The Environmental Protection Agency (EPA) has taken final action to revoke California’s authority to set its own vehicle emissions standards that are more climate-protective than federal requirements. The EPA’s mandate to set emission standards for new motor vehicles under the Clean Air Act generally preempts states’ ability to establish such standards. However, California can seek a waiver to set its own regulations that are at least as protective as applicable federal rules, which other states may follow.
In 2013 EPA granted California a preemption waiver for its Advanced Clean Car (ACC) regulations. The ACC program is comprised of California’s low emission vehicle program, greenhouse gas standards, and zero-emission vehicle (ZEV) program. The ZEV program requires a certain percentage of vehicles in the state to produce no carbon dioxide tailpipe emissions. Today’s action withdraws the preemption waiver for California’s greenhouse gas standards and the ZEV mandate. According to the California Air Resources Board, thirteen other states have adopted California’s greenhouse gas rules and ten have implemented the ZEV program.
This rule finalizes portions of the Safer Affordable Fuel-Efficient Vehicles Rule proposed by EPA and the National Highway Traffic Safety Administration (NHTSA) in August 2018. EPA and NHTSA are working to finalize the remainder of the proposed rule, which would weaken federal greenhouse gas and fuel economy standards for new motor vehicles.