More than 70 U.S. states, cities, tribes, and local governments have filed major climate change lawsuits against oil companies, accusing firms including ExxonMobil, Chevron, Shell, BP, and ConocoPhillips of knowing for decades that burning fossil fuels would destabilize the climate and running disinformation campaigns to delay action. The entire wave of litigation now hangs on a single U.S. Supreme Court case scheduled for argument during the October 2026 term, which could decide whether any of these suits can proceed at all.
The Supreme Court Case That Could End Most of Them
On February 23, 2026, the Supreme Court agreed to hear Suncor Energy (U.S.A.) Inc. v. County Commissioners of Boulder County.1PBS NewsHour. Supreme Court Agrees to Hear Arguments From Oil and Gas Companies Trying to Block Climate Change Lawsuits Boulder County and the City of Boulder had sued Suncor and ExxonMobil under state tort law, alleging public nuisance, private nuisance, trespass, and unjust enrichment tied to the companies’ role in climate change.2Columbia Law School Sabin Center for Climate Change Law. Climate Litigation Updates
The question before the Court is whether federal law precludes state-law tort claims seeking damages for injuries caused by greenhouse gas emissions. The oil companies argue emissions are a national and international issue that belongs in federal court, where similar claims have been dismissed. Boulder counters that nothing stops state courts from addressing local harms caused by out-of-state conduct.1PBS NewsHour. Supreme Court Agrees to Hear Arguments From Oil and Gas Companies Trying to Block Climate Change Lawsuits
The Trump administration filed an amicus brief backing the companies, warning that allowing the cases to proceed would mean “every locality in the country could sue essentially anyone in the world for contributing to global climate change.”1PBS NewsHour. Supreme Court Agrees to Hear Arguments From Oil and Gas Companies Trying to Block Climate Change Lawsuits3Inside Climate News. Supreme Court Looks at State, City Oil Climate Lawsuits4U.S. Supreme Court. Docket No. 25-170, Suncor Energy v. County Commissioners of Boulder County5Columbia Law School Sabin Center for Climate Change Law. Supreme Court Agrees to Hear Fossil Fuel Companies’ Appeal in Boulder Climate Case
A ruling for the oil companies could shut down roughly three dozen pending state and local climate suits.6Stateline. Supreme Court Takes Up Climate Case Testing Local Lawsuits Against Oil Companies Several cases have already been stayed or placed in limbo awaiting the outcome, including New Jersey’s appeal in Platkin v. Exxon Mobil Corp. and Hawaii’s state-level case against BP.2Columbia Law School Sabin Center for Climate Change Law. Climate Litigation Updates
The Biggest Active Cases
Honolulu v. Sunoco
The City and County of Honolulu’s 2020 suit is among the most advanced. The Supreme Court denied the companies’ petitions to dismiss in January 2025, and the Hawaii Circuit Court has since denied defense motions for summary judgment on personal jurisdiction and statute-of-limitations grounds.7Climate Case Chart. City and County of Honolulu v. Sunoco LP Discovery is proceeding toward a possible trial, though no date has been set.8Reuters. U.S. Supreme Court Rejects Bid by Oil Companies to Toss Honolulu’s Climate Suit Honolulu is seeking unspecified monetary damages for infrastructure harm from sea-level rise, heat waves, and other impacts.
Multnomah County’s $52 Billion Heat Dome Suit
Multnomah County, Oregon, filed suit in June 2023 against more than a dozen fossil fuel companies, the American Petroleum Institute, the Western States Petroleum Association, and consulting firm McKinsey & Company. The county alleges the defendants ran a deceptive campaign to sell fossil fuels while suppressing internal knowledge about climate damage, contributing directly to the June 2021 Pacific Northwest heat dome that killed 69 people in the county.9Multnomah County. Climate Accountability Litigation The claims include fraud, negligence, public nuisance, and trespass.
