The U.S. Supreme Court heard oral arguments Monday in Suncor v. Boulder, a case that could determine whether the city and county of Boulder can continue pursuing a lawsuit against ExxonMobil and Suncor Energy over alleged damages tied to climate change.
Boulder originally filed the lawsuit in 2018, accusing the two oil companies of knowingly contributing to climate change for decades while misleading the public about the risks of fossil fuels. The complaint cites a 1977 internal ExxonMobil memo, circulated among top company managers, stating that “current scientific opinion overwhelmingly favors” the idea that fossil fuels contribute to rising carbon dioxide emissions.
The central legal question is whether federal law preempts states and cities from suing oil companies under state tort law for damages linked to emissions that cross state lines. Boulder’s attorney, Kevin Russell, told the justices that states have long held the authority to provide remedies for injuries within their borders “even when the conduct causing those injuries occurred elsewhere.” Boulder maintains the case is not an attempt to set national climate policy but rather a matter of state accountability.
ExxonMobil and Suncor argue the opposite: because greenhouse gas emissions are global in nature, they say, Colorado cannot use state law to assign liability for emissions that largely originated elsewhere. The companies contend the dispute belongs under federal law instead.
Questions From the Bench
During arguments, Justice Clarence Thomas asked Russell whether Boulder’s legal theory could expose businesses well beyond oil producers — including large retailers — to similar lawsuits. Russell acknowledged that “nothing in our theory prevents that,” though he noted state tort law could still impose limits.
Justice Brett Kavanaugh raised concerns about the financial fallout of widespread litigation, suggesting that enough lawsuits could “bankrupt” defendants, and questioned whether nearly any manufacturer or business could eventually face comparable claims.
Justice Samuel Alito has recused himself from the case without explanation.
Broader Stakes
Boulder’s case is one of roughly 30 similar lawsuits pending around the country, including in Portland and Baltimore, making the outcome closely watched well beyond Colorado. Energy policy analysts and industry advocates have argued the case could have sweeping financial consequences.
Jason Isaac, CEO of the American Energy Institute, said a ruling in Boulder’s favor could allow a flood of new lawsuits from other jurisdictions. “There are over 90,000 levels of government — government entities just in the United States alone — that could also begin lawsuits against energy companies,” Isaac said, adding that defense costs could drive up consumer prices. He also warned that even a 4-4 split among the justices could leave the lower court’s ruling in place, though it would not set nationwide precedent.
O.H. Skinner, executive director of the Alliance for Consumers, argued the litigation amounts to an attempt to achieve policy goals through the courts that have failed in Congress. “It’s an effort to get a backdoor carbon tax, because carbon taxes have never passed in Congress, or to bankrupt the energy industry,” Skinner said. He also suggested liability could extend to gas stations, automakers and utilities, not just oil producers, saying “to the left, climate change is everything and everything is climate change.”
David Bookbinder, who previously served as counsel of record for Boulder but is no longer involved in the case, described the lawsuit at a Federalist Society forum last year as a way of implementing what he called an “indirect carbon tax.”
Isaac countered that climate cases differ from past litigation against tobacco or opioid manufacturers because greenhouse gas emissions come from countless global sources, making it harder to isolate responsibility. “Emissions are a global phenomenon,” he said.
Other states have moved in the opposite direction from Boulder’s approach. Utah has barred this type of state tort lawsuit altogether. Utah Attorney General Derek Brown said a win for Colorado could raise gas prices nationwide. “If the energy companies were to lose and Colorado were to win, this would in effect drive up the prices of gas all across the country,” Brown said, adding that such decisions should be left to Congress.
A ruling from the Supreme Court is expected at a later date.
