Mountain States Legal Foundation (MSLF) has filed an amicus brief in a case to support the premise that all Americans—rather than just a few people in Boulder County, Colorado—should have a say in whether and how the Nation makes laws to address worldwide greenhouse gas emissions. In County Commissioners of Boulder County v. Suncor Energy USA, Inc., a group of officials in Boulder, Colorado, has sued two energy companies, Suncor and Exxon, so that the officials can set nationwide climate policy through the courts rather than let national democracy work. It is unclear why the Boulder officials singled out these two companies as the entities allegedly responsible for Boulder’s supposed injuries, and why these officials think that they should be allowed to set climate policy for the entire Nation rather than let elected federal Legislators do that.
This lawsuit strikes at the heart of how the United States addresses national and global challenges. And the stakes in this case are high not only for the two energy companies, but for everyone in this Nation who appreciates the system of governance set up in our Constitution.
Case Summary
The legal battle began in 2018 when the Boulder, Colorado, officials sued Suncor and Exxon, alleging that the companies had not adequately warned the public about fossil fuel consumption and its role in global warming. Boulder’s lawsuit did not simply seek financial damages for local environmental harm—it went further, arguing that these energy companies should be held responsible for the supposed broader impacts of climate change.
The plaintiffs’ legal theories are complex, but the best we can distill them is this: they say that these two energy companies contribute at least something to worldwide greenhouse gas emissions, those worldwide greenhouse gas emissions in some way also harm Boulder, Colorado, and that the two energy companies are liable not so much for the alleged money Boulder thinks it will have to spend to address climate-related damages, but for not commercially advertising that energy production might cause climate changes. It is a radical theory, and it is completely unmoored from the law.
In effect, these local officials really intend to set nationwide climate policy. But as a Nation, we have embraced democratic elections for federal representatives to handle issues like this. We did not as a Nation nominate a few Boulder, Colorado officials to decide national policy.
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This Isn’t an Area for State Courts
The U.S. Supreme Court has said that Congress can set air-pollution policies for the Nation, and that Congress has done that in the Clean Air Act. The Act, for example, displaces older legal theories like “nuisance” for addressing supposed harms that can be traced to emissions into the air.
The Boulder officials want a way around the U.S. Supreme Court’s precedent, asserting that local entities can set nationwide policy if they dress their intentions up as local “tort” law. This is where MSLF’s amicus brief comes into play. Representing Professor Richard Epstein, a scholar of tort law at NYU, and Professor John Yoo, an expert in public law at Berkeley, MSLF’s brief takes a clear stance: Boulder’s lawsuit is an inappropriate attempt to use state tort law to regulate a national issue. MSLF argues that if climate change is inflicting harmful effects nationwide, then the nation should decide how to address it.
Federal legislation often has its own flaws, and we at MSLF certainly are not advocating for a broader, more aggressive and intrusive “administrative state.” But legal precedent and common-sense dictate that if the Nation wants to address the supposed harmful effects of climate change, then the Nation as a whole should figure that out—it’s not a question that a few officials in Boulder, Colorado, should get to answer for the rest of the Country.
We argue that the Boulder County Court mistakenly allowed the officials’ case against two energy companies seeking relief for worldwide climate change. Boulder officials in a Boulder County court should not be allowed to set national policy. And in letting the case go forward, the Boulder County Court wrongly embraced infirm, novel legal theories that are contrary to law and make no sense.
What makes this case particularly dangerous—going beyond the idea that a few Boulder, Colorado officials could set national policy—is that it would pose litigation risks to every producer, user, and even consumer of fossil fuels, and every entity in the supply chain in between, who could become the next defendant in a suit for contributing to energy use, that allegedly increases greenhouses gases, allegedly raises global temperatures, and then allegedly causes climate change, which in turn allegedly harms Boulder, Colorado. Worse still, there are thousands of different counties throughout the United States, each of which could bring a copycat complaint that could plunge any of a thousand energy companies, other types of companies and even energy-using individuals into the same morass.
What’s at Stake?
MSLF and its clients for this matter, Professors Epstein and Yoo, have vested interests in ensuring that the law is applied properly. As legal scholars, the Professors understand the potential ramifications of allowing state courts to reshape tort law to accommodate novel, infirm theories of liability as a way to set nationwide precedent. For them—and for MSLF—this case is about ensuring that established legal principles are not undermined by a desire to achieve political outcomes through litigation.
The Colorado Supreme Court’s decision in this case will have far-reaching consequences. If the court upholds the lower court’s ruling, energy producers and everyone who uses energy will unfortunately be held accountable for acts that aren’t in any way directly attributable to them. But if the court agrees with MSLF and the Professors, then it will reject the Boulder officials’ attempt to set national policy, which should be addressed through the federal legislative process rather than a courtroom in Boulder.
Case Timeline:
September 18, 2024: MSLF, on behalf of Professor Richard Epstein and Professor John Yoo, files amicus brief in support of defendants/petitioners.
September 11, 2025: MSLF, on behalf of Professor Richard Epstein and Professor John Yoo, files amicus brief in support of the petition for certiorari.