The county is seeking $50 million in past damages, $1.5 billion in future economic damages, and a $50 billion abatement fund for climate adaptation and infrastructure.10Climate Case Chart. County of Multnomah v. Exxon Mobil Corp. The Oregon Circuit Court denied the defendants’ motion to stay proceedings pending the Boulder decision, citing potential prejudice from aging witnesses and lost evidence. As of mid-2026, motions to dismiss are pending and no trial date has been set.11Oregon Public Broadcasting. Multnomah County Lawsuit, Big Oil, Trump Delays
Washington Tribal Lawsuits
The Shoalwater Bay Indian Tribe and the Makah Indian Tribe filed separate climate suits against ExxonMobil and other companies in Washington Superior Court. On April 29, 2026, the court denied the defendants’ motions to dismiss, ruling that federal law did not preempt or preclude the tribes’ state-law claims, that the claims were timely, and that the tribes adequately stated causes of action for public nuisance and violations of the Washington Products Liability Act. A day later, the court denied an emergency request to stay proceedings pending the Boulder case, finding a stay would “greatly prejudice” the tribes.12Columbia Law School Sabin Center for Climate Change Law. Climate Litigation Updates
Baltimore and Maryland
Baltimore, Annapolis, and Anne Arundel County have been fighting to keep their 2018 climate case against BP and others alive. On March 19, 2026, the Maryland Supreme Court denied the oil companies’ motion to stay the appeal of a trial court’s dismissal, allowing the litigation to continue.2Columbia Law School Sabin Center for Climate Change Law. Climate Litigation Updates
New Legal Theories: Wrongful Death and Insurance Costs
The First Climate Wrongful Death Case
In May 2025, Misti Leon filed what experts identified as the first wrongful death lawsuit against fossil fuel companies linked to climate change. Her mother, Juliana Leon, died on June 28, 2021, from hyperthermia after being overcome by heat while in her car in Seattle during the Pacific Northwest heat dome. Her internal body temperature reached 110 degrees Fahrenheit.13The New York Times. Oil Companies Wrongful Death Lawsuit Heat Dome14Courthouse News Service. Oil Companies Face First-Ever Wrongful Death Lawsuit Over Climate Change
Filed in King County Superior Court, the suit names ExxonMobil, Chevron, Shell, ConocoPhillips, and others, alleging product liability and public nuisance. It contends decades of misinformation about fossil fuels prevented society from preparing for extreme heat. The suit seeks a jury trial, unspecified monetary damages, and a court-ordered public education campaign on climate change, but explicitly does not seek to restrict fossil fuel sales.14Courthouse News Service. Oil Companies Face First-Ever Wrongful Death Lawsuit Over Climate Change Defendants removed the case to federal court, but a U.S. district judge sent it back to state court in October 2025. In April 2026, the state court denied the defense request to stay the case pending Boulder, and motions to dismiss are being briefed.15Climate Case Chart. Leon v. Exxon Mobil Corp.
Homeowners Sue Over Insurance Spikes
In November 2025, Washington homeowners filed Kennedy v. Exxon et al., the first class action alleging that fossil fuel companies’ climate deception caused a spike in homeowners’ insurance costs. Filed in the U.S. District Court for the Western District of Washington, the suit names ExxonMobil, Shell, Chevron, BP, ConocoPhillips, and the American Petroleum Institute. Claims include federal RICO racketeering, conspiracy, unjust enrichment, and consumer protection violations.16Inside Climate News. Washington Homeowners Sue Oil Companies Over Insurance Rates17E&E News. Lawsuit Against Oil Majors Is First to Target Rising Insurance Costs The case is seeking national class certification.
Cases That Have Been Dismissed
Not every climate suit has survived. In February 2026, a North Carolina court dismissed Town of Carrboro v. Duke Energy Corp., ruling the claims were nonjusticiable under the political question doctrine. The judge found that energy policy and emissions involve “unknowable” causal questions delegated to other branches of government.2Columbia Law School Sabin Center for Climate Change Law. Climate Litigation Updates
In May 2025, a Pennsylvania judge dismissed Bucks County’s lawsuit against BP, Chevron, ExxonMobil, ConocoPhillips, Phillips 66, Shell, and the American Petroleum Institute with prejudice, meaning the county cannot refile. Judge Stephen Corr ruled the claims were “so intertwined with emissions” that no state court in Pennsylvania could hear them, and that “Pennsylvania cannot apply its own law to claims dealing with air in its ambient or interstate aspect.”18ESG Dive. Pennsylvania Judge Dismisses Bucks County Climate Lawsuit Against Oil Majors The county had pointed to deadly flooding in July 2023, when roughly seven inches of rain fell in 45 minutes and killed at least seven people, as evidence of climate harms it sought to recover costs for.19Philadelphia Inquirer. Bucks County Big Oil Lawsuit Climate Change
Puerto Rico voluntarily dismissed its 2024 climate lawsuit in May 2025, and Charleston, South Carolina decided not to appeal after its case was dismissed.20The Guardian. Climate Accountability Lawsuits US
Federal Pushback From the Trump Administration
On April 8, 2025, President Trump signed an executive order titled “Protecting American Energy from State Overreach,” directing the Attorney General to identify state and local laws that burden domestic energy production and to “expeditiously take all appropriate action” to stop their enforcement.21The White House. Protecting American Energy From State Overreach The order specifically targets climate change litigation, state “climate Superfund” laws, and California’s cap-and-trade market.
