Honolulu Denial to Boulder Argument: Climate Damage Suits Against Oil Companies Reach the Supreme Court

On January 13, 2025, the U.S. Supreme Court declined to hear appeals from oil and gas companies that wanted climate-damage lawsuits pulled out of state court. By denying review in Sunoco LP v. Honolulu and Shell PLC v. Honolulu, the justices left standing a 2023 Hawaii Supreme Court ruling and let the City and County of Honolulu keep suing in its own courts. Justice Samuel Alito did not participate. No justice publicly noted a dissent from the denial.

A denial of certiorari is not a ruling on the merits. The Court did not find the companies liable and did not bless the plaintiffs’ theory that fossil-fuel marketing is a state-law fraud with a climate-sized bill attached. The only question at that stage was jurisdictional: whether these claims belong in state court or must be heard in federal court. By stepping aside, the justices allowed the litigation to proceed without deciding who owes what.

That pause did not last. On February 23, 2026, the same Court agreed to hear Suncor Energy Inc. v. County Commissioners of Boulder County, the Colorado companion that raises the preemption fight the Honolulu petitions had not forced to a decision. Oral argument is set for Monday, October 5, 2026, as the first case of the new term. The AEGIS Alliance now treats the January 2025 order as chapter one of a federalism fight that the justices finally agreed to referee.

What Honolulu Opened

Honolulu’s suit is part of a wave that legal trackers date to the years after the 2015 Paris Agreement. Surveys have counted more than 200 climate-related cases against fossil-fuel companies, a large share of them filed in a short span, many of them in U.S. state courts. Plaintiffs say producers misled the public about the role of their products in warming, and that cities now pay for sea walls, wildfire response, storm damage, and public-health costs those companies should share. Defendants named across the docket include Sunoco, Shell, Chevron, ExxonMobil, BP, and ConocoPhillips.

The companies answer that greenhouse-gas emissions are a national and international problem that federal law already occupies. They want the cases in federal court, where they have won dismissals, or out of court altogether. They describe municipal suits as an attempt to set energy policy through tort law, one county at a time. Industry allies at the American Enterprise Institute called the Honolulu denial a gift to activists who would rather litigate than legislate. Honolulu’s chief resilience officer, Ben Sullivan, called it a way to keep taxpayers from eating the whole bill.

The Biden administration, then still in office, had urged the Court to leave the cases in state court. That recommendation aged quickly. After President Trump returned, an April 2025 executive order framed state climate suits and “climate Superfund” laws as obstacles to energy policy. The Justice Department filed preemptive actions against states including Hawaii, Michigan, New York, and Vermont. The legal theory flipped with the election. The underlying complaints did not.

Boulder Moves the Question Onto the Merits Calendar

Boulder County and the City of Boulder sued ExxonMobil and Suncor entities in April 2018. They argue the companies “intentionally misled the public” about climate risk and that Colorado communities now pay more for extreme weather, including fire. On May 12, 2025, the Colorado Supreme Court ruled 5-2 that the suit could proceed. The companies petitioned the U.S. Supreme Court. This time the justices took the case.

The Trump administration filed a brief urging reversal and warning that if Boulder can sue, “every locality in the country could sue essentially anyone in the world for contributing to global climate change.” A group of 26 states with Republican attorneys general, led by Alabama’s Steve Marshall, said cities have no business hauling out-of-state producers into local court on a planetary theory. ExxonMobil’s line has been consistent: climate policy should not be set through fragmented state-court actions.

Boulder’s lawyers answer that there is no constitutional bar to a state addressing in-state harm caused by out-of-state conduct, and they analogize to negligent automobile design and asbestos. Some observers note that the companies’ preemption argument may have been complicated by the Trump EPA’s move against the “endangerment finding,” the scientific determination that underpinned federal greenhouse-gas rules. If the federal scheme is being dismantled, the claim that a robust federal program displaces state tort law gets harder to sell. That is a legal irony, not a science brief.

SCOTUSblog’s docket lists the case as No. 25-170 and confirms the October 5, 2026 argument date. Boulder County’s own statement after the grant of review treated the moment as a test of whether local governments may seek damages at all.

Federalism Dressed as Climate Policy

Strip the carbon out of the captions and this is still a Supremacy Clause case. Article VI says federal law is supreme. The companies say emissions regulation is federal. The cities say consumer protection, public nuisance, and fraud are state tools they have always used when a product injures people inside the county line. Both sides are talking about power. Climate is the harm that makes the power fight urgent.

If the Court sides with Suncor and Exxon, a decade of municipal complaints could be funneled into federal forums that have already been hostile, or shut down as preempted. If the Court sides with Boulder, the Honolulu denial becomes a green light rather than a shrug, and more counties will file. Either result will be sold as climate policy. It will actually be a decision about which courthouse gets to hear the evidence.

Wildfire seasons in the West give the plaintiffs their pictures. Price shocks and energy-security speeches give the defendants theirs. Neither picture answers the doctrinal question. The justices can resolve the case on jurisdiction and never reach whether a jury should ever see a marketing memo from the 1980s. They can also write a broad preemption rule that ends the genre. Argument in the first week of the term suggests they know the file is not small.

How The AEGIS Alliance Reads the Arc

The January 2025 Honolulu order was easy to misread as a victory parade. It was a traffic signal. The Boulder grant is the intersection. Between those dates the executive branch changed sides, state attorneys general picked teams, and the EPA’s own climate authority became a moving target. Readers who want the energy-and-environment desk around this fight should see environment coverage and what other countries do with the physical leftovers of the energy transition.

Related reporting on this site also includes the older science files on science news and the politics of who pays when a commons fails. The AEGIS Alliance will not pretend a cert denial was a liability finding. It will not pretend an October argument is a verdict. It will keep the sequence straight: Honolulu lived, Boulder was taken, and the first Monday in October 2026 is when the Court has to say whether a county may put an oil company in the dock for a warmer century.

For the running permalink on this case, stay with the climate-suits file. For the Court as an institution on this desk, see other Supreme Court coverage and U.S. news. The companies wanted a federal shield. The cities wanted a state courtroom. The justices have now scheduled the argument that decides which request survives.