Supreme Court to Hear Case on Cities Suing Oil Companies Over Climate Change

Ruling could reshape legal landscape for climate accountability nationwide, with billions in damages at stake.

Published on Feb. 23, 2026

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The Supreme Court has agreed to hear a case that could determine whether state and local governments can hold fossil fuel companies legally responsible for climate change-related harms. The case was originally filed in 2018 by Boulder County, San Miguel County, and the City of Boulder against Suncor and ExxonMobil, alleging the companies knowingly sold fossil fuels that would cause measurable harm to Colorado. The outcome could open the door for communities across the country to pursue similar accountability measures or effectively shut down state-level climate litigation nationwide.

Why it matters

The case has major implications for the future of local climate accountability, with dozens of cities and municipalities currently pursuing similar lawsuits against oil and gas companies collectively seeking billions in damages. A ruling in favor of the oil companies could effectively shield them from state-level liability, while a ruling for Boulder could empower communities to hold fossil fuel companies responsible for climate change impacts.

The details

The Supreme Court announced it will review last year's Colorado Supreme Court ruling that allowed Boulder and Boulder County's climate accountability case to proceed against Suncor and ExxonMobil. The oil companies argued federal law shields them from state-level accountability, but the Colorado court ruled federal law did not preempt Boulder's claims. The Trump administration later urged the Supreme Court to accept the case, even though it was not a direct party.

  • The original lawsuit was filed in April 2018 by Boulder County, San Miguel County, and the City of Boulder.
  • The Colorado Supreme Court ruled in May 2025 that the case could proceed under state law.
  • The Supreme Court is expected to hear oral arguments in the current term, with a decision likely by late June 2026.

The players

Suncor

An oil and gas company that is a defendant in the climate accountability lawsuit.

ExxonMobil

An oil and gas company that is a defendant in the climate accountability lawsuit.

Boulder County

A plaintiff in the climate accountability lawsuit against Suncor and ExxonMobil.

City of Boulder

A plaintiff in the climate accountability lawsuit against Suncor and ExxonMobil.

San Miguel County

A plaintiff in the climate accountability lawsuit against Suncor and ExxonMobil, with its case currently proceeding separately in Denver district court.

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What they’re saying

“Boulder, Colorado, cannot make energy policy for the entire country.”

— ExxonMobil and Suncor (Supreme Court petition)

“The oil companies have tried every avenue to delay our climate accountability case or move it to an out-of-state court system. As everyone continues to face rising costs that put budgets under pressure, we must hold oil companies accountable for the significant harm they've caused our communities.”

— Ashley Stolzmann, Boulder County Commissioner (Press release)

“Local communities are living with the mounting costs of climate change. The Supreme Court should affirm Colorado's right to hold these companies accountable for the harm they have caused in Colorado.”

— Aaron Brockett, City of Boulder Mayor (Press release)

What’s next

The Supreme Court is expected to hear oral arguments in the Boulder case during its current term, with a decision likely by late June 2026. That ruling will determine whether Boulder's lawsuit can continue in state court and is expected to set binding precedent for dozens of similar climate cases nationwide.

The takeaway

This case has major implications for the future of local climate accountability, with billions in potential damages and the ability of communities across the country to hold fossil fuel companies responsible for climate change impacts hanging in the balance. The Supreme Court's decision could reshape the legal landscape for climate litigation for years to come.