The US Supreme Court heard arguments on Monday over whether a climate damages lawsuit against Suncor Energy and ExxonMobil can proceed in state court. The hearing opened the court’s new nine-month term.

Boulder County officials are seeking to make the companies pay a share of climate-related costs borne by local taxpayers. Suncor and ExxonMobil argue that federal law prevents state courts from hearing the claim.

The justices’ position was unclear after nearly two hours of arguments. If they side with Boulder County, or decide they lack jurisdiction, the case would continue in state court. A ruling for the companies could affect dozens of similar cases brought by state and local governments across the US.

Justice Samuel Alito has recused himself from the case. During the hearing, the companies’ lawyer argued that lawmakers, rather than state courts, should address climate change claims.