In Vermont, courts weigh who should pay for the cost of climate change

“Vermont is ground zero for this litigation,” said Patrick Parenteau, an environmental law expert at Vermont Law and Graduate School.

Last May, Vermont became the first state in the country to enact a climate superfund law after a veto-proof majority of lawmakers passed the legislation. A refrain of the law’s supporters: “If you make a mess, you clean it up.”

The state law is modeled after the federal Superfund program, which has required companies to pay for the cleanup of hazardous waste sites since the 1980s. Oil and gas companies are historically among the largest emitters of carbon dioxide and methane emissions that drive climate change.

“This is not a campaign of vengeance, it’s the pursuit of basic fairness,” said Paul Burns, the executive director of Vermont Public Interest Research Group, an environmental advocacy organization that pushed for the bill. “It’s the only way a small state like ours can hope to pay for the damages that will come.”

Governor Phil Scott, a Republican, allowed the bill to become law without his signature. In a letter to lawmakers, he acknowledged the desire to seek funding to mitigate the effects of climate change. But he warned that the state had not allocated enough money to allow for “positioning ourselves for success” against legal challenges.

“Taking on ‘Big Oil’ should not be taken lightly,” he wrote, adding that failure in Vermont could hurt similar efforts in other states.

The US Chamber of Commerce and American Petroleum Institute, an industry group, filed a lawsuit challenging the policy last December. Two dozen states led by West Virginia’s attorney general joined the case in May.

Daryl Joseffer, chief counsel at the litigation arm of the US Chamber of Commerce, said in a statement that Vermont had exceeded its authority on an issue “best left to the federal government.”

Charlotte Law, a spokeswoman for the American Petroleum Institute, said the law would set a “dangerous new legal precedent” against companies that were “meeting demand for affordable, reliable energy.”

The Vermont superfund law requires major fossil fuel companies to pay for their contribution to climate disasters, such as the severe flooding in 2023 and 2024 that caused over a billion dollars in damage.

The state expects to determine the financial penalty by mid-2027, with the money going toward climate adaptation projects. In New York, the second and only other state with a climate superfund law, officials are seeking $75 billion to help pay for infrastructure projects like coastal wetlands restoration, energy-efficient cooling systems, and responding to extreme weather events.

Cost calculations are determined using the growing field of attribution science, which investigates links between climate change and specific extreme weather events. New advances have enabled scientists to build out frameworks that connect particular sets of emissions to climate damage. Even a few years ago, these calculations would’ve been much more difficult.

A study published in April by researchers at Dartmouth College and Indiana University that refined this approach found that Chevron’s emissions very likely caused up to $3.6 trillion in heat-related losses around the globe. Justin Mankin, a co-author and Dartmouth associate professor, told lawmakers at a hearing in Montpelier that scientists can now confidently quantify the harms linked to one emitter.

At the start of May, the US Department of Justice joined the legal fight against the superfund laws, filing complaints against Vermont and New York. Lawyers for the Trump administration argued that Vermont’s law attempts to usurp power from the federal government, which it claims has sole responsibility for regulating greenhouse gas emissions. The Justice Department also alleged that the law would hike energy costs for consumers across the country.

The complaint called Vermont’s law a “brazen attempt” to “force citizens of other States and nations to foot the bill for Vermont’s infrastructure wish list.”

A group of economists, including Joseph Stiglitz, a Nobel Prize winner at Columbia University, filed a brief describing the government’s claims that a financial penalty would cause economic harm to oil and gas companies as “implausible and hyperbolic.” One-time costs based on past pollution, the economists wrote, do not drive up future oil and gas costs.

Others argue that the federal government does not have sole jurisdiction to address climate pollution.

Kate Sinding Daly, senior vice president for law and policy at the Conservation Law Foundation, said the administration’s push to eliminate the Environmental Protection Agency’s endangerment finding, which underpins federal responsibility for regulating greenhouse gas emissions, could hurt its case. The foundation has joined Vermont as a defendant in both lawsuits.

“That is right at the crux of the hypocrisy,” she said. “They are simultaneously looking to undo science-based measures that acknowledge climate change is real and then at the same time say that states can’t do anything about climate change.”

Legal experts said it could take years for the lawsuits to resolve, and the challenges could make it to the Supreme Court. In Maine and Massachusetts, where superfund legislation is pending, lawmakers said they are pressing forward with bills despite the legal challenges to Vermont’s law.

Massachusetts State Senator Jamie Eldridge said he is confident the legislation he introduced is on solid legal footing. He added that he’s seen an increase in support among local officials who tell him, “It’s great that Massachusetts has passed all these climate laws, but we need funding for projects in our communities.”

In the third climate-related lawsuit, with Vermont as the plaintiff, the state has taken several major oil and gas companies, including Exxon Mobil, to court. Vermont alleges that the companies took “extraordinary steps” to deceive customers about the link between their products and climate change. It is calling on the companies to give up profits they made in Vermont from unlawful practices and pay further penalties for violating the Vermont Consumer Protection Act.

Michael Gerrard, the director of Columbia’s Sabin Center for Climate Change Law, said Vermont’s case is one of about 30 across the country that have been brought since the late 2010s alleging that oil companies put out false information about the impact of their products. Vermont’s lawsuit was filed in 2021.

None of these cases has yet to go to trial, Gerrard said, except for a narrower case in New York that alleged Exxon Mobil violated a state law against shareholder fraud. The state lost that case.

Vermont notched a legal victory in December when a judge rejected the companies’ requests to dismiss the lawsuit, moving the case a step closer toward going to trial.

Kate Selig can be reached at kate.selig@globe.com. Follow her on X @kate_selig.