In a joint press conference on September 15, the U.S. Environmental Protection Agency (“EPA”) and U.S. Department of Transportation (“DOT”) released details of a new national suite of automobile standards that would mandate increased corporate average fuel economy (“CAFE”) standards and carbon dioxide (CO2) emissions limits. The new rulemaking will impose a CO2 limit on passenger cars, light-duty trucks, and medium-duty passenger vehicles of an average of 250 grams per mile per vehicle by 2016 and would go into effect with model year 2012.  The limit would force CAFE standards to a fleetwide average of 35.5 miles per gallon by 2016, four years ahead of the schedule Congress imposed in its 2007 energy law. 

The joint rulemaking follows an announcement by the Obama administration in May to combine the legal authority granted EPA in the 2007 U.S. Supreme Court decision Massachusetts v. EPA with DOT’s authority under the CAFE program to enact national automobile greenhouse gas standards.  The President proposed to merge a new CAFE rulemaking with California’s efforts to impose its own tailpipe emissions standards, standards that now have been adopted by thirteen other states and the District of Columbia.  If finalized, the new national standards are likely to moot California’s standards by their implementation in 2012, creating what the auto industry hopes will be a more uniform national regulatory environment.

 The EPA portion of the joint rule would represent EPA’s first regulation of greenhouse gases and is expected to be followed by a series of other greenhouse gas regulations for other sectors of the economy, with powerplants expected to be next up.  Additionally, when the automobile standards become final, greenhouse gases, including carbon dioxide, will become regulated air pollutants under the federal Clean Air Act, which will automatically trigger permitting requirements for large stationary sources emitting those substances.

 EPA cannot finalize the vehicle emissions rules until it has finalized its proposed “endangerment finding,” released in April, that greenhouse gases endanger health and welfare. The endangerment decision is expected by next spring but could come much sooner.  It is expected that DOT and EPA will finalize the rules by March 31, 2010 to meet a statutory requirement under the CAFE program that standards be completed 18 months before the next model year begins on October 1.