•Numerous US electric utilities have announced voluntary emission reduction pledges•1/7 of pledged reductions may be achieved under existing state and regional policies•Pledges may further achieve reductions equal to 1/3 of 2018 US power sector emissions•Consistency in pledge documentation and tracking is needed to ensure transparency The power sector contributes about one-quarter of total US greenhouse gas (GHG) emissions. Although the Biden administration has committed to a transition to carbon-free electricity by 2035, the US has historically lacked binding federal climate policies. Numerous electric utilities have announced their own GHG emission reduction pledges, but the amount of additional emission reductions they might achieve remains unclear. Here, we examine 36 major utility pledges announced as of December 2020 across 80 separate subsidiaries and operating territories. While some pledged reductions seem to duplicate reductions encouraged by existing state and regional policies, these pledges, should they all be met, nonetheless have the potential to generate net emissions reduction equivalent to 32% of 2018 US power sector emissions. Greater consistency in both pledge and emissions reporting will also be necessary to ensure transparency and to help design policies that build on existing efforts. The power sector represents 25% of US total greenhouse gas (GHG) emissions. In the absence of comprehensive federal climate policies, numerous US electric utilities have announced GHG reduction pledges. The extent to which they can mitigate emissions beyond existing state and regional policies remains unclear, however. Here we compile 36 major utility pledges in place as of December 2020 across more than 80 utility subsidiaries and operating territories and compare pledged reductions with those achievable under existing state and regional renewable energy production or emission reduction requirements. We show that one-seventh of utility pledged reductions may already occur under existing state and regional policies but nonetheless have the potential for substantial net emissions reductions, an amount equivalent to one-third of 2018 US power sector emissions. Although challenges remain to tracking achievement of pledged reductions, voluntary reduction efforts could play a vital role in climate change mitigation. The power sector represents 25% of US total greenhouse gas (GHG) emissions. In the absence of comprehensive federal climate policies, numerous US electric utilities have announced GHG reduction pledges. The extent to which they can mitigate emissions beyond existing state and regional policies remains unclear, however. Here we compile 36 major utility pledges in place as of December 2020 across more than 80 utility subsidiaries and operating territories and compare pledged reductions with those achievable under existing state and regional renewable energy production or emission reduction requirements. We show that one-seventh of utility pledged reductions may already occur under existing state and regional policies but nonetheless have the potential for substantial net emissions reductions, an amount equivalent to one-third of 2018 US power sector emissions. Although challenges remain to tracking achievement of pledged reductions, voluntary reduction efforts could play a vital role in climate change mitigation. Representing 25% of total greenhouse gas (GHG) emissions both in the US and globally, the power sector is the single largest contributor to global GHG emissions and therefore represents an important locus of mitigation efforts.1Bruckner T. Bashmakov I.A. Mulugetta Y. Chum H. de la Vega Navarro A. Edmonds J. et al.Energy systems.in: Edenhofer O. Pichs-Madruga R. Sokona Y. Farahani E. Kadner S. Seyboth K. Climate Change 2014: Mitigation of Climate Change. Contribution of Working Group III to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge University Press, 2014: 511-597Google Scholar,2de Coninck H. Revi A. Babiker M. Bertoldi P. Buckeridge M. Cartwright A. et al.Strengthening and implementing the global response.in: MassonDelmotte V. Zhai P. Pörtner H.-O. Roberts D. Skea J. Shukla P.R. Global Warming of 1.5°C. An IPCC Special Report on the Impacts of Global Warming of 1.5°C above Pre-industrial Levels and Related Global Greenhouse Gas Emission Pathways, in The Context of Strengthening the Global Response to the Threat of Climate Change, Sustainable Development, and Efforts to Eradicate Poverty. IPCC, 2018: 313-443Google Scholar In 2018, the US power sector emitted approximately 1,764 million metric tons of carbon dioxide equivalent (MtCO2e),3US Energy Information Administration (USEIA)Energy-related carbon dioxide emissions, 2019.https://www.eia.gov/environment/emissions/carbon/Date: 2020Google Scholar itself reflecting a reduction of more than 25% since 2005.4US Energy Information Administration (USEIA)Today in energy.https://www.eia.gov/todayinenergy/detail.php?id=37392Date: 2018Google Scholar New technological advances paired with policies that encourage low- or no-emitting technologies have been credited with the shift in GHG emissions.4US Energy Information Administration (USEIA)Today in energy.https://www.eia.gov/todayinenergy/detail.php?id=37392Date: 2018Google Scholar Yet, despite recent progress, GHG emission reductions have not occurred at the pace or magnitude deemed necessary to avert the most serious impacts of climate change.2de Coninck H. Revi A. Babiker M. Bertoldi P. Buckeridge M. Cartwright A. et al.Strengthening and implementing the global response.in: MassonDelmotte V. Zhai P. Pörtner H.