EPA Proposes Repeal of 2009 Endangerment Finding on Greenhouse Gases

On July 29, 2025, the Environmental Protection Agency (EPA), under Administrator Lee Zeldin, announced a proposal to repeal the 2009 "endangerment finding," a pivotal determination that identified greenhouse gases as a threat to public health and welfare. This move aims to dismantle regulations affecting vehicles, power plants, and other pollution sources, marking a significant shift in U.S. environmental policy.

The proposed repeal of the endangerment finding, which has been the legal foundation for regulating greenhouse gas emissions under the Clean Air Act, represents the most substantial deregulatory action in U.S. history, according to Zeldin. While the administration argues that this action will eliminate economically harmful regulations, environmental groups and former EPA leaders warn that it could dismantle decades of climate protections and face substantial legal challenges.

Background

The 2009 endangerment finding was established during the Obama administration, classifying greenhouse gases as pollutants that threaten public health and welfare. This finding provided the legal basis for regulating emissions under the Clean Air Act and was based on the 2007 Supreme Court decision in Massachusetts v. EPA, which affirmed the agency's authority to regulate greenhouse gases.

Details of the Announcement

The proposal includes rescinding federal tailpipe emission standards, effectively removing the legal basis for regulating greenhouse gases across multiple U.S. industries. Zeldin cited a 2024 Supreme Court ruling that curtailed federal agencies' ability to interpret laws—revising the Chevron deference standard—as justification for the repeal. He emphasized that only Congress can now authorize the EPA to regulate carbon dioxide, methane, and similar gases. The announcement was made at a truck factory in Indiana, with Energy Secretary Chris Wright in attendance.

Reactions and Implications

Environmental groups and former EPA leaders have criticized the move, warning it could dismantle decades of climate protections and face substantial legal challenges. Critics argue that the rollback disregards the worsening impacts of climate change and may face insurmountable legal challenges due to the 2007 Supreme Court ruling affirming EPA authority to regulate greenhouse gases. Legal experts caution that such sweeping changes require adherence to the Administrative Procedure Act, which mandates a public comment period and evidence-based justification for regulatory revisions. Reversing the 2009 finding would necessitate disproving well-established scientific consensus, which is unlikely to succeed legally.

Administrator Lee Zeldin's Background

Lee Michael Zeldin, born January 30, 1980, is an American attorney, politician, and former Army intelligence officer. He has been serving as the 17th Administrator of the Environmental Protection Agency since January 29, 2025. A member of the Republican Party, he represented New York's 1st congressional district in the United States House of Representatives from 2015 to 2023. During his tenure at the EPA, Zeldin has reframed the purpose of the agency and pushed for substantial environmental deregulation.

Historical Context and Precedents

The 2009 endangerment finding was a cornerstone of U.S. climate policy, enabling the regulation of greenhouse gas emissions under the Clean Air Act. Similar efforts in the past have faced legal challenges, and this move is expected to be no different.

Conclusion

The EPA's proposal to repeal the 2009 endangerment finding marks a significant shift in U.S. environmental policy, aligning with the Trump administration's broader deregulatory agenda. While proponents argue that it will eliminate economically harmful regulations, critics warn of severe environmental and public health consequences, as well as substantial legal challenges ahead.