The Supreme Court justices explored on Monday whether municipalities can hold oil companies responsible for climate-related damages, and various legal experts are weighing in on the matter.
During oral arguments for the case Suncor Energy v. Board of County Commissioners of Boulder County, the nine justices appeared to have differing opinions. The City of Boulder and other Colorado governments argue that the companies should be liable for claimed local climate impacts. In contrast, energy firms Suncor and ExxonMobil argue that federal law overrides state claims related to interstate and global greenhouse gas emissions.
Utah Attorney General Derek Brown, a Republican, expressed his optimism to reporters after the arguments, citing that the key issue revolves around “who gets to decide the policy.” He characterized Boulder’s claims as “an energy tax dressed up in a fraud lawsuit,” suggesting that they seek to regulate activities happening nationwide, not just in Colorado.
Similarly, Alabama Attorney General Steve Marshall felt reassured after hearing the judges’ questions, particularly those from Justice Brett Kavanaugh. He stated, “We were confident coming in. I feel better having heard… Justice Kavanaugh’s questioning makes it clear that this is not a matter for local Boulder officials to set energy policy for the entire country, but rather it is a question of federal law — specifically Congress’s purview.”
However, Marshall noted the unpredictability of justices’ votes based on their questions. He referenced Justice Amy Coney Barrett’s challenges to the companies’ arguments, suggesting her inquiries were part of her duty to fully understand the advocates’ positions.
“Trying to predict a Supreme Court ruling based solely on oral arguments is risky, but it seems some justices might lean toward deferring to state court actions,” said Zac Morgan from the Washington Legal Foundation. He pointed out that Boulder did not effectively address concerns raised by Justices Barrett and Kavanaugh regarding the differences between regulating greenhouse gases through state court as opposed to through a municipal or state statute, which could conflict with the Constitution.
Justice Barrett challenged the companies, noting that the Clean Air Act’s saving clause “doesn’t say authorize; it says preserve.” She later referred to one of the answers from Shanmugam as “a little slippery.” With Alito absent, her vote could be crucial.
— Simon August (@simonaugustdc) October 5, 2026
Michael R. Williams, West Virginia’s Solicitor General, commented that the discussions reaffirmed their stance that federal law prevents these types of lawsuits multiple times. He emphasizes confidence that no matter the Court’s direction, it will lead to the conclusion that Boulder cannot proceed.
“Justice Kavanaugh’s suggestion indicates that these interstate matters should be governed by federal law rather than the varied state laws across numerous state courts,” Williams added.
The Supreme Court agreed in February to review the case and instructed the parties to clarify whether they have the jurisdiction to adjudicate this dispute.
This case has attracted about 20 amicus briefs, with environmental groups and Democratic-led governments supporting Boulder, while industry and free-speech organizations express concerns about allowing states to hold companies liable for global emissions.
According to Cody L. Reaves from Torridon Law PLLC, the justices actively engaged in tough questioning. Justice Kavanaugh posed particularly sharp inquiries regarding the Court’s precedents on interstate air and water pollution, viewing existing cases as confirming that such pollution is a federal issue unless Congress explicitly preserves state law.
Chief Justice John Roberts focused on the practical outcomes of Boulder’s case, appearing worried about the potential for cities and counties across the nation to duplicate Boulder’s claims, thereby exposing these defendants to significant liabilities.
One week prior to the arguments, Justice Samuel Alito recused himself, which left eight justices to deliberate the case. His absence raises the chance of a tie vote, which would maintain the Colorado Supreme Court ruling allowing Boulder’s lawsuit to proceed without creating a binding national precedent.
Reaves noted the significance of Alito’s absence, mentioning his knack for asking pointed questions that clarify complex issues. He referenced a past dissent by Alito on the importance of preemption in cases where state law interferes with federal authority in foreign relations, a point that surfaced minimally during oral arguments.
This ongoing legal battle has extended into Colorado’s elections. Phil Weiser, the Democratic gubernatorial candidate and current Attorney General, partnered with other Democratic attorneys general to encourage the Supreme Court to allow Colorado courts to address Boulder’s claims. Additionally, Jena Griswold, the Democratic nominee for attorney general, supports Boulder’s lawsuit and has committed to pursuing climate-related legal action if elected.
The outcome of elections may influence the state’s climate litigation strategy, regardless of how the Supreme Court rules in the Suncor case.
