The U.S. Environmental Protection Agency has finalised a rule rescinding its 2009 “endangerment finding” for greenhouse gases and removing federal greenhouse gas standards for new vehicles and engines. Announced at the White House on 12 February 2026, the administration billed the move as the largest deregulatory action in U.S. history, projecting savings of more than $1.3 trillion and cancelling off‑cycle credits including the start‑stop feature. (epa.gov)
The 2009 finding concluded that six greenhouse gases, including carbon dioxide and methane, endanger public health and welfare under Section 202 of the Clean Air Act. It followed the U.S. Supreme Court’s 2007 ruling in Massachusetts v. EPA, which held that greenhouse gases are “air pollutants” and that the agency must decide, on the science, whether they endanger health or welfare. In 2012, the D.C. Circuit upheld EPA’s endangerment finding and related vehicle rules. (law.cornell.edu)
EPA’s final action eliminates the federal programme of vehicle greenhouse gas measurement, certification and compliance dating back to model year 2012, and retires associated credit schemes. In parallel, the administration has already moved to reset Corporate Average Fuel Economy standards, signalling a broader re‑orientation of federal transport policy away from greenhouse gas regulation. (epa.gov)
The White House argues the repeal will lower manufacturing costs and vehicle prices; press secretary Karoline Leavitt said the change would reduce automaker costs by about $2,400 per vehicle. Those figures are contested by environmental and health groups, which say weaker standards raise fuel costs and pollution; legal challenges are being prepared. (yahoo.com)
State–federal authority is already in contention. In June 2025, President Trump signed three Congressional Review Act resolutions disapproving EPA decisions that granted California waivers for Advanced Clean Cars II, Advanced Clean Trucks and related programmes-curbing the state’s ability to run stricter greenhouse gas rules. Following this week’s repeal, California’s attorney general said the state will sue, arguing the action violates settled law. (whitehouse.gov)
Litigation will centre on the Clean Air Act and recent Supreme Court doctrine. EPA’s preamble cites Loper Bright (which overruled Chevron deference) and West Virginia v. EPA’s “major questions” test to justify a narrower reading of the statute, while opponents point to Massachusetts v. EPA and past appellate rulings upholding the endangerment finding. Petitions for review of nationally applicable EPA rules are filed in the D.C. Circuit within 60 days of Federal Register publication. (supreme.justia.com)
The scientific basis will also be contested. EPA’s 2025 proposal leaned on a Department of Energy “Climate Working Group” report that challenged mainstream climate science. On 30 January 2026, a federal judge held the group was unlawfully formed under the Federal Advisory Committee Act, though the court did not strike the report from the record. That ruling is likely to feature in ensuing cases about the quality of the evidence EPA relied upon. (latimes.com)
For vehicle makers and fleet operators, the immediate federal greenhouse gas compliance regime falls away, but fuel‑economy obligations under NHTSA’s CAFE programme remain and are in the midst of a separate rulemaking. The dual track-no EPA greenhouse gas standards alongside revised CAFE-creates planning uncertainty until courts clarify the scope of EPA’s authority and any stays are decided. (whitehouse.gov)
Beyond transport, the 2009 finding underpinned regulatory approaches that flowed from Massachusetts v. EPA. EPA and several states are already sparring over separate proposals affecting power‑station greenhouse gas rules; those proceedings indicate the administration may seek further sectoral reversals that will rise or fall with the courts’ reading of the Clean Air Act post‑Loper Bright. (oag.ca.gov)
Analysis: The legal question now squarely presented is whether EPA can withdraw its own danger determination and exit greenhouse gas regulation for new motor vehicles without contravening Massachusetts v. EPA’s framework. With Chevron deference gone and “major questions” ascendant, any D.C. Circuit ruling is a credible candidate for Supreme Court review this year. (supreme.justia.com)