Supreme Court poised to define limits of state climate lawsuits under the Tenth Amendment

The Supreme Court is set to consider Suncor Energy v. County Commissioners of Boulder, a dispute that could restrict states from pursuing climate-change nuisance claims against out-of-state fossil-fuel producers. Petitioners maintain that only the federal government may regulate interstate greenhouse-gas emissions, framing the issue as vertical preemption. The analysis highlights a less-examined horizontal federalism angle, arguing that the Tenth Amendment protects states from one another’s legislative reach.

Historical references to the Privileges and Immunities Clause, Commerce Clause, and the Founders’ view of state sovereignty support this view. The author warns that allowing Boulder’s suit would let one state dictate policy for others, undermining the constitutional balance among states.