EPA Proposes Repeal of 2009 Endangerment Finding on Greenhouse Gases

On July 29, 2025, the U.S. Environmental Protection Agency (EPA), under Administrator Lee Zeldin, announced a proposal to rescind the 2009 "endangerment finding," a pivotal determination that classified greenhouse gases (GHGs) as threats to public health and welfare. This finding has been the cornerstone for regulating emissions from vehicles, power plants, and other industrial sources under the Clean Air Act. The proposed repeal aims to eliminate these regulations, with the EPA estimating annual savings of $54 billion.

The 2009 endangerment finding identified six key GHGs—carbon dioxide, methane, nitrous oxide, hydrofluorocarbons, perfluorocarbons, and sulfur hexafluoride—as pollutants that endanger public health and welfare. This determination provided the legal foundation for the EPA to regulate GHG emissions under the Clean Air Act, following the Supreme Court's 2007 decision in Massachusetts v. EPA, which affirmed the agency's authority to do so.

Administrator Zeldin announced the proposal at an auto dealership in Indianapolis, Indiana, emphasizing the administration's commitment to deregulation and economic growth. He stated that the repeal would eliminate over $1 trillion in regulations, including the previous administration's electric vehicle mandate. Zeldin justified the proposal by referencing a 2024 Supreme Court ruling that limited federal agencies' ability to interpret laws without explicit congressional authorization, asserting that only Congress can now authorize the EPA to regulate carbon dioxide, methane, and similar gases.

The proposal has elicited strong reactions from various stakeholders. Environmental groups and legal experts argue that rescinding the endangerment finding undermines efforts to combat climate change and contradicts established science. They warn that the move could face legal challenges, as the endangerment finding was upheld by the 2007 Supreme Court ruling. Industry groups have expressed mixed reactions; while some support the rollback, others express concern about the potential for increased legal uncertainty and the impact on investments already made in emissions reductions. Automakers and utilities, in particular, highlight the risks of losing regulatory stability. Public health advocates are concerned that eliminating GHG regulations could lead to increased pollution, adversely affecting public health, especially in vulnerable communities.

Lee Zeldin was sworn in as the 17th Administrator of the EPA on January 29, 2025. Prior to this role, he served as a U.S. Representative for New York's 1st Congressional District from 2015 to 2023 and as a New York State Senator from 2011 to 2014. Zeldin has a military background, having served 22 years in the U.S. Army, including a deployment to Iraq in 2006. He retired as a Lieutenant Colonel in the Army Reserve in May 2025.

The proposed repeal is expected to face legal challenges, given the Supreme Court's previous affirmation of the EPA's authority to regulate GHGs. Economically, while the EPA projects significant cost savings, critics argue that the long-term costs of unregulated emissions—such as health impacts and climate-related disasters—could outweigh these savings.

This is not the first time the EPA has sought to roll back environmental regulations. However, rescinding the endangerment finding is unprecedented in its scope, as it would remove the foundational legal basis for regulating GHGs under the Clean Air Act. Previous rollbacks have targeted specific regulations, but this proposal aims to eliminate the authority to regulate GHGs altogether.

The administration has prioritized deregulation to promote economic growth and reduce compliance costs for businesses. Rescinding the endangerment finding aligns with this agenda by removing regulatory burdens associated with GHG emissions. Additionally, the administration has expressed skepticism about the severity of climate change, which may influence its approach to environmental policy.

The EPA's proposal to rescind the 2009 endangerment finding represents a significant shift in U.S. environmental policy, with far-reaching legal, economic, and societal implications. As the proposal undergoes public comment and potential legal scrutiny, its ultimate impact on climate regulation and public health remains to be seen.