The Supreme Court heard oral arguments on Tuesday in Suncor Energy v. County Commissioners of Boulder County, a climate-related lawsuit that could reshape how thousands of local governments pursue fossil fuel companies across the country. The case centers on whether Boulder County’s state court claims against Exxon Mobil Corporation and Suncor Energy—alleging deception about climate change impacts—can proceed despite federal preemption concerns.
The Core Legal Battle
The dispute stems from lawsuits filed by over three dozen local governments and states against fossil fuel companies, accusing them of allegedly deceiving the public about their products’ role in climate change. None have reached trial, but the Supreme Court decided to review Boulder’s case at the request of the oil company petitioners. The central question: do federal environmental laws preempt these state tort claims?
During arguments, several justices expressed skepticism about the oil companies’ broadest theory; that the Constitution’s structure alone bars such suits. Justice Kagan challenged the “plan of the Convention” argument, asking, “Where’s the text for that? Where’s the support for that? Where’s the precedent for that?”
Two Narrower Paths to Preemption
The real fight was over two narrower routes. Justice Kavanaugh argued that four precedents (Milwaukee I, Milwaukee II, International Paper Co. v. Ouellette, and American Electric Power v. Connecticut) make ‘crystal-clear that interstate air and water pollution are matters for federal law unless Congress specifically preserves state law.’ He contended the Clean Air Act’s structure-specifically its “source state” provisions-means only Colorado law governing emissions originating in the state applies, not lawsuits under Colorado law addressing harms elsewhere.
Justice Kagan pointed to AEP’s closing paragraph, which says that whether a state suit is available depends on the preemptive effect of the Clean Air Act. She suggested the statute itself, not constitutional structure, should govern the outcome.
Both approaches could significantly limit Boulder’s claims. Kavanaugh noted the Clean Air Act preserves suits under the law of the pollution’s source state, not the injured state like Colorado. Kagan questioned whether the Act’s language supports broad state tort claims when it was designed to address interstate pollution uniformly.
Differing judicial perspectives
Justices Sotomayor and Jackson appeared skeptical of preemption arguments, comparing the case to Commonwealth Edison v. Montana, which upheld a state coal tax despite federal environmental laws.
Justice Barrett rejected the companies’ constitutional-structure theory but acknowledged tort law’s regulatory effect. She noted the Clean Air Act’s savings clauses preserve preexisting state authority, though that authority is “much more circumscribed.” Her hypothetical of a Colorado statute capping emissions in other states, which Boulder’s counsel agreed would be invalid, raised questions about whether tort claims could achieve similar effects indirectly.
Chief Justice Roberts expressed concern about potential mass tort litigation, asking if Boulder’s suit was “an attempt to evade” prior decisions. Justice Gorsuch highlighted a logical gap in petitioners’ argument, noting their objection would apply even to Texas law governing Texas-based pollution, and questioned whether EPA’s recent regulatory disclaimers left no remedy at all.
Boulder’s Unraised Argument on State Tort Precedents
Key cases such as Silkwood v. Kerr-McGee (1984) and Goodyear Atomic Corp. v. Miller (1988) illustrate this principle. In Silkwood, the Court upheld a nuclear industry tort claim despite federal oversight, noting Congress intended to “tolerate whatever tension there was” between federal safety rules and state remedies. Similarly, Goodyear validated enhanced state workers’ compensation for safety violations at a federal facility, treating the award’s regulatory effect as acceptable. These rulings suggest the Court could apply similar logic to climate-related tort claims.