Pittsburgh, PA and Washington, DC
Environmental Alert
(by Gina Buchman, Gary Steinbauer, Christina Puhnaty and Alex Graf)
On February 12, 2026, the U.S. EPA announced a rule finalizing EPA’s repeal of the Obama administration’s 2009 Endangerment Finding as well as all federal greenhouse gas emissions standards for vehicles and engines of model years 2012 and beyond (Final Rule). Administrator Zeldin originally announced the agency’s intent to do so in March of 2025 as part of the agency’s “31 Historic Actions to Power the Great American Comeback” announcement, and a proposed rule was issued in August of 2025. See 90 Fed. Reg. 36288 (Aug. 1, 2025). The Final Rule has not yet been published in the Federal Register, but a pre-publication version of the Final Rule is available on EPA’s website.
The “endangerment finding” refers to the finding EPA made in 2009 prior to setting emissions standards for new motor vehicles and engines pursuant to Section 202(a)(1) of the Clean Air Act, 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 . . . cause, or contribute to, air pollution which may reasonably be anticipated to endanger public health or welfare.” In 2009, EPA concluded that “the current and projected concentrations of the six key well-mixed greenhouse gases—carbon dioxide, methane, nitrous oxide, hydrofluorocarbons, perfluorocarbons, and sulfur hexafluoride—in the atmosphere threaten the public health and welfare of current and future generations.” 74 Fed. Reg. 66496 (Dec. 15, 2009). EPA further concluded that the combined emissions of these well-mixed greenhouse gases from new motor vehicles and new motor vehicle engines contribute to the greenhouse gas pollution that threatens public health and welfare. The 2009 Endangerment Finding was upheld by the U.S. Court of Appeals for the District of Columbia Circuit in 2012. See Coalition for Responsible Regulation v. EPA, 684 F.3d 102 (D.C. Cir. 2012), rev’d on other grounds Utility Air Regulatory Grp. v. EPA, 134 S. Ct. 2427 (2014).
Trump EPA’s Repeal
The Trump administration is now repealing the 2009 Endangerment Finding and subsequently promulgated vehicle and engine standards. The repeal relies on several Supreme Court decisions that EPA states “significantly clarified the scope of EPA’s authority under the [Clean Air Act] and made clear that the interpretive moves the Endangerment Finding used to launch an unprecedented course of regulation were unlawful,” including Loper Bright Enterprises v. Raimondo, 603 U.S. 369 (2024) (overturning Chevron deference), West Virginia v. EPA, 597 U.S. 697 (2022) (invoking the major questions doctrine), Michigan v. EPA, 576 U.S. 743 (2015) (requiring cost considerations in statutory interpretation), and Utility Air Regulatory Group v. EPA, 573 U.S. 302 (2014) (rejecting the application of greenhouse gas emissions standards to Title I and Title V stationary sources). EPA’s Final Rule repeals the 2009 Endangerment Finding on two primary bases:
- Section 202(a) does not provide statutory authority for EPA to prescribe emission standards for the purpose of addressing global climate change.
- There is no requisite control technology for light-, medium-, or heavy-duty vehicles and engines that would meaningfully address the potential public health or welfare impacts of related greenhouse gas emissions. Even if the United States were to eliminate all greenhouse gas emissions from all vehicles, there would be no material impact on global climate indicators through 2100.
According to EPA, both conclusions independently give rise to the agency having exceeded its authority with the 2009 Endangerment Finding and the resulting regulations. Additional conclusions advanced by EPA in the Final Rule include:
- Section 202(a)(1) requires EPA to find that the specific air pollutant emissions from the class of new motor vehicles or engines at issue cause, or contribute to, the same air pollution that EPA finds endangers public health or welfare, without relying on international emissions. Under this interpretation, EPA concludes that the agency is precluded from issuing standalone endangerment and contribution findings.
- The policy response of the United States to global climate change concerns is a question for Congress, and Congress did not decide this policy response when promulgating Section 202(a)(1).
- EPA’s 2009 Endangerment Finding relied on a “profound misreading” of the Supreme Court’s Massachusetts v. EPA, which decision held that greenhouse gases are “air pollutants” under Section 302(g), but “did not require EPA to make an endangerment finding and did not address the logic or conclusions on which EPA would later base its 2009 Endangerment Finding.”
Immediate Impact: Vehicle and Engine Standards
Relying on the 2009 Endangerment Finding, beginning in 2010, EPA promulgated numerous vehicle and engine standards applicable to those vehicles and engines manufactured or imported into the United States, which created obligations for manufacturers to measure, control, and report greenhouse gas emissions for engines and vehicles. This includes the light-duty vehicle greenhouse gas standards for model years (MY) 2012-2016, MY 2017 and later, MY 2021-2026, and MY 2027 and later multi-pollutant standards. For medium- and heavy-duty vehicle and engine greenhouse gas standards, this includes the Phase 1, Phase 2, and Phase 3 standards.
