On August 1, 2025, the United States Environmental Protection Agency (“EPA”), under the Trump administration, announced its proposed rule to repeal the 2009 Endangerment Finding issued under the Obama administration. This proposal comes after the EPA announced its decision to reconsider the Endangerment Finding back in March 12, 2025 and stems from a broader deregulatory approach launched by President Trump’s Executive Order “Unleashing American Energy.” This Order directs the EPA to reconsider the Endangerment Finding’s legality and applicability in light of concerns about regulatory burdens on energy affordability, job creation, and national security.
In 2009, the EPA Endangerment Finding found that greenhouse gas emissions endangered both public health and public welfare of current and future generations. The EPA had interpreted the Clean Air Act (“CAA”) Section 202(a) to authorize regulation of new motor vehicle and engine emissions within the United States due to climate change concerns.
The proposed rule also seeks to repeal all greenhouse gas emission standards for light-duty, medium-duty, and heavy-duty vehicles for model years 2012 to 2027 and beyond. If the rule is finalized, motor vehicle and engine manufacturers will no longer have the responsibility for the measurement, control, or reporting of greenhouse gas emissions for vehicles or engines.
The EPA is arguing that the 2009 finding lacks scientific justification and that the EPA has no statutory authority to regulate greenhouse gas emissions under the CAA based on climate change concerns. The EPA argues that the term “air pollution” should be interpreted narrowly to only cover pollutants that cause harm through local or regional exposure. Legal arguments have noted, however, that the EPA’s argument is inconsistent with Massachusetts v. EPA, where the court found that air pollutants contributing to global warming still fall within the CAA’s definition of “air pollutants.” Further, the EPA notes that recent Supreme Court decisions such as Loper Bright Enterprises v. Raimando, West Virginia v. EPA, Utility Air Regulatory Group v. EPA, and Michigan v. EPA provided new guidance on how the EPA should interpret and apply the statutory law.
The Trump administration asserts that rescinding the Endangerment Finding will restore regulatory certainty for automakers and consumers and end over one trillion dollars in hidden taxes.
However, opposers of the proposed rule highlight concerns of rolling back the Endangerment Finding. One concern is that the repeal will weaken efforts to fight climate change and protect human health. Opposers worry about continuing climate disasters with intensifying flooding, wildfires, heat, and hurricanes. Moreover, if this proposed rule is approved, it will prevent the EPA from regulating greenhouse gas emissions that endanger human health and welfare.
The public comment period for this proposed rule closed on September 22, 2025. Public hearings were held mid-August. The proposed rule can be viewed here: Reconsideration of 2009 Endangerment Finding and Greenhouse Gas Vehicle Standards.
Molly Donnell is a J.D. Candidate at Indiana University Robert H. McKinney School of Law. She holds a Master's Degree in Environmental Law & Policy from Vermont Law and Graduate School and a Bachelor's Degree in Environmental Sustainability from Indiana University - Bloomington.
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