The U.S. Supreme Court has opened its new term with a case out of Colorado that could decide the fate of climate litigation nationwide: whether local governments can sue oil and gas companies in state courts for damages tied to global warming, or whether such claims must be handled exclusively through federal law and federal regulators.

The case centers on a lawsuit filed by a Colorado county against an oil refinery, which the county accuses of exacerbating climate change and, in turn, causing measurable local harm, from infrastructure damage to increased wildfire and flood risk. The justices' eventual ruling will determine not just the outcome of this single dispute, but whether a wave of similar suits filed by cities, counties, and states against fossil fuel companies can move forward at all.

A Test Case With National Stakes

Over the past several years, more than two dozen state and local governments, from California to Rhode Island to Hawaii, have filed lawsuits arguing that oil and gas companies knew for decades about the climate risks of their products yet concealed that knowledge from the public, leaving local taxpayers to foot the bill for climate-related damage. These cases have largely been framed under state tort law, including claims of nuisance, trespass, and deceptive trade practices, rather than federal environmental statutes.

Energy companies have fought hard to move these cases out of state courts and into the federal system, where they argue that claims touching on interstate emissions and energy policy should be governed by the federal Clean Air Act rather than a patchwork of state liability rules. The Colorado case gives the Supreme Court an opportunity to settle that jurisdictional question once and for all.

The ruling could determine whether similar cases can move forward.

If the court sides with the county, it would affirm that state courts have the authority to hear climate damage claims rooted in state law, potentially opening the door for dozens of pending and future lawsuits to proceed toward trial, discovery, and the kind of evidence fights that have already proven costly and reputationally damaging for energy companies in other contexts, such as tobacco and opioid litigation.

If the court sides with the refinery, it could effectively shut down this entire category of litigation, forcing local governments to seek redress, if any, through federal regulatory channels or Congress rather than the courts.

A Long History of Stalled Climate Policy

The case arrives against the backdrop of decades of halting international and domestic efforts to curb greenhouse gas emissions. Scientific consensus on human-caused climate change solidified in the 1990s, culminating in the 1992 Earth Summit in Rio de Janeiro, where 178 nations pledged to address the crisis, and the 1997 Kyoto Protocol, which set binding targets for industrialized nations to cut emissions.

The United States, however, never ratified Kyoto. President George W. Bush withdrew the country from the agreement in 2001, citing economic concerns, even though the U.S. at the time accounted for roughly a quarter of global greenhouse gas emissions despite having only about 6 percent of the world's population. Domestic legislative efforts have fared little better: a 1993 Clinton administration proposal to tax energy consumption was rejected by the Senate.

With binding international agreements and federal legislation proving elusive, climate advocates and local governments have increasingly turned to the courts as a venue for accountability, arguing that if political institutions will not act, judges might force companies to internalize the costs of the damage their products have caused.

Why Local Governments Are Suing

The logic behind the Colorado county's suit, and others like it, mirrors arguments climatologists have made for years: that the costs of climate change (extreme heat, drought, flooding, and storm damage) fall disproportionately on local communities that had little role in producing the emissions responsible for the harm. Researchers have noted that poorer regions and communities often bear the brunt of climate impacts despite contributing the least to the problem, a dynamic now playing out at the municipal level in the United States as counties absorb the costs of climate adaptation and disaster recovery.

For Colorado and other plaintiffs, the lawsuits are, in effect, an attempt to shift those costs back onto the companies whose products are most closely linked to the emissions driving the damage, much as lawsuits against tobacco and pharmaceutical companies sought to recover public health costs decades after scientific consensus on the harms had emerged.

What Comes Next

A ruling against the refinery's jurisdictional challenge would not resolve the underlying question of liability, but it would clear a major procedural hurdle that has stalled similar cases for years as they wind through appeals over where, exactly, they can be heard. A ruling in the company's favor could effectively end the strategy nationwide, pushing climate accountability advocates back toward Congress and federal agencies, bodies that have historically struggled to reach consensus on climate policy.

Legal observers say the case is among the most consequential climate-related matters to reach the high court in years, not because it will decide whether climate change is real or man-made, a question the scientific community settled decades ago, but because it will determine who, if anyone, can be held financially accountable for its effects in an American courtroom.