The U.S. Supreme Court is set to hear arguments in a high-profile climate change lawsuit on Monday, marking a significant moment in the ongoing legal battle over the responsibility of major oil companies for global warming. The case, brought by the city and county of Boulder, Colorado, targets ExxonMobil and Canada’s Suncor Energy, alleging that these companies deliberately misled the public for decades about the impacts of climate change and their role in carbon emissions linked to severe weather events damaging the region.

Boulder’s suit, filed under Colorado state law, seeks damages to cover the costs of increasingly frequent wildfires, droughts, health impacts, and infrastructure damage attributed to climate change. The Marshall Fire of 2021, which destroyed over 1,000 homes and caused approximately $2 billion in damage, has intensified local concerns. According to a University of Colorado at Boulder report, Boulder might face $96 million to $157 million in expenses by 2050 to mitigate climate effects such as wildfire resilience and water supply. The lawsuit argues that as early as the 1950s, the American Petroleum Institute and its member companies recognized fossil fuels’ role in rising atmospheric carbon dioxide and climate change but publicly downplayed or cast doubt on these scientific findings.

ExxonMobil and Suncor deny any wrongdoing, asserting that the suit improperly seeks to impose state-level climate policy responsibilities that belong to the federal government. They contend that greenhouse gas emissions regulation is a federal matter under the Constitution because emissions cross state lines. The companies advocate for dismissal of the case, warning that allowing it to proceed could open the door to thousands of similar lawsuits nationwide, potentially resulting in billions in damages and disrupting federally established energy policies. They cite a 2011 Supreme Court precedent that delegated the regulation of carbon emissions to the Environmental Protection Agency (EPA), not state courts.

The legal debate centers on whether federal law preempts Colorado’s authority to hold these companies liable under state law and whether Colorado can impose its regulations on activities that occur outside its borders. Critics argue that allowing such suits risks infringing on the sovereignty of other states and undermines the constitutional balance of federalism. The case’s outcome could define the limits of state-level climate litigation and the extent to which states can seek damages for global environmental harms caused by out-of-state actors.

The dispute has drawn attention from various stakeholders. Boulder officials argue the case addresses the real costs local communities bear due to climate change and seeks accountability for alleged deception by oil companies. Conversely, some Colorado counties reliant on energy production fear that such lawsuits could harm their economies without effectively addressing climate challenges. The Trump administration has sided with the oil companies, emphasizing the federal government’s primacy in regulating greenhouse gases.

Supreme Court Justice Samuel A. Alito Jr. recused himself from the case due to financial conflicts, raising the possibility of a tied decision that could let the lawsuit proceed. The ruling is expected to have wide-reaching implications for future climate change litigation and the balance of regulatory authority between states and the federal government.