President Donald Trump is taking aim at a mainstay of environmental protection: the 2009 endangerment finding that buttresses U.S. climate action.
It’s an ambitious undertaking that the first Trump administration elected not to pursue. And now one of the key players in the 2007 Supreme Court case Massachusetts v. EPA that led to the endangerment finding is arguing that a decision that the high court issued between the two Trump presidencies will make toppling the declaration even more difficult.
“It’s become so much easier to defend,” said David Bookbinder, director of law and policy at the Environmental Integrity Project, noting that the Supreme Court in the 2024 ruling Loper Bright v. Raimondo overturned the longstanding Chevron doctrine that gave federal agencies a leg up in defending their rules in court. “The legal predicate for the endangerment finding is now stronger than it was before, after Loper Bright.”
Bookbinder was the top climate lawyer at the Sierra Club when environmental groups and 12 states sued the George W. Bush administration, seeking to force EPA to act on climate. EPA’s challengers, he said, were operating under the constraints of the Chevron doctrine and were reluctant to make it appear as though there were any ambiguities in the Clean Air Act, which would have given the agency’s lawyers an advantage in court.
