The Supreme Court returns to the bench Monday to open its new term with a direct clash over power: whether Boulder, Colorado, can haul fossil-fuel producers into state court for global climate harms.
Exxon Mobil and Suncor Energy want the justices to shut down the city’s 2018 damages suit as barred by federal law and the Constitution. The Trump administration, West Virginia, and dozens of allied states are backing the companies. A decision is expected by summer of 2027.
CBS News reported that the fight reaches Washington after Colorado’s high court sided with the city and county of Boulder, and after lower state proceedings refused to end the case. The justices have also ordered briefing on whether they even have jurisdiction to review that Colorado ruling.
Boulder officials filed the lawsuit in state court in 2018 and raised five claims under state law. They allege the companies’ production and allegedly deceptive marketing caused or contributed to climate change and to local harms, including extreme heat, wildfires, and ecosystem damage. The suit seeks money damages for past and future costs.
Exxon and Suncor tried to move the case to federal court and failed. They then sought dismissal in Boulder County District Court on the ground that federal law forecloses the claims. The district court denied that motion. The companies next asked the Colorado Supreme Court to step in. It sided with Boulder. Suncor and Exxon then took the dispute to the U.S. Supreme Court.
Suncor operates two oil refineries in Colorado. Exxon is the nation’s largest energy company. Dozens of similar suits by states and local governments have been filed against energy companies in state courts across the country.
Just The News reported that the Boulder matter traces to a 2018 action by Boulder and San Miguel County seeking damages tied to weather events allegedly linked to fossil fuels and to accusations of deception. Parallel climate suits have been dismissed in Pennsylvania, New Jersey, Delaware, and Maryland, creating a split with rulings that allowed cases to proceed in Colorado and Hawaii.
In Supreme Court filings, lawyers for Exxon and Suncor argue the Constitution, the Clean Air Act, and foreign-affairs concerns preclude state claims aimed at harms from interstate greenhouse-gas emissions. They say the Clean Air Act did not invite state tort law to referee interstate pollution disputes.
The companies warn of a free-for-all in local courts.
"it would authorize all fifty States, the tens of thousands of municipalities, and even the hundreds of millions of individuals in our country to ask local courts to establish countless, conflicting climate policies for the Nation."
They add that such cases would create “an end-run around the United States' existing diplomatic channels for addressing climate change in favor of innumerable state judicial ones.” They also argue that “the imposition of potentially devastating liability on fossil-fuel producers will undercut the government's pursuit of primacy in global energy production.”
The Trump administration supports Exxon and Suncor. It argues the suit invites needless diplomatic friction with foreign countries where the companies produce and sell fossil fuels.
In material highlighted by Just The News, the Justice Department framed the core issue in blunt constitutional terms.
"This case presents a basic question: Can one city wield one State’s law to dictate how the rest of the world must address a global problem with global effects? The Constitution supplies the answer: Absolutely not."
West Virginia and 25 other states are also backing Suncor and Exxon. They say Boulder’s lawsuit jeopardizes their ability to set their own energy and environmental policy goals.
Michael Williams, solicitor general of West Virginia, told reporters during a Wednesday briefing that climate policy is not a patchwork job for local tort suits.
"It's a national problem, so it requires a national solution."
Williams drew a sharp line between in-state regulation and global liability theories. “We don't take issue with the idea that a state can actually regulate sources within its own borders. So if West Virginia wants to regulate a coal plant in West Virginia, we claim the right to do that,” he said. “In the same way, if Colorado wants to regulate emissions coming from Colorado in Colorado, they're free to do that as well. What they're not free to do is say, hey you emitters, anywhere in the world... we're going to make you pay money for any of those emissions anywhere in the world.”
Just The News also reported a broad amicus effort behind the companies, including 78 members of Congress, 27 state attorneys general, Colorado counties, Native American tribes, and industry groups. West Virginia Attorney General JB McCuskey cast the suit as ideology dressed up as tort law.
"States, cities or municipalities cannot use local laws to impose their far-left ideology on the rest of the country. This is an attempt to fill their coffers at the expense of the rest of the nation."
Lawyers for the city and county of Boulder urge the Supreme Court to dismiss the appeal for lack of jurisdiction. If the Court keeps the case, they ask it to uphold the Colorado Supreme Court.
