Supreme Court Weighs Whether Boulder Can Sue Exxon and Suncor Over Climate Change
With Justice Alito recused, a 4–4 tie is possible. The case could decide whether dozens of state-court climate suits go forward.
The Overview
The facts, straight
The Supreme Court opened its term on Oct. 5 with Suncor Energy (U.S.A.) Inc. v. County Commissioners of Boulder County (No. 25-170). The city and county of Boulder, Colorado, sued Exxon Mobil and Suncor in state court in 2018. They seek damages for local harms such as extreme heat and wildfires, which they attribute to climate change and to what they call the companies' deceptive marketing of fossil fuels. The Colorado Supreme Court allowed the case to proceed, and the companies appealed (CBS News).
The question is whether federal law, including the Constitution's structure and the Clean Air Act, bars state-law claims over harms from interstate and international greenhouse-gas emissions. The justices also asked the parties whether the Court has jurisdiction to review the Colorado ruling at this early stage.
Only eight justices heard the case because Justice Samuel Alito recused himself without explanation. A 4–4 tie would leave the Colorado decision in place, and Boulder's suit would go forward. Kannon Shanmugam argued for the companies, Principal Deputy Solicitor General Sarah Harris argued for the United States in support of the companies, and Kevin Russell argued for Boulder (Supreme Court hearing list). A decision is expected by summer 2027.
What the Left Says
The progressive and Democratic case
Boulder, environmental groups and their allies say this is an ordinary use of state tort law to address local harm.
- "Since the founding, states have had the power to provide tort remedies for injuries occurring within their borders, even when the conduct causing those injuries occurred elsewhere," Russell told the justices (CBS News).
- Boulder says the case is about deception, not about regulating emissions: "Under our deception theory, they can continue to produce as much fossil fuels as they like… when consumers are properly informed." Its brief says the case "merely asks that petitioners bear their fair share of local costs."
- Justice Elena Kagan compared the case to earlier state litigation against tobacco companies and opioid makers: "This is chapter three." Justice Ketanji Brown Jackson said review was "premature."
What the Right Says
The conservative and Republican case
The companies and the Trump administration say a single county cannot use a jury to set national and global energy policy.
- Shanmugam called the suit an "unprecedented effort" to use state law to regulate global conduct and said "a state does not have the power to regulate out-of-state conduct based solely on attenuated effects on the state." He warned that 90,000 municipalities could file similar suits and "make national and international energy policy by asking juries to impose catastrophic damages on selected fossil-fuel producers" (CBS News).
- "Interstate air pollution is an inherently federal area, and Congress hasn't authorized this suit in the Clean Air Act," Harris said. She argued that the suit "egregiously exceeds" constitutional limits on state authority.
- Justice Brett Kavanaugh pointed to decades of precedent: "We don't have to reinvent the wheel," he said, because the Court has held "multiple times" that interstate air and water pollution are governed by federal law.
Where Reality Likely Sits
Radio Purple's analysis
This is mostly a federalism case dressed as a climate case. Both sides have support in precedent. Chief Justice John Roberts raised the concern that suits like this would multiply nationwide. He also noted that state courts routinely hear mass-tort and internet cases with effects far beyond state lines, and asked what makes this one different.
The answer may depend on how the Court reads Boulder's deception theory. If the claims are really about emissions, the Court's long line of federal-pollution precedents favors the companies. If they are really consumer-deception claims, Boulder looks more like the tobacco and opioid plaintiffs. The jurisdictional question could also end the case with no ruling on the merits.
For readers, the practical stakes are clear. A ruling for the companies would likely end dozens of similar state suits and leave climate liability to Congress, which, as Boulder's lawyer noted, "stands at the ready" to legislate if it chooses. A ruling for Boulder, or a tie, sends the fight back to state courtrooms for years.
Sources & Citations
- CBS News, “Supreme Court wrestles with energy companies' bid to block major climate-change lawsuit”, October 7, 2026.
- Supreme Court of the United States, “Hearing List, October 2026 Session”.
- Supreme Court of the United States, “Oral argument transcript, No. 25-170”, October 5, 2026.
- Supreme Court Institute, Georgetown Law, “OT 2026 Highlights Report”.
- Colorado Public Radio, “Supreme Court hears Boulder climate case as Trump administration urges court to kill it”, October 5, 2026.
Positions above are attributed to the public statements and published reporting cited here. Quotations are taken from these sources; Radio Purple does not publish unattributed or invented quotes. See an error? Request a correction.