Local governments want the Supreme Court to let state lawsuits force selected energy companies to pay for climate harms, a path critics call an indirect carbon tax that bypasses Congress.
When the Supreme Court opens its new term, the justices will take up Suncor Energy v. Boulder County, a fight over whether cities and counties can use state liability law to extract payments from companies for harms tied to global climate change.
Boulder County and the City of Boulder sued Suncor Energy and Exxon Mobil, contending the firms should pay for local climate-related harms because of their production, promotion, and sale of fossil fuels. The case lands amid more than three dozen similar climate suits pending across the country, with governments targeting anywhere from one company to dozens.
Manufacturers are watching closely. The legal theory on display does not stop at oil and gas; governments and advocacy groups have already pursued manufacturers over plastic waste and other products. Uncertainty of that kind can discourage investment, constrain innovation, threaten jobs, and raise costs for consumers.
In 2011’s American Electric Power Co. v. Connecticut, the Supreme Court majority explained that greenhouse gas emissions are inherently interstate and international, and that claims involving them are governed by federal law. The Court cautioned that “borrowing the law of a particular state would be inappropriate.”
Congress and federal agencies, not judges, have the tools to weigh the competing scientific, economic, and policy considerations, the Court stressed then. The Obama administration underscored a related problem in that case: climate change involves such broad categories of potential plaintiffs and defendants that no obvious limiting principle exists for deciding who should be liable. Governments can select “a handful of defendants from among an almost limitless array of entities” associated with greenhouse gas emissions.
That same selection problem sits at the center of the Boulder litigation. Greenhouse gas emissions come from countless sources across the globe for generations. State-by-state damage theories invite a patchwork of suits that treat national and international activity as if it were a local tort.
One lawyer representing Boulder said part of the intended effect is to “raise the price” of oil, gas, and other forms of energy. Another attorney associated with the litigation described the liability sought as “an indirect carbon tax,” explaining that the cost would ultimately be passed on to consumers.
Those admissions matter. Carbon penalties and energy price policy belong in the federal policymaking process, where elected officials face voters and where trade-offs are debated in public. They do not belong in a model where one county’s complaint sets the effective rate for the rest of the country.
High-profile Supreme Court fights regularly draw intense scrutiny of who sits and who steps aside, as when Alito recused from a major climate suit days before arguments. The institutional stakes here run just as high for the separation of powers.
Three amicus briefs supporting the petitioners press the deeper structural issue. National Review examined filings from Save Our States, Consumers’ Research, and Tennessee Attorney General Jonathan Skrmetti arguing that Boulder’s approach collides with core limits on one state’s power to regulate conduct beyond its borders.
The Consumers’ Research brief roots territorial jurisdiction in the law of nations and early authorities, including Vattel and Justice Story. Story’s formulation is blunt:
"no state or nation can, by its laws, directly affect, or bind property out of its own territory."
Save Our States emphasizes historical practice that extraterritorial regulation was unthinkable at the Founding and points to cases such as The Schooner Exchange and United States v. Bevans. Chief Justice Marshall put the principle simply in Bevans in 1818:
"the jurisdiction of a state is co-extensive with its territory."
Those citations are not academic decoration. If Colorado tort law can be used to police production and sales decisions made far outside Colorado, coequal state sovereignty becomes optional. One locality’s preferred energy policy hardens into a national rule without a statute, a regulation, or a vote in Congress.
The Court has faced repeated tests of how far state power can stretch before federal review steps in, including fights over Missouri’s redrawn congressional map returning for a third look while ballots were already being cast. Climate torts present a different subject matter with the same structural risk: state actors using local process to set rules that bind the whole country.
America’s manufacturers have invested in emissions-reducing and efficiency technologies while watching governments expand the same litigation playbook beyond fossil fuels. Plastic waste suits and product-focused claims already show how quickly the defendant list can grow once courts accept the basic theory.
Legal uncertainty of that scale does not stay confined to corporate balance sheets. It shapes where capital goes, which projects get built, and what households ultimately pay. When liability is untethered from clear federal limits, the safe move for many firms is delay, and delay is a cost consumers absorb.
Other recent Supreme Court clashes have turned on whether the justices put executive or state action ahead of competing claims at the ballot box, including Justice Jackson’s complaint that the Court put the Trump administration ahead of voters on citizenship checks. The Boulder docket asks a parallel question about who writes national policy: Congress and federal agencies, or creative state-court plaintiffs.
State map disputes have produced their own back-and-forth with the justices, from orders that blocked Missouri’s GOP-drawn congressional map a second time to later bids for emergency relief. Climate liability suits are the energy-policy version of the same temptation, win in court what could not be locked in through the national political process.
The 2011 American Electric Power ruling did not pretend climate policy is simple. It said the opposite: the choices are large, the actors are many, and the proper tools sit with Congress and federal agencies. Boulder’s theory tests whether that line still holds when plaintiffs reframe the same emissions as a state-law nuisance or similar claim and pick a short list of deep-pocket defendants.
If the Court blesses that model, the practical result is a shifting maze of state and local suits rather than a coherent national standard. Companies face different exposure depending on which county files first. Voters lose a clear line of accountability for the price of energy. And manufacturers outside the oil patch learn that today’s climate tort can become tomorrow’s product suit.
Missouri’s attorney general has pressed the justices to restore a state map on a tight election calendar, another reminder that Supreme Court timing can decide real-world stakes before the politics settle. Suncor presents the energy-sector version of that urgency: clarity on who may set nationwide climate costs, and by what authority.
The Constitution gives states ample room to govern inside their own borders. It does not give them a free warrant to conscript the rest of the country into a carbon price invented in a county courthouse.
