Last week, a federal judge in Rhode Island ended a challenge by General Motors, Chrysler and other automobile trade groups attempting to block Rhode Island’s vehicle greenhouse gas(GHG) emission standards. The automobile industry sought a declaration that the Rhode Island regulations were preempted by less-stringent standards set by the Environmental Protection Agency (EPA) under the federal Clean Air Act (CAA). The district court judge found that the issues had already been decided in two previous cases in Vermont and California and issued a judgment against the automobile manufacturers and associations.

The automobile industry’s objection to Rhode Island’s regulations was largely symbolic at present. The CAA allows states to set stricter vehicle GHG emission standards only if California first obtains a waiver from the EPA to do so. California applied for a waiver in 2005 and was denied. For as long as California does not hold a waiver, the Rhode Island regulations remain unenforceable.

As a result, the court's decision has no immediate impact upon the state of vehicle GHG emissions. The situation may change, however, with the incoming administration. During his campaign, President-elect Obama indicated his intent to approve the California waiver. If he does, the Rhode Island decision could allow the largely equivalent Rhode Island regulations to become effective.