-O. Roberts D. Skea J. Shukla P.R. Global Warming of 1.5°C. An IPCC Special Report on the Impacts of Global Warming of 1.5°C above Pre-industrial Levels and Related Global Greenhouse Gas Emission Pathways, in The Context of Strengthening the Global Response to the Threat of Climate Change, Sustainable Development, and Efforts to Eradicate Poverty. IPCC, 2018: 313-443Google Scholar,5IPCCSummary for policymakers.in: Masson-Delmotte V. Zhai P. Pirani A. Connors S.L. Péan C. Berger S. Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge University Press, 2021: 3-31Google Scholar Examples of ambitious climate initiatives exist at the US state and local levels, but remain scattered in the absence of a comprehensive climate policy at the federal level, providing the impetus for GHG mitigation through voluntary private governance in the interim.6Vandenbergh M.P. Gilligan J.M. Beyond Politics. Cambridge University Press, 2017Crossref Scopus (57) Google Scholar, 7Vandenbergh M.P. Metzger D.J. Private governance responses to climate change: the case of global civil aviation.Fordham Environ. Law Rev. 2018; 30: 62-110Google Scholar, 8Banda M.L. The bottom-up alternative: the mitigation potential of private climate governance after the Paris agreement.Harv. Environ. Law Rev. 2018; 42: 325-389Google Scholar, 9Hale T.N. Chan S. Hsu A. Clapper A. Elliott C. Faria P. et al.Sub-and non-state climate action: a framework to assess progress, implementation and impact.Clim. Policy. 2020; 21: 406-420Crossref Scopus (28) Google Scholar While public policy plays an irreplaceable role in global GHG mitigation efforts, private sector actions can be important complements, especially given the capability of corporations to act more rapidly than governments in dealing with complex issues like climate change.10Gilligan J.M. Vandenbergh M.P. A framework for assessing the impact of private climate governance.Energy Res. Social Sci. 2020; 60: 101400Crossref Scopus (20) Google Scholar As pressure from consumers and public sentiment mount, these attributes have created additional pathways to promote GHG mitigation through both individual private sector actions and broader societal movements.10Gilligan J.M. Vandenbergh M.P. A framework for assessing the impact of private climate governance.Energy Res. Social Sci. 2020; 60: 101400Crossref Scopus (20) Google Scholar,11Gunningham N. Smart mixes, non-state governance and climate change.in: van Erp J. Faure M. Nollkaemper A. Philipsen N. Smart Mixes for Transboundary Environmental Harm. Cambridge University Press, 2019: 239-258Crossref Scopus (1) Google Scholar Electric utilities have long used voluntary governance as a means to reduce GHG emissions and to preempt regulation.12Welch E. Mazur A. Bretschneider S. Voluntary behavior by electric utilities: levels of adoption and contribution of the climate challenge program to the reduction of carbon dioxide.J. Policy Anal. Manag. 2000; 19: 407-425Crossref Scopus (129) Google Scholar While such voluntary efforts can further legitimize voluntary action and garner coalitional support by nongovernmental organizations and other subsystem actors,13Bernstein S. Cashore B. Can non-state global governance be legitimate? An analytical framework.Regul. Gov. 2007; 1: 347-371Crossref Google Scholar voluntary agreements that serve to replace public policy mandates raise questions of transparency, accountability, and enforcement,14Blackman A. Lyon T.P. Sisto N. Voluntary environmental agreements when regulatory capacity is weak.Comp. Econ. Stud. 2006; 48: 682-702Crossref Google Scholar not to mention the potential for free-ridership or shifts of emissions to outside the voluntary regime (i.e., leakage). The Climate Challenge Program under the Clinton administration was found to be ineffective at reducing emissions, for example, when accounting for late joiners who displayed only symbolic cooperation.15Delmas M. Montes-Sancho M. Voluntary agreements to improve environmental quality: symbolic and substantive cooperation.Strateg. Manag. J. 2009; 31: 575-601Google Scholar In the continued absence of a comprehensive federal GHG mitigation policy in the United States, a new round of voluntary action by power sector actors has recently