The California government today filed a lawsuit against the U.S. Environmental Protection Agency for "wrongfully and illegally" blocking the state's tailpipe greenhouse gas emissions standards. Fifteen other states joined the California lawsuit, and in addition, five nonprofit groups today filed suit challenging the EPA's decision.

The waiver, allowing California to enact and enforce standards to reduce greenhouse gas emissions from automobiles, was requested after the California Air Resources Board developed regulations based on a 2002 state law that requires new standards for motor vehicle greenhouse gas emissions beginning in model year 2009.

The regulations will phase in and ramp up over eight years to cut emissions from new vehicles by nearly 30 percent by model year 2016. The state program would be the first legally binding program in the country to strictly limit greenhouse gases.

Under the Clean Air Act, California is the only state that has the right to enact standards stricter than those of the federal government, but any new standards require approval in the form of a waiver from the U.S. EPA of less stringent federal standards.

Once California's request for a waiver is approved, other states that have adopted California's new tailpipe standards receive automatic approval.

EPA Administrator Stephen Johnson denied California's request for a waiver on December 19, 2007 in a letter to Governor Arnold Schwarzenegger.

California's petition for judicial review of the EPA denial and the other legal actions were filed today in the Ninth Circuit Court of Appeals.