By Mike Nasi & Travis Wussow

On February 12, 2026, EPA Administrator Lee Zeldin signed a final rule rescinding the 2009 Greenhouse Gas Endangerment Finding and repealing all motor vehicle greenhouse gas emission standards under the Clean Air Act. This is the most consequential Clean Air Act action in over a decade. The action reveals the administration’s legal strategy of focusing on the statutory authority conferred by the Clean Air Act rather than debating climate science and climate modeling. The administration has signaled its intent to use this same approach for GHG regulation across the entire economy, which may reshape the regulatory landscape for power generators, oil and gas producers, manufacturers, and other energy-intensive industries.

What EPA Did

EPA’s final rule rescinds the agency’s 2009 finding that greenhouse gas emissions from motor vehicles endanger public health and welfare, and repeals every GHG emission standard EPA has issued for light-duty, medium-duty, and heavy-duty vehicles since 2010. The rule rests on three independent legal bases:

Statutory Interpretation. EPA concludes that the best reading of Clean Air Act Section 202(a)(1) does not authorize regulation of GHG emissions based on global climate change concerns. The agency reads “air pollution” in Section 202(a)(1) as pollution threatening health and welfare through local or regional exposure – consistent with the statute’s structure, history, and EPA’s own practice before 2009. EPA also concludes that the statute does not grant the Administrator discretion to issue standalone endangerment findings without simultaneously promulgating emission standards.

Major Questions Doctrine. Consistent with the Supreme Court’s decisions in West Virginia v. EPA and UARG v. EPA, the agency concludes that deciding the nation’s policy response to global climate change is a question of “vast economic and political significance” that Congress did not clearly delegate to EPA through Section 202(a)(1).

Futility. EPA finds that even the complete elimination of all GHG emissions from every vehicle in the United States – new and existing, across all weight classes – would reduce global mean surface temperature by only approximately 0.037 degrees Celsius by 2100. EPA argued that variability in temperature measurement from 2016 to 2025 was 0.14 degrees Celsius, nearly four times greater than the modeled impact of eliminating all U.S. vehicle GHG emissions over the next 75 years.

What Changed from the Proposal

EPA’s proposed rule, published in August 2025, included several alternative bases that the agency did not finalize. The most notable change: EPA dropped its proposed challenge to the underlying climate science. The final rule does not make a new scientific finding. Instead, it rests entirely on legal and statutory grounds – that EPA lacks authority to regulate GHGs under Section 202(a)(1), regardless of the science.

EPA also declined to finalize alternative rationales based on requisite technology under Section 202(a)(2) and vehicle affordability and safety concerns, concluding those issues fall outside its authority. The futility rationale, which was proposed as a supporting alternative, was elevated to an independent, standalone basis for repeal in the final rule.

One practical note: EPA retained certain heavy-duty test procedures and compliance elements that NHTSA references for its fuel efficiency program, so those remain in place.

Why It Matters Beyond Vehicles

While this rule directly addresses vehicle emissions, its legal reasoning has implications across every sector subject to GHG regulation under the Clean Air Act:

• Power Sector. EPA proposed to rescind GHG limits for fossil fuel-fired power plants under Sections 111(b) and 111(d) in June 2025. The legal reasoning in this final rule – particularly that GHGs are not “air pollution” under the CAA and that climate policy is a major question for Congress – reinforces that proposal and signals how EPA will approach power sector GHG regulation going forward. The futility argument may be especially significant here: if eliminating all U.S. vehicle GHG emissions – a larger slice of national emissions than the power sector – produces only a de minimis temperature impact, the same logic applies with at least equal force to power plant GHG standards, particularly given how much U.S. power sector emissions have already declined through market-driven fuel switching. And the statutory bar is arguably higher for power plants – Section 111(b)(1)(A) requires that a source category “contribute significantly” to endangering air pollution, a stricter threshold than Section 202(a)(1)’s “contribute.” If vehicle emissions fail the lower standard on futility grounds, power plant emissions face an even steeper climb under Section 111.
• Oil and Gas. The administration’s approach to the endangerment finding may inform future actions on methane regulation under Section 111.
• Broader Regulatory Posture. By concluding that the Clean Air Act does not authorize EPA to set national climate policy, the agency has articulated a legal framework that reaches well beyond the vehicle sector.

This rule does not affect NHTSA’s Corporate Average Fuel Economy (CAFE) standards, fuel economy labeling, or criteria pollutant and air toxics standards under the Clean Air Act.

What’s Next

Litigation is certain. Legal challenges will certainly be filed in the D.C. Circuit within 60 days of Federal Register publication. Connecticut Attorney General William Tong, the president of the National Association of Attorneys General, has committed to challenging the rule. The U.S. Climate Alliance – led by California Governor Gavin Newsom and Wisconsin Governor Tony Evers – has called the repeal “unlawful.” Earthjustice, the American Lung Association, and the American Public Health Association have announced intent to sue. Some automakers and EV manufacturers may join as well.

Key legal questions will include whether EPA properly exercised its authority to rescind a prior finding, whether the statutory interpretation is consistent with Massachusetts v. EPA, and whether the administrative record supports the futility determination.

Congressional action is possible but unlikely. Congress could act to codify or reverse EPA’s decision, but neither outcome appears likely in the current political environment.

State-level activity will increase. States that have adopted California’s vehicle emission standards or enacted their own climate regulations will face new questions about the federal regulatory framework. Expect increased state-level activity as this plays out.

For questions about how EPA’s rescission of the Endangerment Finding affects your operations or regulatory strategy, please contact Mike Nasi or Travis Wussow.

The opinions expressed are those of the authors and do not necessarily reflect the views of the firm, its clients, or any of its or their respective affiliates. This article is for informational purposes only and does not constitute legal advice. For more information, please contact a member of the Environment & Natural Resources practice.

Meet Michael

Michael J. Nasi is the founder and Chair of Jackson Walker’s Carbon Capture, Utilization and Storage (CCUS) group and Chair of the Digital Infrastructure & Data Centers practice. His practice encompasses numerous federal and state environmental and utility regulatory programs, with a focus on environmental and utility regulatory counseling and litigation for the power sector, as well as project development incentives and power market reforms.

Mike has been an expert witness and speaker at hearings, energy policy events, and classrooms across the country, including the White House and the United Nations, and is published in several trade, law, and business journals on environmental and energy law. He participates on advisory boards or as counsel for several state and regional energy research initiatives, including the Wyoming Energy Agency, North Dakota’s Energy & Environmental Research Center (EERC) Foundation Board, the Southern States Energy Board (SSEB), the Energy Council, and the University of Houston Center for Carbon Management in Energy (CCME).

Meet Travis