Democratic States Sue EPA Over Climate Endangerment Finding Repeal

A coalition of approximately 24 Democratic-led states and dozens of cities and counties filed a lawsuit in the U.S. Court of Appeals for the District of Columbia Circuit to challenge the repeal of the 2009 endangerment finding. The scientific determination, established during the Obama administration, concluded that greenhouse gases threaten public health and welfare, serving as the legal foundation for federal regulations on vehicle emissions and power plants under the Clean Air Act.

Donald Trump and EPA Administrator Lee Zeldin characterized the February 2026 rescission as the largest deregulatory action in U.S. history, claiming it would save Americans over $1.3 trillion by removing compliance requirements. The administration described the original ruling as the basis for a "Green New Scam."

Led by Attorneys General from New York, California, and Massachusetts, the plaintiffs argue the repeal ignores decades of scientific evidence and violates federal law. New York Attorney General Letitia James asserted the administration chose denial over critical protections, while California Governor Gavin Newsom cited an unprecedented March heat wave as evidence of the urgency. The lawsuit seeks to reverse the repeal and reinstate emission standards for vehicle manufacturers.

The United States Environmental Protection Agency defended the move, stating that the 2009 finding lacked the statutory authority to regulate vehicle emissions for global climate concerns. EPA spokesperson Brigit Hirsch dismissed the legal challenge as being motivated by politics rather than the merits of the law. This case is expected to be consolidated with a similar challenge filed by environmental advocacy groups in February.