One atmosphere, 50 courts — what could go wrong?

The Supreme Court opened its new term Monday with one of the most consequential climate cases in years. The justices do not have to decide whether climate change is real or whether carbon dioxide warms the planet. They face a more basic question: Who pays the tab?

In Suncor Energy v. Boulder County, Boulder County and the city of Boulder want ExxonMobil and Suncor to pay under Colorado law for local costs they attribute to global warming, while also alleging deceptive marketing. The Colorado Supreme Court allowed the claims to proceed.

A Colorado jury cannot set national climate policy, but a patchwork of state tort verdicts could begin to approximate one.

The U.S. Supreme Court is considering whether federal law precludes them and whether it has jurisdiction to