The Question of Emissions Liability Finally Heads to the Right Court

F or more than a decade, a collection of blue states, cities, and other climate plaintiffs have been asking courts across the country to decide an important question of national (and international) significance — all while doing everything they can to keep the issue away from the U.S. Supreme Court.

These plaintiffs seek to use state laws and state courts to hold energy companies liable for the worldwide effects of global emissions. That effort runs up against the basic constitutional rule that “no state can legislate for another,” and also against federal policy — most notably, the Clean Air Act — that preempts state regulation of global emissions. To evade Supreme Court review, the blue-state plaintiffs have changed legal theories, changed forums, added defendants, dismissed cases, and declined to pursue appeals. The strategy has worked. Many suits raising these theories are pending across the country, but the Supreme Court has never resolved whether the U.S. Constitution — and federal law more broadly — permits states and localities to impose liability on energy companies for global emissions.

On the first Monday in October, the Court (minus Justice Alito, who is recused) will finally have that question squarely before it in Suncor Energy v. Boulder County. And Boulder’s first request of the justices is that they decline to answer it.

Boulder argues that the Court cannot review the case because the Colorado Supreme Court’s decision resolving the question is not sufficiently “final” for Supreme Court review. As the energy companies and several friends of the court point out, that argument disregards Colorado law and how this case wended its way to the Supreme Court: as a standalone “original proceeding” the Colorado Supreme Court completely resolved. In addition, the Court has long held that some state-court rulings on federal questions may be reviewed before a case concludes, particularly where the federal issue has been finally settled below and postponing review would let it be eroded or lost. The energy companies also argue that this is such a ruling.

But Boulder’s jurisdictional objection is also the latest chapter in a much longer story. Climate plaintiffs have spent years maneuvering to obtain rulings on questions of federal law while avoiding the one court whose answers to those questions bind the whole country.

The first generation of climate suits largely involved the theory that global climate change could be reduced to the tort of nuisance, and specifically the federal common law of “interstate nuisance.” The plaintiffs filed them in federal court, and they lost across the map. California sued the automakers, only to have the case dismissed in 2007. The states’ suit against the power companies reached the Court in American Electric Power Co. v. Connecticut, where the justices held in 2011 that the Clean Air Act displaced federal common-law claims seeking abatement of carbon-dioxide emissions from fossil-fuel-fired power plants. The Alaska village of Kivalina lost a similar federal common-law nuisance claim in the Ninth Circuit the following year. The plaintiffs’ bar concluded from these defeats that they had the wrong forum, not the wrong theory.

Beginning in 2017, therefore, a second generation of suits, Boulder’s among them, pleaded only state-law torts and were filed in state courts. When the defendants removed the cases to federal court and argued that claims about worldwide emissions arise under federal law whatever label they wear, the plaintiffs fought successfully to send the cases back to state court. The Supreme Court intervened once, in BP p.l.c. v. Mayor and City Council of Baltimore, in 2021, to hold that federal appellate courts reviewing those remand orders had to consider all of the defendants’ asserted grounds for removal rather than just one. That made no practical difference. The cases returned to state court anyway.

A federal appellate court has reached the merits of a second-generation suit exactly once, and only because New York City had chosen to file in federal court. In City of New York v. Chevron Corp., the Second Circuit held in 2021 that federal law, not state law, governed the city’s claims over global greenhouse-gas emissions and that the claims could not proceed. The city did not seek Supreme Court review, lest that ruling become the law of the land. Three weeks later, the city filed a restyled complaint in state court.

The network of these plaintiffs has not been shy about any of this. California’s attorney general, Rob Bonta, has said publicly that his state waited five years to sue until it was confident the defendants could no longer remove to federal court, because the choice of forum was “outcome determinative.” Complaints now arrive with paragraphs disclaiming any federal question. Multnomah County, Ore., named small local fuel retailers as defendants, a move that prevented diversity jurisdiction and helped keep the case in state court. When plaintiffs in Washington and California pleaded their way into federal court by accident, they dismissed their own cases rather than stay. When Baltimore lost in Maryland’s highest court this year, it did not seek certiorari. The climate plaintiffs will appear before any court in America except one.

The strategy has now reached that court in the form of Boulder’s jurisdictional objection. Boulder says the companies have come to “the wrong forum at the wrong time with the wrong arguments.” But it is the climate plaintiffs who have insisted on the wrong forum for going on 15 years.

It is no small irony that Boulder takes refuge in the set of jurisdictional rules that Congress enacted to keep the nations’ two court systems — state and federal — in their proper relation to one another. By Boulder’s own telling, the purpose of the jurisdictional rules it invokes is to “minimiz[e] potential conflicts” between state and federal governments.

Boulder’s lawsuit turns those rules inside out. Its retreat to jurisdictional boundary-drawing only highlights Boulder’s disregard of constitutional boundaries. Congress also enacted the Clean Air Act, which conflicts with and preempts these suits. And just as the Constitution forbids a state’s courts from reaching into any domain it wants, the Constitution forbids a state’s legislature from regulating any place it wants.

Boulder’s lawsuit would make a Colorado jury the arbiter of energy production in Texas, refining in Louisiana, and combustion on other continents, and it would do so under the law of Colorado. That is an encroachment on the federal domain of the most ambitious kind, an attempt by one county to set national and international energy policy through the law of nuisance. Yet Boulder defends this encroachment by invoking, at every turn, the procedural rules designed to prevent it. It wields the allocation of power between state and federal courts as a sword against the allocation of power between state and federal governments. The forms of federalism are being deployed to dismantle its substance.

Whether federal law governs the tort consequences of global emissions is a question the Court itself left open 15 years ago, and only the Court can resolve it. For over ten years, the plaintiffs have run a game of cat-and-mouse through the state courts, changing labels, adding defendants, dismissing and refiling, always a step ahead of federal review. It would be a shame if the Court fell for the latest gambit and dismissed the case on specious jurisdictional grounds, leaving the states free to go on regulating the nation’s energy supply from county courthouses while the one court with authority to stop them looked politely away. The mouse has had its decade. The Court should end the game.