Supreme Court opens its term with Exxon and Suncor's bid to end climate suits, but may never reach the merits

The Supreme Court starts its new term on Monday with a case the oil industry has been trying to get in front of the justices for years. Suncor Energy (U.S.A.) Inc. v. Commissioners of Boulder County, docket 25-170, is the first argument on the Court's October calendar, at 10 a.m. Eastern. Exxon Mobil and Suncor are asking the Court to rule that federal law blocks state-law suits seeking money for local climate damage.

What the case is about

Boulder County and the City of Boulder sued Suncor and Exxon in Colorado state court in April 2018, alleging the companies contributed to climate change while concealing the risks and misleading the public. The city says the suit "is not about regulating emissions or stopping fossil fuel production"; it seeks compensation for costs such as heat, wildfire and drought. In May 2025 the Colorado Supreme Court let it proceed, ruling 5 to 2 that federal law did not preempt the claims.

The companies argue the Clean Air Act and the Constitution leave interstate and international emissions to federal law, so no state can impose liability for them, according to a Congressional Research Service primer published September 30. The Justice Department has filed a brief on the companies' side. CRS counts nearly 200 members of Congress and more than 40 states on amicus briefs for one side or the other.

The part most previews skip: the Court may not decide the big question

When the justices agreed to hear the case, they added a second question: whether they have jurisdiction at all. Boulder argues the Colorado ruling is not a final judgment, since the case has not gone to trial, and that the companies have suffered no injury yet that would give them standing to appeal.

If enough justices agree, CRS notes, the Court would dismiss the case "as improvidently granted." That would leave the Colorado decision standing and send Boulder's suit back to the trial court, with the preemption question unresolved. So the market's obvious framing, a yes-or-no ruling on climate liability, is only one of the possible outcomes. Watching which question the justices spend Monday on is the quickest read on which way it is heading.

History is also on the plaintiffs' side so far. Every federal appeals court that looked at where these suits belong, eight circuits in all, sent them to state court, and the Supreme Court turned down at least eight earlier petitions from oil companies, including a previous one from Suncor in this same case, CRS records. Those petitions were about which court should hear the suits; this time the companies are asking whether the suits can exist at all.

Why it matters beyond Boulder

Boulder is one of dozens of similar suits. The CRS report lists pending cases brought by California, Delaware, Hawaii, Maine, Minnesota, New Jersey and Rhode Island, and by Honolulu, Maui, Chicago, Hoboken, Multnomah County in Oregon and King County in Washington, among others. A ruling for the companies on the merits would likely end most of them. A ruling for Boulder, or a dismissal, would keep them all moving.

Even a win for the companies may not be total. Boulder argues that federal preemption, if it applies, covers only out-of-state emissions, leaving claims tied to in-state emissions intact. Congress could also settle it: identical House and Senate bills introduced in April, the Stop Climate Shakedowns Act (H.R. 8330 and S. 4340), would bar such suits against energy companies outright.

Where the stocks stand

Neither stock has been held back by the litigation this year. Exxon closed Friday at $164.01, up from $120.53 on December 29, about 36%, and Suncor at $69.56, up from $43.73, about 59%, according to Nasdaq data. Oil above $90 has done most of that work; see our story on Sunday's OPEC+ decision. Exxon's market value is about $674 billion.

Oral argument rarely settles a case, and the Court typically issues its biggest opinions near the end of the term in June. The audio is livestreamed on the Court's website.

Sources: Supreme Court argument calendar, Congressional Research Service, City of Boulder, Seeking Alpha, Nasdaq market data. Calculations are ours. This is market information, not investment advice.