A polluter emits something that hurts people in a community. These people get together and sue the polluter. Courts then side with the victims under the common-law tort of nuisance, and award damages (or an injunction shutting down the polluter). Before the era of modern environmental regulation, all pollution-related disputes were solved this way.

Regulation has made environmental nuisance suits much less common and less necessary, but they have not disappeared completely. The problems presented by climate change are broadly similar—polluters emit greenhouse gases (GHGs) that ultimately cause harm. In the absence of government regulation of GHGs, can nuisance suits be used to force polluters to reduce emissions or to compensate for adaptation costs?

Suits seeking answers to these questions exist and are making their way through courts now. Some of them have made headlines, such as that filed by Kivalina, Alaska—a town on a barrier island formerly protected by Arctic sea ice, but which now faces increasing erosion. The New York Times reported on the case in an article that also discusses some similar cases, including perhaps the most widely-reported, Connecticut v. AEP.  In that case a group of states and private conservationist landowners are suing power companies under a similar nuisance theory.

So are these cases going to end up with major judgments that effectively set policy? Is big tobacco going to be the model for redressing harms from climate change? If tobacco is the model, I wouldn’t get your hopes up. But it is likely that these lawsuits will end up playing a big role in the policy process.

Despite the relatively high-profile coverage of some of the cases, there is not much for advocates of GHG regulation to be excited about. No climate nuisance case (that I know of) has been successful. The biggest “victory” so far has been in Connecticut v. AEP. Still in that case, the Second Circuit simply reversed a lower court’s comprehensive dismissal of the plaintiffs’ claims.  The appellate court ruled that courts could decide the case in principle (it was not a “political question”) and that the states did have standing to sue over climate harms. This says almost nothing about the plaintiffs’ likelihood of success on the merits of the case. Causation and damages will be big hurdles for the states when the lower court reaches the merits.

It’s also possible that EPA action could preempt these suits. The Second Circuit ruled that the lack of EPA GHG regulation left the field open for nuisance suits, but strongly implied that any EPA regulation would preempt them. Connecticut was decided just before the EPA released its endangerment finding for mobile sources in December. It’s likely that any nuisance suit aimed at auto manufacturers would fail for preemption reasons now that the EPA has committed to regulating mobile-source GHGs. If the EPA, as many expect, moves to regulate stationary-source GHGs, then Connecticut itself would presumably be preempted also.

This link between EPA regulation and nuisance lawsuits, however, creates a lever through which those suits might still have a big effect on how climate policy gets made—as Jonathan Zasloff at UCLA has pointed out. As nuisance suits proceed, they will put increasing pressure on the EPA to regulate to preempt them since regulation is generally perceived as a superior approach (especially by the EPA itself, one expects). Both nuisance suits and EPA regulation put pressure on Congress to enact climate legislation.

Opponents of action on climate are effectively stuck playing whack-a-mole - if they succeed in blocking action in Congress and through the EPA (possibly by getting a Murkowski-style resolution passed), nuisance suits will proceed with unpredictable results. If they quietly let the EPA regulate, those suits go away, along with a lot of pressure on Congress. But Clean Air Act regulation is a bitter pill to swallow. The most likely long-term result seems to be congressional action—opponents can’t push for inaction forever with the twin threats of EPA regulation and nuisance suits.

In short, nuisance suits make business-as-usual on climate much less likely, even if they are not themselves very likely to succeed. This should be cause for some optimism about the long term if you are frustrated by the current inability of Congress to enact climate legislation.

Nathan Richardson is a Visiting Scholar at RFF.