taken place. In December 2018, Xcel Energy became what was reported to be the country’s first major utility to announce a decarbonization pledge.16Pyper J. Xcel energy commits to 100% carbon-free electricity by 2050.https://www.greentechmedia.com/articles/read/xcel-commits-to-100-carbon-free-electricity-by-20501Date: 2018Google Scholar In the short time since that announcement, nearly 5 dozen utilities have announced carbon reduction pledges, with service areas that reach much of the United States.17Smart Electric Power Alliance (SEPA)Utility carbon reduction tracker.https://sepapower.org/utility-transformation-challenge/utility-carbon-reduction-tracker/Date: 2020Google Scholar The results of the 2020 elections arguably heightened the importance of such private sector governance approaches. A central campaign promise of the Biden administration was the aggressive decarbonization of the US power sector. That includes a target of “a carbon pollution-free power sector by 2035,” which would require a steep acceleration of recent trends toward clean electricity.18Biden-HarrisThe Biden plan to build a modern, sustainable infrastructure and an equitable clean energy future.https://joebiden.com/clean-energy/#Date: 2020Google Scholar As of the time of this writing, new legislation to facilitate sector-wide decarbonization, such as a price on carbon or a clean electricity standard, remain politically challenging given the slim majority in the US Senate. Indeed, the recent removal of regulatory initiatives to decarbonize the power sector from a budget reconciliation package, a central mechanism to achieve the Biden administration’s GHG reduction goal, underscores the need to determine the feasibility of achieving equivalent reductions through other means.19Davenport C. Key to Biden’s Climate Agenda Likely to Be Cut Because of Manchin Opposition. The Washington Post, 2021https://www.nytimes.com/2021/10/15/climate/biden-clean-energy-manchin.htmlGoogle Scholar Efforts to regulate GHGs in the power sector under the existing language of the Clean Air Act are themselves likely to be opposed in court, as evidenced by challenges levied against both the Clean Power Plan under the Obama administration and the Affordable Clean Energy rule under the Trump administration.20Mufson S. Federal court scraps Trump Administration’s power plant rule.https://www.washingtonpost.com/climate-environment/2021/01/19/federal-circuit-court-scraps-trump-administration-power-plant-rules/Date: 2021Google Scholar Stringent state-level climate policies, while important, remain absent in certain parts of the country.21Database of State Incentives for Renewables & Efficiency (DSIRE)https://www.dsireusa.org/Date: 2020Google Scholar Private sector action, including from electric utilities, may therefore remain a key driver of progress in the coming years. Recent research has endeavored to catalog pledges as they are announced22Clean Air Task Force (CATF)State and utility decarbonization commitments.https://www.catf.us/2020/10/state-and-regional-decarbonization-commitments/Date: 2020Google Scholar and to explore the progress being made toward existing utility pledges given individual regulatory filings.23Porter S. Thomsom J. Motyka M. LaCroix C. Hardin K. Amon C. Utility Decarbonization Strategies: Renew, Reshape, and Refuel to Zero. Deloitte Development, LLC, 2020Google Scholar,24Romankiewicz J. Bottorff C. Stokes L.C. The Dirty Truth About Utility Climate Pledges. Sierra Club, 2020https://www.sierraclub.org/sites/www.sierraclub.org/files/blog/Final%20Greenwashing%20Report%20%281.22.2021%29.pdfGoogle Scholar Elsewhere, analysis has evaluated the performance of individual utility pledges against GHG reduction targets set by the Biden administration.25Pomerantz D. Kasper M. Many U.S. Electric Utilities Plan Slow Decarbonization over Next Decade, Out of Sync with Biden Plan. Energy and Policy Institute, 2020https://www.energyandpolicy.org/utilities-carbon-goal-biden-climate-plan/Google Scholar Pomerantz and Kasper,25Pomerantz D. Kasper M. Many U.S. Electric Utilities Plan Slow Decarbonization over Next Decade, Out of Sync with Biden Plan. Energy and Policy Institute, 2020https://www.energyandpolicy.org/utilities-carbon-goal-biden-climate-plan/Google Scholar for instance, analyzed the pledged reductions of 22 major electric utilities, finding generally that individual company pledges were failing to keep pace with Biden administration climate targets. In both Porter et al.23Porter S. Thomsom J. Motyka M. LaCroix C. Hardin K. Amon C. Utility Decarbonization Strategies: Renew, Reshape, and Refuel to Zero. Deloitte Development, LLC, 2020Google Scholar and Romankiewicz et al.,24Romankiewicz J. Bottorff C. Stokes L.C. The Dirty Truth About Utility Climate Pledges. Sierra Club, 2020https://www.sierraclub.org/sites/www.sierraclub.org/files/blog/Final%20Greenwashing%20Report%20%281.22.2021%29.pdfGoogle