Here the 2nd Circuit relied heavily on a little-known, century-old Supreme Court case called Georgia v. Tennessee Copper Co. The suit began in the early 1900s, when the State of Georgia sued two copper companies in Tennessee for emitting noxious emissions that destroyed plants and crops in Georgia. No less a figure than Justice Oliver Wendell Holmes found the copper companies liable for the nuisance of air pollution and ordered the companies to reduce their emissions. When the companies failed to fully comply, the court set emissions limits, with monitoring requirements and costs divided between the defendants. In other words, the court established the same sort of regulatory regime Congress would introduce 50 years later with the 1970 Clean Air Act.

Today, federal courts dealing with global-warming lawsuits are faced with the same dilemma as the Supreme Court was in Tennessee Copper, only on a much larger scale. Air pollution from one state is causing harm to other states (indeed, to the whole world). Despite the encouraging rulings from the courts of appeals, however, today’s global-warming nuisance suits face an uncertain future. Last month, the 5th Circuit announced a rehearing en banc for the Katrina victims’ lawsuit, meaning that all of the court’s judges will sit and rehear the case. The Alaskan villagers, who lost before the district court, now move to the 9th Circuit Court of Appeals. One or more of these plaintiffs may well wind up before the Supreme Court.

And there a conservative majority may be more sympathetic to the fossil-fuel industry, which argues that the courts should butt out because Washington is doing plenty about global warming. The industry’s Exhibit A is in fact another court case: The Supreme Court’s 2007 ruling in Massachusetts v. EPA, which held that greenhouse gases are air pollutants within the meaning of the Clean Air Act, allowing the EPA to regulate the gases directly.

But the 2nd Circuit in September rejected the argument that this displaced the nuisance suits, noting that the EPA had not yet used the Clean Air Act to regulate greenhouse gases. The court acknowledged that this could change if and when the Obama administration gets moving.

Judge Peter Hall, the author of the 2nd Circuit’s opinion, conceded the same point in a recent speech at Georgetown Law School. The courts would happily get out of the business of hearing nuisance suits about climate change, he said, if the EPA does its job in restricting these emissions-or better yet, if Congress passes a comprehensive climate bill. In the meantime, however, Judge Hall added that judges have the responsibility to take seriously nuisance lawsuits brought by property owners facing strengthening hurricanes and rising sea levels. These lawsuits, he said, probably provide a backstop and “some small impetus” to stonewalling lawmakers. It’s a trade-off: Polluters can either get out of the way of Congress or face the, well, nuisance of lawsuits for decades to come.