Climate change lawsuits against oil companies are at a decision point. Dozens of suits filed by states, cities, counties, and tribal governments accuse fossil fuel producers of concealing what they knew about the climate risks of their products while funding efforts to discredit climate science. Whether any of them can go to trial depends largely on a single question now before the U.S. Supreme Court: can state and local governments use their own courts and their own tort laws to sue oil companies for climate harms, or does federal law block them?
What the Lawsuits Claim
The theory running through most of these cases is not that burning fossil fuels is illegal. It is that the companies knew for decades their products would drive climate change and misled the public and consumers about it. Plaintiffs bring state-law claims for public and private nuisance, trespass, failure to warn, unjust enrichment, civil conspiracy, and violations of state consumer-protection statutes. They seek damages for localized harms — wildfires, drought, flooding, sea-level rise, heat waves — and, in some cases, penalties tied to the companies’ historical share of emissions.
Defendants typically include ExxonMobil, Chevron, BP, Shell, ConocoPhillips, Phillips 66, Suncor, and the American Petroleum Institute. Complaints often name the foreign parent entities such as BP P.L.C. and Shell PLC alongside their American subsidiaries, on the theory that the parents controlled companywide climate strategy and messaging.{1Office of the Attorney General for the District of Columbia. District of Columbia v. Exxon Mobil Corp. Complaint}
The Preemption Question That Decides Most Cases
The industry’s central defense is that federal law preempts these state-law claims. The argument: climate change is inherently national and international, Congress gave the EPA authority over greenhouse gas emissions through the Clean Air Act, and federal law occupies the field. Under a doctrine called displacement, courts have reasoned that state tort claims amounting to regulation of interstate emissions cannot proceed.
That argument has won several high-profile dismissals. In April 2021, the Second Circuit affirmed the dismissal of New York City’s nuisance suit against five major producers, holding that federal common law displaced the city’s state-law claims and that letting the case proceed would “risk upsetting the careful balance” between climate policy, energy production, and national security.{2Jones Day. Second Circuit Affirms Dismissal of New York City’s Climate Suit}
In March 2026, the Supreme Court of Maryland affirmed the dismissal of consolidated suits by Baltimore, Anne Arundel County, and Annapolis against 26 oil and gas companies, ruling that the tort claims were preempted and adding that imposing a duty to “warn the entire human race” of climate change effects would “stretch Maryland tort law beyond manageable bounds.”{3Maryland Courts. Mayor and City Council of Baltimore v. BP P.L.C.}
New Jersey’s suit, filed in October 2022 by Attorney General Matthew Platkin against ExxonMobil, BP, Chevron, ConocoPhillips, Phillips 66, Shell, and the American Petroleum Institute,{4NJ Office of Attorney General. Lawsuit Filed by AG, NJDEP, and Division of Consumer Affairs} met the same fate. On February 5, 2025, State Superior Court Judge Douglas Hurd dismissed the case, ruling that the state’s claims were “entirely about addressing the injuries of global climate change” and that “only federal law can govern Plaintiffs’ interstate and international emissions claims.”{5ESG Dive. New Jersey Judge Dismisses State’s Climate Lawsuit} The dismissal was without prejudice. The state’s appeal now sits before the New Jersey Appellate Division in abeyance, waiting on the Supreme Court.{6Climate Case Chart. Platkin v. Exxon Mobil Corp.}
The Supreme Court Case That Will Settle It
On February 23, 2026, the U.S. Supreme Court granted certiorari in Suncor Energy (U.S.A.) Inc. v. County Commissioners of Boulder County.{7SCOTUSblog. Suncor Energy Inc. v. County Commissioners of Boulder County} The case comes out of a 2018 lawsuit by Boulder County and the City of Boulder against Suncor and ExxonMobil alleging localized harms — wildfires, drought, property damage — and asserting state-law claims for public and private nuisance, trespass, unjust enrichment, and civil conspiracy. The Colorado Supreme Court ruled in May 2025 that those claims were not preempted and could proceed toward trial.
