For over a year, more than a dozen state and local governments have been suing ExxonMobil, Shell, and other fossil fuel companies over alleged damages associated with global warming. So far, they haven’t been successful, but they are pressing forward on a new approach relying on common law that could eventually prevail.  In a discussion sponsored by the Federalist Society, legal scholars debated the common law legal theories behind the suits, the role of the various branches of government and the applicability of the common law theory of nuisance.

These climate change lawsuits have all been structured around variations of the common law theory of nuisance which, their advocates argue, gives state and local governments the ability to sue energy companies for damages associated with their conduct. In this case, that would be the sale of the fossil fuels that consumers later burned, exacerbating the harms of global warming.

According to the academics at the Federalist Society, this is a novel — though flawed — legal approach.

For one thing, the theory of public nuisance remains relatively undefined. “Public nuisance itself as a doctrine has never had a well developed definition,” explains Prof. Donald Kochan, associate dean of research and faculty development at Chapman University. “It has never been robust in the common law, which we should keep in mind when a non-robust standard in the common law is being asked to encompass these unprecedented claims.”

The cases have relied on the common law to fill in for a space where, the plaintiffs argue, the federal government has not exercised its regulatory authority. The common law theories they invoke have generally been applied to specific harms with identifiable contributors. However, the current lawsuits have attempted to use them to go after the companies which sold oil and gas, rather than the consumers who purchased and burned the fuels.

This is an expansion of the legal doctrine that says that liability falls to the person responsible for the action itself, in this case, the end consumer who burned the fossil fuels. Trying to use the common law definition of liability to sue energy companies takes the law in a new direction.

“There was a settled expectation that this was a legit business and now you are trying to rewrite history,” agreed Kochan.

New cases are trying to trump up the wrongful conduct element of a negligence suit, but in the end, the issue boils down to allegations that the companies knew about climate change and continued to sell fossil fuels rather than facilitate the transition to a renewable economy. Phil Goldberg, director of the Progressive Policy Institute Center for Civil Justice and managing partner at Shook, Hardy & Bacon, believes these lawsuits are purely symbolic in nature, meant more to appeal to media attention than to address the harms of global warming.

“The pleadings were intentionally written like press releases,” he said.

He wonders if the mere act of selling a gallon of gasoline is necessarily a tort. So far, courts have not deemed purchasing fuel to be an unreasonable interference of a public rights. This mean that one of the foundations of the public nuisance suit, at the least, rests on untested legal grounds.

Before the details of public nuisance can be debated, however, the court must first decide if the common law standard is in fact appropriate. And in California, climate lawsuits have been stalled by a debate over whether state or federal courts have jurisdiction.

The legal theory of displacement stipulates that if the federal government, or a federal agency, regulates a particular issue, the courts are pushed out. This pushing out would also apply to the common law. Since the federal government, through the Environmental Protection Agency, has been regulating air pollution since the 1970s, an argument could be made that regulation of carbon dioxide emissions and their effects is bound by federal legislation and not common law.

However, since the Clean Power Plan has been stayed by federal court, the issue becomes more complicated. For instance, if Trump were to repeal the Clean Power Plan, it could reopen legal space for states to regulate the issue.

“If Trump leaves a gap, does that make some of the claims of the common law active again, since they are no longer displaced by the EPA?” says Prof. Steven Ferrey of the Suffolk University Law School.

The underlying uncertainty of the common law doctrine shows the key gamble of the suits. In filing them, environmentalists are betting that judges will agree with their interpretation of the evidence supporting man-made global warming and the steps that should be taken to combat it.

As one of the speakers reminded the group, this is far from certain and the cases could end up backfiring on environmentalists.

“What if these courts decided to rule that climate change was fake, that climate change was not real. Would we trust judges to be making that determination?” asked Kochan. “We would close out the political debate by making a political decision that we are supposed to respect somehow, [that] there is no climate science that can justify regulation. If that were the case, then people wouldn’t be trusting judges. Yet that is a perfectly possible outcome when you put things in the hands of judges.”

The climate change cases are, so far, a large uncertainty. While they could cost oil companies hundreds of millions of dollars, they could also close the door on climate litigation by ruling against environmentalists. Right now they may be another example of the adage: Good cases make bad law.

Follow Erin on Twitter.