1 

MEMO: UPDATED ESTIMATES OF MONETIZED GHG IMPACTS 

ASSOCIATED WITH THE PROPOSED HEAVY-DUTY AND 

FUEL EFFICIENCY STANDARDS 

1 Introduction 

Subsequent to the signature of the proposed heavy-duty greenhouse (GHG) and fuel 

efficiency standards, the Office of Management and Budget (OMB) posted a revised Technical 

Support Document, Technical Update of the Social Cost of Carbon for Regulatory Impact 

Analysis Under Executive Order 12866 (May 2013, Revised July 2015). Referred to hereafter as 

the “current TSD,” it presents two minor technical corrections to the current estimates of the 

social cost of carbon (SC-CO2).1 One technical correction addressed an inadvertent omission of 

climate change damages in the last year of analysis (2300) in one model and the second 

addressed a minor indexing error in another model. The correction also affects the Marten et al. 

(2014) estimates of the social cost of methane (SC-CH4) and social cost of N2O (SC-N2O), which 

were affected by the same indexing error and were used in a sensitivity analysis examining the 

rulemaking’s non-CO2 GHG impacts. This memo presents the revised estimates of the 

monetized GHG impacts associated with emission reductions expected from the proposed heavyduty GHG and fuel efficiency standards. 

2 Updated Estimates of the SC-CO2, SC-CH4, SC-N2O 

The corrected social cost of CO2, CH4, N2O (collectively, SC-GHG) estimates are shown 

below. On average the revised SC-CO2 estimates are one dollar less than the mean SC-CO2

estimates reported in the November 2013 TSD. The change in the estimates associated with the 

95th percentile estimates when using a 3% discount rate is slightly larger, as those estimates are 

heavily influenced by the results from the model that was affected by the indexing error. The 

percent change in the SC-CH4 and SC-N2O estimates is likewise minor. Table 2-1 presents the 

revised estimates of the SC-CO2 and replaces preamble Table IX-13. Tables 2-2 and 2-3 present 

 

1

 Docket EPA-HQ-OAR-2014-0827, Technical Support Document: Technical Update of the Social Cost of Carbon 

for Regulatory Impact Analysis Under Executive Order 12866, Interagency Working Group on Social Cost of 

Carbon, with participation by Council of Economic Advisers, Council on Environmental Quality, Department of 

Agriculture, Department of Commerce, Department of Energy, Department of Transportation, Domestic Policy 

Council, Environmental Protection Agency, National Economic Council, Office of Management and Budget, 

Office of Science and Technology Policy, and Department of Treasury (May 2013, Revised July 2015). 

Available at: http://www.whitehouse.gov/sites/default/files/omb/inforeg/scc-tsd-final-july-2015.pdf. 
2 

the corrected estimates of the SC-CH4 and SC-N2O, respectively, and replace preamble table IX19. 

Table 2-1 Social Cost of CO2, 2012 – 2050a (in 2012$ per Metric Ton) 

CALENDAR

YEAR 

DISCOUNT RATE AND STATISTIC 

5% Average 3% Average 2.5% Average 3% 

95th percentile 

TSD Version Nov 

2013 

Revised Nov 

2013 

Revised Nov 

2013 

Revised Nov 

2013 

Revised 

2012 $12 $12 $37 $36 $58 $57 $100 $100

2015 12 12 40 39 61 60 120 110

2020 13 13 46 45 69 67 140 130

2025 15 15 51 50 74 73 150 150

2030 17 17 56 54 81 79 170 160

2035 20 19 60 59 86 84 190 180

2040 23 23 66 65 93 91 210 200

2045 26 25 71 69 99 96 220 210

2050 28 28 77 74 100 100 240 230

Note: 

a

 The SC-CO2 values are dollar-year and emissions-year specific and have been rounded to two 

significant digits. The TSDs present SC-CO2 in $2007. The unrounded numbers from the 2013 

TSD and current TSD were adjusted to 2012$ using the GDP Implicit Price Deflator. Also 

available at: http://www.gpo.gov/fdsys/pkg/ECONI-2013-02/pdf/ECONI-2013-02-Pg3.pdf. 

Table 2-2 Social Cost of CH4, 2012 – 2050a (in 2012$ per Metric Ton) 

(Source: Marten et al. (2014)) 