Scholar the authors find that utility progress toward meeting individual pledged reductions were lagging based on the slow pace of coal retirements and the planned addition of new natural gas assets. Analyses such as these are important to assess the continued progress of individual utilities in meeting their pledged reductions. What has yet to emerge is a comprehensive accounting of what these utility pledges—assuming they are met—might collectively achieve in terms of aggregate GHG emission reductions. While at first appearing a simple matter of arithmetic, such an exercise is complicated by a number of practical data gathering and accounting challenges. Utility pledges are highly individualized, context dependent, and collectively difficult to document,25Pomerantz D. Kasper M. Many U.S. Electric Utilities Plan Slow Decarbonization over Next Decade, Out of Sync with Biden Plan. Energy and Policy Institute, 2020https://www.energyandpolicy.org/utilities-carbon-goal-biden-climate-plan/Google Scholar complicating efforts to directly aggregate and compare. FirstEnergy (one of the country’s largest investor-owned utilities), for example, includes its auto fleet in its pledges and limits other reductions to units under its direct control.26St. John J. FirstEnergy’s carbon-reduction pledge lacks clear path to cutting coal use.https://www.greentechmedia.com/articles/read/firstenergys-carbon-neutral-by-2050-pledge-lacks-clear-path-to-cutting-coal-useDate: 2020Google Scholar PG&E has expressed support for state-level renewable energy and GHG reduction goals, while pledging to reduce its own emissions by 1 MtCO2e. Other utilities (AES, Entergy, NextEra) have expressed their reduction goals in terms of emissions intensity. A second challenge is the presence of state clean energy or GHG reduction policies that might themselves contribute to utility emissions reductions over time. Stated another way, the question remains as to whether utility pledges simply track what would have otherwise been required—either in part or in whole—under existing state policies, or whether their pledges represent new, additional emissions reductions. A related question is whether and to what extent the presence of existing state clean energy or GHG reduction requirements influences the contribution of utility pledges in a given state (i.e., whether pledges play a larger role in GHG reductions in some states versus others). Finally, the question remains of how total net pledged reductions compare with national-level emissions and GHG reduction targets, and whether the path by which utilities choose to meet their pledged reductions influences the magnitude of cumulative emissions reductions over time. Although many utilities have both long-term and interim reduction targets, the question remains as to the path by which each pledged target is met. Answering each of these questions is necessary to assess the viability and contribution of voluntary utility pledges as part of a broader GHG mitigation strategy such as those currently being deliberated upon in the United States and elsewhere.9Hale T.N. Chan S. Hsu A. Clapper A. Elliott C. Faria P. et al.Sub-and non-state climate action: a framework to assess progress, implementation and impact.Clim. Policy. 2020; 21: 406-420Crossref Scopus (28) Google Scholar Here, we evaluate the gross and net aggregate emission reduction implications associated with 36 utility GHG reduction pledges announced as of December 8, 2020 (Figure 1). We further disaggregate reductions across more than 80 utility subsidiaries and operating territories, and compare pledged reductions with reductions under existing state renewable energy and GHG mitigation requirements. We estimate that one-seventh of pledged reductions are already required under existing state and regional policies. Utility pledges nonetheless have the potential for substantial net emissions reductions, an amount equivalent to one-third of year 2018 US power sector emissions. While questions remain as to willingness and capacity to meet future pledged reductions, our analysis highlights gaps utility pledges may fill in states without renewable or GHG mitigation requirements while also underscoring the challenge to quantifying mitigation potential and tracking progress toward meeting pledged targets. Gross pledged reductions for the utilities included in this analysis were estimated to be approximately 653 MtCO2e per year, which is roughly 84% of these utilities’ 2018 emissions. Subtracting the obligations of utilities from reductions implicit in state-level clean energy and GHG reduction policies lowered net emission reductions to approximately 563 MtCO2e per year, or roughly 72% of total 2018 emissions from pledging utilities (Table 1). Assuming our attribution of existing versus future compliance obligations under state-level energy policy was reasonably accurate, this difference between estimated