A regulatory pillar that has quietly underpinned U.S. climate policy for more than a decade is about to be pulled away — and the aftershocks may be felt less in Washington than in courtrooms across the country.
The Trump administration is preparing to revoke a 2009 scientific determination that greenhouse gases endanger public health. That finding has long served as the legal backbone for federal limits on carbon dioxide, methane and other heat-trapping emissions under the Clean Air Act. Its removal would mark a dramatic shift in federal climate posture.
But the rollback could carry consequences that stretch far beyond deregulation.
Legal scholars say dismantling the so-called “endangerment finding” may reopen a pathway that had largely been sealed shut since 2011: public nuisance lawsuits against major emitters. These cases argue that companies contributing to climate change are interfering with public health and safety — a doctrine historically used in disputes over pollution and hazardous activities.
Fifteen years ago, several states tested that theory in a case against large power producers, contending their emissions amounted to a public nuisance. The dispute climbed to the U.S. Supreme Court, which ruled unanimously that greenhouse gas regulation belonged with the Environmental Protection Agency, not federal judges. Because the Clean Air Act provided a regulatory framework, the Court concluded, nuisance claims were effectively displaced.
Now, with the EPA poised to retreat from that framework, that judicial shield may no longer hold.
“If the statutory structure disappears, the reasoning that blocked those cases weakens,” said one environmental law professor, noting that courts could interpret the absence of federal regulation as an invitation for common-law claims to proceed.
Industry groups have largely welcomed broader deregulatory efforts but are wary of unintended consequences. Utilities have cautioned that scrapping the endangerment finding could spark a surge of litigation, regardless of whether such cases ultimately succeed. Even meritless suits can impose heavy legal costs and reputational risks.
Public nuisance claims are notoriously difficult to win. Plaintiffs must show that a specific company’s emissions can be tied directly to particular climate harms — a complex scientific and legal challenge. Still, these suits remain an attractive tool for states and municipalities seeking compensation for rising sea levels, wildfire damage, or extreme weather costs.
Legal observers suggest that the EPA’s withdrawal could alter the balance that has prevailed since the Supreme Court’s 2011 ruling. Without an active federal regulatory scheme addressing greenhouse gases, judges may find fewer grounds to dismiss nuisance claims at the outset.
What was once considered settled terrain may no longer be so settled.
For power producers and other heavy emitters, the administration’s move could mean trading regulatory oversight for courtroom exposure. And for climate-focused plaintiffs, it may signal that a door long thought closed is quietly swinging open again.
