16-i 

CHAPTER 16. MONETIZATION OF EMISSION REDUCTIONS BENEFITS 

TABLE OF CONTENTS

16.1 INTRODUCTION ............................................................................................................ 16-1

16.2 MONETIZING CARBON DIOXIDE EMISSIONS ........................................................ 16-1

16.2.1 Social Cost of Carbon ........................................................................................... 16-1

16.2.2 Social Cost of Carbon Values Used in Past Regulatory Analyses ........................ 16-2

16.2.3 Current Approach and Key Assumptions ............................................................. 16-3

16.3 VALUATION OF OTHER EMISSIONS REDUCTIONS .............................................. 16-6

LIST OF TABLES

Table 16.2.1 Social Cost of CO2, 2010–2050 ............................................................................ 16-5
16-1 

CHAPTER 16. MONETIZATION OF EMISSION REDUCTIONS BENEFITS 

16.1 INTRODUCTION

As part of its assessment of energy conservation standards for automatic commercial ice 

makers, the U.S. Department of Energy (DOE) will estimate the monetary benefits likely to 

result from the reduced emissions of carbon dioxide (CO2) and nitrogen oxides (NOX) that are 

expected to result from each of the trial standard levels (TSLs) to be considered. In order to make 

this calculation similar to the calculation of the net present value (NPV) of consumer benefit, 

DOE will consider the reduced emissions expected to result over the lifetime of products shipped 

in the forecast period for each TSL. This chapter summarizes the basis for the monetary values to 

be used for each of these emissions. 

16.2 MONETIZING CARBON DIOXIDE EMISSIONS

16.2.1 Social Cost of Carbon 

 Under section 1(b) of Executive Order 12866, Regulatory Planning and Review, 58 FR 

51735 (Oct. 4, 1993), agencies must, to the extent permitted by law, “assess both the costs and 

the benefits of the intended regulation and, recognizing that some costs and benefits are difficult 

to quantify, propose or adopt a regulation only upon a reasoned determination that the benefits of 

the intended regulation justify its costs.” 

 The purpose of the social cost of carbon (SCC) estimates presented here is to allow 

Federal agencies to incorporate the monetized social benefits of reducing CO2 emissions into 

cost-benefit analyses of regulatory actions that have small, or “marginal,” impacts on cumulative 

global emissions. The estimates are presented with an acknowledgement of the many 

uncertainties involved and with a clear understanding that they should be updated over time to 

reflect increasing knowledge of the science and economics of climate impacts.

 As part of the interagency process that developed these SCC estimates, technical experts 

from numerous agencies met on a regular basis to consider public comments, explore the 

technical literature in relevant fields, and discuss key model inputs and assumptions. The main 

objective of this process was to develop a range of SCC values using a defensible set of input 

assumptions grounded in the existing scientific and economic literatures. In this way, key 

uncertainties and model differences transparently and consistently inform the range of SCC 

estimates used in the rulemaking process.

The SCC is an estimate of the monetized damages associated with an incremental 

increase in carbon emissions in a given year. It is intended to include (but is not limited to) 

changes in net agricultural productivity, human health, property damages from increased flood 

risk, and the value of ecosystem services. Estimates of the SCC are provided in dollars per metric 

ton of CO2. 
16-2 

When attempting to assess the incremental economic impacts of CO2 emissions, the 

analyst faces a number of serious challenges. A recent report from the National Research 

Councila

 points out that any assessment will suffer from uncertainty, speculation, and lack of 

information about (1) future emissions of greenhouse gases, (2) the effects of past and future 

emissions on the climate system, (3) the impact of changes in climate on the physical and 

biological environment, and (4) the translation of these environmental impacts into economic 

damages. As a result, any effort to quantify and monetize the harms associated with climate 

change will raise serious questions of science, economics, and ethics and should be viewed as 

provisional. 

