No. 25-170October Term 2026Argument ScheduledUpdated Sep 5, 2026
Climate change liability
Suncor Energy v. Boulder County
Case status
Where it stands
Oral argument October 5, 2026
- Next
- Decision expected by late June 2027
- Also that day
What it's about
Boulder County and the City of Boulder sued Exxon Mobil and Suncor entities under state law, alleging that their fossil-fuel activities contributed to climate change and harmed local property and residents. The Supreme Court will decide whether it has authority to hear the case and whether federal law bars these state-law claims involving the effects of interstate and international greenhouse-gas emissions.
Question presented
1. Whether federal law precludes state-law claims seeking relief for injuries allegedly caused by the effects of interstate and international greenhouse-gas emissions on the global climate. 2. Whether this Court has statutory and Article III jurisdiction to hear this case.
What happens next
Expected by late June 2027
Argument is on the calendar for October 5, 2026. Decisions typically follow within about 98 days of argument. Nearly all opinions are released before the term ends in late June or early July 2027.
Why it matters
The case could affect whether local governments can use state-law lawsuits to seek relief for climate-related harms. For example, Boulder residents and property owners could be affected by whether the local claims may continue.
The dispute is part of wider litigation over who may be held responsible for alleged harms from greenhouse-gas emissions that cross state and national borders.
Case file
- Docket
- 25-170
- Status
- Argument Scheduled
- Argument
- From
- Supreme Court of Colorado
- Documents
- 2
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AI analysis generated: Case Briefing
Brief added: Petition
Brief added: Questions Presented
More questions
- What is at stake in Suncor Energy v. Boulder County?
- The Court will consider whether federal law blocks Boulder’s state-law climate claims and whether the Court has authority to hear the case.
- Who could be affected by the Suncor Energy case?
- Boulder County, the City of Boulder, local residents, property owners, and the Exxon Mobil and Suncor entities could be affected.
- When is the next step in Suncor Energy v. Boulder County?
- The Court is scheduled to hear oral argument on October 5, 2026. A decision usually follows later in the same term.
Sources
Primary materials plus reporting. Best-effort analysis: this explainer relies on a mix of primary materials and trusted secondary sources. Official filings and opinions remain authoritative.