Dossier Entry — The Position of Each Party
The state of Vermont says the floods were real, the damage was real, and the companies that extracted and refined the fuels whose emissions contributed to the damage owe a proportional share of the cost.
The American Petroleum Institute, the U.S. Chamber of Commerce, the U.S. Department of Justice, and 24 state attorneys general say the floods were real, the damage was real, and the companies do not owe anything.
This is where the argument now lives. Not in the question of whether the damage occurred. In the question of who, if anyone, can be addressed on the invoice.
On March 30, 2026, U.S. District Judge Mary Kay Lanthier heard oral arguments in the first federal court challenge to a climate superfund law in history, at a courthouse in Rutland, Vermont. She did not rule from the bench. The dossier remains open.
Dossier Entry — The Instrument Under Dispute
Vermont's Climate Superfund Act — Act 122 of 2024, subsequently updated — establishes a cost-recovery procedure. Any entity that extracted fossil fuels or refined crude oil and is accountable for more than 1 billion metric tons of covered greenhouse gas emissions between January 1, 1995, and December 31, 2024, qualifies as a responsible party. Vermont's Agency of Natural Resources will calculate the state's total climate adaptation costs. Each responsible party will be asked to pay a share of those costs in proportion to their share of total covered emissions over the period.
The payment formula is not complicated. It is a ratio. The numerator is the company's historical emissions. The denominator is total covered global emissions from fossil fuels over the same period. Multiply that fraction against Vermont's climate costs, and you have the invoice.
The agency must adopt final rules by January 1, 2028. The state treasurer's cost report is not due until January 2027. As of April 2026, no cost-recovery demand has been issued to any party anywhere in the United States under any climate superfund law.
BUREAU NOTE: For classification purposes, this dispute is unusual. The billing department has not opened. The cost report has not been filed. The rules have not been adopted. The invoice has not been prepared, addressed, or sent. The litigation that will determine whether the invoice is constitutional was filed in January 2025 and argued before a federal judge in March 2026. The Bureau's records contain no prior instance of a receivable being litigated before the receivable exists.
Dossier Entry — The Basis for the Calculation
The methodology Vermont's act requires is not speculative. Attribution science — the peer-reviewed discipline of tracing physical climate outcomes to specific emission sources — has been developing the necessary tools for years, and they have recently arrived in print.
In April 2025, a study published in the journal Nature established an end-to-end framework for exactly this calculation. Researchers used emissions data from 111 of the world's largest fossil fuel and cement producers — the Carbon Majors database — and applied peer-reviewed attribution methods to link those companies' cumulative emissions to specific economic losses from extreme heat between 1991 and 2020. The result: $28 trillion in heat-related economic damage attributable to those 111 companies. Of that total, $9 trillion — approximately 32 percent — is traceable to five companies: BP, ExxonMobil, Chevron, Saudi Aramco, and Gazprom.
Emissions linked to Chevron alone, the study found, are attributable to between $791 billion and $3.6 trillion in heat-related losses over the period, disproportionately concentrated in tropical regions that contributed least to the warming.
Vermont's damage claims total $500 million. The study documents $28 trillion. Vermont is, in accounting terms, requesting approximately 0.002 percent of the calculated total. The challengers describe this as overreach.
Vermont's payment formula does not depend on this particular study. But the study demonstrates that the science underlying the billing methodology is published, peer-reviewed, and specific enough to name a company, name a figure, and describe which part of the world absorbed the cost.
The invoice has been drafted in science. The law creates the administrative mechanism to make it a legal document.
Dossier Entry — The Damage That Prompted the Invoice
Vermont did not pass a climate superfund act because of an abstract policy preference. In July 2023, flooding caused by extreme rainfall inundated Montpelier, Barre, and dozens of smaller communities across the state. Federal Emergency Management Agency records show that Vermonters submitted $500 million in damage claims — more than double the amount generated by Tropical Storm Irene in 2011.
The flooding was the proximate cause of the legislation. Vermont lawmakers passed the Climate Superfund Act in May 2024. The stated purpose was to recover a portion of those costs from the entities whose products' emissions contributed to the conditions that made such flooding more severe and more frequent.
