Press Releases
August 3, 2026
WASHINGTON, D.C. — The U.S. Supreme Court should allow the City and County of Boulder, Colorado’s climate deception lawsuit against ExxonMobil and Suncor Energy to keep moving toward trial, a wide range of elected officials, legal scholars, public interest groups, and others argued in amicus briefs filed with the court today.
Boulder is seeking to hold the two major oil companies accountable for concealing the dangers of their fossil fuel products and to make them pay for the resulting local harms. This fall, the justices will hear Exxon and Suncor’s arguments to overturn last year’s Colorado Supreme Court decision that allowed the case to move into discovery.
After Boulder last week filed its final response brief with the Court before oral arguments, a wide range of groups and individuals today filed briefs in support of Boulder’s arguments that 1) its attempts to hold Exxon and Suncor accountable for local harms caused by their climate deception are not preempted by federal law and 2) the U.S. Supreme Court lacks jurisdiction to hear the case before there is a final judgement from Colorado courts.
Among the parties that filed briefs in support of Boulder are:
90 members of the House and Senate, who explained that “The Clean Air Act’s text, structure, and purpose show that Congress has not preempted [Boulder’s] state tort claims” because it “did not address deceptive marketing or sales of fossil fuels at all.”
Attorneys general from 19 states, who wrote that Exxon and Suncor can point to no Constitutional text that preempts Boulder’s case, that “preempting state law because of concerns about a claim’s merits has no place in the structure of our federal system” and that doing so “would permit large tortfeasors to escape state tort liability when their actions cause tangible harm.”
Former Environmental Protection Agency (“EPA”) administrators, officials, and senior career staff: “At no time since the [Clean Air] Act’s enactment in 1970 has it been applied or construed as regulating the fields of truthful advertising or consumer protection that are at issue in this case” and that “the Clean Air Act’s purposes and objectives do not include protecting the fossil fuel energy market.”
Colorado ranchers who “fear that if municipal government keeps absorbing the increasing costs imposed by heat, drought, fires, and flooding, it will not be able to provide the services on which they depend to continue ranching.”
13 federally recognized Indian tribal governments: “Faced with unprecedented threats to their communities from climate disruption, the exercise of this sovereign prerogative is critical for tribes (just as it is for states and local governments) to place the economic burden of the climate crisis—which they cannot afford—upon the responsible parties.”
The Brady Center to Prevent Gun Violence and Giffords Law Center to Prevent Gun Violence, which pointed to the long history of municipalities bringing common law litigation against parties to address local harms that have national, or even international, reach, such as lawsuits against firearms, tobacco, and opioid manufacturers. They wrote: “the Framers of the Constitution expressly entrusted the States—and, through them, their political subdivisions—with primary responsibility for protecting the public welfare” and “tort litigation is an important means through which state and local governments of all political stripes have long exercised that traditional power.”
The Local Government Legal Center, National Association of Counties, National League of Cities, and International Municipal Lawyers Association: “Faced with deceptive and injurious conduct, local governments have the responsibility to take action despite the efforts of wrongdoers to divert and delay … The local government response should not be short-circuited, as the Petitioner oil companies ask of this Court, by a decision that forecloses the day in court that Boulder County and other local governments across the country seek … When other industries have engaged in similar misrepresentations about the safety or healthfulness of their products, no preemptive effect has stopped those lawsuits – and none should here.”
Background on Boulder et al. v. Suncor et al.
Originally filed in 2018, Boulder’s lawsuit seeks to make ExxonMobil and Suncor Energy pay for the costs of local climate damages, arguing that the companies deceived the public about the dangers of their fossil fuel products and continued to produce, market, and sell them at dangerous levels despite knowing the risk.
Boulder’s complaint states clearly that the local governments “are not asking this Court to stop or regulate emissions in Colorado or elsewhere; they ask only that Defendants help remediate the harm caused by their intentional, reckless and negligent conduct, specifically by paying their share of the costs Plaintiffs have incurred and will incur because of Defendants’ contribution to alteration of the climate.”
In May 2025, the Colorado Supreme Court ruled 5-2 that the case could move into discovery and proceed toward trial, upholding a state trial court decision that concluded federal law did not preempt Boulder’s claims. “We reject [Exxon and Suncor’s] contention that Boulder’s action is, in essence, an attempt to regulate GHG emissions and is therefore preempted,” the Colorado Supreme Court found. “As a factual matter, Boulder’s claims do not seek to regulate GHG emissions … Rather, they seek compensation for allegedly tortious conduct."
Like other communities across the country, Boulder is facing staggering costs to protect residents and infrastructure from climate damages. In 2021, more than 1,100 homes and businesses in the county were destroyed in the deadly Marshall Fire, which scientists found was made more destructive because of climate change, and caused more than $2 billion in damages.
Visit here for a deeper explainer about Boulder’s case.
Background on U.S. Climate Accountability Lawsuits Against Big Oil:
Eleven U.S. states — California, Connecticut, Delaware, Hawai`i, Maine, Massachusetts, Michigan, Minnesota, New Jersey, Rhode Island, Vermont — and the District of Columbia, along with dozens of city, county, and tribal governments in California, Colorado, Hawai`i, Illinois, New Jersey, New York, Oregon, Pennsylvania, Washington, and Puerto Rico, have active lawsuits to hold major oil and gas companies accountable for deceiving the public about their products’ role in climate change. These cases collectively represent more than 1 in 4 people living in the United States.
The oil and gas industry and its allies have been lobbying Congress and the Trump administration for more than a year for a legal shield against such cases. Republican lawmakers have introduced bills in the U.S. House and Senate that aim to grant Big Oil companies broad immunity from climate laws and lawsuits, and a growing number of states have passed state-level laws that aim to shield fossil fuel companies from legal accountability. Recent reporting from ProPublica found those bills are "part of a coordinated effort by groups linked to right-wing activist Leonard Leo."