Supreme Court weighs whether Boulder can make oil companies pay for climate change

The Supreme Court on Monday takes up one of the biggest environmental cases in years: whether a local government can use state law to make oil companies pay for the costs of climate change.

The case, Suncor Energy v. Commissioners of Boulder County, is the first argued on the court's new term, according to the Supreme Court's official argument calendar. The court convenes at 10 a.m. Eastern.

## What Boulder is asking for

The city and county of Boulder, Colorado, sued Exxon Mobil and Suncor Energy in 2018. They allege the companies' production and "allegedly deceptive marketing" of fossil fuels led to "unchecked" use, according to CBS News. Boulder says that has forced local taxpayers to deal with extreme heat, larger wildfires and damage to ecosystems.

Boulder wants money for infrastructure repairs, environmental damage, emergency management and public health costs, Reuters reported. The suit relies on state-law claims, the kind of claims usually heard in state court.

"Boulder is already experiencing the effects of a rapidly warming climate," Jonathan Koehn, the city's climate initiatives director, told PBS News when the court agreed to hear the case.

## What the oil companies argue

Exxon and Suncor say federal law overrides Boulder's claims. They argue that the Clean Air Act governs greenhouse gas emissions and that states and cities cannot use their own laws to regulate a global problem, according to CBS News.

If Boulder's suit goes forward, the companies warn, "all fifty States" and countless local governments could set "conflicting climate policies." Company lawyers called the use of state law to address global climate change "a serious threat to one of our Nation's most critical sectors," PBS reported.

The Trump administration's Justice Department sided with the companies. It argued that suits like Boulder's create "needless diplomatic friction" and intrude on federal authority over foreign affairs, according to CBS. Twenty-six states also filed in support of the companies.

## How it got here

Colorado's Supreme Court refused to dismiss the case in May 2025, Reuters reported, rejecting the argument that federal law blocks it. The companies then appealed to the U.S. Supreme Court, which agreed in February to hear it.

The court has previously turned down a similar request from oil companies to throw out a climate lawsuit filed by Honolulu, according to Reuters.

## Only eight justices

Justice Samuel Alito recused himself late last month. The court did not explain why, according to Colorado Public Radio, which reported that Alito holds investments in ConocoPhillips and Phillips 66.

That leaves eight justices. If they split 4-4, the Colorado Supreme Court's ruling for Boulder would stand, CBS News reported.

## Why it matters beyond Colorado

Boulder's case is one of dozens of climate lawsuits filed by states, cities and counties against fossil fuel companies, Reuters reported. Colorado Public Radio counted about two dozen moving through state courts. Others have been brought by places including California, Hawaii and New Jersey, according to PBS.

A ruling for the companies could end many of those cases. A ruling for Boulder would let them proceed toward trials, where the governments would still have to prove their claims.

## What happens next

The justices hear the case Monday morning. A decision is expected by summer 2027, according to CBS News. Until then, Boulder's lawsuit and similar cases nationwide stay in limbo.

For young Americans, the case could shape who pays for the costs of hotter summers, bigger wildfires and storm damage in the decades ahead: taxpayers or the companies that sell fossil fuels.