CALENDAR

YEAR 

DISCOUNT RATE AND STATISTIC 

5% Average 3% Average 2.5% Average 3% 

95th percentile 

Sourceb 2014 Correction 2014 Correction 2014 Correction 2014 Correction

2012 $440 $430 $1000 $990 $1400 $1,400 $2800 $2,800

2015 500 490 1200 1,100 1500 1,500 3100 3,000

2020 590 580 1300 1,300 1700 1,700 3500 3,500

2025 710 700 1500 1,500 1900 1,900 4100 4,000

2030 840 820 1700 1,700 2300 2,200 4600 4,500

2035 990 970 2000 1,900 2500 2,500 5400 5,300

2040 1,200 1,100 2300 2,200 2800 2,800 6000 5,900

2045 1,300 1,300 2500 2,500 3100 3,000 6800 6,600

2050 1,500 1,400 2700 2,700 3300 3,300 7400 7,200

Note: 

a

 . Marten et al. (2014) presents estimates, which are emissions-year specific, in $2007. They were 

adjusted to 2012$ using the GDP Implicit Price Deflator and rounded to two significant digits, as 

shown in Marten et al. (2014). GDP Implicit Price Deflator also available at: 

http://www.gpo.gov/fdsys/pkg/ECONI-2013-02/pdf/ECONI-2013-02-Pg3.pdf. 
3 

b

 The rows marked “2014” refer to the original Marten et al. (2014) publication and those marked 

“Correction” refer to the Marten et al. (2014) Erratum submitted to Climate Policy in July 2015. 

The Erratum corrects the estimates. 

Table 2-3 Social Cost of N2O, 2012 – 2050a (in 2012$ per Metric Ton) 

(Source: Marten et al. (2014)) 

CALENDAR 

YEAR 

DISCOUNT RATE AND STATISTIC 

5% Average 3% Average 2.5% Average 3% 

95th percentile 

Sourceb 2014 Correction 2014 Correction 2014 Correction 2014 Correction 

2012 $4000 $3,900 $14000 $13,000 $20000 $20,000 $37000 $35,000

2015 4400 4,300 15000 14,000 22000 22,000 39000 38,000

2020 5200 5,100 16000 16,000 24000 24,000 44000 42,000

2025 6000 5,900 18000 18,000 27000 26,000 50000 47,000

2030 7000 6,800 20000 20,000 29000 29,000 55000 53,000

2035 8100 8,000 23000 23,000 32000 31,000 61000 59,000

2040 9300 9,100 25000 25,000 35000 35,000 67000 65,000

2045 11000 10,000 27000 27,000 38000 37,000 73000 71,000

2050 12000 12,000 29000 29,000 41000 40,000 80000 78,000

Note: 

a

 . Marten et al. (2014) presents estimates, which are emissions-year specific, in $2007. They were 

adjusted to 2012$ using the GDP Implicit Price Deflator and rounded to two significant digits, as 

shown in Marten et al. (2014). GDP Implicit Price Deflator also available at: 

http://www.gpo.gov/fdsys/pkg/ECONI-2013-02/pdf/ECONI-2013-02-Pg3.pdf. 

b

 The rows marked “2014” refer to the original Marten et al. (2014) publication and those marked 

“Correction” refer to the Marten et al. (2014) Erratum submitted to Climate Policy in July 2015. 

The Erratum corrects the estimates. 

3 Updated Estimates of Monetized GHG Impacts from the Proposal 

The approach used to value the proposal’s anticipated GHG impacts, i.e., the application of 

the social cost estimates to changes in emissions, remains the same and is described in detail in 

Chapter 8 of the Regulatory Impact Analysis. For brevity, this memo reports the results of 

applying the revised SC-GHG estimates to the expected changes in emissions. 

The application of the revised SC-CO2 estimates does not change the key findings of the 

economic analysis. The net benefits estimated in each year of the analysis period (2018 through 

2050) remain positive, though decrease slightly (e.g., by 0.19 percent in year 2035 and 0.48 
4 

percent in year 2050 when using the central SC-CO2).2 Likewise, the proposed rulemaking’s 

annual benefit estimates, i.e., the sum of GHG and non-GHG benefits in a certain year, decrease 

when using the corrected SC-CO2 estimates (e.g., by 0.49 percent in 2035 and 1.2 percent in 

2050 when using the central SC-CO2). 

Tables 3-1 through 3-4 present the revised summaries of benefits and net benefit estimates 

of the proposed rule, hereby replacing an Executive Summary table from the preamble and 

preamble Tables IX-34, IX-35, and IX-36, respectively. In Tables 3-1 through 3-4, the estimates 

published in the preamble are shown in parentheses next to the revised estimates; only one 

number is shown if the preamble estimates were not affected. 

Table 3-1 Summary of the Proposed Phase 2 Medium- and Heavy-Duty Vehicle Annual Fuel and GHG 

Reductions, Program Costs, Benefits and Net Benefits in Calendar Years 2035 and 2050, Based on Analysis 

Method Ba

2035 

(preamble) revised 

2050 

(preamble) revised

Fuel Reductions (Billion Gallons) 9.3 13.4 

GHG Reduction (MMT, CO2-Eq) 127.1 183.4 

Vehicle Program Costs (including Maintenance; 

Billions of 2012$) 

-$6.0 -$7.1 

Fuel Savings (Pre-Tax; Billions of 2012$) $37.2 $57.5 

Benefits (Billions of 2012$) ($20.5) $20.4 ($32.9) $32.5 

Net Benefits (Billions of 2012$) ($51.7) $51.6 ($83.2) $82.8 

Notes: 

a

 Benefits and net benefits use the 3 percent average SCC-CO2 value applied only to CO2 emissions; GHG 

reductions include CO2, CH4, N2O and HFC reductions; values reflect the preferred alternative relative to the 

less dynamic baseline (a reference case that projects very little improvement in new vehicle fuel economy 

absent new standards). 

