The Supreme Court is preparing to hear a major climate liability case that could determine whether state and local governments may use state law to seek damages from oil companies over alleged climate-related harms. ExxonMobil and Suncor Energy are asking the justices to block a lawsuit brought by Boulder, Colorado, in a dispute that could influence nearly 60 similar cases around the country.
The case turns on whether claims accusing oil companies of contributing to climate change and misleading the public about fossil-fuel risks are governed by federal law or may proceed under state causes of action. The outcome could affect dozens of climate lawsuits seeking billions of dollars in damages, making the dispute one of the most consequential business cases on the Supreme Court’s new term.
Supreme Court Climate Lawsuit Tests State Authority
Boulder and Boulder County sued Exxon and Suncor in 2018, arguing that the companies helped drive climate change while misleading the public about the risks associated with fossil fuels. The local governments seek compensation for costs they say are linked to extreme heat, wildfire risk, drought and other climate-related impacts.
The oil companies deny wrongdoing and argue that the claims are effectively an attempt to regulate global greenhouse-gas emissions through state tort law. They contend that such questions are national and international in scope and therefore must be governed by federal law rather than a patchwork of state standards.
The legal distinction is crucial because federal law can preempt state claims when Congress has occupied a field or when state rules conflict with federal policy. Exxon and Suncor argue that the Clean Air Act and broader federal authority over interstate emissions leave no room for the type of damages claims Boulder is pursuing.
Boulder Says the Case Is About Deception and Local Costs
Boulder disputes the companies’ characterization of the lawsuit as emissions regulation. Its lawyers say the case is about corporate conduct, public representations and the local costs allegedly caused by products the companies sold and promoted.
That framing allows Boulder to rely on state-law theories involving nuisance, consumer protection and deceptive practices. The local governments argue they are not asking a court to set national emissions limits or control how much oil and gas companies may produce.
The companies say that distinction is artificial because any liability award would ultimately punish activity involving worldwide fossil-fuel production and consumption. They warn that allowing dozens of state and local lawsuits to proceed could create inconsistent standards and impose enormous costs on an industry that supplies energy across state and national borders.
Nearly 60 Climate Cases Could Be Affected
The Boulder dispute is part of a larger wave of lawsuits brought by states, cities and counties against major oil producers. Those cases generally allege that companies knew for decades that fossil-fuel use contributed to climate change while publicly minimizing or disputing the risks.
Oil companies have repeatedly tried to move the lawsuits into federal court or have them dismissed on federal-preemption grounds. In March 2025, the Supreme Court declined a separate effort by Republican-led states to block climate suits brought by Democratic-led states, leaving those cases to continue.
The current case is different because Exxon and Suncor are directly challenging the legal foundation of Boulder’s claims. A broad ruling for the companies could give defendants a powerful tool to dismiss similar lawsuits, while a ruling for Boulder could strengthen the ability of state and local governments to pursue damages under their own laws.
Trump Administration Backs the Oil Companies
The Trump administration supports Exxon and Suncor, arguing that climate policy involving interstate and global emissions should be handled by the federal government. That position aligns with the administration’s broader approach of limiting state efforts that it views as imposing national energy policy through local regulation or litigation.
The federal government’s involvement raises the stakes because the Supreme Court often gives weight to the solicitor general’s view on questions involving federal authority. At the same time, the justices are not required to adopt the administration’s legal position.
The case therefore sits at the intersection of environmental law, federalism and separation of powers. A decision focused narrowly on preemption could reshape climate litigation without deciding whether the companies’ past public statements were accurate or misleading.
Justice Alito Will Not Participate
Justice Samuel Alito will not participate in the case, reducing the number of justices hearing the dispute to eight. Reuters reported that Alito has financial interests in other oil companies involved in related litigation, although he does not hold stock in Exxon or Suncor.
An eight-justice court creates the possibility of a 4-4 split. If that happens, the lower-court ruling would remain in place without creating a nationwide Supreme Court precedent, leaving similar disputes to continue in other jurisdictions.
Alito’s absence may be especially notable because he is one of the court’s most conservative members and has generally favored limits on expansive environmental regulation. Still, the case presents legal questions that do not map perfectly onto traditional ideological lines because it concerns both state authority and the reach of federal law.
Billions of Dollars and Energy Policy Are at Stake
The direct financial exposure in climate litigation could be enormous if state and local governments begin winning damage awards. Plaintiffs are seeking compensation for infrastructure, public-health and disaster-response costs they attribute in part to climate change.
Oil companies argue that those costs cannot fairly be assigned through individual state lawsuits because climate change results from global economic activity involving billions of consumers, governments and businesses. Plaintiffs respond that companies can still be held responsible for deceptive conduct even if they were not the sole cause of the underlying harm.
The Supreme Court does not need to decide the scientific reality of climate change to resolve the case. The core question is whether state courts may hear these claims and apply state law or whether federal law forecloses them before a trial ever begins.
The Ruling Could Define the Next Phase of Climate Litigation
If Exxon and Suncor prevail on a broad federal-preemption theory, many climate cases could be dismissed or sharply narrowed. Such a decision would shift the battle away from state tort litigation and toward Congress, federal agencies and traditional environmental statutes.
If Boulder wins, climate plaintiffs would gain a clearer path to discovery and trial, potentially forcing companies to disclose internal records and defend historical public statements before juries. That possibility could also increase settlement pressure even before any final damage awards are issued.
The Supreme Court climate lawsuit is therefore about much more than one Colorado jurisdiction. It will help determine whether climate liability remains a state-by-state courtroom strategy or becomes primarily a matter for federal policymakers, with major consequences for energy companies, local governments and the future of climate-related litigation in the United States.
