California can implement greenhouse gas emissions standards for new cars and trucks sold in the state, EPA decided last week. The move overturns the Bush Administration's 2008 denial of the state's request to impose the emissions limits, which automakers strongly opposed. EPA reexamined the 2008 decision at the direction of President Barack Obama. In reversing the 2008 determination, EPA allows California to require that new vehicles sold within the state meet lower emissions requirements for CO2 and methane from tailpipes, as well as hydroflurocarbons, used as refrigerants in air-conditioning systems. The agency's move clears the way for 13 other states and the District of Columbia to adopt California's greenhouse gas emissions standards for vehicles. But the determination will have only a short-term effect. EPA officials say the California requirements will be eclipsed in 2012, when planned new national standards that combine higher fuel economy and lower greenhouse gas emissions kick in for new cars and trucks.