I. Executive Summary

The recent rescinding of the 2009 EPA Endangerment Finding under the Trump Administration has resulted in concerns raised by stakeholders over public health, environmental protection, and the future of the US. Various key environmental policies, including the Clean Air Act and regulations involving vehicle and technology transition, have been heavily impacted by the rescission. There are potential policy changes that may prevent some of the harm, including strengthening state-level climate policies, congressional legislative action, and grassroots and market-based initiatives.

II. History

The history of modern U.S. climate policy starts with the 2007 Supreme Court case, Massachusetts v. EPA. This Supreme Court case ruled that greenhouse gases qualified as air pollutants under the Clean Air Act. This meant the EPA now had to determine whether these gas emissions posed a threat to public health and welfare.  This caused some stir amongst politicians regarding the impact of climate change on policies. So, the government decided to address this in 2009 with the Endangerment Finding. The EPA issued this finding during President Barack Obama’s first term, determining that the six GHGs threatened public health, welfare, and the environment through excessive air pollution. This was regulated under Section 202(a) of the Clean Air Act and soon became the legal foundation of U.S. climate regulation and policymaking. This allowed the government to set standards and limits for power plants, vehicles, emission regulations, and federal climate policy frameworks and committees. Along with this finding came intense debate surrounding climate policy; for example, the cap and trade legislation (which aims to reduce GHGs by setting a cap on total pollution and issuing tradable allowances) didn’t pass in Congress in 2010. This showed just how divisive the climate issue was, but reinforced why it was so necessary. In February 2026, the EPA officially rescinded the finding, marking a regressive shift in U.S. environmental policy. This shift came under President Trump, who is currently in his second term. Additionally, the EPA repealed GHG emission standards for light, medium, and heavy-duty vehicles. Consequently, the EPA is no longer required to regulate GHG, significantly weakening the authority of the Clean Air Act. President Trump described it as “the largest deregulatory action in American history”. Supporters of the bill argue the reversal could save a projected $1.3 T in regulatory costs, and that enforcing the finding would lead to increased costs for consumers and businesses. They also note how the reversal prioritizes energy independence and economic competitiveness.  Critics of the reversal emphasize how it contradicts decades of climate research, and especially highlight that increased climate disasters will occur, drawing more costs from the relief fund. Many environmental organizations and 24 state governments, including Massachusetts, California, and New York, have now issued lawsuits against the EPA, arguing the illegality of the reversal in affecting climate protection duties. Throughout the Trump administration, the retreat from international climate discussions has been glaringly apparent, such as the past absence of the U.S. at COP31, weakening global cooperation and progress.

A. Stakeholders

This reversal has created various negative effects for multiple stakeholders. Fossil fuel companies largely support deregulation as it reduces compliance costs and removes restrictions on emissions. Alternatively, it leaves them more vulnerable to increased climate-related lawsuits without federal protections. Policymakers continue to be divided as the climate policy issue remains predominantly led by democrats. Some tend to prioritize economic growth and reduced regulatory burden, while others prioritize public health protections and global climate agreements. Corporations, communities, policymakers, climate experts, etc. Meanwhile, climate experts and scientific organizations such as NASA and NOAA largely support the 2009 finding. These organizations continue to confirm GHG rising emission data, and experts warn that the reversal separates the science connection from the climate conversation, and creates uncertainty in how the U.S. will approach climate issues moving forward.

III. Impact on Communities

EPA’s regulations of the spillover effect of the repeal not only affect the federal government but also have persisting impacts on local communities. Some of the impacts include the shift in costs and risks onto households, local governments, and local communities with the absence of spillover regulations. The change in regulations also weakens protections for local transportation, as all GHG emission standards for new motor vehicles and engines are repealed. With the progressing regulations weakening green gas regulations, this also worsens climate burdens, including but not limited to causing an increase in food prices, higher energy bills, natural disasters, and rising healthcare and insurance costs. Yet, these burdens do not fall evenly on all parties. Often, they greatly impact low-income households and communities vulnerable to climate change. 

Regulations on greenhouse gas emissions post-reversal also impact local communities through a legal basis. Specifically for the Clean Air Act, the EPA has removed the scientific and legal basis that had required the EPA to regulate greenhouse gases under the Clean Air Act. This has a major impact on consumer vehicles, transportation, power plants, and the broader federal sustainability standards, with a shift in the EPA standards. The shift in regulations also causes concerns about the costs of fuel consumption and the subsequent risks that follow. 

Despite the myriad of impacts on local communities, future generations, and the future of climate change can also be affected. Concerns rise regarding the encouragement of a continued increase in fossil fuel dependence and higher consumption, which in turn causes greater greenhouse gas emissions. These are associated with impacts on local communities, such as more severe heat, drought, floods, and wildfire risks. Economic spillovers also lead to infrastructure repair costs, housing instability, and a loss of accurate emissions reporting.

