The Environmental Protection Agency's recent rescission of a 2009 scientific determination that greenhouse gases endanger public health and welfare has legal experts warning of a potential resurgence in litigation against major emitters. The 2009 "endangerment finding" had been the basis for federal climate rules under the Clean Air Act of 1963; the EPA announced on Thursday that it has repealed that finding.
Legal analysts say the policy reversal could reopen a path for so-called public nuisance suits that seek to hold companies responsible for contributing to climate harms. Under this line of litigation, state and local governments typically sue to require defendants to abate conditions that unreasonably interfere with community health and safety.
Those public nuisance claims were largely constrained after a unanimous U.S. Supreme Court decision in 2011, which held that regulation of greenhouse gases should be handled by the EPA under the Clean Air Act rather than by the courts. Writing for the court, Justice Ruth Bader Ginsburg said such statutory and agency action "displace the claims the plaintiffs seek to pursue." With the EPA now stepping away from the regulatory effort founded on the endangerment finding, legal observers say the precedent that protected defendants in federal court may unravel.
"This may be another classic case where overreach by the Trump administration comes back to bite it," said Robert Percival, a University of Maryland environmental law professor, reflecting a view among some scholars that the rollback of the regulatory finding could produce unintended legal consequences.
EPA Administrator Lee Zeldin described the agency's move as "the largest act of deregulation in the history of the United States." Power companies, which have generally supported the administration's broader deregulatory agenda, have expressed concerns that abandoning the endangerment finding could instead spur litigation.
The Edison Electric Institute, which represents publicly traded electric utilities, warned in September that rescinding the endangerment finding carries the "potential for increased litigation alleging common-law claims, regardless of the merits of those suits." The trade group has noted that legal exposure could rise even if the merits of individual cases are uncertain.
How public nuisance litigation works
Public nuisance is a longstanding legal theory that prohibits conduct which unreasonably interferes with the health and safety of a community. Governments most commonly bring these cases, seeking court orders that require the responsible parties to repair or abate the harmful condition. Historically, such claims have been difficult to win in the climate context, in part because proving direct causation between a specific defendant's emissions and particular climate harms is legally challenging.
Still, environmental advocates have viewed public nuisance suits as one tool to hold large greenhouse gas emitters accountable. An earlier example is a 2004 lawsuit in which California and five other states alleged major power companies had created a public nuisance by contributing to climate change. Defendants in that case included American Electric Power and Xcel Energy. The dispute ultimately reached the Supreme Court, which in 2011 ruled against the states and effectively routed greenhouse gas regulation through the EPA.
With that statutory and regulatory framework now withdrawn by the agency, some scholars predict that public nuisance claims could again proceed in court. "This has the potential to change the stakes of the game," said University of Pennsylvania law professor Sarah Light. She added, "If the Clean Air Act no longer applies to greenhouse gas emissions, then there’s no comprehensive statutory scheme in which Congress intended to displace nuisance claims, so they would likely be able to proceed in court."
Meghan Greenfield, an environmental attorney at Jenner & Block, concurred that a "new front" for litigation may be opening. "This is an area where things had been settled for the past 15 years, and, especially as the EPA steps out of this space for regulation, you can imagine others wanting to push those fronts ever harder," Greenfield said.
Practical implications and where uncertainty remains
Observers note that while the repeal of the endangerment finding removes a prominent regulatory shield, practical obstacles to succeeding in public nuisance claims persist, including causation and the suitability of courts to resolve complex, global environmental harms. Some state court cases have survived despite the federal precedent, highlighting that litigation outcomes can vary across jurisdictions.
Power producers and other industries that were previously insulated in federal court may now face renewed legal scrutiny, at least in some states. The full scale and speed of any increase in lawsuits remains uncertain, but the combination of the EPA's withdrawal of the scientific determination and vocal legal commentary suggests a shift in legal dynamics that companies and governments will be watching closely.
For now, the situation is defined by the agency's action to repeal the endangerment finding and the legal commentary suggesting that public nuisance claims could regain traction as a result. How courts respond in specific cases will determine whether the warning of a new litigation front materializes into a wave of successful suits against emitters.