The justices heard oral arguments Monday in Suncor Energy Inc. v. County Commissioners of Boulder County.
Boulder is seeking billions of dollars from companies like Suncor and ExxonMobil, arguing that fossil fuel emissions drive costly local disasters like floods and wildfires — including the devastating 2021 Marshall Fire, which was the most costly wildfire in Colorado history.
Boulder County, Colorado, says oil and gas companies contributed to climate change and should pay for damage the county has suffered. The companies argue that federal law, not state courts, should decide these climate-related claims, so the Supreme Court will decide whether Boulder can pursue its lawsuit under state law.
Kevin Mooney, an investigative reporter for free market think tanks, believes the energy industry has a strong case regarding federal preemption under the Clean Air Act, a comprehensive U.S. federal law passed in 1970 and later amended to protect human health and the environment from air pollution.
"The energy companies are arguing, I think with good credibility, that there's federal preemption, that the Clean Air Act really is operative here and supersedes anything the states might do," he says.
Mooney, who has authored a book that critiques modern climate activism, climate policy and the political movement surrounding it, notes that a win for Boulder could create a slippery slope, allowing blue-state policies to override the will of voters in pro-energy states.
"If somehow the plaintiffs prevail, and somehow a municipality or a city or a state suddenly has the power and influence to superimpose their policies across the whole country, then all of a sudden your votes for your state lawmakers don't matter," he explains.
In the past, the federal district court remanded the case to Colorado state court, the 10th U.S. Circuit Court of Appeals affirmed that decision, and the Boulder County District Court later rejected the companies' arguments that federal law preempted Boulder's claims; the Colorado Supreme Court upheld that ruling in 2025.
Justice Samuel Alito is recused from the case due to stock ownership, raising the possibility of a tie vote —which would leave a lower court ruling in favor of Boulder intact.
A decision is expected in the coming months.
