EPA Repeals Vehicle Greenhouse Gas Standards and the Underlying Endangerment Finding

At a White House event with President Donald Trump on February 12, 2026, U.S. Environmental Protection Agency (EPA) Administrator Lee Zeldin announced the repeal of EPA's 2009 Greenhouse Gas (GHG) Endangerment Finding, and the repeal of all federal GHG emission standards for light-duty, medium-duty and heavy-duty vehicles and engines. As Administrator Zeldin put it, "The Trump EPA has finalized the single largest act of deregulation in the history of the United States of America," citing $1.3 trillion in saved costs.

2009 Endangerment Finding

The Endangerment Finding was the Obama Administration's 2009 determination that six "well-mixed" GHGs – carbon dioxide, methane, nitrous oxide, hydrofluorocarbons, perfluorocarbons and sulfur hexafluoride – "endanger the public health and welfare of current and future generations." Additionally, EPA found that GHG emissions from new motor vehicles and engines "contribute to the total greenhouse gas air pollution, and thus to the climate change problem, which is reasonably anticipated to endanger public health and welfare."

The Endangerment Finding was issued under Clean Air Act (CAA) Section 202(a)(1), which requires EPA to regulate:

…the emission of any air pollutant from any class or classes of new motor vehicles or new motor vehicle engines, which in his judgment cause, or contribute to, air pollution which may reasonably be anticipated to endanger public health or welfare.

At the time, EPA framed the Endangerment Finding as being "in response to the U.S. Supreme Court's decision in Massachusetts v. EPA," the landmark 2007 case holding that GHGs can be "air pollutants" under the CAA. (See Holland & Knight's previous alert on the Trump Administration's 2025 proposal to repeal it, "Up in the Air: EPA Opens Comment on Repealing Endangerment Finding, Motor Vehicle GHG Rules," August 7, 2025.)

In 2010, as a direct consequence of the Endangerment Finding, EPA established the first GHG emission standards for new motor vehicles and enacted the Tailoring Rule, which extended certain stationary source permitting requirements to GHG emissions. In the years since, EPA has extended GHG regulation to other sectors under the CAA.

Final Repeal Rule Emphasizes Legal Arguments

EPA has now rescinded the 2009 Endangerment Finding and all GHG vehicle and engine standards that rested upon it, concluding that the agency lacked clear congressional authorization to issue the finding.

EPA's final action relies on legal rationales, rescinding the Endangerment Finding based on statutory interpretation arguments and citations to major Supreme Court decisions that have "significantly clarified the law" since 2009. EPA concludes that the Endangerment Finding exceeded EPA's statutory authority under Section 202(a)(1) of the CAA for three core reasons:

• The term "air pollution" in 202(a)(1) is "best" read as pollution that threatens health and welfare through regional exposure, not via global climate effects.
• EPA lacked "procedural discretion" to issue a standalone finding that triggers a duty to regulate without also analyzing those follow-on regulations and issuing them simultaneously while considering costs.
• Section 202(a)(1) does not authorize EPA to analytically sever the finding of an endangerment from the cause-or-contribute finding. The regulated emissions must cause or contribute to the identified harm, without relying on aggregate global emissions outside of the CAA's reach.

Applying the major questions doctrine, EPA further concludes that the federal policy response to global climate change is a question of "vast economic and political significance" that the U.S. Congress did not clearly authorize EPA to resolve in Section 202(a)(1). The preamble grounds this analysis in two seminal major questions doctrine cases involving regulation of GHGs under the CAA, West Virginia v. EPA (the Clean Power Plan) and Utility Air Regulatory Group v. EPA (the Tailoring Rule). The preamble also prominently cites Loper Bright Enterprises v. Raimondo (overruling Chevron deference) and Michigan v. EPA as decisions that have called into question other legal premises underlying the 2009 Endangerment Finding.

Although the August 2025 proposal included an alternative rationale based on critiques of the scientific record underlying the Endangerment Finding, EPA declined to base the final rule on that approach. EPA explained that because it lacks authority to regulate in response to global climate change under Section 202(a)(1), "it would be unnecessary and inappropriate to resolve [scientific] questions in this regulatory context." Accordingly, although the preamble notes that "Administrator [Zeldin] continues to harbor concerns regarding the scientific determinations underlying the Endangerment Finding," EPA stated that it was not finalizing any new findings on the basis of the underlying science. 

Ramifications

If upheld, parties are likely to raise arguments that EPA's repeal of the Endangerment Finding has ramifications beyond motor vehicle GHG standards. EPA asserts that after the Endangerment Finding, the Agency had "sought to expand the same analytical framework to regulatory provisions governing existing vehicles, stationary sources, aircraft, and oil and gas operations." EPA's proposal declines, however, to provide views on whether (or how) other CAA regulatory schemes may be affected, instead merely reiterating its statement from the proposal that it would address related actions "as appropriate" in separate rulemaking proceedings.

Beyond federal policy, the repeal may also have implications for California's vehicle emission program. The preamble states that CAA Section 209(a) preemption of state vehicle emission standards "continues to apply by its own force" regardless of whether EPA prescribes federal GHG standards. Under this view, California and other states would remain preempted from adopting or enforcing their own standards without an EPA waiver. EPA also references Congress' recent disapproval of California GHG waivers under the Congressional Review Act. (For more information on those resolutions, see Holland & Knight's previous alert, "Up in the Air: Congress Nullifies Clean Air Act Waivers for California," May 23, 2025.)

EPA's action is certain to be challenged in court, with the initial stages of litigation playing out in the U.S. Court of Appeals for the District of Columbia Circuit. Given the stakes, however, the ultimate destination is likely the Supreme Court. The composition of the Court has changed significantly, as has the analytical framework for review of federal agency rulemakings.

Holland & Knight Can Help

Holland & Knight's extensive experience with complex regulatory transitions helps clients proactively develop strategies that safeguard their interests throughout this evolving regulatory landscape. For more information or questions, please contact the authors.

Information contained in this alert is for the general education and knowledge of our readers. It is not designed to be, and should not be used as, the sole source of information when analyzing and resolving a legal problem, and it should not be substituted for legal advice, which relies on a specific factual analysis. Moreover, the laws of each jurisdiction are different and are constantly changing. This information is not intended to create, and receipt of it does not constitute, an attorney-client relationship. If you have specific questions regarding a particular fact situation, we urge you to consult the authors of this publication, your Holland & Knight representative or other competent legal counsel.