 

 

2

 The central SC-CO2 is the model average SC-CO2 estimate at a 3 percent discount rate. The percent change in net 

benefits and benefits are calculated using rounded values in the table. 
5 

Table 3-2 Annual Benefits & Costs of the Preferred Alternative and Net Present Values at 3% and 7% 

Discount Rates using Method B and Relative to the Less Dynamic Baseline (Billions of 2012$) a

 2018 2021 2024 2030 2035 2040 2050 NPV, 

3% 

NPV, 

7% 

Vehicle program -$0.1 -$2.4 -$3.7 -$5.4 -$5.9 -$6.3 -$7.0 -$86.8 -$41.1

Maintenance $0.0 $0.0 -$0.1 -$0.1 -$0.1 -$0.1 -$0.1 -$1.8 -$0.9

Pre-tax fuel $0.2 $1.7 $6.9 $24.0 $37.2 $47.8 $57.5 $495.6 $206.7

Energy security $0.0 $0.1 $0.3 $1.3 $2.2 $2.9 $3.5 $28.9 $11.9

Accidents/Congestion/Noise $0.0 -$0.1 -$0.3 -$0.5 -$0.7 -$0.8 -$0.9 -$9.3 -$4.2

Refueling impacts $0.0 $0.0 $0.1 $0.4 $0.7 $0.9 $1.2 $9.4 $3.9

Travel value $0.0 $0.4 $1.0 $1.9 $2.4 $2.9 $3.3 $34.2 $15.3

Non-GHG impacts $0.0 

to 

$0.1 

$0.4 

to 

$0.9 

$1.0 to 

$2.4 

$3.3 to 

$8.3 

$4.8 to 

$12.1 

$5.7 to 

$14.3 

$7.0 to 

$17.5

$69.7 to 

$157.0 

$26.6 to 

$60.4

SCCb,c 

SCC_CO2; 5% Avg $0.0 $0.1 $0.4 $1.5 ($2.5)

$2.4 

$3.3 $5.0 ($22.1)

$21.6 

($22.1)

$21.6

SCC_CO2; 3% Avg $0.0 $0.3 $1.3 ($4.8)

$4.6 

($7.4)

$7.3 

($9.7)

$9.5 

($13.6)

$13.2

($103.1)

$100.7 

($103.1)

$100.7

SCC_CO2; 2.5% Avg $0.1 $0.5 $1.9 ($6.9)

$6.7 

($10.6)

$10.3 

($13.7)

$13.3 

($18.5)

$18.1

($164.1)

$160.3 

($164.1)

$160.3

SCC_CO2; 3% 95th $0.1 $1.0 ($4.0)

$3.9 

($14.6)

$13.9 

($23.2)

$22.2 

($30.3)

$29.1 

($42.0)

$40.5

($320.5)

$307.5 

($320.5)

$307.5

Net benefits d 

SCC_CO2; 5% Avg $0.2 $0.4 ($6.4)

$6.3 

$28.8 ($46.8) 

$46.7 

$60.6 $74.6 ($605.8) 

$605.2 

($257.1) 

$256.6

SCC_CO2; 3% Avg $0.2 $0.7 $7.3 ($32.1) 

$31.9 

($51.7) 

$51.6 

($66.9) 

$66.8 

($83.2) 

$82.8

($686.8) 

$684.3 

$335.6

SCC_CO2; 2.5% Avg $0.2 $0.8 $7.9 ($34.2) 

$34.0 

($54.9) 

$54.7 

($70.9) 

$70.6 

($88.2) 

$87.8

($747.8) 

$743.9

$395.3

SCC_CO2; 3% 95th $0.3 $1.3 ($10.0) 

$9.8 

($41.9) 

$41.3

($67.5) 

$66.6

($87.6) 

$86.3

($111.7) 

$110.2

($904.1) 

$891.1

$542.4

Notes: The estimates published in the preamble are shown in parentheses next to the revised estimates; only one 

number is shown if the preamble estimates were not affected. 

a

 Positive values denote decreased social costs (benefits); negative values denote increased social costs. For an 

explanation of analytical Methods A and B, please see Section I.D; for an explanation of the less dynamic baseline, 

1a, and more dynamic baseline, 1b, please see Section X.A.1. 
6 

b

 Net present value of reduced CO2 emissions is calculated differently than other benefits. The same discount rate 

used to discount the value of damages from future emissions (SC-CO2 at 5, 3, 2.5 percent) is used to calculate net 

present value of SC-CO2for internal consistency. Refer to the SCC TSD for more detail. 

cSection IX.G notes that SC-CO2 increases over time. For the years 2012-2050, the SC-CO2 estimates range as 

follows: for Average SC-CO2 at 5%: $12-$28; for Average SC-CO2 at 3%: $36-$75; for Average SC-CO2 at 2.5%: 

$57-$103; and for 95th percentile SC-CO2 at 3%: $100-$230. Section IX.G also presents these SC-CO2 estimates. 

d

 Net impacts are the summation of results within columns of the table with the exception that the net impacts at 

each SC-CO2 value include only the SC-CO2 impacts at that value. 

