## Facts

- The City of New York sued five multinational oil companies in federal court under diversity jurisdiction.
- The City asserted New York tort claims for public nuisance, private nuisance, and trespass.
- The City sought money damages for alleged climate-change-related harms to City infrastructure and residents, including costs associated with sea-level rise, flooding, and heat impacts.
- The City alleged defendants produced, promoted, and sold fossil fuels for decades while knowing combustion would emit greenhouse gases and contribute to global warming.
- Although framed as challenging fossil-fuel marketing and sales, the City’s theory of liability depended on worldwide greenhouse gas emissions over long periods and their alleged contribution to climate change.
- The district court dismissed, concluding the claims were governed by federal common law, that any domestic-emissions federal common-law claim was displaced by the Clean Air Act, and that claims tied to foreign emissions could not proceed due to separation-of-powers and foreign-policy concerns.

## Issues

1. Whether state tort law can supply causes of action seeking damages for injuries allegedly caused by global climate change driven by worldwide greenhouse gas emissions.
2. Whether claims styled as state nuisance and trespass are governed instead by federal common law because they target transboundary, international air pollution.
3. Whether the Clean Air Act displaces any federal common-law claim concerning domestic greenhouse gas emissions.
4. Whether federal common-law claims premised on foreign emissions may proceed absent congressional authorization, given foreign-policy and separation-of-powers constraints.

## Decision

- The Second Circuit affirmed dismissal of the complaint in full.
- The court held the City’s claims, properly understood, were governed by federal common law because they sought damages for injuries caused by worldwide greenhouse gas emissions, a matter requiring a uniform federal rule.
- The court held any federal common-law claim addressing domestic greenhouse gas emissions is displaced by the Clean Air Act, which assigns regulatory authority to the Environmental Protection Agency.
- The court held federal common law should not be extended to impose liability for foreign emissions absent congressional direction due to foreign-policy implications and separation-of-powers concerns.

## Legal Principles

- Claims seeking damages for harms allegedly caused by global greenhouse gas emissions are governed by federal common law rather than state tort law because of the transboundary and international character of the alleged pollution and the federal interests implicated.
- The Clean Air Act displaces federal common-law causes of action concerning domestic emissions of air pollutants, including greenhouse gases, by providing a statutory scheme and delegating regulatory authority to EPA.
- Federal courts should not create or extend federal common-law remedies imposing liability for foreign emissions where doing so would intrude on the political branches’ control over foreign relations and lacks congressional authorization.
- Recharacterizing climate-change claims as targeting fossil-fuel production, promotion, or sales does not avoid federal-law control when the alleged injury and causation theory ultimately depend on global emissions.

## Conclusion

The Second Circuit held that New York City could not use state tort law to recover climate-adaptation damages from oil companies for alleged harms caused by global greenhouse gas emissions; federal common law governed, domestic-emissions claims were displaced by the Clean Air Act, and foreign-emissions claims were barred absent congressional authorization.


City of New York v. Chevron Corp., 993 F.3d 81 (2d Cir. 2021)