Along with repealing the 2009 Endangerment Finding, the Final Rule also repeals all the aforementioned light-, medium-, and heavy-duty engine and vehicle greenhouse gas emission standards. Absent the 2009 Endangerment Finding, EPA stated that it lacks statutory authority to prescribe standards for greenhouse gas emissions under Section 202(a)(1). As a result, engine and vehicle manufacturers will no longer have an obligation to measure, control, and report greenhouse gas emissions, including for MYs manufactured prior to the effective date of the Final Rule.
The Final Rule also removes certification requirements and associated test procedures related to greenhouse gas emissions, as well as the averaging, banking, and trading provisions for the emissions credit program specific to greenhouse gas emissions. Mobile source regulations unaffected by the final rule are mobile source air toxics standards and vehicle fuel economy standards and labeling requirements (CAFE). The CAFE standards are administered by the National Highway Traffic Safety Administration (NHTSA) under separate statutory authority.
Long-Term Impact: Greenhouse Gas Regulation
EPA’s repeal of the 2009 Endangerment Finding does not affect existing stationary source greenhouse gas regulations but may call into question the underlying determinations made by EPA to regulate greenhouse gas emissions in those standards. EPA notes in the Final Rule preamble that the consequences of the agency’s former broad interpretation of its authority under Section 202(a) in the 2009 Endangerment Finding were not limited to mobile sources and that the agency has applied the 2009 Endangerment Finding’s analytical framework to various other rulemakings, including provisions governing existing vehicles, stationary sources, aircraft, and oil and gas operations. Although EPA does not regulate stationary sources pursuant to Section 202(a)(1) of the Clean Air Act, Section 111 similarly requires EPA to regulate emissions from stationary sources in source categories that “cause[], or contribute[] significantly to, air pollution which may reasonably be anticipated to endanger public health or welfare.” Accordingly, in many post-2009 rulemakings, EPA has relied, at least in part, on the 2009 Endangerment Finding as a basis to regulate greenhouse gas emissions from stationary sources.
For example, in promulgating its 2016 40 C.F.R. Part 60, Subpart OOOOa rulemaking, EPA relied in part on the 2009 Endangerment Finding to establish a rational basis for establishing regulations to control methane, a greenhouse gas, from the oil and natural gas source category. See 81 Fed. Reg. 35824, 35833–37, 35877 (June 3, 2016). EPA’s position in 2016—which EPA reaffirmed in its 2024 methane rule promulgating Subpart OOOOb—was that it needed to only have a rational basis for determining which pollutants to regulate under Section 111(b)(1) and that it was not required to make pollutant-specific significant contribution findings when promulgating such standards. 81 Fed. Reg. at 35828; 89 Fed. Reg. 16820, 16854 (Mar. 8, 2024). Despite EPA’s partial reliance on the 2009 Endangerment Finding to establish this rational basis with respect to methane, the Final Rule does not immediately impact EPA’s OOOO/a/b/c rulemakings.
Expected Legal Challenges and Resulting Legal Uncertainty
States, environmental groups, and others have vowed to swiftly challenge EPA’s repeal. The expected legal challenges, which cannot be filed until EPA publishes the Final Rule in the Federal Register, could take years to run their course and may unfold over the remaining three years of this administration and perhaps longer. Federal courts, including the U.S. Supreme Court, may ultimately decide the fate of the Final Rule.
Furthermore, it is unclear whether the repeal will leave litigants involved in so-called climate change tort cases without CAA preemption defenses. States, entities, and individuals have brought tort actions against energy and other companies asserting common law claims for alleged climate change harms. Companies defending themselves in these actions often argue that such common law tort claims are preempted under the CAA. Although EPA states in the Response to Comments it issued with the Final Rule that the repeal of the 2009 Endangerment Finding that it believes that federal common laws claims are still preempted under the CAA, it is silent on state common law claims. Whether EPA’s repeal of the Endangerment Finding limits available defenses in these climate change tort actions likely will be decided in the courts.
Babst Calland’s Environmental practice attorneys are closely tracking these developments and are available to provide guidance on how these actions affect your business. For more information, please contact Gina Buchman at (202) 853-3483 or gbuchman@babstcalland.com, Gary Steinbauer at (412) 394-6590 or gsteinbauer@babstcalland.com, Christina Puhnaty at (412) 394-6514 or cpuhnaty@babstcalland.com, or Alexandra Graf at (412) 394-6438 or agraf@babstcalland.com.
