On February 12, 2026, the U.S. Environmental Protection Agency (EPA), under Administrator Lee Zeldin and alongside President Trump, finalized a major rule that revokes the 2009 Greenhouse Gas Endangerment Finding, a landmark Obama-era determination that greenhouse gases (GHGs) like carbon dioxide endanger public health and welfare.

This finding had served as the legal foundation for federal regulations on GHG emissions under the Clean Air Act, particularly for motor vehicles, but also influencing broader climate policies.

The 2009 finding concluded that six GHGs (including CO₂, methane, nitrous oxide, etc.) from new motor vehicles and engines contribute to air pollution that endangers public health and welfare.

It stemmed from the 2007 Supreme Court decision in Massachusetts v. EPA, which required the EPA to assess whether GHGs fit the Clean Air Act’s definition of pollutants.

This enabled subsequent rules like vehicle emission standards, tailpipe regulations, and aspects of power plant and industrial controls.

_________________________________________________________________________________________________________

EPA Revokes Endangerment Finding: What You Need to Know

From The Institute for Energy Research

Kenny Stein

EPA’s Regulatory Overreach on GHGs

The EPA’s claim of authority over greenhouse gases under the Clean Air Act effectively gives it control over nearly all human activity—including respiration—since GHGs are ubiquitous byproducts. This violates the major questions doctrine, which requires clear and explicit congressional authorization for such sweeping powers. No such authorization exists.

No Congressional Intent for Broad GHG Regulation

Congress designed the Clean Air Act to address toxic compounds and visible pollution, not greenhouse gases. Legislative history shows repeated rejection of broad GHG controls: failed cap-and-trade proposals, limited and later-weakened methane provisions, and separate laws targeting specific GHGs, like HFCs, all indicate that Congress deliberately excluded broad GHG regulation from the Clean Air Act.

Direct Conflict Between CAA and CAFE Standards

Regulating CO₂ emissions from vehicle tailpipes under the Clean Air Act conflicts with Congress’s separate Corporate Average Fuel Economy (CAFE) program, which was created specifically to address fuel efficiency. The Clean Air Act was intended to address toxic emissions that can be reduced with add-on technologies such as catalytic converters, not to regulate inherent combustion byproducts such as CO₂.

Flaws in the Massachusetts v. EPA Decision

The 2007 Supreme Court ruling interpreted the Clean Air Act to include greenhouse gases, but this broad reading is now contradicted by the major questions doctrine. The term “pollutant” in the Act should apply to substances causing direct toxic harm, not indirect climate effects from GHGs. Otherwise, the statute could absurdly extend to regulating water vapor or other natural byproducts.

Indirect and Speculative Nature of Claimed GHG Harms

Greenhouse gases do not directly harm human health. Any alleged harms are indirect, projected far into the future, and rest on climate model scenarios rather than clear, observed evidence of imminent danger beyond general temperature increases. Regulating based on potential future risks does not fit the Clean Air Act’s framework for addressing immediate pollutants.

Weak Scientific Foundation for the Finding

The 2009 endangerment finding relies heavily on climate models driven by extreme, implausible emissions scenarios that overestimate future emissions and produce alarmist projections unsuitable for policymaking. The EPA should limit its analyses to more realistic and plausible emissions pathways for credible, policy-relevant assessments.

Rescinding the 2009 Endangerment Finding

The EPA is correct to rescind the 2009 Endangerment Finding to restore alignment with congressional intent and recent Supreme Court precedents. If greenhouse gas regulation is desired, Congress—not the EPA—must pass specific legislation clearly defining the authority, purpose, and objectives.

Read the Institute for Energy Research’s full comment on the Reconsideration of 2009 Endangerment Finding and Greenhouse Gas Vehicle Standards.