A recent federal court decision ruling that California's Low Carbon Fuel Standard (LCFS) violates the dormant Commerce Clause of the U.S. Constitution highlights an issue that has much broader implications than the setback it creates for that state's plan for shrinking its net carbon emissions in the transportation sector. In finding that California's preferential treatment for fuels with low full life-cycle "carbon intensity" (all carbon emitted from extraction and refinement to point of sale) discriminates against out-of-state fuel suppliers, the court's decision in Rocky Mountain Farmers Union v. Goldstene has underscored the need for balancing legitimate anti-protectionist concerns with the ability of governments to reduce the carbon footprints of states, regions, or countries.

In a ruling yesterday, a panel of the 2^nd Circuit Court of Appeals handed down a unanimous victory for the plaintiffs in Connectituct v. American Electric Power, a case brought by a coalition of states and local governments against a number of large power plants. The case, originally argued in 2006, had been dismissed by the lower court on the grounds that it represented a "non-justiciable political question." Yesterday's ruling, decided by two judges (the original third Judge on the panel, Sonia Sotomayor, left the 2^nd Circuit for the Supreme Court) overturned that decision, stating that:

“Nowhere in their complaints do plaintiffs ask the court to fashion a comprehensive and far-reaching solution to global climate change, a task that arguably falls within the purview of the political branches. Instead, they seek to limit emissions from six domestic coal-fired electricity plants on the ground that such emissions constitute a public nuisance that they allege has caused, is causing and will continue to cause them injury.”

After adressing the question of the lower court's holding, the panel ruled that the suit could continue, finding that a common-law claim of "public nuisance" regarding greenhouse gasses was not preempted by federal law and articulating a role for federal courts in the current climate battle.

“It may happen that new federal laws and new federal regulations may in time pre-empt the field of federal common law of nuisance. But until that comes to pass, federal courts will be empowered to appraise the equities of the suits alleging creation of a public nuisance” by greenhouse gases.

This ruling means that courts could end up having a significant role in determining how greenhouse gasses are emitted and controlled—at least in the event that Congress fails to act on its own emissions control program.

State of Connecticut v. American Electric Power Co. (PDF) [2^nd Circuit Court of Appeals]