Justice Clarence Thomas could decide whether Boulder can force Exxon and Suncor to pay billions for climate damages, a fight oil companies call a backdoor carbon tax.
The Supreme Court hears arguments Monday in Suncor Energy v. Boulder, a case that asks whether cities can use state tort law to extract massive damages from energy producers over global climate claims.
Boulder, Colorado, and its county want billions from Exxon and Canadian energy firm Suncor for fires and floods they tie to rising temperatures. They also claim the companies misled the public. The producers say climate pollution crosses state lines, so federal law controls, and warn the suits would create a chaotic patchwork and an enormous “carbon tax” that could bankrupt the industry.
The Trump administration is siding with the oil companies. Justice Samuel Alito has recused himself, raising the chance of a 4-4 split that would leave a Colorado Supreme Court ruling in place without setting national precedent.
CNN reported that the justices to watch are Clarence Thomas and Neil Gorsuch, two textualists whose past preemption opinions now sit at the center of both sides’ arguments.
Colorado’s highest court allowed the suit to move forward. Fossil fuel producers appealed, and the U.S. Supreme Court agreed in February to decide the dispute.
Boulder told the justices the case is not an attempt to solve climate change.
In a filing quoted in the coverage, the city and county argued:
“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,”
Exxon and Suncor see a different goal. They told the Court the suits aim to impose huge liability through state courts.
Their argument, as presented, states:
“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,”
Dozens of other local governments have filed similar actions. A win for Boulder would open the door wider. A win for the companies would shut down this wave of state-court pressure.
Alito told Bloomberg News he felt it was “prudent” to recuse because of energy stock holdings, even though he said it was not required and the companies he holds are not named parties.
With Alito out, a tie becomes possible. A 4-4 result would uphold the Colorado decision for this case alone and set no binding national rule. The Court could also decide the dispute is not fully ready and send it back to state courts.
That math puts extra weight on Thomas and Gorsuch. Their records on when federal law actually displaces state law are now the main event. Thomas has long insisted courts stick to constitutional text and enacted statutes, a stance also visible when he addressed how the Second Amendment recognizes a right government cannot bestow.
Just five months ago, in an April opinion, Thomas wrote for a 6-3 majority in a case brought by Army specialist Winston Hencely. Hencely was severely injured by a suicide bomber at Bagram Air Base in Afghanistan and sued a military contractor for failing to supervise an Afghan employee involved in the attack.
The contractor argued that running a war is inherently federal, so state tort claims should be blocked. Thomas shut that down.
Writing for the Court, he declared:
“There is no federal preemption in vacuo, without a constitutional text or a federal statute to assert it,”
He added that the contractor “has not identified any provision of law expressly preempting” the soldier’s suit. Boulder’s latest brief cites that case four times, including in the second paragraph.
Lawyers fighting Exxon quoted Thomas and Gorsuch six times in written arguments filed over the summer. The pattern is clear: they want the Court to demand a specific statute or constitutional clause, not a general claim that climate policy feels federal.
In 2019, Gorsuch wrote the majority opinion rejecting a preemption challenge to Virginia’s ban on uranium mining. Thomas joined him. Companies had argued the federal Atomic Energy Act pushed state law aside. The Court said no.
Gorsuch’s words cut against broad “federal interest” claims:
“Invoking some brooding federal interest or appealing to a judicial policy preference should never be enough to win preemption of a state law,”
He continued:
“A litigant must point specifically to ‘a constitutional text or a federal statute’ that does the displacing or conflicts with state law.”
Appellate attorney Deepak Gupta, speaking at a Supreme Court Institute event at Georgetown Law Center, said the justices to watch “are very much Justice Gorsuch and Justice Thomas.” Gupta added he thinks they will find “the lack of any textual hook for these arguments troubling.”
Kirti Datla of Earthjustice, which filed a brief opposing Suncor and Exxon, made the same point. She said Thomas and Gorsuch have rejected the idea that federal law can shove state law aside based on “hazy arguments about a law’s intentions or policy consequences,” and that Suncor’s case boils down to exactly that.
Thomas’s willingness to separate legal text from political pressure has defined much of his tenure, including moments when critics tried to police his views and he rejected racial litmus tests on political thought.
Not every conservative voice expects Thomas and Gorsuch to side with Boulder. John Yoo, a UC Berkeley law professor, former Thomas clerk, and co-author of a brief supporting Exxon, called their approach “standard preemption doctrine.”
Yoo said the real question is whether the Framers or Congress wanted preemption in this area. If the justices back Suncor, he expects two grounds: that the Clean Air Act shows Congress did not want states interfering with national-level pollution such as greenhouse gases, and that energy regulation carries major national security and foreign policy effects.
That frames the choice cleanly. Boulder says neither the Constitution nor federal law clearly blocks ordinary state tort claims. The companies, backed by the Trump administration, say allowing every city to run its own climate damages regime would smash national energy policy into fragments.
Thomas has not been a reliable vote for environmental groups in past matters. He has opposed broad federal wetlands regulation, resisted certain power-plant emission controls, and joined a decision allowing San Francisco to pump more sewage into the Pacific. Those votes do not erase his written rule against preemption without text. They do show he draws hard lines on both sides of federal power.
Political attacks on his seat have continued for years, from expansion talk after public regrets over his confirmation to broader fights that once paired him with Alito when the two challenged a Supreme Court majority over mail-in ballot safeguards.
The question before the justices is narrow and concrete. Can state tort lawsuits over global emissions proceed, or does federal law occupy the field?
Boulder wants local compensation. Energy producers want a single national rule. Alito’s recusal removes one reliable conservative vote and raises the odds of an inconclusive tie. Thomas’s April opinion and Gorsuch’s 2019 uranium ruling give Boulder its strongest citations. The Clean Air Act and foreign-policy stakes give the companies theirs.
Nominated by President George H.W. Bush in 1991, Thomas is the Court’s longest-serving justice. His preemption writing is now being used by the same local governments that usually fight his environmental record. That reversal is the story. Cities that spent years demanding more federal climate power are suddenly discovering the value of state-law freelancing when it comes with a damages jackpot.
Thomas has also pushed back when ideology tried to dictate outcomes for Black Americans, at one point comparing ideological demands to segregation itself. The through-line is the same: text first, policy freelancing second.
Monday’s arguments will test whether “brooding federal interest” is enough to wipe out state claims, or whether the companies must show a statute that actually does the work. The Colorado ruling hangs in the balance. So does the template for every other city watching this case.
If courts can impose industry-wide climate damages without a clear act of Congress, voters lose the chance to set energy policy through elections and legislation, and trial lawyers gain a veto the Constitution never wrote.
