United States v. California Air Resources Board

The United States and the U.S. Department of Transportation filed a lawsuit in the federal district court for the Eastern District of California alleging that the California Air Resources Board’s standards for tailpipe carbon dioxide emissions from light-duty vehicles and requirements for zero emission vehicles (ZEVs) in manufacturers’ fleets (“ZEV mandates”) are related to fuel economy standards and are therefore preempted by the Energy Policy and Conservation Act (EPCA). The complaint alleged that “tailpipe CO2 emissions and fuel economy are two sides of the coin” because “[r]educing tailpipe CO2 emissions from current internal combustion automobiles depends upon reducing fuel consumption, and thus, increasing fuel economy.” The complaint also alleged that CARB’s ZEV mandates are related to fuel economy standards because “the purpose is to reduce the fuel consumed by California’s automotive fleet per mile.” In addition, the complaint alleged that the ZEV mandates conflict with EPCA’s provision that the “maximum feasible” fuel economy standards should be set without regard to ZEVs. The U.S. and DOT asked the court for declaratory relief and to enjoin CARB from enforcing the CO2 standards or ZEV mandates.