The automobile industry is taking Vermont to court over new clean air regulations.

Vermont has followed California's plan to restrict carbon dioxide pollution from new cars and trucks.

But the car companies claim the new rules are illegal under federal law.

VPR's John Dillon has the story.

(Dillon) Vermont's new regulations require a gradual reduction of the main pollutant that's blamed for global warming.

Beginning with the 2009 model year, automakers would have to cut carbon dioxide emissions by 2%. The rules are designed to lead a 30% reduction by 2016.

But the car industry says that Vermont and the six other states that adopted the California clean air standards are violating federal law.

Gloria Bergquist represents the Association of Automobile Manufacturers. She's says that by placing limits on C02 emissions, the states are actually regulating fuel economy. And she says that's not allowed under federal law.

(Bergquist) "No one state, no group of states can set their own fuel economy standards. Only the government can set fuel economy standards."

(Dillon) Four Vermont car dealerships have joined the lawsuit as well. Bergquist says consumers would have to pay more for the cleaner cars.

(Bergquist) "It is expected to raise the cost of new vehicles by at least an average of $3,000 per vehicle."

(Dillon) But Environmental Commissioner Jeff Wennberg says the lawsuit is part of a long history of car companies resisting regulation.

He says the manufacturers fought requirements for airbags and other safety features. Now, Wennberg says, the companies have embraced the safety technology and use it to market their vehicles.

(Wennberg) "This is bound to follow much the same pattern. It's just that you've got to start by making the cars available, and if they're not going to do it unilaterally, we can do it regulatorily over time."

(Dillon) Wennberg says the regulations will lead to a substantial reduction in the pollution that's blamed for global warming.

(Wennberg) "By 2016, across the fleet, we expect in Vermont based on the cars Vermonters buy, a 22-23% reduction in greenhouse gas emissions from passenger vehicles and light trucks. Well that ain't chicken feed. That's a real reduction in what is the single biggest source of greenhouse gas emission in the state. So it's important for Vermont to do this."

(Dillon) A leading environmental group plans to help the state defend the new regulations in court. Chris Kilian is the Vermont director of the Conservation Law Foundation.

(Kilian) "Vermont's being targeted because the auto industry is fighting tooth and nail in every state where this program is being implemented to derail it."

(Dillon) Kilian challenges the industry's legal argument. He says federal law specifically allows other states to follow California's lead in developing emissions standards.

For Vermont Public Radio, I'm John Dillon.