gross and net emission reductions suggests that nearly one-seventh of pledged emission reductions are already expected to occur under existing law.Table 1Calculated distribution of gross and net utility pledges relative to power sector and total US emissionsRelative annual emission reductions%Net emission reductions, gross utility pledged reduction86%Net emission reductions, 2018 pledging utility emissions72%Net emission reductions, 2018 power sector total emissions32%Net emission reductions, US 2018 net GHG emissions (emissions + sequestration)10%Net emission reductions, US 2018 gross GHG emissions (emissions only)8% Open table in a new tab Our analysis likewise indicates that private governance initiatives cover a substantial fraction of total GHG emissions from the US power sector. Although the 36 utilities and their various subsidiaries included in this analysis represent a small fraction of the nearly 3,000 investor-owned utilities (IOUs), municipal utilities, and rural electric cooperatives operating in the United States,27US Energy Information Administration (USEIA)Investor-owned utilities served 72% of U.S. electricity customers in 2017.https://www.eia.gov/todayinenergy/detail.php?id=40913Date: 2019Google Scholar they nonetheless represent many of the largest utilities in terms of customer base and were collectively responsible for 44% of 2018 US power sector emissions. The net pledged reductions offered by these 36 utilities are likewise significant, estimated to be equivalent to approximately 32% of 2018 US power sector emissions. As a share of total US emissions, these pledged reductions equate to more than 8% of gross emissions or approximately 10% of emissions when accounting for land-based sequestration. Looking forward, data from the US Energy Information Administration (USEIA)28US Energy Information Administration (USEIA)Annual Energy Outlook, 2020; Table 18. Energy-related carbon dioxide emissions by sector and source.https://www.eia.gov/outlooks/aeo/Date: 2020Google Scholar suggest that, under current policies, net power sector emissions could decrease between now and 2050, with emissions in that year projected to be approximately 1,346 MtCO2e. Comparing this projected total with 2018 emissions gives a potential indication of the decarbonization trend already expected in the power sector over the coming decades. As power sector emissions are already projected to decline by nearly 24% between 2018 and 2050, it is possible that the reductions represented by the pledges assessed here (approximately 32%) could be at least partially accounted for by expected decarbonization within the sector itself, assuming reductions are allocated equally across the sector. It is also possible that, given their relative size and resources, the utilities evaluated here are able to reduce more rapidly or to a greater extent than the sector mean, in which case the pledged reductions estimated here represent additional mitigation capable of supplementing projected sector-wide declines. The findings detailed above reflect annual emission reductions in the years they are pledged. Informative as these metrics are, they obscure several important details about the utility pledges assessed here. The first is geographical distribution (Figure 2). Arraying gross and net emission reductions by the states in which utility customers are located suggests that a large share of net emission reductions may occur in areas of the country in which there are currently no state-level renewable energy or GHG reduction standards (e.g., Georgia, Alabama, Indiana, Florida). Also notable is the influence of stringent state renewable energy goals in reducing the net contribution of utility pledges elsewhere (e.g., Virginia, Colorado, California). Other interesting findings include a peculiar situation in Ohio, where net reductions are actually higher than gross reductions owing to the sunsetting of that state’s renewable portfolio standard in 2027. We again underscore the influence of our approach for allocating emissions to particular states on specific emissions estimates, but nonetheless expect general trends to be robust to these assumptions. An additional consideration is the timing by which utilities may achieve these reductions. Although the final endpoint may remain the same, the pace of emissions reductions has implications for cumulative emission reductions. A majority of utility pledges assessed here include interim targets as well as endpoint targets. Even with these markers to guide emission reductions over time, there is still uncertainty over the path by which they could be met. Shown in Figure 3 are two stylized pathways by which utilities may reach their pledged targets. The first (Figure 3A) represents continuous linear progress toward meeting pledged reductions, whereas the second (Figure 3B) represents delayed action followed by rapid adoption and subsequent leveling off, a pattern often associated with the diffusion of new technologies.29Geroski P.A. Models of technology diffusion.Res. Policy. 