Despite the serious limits of both quantification and monetization, SCC estimates can be 

useful in estimating the social benefits of reducing CO2 emissions. Consistent with the directive 

quoted above, the purpose of the SCC estimates presented here is to make it possible for 

agencies to incorporate the social benefits from reducing CO2 emissions into cost-benefit 

analyses of regulatory actions that have small, or “marginal,” impacts on cumulative global 

emissions. Most Federal regulatory actions can be expected to have marginal impacts on global 

emissions.

For such policies, the agency can estimate the benefits from reduced (or costs from 

increased) emissions in any future year by multiplying the change in emissions in that year by 

the SCC value appropriate for that year. The net present value of the benefits can then be 

calculated by multiplying each of these future benefits by an appropriate discount factor and 

summing across all affected years. This approach assumes that the marginal damages from 

increased emissions are constant for small departures from the baseline emissions path, an 

approximation that is reasonable for policies that have effects on emissions that are small relative 

to cumulative global CO2 emissions. For policies that have a large (non-marginal) impact on 

global cumulative emissions, there is a separate question of whether the SCC is an appropriate 

tool for calculating the benefits of reduced emissions. DOE does not attempt to answer that 

question here. 

It is important to emphasize that the interagency process is committed to updating these 

estimates as the science and economic understanding of climate change and its impacts on 

society improves over time. Specifically, the interagency group has set a preliminary goal of 

revisiting the SCC values within two years or at such time as substantially updated models 

become available, and to continue to support research in this area. In the meantime, the 

interagency group will continue to explore the issues raised by this analysis and consider public 

comments as part of the ongoing interagency process. 

16.2.2 Social Cost of Carbon Values Used in Past Regulatory Analyses 

 To date, economic analyses for Federal regulations have used a wide range of values to 

estimate the benefits associated with reducing CO2 emissions. In the final model year 2011 

CAFE rule, the Department of Transportation (DOT) used both a “domestic” SCC value of $2 

 

a National Research Council. Hidden Costs of Energy: Unpriced Consequences of Energy Production and Use. 

National Academies Press: Washington, D.C. 2009. 
16-3 

per ton of CO2 and a “global” SCC value of $33 per ton of CO2 for 2007 emission reductions (in 

2007 dollars), increasing both values at 2.4 percent per year.b It also included a sensitivity 

analysis at $80 per ton of CO2. A domestic SCC value is meant to reflect the value of damages 

in the United States resulting from a unit change in CO2 emissions, while a global SCC value is 

meant to reflect the value of damages worldwide.

 A 2008 regulation proposed by DOT assumed a domestic SCC value of $7 per ton of CO2

(in 2006 dollars) for 2011 emission reductions (with a range of $0-$14 for sensitivity analysis), 

also increasing at 2.4 percent per year.c

 A regulation for packaged terminal air conditioners and 

packaged terminal heat pumps finalized by DOE in October 2008 used a domestic SCC range of 

$0 to $20 per ton CO2 for 2007 emission reductions (in 2007 dollars). 73 FR 58772, 58814 

(Oct. 7, 2008) In addition, the U.S. Environmental Protection Agency’s (EPA’s) 2008 Advance 

Notice of Proposed Rulemaking for Greenhouse Gases identified what it described as “very 

preliminary” SCC estimates subject to revision.d EPA’s global mean values were $68 and $40 

per ton CO2 for discount rates of approximately 2 percent and 3 percent, respectively (in 2006 

dollars for 2007 emissions). 

 In 2009, an interagency process was initiated to offer a preliminary assessment of how 

best to quantify the benefits from reducing CO2 emissions. To ensure consistency in how 

benefits are evaluated across agencies, the Administration sought to develop a transparent and 

defensible method, specifically designed for the rulemaking process, to quantify avoided climate 

change damages from reduced CO2 emissions. The interagency group did not undertake any 

original analysis. Instead, it combined SCC estimates from the existing literature to use as 

interim values until a more comprehensive analysis could be conducted. The outcome of the 

preliminary assessment by the interagency group was a set of five interim values: global SCC 

estimates for 2007 (in 2006 dollars) of $55, $33, $19, $10, and $5 per ton of CO2. 

