Supreme Court Justices Skeptical of Boulder Climate Lawsuit

The Supreme Court appeared skeptical Monday of allowing Boulder County, Colorado, to sue energy companies Suncor and Exxon Mobil for alleged contributions to climate change.

During oral arguments on the first day of its new term, eight justices questioned the scope of state law claims against fossil fuel producers for global harms. Chief Justice John Roberts asked if allowing the suit would lead to municipalities in every state filing similar actions. Justice Brett Kavanaugh cited four precedents suggesting interstate air and water pollution are federal matters unless Congress specifies otherwise.

The case originated in 2018 when Boulder sued, seeking damages for climate change impacts. The Colorado Supreme Court had previously allowed the lawsuit to proceed, but Suncor and Exxon Mobil appealed, arguing federal law preempts such claims. Kannon Shanmugam, arguing for the energy companies, stated the case involves an unprecedented effort to use state law to regulate global conduct.

The Trump administration backed the energy companies. Justice Samuel Alito recused himself from the case, leaving open the possibility of a 4-4 split decision, which would allow the Colorado Supreme Court's ruling to stand. The justices also considered whether they have jurisdiction to review the Colorado Supreme Court's decision. The outcome could have broad ramifications for more than two dozen similar lawsuits filed by local governments nationwide.