2000; 29: 603-625Crossref Scopus (845) Google Scholar In reality, emission reductions are likely to follow a blocked, step function, as fossil units are retired and renewable or clean generation is brought online. What these stylized curves nonetheless do show is that a more even path, characterized by early and consistent progress toward emission reduction goals (Figure 3A), is capable of much greater cumulative emissions reductions than a path where implementation is delayed but later accelerates (Figure 3B). We estimate the cumulative difference between the two curves to be approximately 817 MtCO2e between now and 2050, a difference of roughly 8%, pointing to relevance of strong interim targets in the intervening years. A related set of considerations raised by our analysis is the process by which pledges are met, whether they will be met, and whether they will be met on time. Most important, our analysis assumes that utility pledges will be met in the time frame proposed. Recent analysis has cast doubt on whether the pace of utility transformation thus far is matching the pace necessary to meet pledged reductions.23Porter S. Thomsom J. Motyka M. LaCroix C. Hardin K. Amon C. Utility Decarbonization Strategies: Renew, Reshape, and Refuel to Zero. Deloitte Development, LLC, 2020Google Scholar,24Romankiewicz J. Bottorff C. Stokes L.C. The Dirty Truth About Utility Climate Pledges. Sierra Club, 2020https://www.sierraclub.org/sites/www.sierraclub.org/files/blog/Final%20Greenwashing%20Report%20%281.22.2021%29.pdfGoogle Scholar As a reviewer of an earlier version of this article noted, there is likewise a mismatch between the short- and medium-term planning horizon represented in Integrated Resource Planning (IRP) and similar regulatory processes and the long-term nature of many of the pledged reductions evaluated here. A related complexity is reflected in the state renewable or clean energy standards we use to estimate each utility’s emission baseline, specifically the presence of caps on compliance costs that, if reached, could serve to decrease the state’s target for clean electricity sales. For these reasons, continued efforts are necessary to cross-walk and compare the incremental operational decisions being made by utilities, the extent to which those decisions contribute to meeting pledged reductions, and the extent to which pledged reductions go beyond what would have otherwise been required. Another implementation consideration is the use of offsets in the context of net-zero pledges. In these situations, a given utility may purchase reductions by a third party to effectively cancel out its own remaining emissions. Carbon offsets have long been a part of climate deliberations, but questions have been raised about the appropriateness and rigor of offsets both as a general climate mitigation strategy,30Cullenward D. Victor D.G. Making Climate Policy Work. Polity Press, 2020Google Scholar as well as in the specific context of utility GHG reduction efforts.31Saul J. Duke Plans Carbon Offsets for 5% of Emissions to Reach Net Zero. Bloomberg Green, 2021https://www.bloomberg.com/news/articles/2021-06-23/duke-plans-carbon-offsets-for-5-of-emissions-to-reach-net-zeroGoogle Scholar As we are focused on the magnitude of pledged reductions and not the mechanism by which those reductions occur, the question of whether offsets are a viable strategy for utility GHG reduction falls outside the scope of our analysis. What can be said, however, is that the use of offsets brings additional actors into utility GHG reduction efforts, potentially complicating efforts to track progress toward pledged reductions. There are also more nuanced aspects of corporate leadership in broader climate governance initiatives to consider, such as who is participating and their incentives for doing so. The top-heavy nature of pledged reductions evaluated here—two utilities (Duke and Southern) account for roughly one-third of gross pledged reductions, while the 10 largest pledged reductions comprise nearly three-quarters of the gross total—suggests that efforts to monitor or enforce pledges might begin with a narrower subset of actors. As the combined emissions intensity associated with the two largest utilities assessed here is already lower than the power sector as a whole,32US Energy Information Administration (USEIA)Emissions by plant and by region.https://www.eia.gov/electricity/data/emissions/Date: 2020Google Scholar,33US Environmental Protection Agency (USEPA)Emissions & generation resource integrated database (eGRID).https://www.epa.gov/egrid/download-dataDate: 2020Google Scholar an additional implication is that the largest pledging utilities might be in a favorable position to further reduce emissions relative to nonpledging utilitie