The U.S. Supreme Court will hear oral arguments Monday in a lawsuit filed by Boulder County and the City of Boulder against ExxonMobil and Suncor Energy, the first case of the fall 2026 Supreme Court term.
Arguments are scheduled to begin at 10 a.m. Eastern time (8 a.m. Mountain Time). Boulder County and the City will be represented by Kevin Russell of Russell & Woofter LLC.
The case seeks to hold the oil companies liable for damages to Boulder resulting from what the plaintiffs allege are harms from the companies knowingly contributing to harmful alteration of the climate while concealing the dangers of their products and misleading the public. Boulder County and the City of Boulder originally sued the companies in April 2018.
The lawsuit has prevailed at every stage and survived repeated attempts by the companies to move or dismiss it. The U.S. Supreme Court is reviewing a May 2025 Colorado Supreme Court ruling that allowed the case to proceed. The Colorado Supreme Court concluded that federal law did not preempt Boulder's claims and that those claims could proceed under state law.
The companies argue that federal law shields them from all accountability for harms from altering the climate, and that no state law can apply even where they cause harm in Colorado. The Supreme Court is considering the companies' bid for immunity.
Colorado is already experiencing climate-related trends such as extreme heat, wildfires, drought, and poor air quality, all of which create significant public costs. The lawsuit seeks to ensure fossil fuel companies pay their fair share of the rising costs of climate impacts on local communities.