Uninvited DOJ Brief Urges Supreme Court to Take Climate Case (1)

The Trump administration is urging the US Supreme Court to take up oil companies’ petition to review a Colorado climate lawsuit, according to an unexpected amicus brief filed Thursday.

A Colorado high court decision to let Boulder’s climate lawsuit proceed closer to trial requires review “twice over,” the Justice Department wrote in an unannounced brief.

The Colorado Supreme Court ruled in May that the climate fraud and nuisance suit brought by Boulder County and the City of Boulder could move forward towards trial, joining Hawaii and other municipalities that have also advanced their climate suits in local courts.

But that Colorado court’s decision is “manifestly wrong,” and could open the floodgates for other suits that should be preempted by federal law, according to the government brief.

“If, as the Colorado Supreme Court held, suits like this one may go forward, energy companies across the globe will be subject not only to billions of dollars in damages, but also to a multiplicity of rules governing their conduct in any given location, as one city after another seeks to hold the companies liable for fossil-fuel activities anywhere in the world,” the DOJ wrote.

Suncor Energy and Exxon Mobil Corp. petitioned the US Supreme Court in August, asking justices to take up the question of whether federal law preempts state-based lawsuits seeking relief for climate change damages. The county and city of Boulder had sued the companies in state court seeking damages for the companies’ alleged role in producing and selling fossil fuels that contributed to climate change.

Judges are increasingly skeptical of these types of cases once they reach merits arguments in local jurisdictions. Courts in New York, Delaware, Maryland, and other states have dismissed similar suits. Climate tort plaintiffs have seen early success in Colorado, Hawaii, Massachusetts, and the District of Columbia.

Paul, Weiss, Rifkind, Wharton & Garrison LLP represents energy companies, and the Law Office of Marco B. Simons represents Boulder.

The case is Suncor Energy USA Inc. v. Cty. Comm’rs of Boulder Cty., U.S., No. 25-170, Amicus Brief 9/11/25.