Two Colorado communities are asking the Supreme Court to allow them to continue suing fossil fuel producers for climate change, saying the lawsuit is an “exercise of traditional state power.”
In a brief filed Monday, the city and county of Boulder outlined their arguments in Suncor v. Boulder, a blockbuster climate case the court will take up in the fall that could derail nearly two dozen similar lawsuits against the oil and gas industry.
The governments are asking the court to reject the industry’s bid to overturn a 2025 Colorado Supreme Court decision that allowed the lawsuit to proceed in state court.
Exxon, Suncor and others assert that using state tort law to address global climate change is incompatible with the Constitution.
But the local governments say that argument would “cast a shadow over laws long understood to represent valid exercises of the states’ constitutionally reserved powers.” The quote is from a 2023 Supreme Court decision that rejected a challenge to a California law setting spacing requirements for sows.
“Since the Founding, courts have applied state law to such cases, including to remedy environmental harms,” the governments wrote in the brief.
The city and county of Boulder sued major oil producers in 2018, accusing them of deceiving the public about the danger of burning fossil fuels. The lawsuit seeks compensation for the public costs of rising tides and intensifying storms.
In their brief, the Colorado governments acknowledged that they may face challenges in proving a cause and effect between fossil fuels and local climate change impacts.
But “that is no reason to take the case out of state hands,” they added. “Nor does the global nature of climate alteration disable states from redressing in-state harms.”
The brief called oil and gas companies “impatient,” noting that Congress is considering legislation to provide the industry immunity from climate lawsuits.
“Unwilling to let either the federal legislative or the state judicial process play out, they have run to this Court at the case’s outset,” the governments wrote.
The companies have argued the Clean Air Act preempts the lawsuits by creating a system to regulate air quality. The lawsuits, they assert, “undermine that scheme by subverting the primacy of federal regulation.”
But the governments said the Act regulates point-source emissions, not the production, sale or marketing of products.
“It certainly does not charge the EPA with regulating deceptive marketing of fossil fuels,” the governments wrote.
The U.S. Supreme Court also asked each side to consider whether the court has the authority to hear the case, which has not yet reached a final resolution in the Colorado courts. Some analysts suggested the question could signal that the justices want to wait until a final trial and exhaustion of state appeals.
The city and county of Boulder argued the court can only review state courts’ final judgments, “not interlocutory rulings like this one.”
The governments noted the Colorado Supreme Court “merely declined to dismiss” the lawsuit and that the governments “must still prove their claims and overcome numerous other defenses.”
The companies in May argued that the Supreme Court has jurisdiction because the Colorado decision will force the companies “to incur monetary costs as a result of being forced to continue defending these lawsuits.”
But the governments said “continued litigation costs are a byproduct of the suit itself, not a cognizable injury.”
