The Supreme Court kicked off its new term Monday with tough questions about the future of Boulder’s blockbuster climate suit.
The justices are considering Suncor v. Boulder, which presents complicated questions about who should pay for the costs of climate-driven disasters.
In 2018, the city and county of Boulder sued ExxonMobil and Suncor Energy for allegedly lying about the dangers of burning fossil fuels, and leaving taxpayers to foot the bill to prepare for, and recover from, floods, wildfires, drought and more.
Ad:The Supreme Court did not delve into the substance of Boulder’s allegations. Instead, lawyers for the Trump administration and the oil companies argued that federal laws like the Clean Air Act, and Supreme Court precedent, should block Boulder’s case from proceeding.
“If Boulder’s claims are allowed to go forward, some 90,000 municipalities across the country will have the ability to make national and international energy policy by asking juries to impose catastrophic damages on selected fossil fuel producers,” said Kannon K. Shanmugam, a lawyer for the companies, in his opening statement.
Those arguments seemed to gain traction with conservative justices, including Justice Brett Kavanaugh, who questioned why prior court cases did not shut the door on Boulder’s claims.
The attorneys and justices also tangled over a question the justices posed in February, when agreeing to take up the case: whether it was ready for review by the High Court. In May 2025, the Colorado Supreme Court cleared the way for the case to go to trial. But no jury has heard the case, and no judgment has been handed down.
“A number of the discussions that you’ve had with my colleagues make me think that we’re really early in this case, that this is sort of premature from the standpoint of this court exercising its jurisdiction,” said Justice Jackson to Shanmugam.
Boulder’s lawyer, Kevin K. Russell, argued that nothing in the Clean Air Act actually stopped Boulder’s case. That’s because Boulder is not trying to regulate emissions, which is the job of the federal government. It’s instead suing over alleged deceptive practices by the oil giants.
Published research has found that decades of Exxon’s own internal communications and research revealed the acceleration of climate change, while the company simultaneously expressed doubt about the cause, or even existence, of global warming.
“[The suit] is not an effort to reduce emissions,” Russell said. “It requires [the companies] to internalize a portion of the costs of their activities by paying for some of the damage that those activities inflict.”
That point may be key for Boulder’s case to stand. But it faced some tough questions, even from the liberal justices, who asked whether suing oil companies for deceptive marketing would have the same effect as ordering companies to reduce their fossil fuel emissions.
Conspicuously absent from questioning was Justice Samuel Alito, who recused himself from the case last week. His absence could result in a split decision or even a 4-4 deadlock, which would leave Boulder’s case intact by letting last year’s Colorado Supreme Court decision stand.
The Court will not release its opinion for several months. It could uphold the Colorado Supreme Court ruling, or it could rule that the case is not yet ripe for review, both of which would allow the case to proceed.
The Court could also quash Boulder’s legal theories. A very broad ruling could hamper Boulder’s case and more than two-dozen similar “climate accountability” cases nationwide. It could also deal further blows to the climate Superfund laws passed in Vermont and New York, which requires large oil companies to pay damages to states for the impacts of burning fossil fuels.
The case has bounced around lower courts for eight years. Even if a Supreme Court ruling left a path for Boulder’s case, it would still face plenty of procedural hurdles before a jury would even hear it.
After the arguments, Russell said Boulder is determined to see the case through.
“They’ve already endured multiple years of wasted time by the fossil fuel industry making meritless efforts to get this out of state court,” Russell told reporters. “I think they understand that they have a responsibility to their constituents to not shoulder them with the full burden of climate change when there are other parties that are responsible under the law for a portion of those costs.”
All three Boulder County Commissioners were in the chambers for the argument. They said afterwards that what they want is pretty simple: for the nation’s highest court to let the case move forward.
“Faced with these rising costs, we ask, is it fair for communities to shoulder these costs alone? We believe it is not,” said Commissioner Marta Loachamin. “These companies are asking the court to help them evade responsibility. This case is not about asking the courts to solve or even to mitigate the effects of climate change. It is simply about fairness and trying to survive.”
Colorado residents urge court to let the case move forward
Outside the courthouse, several Coloradans made the trek to Washington, D.C. to see Boulder get its day in court.
Former Boulder County Commissioner Deb Gardner was waiting in the public line to try and get inside to hear the arguments. She was one of the county commissioners who voted in 2018 to launch the case against Suncor.
At first she wasn’t planning on coming, but she thought, “I was part of it from the beginning and really want to carry it on and represent the people of Boulder County, which is what we’ve been doing all along. This is what the people wanted us to do.”
She didn’t make it inside the chambers, but she was able to meet up with former commissioner Elise Jones outside the Supreme Court.
Like Gardner, Jones said it’s an important day, and not just for Colorado, “but to everybody on this planet — that we start holding Big Oil accountable for the damages that they’ve caused our communities.”
A number of survivors of the Marshall Fire spoke during a press conference in support of the suit. Jenny Singer-Rupp, from Louisville, lost her home during the fire and has spent years recovering, including navigating insurance claims and rebuilding.
“I want my children to grow up in a world where they don’t have to wonder whether the place they call home will still be there tomorrow,” she said. “I also want them to know that when something is wrong, we do not simply accept it. We stand up, we ask questions, we seek accountability, and then we fix the problems.”
She said that’s what compelled her to make the trip. She wants to know what oil companies knew about fossil fuels’ contributions to climate change, and when they knew it.
“I’m asking the Supreme Court to not block this case and to let Boulder’s case move forward. Let the evidence be heard, let survivors have their day in court,” Singer-Rupp said.
And it wasn’t just Boulder residents who rallied at the Supreme Court to support the case. Deirdre Macnab is a cattle rancher outside of Meeker on the Western Slope, while Kathryn Bedell has a herd in Mesa County. Both wanted their voices heard because their livelihoods are being impacted by climate change, whether it be drought, fires or heat.
“We’re looking for money for the communities so they can hold corporate America responsible for something they’ve known about for decades,” Macnab.
Bedell, who recently decided to give up running cattle, hopes this case will bring oil and gas to the table to come up with solutions. “We’re not looking to get rich off of anything. We want them to come to the table and solve the problems that have been created.”
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