Under the federal Clean Air Act of 1970, California received a waiver to set stricter fuel emissions standards than those imposed by the Environmental Protection Agency. The legal exemption was based on the state’s ongoing issues with smog in metropolitan areas, and it must be renewed periodically, which happened most recently in 2009.
But after years of sparring with the Golden State (over everything from sanctuary laws to homelessness), President Donald Trump threatened to revoke California’s emissions exemption and, as with many of his other threats, the state plans to respond with legal action.
