The US Supreme Court opened its new term Monday with oral arguments in Suncor Energy v. County Commissioners of Boulder County, a case that could determine whether fossil fuel companies ever face financial accountability for climate damages in American courts. Boulder County filed suit in Colorado state court in 2018, alleging that ExxonMobil and Canada-based Suncor concealed what they knew about climate harm and should share the costs. The companies want the case dismissed on grounds that federal law preempts state courts from hearing climate claims at all. The industry's legal theory is ambitious and, by most accounts, historically unsupported. Exxon and Suncor argue that a body of "federal common law" — rooted in century-old Supreme Court decisions about interstate environmental disputes — strips state courts of jurisdiction over climate cases, even absent any federal statute saying so. They further claim the federal Clean Air Act preempts state-level climate litigation, despite the Act's own text declaring that "air pollution control at its source is the primary responsibility of states and local governments." The stakes are not confined to Boulder. Dozens of state and local governments have filed similar climate liability suits around the country. A ruling in favor of the oil companies would functionally close the courthouse door on all of them. As Columbia Law School's Dennis Fan put it, the industry is "going for the grand slam" — seeking a precedent that would ensure "there will never, ever be climate change litigation again." The Supreme Court's decision to hear the case at all is procedurally unusual. Typically, cases must be fully adjudicated in lower courts before reaching SCOTUS. Here, the justices agreed to intervene while the state case is still ongoing — a move Fan called "incredibly weird." Justice Samuel Alito recused himself, citing no reason but facing pressure over stock holdings in ConocoPhillips and Phillips 66, companies that could indirectly benefit from a pro-industry ruling. The Trump administration filed an amicus brief siding with the oil companies and secured 10 minutes of oral argument time. The legal precedent cuts against the industry. As recently as April 2025, the Court held in Hencely v. Fluor Corp that "there is no federal pre-emption [in isolation] without a constitutional text or a federal statute to assert it." Fan noted that tobacco and opioid companies previously tried the same playbook — arguing that state public nuisance suits should be blocked by federal law — and "failed every single time." The human dimension is concrete. The 2021 Marshall fire in Boulder County, fueled by record warmth and extreme drought that scientists linked to climate change, destroyed neighborhoods and caused an estimated $2 billion in damage. A recent report estimates climate change could cost Colorado up to $37 billion by 2050. Daryl McCool, an artist who lost her home in the fire, attended a rally outside the Court Monday — not as a litigant, but as someone who wants the industry's record of deception examined in open court. A ruling is expected next summer. If Boulder prevails or the Court declines jurisdiction, the case returns to state court and the broader litigation wave continues. If the industry wins, it establishes a shield that no federal statute ever created — one that would require Congress to act if climate accountability is ever to be pursued through the courts again.