Table 3-3 Discounted Model Year Lifetime Benefits & Costs of the Preferred Alternative using Method B and 

Relative to the Less Dynamic Baseline (Billions of 2012$ discounted at 3%) a 

 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027 2028 2029 SUM 

Vehicle 

program 

-

$0.1

-

$0.1

-$0.1 -$2.0 -$1.9 -$1.9 -$2.8 -$2.7 -$2.7 -$3.7 -$3.6 -$3.5 -$25.1

Maintenance -

$0.1

$0.0 $0.0 -$0.1 -$0.1 -$0.1 -$0.1 -$0.1 -$0.1 -$0.1 -$0.1 -$0.1 -$1.1

Pre-tax fuel $1.9 $1.9 $1.8 $11.1 $11.5 $11.9 $18.9 $19.6 $20.2 $24.1 $24.1 $24.1 $171.1

Energy 

security 

$0.1 $0.1 $0.1 $0.5 $0.6 $0.6 $1.0 $1.1 $1.1 $1.4 $1.4 $1.4 $9.3

Accidents/ 

Congestion/ 

Noise 

-

$0.1

-

$0.1

-$0.2 -$0.4 -$0.4 -$0.4 -$0.4 -$0.4 -$0.4 -$0.4 -$0.4 -$0.4 -$4.2

Refueling $0.0 $0.0 $0.0 $0.2 $0.2 $0.2 $0.3 $0.3 $0.4 $0.5 $0.5 $0.5 $3.1

Travel value $0.6 $0.6 $0.7 $1.5 $1.5 $1.5 $1.4 $1.4 $1.4 $1.4 $1.4 $1.4 $14.9

Non-GHG $0.2 

to 

$0.5

$0.2 

to 

$0.4

$0.2 

to 

$0.4

$2.0 to 

$4.5

$2.0 to 

$4.5

$2.0 to 

$4.5

$2.9 to 

$6.6

$3.0 to 

$6.8

$2.6 to 

$5.9

$3.1 to 

$6.9

$3.1 to 

$6.9

$3.1 to 

$7.0

$24.4 to 

$55.0

SCC b,c

 

SCC_CO2; 

5% Avg 

$0.1 $0.1 $0.1 $0.5 $0.5 $0.5 ($0.9) 

$0.8

$0.9 $0.9 $1.1 $1.1 $1.1 ($7.8) 

$7.6

SCC_CO2; 

3% Avg 

$0.4 $0.4 $0.4 ($2.2) 

$2.1

($2.3) 

$2.2

$2.3 ($3.7) 

$3.6

($3.9) 

$3.8

($4.0) 

$3.9

($4.8) 

$4.7

($4.8) 

$4.7

($4.9) 

$4.7

($34.0) 

$33.2

SCC_CO2; 

2.5% Avg 

$0.6 $0.6 ($0.6) 

$0.5

($3.4) 

$3.3

($3.5) 

$3.4

$3.6 ($5.8) 

$5.7

($6.1) 

$6.0

($6.3) 

$6.2

($7.6) 

$7.4

($7.6) 

$7.5

($7.7) 

$7.5

($53.4) 

$52.2

SCC_CO2; 

3% 95th 

$1.1 $1.1 $1.1 ($6.6) 

$6.4

($6.9) 

$6.6

($7.2) 

$6.9

($11.5) 

$11.0

($12.0) 

$11.5

($12.4) 

$11.9

($14.9) 

$14.3

($15.0) 

$14.4

($15.1) 

$14.5

($105.0) 

$100.7

Net benefits

d

 

SCC_CO2; 

5% Avg 

$2.8 $2.7 $2.7 $14.6 $15.1 $15.5 $23.9 $25.0 $25.1 $29.2 ($29.4) 

$29.3

$29.4 ($215.5) 

$215.3

SCC_CO2; 

3% Avg 

$3.0 $3.0 $3.0 $16.2 $16.8 $17.3 ($26.8) 

$26.7

($28.0) 

$27.9

($28.2) 

$28.1

($33.0) 

$32.8

($33.1) 

$33.0

($33.2) 

$33.1

($241.7) 

$240.9

SCC_CO2; 

2.5% Avg 

$3.2 $3.2 $3.2 $17.4 ($18.1) 

$18.0

($18.6) 

$18.5

($28.9) 

$28.8

($30.2) 

$30.0

($30.5) 

$30.4

($35.7) 

$35.6

($35.9) 

$35.8

($36.0) 

$35.9

($261.1) 

