The 2009 Endangerment Finding is EPA’s scientific-legal determination that the combined atmospheric concentrations of six greenhouse gases (CO2, CH4, N2O, HFCs, PFCs, SF6) threaten public health and welfare, and that emissions from new motor vehicles contribute to that threat. Under Clean Air Act §202(a) it served as the statutory prerequisite allowing EPA to treat those gases as “air pollutants” and to issue greenhouse‑gas standards (for vehicles and, by extension, other GHG regulations) under the Act.
EPA may regulate greenhouse gases using existing Clean Air Act provisions when the statute’s triggers and criteria apply (for example, §202(a) requires regulation of new motor‑vehicle emissions if EPA finds GHGs endanger health/welfare). But for large, novel economy‑wide regulatory programs courts (notably in West Virginia v. EPA) require clear congressional authorization — meaning some broad or “major” climate measures effectively require Congress to act.
Lee Zeldin is the politically appointed Administrator of the EPA (sworn in January 29, 2025). As Administrator he leads the agency and signed/directed the agency action to rescind the 2009 Endangerment Finding, making the rescission the agency’s official regulatory action.
Key federal actions that have relied on the 2009 Endangerment Finding include EPA tailpipe/vehicle GHG standards (light‑, medium‑ and heavy‑duty vehicle standards), EPA permitting decisions that treat GHGs as regulated NSR pollutants (the "Tailoring"/PSD program), and multiple NSPS or sector rules (power‑plant and oil & gas GHG or methane rules). The Endangerment Finding underpinned the Clean Power Plan-era efforts and later vehicle and stationary‑source GHG rules.
The White House/EPA savings figures are agency/administration estimates based on removing future compliance costs those agencies and industry would incur under existing/forthcoming GHG rules; the administration’s materials cite aggregated projected regulatory costs saved ("over $1.3 trillion" total and about $2,400 per new vehicle) but they have not published a peer‑reviewed damage‑or‑cost analysis in the public docket showing independent verification. Independent analysts have questioned such headline savings because they omit health, climate, and co‑pollutant benefits and depend on assumptions about which rules would survive legal challenge or be replaced.
Yes. Rescinding the Endangerment Finding is likely to prompt lawsuits from states, environmental groups, and some cities that defended the 2009 finding previously; those plaintiffs (and likely multistate coalitions and national environmental NGOs) would challenge the rulemaking procedure, the scientific record, and arbitrary or capricious reasoning under the Administrative Procedure Act. Industry groups and some states that support rescission could intervene to defend it.
Rescinding the Endangerment Finding would remove the Clean Air Act’s principal legal basis for many EPA GHG regulations (notably vehicle and some stationary‑source standards), which would likely slow or roll back federal GHG regulatory action and reduce near‑term federal controls on U.S. emissions. That would make meeting U.S. international climate commitments (e.g., NDC targets under the UNFCCC/Paris framework) harder absent new legislation or state/market actions; concrete emissions impacts depend on what rules are actually withdrawn, replaced by other policies, or upheld in court.