"WASHINGTON -- California officials and clean air advocates are increasingly concerned the Trump administration may attempt to unravel a key program to drive down greenhouse gas emissions from automobile fleets while also jeopardizing the ability of California and other states to set pollution standards stronger than federal rules.
Backed by automakers, Trump officials are in talks with their California counterparts to weaken tough vehicle tailpipe standards approved by the Obama administration. The standards are aimed at reducing greenhouse gases, but could also help reduce emissions that cause smog and particulate pollution, and 13 other states have adopted them, including Washington, Pennsylvania and New York.
California has long enjoyed the authority to set pollution standards stronger than the federal government’s, a legacy of the state’s early battles against urban smog, which predated the 1970 Clean Air Act. But in testimony to a Senate committee last week, U.S. Environmental Protection Agency Administrator Scott Pruitt left open the possibilty he might seek to revoke California’s authority."