$259.9

SCC_CO2; 

3% 95th 

$3.8 $3.7 $3.7 ($20.7) 

$20.4

($21.5) 

$21.2

($22.1) 

$21.9

($34.5) 

$34.1

($36.0) 

$35.6

($36.6) 

$36.1

($43.1) 

$42.4

($43.3) 

$42.7

($43.5) 

$42.8

($312.7) 

$308.4

Notes: The estimates published in the preamble are shown in parentheses next to the revised estimates; only one 

number is shown if the preamble estimates were not affected. 

a

 Positive values denote decreased social costs (benefits); negative values denote increased social costs. For an 

explanation of analytical Methods A and B, please see Section I.D; for an explanation of the less dynamic baseline, 

1a, and more dynamic baseline, 1b, please see Section X.A.1.c 
7 

b Net present value of reduced CO2 emissions is calculated differently than other benefits. The same discount rate 

used to discount the value of damages from future emissions (SC-CO2 at 5, 3, 2.5 percent) is used to calculate net 

present value of SC-CO2 for internal consistency. Refer to the SCC TSD for more detail. 

c Section IX.G notes that SCC increases over time. For the years 2012-2050, the SC-CO2 estimates range as follows: 

for Average SC-CO2 at 5%: $12-$28; for Average SC-CO2 at 3%: $36-$75; for Average SC-CO2 at 2.5%: $57-

$103; and for 95th percentile SC-CO2 at 3%: $100-$230. Section IX.G also presents these SC-CO2 estimates. 

Section IX.G also presents these SCC estimates. 

d

 Net impacts are the summation of results within columns of the table with the exception that the net impacts at 

each SC-CO2 value include only the SCCO2 impacts at that value. 

Table 3-4 Discounted Model Year Lifetime Benefits & Costs of the Preferred Alternative using Method B

and Relative to the Less Dynamic Baseline (Billions of 2012$ discounted at 7%) a 

 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027 2028 2029 SUM 

Vehicle 

program 

-

$0.1 

-

$0.1

-$0.1 -$1.6 -$1.4 -$1.4 -$1.9 -$1.8 -$1.7 -$2.3 -$2.1 -$2.0 -$16.6

Maintenance $0.0 $0.0 $0.0 -$0.1 -$0.1 -$0.1 -$0.1 -$0.1 -$0.1 -$0.1 -$0.1 $0.0 -$0.6

Pre-tax fuel $1.4 $1.3 $1.2 $6.9 $6.9 $6.8 $10.5 $10.4 $10.4 $11.9 $11.5 $11.0 $90.1

Energy 

security 

$0.1 $0.1 $0.1 $0.3 $0.3 $0.4 $0.5 $0.6 $0.6 $0.7 $0.7 $0.6 $4.8

Accidents/ 

Congestion/ 

Noise 

-

$0.1 

-

$0.1

-$0.1 -$0.3 -$0.3 -$0.2 -$0.2 -$0.2 -$0.2 -$0.2 -$0.2 -$0.2 -$2.4

Refueling $0.0 $0.0 $0.0 $0.1 $0.1 $0.1 $0.2 $0.2 $0.2 $0.2 $0.2 $0.2 $1.6

Travel value $0.4 $0.4 $0.4 $0.9 $0.9 $0.8 $0.8 $0.8 $0.7 $0.7 $0.7 $0.6 $8.2

Non-GHG $0.1 

to 

$0.3 

$0.1 

to 

$0.3

$0.1 

to 

$0.3 

$1.1 to 

$2.5

$1.1 to 

$2.4

$1.0 to 

$2.3

$1.4 to 

$3.3

$1.4 to 

$3.2

$1.2 to 

$2.7

$1.3 to 

$3.0

$1.3 to 

$2.9

$1.3 to 

$2.8

$11.5 to 

$26.0

SCC b,c 

SCC_CO2; 

5% Avg 

$0.1 $0.1 $0.1 $0.5 $0.5 $0.5 ($0.9) 

$0.8 

$0.9 $0.9 $1.1 $1.1 $1.1 ($7.8) 

$7.6

SCC_CO2; 

3% Avg 

$0.4 $0.4 $0.4 ($2.2) 

$2.1 

($2.3) 

$2.2 

$2.3 ($3.7) 

$3.6 

($3.9) 

$3.8 

($4.0) 

$3.9 

($4.8) 

$4.7 

($4.8) 

$4.7 

($4.9) 

$4.7 

($34.0) 

$33.2

SCC_CO2; 

2.5% Avg 

$0.6 $0.6 ($0.6) 

$0.5 

($3.4) 

$3.3 

($3.5) 

$3.4 

$3.6 ($5.8) 

$5.7 

($6.1) 

$6.0 

($6.3) 

$6.2 

($7.6) 

$7.4 

($7.6) 

$7.5 

($7.7) 

$7.5 

($53.4) 

$52.2

SCC_CO2; 

3% 95th 

$1.1 $1.1 $1.1 ($6.6) 

