Facts of the Case
Boulder County and the City of Boulder sued Exxon Mobil and three Suncor Energy entities under Colorado common law—asserting nuisance, trespass, unjust enrichment, and civil conspiracy claims—seeking monetary damages for climate-change harms such as flooding, wildfire risk, and infrastructure damage allegedly caused by the companies' production and promotion of fossil fuels. The defendants argue the claims are precluded by federal law, including the Clean Air Act, federal common law of interstate pollution, and the federal foreign affairs power. The Boulder County District Court denied dismissal on preemption grounds, and the Colorado Supreme Court ruled for Boulder in May 2025.
Questions
Does the Court have statutory and Article III jurisdiction to hear this case?
Does federal law preclude state-law claims seeking relief for injuries allegedly caused by the effects of interstate and international greenhouse-gas emissions on the global climate?