In May 2025, the Department of Justice sued both New York and Vermont to invalidate their climate Superfund statutes, which impose financial liability on fossil fuel companies for historical greenhouse gas emissions. The DOJ argues the state laws are preempted by the Clean Air Act, violate the Commerce Clause and Due Process Clause, and infringe on federal authority over foreign affairs.22U.S. Department of Justice. Justice Department Files Motion for Summary Judgment to Challenge Vermont’s Climate Superfund Law23Vinson & Elkins. Trump Administration Sues New York and Vermont Over Climate Superfund Legislation The DOJ filed a motion for summary judgment in the Vermont case in September 2025. Both lawsuits remain pending.
In April 2026, Rep. Harriet Hageman and Sen. Ted Cruz introduced the Stop Climate Shakedowns Act of 2026, which would prohibit climate liability lawsuits in any court, mandate dismissal of all pending cases, void existing state climate Superfund laws, and establish exclusive federal authority over greenhouse gas regulation.24Senator Ted Cruz. Sens. Cruz, Cotton, Budd, Lee Introduce Bill to Combat Climate Lawfare and Defend American Energy Advocates have raised concerns it could be folded into larger budget legislation to avoid a Senate filibuster.25Mother Jones. Republicans’ Bills to Shield Big Oil From Climate Liability Lawsuits
The Legal Theories and the Defenses
An earlier wave of climate cases filed before 2017 largely relied on federal common law nuisance claims. Those failed after the Supreme Court ruled in American Electric Power v. Connecticut (2011) that the Clean Air Act displaced federal common law claims over carbon dioxide emissions.26McKinney Law, Indiana Law Review. Climate Change Litigation and the Clean Air Act
The current “second wave” takes a different approach. Plaintiffs file in state court under state law, focusing not on emissions themselves but on the marketing, promotion, and concealment of information about fossil fuels. Common theories include:
- Public and private nuisance, arguing fossil fuel production and promotion interfere with public rights and private property use.
- Negligence and failure to warn, alleging companies knew about climate risks and had a duty to warn the public, which they breached through active concealment.
- Consumer protection and fraud, claiming deceptive marketing misled consumers about the safety of fossil fuel products.
- Products liability, arguing fossil fuels are defective products given their climate risks and the companies’ failure to warn.
- Unjust enrichment, contending companies profited by externalizing the costs of climate damage onto communities.
Fossil fuel companies have responded with recurring defenses. They argue the Clean Air Act preempts state-law claims, that the cases raise nonjusticiable political questions best left to Congress and the executive branch, and that allowing state courts to regulate a global issue intrudes on federal foreign affairs authority.27The Conversation. The US Constitution and Laws Do Not Protect Oil Companies From Being Sued Over the Harm They Cause to the Climate Companies have also raised First Amendment defenses, arguing that lawsuits targeting their public statements about climate science amount to punishing protected speech, and have filed anti-SLAPP motions in roughly a third of active cases. Courts have largely rejected these speech-based arguments so far.28Environmental Health News. Oil Companies Use Free Speech Claims to Challenge Climate Lawsuits
One complication for the industry: the Trump administration’s repeal of the EPA’s 2009 “endangerment finding,” which had been the scientific basis for federal greenhouse gas regulation, may have weakened the companies’ preemption argument. With no federal regulatory framework governing emissions, it becomes harder to argue federal law displaces state-level claims.6Stateline. Supreme Court Takes Up Climate Case Testing Local Lawsuits Against Oil Companies
Have Any Plaintiffs Won Money?
As of mid-2026, no major climate accountability lawsuit against a fossil fuel company in the United States has produced a trial verdict or a public damages award. Procedural battles over jurisdiction and preemption have consumed years, and no second-wave case has yet reached a trial on the merits.
Internationally, a German court ruled that major corporate emitters like RWE can in principle be held liable for their contributions to climate change, though it dismissed the specific damages claim brought by a Peruvian farmer. A Dutch court separately found Shell legally responsible for its carbon emissions. Neither case resulted in a monetary damages award.29Green Central Banking. RWE Climate Verdict Paves Way for More Cases Against Companies
The Supreme Court weighed in on a related but distinct case in April 2026, Chevron USA Inc. v. Plaquemines Parish, involving Louisiana parishes suing oil companies for coastal wetlands destruction under state environmental law. The Court vacated the Fifth Circuit’s judgment and sent the case back, ruling that Chevron could remove the case to federal court under the federal officer removal statute because the challenged crude-oil production was connected to wartime federal contracts.30U.S. Supreme Court. Chevron USA Inc. v. Plaquemines Parish, No. 24-813 That ruling turned on a narrow jurisdictional statute rather than on the merits of climate liability, but it adds to the procedural obstacles plaintiffs face in keeping these cases in state court, where their legal theories have the best chance of surviving.