type: timeline_event
The EPA's final rule rescinding the 2009 Greenhouse Gas Endangerment Finding was published in the Federal Register on February 18, 2026 (Vol. 91, No. 32), setting an effective date of April 20, 2026. Within hours, two separate coalition lawsuits were filed in the U.S. Court of Appeals for the District of Columbia Circuit, initiating what legal experts expect to be years of major constitutional and statutory litigation.
The first lawsuit was filed by Earthjustice representing the Center for Community Action and Environmental Justice, Clean Air Council, Friends of the Earth, Physicians for Social Responsibility, Rio Grande International Study Center, and the Union of Concerned Scientists. The second petition was filed by a coalition including NRDC, Environmental Defense Fund, Center for Biological Diversity, Conservation Law Foundation, Environmental Law and Policy Center, Public Citizen, and the Sierra Club. The American Public Health Association and American Lung Association joined as additional plaintiffs, citing projected public health consequences of the repeal that independent analysts estimated could cause up to 58,000 additional deaths over 20 years from heat waves, floods, fires, and droughts, at a cost of up to $4.7 trillion in damages.
The legal challenge rests primarily on Massachusetts v. EPA (2007), in which the Supreme Court held that carbon dioxide is unambiguously an "air pollutant" under the Clean Air Act and directed the EPA to make a scientific determination about whether greenhouse gases endanger public health. Legal scholars at Legal Planet and Harvard's Salata Institute noted the deep tension: the Supreme Court's ruling has never been overturned and the underlying scientific evidence for climate danger has only strengthened since 2009, leaving EPA with no credible basis to reverse the finding under the Administrative Procedure Act's "arbitrary and capricious" standard.
California Attorney General Rob Bonta announced the state would file its own separate legal challenge, stating the repeal was "a reckless rejection of decades of scientific evidence" and "a violation of well-settled law, ultimately putting the fossil fuel industry's profits ahead of the health and safety of Americans." The attorneys general of Massachusetts and Connecticut announced they were coordinating their own legal responses. The repeal also immediately ended all federal greenhouse gas emission standards for motor vehicles covering model years 2012 through 2027 and beyond, stripping away vehicle efficiency rules that EPA's own analysis found would have saved drivers an average of $6,000 over a vehicle's lifetime.