The U.S. Supreme Court heard oral arguments today in a lawsuit where the City of Boulder and Boulder County seek to hold ExxonMobil and Suncor Energy responsible for climate-related damages. The central legal question is whether federal law shields the companies from liability in state courts or whether Colorado law allows the communities to proceed.
The lawsuit, originally filed in April 2018, alleges that the companies knowingly contributed to climate change while concealing the dangers of their products. Boulder County and the City of Boulder argue the companies should pay for local climate-related harms, including from wildfires, flooding, drought, extreme heat, and air quality degradation.
A Colorado state court ruled in May 2025 that federal law does not preempt the lawsuit, allowing it to proceed. But the companies appealed to the U.S. Supreme Court, claiming that federal law shields them from all accountability in state courts. The high court is considering whether to allow the case to move forward.
Oral argument recordings are available online. The Supreme Court's decision could determine whether states retain the power to hold companies liable for out-of-state conduct that causes in-state harmโa question with implications for climate litigation nationwide.