$6.4 

($6.9) 

$6.6 

($7.2) 

$6.9 

($11.5) 

$11.0 

($12.0) 

$11.5 

($12.4) 

$11.9 

($14.9) 

$14.3 

($15.0) 

$14.4 

($15.1) 

$14.5 

($105.0) 

$100.7

Net benefits d 

SCC_CO2; 

5% Avg 

$1.9 $1.8 $1.7 $8.7 $8.7 $8.7 ($13.0) 

$12.9 

$13.1 $12.7 ($14.3) 

$14.2 

$13.8 $13.4 ($111.8) 

$111.6

SCC_CO2; 

3% Avg 

$2.2 $2.1 $2.0 $10.3 $10.4 ($10.5) 

$10.4

($15.8) 

$15.7

($16.1) 

$16.0

($15.8) 

$15.7

($18.0) 

$17.9

($17.6) 

$17.5

($17.2) 

$17.1

($138.0) 

$137.2

SCC_CO2; 

2.5% Avg 

$2.4 $2.3 $2.2 $11.5 ($11.7) 

$11.6

($11.8) 

$11.7

($17.9) 

$17.8

($18.3) 

$18.2

($18.1) 

$18.0

($20.7) 

$20.6

($20.4) 

$20.2

($20.0) 

$19.8

($157.4) 

$156.2

SCC_CO2; 

3% 95th 

$2.9 $2.8 ($2.8) 

$2.7 

($14.8) 

$14.5

($15.1) 

$14.8

($15.3) 

$15.0

($23.6) 

$23.1

($24.2) 

$23.7)

($24.2) 

$23.7

($28.1) 

$27.5

($27.8) 

$27.2

($27.4) 

$26.8

($209.0) 

$204.7

Notes: The estimates published in the preamble are shown in parentheses next to the revised estimates; only one 

number is shown if the preamble estimates were not affected. 

a

 Positive values denote decreased social costs (benefits); negative values denote increased social costs. For an 

explanation of analytical Methods A and B, please see Section I.D; for an explanation of the less dynamic baseline, 

1a, and more dynamic baseline, 1b, please see Section X.A.1.c 
8 

b Net present value of reduced CO2 emissions is calculated differently than other benefits. The same discount rate 

used to discount the value of damages from future emissions (SC-CO2 at 5, 3, 2.5 percent) is used to calculate net 

present value of SC-CO2 for internal consistency. Refer to the SCC TSD for more detail. 

c Section IX.G notes that SCC increases over time. For the years 2012-2050, the SC-CO2 estimates range as follows: 

for Average SC-CO2 at 5%: $12-$28; for Average SC-CO2 at 3%: $36-$75; for Average SC-CO2 at 2.5%: $57-

$103; and for 95th percentile SC-CO2 at 3%: $100-$230. Section IX.G also presents these SC-CO2 estimates. 

Section IX.G also presents these SCC estimates. 

d

 Net impacts are the summation of results within columns of the table with the exception that the net impacts at 

each SC-CO2 value include only the SCCO2 impacts at that value. 

Tables 3-5 and 3-6 present the revised estimates of the monetized benefits associated with 

CO2 reductions for the calendar year and model year analyses, respectively. Tables 3-5 and 3-6 

replace preamble Tables IX-14 and IX-15, respectively. 

Table 3-5 Upstream and Downstream Annual CO2 Benefits for the Given SC-CO2 Valuea using 

Method B and Relative to the Less Dynamic Baseline (Millions of 2012$)b 

CALENDAR 

YEAR 

5% 

AVERAGE 

3% 

AVERAGE 

2.5% 

AVERAGE 

3%, 

95TH PERCENTILE 

2018 $13 $43 $64 $120

2019 $26 $89 $130 $260

2020 $40 $140 $200 $410

2021 $92 $320 $490 $970

2022 $170 $570 $850 $1,700

2023 $250 $840 $1,200 $2,500

2024 $370 $1,300 $1,900 $3,900

2025 $540 $1,800 $2,600 $5,300

2026 $670 $2,300 $3,300 $6,800

2027 $890 $2,900 $4,200 $8,500

2028 $1,100 $3,500 $5,000 $10,000

2029 $1,200 $4,000 $5,900 $12,000

2030 $1,500 $4,600 $6,700 $14,000

2035 $2,400 $7,300 $10,000 $22,000

2040 $3,300 $9,500 $13,000 $29,000

2050 $5,000 $13,000 $18,000 $41,000

NPV $22,000 $100,000 $160,000 $310,000

Notes: 

a The SC-CO2 values are dollar-year and emissions-year specific. 

b For an explanation of analytical Methods A and B, please see preamble Section I.D; for an 

explanation of the less dynamic baseline, 1a, and more dynamic baseline, 1b, please see 

preamble Section X.A.1. 
9 

Table 3-6 Upstream and Downstream Discounted Model Year Lifetime CO2 Benefits for the Given 