The law is modeled on the federal Superfund statute — the Comprehensive Environmental Response, Compensation, and Liability Act, known as CERCLA — which imposed retroactive strict liability on companies that contributed to toxic waste contamination, regardless of whether their conduct was considered wrongful at the time. Federal courts upheld CERCLA's retroactive liability against due process challenges. Vermont's architects chose the same architecture deliberately.
BUREAU NOTE: A confession, filed for the record: the Bureau initially expected the legal challenge to include an argument that climate change is not real, or that Vermont's floods were not connected to it. No such argument appears in the challengers' filings. The U.S. Department of Justice argues preemption, commerce clause violations, due process, and federal foreign affairs authority. The American Petroleum Institute argues that Vermont cannot subject global energy production to Vermont law. None of them argue the flooding did not happen or that emissions did not contribute to it. The Bureau notes that this represents a material change from the previous decade of argumentation, and that the change has not been widely acknowledged as the concession it is.
Dossier Entry — The Challengers' Filed Position
The legal challenge has four principal architects.
The U.S. Chamber of Commerce and the American Petroleum Institute filed suit in January 2025, calling the law unconstitutional and a violation of federal authority. The Trump administration added its own complaint on May 1, 2025, in nearly identical language — arguing that Vermont's act is preempted by the Clean Air Act, violates the interstate and foreign commerce clauses, violates due process, and encroaches on the federal government's exclusive authority over foreign affairs. Twenty-four Republican state attorneys general, led by West Virginia, joined as intervenors.
The industry filed. The administration filed. Twenty-four states filed. The invoice had not.
The DOJ's core argument, stated plainly by its attorney at the March 30 hearing: Vermont is attempting to subject global energy production activity to Vermont law, and this brazenly disregards the constitutional division of power between the federal government and the states.
Vermont's attorney general responded with equal plainness: as a sovereign state, Vermont exercises traditional state authority, and the Climate Superfund Act operates squarely within it.
The American Petroleum Institute separately declared, heading into 2026, that fighting climate liability lawsuits was one of its top legislative priorities. The industry is also lobbying Congress for a liability shield modeled on a 2005 statute that protects gun manufacturers from lawsuits.
Vermont is not the only defendant. New York Governor Kathy Hochul signed an equivalent law on December 26, 2024, establishing a target of $75 billion over 25 years from fossil fuel companies based on their proportional share of global emissions between 2000 and 2024. The DOJ filed a nearly identical complaint against New York. Two states are now in federal court defending the same theory of liability at the same stage of the same billing process — which is to say, before any bill has been produced.
Dossier Entry — The Current Status of the Invoice
The Bureau closes this dossier entry with the one fact that no document in the record disputes.
Vermont has not issued a cost-recovery demand. New York has not issued a cost-recovery demand. No climate superfund law anywhere in the United States has resulted in a single dollar being collected or a single invoice being sent to a fossil fuel company. Vermont's cost report will not even be completed until January 2027. The final rules that would govern the demands are not due until January 2028. The demands themselves would follow the rules.
What has been issued is a law describing how the invoice will eventually be calculated. What has been filed, in response, is a federal lawsuit arguing that the invoice, once calculated, would be unconstitutional.
The legal question before Judge Lanthier — and before the federal courts that will follow this wherever it goes — is whether a state may construct an accounts-receivable function for climate damage at all. Whether the methodology works. Whether the proportional attribution is legally cognizable. Whether the constitutional architecture holds.
The underlying question, which no party to the litigation is asking, is a simpler one: if the damage is real, and the emissions that contributed to it are documented, and the proportion attributable to each company can be calculated from peer-reviewed science, and no party disputes any of that — then what exactly is the argument that the invoice should not exist?
The record, for now, is silent on that point. The silence is at least more interesting than the answer the industry was giving a decade ago.
The Bureau of Climate Accounts Receivable has filed this dossier as a receivable of its own — a document about a document that does not yet exist, disputing a process that has not yet produced a result. The Bureau has been here before. The invoice always takes longer than the damage.