The Supreme Court will hear arguments Monday in Suncor Energy v. Boulder, a high-stakes dispute over whether cities and states can haul oil companies into court for planet-warming pollution. The justices agreed in February to take the case after fossil fuel producers appealed a ruling from Colorado’s highest court that let the city and county of Boulder’s lawsuit move forward.
Boulder wants billions of dollars in damages. It says fires and floods tied to rising temperatures left local costs that Exxon and Canadian energy firm Suncor should help cover. The companies argue climate regulation is a federal job and warn that multi-city suits would create a chaotic patchwork that works like a carbon tax and could bankrupt the energy industry.
The legal core is preemption: the idea that federal law can wipe out state tort claims. President Donald Trump’s administration is siding with the oil companies. Justice Samuel Alito Jr. has recused himself, raising the chance of a 4-4 split that would leave the Colorado decision in place without setting a national precedent.
Appellate attorney Deepak Gupta told a recent Supreme Court Institute event at Georgetown Law Center that the justices to watch are “very much Justice Gorsuch and Justice Thomas.” Gupta said he expects them to find “the lack of any textual hook for these arguments troubling.”
Lawyers fighting Exxon quoted Thomas and Gorsuch six times in written arguments filed over the summer. Boulder’s latest brief cites Thomas’s recent contractor opinion four times, including in the second paragraph. Earthjustice, which filed a brief opposing Suncor and Exxon, is pressing the same theme.
Kirti Datla, director of strategic legal advocacy at Earthjustice, said Justices Thomas and Gorsuch “have both written opinions that firmly reject the idea that federal law can shove state law out of the way based on hazy arguments about a law’s intentions or policy consequences.” She added that Suncor’s arguments boil down to that approach and “should reject this move again here.”
Those earlier writings give Boulder a concrete textualist lane. They also put two of the Court’s most consistent conservatives under a microscope in a case that could reshape energy litigation nationwide, much as other recent dockets have tested the Court’s posture toward state and federal power in fights over state election maps.
In April, Thomas wrote for a 6-3 majority in a suit brought by Army specialist Winston Hencely, who was severely injured by a suicide bomber at Bagram Air Base. Hencely sued a military contractor for failing to supervise the Afghan employee who carried out the attack. The contractor claimed the state tort case was preempted because running a war is inherently federal.
Thomas rejected that claim. “There is no federal preemption in vacuo, without a constitutional text or a federal statute to assert it,” he wrote. He also said the contractor “has not identified any provision of law expressly preempting” Hencely’s suit.
In 2019, Gorsuch wrote the majority opinion, joined by Thomas, rejecting a bid to wipe out Virginia’s uranium mining ban under the federal Atomic Energy Act. Gorsuch warned that “invoking some brooding federal interest or appealing to a judicial policy preference should never be enough to win preemption of a state law.” He added that a litigant “must point specifically to ‘a constitutional text or a federal statute’ that does the displacing or conflicts with state law.”
Boulder told the justices its case is not a bid to solve climate change. “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,” the city and county argued.
Exxon and Suncor cast the suits as a backdoor national energy policy. They told the Court the “intended effect of these lawsuits is to impose an enormous ‘carbon tax,’ in the form of billions of dollars of damages, that could ‘bankrupt’ the energy industry.” They say greenhouse gas regulation is inherently federal and that a wave of local cases would produce conflicting rules across the country.
Dozens of other local governments have filed similar suits against energy companies. The Colorado decision on appeal allowed Boulder’s claims to proceed. A Supreme Court ruling for the companies could shut down or sharply limit that model. A ruling for Boulder could open the door wider. A tie would uphold Colorado without creating binding nationwide precedent.
John Yoo, a University of California, Berkeley law professor, former Thomas clerk, and co-author of a brief supporting Exxon, called the Thomas and Gorsuch views “standard preemption doctrine.” He said the real question is how to decide whether the Framers or Congress wanted preemption “over an issue area or in a specific case.”
