That's the message of the state's new proposed auto regulations, which would cut greenhouse gases emitted by passenger cars and trucks nearly 30 percent over the next decade. It's a message with bipartisan punch. The climate change plan, made available for public comment on June 14 by the Air Resources Board of the California Environmental Protection Agency, is the result of legislation signed into law by former Democratic Gov. Gray Davis in 2002. But the current Republican governor, Hummer-driving Arnold Schwarzenegger, has also pledged to uphold the new rules and defend them in any potential court battles.

The plan has outraged automakers and is setting up what could be another juicy showdown over the environment between the federal government and California. By going after carbon-dioxide emissions, which are considered by most climate scientists to be a major contributor to global warming, California is opening up a new front in the struggle over who controls fuel efficiency standards. Because unlike what are traditionally considered air pollutants, carbon-dioxide emissions, a byproduct of burning fossil fuel, cannot be filtered out at the tailpipe. To achieve the mandated reductions, the fleet of cars and trucks on the road in California must become fundamentally more fuel-efficient, burning less fuel per mile traveled.

Automakers are screaming because they say that by attempting to limit motor vehicle contributions to global warming, California is effectively regulating fuel economy. And that's supposed to be something only the federal government can do. (Although at the moment, the EPA seems more interested in making fun of drivers who want more fuel efficient cars than in actually increasing fuel economy.)

The fact that California can regulate air pollution from automobiles at all is a twist of regulatory history that dates back to California's horrendous smog problems in the 1960s. California began regulating the tailpipe well before the federal government got around to it in the Clean Air Act of 1970. When federal standards were finally set, California's laws were grandfathered in, and the state was allowed to continue to set its own standards. There's just one catch: As a result of the Energy Policy and Conservation Act of 1975, the feds retained the right to set the CAFE standards -- or Corporate Average Fuel Economy -- the fuel-efficiency minimum levels which cars and trucks must meet.

The rest of the story can be found at: http://www.salon.com/tech/feature/2004/06/28/california_global_warming/index.html