In their filing they put the constitutional question this way: “Does anything implicit in the Constitution bar this suit?” Their answer: “Nothing does.” They argue that “climate change is a global problem does not disempower states from redressing its local harms either.”
Boulder’s counsel insist the case is not a bid to run national climate policy from a county courthouse.
"This litigation is not an attempt to solve climate change; it merely asks that petitioners bear their fair share of local costs incurred in part because of their tortious conduct."
They also separate marketing claims from emissions control. “Indeed, avoiding liability would not require reducing emissions at all, only telling the truth, so the public can make informed consumption decisions free of the distorting effect of petitioners' misrepresentations,” their filing states. They argue the Clean Air Act governs emissions, not upstream producers’ conduct and allegedly deceptive marketing.
Jonathan Adler, a William & Mary law professor who filed a friend-of-the-court brief supporting Boulder, stressed what is and is not before the justices. “This is not a judgment about whether these cases will succeed. It's a judgment about whether folks get to make their case,” he said. “And even if they get to make their case, the scope of what they can pursue could well be narrowed and might well be narrowed significantly.”
Adler pushed back on sweeping foreign-affairs preemption theories tied to executive preference alone. He said that approach “seems to suggest that any time the executive branch claims that it would like to negotiate in a space that could be implicated by companies being held liable for damages that they may have contributed to, that would really give the executive branch the ability to preempt any sort of litigation that it wanted. That can't be the law.” He added, “If there was an actual conflict between an actual treaty, of course that could preempt state law. But we don't even have that.”
He also pointed to Congress. “If Congress believes that what's going on here is a combination of plaintiffs' lawyers and activists trying to make energy less available or less affordable, or to otherwise create pressure on fossil-fuel companies, Congress has the tools to address that,” Adler said. “That's a job for the legislature, not a job for the courts.” He noted a 2005 federal law that shields gun manufacturers from certain civil lawsuits as an example of legislative line-drawing.
Adler further noted that the Trump administration has withdrawn from international agreements aimed at global warming and greenhouse-gas emissions, undercutting claims that state damages suits must yield to ongoing diplomatic architecture in that field.
Only eight justices will hear the case. Justice Samuel Alito recused himself. The Court said last week he chose to step aside and gave no reason. His 2025 financial disclosure shows individual holdings in ConocoPhillips and Phillips 66. It does not show individual stocks in Exxon or Suncor.
Breitbart reported that arguments are set for Oct. 5 in Suncor Energy Inc. v. County Commissioners of Boulder County, and that Supreme Court Clerk Scott Harris conveyed Alito’s decision that he “will not continue to participate.” Breitbart also reported that a coalition had asked the Senate Judiciary Committee to examine Alito’s oil and gas holdings; that he had stayed out of an earlier related decision; and that he had participated in the grant of review. The Court’s code of conduct says a justice should step aside when a reasonable person familiar with the circumstances might question the justice’s impartiality.
With Alito out, a 4-4 division would leave the Colorado Supreme Court decision in place. Even a win for Boulder at the U.S. Supreme Court would not guarantee an ultimate win on the merits in state court. The justices are deciding whether the claims may proceed, not whether Boulder has proved them.
The companies cast the case as a national systems problem: conflicting local climate “policies” imposed through damages verdicts, pressure on energy production, and friction with federal foreign-affairs and statutory frameworks. Boulder casts it as ordinary tort accountability for local costs and alleged deception. States aligned with the companies cast it as one locality attempting to export its preferences nationwide.
Investigators of the legal question before the Court will have to determine whether state tort law can reach alleged global emissions-related harms and marketing conduct of this kind, whether the Clean Air Act and constitutional structure displace those claims, and whether the Supreme Court has jurisdiction over the Colorado Supreme Court’s ruling. No public merits judgment on liability has been entered. No damages award has been fixed. The procedural posture remains a gatekeeping fight with nationwide follow-on effects for the many similar state-court actions already filed.
When local officials use state tort suits to set the terms of national energy and climate policy, voters lose the chain of accountability the Constitution assigns to Congress and to the states within their own borders. The Court’s task is to say who governs, and by what law, before the courthouse becomes the regulatory agency of last resort.