‍IV. Policy Problem

The endangerment finding reversal poses a risk that existing emission reduction efforts will be weakened. One of the most significant U.S environmental regulations is the Clean Air Act, which gives the federal government the authority to regulate air pollutants. The scope of this act was expanded following the Supreme Court case Massachusetts vs. EPA, in which greenhouse gases were ruled to be recognized as pollutants under the Act. This decision allowed the Environmental Protection Agency (EPA) to regulate emissions stemming from vehicles and power plants. 

Building upon this, the EPA issued the “endangerment finding,” which further determined that greenhouse gas emissions pose health risks to people and public welfare. Under Section 202(a) of the Clean Air Act, this finding provided the legal basis for monitoring greenhouse gas emissions from vehicles. Federal emissions rules have historically encouraged automobile manufacturers to invest in electric vehicle technology (EVT) to further reduce vehicle emissions. These regulations have served as the main factors pushing the automotive industry towards cleaner alternatives. Furthermore, this creates much uncertainty for industries that operate across state lines, especially in sectors like transportation and energy. Prior to the reversal, federal emissions standards provided industries with clear expectations and timelines for reducing emissions. Without these directives, manufacturers may face fewer incentives to transition to low-emission vehicles, which subsequently slows down the progress of one of the largest sources of greenhouse gas emissions in the U.S. 

Furthermore, federal vehicle greenhouse gas standards, most commonly referred to as tailpipe emission standards, have played a significant role throughout the years in limiting emissions from light, medium, and heavy-duty vehicles. The EPA has used its authority under the Clean Air Act to enforce these requirements and require emission reporting. The rollback of these standards would eliminate accountability in the automobile industry, and further reduce compliance requirements for manufacturers, potentially higher vehicle emission rates. Likewise, technology transition rules that support the adoption of cleaner energy, when faced with less federal oversight, industries may likely delay adopting cleaner technologies. 

In addition to the vehicle sector, the endangerment finding also allows federal regulation of greenhouse gas emissions from power plants, another major source of emissions in the U.S. The EPA has used its authority under the Clean Air Act to set limits on carbon emissions from fossil fuel-based power generation, and it encourages transitions towards cleaner energy sources. The reversal of the endangerment finding would remove the EPA’s legal authority to regulate greenhouse gas emissions, creating a complicated gap in addressing climate change.    

V. Policy Options

To counteract the effects of the reversal, a multiscale policy response operating across subnational, federal, and societal levels is required. At the state level, governments can assume a compensatory regulatory role by consolidating and expanding their climate governance frameworks. This includes strengthening greenhouse gas emissions regulations, extending vehicle emissions standards modelled on California’s more stringent regime, and institutionalizing carbon pricing mechanisms such as cap-and-trade systems or carbon taxes. In parallel, states can deepen renewable energy mandates and enforce clean electricity standards, thereby embedding decarbonization targets within binding regulatory structures and partially offsetting federal retrenchment.

At the federal level, congressional intervention is necessary to reconstitute the legal and institutional foundations of climate governance. Legislative action could reaffirm the classification of greenhouse gases as pollutants under federal law, thereby restoring regulatory clarity and authority. Beyond reaffirmation, Congress can expand federal jurisdiction over emissions by establishing comprehensive regulatory frameworks, including national vehicle emissions standards and clean transportation policies. The expansion of fiscal instruments, such as clean energy subsidies, tax incentives, and mandatory climate-related disclosure requirements, would further align market behaviour with decarbonization objectives while enhancing transparency and accountability across sectors.

Complementing these formal policy mechanisms, grassroots and market-based initiatives function as critical sites of pressure and adaptation within the broader governance landscape. Civil society organizations and environmental advocacy networks can mobilize public discourse, reshape normative expectations, and exert political pressure for more robust climate action. At the municipal scale, local governments can operationalize climate commitments through targeted action plans and context-specific emissions reduction strategies. Simultaneously, corporate actors and financial institutions can drive decarbonization through voluntary emissions targets, ESG integration, and investment strategies that reallocate capital away from carbon-intensive activities. Taken together, these interlocking approaches illustrate how climate governance can be reconstituted through dispersed but mutually reinforcing forms of authority in the face of federal policy rollback.

VI. Conclusion

As discussed, the rescinding of the 2009 EPA Endangerment Finding will have lasting impacts on the country as a whole. Much of the responsibility will fall on states to increase renewable energy mandates and clean electricity standards, strengthen their own greenhouse gas emissions regulations, expand state vehicle emissions standards, and more. There is also the potential for new legislation to reaffirm greenhouse gases as pollutants under federal law, setting national vehicle emissions standards, and enforcing reporting of emissions. Lastly, there is the potential for civil society and environmental organizations to step in and push for stronger policy and change. The long-term repercussions of the rescission remain to be seen. 

VII. Acknowledgment

The Institute for Youth in Policy wishes to acknowledge Rylan Wang for editing this policy brief.

VIII. Bibliography

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“The Legal Reasoning behind the Endangerment Rescission.” The Salata Institute, 17 Feb. 2026, https://salatainstitute.harvard.edu/the-legal-reasoning-behind-the-endangerment-rescission/.

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