The Court has directed the parties to brief two questions: whether federal law precludes state-law claims seeking relief for injuries allegedly caused by interstate and international greenhouse gas emissions, and whether the Court has jurisdiction to hear the case at all.{8U.S. Chamber of Commerce. ExxonMobil Corp. v. Board of County Commissioners of Boulder County} Suncor and ExxonMobil filed their merits brief on May 14, 2026, arguing that the Constitution bars states from using tort law to regulate a “uniquely interstate and international” phenomenon, that the Clean Air Act comprehensively preempts such claims, and that the suits interfere with federal authority over foreign affairs.{9Supreme Court of the United States. Brief for Petitioners, Suncor Energy v. Boulder County} Boulder County’s brief is due July 27, 2026, with oral argument expected during the October 2026 term.
Courts around the country have paused proceedings to wait. New Jersey’s appeal is in abeyance.{6Climate Case Chart. Platkin v. Exxon Mobil Corp.} Defendants in Hawaii’s state-court suit against BP and other producers have asked for a stay, and Washington tribal cases face similar stay requests.{10Columbia Law School. Climate Litigation Updates, March 2026} A broad ruling that federal law forecloses state-law climate claims would likely end the wave. A narrow ruling, or a finding of no jurisdiction, would let the cases move forward.
The EPA Repeal That Could Weaken the Industry’s Defense
A wrinkle has arrived from an unexpected direction. On February 12, 2026, the EPA under Administrator Lee Zeldin finalized the rescission of the 2009 Greenhouse Gas Endangerment Finding, declaring that the Clean Air Act “does not authorize EPA to regulate GHG emissions from new motor vehicles.”{11U.S. EPA. Final Rule: Rescission of Greenhouse Gas Endangerment Finding} The repeal eliminated federal vehicle emission standards for greenhouse gases. A coalition of 25 state attorneys general, along with a dozen cities and counties and the Governor of Pennsylvania, filed a petition for review in the D.C. Circuit on March 19, 2026.{12State Impact Center. Twenty-Five AGs Filed Lawsuit Challenging EPA’s Endangerment Finding Repeal}
Here is the paradox for climate defendants. For more than a decade, oil companies argued the Clean Air Act preempts state tort suits because Congress gave the EPA authority over greenhouse gases. Now the EPA itself says it lacks that authority. If courts accept the agency’s new position, the displacement shield that produced dismissals in New York City, Baltimore, and New Jersey could weaken. One attorney told E&E News the repeal could mark “the end of displacement.”{13E&E News. EPA Endangerment Repeal Could Expose Industry to Legal Blowback} Boulder County itself flagged the shift in briefing to the Supreme Court.{14Sierra Club. Unintended Consequences Memo} Industry groups have pushed back, arguing that preemption depends on Congress’s intent when it wrote the Clean Air Act, not on what the current administration chooses to do with that authority. The Edison Electric Institute warned in filings that stripping the EPA of regulatory authority “could fatally undermine” the displacement defense.
Cases Still Moving Forward
Not every climate suit has been dismissed. Several have survived motions to dismiss and are moving toward discovery or trial.
The District of Columbia’s consumer-protection lawsuit against ExxonMobil, BP, Chevron, and Shell, filed in 2020, remains active. In April 2025, the D.C. Superior Court denied the companies’ motions to dismiss, rejecting arguments based on Clean Air Act preemption, the First Amendment, and puffery.{15Climate Case Chart. District of Columbia v. Exxon Mobil Corp.} In October 2025, the court denied reconsideration and refused to certify the denial for interlocutory appeal.
Hawaii filed a new lawsuit against seven fuel companies on May 1, 2025, alleging they were “fully aware and substantially certain” their activities would cause harm.{16JURIST. US Justice Department Sues Four States Over Climate Initiatives} Minnesota, Vermont, Connecticut, and Maine have each defeated motions to dismiss.{17Center for Climate Integrity. 2025: The Year in Big Oil Accountability} Pacific Northwest tribal governments won a ruling allowing their claims to proceed in Washington state court. The estate of Juliana Leon has filed what appears to be the first wrongful death lawsuit against oil companies for climate-related harm, tied to the 2021 Pacific Northwest heat dome; a Washington federal court rejected efforts to move the case to federal court, so it will proceed in state court.
