24 states and cities sue EPA over repeal of greenhouse gas health endangerment finding.

Twenty-four states, ten cities, and five counties led by Democratic officials sued the EPA on March 18, 2026, challenging the Trump administration’s repeal of the 2009 endangerment finding that greenhouse gases endanger public health. The lawsuit, filed in D.C. Circuit Court, argues the repeal undermines federal climate regulations and scientific consensus, risking public health and environmental protection. Plaintiffs cite a 2007 Supreme Court ruling affirming greenhouse gases are pollutants under the Clean Air Act. The EPA dismissed the suit as politically driven, asserting it reevaluated the legal basis for the finding. This marks the second major legal challenge to the repeal.