On July 29, 2025, the Environmental Protection Agency released a proposed rule to rescind the 2009 endangerment finding, the determination under Section 202 of the Clean Air Act that greenhouse gas emissions from new motor vehicles contribute to air pollution that may reasonably be anticipated to endanger public health and welfare. The proposal would also repeal all federal greenhouse gas emission standards for light-, medium- and heavy-duty vehicles and engines. It was published in the Federal Register on August 1.
The EPA said the proposed action would save Americans about $54 billion a year under what it described as conservative forecasts, through lower vehicle costs. The agency's proposal would keep in place standards for criteria pollutants and other air toxics from vehicles, as well as fuel economy testing and labeling requirements.
What the endangerment finding is
The endangerment finding was issued in December 2009, following the Supreme Court's 2007 decision in Massachusetts v. EPA, which held that greenhouse gases are air pollutants under the Clean Air Act and that the EPA must decide whether they endanger public health or welfare. Once the EPA made that finding for vehicle emissions, it became legally required to regulate those emissions, which led to the first federal greenhouse gas standards for cars and trucks, starting with model year 2012.
The finding has served as the legal foundation for greenhouse gas regulation of vehicles. It also underpins, by analogy and through related findings under other sections of the Clean Air Act, regulation of greenhouse gases from power plants and oil and gas operations, though those rules rest on separate statutory provisions and determinations.
The legal argument
The EPA's proposal advances legal and scientific arguments. On the legal side, the agency argues that Section 202 is best read as addressing air pollution that harms health through local or regional exposure, rather than global climate change, and that the Supreme Court's major questions doctrine, articulated in West Virginia v. EPA in 2022, requires clear congressional authorization for regulations with vast economic and political significance. The agency also argues that vehicle greenhouse gas standards have little measurable effect on global temperatures.
The proposal also questions aspects of the scientific basis for the original finding, citing a report from a group of researchers commissioned by the Department of Energy. That report has been disputed by many climate scientists, and the scientific dimension of the proposal is expected to be contested in comments and litigation.
What happens next
The proposal is open for public comment, and the agency has scheduled public hearings. After reviewing comments, the EPA would issue a final rule. A final rescission is widely expected to be challenged in federal court by states, environmental groups and possibly some industry participants, and the case could ultimately reach the Supreme Court. Until a final rule takes effect and survives any legal challenge, the existing standards remain in place.
Effects on vehicles and fuel markets
The most direct effect would be on vehicle standards. The current federal greenhouse gas standards for light-duty vehicles for model years 2027 to 2032, finalized in 2024, would push automakers to sell a growing share of electric and hybrid vehicles. Separately, Congress has already eliminated penalties for violating fuel economy standards set by the National Highway Traffic Safety Administration, and the July 2025 budget law ended federal tax credits for new and used electric vehicle purchases after September 30, 2025.
Taken together, these changes reduce regulatory pressure on automakers to shift toward electric vehicles in the US market. For oil markets, the effect would be to slow the expected decline in US gasoline and diesel demand compared with forecasts that assumed the 2024 standards would remain. The size of that effect is uncertain and depends on consumer preferences, battery costs and state policies.
California's ability to set its own vehicle standards, under a waiver granted by the EPA, was revoked by Congress through the Congressional Review Act earlier in 2025. California and other states have challenged that revocation in court.
Effects on power markets
For electricity, the link is less direct. Slower adoption of electric vehicles would reduce the growth of electricity demand from transport, which many utilities had included in their load forecasts. That would offset part of the load growth expected from data centers, manufacturing and building electrification, though the transport share is relatively small in near-term forecasts.
The endangerment finding for vehicles does not directly govern power plant emissions. The EPA has separately proposed repealing greenhouse gas standards for fossil fuel power plants, issued in 2024, using different legal reasoning under Section 111 of the Clean Air Act. If the vehicle finding were rescinded on the grounds that Section 202 does not reach global climate pollution, a similar argument could be applied to other sections, but each rule would require its own rulemaking.
The state dimension
States remain able to pursue their own climate policies within their authority. California, New York, Washington and other states have clean electricity standards, carbon markets or low-carbon fuel standards that operate independently of federal greenhouse gas regulation. Federal rescission would not by itself alter those programs, although litigation over preemption is possible in some areas.
Implications for trade and investment
For automakers, the proposal adds to uncertainty about the long-term regulatory environment, which matters for investment decisions in battery plants and electric vehicle production lines that run over a decade or more. Some manufacturers have already adjusted their electric vehicle plans in response to slower sales growth and policy changes. Others have said they will continue to invest given demand in other markets, including Europe and China, where regulations continue to require rising shares of zero-emission vehicles.
For international climate negotiations, the proposal reinforces the US shift away from federal climate regulation, following the withdrawal from the Paris Agreement announced in January.
What to watch
The comment period, the EPA's response and the timing of a final rule are the next steps. Legal challenges after a final rule will determine whether the rescission stands. In parallel, the EPA's proposed repeal of power plant greenhouse gas standards and its reconsideration of oil and gas methane rules will shape how far federal climate regulation is rolled back across the energy sector.