US EPA proposes to rescind GHG Endangerment Finding
25 July 2025 | updated 30 July 2025
On July 29th, the US Environmental Protection Agency (EPA) released a proposed rule to rescind the GHG Endangerment Finding—a landmark 2009 determination that greenhouse gases—carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), and sulfur hexafluoride (SF6)—in the atmosphere are a threat to the public health and welfare.
In this action, the EPA is proposing to repeal all greenhouse gas emission standards for light-duty, medium-duty, and heavy-duty vehicles and engines. In the proposed rule, the EPA states:
- “We propose that Clean Air Act section 202(a) does not authorize the EPA to prescribe emission standards to address global climate change concerns and, on that basis, propose to rescind the Administrator’s prior findings in 2009 that GHG emissions from new motor vehicles and engines contribute to air pollution which may endanger public health or welfare.”
- “We further propose, in the alternative, to rescind the Administrator’s prior findings in 2009 because the EPA unreasonably analyzed the scientific record and because developments cast significant doubt on the reliability of the findings.”
- “Lastly, we propose to repeal all GHG emission standards on the alternative bases that no requisite technology for vehicle and engine emission control can address the global climate change concerns identified in the findings without risking greater harms to public health and welfare.”
The EPA proposal also cites updated scientific data that challenge the assumptions behind the 2009 Endangerment Finding. Cited data includes the updated studies and information in the Department of Energy’s 2025 Climate Work Group study that has been concurrently released for public comment.
The Endangerment Finding followed the 2007 Supreme Court ruling that carbon dioxide is a pollutant and that the EPA has the authority to regulate CO2 emissions. The finding provides the legal basis for EPA GHG emission regulations—from GHG emission standards for light- and heavy-duty vehicles to powerplant emission regulations. A repeal of the finding would prevent the agency from having any climate regulations on the books.
The EPA first indicated it would reconsider the GHG Endangerment Finding in March, in the announcement about the ‘historic’ rollback of air emissions regulations. On July 23rd, EPA Administrator Lee Zeldin told the Newsmax news channel that the agency has sent to the Office of Management and Budget a proposed rule to repeal the Endangerment Finding. During his confirmation hearing, EPA Administrator Lee Zeldin declined to say whether he believed the EPA had a responsibility to regulate climate change.
The EPA will initiate a public comment period on the proposed rule. If finalized, the repeal of the Endangerment Finding would in all likelihood face legal challenges.
Source: US EPA