On February 12, 2026, the U.S. Environmental Protection Agency formally rescinded the 2009 “endangerment finding,” the scientific determination that greenhouse gases “endanger public health and welfare” under the Clean Air Act. The finding, originally issued on December 7, 2009, had provided the legal foundation for federal regulation of carbon dioxide and other greenhouse gases from vehicles, power plants and major industrial sources.
The 2009 determination followed the Supreme Court’s April 2, 2007 ruling in Massachusetts v. EPA, which held that greenhouse gases qualify as pollutants under federal law and required the agency to decide whether such emissions pose a danger to public health. That decision compelled the EPA to review climate science and ultimately regulate greenhouse gas emissions.
By repealing the finding, the agency effectively removes its core authority to regulate greenhouse gas emissions under the Clean Air Act, opening the door to rolling back vehicle emissions standards, fuel-efficiency requirements and potential limits on power-sector pollution. The action represents one of the most sweeping federal climate policy reversals in nearly two decades.
President Donald Trump called the repeal “the largest deregulatory action in American history,” while EPA Administrator Lee Zeldin said the move was intended to “restore the rule of law” and reduce regulatory burdens on industry and consumers.
Multiple states and environmental organizations have signaled plans to challenge the repeal in federal court, arguing that the agency cannot overturn established scientific findings without substantial justification. The outcome of those expected lawsuits could determine whether federal greenhouse gas regulation can be reinstated — or whether Congress would need to pass new legislation to reestablish that authority.
Because the United States is one of the world’s largest greenhouse gas emitters, the repeal carries significant global implications, potentially affecting international climate commitments and the trajectory of global emissions reduction efforts.
