U.S. Clean-Car Rules Are Essentially Eliminated by EPA Rollback

The E.P.A. rescinded the 2009 "endangerment finding," removing the federal legal basis for greenhouse-gas tailpipe rules; California and environmental groups have said they will challenge the decision.

The E.P.A. has rescinded the 2009 "endangerment finding," a scientific determination that had provided the agency with the legal basis to regulate greenhouse gases from vehicles. That action follows a year of regulatory rollbacks and means the federal government no longer has enforceable greenhouse-gas tailpipe standards in place. Transportation remains the single largest source of U.S. greenhouse-gas emissions, and observers say the change could affect how automakers design future lineups. Key facts: - The E.P.A.'s elimination of the endangerment finding removes the agency's legal authority to write greenhouse-gas emission rules for cars and trucks. - As a practical result, the United States currently lacks federal enforceable clean-car efficiency or greenhouse-gas tailpipe standards. - The Department of Transportation still has a role over fuel economy, but recent proposals and congressional actions have reduced penalties and proposed weaker targets. - California has vowed to sue and environmental groups have announced plans for legal challenges to the E.P.A. decision. Summary: The decision narrows the federal regulatory tools available to limit vehicle greenhouse-gas emissions and could influence automakers' product plans and international competitiveness. Environmental groups and at least one state have announced legal challenges, and the longer-term regulatory authority is uncertain while court proceedings and policy debates proceed.