U.S. Supreme Court Justice Samuel Alito will not participate in a case involving Exxon Mobil and Suncor Energy's effort to stop Boulder, Colorado's climate-related lawsuit. The court clerk informed the parties that Alito had decided not to continue participating, without explaining the decision. Alito owns stock in several oil and gas companies, including ConocoPhillips and Phillips 66, though not Exxon or Suncor; both portfolio companies face separate climate-related litigation. He had initially rejected recusal calls from watchdog and environmental groups, but also stepped aside when the Boulder litigation previously reached the court in 2023. The Oct. 5 case will examine whether federal law blocks state-law claims seeking damages over greenhouse-gas emissions and whether the court has jurisdiction to intervene at this stage. The Trump administration supports Exxon and Suncor, arguing that federal law preempts Boulder's claims. The outcome could affect dozens of comparable state and local lawsuits against fossil-fuel companies.