Automakers have asked a federal judge to throw out Vermont’s adoption of California carbon dioxide limits for vehicles. Vermont, New York state and five environmental groups are defending the rules as a legal, reasonable, affordable and necessary step to combat global warming.

The Vermont case is Green Mountain Chrysler Plymouth Dodge Jeep et al. v. George Crombie, Vermont Secretary of Natural Resources,et. al. Case No. 2:05 –cv-302. Similar cases are pending in California and Rhode Island.

In its recent decision in Massachusetts v. EPA, the Supreme Court held that carbon dioxide was a pollutant that falls under the regulatory purview of the Clean Air Act, and that the EPA has the authority to regulate it. The EPA had argued that the emissions were not regulable under the Clean Air Act, and that it had no authority to do so. (Earlier post.)