On February 12, 2026, the U.S. Environmental Protection Agency (EPA) issued a final rule (the Final Rule) rescinding the agency's prior finding in 2009 that greenhouse gases (GHG) from motor vehicles threaten public health and welfare (the 2009 Endangerment Finding). The Final Rule also repealed all GHG emission standards for light-duty, medium-duty, and heavy-duty vehicles and engines, which standards directly relied on the 2009 Endangerment Finding.1
EPA issued the 2009 Endangerment Finding following the U.S. Supreme Court's 2007 decision in Massachusetts v. EPA, which held that carbon dioxide and other GHGs are air pollutants and may therefore be regulated under the Clean Air Act (CAA). The legal challenge in Massachusetts arose under Section 202(a)(1) of the CAA, which requires EPA to issue motor vehicle emission standards for any air pollutants that "cause, or contribute to, air pollution which may reasonably be anticipated to endanger public health or welfare."2 Following that case, EPA issued its Endangerment Finding that six "well-mixed greenhouse gases", including carbon dioxide and methane, threaten public health and welfare by contributing to climate change. Once the 2009 Endangerment Finding was issued, the agency was required to then issue motor vehicle emissions standards for those pollutants.
In rescinding the 2009 Endangerment Finding, EPA concluded that regulating GHG emissions exceeded the agency's statutory authority under the CAA. As legal support for its interpretation, EPA relied in part on the "major questions doctrine" articulated by the U.S. Supreme Court, which provides that agencies seeking to regulate matters of vast economic and political significance must have clear and explicit authorization from Congress to do so.3 EPA said that the 2009 Endangerment Finding improperly expanded the agency's authority beyond "air pollution that endangers public health or welfare through local or regional exposure" (emphasis added), and that issues of a global nature, such as climate change, were outside of the authority Congress granted to EPA in the CAA. EPA also indicated that that it had previously erred by not considering costs in the 2009 Endangerment Finding analysis.
The immediate effect of EPA's repeal of the Endangerment Finding is the invalidation of GHG emission standards for motor vehicles. However, the repeal could have far-reaching implications for other GHG regulations issued under the CAA, since the 2009 Endangerment Finding provided legal support for EPA's other endangerment findings and regulations. EPA has expressly indicated that it intends to rescind its 2016 Aircraft GHG Endangerment Finding under CAA Section 231, and it has also published a proposed rule to repeal New Source Performance Standards for GHG emissions under CAA Section 111.4 Those actions are consistent with EPA's other actions to reduce the regulation of GHGs, including its proposal to essentially terminate the GHG Reporting Program and its extension of deadlines relating to rules affecting methane emissions in the oil and gas sector. The fate of GHG emissions limits in Prevention of Significant Deterioration pre-construction permits and Title V Operating permits is also unclear.
EPA's repeal of the 2009 Endangerment Finding is already being challenged in court. Two sets of plaintiffs (i.e., a youth climate group and a coalition of conservation and public health groups) have filed petitions for review in the United States Court of Appeals for the District of Columbia Circuit, and a number of other non-governmental organizations have signaled their intent to also bring legal challenges. The California Attorney General Rob Bonta and California Governor Gavin Newsom have also indicated that they will sue EPA over the Final Rule. Those cases will likely be appealed all the way to the United States Supreme Court.
The effects of this Final Rule are complex. Companies with operations subject to the vehicle GHG regulations (and any future-impacted GHG regulations) may see relaxed federal GHG standards and more streamlined permitting as a result of the rescission. However, some states may be motivated by the Final Rule to enact or strengthen their own GHG-related requirements in an attempt to address perceived regulatory gaps, which could result in a patchwork of differing rules. Multinational companies also need to navigate vastly-differing GHG standards across jurisdictions. Stakeholders should consider monitoring the related litigation and evaluating with legal counsel the potential effects of the Final Rule on relevant federal, state, and foreign GHG requirements.
The Final Rule was published in the Federal Register on February 18, 2026, and will become effective on April 20.
1 The repeal of federal GHG vehicle standards includes repeal of all associated test procedures, averaging, banking, trading, reporting, and fleet-average emission requirements.
2 42 U.S.C. § 7521(a)(1).
3 See, e.g., W. Virginia v. Env't Prot. Agency, 597 U.S. 697 (2022) (holding that EPA lacked clear congressional authorization under the Clean Air Act to implement greenhouse gas regulations for power plants that would have required shifting electricity generation from higher emitting fossil fuel plants to renewable sources like wind and solar).
4 90 Fed. Reg. 25,752 (June 17, 2025).
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