The Trump administration is moving to revoke a long-standing Obama-era finding that has served as the scientific and legal foundation for U.S. climate rules, a change the White House said will substantially roll back federal regulation. The Associated Press reported that the Environmental Protection Agency will publish a final rule rescinding the 2009 government determination that carbon dioxide and other greenhouse gases endanger public health and welfare.
White House press secretary Karoline Leavitt said President Donald Trump and EPA Administrator Lee Zeldin will “formalize the rescission of the 2009 Obama-era endangerment finding” at a ceremony at the White House. Leavitt also said the effort would be the largest deregulatory action in American history and described it as saving Americans $1.3 trillion in regulations, with EPA projections pointing to savings driven largely by reduced costs for new vehicles.
The endangerment finding has anchored the federal approach to greenhouse-gas regulation under the Clean Air Act, which is used to justify a wide range of requirements affecting motor vehicles, power plants and other pollution sources, the Associated Press said. Those climate rules, it said, are intended to protect against threats increasingly linked to climate change, including deadly floods, extreme heat waves and catastrophic wildfires in the United States and elsewhere.
The White House and EPA framed the planned repeal as a shift away from what they call overreach. The Associated Press reported that EPA press secretary Brigit Hirsch characterized the Obama-era rule as “one of the most damaging decisions in modern history” and said the EPA is “actively working to deliver a historic action for the American people.”
Opponents said the change will trigger litigation. Earthjustice President Abigail Dillen told the Associated Press that the administration is “abandoning its core responsibility to keep us safe from extreme weather and accelerating climate change,” adding that “There is no way to reconcile EPA’s decision with the law, the science and the reality of disasters that are hitting us harder every year,” and that Earthjustice and partners will challenge the decision in court.
Supporters of undoing the finding have argued it was created by Democrats and is economically harmful. The Associated Press reported that Zeldin previously criticized earlier efforts to combat climate change, saying they were “willing to bankrupt the country” and describing the endangerment finding as enabling broad vehicle, airline and stationary-source regulation that could “regulate out of existence” parts of the economy, while “cost[ing] Americans a lot of money,” in remarks tied to the proposal he made last July.
Environmental advocates, however, argued that removing the finding would come at a health and safety cost. The Associated Press reported that Peter Zalzal, a lawyer and associate vice president of the Environmental Defense Fund, said the EPA would be encouraging more climate pollution, higher health insurance and fuel costs, and “thousands of avoidable premature deaths,” and that he and others viewed the focus on industry costs as ignoring the rule’s climate and health benefits.
The Associated Press said the endangerment finding has already been tested in court, and that the Supreme Court upheld in 2007 a Massachusetts v. EPA decision that planet-warming greenhouse gases are air pollutants under the Clean Air Act. It reported that since that ruling, courts have uniformly rejected legal challenges to the endangerment finding, including a 2023 decision by the U.S. Court of Appeals for the District of Columbia Circuit.
The Associated Press also pointed to a reassessment of the science behind the 2009 finding. It said that after Zeldin proposed repealing the rule, the National Academies of Sciences, Engineering and Medicine concluded in a September report that the 2009 finding was “accurate, has stood the test of time, and is now reinforced by even stronger evidence,” and that the evidence for current and future harm to human health and welfare created by human-caused greenhouse gases is “beyond scientific dispute,” according to the panel.
The EPA’s planned revocation of the endangerment finding is expected to open a new front in legal battles over what the Clean Air Act requires and what climate science means for U.S. regulatory authority.