The Colorado Supreme Court signaled on Monday it may intervene in a lawsuit out of Boulder County seeking to make ExxonMobil liable for damages resulting from climate change, one of many ongoing attempts across the country to hold oil and gas producers accountable for the impacts of greenhouse gas emissions.

Boulder County and the city of Boulder originally filed suit in 2018 against ExxonMobil and Suncor Energy on the theory that the fossil fuel industry knew since the 1960s the release of carbon dioxide would lead to negative effects on the planet, but concealed that knowledge from the public.

“People, property (including County-owned property), and infrastructure within Boulder County have been and will continue to be damaged on account of climate change caused and contributed to by Defendants’ actions,” wrote the plaintiffs, specifically mentioning increased risk of drought, wildfire, and property loss from extreme weather.

The governments lodged claims under state law for public nuisance, trespass and civil conspiracy, among others. Although they did not seek to force ExxonMobil and Suncor to alter their oil and gas operations, they chose to pursue monetary damages for the past and future costs of climate change, including wildfire response, flood control and resiliency efforts.

Over the past six years, however, the litigation largely stalled. The defendants transferred the case to federal court, where it made its way up to the appellate and Supreme Court levels. Eventually, the U.S. Court of Appeals for the 10th Circuit agreed in 2022 that none of the reasons the oil and gas companies cited for being in federal court had merit, as Boulder County and the city were not trying to regulate interstate activity or undermine federal energy policy.

“The Municipalities can prevail on their claims without proving any issue of federal law because the success of those claims is grounded in traditional state-law causes of action and does not depend on any federal policy or regulation,” wrote Judge Carolyn B. McHugh.

Back in state court, District Court Judge Robert R. Gunning issued an order in June partly allowing the lawsuit to move forward. He concluded he did not have jurisdiction over Suncor, which is based in Canada, but did have jurisdiction over ExxonMobil.

Gunning reiterated what the federal courts had observed: Boulder County and the city were not trying to force a change to national climate policy, but rather were seeking compensation for local harms the oil and gas industry allegedly caused.

“This Court joins the vast majority of courts who have considered this issue” and allowed the claims to proceed, Gunning wrote, citing the Hawaii Supreme Court’s October decision in a similar case. He dismissed the plaintiffs’ consumer protection claim but otherwise green-lit the lawsuit.

ExxonMobil appealed directly to the state Supreme Court, maintaining the plaintiffs sought to hold the company liable for a “worldwide phenomenon.” Resurrecting the argument already rejected by federal courts, ExxonMobil reiterated state law could not be the vehicle for the plaintiffs’ case.

In a July 29 order, the Supreme Court ordered Gunning and the plaintiffs to respond to the company’s petition.

To date, the lawsuit out of Boulder County is one of roughly three dozen similar cases alleging consumer protection violations or climate-related damages by the fossil fuel industry. The Washington, D.C.-based Center for Climate Integrity notes Boulder County’s lawsuit was the first to be filed by landlocked jurisdictions.

San Miguel County was originally part of the litigation, but is now pursuing a separate case in Denver District Court. At the request of both sides, the trial judge paused the proceedings this month in anticipation of the Supreme Court’s intervention in the Boulder County case.

The case is ExxonMobil Corp. v. Board of County Commissioners et al.