More than a dozen other states are poised to follow California's lead if it is granted the waiver from federal law, presenting a challenge to automakers who would have to adapt to a patchwork of regulations.
"Our position is that it's time for EPA to either act or get out of the way," said Lee Moore, a spokesman for New Jersey Attorney General Anne Milgram.
California's lawsuit against the Environmental Protection Agency, filed in U.S. District Court in Washington, D.C., was expected after Gov. Arnold Schwarzenegger vowed last spring to take legal action.
At issue is California's nearly two-year-old request for a waiver under the federal Clean Air Act allowing it to implement a 2002 state anti-pollution law regulating greenhouse gases.
Eleven other states have adopted California's standard as a way to combat global warming and five others are considering it.
"The longer the delay in reducing these emissions, the more costly and harmful will be the impact on California," the state attorney general's office said in its 16-page complaint.
Schwarzenegger and other state officials say implementing the law is crucial for California's ability to meet the provisions of a separate global warming law that passed last year, garnering worldwide attention. That law seeks to reduce greenhouse gas emissions 25 percent by 2020.
Arizona, Connecticut, Illinois, Maine, Maryland, Massachusetts, New Jersey, New Mexico, New York, Oregon, Pennsylvania, Rhode Island, Vermont and Washington plan to join California's lawsuit against the federal government, said Gareth Lacy, spokesman for California Attorney General Jerry Brown.
California asked the EPA to grant its waiver in December 2005. EPA administrator Stephen Johnson said last summer that he would make a decision by the end of this year.
Schwarzenegger sought quicker action and vowed to sue. The state's lawsuit was expected to be filed in late October but was delayed after state officials became preoccupied with the Southern California wildfires.
The EPA criticized the state's actions Thursday.
"The administrator has stated numerous times that he plans to make a decision by the end of the year," EPA spokeswoman Jennifer Wood said. "It's unfortunate that California is more interested in getting a good headline than allowing us to make a decision."
Yet state officials say they need the matter resolved soon because the auto-emissions law applies to vehicles in the 2009 model year, which can be marketed by companies as early as this coming January.
Cars, pickups and sport utility vehicles sold in California would be required to produce fewer greenhouse gases, with the goal of reducing auto emissions 25 percent by 2030.
Further delay by the EPA would interfere with the state's ability to enforce the law on time, according to the complaint.
"Congress generally intended that the U.S. EPA make determinations of this type in a matter of weeks or months, not years," the complaint says.
While the federal government sets national air pollution rules, California has unique status under the Clean Air Act to enact its own regulations if it gets approval to do so by the EPA.
Other states can follow federal rules or California's standards if they are tougher. The EPA has granted about 50 such waivers over the past 40 years for the use of catalytic converters, leaded gasoline regulations and other measures.
The complaint filed Thursday claims the EPA failed to act in a reasonable length of time on California's latest waiver request.
In addition to the states that plan to join California's lawsuit, the governors of Colorado, Florida and Utah have said their states plan to adopt the standard.
The EPA initially refused to act on California's application, saying the agency did not have the authority to regulate greenhouse gases as a pollutant. That changed when the U.S. Supreme Court ruled in April that the EPA did indeed have that right.
As a result, the EPA is now developing greenhouse gas regulations that are scheduled to be released by the end of the year. Environmental groups say those regulations are unlikely to be stronger than California standards.
Automakers continue to challenge the California standards in court.
They are appealing a ruling last month by a federal judge in Vermont who upheld the California rules in that state. They also are trying to persuade a federal judge in Fresno to toss out the emission standards mandated under California's 2002 law.
Associations for both domestic and foreign car companies say California's standards would raise the cost of vehicles and could force manufacturers to pull some sport utility vehicles and pickup truck models from showrooms.