California Attorney General Xavier Becerra today, with Governor Gavin Newsom and the California Air Resources Board, led a coalition of 24 state attorneys general and the cities of Los Angeles and New York in filing a lawsuit against the National Highway Traffic Safety Administration (NHTSA).

The lawsuit challenges the Trump Administration’s newly announced One National Program Rule (earlier post) designed to preempt California’s greenhouse gas emissions and Zero-Emission Vehicle (ZEV) standards, also known as California’s Advanced Clean Car Standards, which were authorized by a waiver granted by the US Environmental Protection Agency (EPA) in 2013 (following a denial in 2007). (Earlier post.).

These standards are followed, in whole or part, by 13 other states and the District of Columbia.

In the lawsuit, the coalition broadly asserts that this Preemption Rule is unlawful and should be vacated.

The state’s lawsuit argues that NHTSA is attempting to declare the California greenhouse gas and ZEV standards preempted under the Energy Policy and Conservation Act (EPCA), and is overstepping the authority granted to it by Congress, ignoring what it calls “Congress’ careful and repeated preservation of California’s authority.”

In its argument, the states conflate the multiple-decade history of state regulation of criteria pollutants with the more recent addition of greenhouse gas regulations and the ZEV mandate. In its new ruling, due to go into effect in 60 days, the Trump administration differentiates between GHG (and by extension fuel economy) and ZEV mandates, which it claimed within the purview of federal regulations, and California’s long-standing efforts to combat tailpipe criteria pollutants such as unburned hydrocarbons, PM, NO_x etc. The later, the Trump administration said, was still within California’s purview.