The Supreme Court began its new term Monday with sharp questions for both sides in a climate lawsuit brought by Boulder, Colorado, and its county against Exxon Mobil and Suncor Energy.

Boulder officials allege the companies misled consumers about the climate effects of greenhouse gases from their products. They say climate change is raising local costs, including spending to reduce wildfire risks. The companies deny the allegations and argue that a national and international issue cannot be litigated in state courts.

The companies want the lawsuit dismissed. A ruling could affect more than two dozen similar cases brought by local governments nationwide. Chief Justice John Roberts questioned whether allowing Boulder's case to proceed would prompt more municipalities to sue.

Justice Samuel Alito recused himself, leaving eight justices to hear the case. A 4-4 split could let Boulder's lawsuit move forward without resolving the wider legal questions.