Who Pays for Climate Harm? State Tort Law and Federal Preemption
The Supreme Court’s 2011 ruling in American Electric Power Co. (AEP) v. Connecticut held that the Clean Air Act takes precedence over federal common law public nuisance claims involving greenhouse gas emissions, since Congress has vested the Environmental Protection Agency (EPA) with regulatory authority over those emissions. However, the Court did not rule on whether the Act also preempts tort claims under state law. While it left that matter open and unresolved, it is a question that is now at the heart of climate liability litigation. Today, as cities including Baltimore, Honolulu, and a number of California municipalities file state tort suits against fossil fuel companies for damages and compensation tied to climate-related harm, the fossil fuel industry’s primary line of defense is to argue that the Clean Air Act preempts these claims entirely. However, the defense fails: the displacement of federal common law and preemption of state law are different legal doctrines governed by different standards. A reading of the Clean Air Act’s text, its regulatory structure and its saving clause demonstrates no congressional intent to foreclose state tort remedies.
Displacement asks whether a federal statute has taken the place of judge-made federal law on a given subject. In AEP, the Court concluded that by delegating authority over greenhouse gases to the EPA, Congress had displaced any federal common law nuisance claim aimed at regulating them. However, preemption functions differently, focusing on whether Congress intended a federal statute to supersede state law. In fields such as tort law, public health, and safety where states have traditionally held governing authority, courts begin with a presumption against preemption. For preemption to occur, there must be an express statement in the statute, a congressional intent to occupy the entire field, or an actual conflict between state and federal law that makes compliance with both impossible. The Clean Air Act satisfies none of these with respect to tort claims.
Section 116 of the Clean Air Act includes a savings clause preserving state authority to “adopt or enforce any standard or limitation respecting emissions of air pollutants” or any requirement which is more stringent than federal standards. Congress included this provision as a statute that preserves state regulatory authority and cannot be simultaneously read to eliminate state tort remedies addressing the consequences of the same pollution. If Congress had intended the Clean Air Act to be the only legal framework for all claims related to air pollution, it would not have preserved state authority to exceed federal standards from the beginning. The savings clause, therefore, forecloses the field preemption argument. The Supreme Court’s decision in Wyeth v. Levine (2009) echoes this principle. In Wyeth, the Court held that the Food and Drug Administration’s approval of a drug label did not preempt state tort claims for inadequate warnings. Citing in part the federal statute’s savings clause, Wyeth specifically states that Congress does not “cavalierly pre-empt state-law causes of action.” The Clean Air Act’s savings clause operates the same way: by preserving state authority, the statute cannot be interpreted to eliminate state tort remedies simultaneously.
The functional difference between federal regulation and state tort law reinforces this reading. The Clean Air Act is created to regulate future conduct: it sets prospective nationwide emissions standards and empowers the EPA to enforce this compliance. State tort law addresses, however, past conduct—injuries that have already occurred. A tort judgment does not require the EPA to act, and does not conflict with any provision of the Clean Air Act. Thus, the argument that the Act “occupies the field” confuses the regulation of emissions with the adjudication of harm caused by the emissions. Congress regulated the former but said nothing about eliminating legal remedies for the latter.
The subject matter of these tort claims also undermines the preemption defense. In Baltimore’s case, the underlying tort theory centers on corporate deception: fossil fuel companies knew their products contributed to climate change but still misled the public and regulators about the risks. The issue at play is one of deception, which lies entirely outside the Clean Air Act’s regulatory scope. While the Clean Air Act regulates how much a source may emit, it does not regulate whether corporations tell the truth about the consequences of their products. Because the tortious conduct these claims target falls entirely outside the Act’s reach, there is no federal law for the state claims to conflict with, and preemption has nothing to attach to.
The 2007 Massachusetts v. EPA ruling confirmed that greenhouse gases qualify as “air pollutants” under the Clean Air Act, establishing EPA regulatory authority over emissions. However, recognizing federal regulatory authority over a subject does not make it sufficient to preempt state tort claims and remedies on the same subject. For decades, federal regulation and state tort liability have coexisted; in areas such as pharmaceuticals and workplace safety, comprehensive federal oversight exists alongside state-law remedies. The fossil fuel industry’s preemption argument would have courts treat climate litigation as categorically separate and different from every other area of law where this coexistence is common, without offering any rationale or reasoning behind the distinction. The procedural history of BP P.L.C v. Mayor and City Council of Baltimore (2021) reinforced this idea. In deciding whether Baltimore’s climate tort claims could be removed from state to federal court, the Supreme Court left room for state-law claims to proceed and be heard at the state level. If these claims arose under federal law, removal would have been straightforward. The Court’s treatment of them as state-law claims reinforces that tort remedies and federal regulatory authority occupy different legal space.
The remaining objection from the fossil fuel industry is justiciability: that climate cases are simply too complex for courts to adjudicate. Proponents of this view often refer to Juliana v. United States (2020), decided by the United States Court of Appeals for the Ninth Circuit. In Juliana, the plaintiffs sought recognition for a new constitutional right to a stable climate and requested a comprehensive restructuring of national climate policy—remedies the court concluded would require action by the political branches rather than just the judiciary. However, state tort claims are categorically different from what the Juliana plaintiffs demanded. Rather than asking courts to create new rights or restructure national policy, climate tort cases ask courts to apply existing, long-standing tort principles to determine whether fossil fuel companies should compensate communities for harms their conduct allegedly caused. It is common for courts to adjudicate complex causation in toxic tort and environmental contamination cases, so there is no reason why cases involving climate-related harm should be treated any differently. To treat climate-related harm as beyond the judicial’s reach would be to deny remedy to vulnerable communities, a result that cuts against the common law maxim ubi jus, ibi remedium: where there is a right, there is a remedy.
The savings clause, the difference between regulating future emissions and compensating for past harm, and the decades-long coexistence of federal regulation with state tort remedies all point to the same direction: state climate tort claims should survive preemption. Preempting these claims would centralize climate authority in Congress and the EPA while depriving communities of their legal remedy for harm and shielding corporations that allegedly contributed to it. Congress did not foreclose these claims when it implemented the Clean Air Act, and the statute’s savings clause implies that it deliberately chose not to. What remains before the Court is whether Congress intended to eliminate the legal remedies that states have used for centuries to hold private actors accountable for the harms they cause. How the Court answers that question will shape the future of environmental governance for years to come.
Edited by Leah Druch
This piece was reviewed and finalized by Gabi Fabozzi, Qizhen (Kiara) Ba, and Jasmine Lianalyn Rocha.