Deirdre Macnab was reading her local newspaper this spring when she learned that Rio Blanco County, where she lives in northwest Colorado, had taken the side of oil companies in a major lawsuit before the Supreme Court. Suncor and Exxon Mobil were trying to get out of standing trial — the city and county of Boulder had sued them, seeking damages for the rising costs of adapting to heat waves, wildfires, and floods.
After ranching for a decade, Macnab had seen those costs firsthand. During one of the worst fires in Colorado history last year, 60 of her neighbor’s cows burned to death. Record heat and drought this year parched the land so thoroughly, ranchers had to pay thousands of dollars to haul in feed and water for their animals. Some ranchers, headed toward bankruptcy, had to sell part of their herds or put their land up for sale.
“It really disturbed me that the county was taking sides,” Macnab said, “and in particular, supporting oil companies whose operations, we now know, are putting the human population and wildlife, livestock, everything, at risk.” Rio Blanco County spent thousands of taxpayer dollars in legal fees to join the brief alongside other Colorado counties where the oil industry has a large presence.
Macnab rallied ranchers around Colorado to join her in urging the Supreme Court to side with Boulder. They wrote that local governments can’t keep absorbing the increasing costs from worsening heat, drought, fires, and flooding and still provide the resources — disaster relief, grants, infrastructure repairs — to keep ranchers in business. The oil companies argue that federal law not only protects them from needing to defend their actions in state courts, but also shields them from being liable for damages.
The Supreme Court is set to hear oral arguments in the case on Monday. The court’s decision could have huge ramifications for efforts to hold companies accountable for deceiving the public about the dangers of burning fossil fuels — and the larger question of who pays for the costs of adapting to a hotter world. Oil majors have pulled out all the stops to stymie the dozens of climate lawsuits that local and state governments have brought against them, with billions and billions of dollars on the line. With a conservative-dominated Supreme Court and the Trump administration’s Department of Justice as a powerful ally, oil companies saw their chance to stop these suits, said Alejandro Camacho, a professor at UCLA School of Law.
That calculus changed slightly this week when Supreme Court Justice Samuel Alito, a strong conservative with financial holdings in oil companies, recused himself from the case. His withdrawal makes it harder for oil companies to get at least five justices — a majority of the court — on their side.
The city and county of Boulder, Colorado, originally sued Suncor and Exxon Mobil in 2018. The lawsuit slowly wound its way through the court system. Oil companies tried to dismiss it or move it to federal court, a more industry-friendly venue, but Boulder won at every stage. In May 2025, the Colorado Supreme Court ruled that the case should proceed in state courts.
Much of the support for Boulder and the oil companies falls along familiar, partisan lines. Republican states and business associations tend to side with the oil companies; Democratic states and environmental advocates typically back Boulder. A watchdog organization found that 25 of the 38 briefs filed to the Supreme Court in support of Exxon and Suncor were written by groups with financial ties to the fossil fuel industry or foundations opposing climate science and regulation. But Colorado ranchers aren’t the only surprising source of support for Boulder’s case — some conservative thinkers are challenging oil companies’ arguments.
To understand why, it helps to know that the case before the Supreme Court isn’t really about the substance of the lawsuit: if oil companies should pay damages for climate change. The first question is whether the Supreme Court can take the unusual move of stepping in before the case has gone to trial in state court. If the justices decide that they can, then they’ll consider oil companies’ arguments. Suncor and Exxon’s lawyers argue that Boulder’s suit is essentially a backdoor attempt to regulate emissions through state courts. They also say that the Clean Air Act and broader constitutional limits on state power should prevent Boulder’s claims from proceeding.
“If someone has harmed you, you should be able to go to court and make the case that they harmed you and that they need to pay you for it,” Camacho said. “It’s a centuries-old common law principle. And these companies are basically trying to say, ‘You shouldn’t be able make the case in court.’”
Some conservative legal scholars argue that there’s nothing in the federal law or the Constitution that would prevent the lawsuit from moving forward in state court. That includes Jonathan Adler, an environmental law professor at William & Mary Law School. Two former heads of the EPA under Republican presidents, Christine Todd Whitman and William Reilly, are other prominent proponents of that argument.
The oil companies appear to have recognized that their arguments about the Clean Air Act aren’t very strong, Adler said, because they’ve moved away from them over time, toward other arguments about the limits of state power. In his view, courts generally shouldn’t override claims brought under state law “unless there is a clear basis for doing so.” Adler sees why some conservatives argue that the litigation in state courts is an improper way to drive climate policy, but he thinks it’s possible that skepticism about the merits of the lawsuit might have influenced some of their views on the narrower questions before the court.
Some Republican-dominated jurisdictions have also found themselves challenging oil companies. Coastal parishes in Louisiana are suing Chevron and other oil majors, seeking compensation for restoring coastal lands. “There are going to be conservative communities, or predominantly conservative communities, who see that they are being forced to pay millions of dollars to protect their towns because of the actions of fossil fuel companies,” Camacho said.
Colorado ranchers, not exactly known for their liberal views, are left with few options for dealing with the environmental changes that are bankrupting them. Macnab said she hopes the Supreme Court sends Boulder’s case back to state court where it belongs, so that oil companies will be forced to face accountability.
“Until they’re held responsible for the consequences that they have known about for decades, they are not going to be part of the solution,” Macnab said. “They need to be brought to the table, because humankind and our food production is what’s at stake.”
