SUPERIOR, COLO. — The U.S. Supreme Court will hear arguments in October 2026 on whether Boulder and Boulder County can pursue their climate liability lawsuit against Exxon Mobil and Suncor Energy in state court. The justices will focus on whether the lawsuit can move forward in state court, rather than ruling on the merits of the case itself.

The city of Boulder and Boulder County filed a lawsuit seeking damages from Exxon Mobil and Suncor Energy in 2018. The lawsuit accuses Exxon Mobil and Suncor Energy of misleading consumers about the effects fossil fuels would have in Colorado, including the risk of more damaging wildfires.

Exxon Mobil and Suncor Energy argue that climate change is an inherently federal issue because of the global nature of greenhouse gas emissions that state courts cannot adjudicate piecemeal. The Trump administration filed a brief in the Boulder case backing the oil companies. Exxon Mobil and Suncor Energy deny the allegations in the lawsuit.

The plaintiffs argue that the companies "intentionally misled the public about the impacts of climate change" through their advertising and marketing. The plaintiffs also argue that the companies "knowingly caused and contributed to the alteration of the climate" by producing and selling fossil fuels. The complaint mentions the “substantial and additional costs” related to increased risk of wildfires, including efforts to prevent or minimize fires and the cost of rebuilding after them.

The lawsuit does not seek to cap emissions or shut down facilities. The lawsuit does not specifically seek recompense for the Marshall Fire. The temperature in Boulder reached 104 degrees in early August 2026.

Louie Delaware is 69 years old. Louie Delaware lost his home in Louisville in the Marshall Fire. Jennifer Balch is a professor at the University of Colorado Boulder who specializes in fire ecology.

Why It Matters

The Marshall Fire occurred on Dec. 30, 2021. The Marshall Fire destroyed more than 1,000 homes.

The Marshall Fire killed two people. The Marshall Fire burned 6,000 acres between Denver and Boulder. The Marshall Fire caused an estimated $2 billion in property damage. No other wildfire in Colorado’s history has caused as much property damage as the Marshall Fire.

The Marshall Fire was ignited in two separate areas at about 11 a.m. on Dec. 30, 2021. One ignition point of the Marshall Fire was caused by a damaged power line.

One ignition point of the Marshall Fire was caused by a fire on a residential property that had not been fully extinguished. Winds of up to 100 mph spread the Marshall Fire toward Superior and Louisville.

What's New

The Supreme Court has set the argument for Monday, October 5, 2026. Marshall Fire is a Dec. 2021 wildfire in Boulder County, Colorado, USA. Boulder County is county in Colorado, United States.

Suncor Energy is Canadian energy company. The Marshall Fire caused the evacuation of 37,500 people. The Marshall Fire was neither caused by criminal negligence nor arson.

The plaintiffs argue that the companies “intentionally misled the public” about the dangers of fossil fuels while promoting their products. They further argue that the companies “knowingly caused and contributed to the alteration of Earth’s climate system” through decades of fossil fuel production and distribution. These actions, according to the complaint, have imposed significant public safety and infrastructure costs on local governments. The case hinges on jurisdictional questions about whether such claims belong in state or federal court. Legal experts say the Supreme Court’s decision could set a precedent for similar climate liability cases across the country. The outcome may influence how local governments seek accountability from energy companies for climate-related damages. The case has drawn national attention due to its potential implications for environmental law and corporate responsibility.