California has been fighting the federal EPA over the issue for years. The agency's approval announced Tuesday is needed before a 2004 state pollution law to combat global warming can go into effect. It would require the fuel efficiency of motor vehicles to increase by 40 percent by 2016 to an average of 35.5 miles per gallon.
The decision had been expected. President Barack Obama in May announced a national requirement similar to the one in California. The federal waiver for California to go ahead with its rule sets the stage for the national program.