On October 5, 2026, the Supreme Court heard oral arguments in Suncor Energy (U.S.A.) Inc. v. County Commissioners of Boulder County. In a new insight, Director of Energy and Environmental Policy Shuting Pomerleau and Misha Mazalevskyi provides an overview of the case and discusses five potential rulings and their policy implications for federal, state, and local governments, oil and gas companies, and the broader U.S. energy industry.

Key points:

• In the major climate change case, the city and county of Boulder seek to hold energy producers Suncor and ExxonMobil financially liable for localized climate adaptation costs and alleged deceptive marketing practices.
• With Justice Samuel Alito recused, the 8-justice Court evaluated the questions of 1) whether the Court has statutory authority to weigh in on the case which has a pending decision from Colorado State Court; and 2) whether the federal Clean Air Act and federal common law preempt state tort claims involving global greenhouse gas emissions.
• The case has high stakes as the Court’s ruling would affect dozens of other similar lawsuits pending around the country and determine whether state and local governments have the authority to sue fossil fuel companies on the ground of climate change damage.

Read the analysis.