On October 5th, 2026, the U.S. Supreme Court will open its term with Suncor Energy v. County Commissioners of Boulder County. It will be one of the first climate damages cases to reach the nation’s highest court. The justices will decide whether cases like these can go forward at all, and whether environmental activists can set U.S. climate policy from the courtroom and financially penalize global companies for their products. Ultimately, those costs would land on consumers at a time when household budgets are already stretched.
The case began in 2018, when Boulder County and the City of Boulder, Colorado, sued to force Suncor and ExxonMobil to pay for the alleged local harms of the companies’ global greenhouse gas emissions. In May 2025, the Colorado Supreme Court ruled that the federal Clean Air Act does not block these claims, reasoning that Boulder is simply trying to recoup damages—not regulate emissions.
The Suncor case alleges public nuisance, trespass, and unjust enrichment under Colorado tort law. The logic goes as follows: Oil and gas companies have contributed to climate change, which creates tangible harms that the companies should pay for; climate change’s effects amount to an unwanted physical intrusion onto property in the county; and the companies profited unfairly from the gains by knowing about climate harms and not warning anyone.
This is a legal stretch, to say the least, because public nuisance lawsuits have historically been restricted to local, provable harms, like blocked roads or fouled wells. Others have said more plainly that the strategy is an indirect way of getting changes that would never have passed through Congress. David Bookbinder, formerly a counsel of record representing Boulder County, has said that, “Essentially, the tort liability is an indirect carbon tax. You sue an oil company, an oil company is liable, the oil company then passes that liability on to the people who are buying its products.”
A Pacific Research Institute (PRI) analysis found that for every $100 billion in potential judgments in climate public-nuisance cases, gas prices could rise 31 cents per gallon and cost households an additional $326 per year. California’s attorney general has admitted that one goal is to make oil and gas “more expensive” and disincentivize its use. If the justices let Boulder’s theory stand, household budgets would be hit directly by higher gas prices, as well as indirectly through higher prices of goods that take energy as an input—which is almost all of them.
The Supreme Court’s decision will be closely watched, as more than 30 similar lawsuits have been filed by municipalities and state governments across the U.S., including New Jersey, Minnesota, Rhode Island, and California. Producers cannot plan or invest around fifty states’ conflicting and unbounded liability regimes—but if Boulder’s theory stands, that’s exactly what will happen, with the costs being passed on to consumers. Energy policy this consequential belongs with Congress, not one Colorado county.