SC-CO2 Value using Method B and Relative to the Less Dynamic Baseline (Millions of 2012$)a, b

MODEL 

YEAR 

5% 

AVERAGE 

3% 

AVERAGE 

2.5% 

AVERAGE 

3%, 

95TH PERCENTILE 

2018 $92 $370 $570 $1,100

2019 $88 $360 $560 $1,100

2020 $85 $350 $550 $1,100

2021 $510 $2,100 $3,300 $6,400

2022 $520 $2,200 $3,400 $6,600

2023 $530 $2,300 $3,600 $6,900

2024 $850 $3,600 $5,700 $11,000

2025 $870 $3,800 $6,000 $11,000

2026 $900 $3,900 $6,200 $12,000

2027 $1,100 $4,700 $7,400 $14,000

2028 $1,100 $4,700 $7,500 $14,000

2029 $1,100 $4,700 $7,500 $14,000

Sum $7,600 $33,000 $52,000 $100,000

Notes: 

a The SC-CO2 values are dollar-year and emissions-year specific. 

 b For an explanation of analytical Methods A and B, please see preamble Section I.D; for an 

explanation of the less dynamic baseline, 1a, and more dynamic baseline, 1b, please see 

preamble Section X.A.1. 

The non-CO2 benefit estimates shown in the proposed rulemaking’s sensitivity analysis 

have also been revised using the corrected SC-GHG estimates. The sensitivity analysis 

presented non-CO2 GHG benefits based on two approaches, the Global Warming Potential 

(GWP) approximation approach and the use of directly modeled estimates of the SC-CH4 and 

SC-N2O. The methodology for these two approaches remains the same and is described in detail 

in Chapter 8 of the Regulatory Impact Analysis. 

Tables 3-7 to 3-9 in this memo replace preamble Tables IX-16 to IX-18, which present 

benefit estimates based on the Global Warming Potential (GWP) approximation approach. Table 

3-10 in this memo replaces preamble Table IX-20, which presents the updated CH4 and N2O 

benefit estimates based on corrected estimates of the directly modeled SC-CH4 and SC-N2O. 
10 

Table 3-7 Annual Upstream and Downstream CH4 Benefits for the Given SC-CO2 Value using 

Method B and Relative to the Less Dynamic Baseline, Using the GWP Approacha,b (Millions of 

2012$) b

 CH4

Calendar 

Year 

5% 

Average 

3% 

Average 

2.5% 

Average 

3%, 

95th Percentile

2018 $0.3 $1.1 $1.6 $3.0

2019 $0.6 $2.2 $3.2 $6.4

2020 $1.0 $3.4 $5.0 $10

2021 $3.1 $11 $16 $32

2022 $6 $20 $30 $59

2023 $9 $30 $44 $89

2024 $13 $45 $66 $130

2025 $19 $61 $90 $180

2026 $23 $78 $110 $230

2027 $30 $97 $140 $290

2028 $36 $120 $170 $350

2029 $41 $130 $200 $400

2030 $49 $150 $220 $460

2035 $78 $240 $340 $730

2040 $110 $310 $430 $950

2050 $160 $430 $590 $1,300

NPV $710 $3,300 $5,300 $10,000

Notes: 

a The SC-CO2 values are dollar-year and emissions-year specific 

b

 For an explanation of analytical Methods A and B, please see preamble 

Section I.D; for an explanation of the less dynamic baseline, 1a, and 

more dynamic baseline, 1b, please see preamble Section X.A.1. 

. 

Table 3-8 Annual Upstream and Downstream N2O Benefits for the Given SC-CO2 Value using 

Method B and Relative to the Less Dynamic Baseline, Using the GWP Approacha,b (Millions of 

2012$)b 

 N2O 

Calendar 

Year 

5% 

Average 

3% 

Average 

2.5% 

Average 

3%, 

95th Percentile

2018 $0.0 $0.0 $0.1 $0.1

2019 $0.0 $0.1 $0.2 $0.3

2020 $0.0 $0.2 $0.2 $0.5

2021 $0.1 $0.4 $0.5 $1.0

2022 $0.2 $0.6 $0.9 $1.9

2023 $0.3 $0.9 $1.4 $2.7

2024 $0.4 $1.4 $2.1 $4.2

2025 $0.6 $1.9 $2.9 $5.8

2026 $0.7 $2.5 $3.7 $7.5

2027 $1.0 $3.2 $4.6 $10

2028 $1.2 $3.9 $5.6 $12

2029 $1.4 $4.5 $6.6 $14

2030 $1.6 $5.1 $7.5 $16

2035 $2.7 $8 $12 $25

2040 $3.8 $11 $15 $33
11 

2050 $5.6 $15 $20 $46

NPV $24 $110 $180 $350

Notes: 

a

 The SC-CO2 values are dollar-year and emissions-year specific. 

b For an explanation of analytical Methods A and B, please see 

preamble Section I.D; for an explanation of the less dynamic 

baseline, 1a, and more dynamic baseline, 1b, please see preamble 

Section X.A.1. 