These interim values represent the first sustained interagency effort within the U.S. 

Government to develop an SCC for use in regulatory analysis. The results of this preliminary 

effort were presented in several proposed and final rules and were offered for public comment in 

connection with proposed rules, including the joint EPA-DOT fuel economy and CO2 tailpipe 

emission proposed rules. See CAFE Rule for Passenger Cars and Light Trucks Draft EIS and 

Final EIS, cited above.

16.2.3 Current Approach and Key Assumptions

 Since the release of the interim values, the interagency group reconvened on a regular 

basis to generate improved SCC estimates, which will be considered for this proposed rule. 

Specifically, the group considered public comments and further explored the technical literature 

 

b See Average Fuel Economy Standards Passenger Cars and Light Trucks Model Year 2011, 74 FR 14196 (March 

30, 2009); Final Environmental Impact Statement Corporate Average Fuel Economy Standards, Passenger Cars and 

Light Trucks, Model Years 2011-2015 at 3-90 (Oct. 2008) (Available at: www.nhtsa.gov/fuel-economy). c See Average Fuel Economy Standards, Passenger Cars and Light Trucks, Model Years 2011-2015, 73 FR 24352 

(May 2, 2008); Draft Environmental Impact Statement Corporate Average Fuel Economy Standards, Passenger Cars 

and Light Trucks, Model Years 2011-2015 at 3-58 (June 2008) (Available at: www.nhtsa.gov/fuel-economy).

d See Regulating Greenhouse Gas Emissions Under the Clean Air Act, 73 FR 44354 (July 30, 2008).
16-4 

in relevant fields. The interagency group relied on three integrated assessment models commonly 

used to estimate the SCC: the FUND, DICE, and PAGE models.e These models are frequently 

cited in the peer-reviewed literature and were used in the last assessment of the 

Intergovernmental Panel on Climate Change. Each model was given equal weight in the SCC 

values that were developed. 

Each model takes a slightly different approach to model how changes in emissions result 

in changes in economic damages. A key objective of the interagency process was to enable a 

consistent exploration of the three models while respecting the different approaches to 

quantifying damages taken by the key modelers in the field. An extensive review of the literature 

was conducted to select three sets of input parameters for these models: (1) climate sensitivity; 

(2) socio-economic and emissions trajectories; and (3) discount rates. A probability distribution 

for climate sensitivity was specified as an input into all three models. In addition, the interagency 

group used a range of scenarios for the socio-economic parameters and a range of values for the 

discount rate. All other model features were left unchanged, relying on the model developers’ 

best estimates and judgments.

 The interagency group selected four SCC values for use in regulatory analyses. Three 

values are based on the average SCC from three integrated assessment models, at discount rates 

of 2.5, 3, and 5 percent. The fourth value, which represents the 95th percentile SCC estimate 

across all three models at a 3-percent discount rate, is included to represent higher-than-expected 

impacts from temperature change further out in the tails of the SCC distribution. For emissions 

(or emission reductions) that occur in later years, these values grow in real terms over time, as 

depicted in Table 16.2.1. Additionally, the interagency group determined that a range of values 

from 7 percent to 23 percent should be used to adjust the global SCC to calculate domestic 

effects,f

 although preference is given to consideration of the global benefits of reducing CO2

emissions. 

