Automobile manufacturers are preparing to sue California, perhaps as early as this week, in an attempt to derail a pioneering state law that seeks to force the companies to reduce tailpipe emissions of heat-trapping gases linked to global warming.
Representatives of two major automakers confirmed Monday that a coalition of companies has decided to file a lawsuit that would challenge the state's legal authority to force the reductions from carmakers.
One company official from a domestic automaker who had been briefed on the lawsuit described it as "imminent." However, a representative of a Japanese automaker cautioned that the suit may not be filed until January.
Car companies and an automobile industry trade group repeatedly have argued that the California law -- which requires a nearly 30% cut in greenhouse gas emissions from all passenger vehicles sold in the state by 2016 -- sets a new fuel efficiency standard, which only the federal government has the power to do.
The easiest known way to reduce exhaust of carbon dioxide and other heat-trapping gases is to build cars and trucks that burn less fuel. State officials concede that the new rule probably will lead to more fuel-efficient cars and trucks elsewhere.
Still, the rule-makers maintain that they are regulating only air pollution, not fuel economy, as the auto industry contends.
A spokeswoman for the Alliance of Automobile Manufacturers, a trade group of leading carmakers that includes General Motors, Toyota and Volkswagen, said the group was still deciding whether to sue.
"We are still considering our options and I am not going to predict when and if we might do something," said spokeswoman Gloria Bergquist.
State officials said they hoped to avert a legal dispute.
"We hope that we and the automakers can work out our differences and find some common ground," said California Air Resources Board spokesman Jerry Martin. "We have been doing our best to work with them in hopes of avoiding a lawsuit."
Environmental groups said they hoped that automakers, some of which have tried to cultivate a "greener" image in recent years, would consider polls in California showing that the public supports the greenhouse gas rule. But they acknowledged that they expected a legal showdown.
"They can choose whether to innovate or litigate. We were hoping that leaders in that industry would recognize that the public wants cleaner cars. But it looks as if they are choosing to draw a hard line in California," said David Doniger, a senior attorney at the Natural Resources Defense Council and head of a legal team of environmentalists that plans to help defend the rule.
The first regulation of its kind in the world, California's greenhouse gas rule is being closely watched around the globe. A number of states, including New York, Massachusetts and New Jersey, have indicated that they would like to adopt similar regulations. Canada also has discussed developing a similar standard modeled in part on the California requirement. As a result, auto industry experts said, the state rule could lead to major changes in cars sold throughout North America.
The technology needed to reduce tailpipe emissions of greenhouse gases already exists and is in use in many cars. State officials have cited innovations currently in use that can reduce exhaust, including continuously variable transmissions that shift to find the most efficient gear, engines that shut off cylinders when they are not needed and air-conditioning systems that use alternative coolants.
However, the technology costs more, and requiring it on all California cars and trucks will undoubtedly raise prices. State officials estimate that the average car would cost about $1,000 more by the time the rule is fully implemented in 2016. Car company representatives estimated that the increase would be three times that.
David Cole, chairman of the nonprofit Center for Automotive Research in Ann Arbor, Mich., said car companies were worried that tougher requirements would force them to build vehicles with smaller engines that were less able to tow trailers and boats. Cole and other automotive industry experts said the expected filing of the suit should lead to more frank talks between California and automakers, which have largely avoided discussing their differences with state regulators.
"The car companies see this as an unfair tax on their consumers because it will add to the cost of vehicles and detract from the utility that consumers have come to expect," Cole said.
In addition to arguing that California is attempting to set a new fuel-economy standard, car companies have maintained that the state is overstepping its legal authority by regulating carbon dioxide as a pollutant.
Under the Clean Air Act, California is the only state that can set air pollution standards stronger than those imposed by the federal government. Other states are then free to follow California's standards. Many have done so.
However, the Bush administration ruled last year that it did not consider carbon dioxide a pollutant under the Clean Air Act. A number of states, including California, have challenged the U.S. Environmental Protection Agency decision in court.
State officials also maintain that they can regulate carbon dioxide even if the federal government chooses not to do so.