A Different Route to Dismissal in North Carolina
Most dismissals have relied on preemption, but a February 2026 ruling from North Carolina took a different path. In Town of Carrboro v. Duke Energy Corp., Special Superior Court Judge Mark Davis dismissed the town’s nuisance, trespass, and negligence claims under the political question doctrine, ruling that energy policy and emission standards are committed to the legislature and executive agencies, not the courts.{18Daily Tar Heel. City of Carrboro Duke Energy Lawsuit Dismissed} He found no “manageable standards” for deciding how much global climate change was attributable to one company’s alleged disinformation, calling the required causal analysis “rank speculation” about “literally billions of unrelated emitters dispersed throughout the globe.”{19NC Business Court. Town of Carrboro v. Duke Energy Corp.} Judge Davis bypassed the preemption question entirely.
The Federal Government Sues the States
The Trump administration has gone beyond defending preemption in existing suits. On April 30 and May 1, 2025, the Department of Justice filed lawsuits against four states to block their climate accountability efforts directly.{20U.S. Department of Justice. Justice Department Files Complaints Against Hawaii, Michigan, New York, and Vermont}
- Against New York and Vermont, the DOJ sued to invalidate “Climate Superfund” laws modeled on the 1980 federal Superfund act, which would assess penalties against energy companies for climate-related costs. New York’s law alone targets an estimated $75 billion in penalties.
- Against Hawaii and Michigan, the DOJ sued to prevent them from filing or pursuing state-court climate suits against fossil fuel companies.
The DOJ argued that all four state actions are preempted by the Clean Air Act, violate the Constitution’s allocation of power over interstate commerce and foreign affairs, and burden domestic energy production. Acting Assistant Attorney General Adam Gustafson said that “when states seek to regulate energy beyond their constitutional or statutory authority, they harm the country’s ability to produce energy and they aid our adversaries.”{16JURIST. US Justice Department Sues Four States Over Climate Initiatives}
The Shell Case in the Netherlands
The most prominent climate case outside the United States involves Shell PLC. In 2021, a Dutch district court ordered Shell to reduce its aggregate carbon emissions — including emissions from customers burning its products — by 45% by 2030. In November 2024, The Hague Court of Appeal overturned that specific order, finding insufficient scientific consensus to impose a particular reduction percentage on a single company and that such an order would be “ineffective” because other companies would replace Shell’s market share.{21Climate Case Chart. Milieudefensie et al. v. Royal Dutch Shell PLC} The appeals court did affirm that Shell has an “unwritten” duty of care under Dutch law to contribute to climate change mitigation.
Milieudefensie, the Dutch environmental group behind the case, appealed to the Supreme Court of the Netherlands on February 11, 2025, seeking a specific mandatory reduction target. Shell filed its defense in November 2025, and the Dutch Supreme Court held a hearing on May 22, 2026.{22Shell. Climate Case} A ruling is pending. The Dutch case does not bind U.S. courts, but it addresses a parallel question about whether a single company can be ordered to cut its emissions at a set rate.
Where Things Stand
Climate accountability litigation is frozen around a single upcoming ruling. The Supreme Court’s decision in Suncor v. Boulder County, expected during the October 2026 term, will likely determine whether state and local governments can use their own legal systems to seek damages from fossil fuel companies for climate change. Appeals from New Jersey to Maryland, and stay requests in Hawaii and Washington, are waiting on that answer. The EPA’s repeal of the endangerment finding has added a layer of uncertainty that cuts against the preemption defense oil companies have relied on for years, and the DOJ’s suits against New York, Vermont, Hawaii, and Michigan mark an unprecedented federal effort to shut down state climate cases at the source. The next twelve months will decide the shape of corporate climate liability in the United States.