 

e The models are described in appendix 16A of the preliminary technical support document.

f It is recognized that this calculation for domestic values is approximate, provisional, and highly speculative. There 

is no a priori reason why domestic benefits should be a constant fraction of net global damages over time.
16-5 

Table 16.2.1 Social Cost of CO2, 2010–2050 

Discount Rate

2007$ per metric ton

5%

Avg

3%

Avg

2.5%

Avg

3%

95th

2010 4.7 21.4 35.1 64.9

2015 5.7 23.8 38.4 72.8

2020 6.8 26.3 41.7 80.7

2025 8.2 29.6 45.9 90.4

2030 9.7 32.8 50.0 100.0

2035 11.2 36.0 54.2 109.7

2040 12.7 39.2 58.4 119.3

2045 14.2 42.1 61.7 127.8

2050 15.7 44.9 65.0 136.2

 It is important to recognize that a number of key uncertainties remain, and that current 

SCC estimates should be treated as provisional and revisable since they will evolve with 

improved scientific and economic understanding. The interagency group also recognizes that the 

existing models are imperfect and incomplete. The National Research Council report mentioned

above points out that there is tension between the goal of producing quantified estimates of the 

economic damages from an incremental ton of carbon and the limits of existing efforts to model 

these effects. There are a number of concerns and problems that should be addressed by the 

research community, including research programs housed in many of the agencies participating 

in the interagency process to estimate the SCC.

 DOE recognizes the uncertainties embedded in the estimates of the SCC used for costbenefit analyses. As such, DOE and others in the U.S. Government intend to periodically review 

and reconsider those estimates to reflect increasing knowledge of the science and economics of 

climate impacts, as well as improvements in modeling. In this context, statements recognizing 

the limitations of the analysis and calling for further research take on exceptional significance.

In summary, in considering the potential global benefits resulting from reduced CO2

emissions, DOE used the most recent SCC values identified by the interagency process, adjusted 

to 2010$ using the GDP price deflator. For each of the four cases specified, the values used for 

emissions in 2010 were $4.9, $22.3, $36.5, and $67.6 per metric ton avoided (values expressed in 

2010$). To monetize the CO2 emissions reductions expected to result from amended standards 

for automatic commercial ice makers, DOE will use the values identified in Table A1 of the 

“Social Cost of Carbon for Regulatory Impact Analysis Under Executive Order 12866,” which is 

reprinted in appendix 16A of this preliminary technical support document, appropriately 

escalated to 2010$.g To calculate a present value of the stream of monetary values, DOE will

discount the values in each of the four cases using the specific discount rate that had been used to 

obtain the SCC values in each case. 

 

g Table A1 presents SCC values through 2050. For DOE’s calculation, it derived values after 2050 using the 

3-percent per year escalation rate used by the interagency group.
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16.3 VALUATION OF OTHER EMISSIONS REDUCTIONS

DOE will consider the potential monetary benefit of reduced NOX emissions from the 

TSLs it considers. As noted in chapter 15, new or amended energy conservation standards would 

reduce NOX emissions in those 22 states that are not affected by the Clean Air Interstate Rule, in 

addition to the reduction in site NOX emissions nationwide. DOE will estimate the monetized 

value of NOX emissions reductions resulting from each of the TSLs considered based on 

environmental damage estimates from the literature. Available estimates suggest a very wide 

range of monetary values, ranging from $370 per ton to $3,800 per ton of NOX from stationary 

sources, measured in 2001$ (equivalent to a range of $451 to $4,635 per ton in 2010$).h In 

accordance with Office of Management and Budget (OMB) guidance, DOE will conduct two 

calculations of the monetary benefits using each of the above values used for NOX, one using a 

real discount rate of 3 percent and another using a real discount rate of 7 percent.i 

DOE is aware of multiple agency efforts to determine the appropriate range of values 

used in evaluating the potential economic benefits of reduced Hg emissions. DOE has decided to 

await further guidance regarding consistent valuation and reporting of Hg emissions before it 

once again monetizes Hg in its rulemakings. 

 

h For additional information, refer to U.S. Office of Management and Budget, Office of Information and Regulatory 

Affairs, 2006 Report to Congress on the Costs and Benefits of Federal Regulations and Unfunded Mandates on 

State, Local, and Tribal Entities, Washington, D.C.

i

OMB, Circular A-4: Regulatory Analysis (Sept. 17, 2003).