this report would lead to agricultural commodity effects and 

therefore would affect baseline commodity prices, crop area, production levels of crops, and livestock 

populations and livestock products. These changes in turn change greenhouse gas levels and thus the 

effectiveness of the mitigation options. The agricultural market sensitivity experiments with the IMPACT 

model show this to be the case. The core mitigation estimates in this report use a static, engineering 

approach that is unable to capture these market dynamics. For this reason, cost estimates and marginal 

abatement curves are shown using either constant area (livestock population) or constant crop (livestock) 
SECTION V — AGRICULTURE • CONCLUSIONS 

GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES V-67

production. For the livestock sector, where many mitigation options actually increase emissions per 

animal, it is particularly important to show the implications of both approaches; using constant livestock 

production, as expected, leads to greater emissions reduction estimates. Fuller representation of these 

market feedbacks for future global agricultural mitigation analyses will be important. 

Additional research is also necessary to identify which mitigation options are best suited for different 

regions and subregions and what kind of adoption barriers different mitigation options may face. This 

report excludes some options from being applied in certain regions, but further refinement is required. 

Finally, anthropogenic climate change is not considered in this report for the 2000 to 2020 period but 

could affect future agricultural baseline emissions and thus mitigation potential. Anthropogenic climate 

change will become a more important issue for analyses that look beyond 2020. 
SECTION V — AGRICULTURE • CONCLUSIONS 

V-68 GLOBAL MITIGATION OF NON-CO2 GREENHOUSE GASES 
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Zhang, Y., C. Li, C.C. Trettin, H. Li, and G. Sun. 2002. “An Integrated Model of Soil, Hydrology and 

Vegetation for Carbon Dynamics in Wetland Ecosystems.” Global Biogeochemical Cycles 

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Zheng X., M. Wang, Y. Wang, R. Shen, J. Gou, J. Li, J. Jin, and L. Li. 2000. “Impacts of Soil Moisture on 

Nitrous Oxide Emissions from Croplands: A Case Study on the Rice-Based Agro-Ecosystem in 

Southeast China.” Chemosphere-Global Change Science 2, 207–224. 

Zheng, X.H., M.X. Wang, Y.S. Wang, R.X. Shen, X.J. Shangguan, J. Heyer, M. Kögge, H. Papen, J.S. Jin, 

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Section V: Agriculture Sector Appendixes 

Appendixes for this section are available for download from the USEPA’s Web site at 

http://www.epa.gov/nonco2/econ-inv/international.html. 


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