Yoo told CNN that if those justices back Suncor over Boulder, he expects it would be because they believe Congress, in the Clean Air Act, “did not want states interfering with national-level pollution, such as greenhouse gases,” and because energy regulation carries “significant effects” for national security and foreign policy. Federal-state conflict questions have also surfaced in recent Court action on federal tools for voter roll checks.
Justice Alito recused himself from the climate case. He told Bloomberg News the step was “prudent” given his holdings in energy stocks, though he said it was not required. The companies in his portfolio are not named parties in the Boulder suit.
Alito attended President Trump’s inauguration in the Rotunda of the U.S. Capitol on January 20, 2025. With him out, an even split becomes a live scenario. That outcome would leave the Colorado Supreme Court decision standing for the parties while avoiding a nationwide rule either way.
Procedural posture matters as much as politics here. The Court could also send the dispute back if it finds the claims are not ripe. Investigators of the legal record will need to determine how far state tort law can run when the alleged harm is global in nature and the regulatory field is already crowded with federal statutes. Similar fault lines over Court majorities and dissents appeared when the justices blocked mail ballot rules in a 7-2 decision.
Clarence Thomas is the Court’s longest-serving current justice, nominated by President George H.W. Bush in 1991. He has consistently sided against environmentalists in various matters, opposed federal wetlands regulation, balked at efforts to reduce power plant emissions, and joined a decision allowing San Francisco to pump more sewage into the Pacific Ocean. He also once worked as a lawyer for the agrochemical industry.
That history makes his textualist preemption opinions sharper, not softer. Boulder is not asking him to become an environmentalist. It is asking him to apply the same rule he used for a wounded soldier and a uranium ban: no preemption without a clear constitutional or statutory hook.
Gorsuch has followed a parallel line, often skeptical of federal displacement of state law when Congress has not spoken plainly. Together they give the companies a problem that pure policy arguments may not fix. The companies still hold a strong institutional card in the Trump administration’s support and in the claim that greenhouse gases are a national and international problem, not a municipal tort.
How the Court handles that clash will signal whether local governments can keep using state courts as a damages forum, or whether climate suits of this type must live or die in Washington. Parallel tensions between state authority and federal oversight have run through other recent litigation, including the fight that saw a federal appeals court reinstate Missouri’s congressional map.
Boulder alleges the companies contributed to climate-driven disasters and misled the public. The companies deny that state tort law is the right tool and say the suits aim at industry-wide financial pressure. No conviction or liability finding is on the table Monday. The question is whether the claims may proceed at all.
Authorities have not publicly framed the case as a referendum on every environmental statute. It is a preemption case with massive practical reach. Billions are sought in Boulder alone. Dozens of similar local suits wait in the wings. Energy investment, insurance, and municipal budgets all sit downstream of whatever rule the Court adopts or declines to adopt.
For conservatives who prize clear text and limited freelancing by courts, the Thomas and Gorsuch line is familiar doctrine, not a surprise. For industry, the fear is a patchwork of juries setting national energy policy one city at a time. For Boulder, the pitch is simpler: local costs, local courts, and defendants who should pay their share if tort law reaches them.
Monday’s argument will test which story commands five votes. With Alito out, four may be enough only to freeze the status quo in Colorado. A full majority either way would travel farther. The Court has not said how quickly it will rule after argument, and no public timetable beyond the Monday hearing has been released in the materials at hand. Separate election-administration cases have likewise left advocates reading oral-argument tea leaves, including after signals on mail ballot deadlines.
Nearly two decades have passed since the Court’s last major climate-related turning point of this scale, as framed in the reporting. Suncor Energy v. Boulder now puts state tort power, federal energy policy, and textual preemption in the same frame. Thomas’s April opinion and Gorsuch’s 2019 uranium decision are no longer background. They are the cited playbook.
The companies want a federal gate. Boulder wants a state courtroom. The administration backs the federal gate. Alito has stepped away. Thomas and Gorsuch must decide whether “brooding federal interest” is enough, or whether Congress must speak first.
When local governments and national energy policy collide, the Constitution’s allocation of power is not a press release. It is the whole ballgame.