Table 3-9 Annual Upstream and Downstream HFC-134a Benefits for the Given SC-CO2 Value 

using Method B and Relative to the Less Dynamic Baseline, Using the GWP Approacha,b (Millions 

of 2012$)b 

 HFC-134A 

Calendar 

Year 

5% 

Average 

3% 

Average 

2.5% 

Average 

3%, 

95th Percentile

2018 $0.0 $0.0 $0.0 $0.0

2019 $0.0 $0.0 $0.0 $0.0

2020 $0.0 $0.0 $0.0 $0.0

2021 $0.2 $0.8 $1.2 $2.5

2022 $0.5 $1.7 $2.5 $5.1

2023 $0.8 $2.6 $3.8 $7.8

2024 $1.0 $3.6 $5.2 $11

2025 $1.4 $4.6 $6.8 $14

2026 $1.7 $5.7 $8.4 $17

2027 $2.2 $6.9 $10 $21

2028 $2.5 $8.2 $12 $24

2029 $2.8 $9 $14 $28

2030 $3.4 $11 $16 $32

2035 $4.9 $15 $21 $46

2040 $6.1 $18 $25 $53

2050 $8.4 $22 $31 $69

NPV $43 $200 $320 $610

Notes: 

a The SC-CO2 values are dollar-year and emissions-year specific. 

b For an explanation of analytical Methods A and B, please see 

preamble Section I.D; for an explanation of the less dynamic 

baseline, 1a, and more dynamic baseline, 1b, please see preamble 

Section X.A.1. 
12 

Table 3-10 Annual Upstream and Downstream non-CO2 GHG Benefits for the Given SC-non-CO2 

Value using Method B and Relative to the Less Dynamic Baseline, Using the Directly Modeled 

Approacha,b (Millions of 2012$)c

 

YEA

R 

SC-CH4 SC-N2O 

5%

Average 

3%

Average 

2.5%

Average 

3%

95th

percentile 

5%

Average 

3% 

Average 

2.5% 

Average 

3%

95th

percentile 

2018 $0.5 $1.2 $1.6 $3.2 $0.0 $0.1 $0.1 $0.2

2019 $1.1 $2.5 $3.3 $6.6 $0.0 $0.1 $0.2 $0.3

2020 $1.7 $3.9 $5.2 $10 $0.1 $0.2 $0.3 $0.5

2021 $5.7 $13 $17 $34 $0.1 $0.4 $0.6 $1.1

2022 $11 $24 $31 $63 $0.2 $0.8 $1.1 $2.0

2023 $16 $36 $47 $95 $0.4 $1.1 $1.6 $2.9

2024 $25 $54 $70 $140 $0.6 $1.7 $2.5 $4.5

2025 $34 $74 $95 $200 $0.8 $2.4 $3.4 $6.2

2026 $44 $95 $120 $250 $1.0 $3.1 $4.4 $8.0

2027 $56 $120 $150 $310 $1.3 $4.0 $5.6 $10

2028 $68 $140 $180 $380 $1.6 $4.8 $6.8 $12

2029 $80 $170 $210 $450 $1.9 $5.7 $8.1 $15

2030 $92 $190 $240 $510 $2.2 $6.5 $9.3 $17

2035 $160 $310 $400 $850 $3.7 $10 $14 $27

2040 $210 $410 $540 $1,100 $5.0 $14 $19 $36

2050 $320 $620 $770 $1,700 $7.9 $20 $27 $52

NPV $1,400 $4,500 $6,300 $12,000 $33 $150 $230 $380

Notes: 

a The values are emissions-year specific and have been rounded to two significant digits. Unrounded numbers were 

used to calculate the GHG benefits. 

b Note that net present discounted values of reduced GHG emissions are calculated differently than other benefits. 

The same discount rate used to discount the value of damages from future emissions (SC-CH4 and SC- N2O at 5, 3, 

and 2.5 percent) is used to calculate net present value discounted values of SC-CH4 and SC- N2O for internal 

consistency. Refer to SCC TSD for more detail. 

c For an explanation of analytical Methods A and B, please see preamble Section I.D; for an explanation of the less 

dynamic baseline, 1a, and more dynamic baseline, 1b, please see preamble Section X.A.1. 

4 References 

Technical Support Document: Technical Update of the Social Cost of Carbon for Regulatory Impact 

Analysis Under Executive Order 12866, Interagency Working Group on Social Cost of Carbon, with 

participation by Council of Economic Advisers, Council on Environmental Quality, Department of 

Agriculture, Department of Commerce, Department of Energy, Department of Transportation, 

Environmental Protection Agency, National Economic Council, Office of Energy and Climate Change, 

Office of Management and Budget, Office of Science and Technology Policy, and Department of 

Treasury (May 2013, Revised July 2015). Available at: 

http://www.whitehouse.gov/sites/default/files/omb/inforeg/scc-tsd-final-july-2015.pdf.