BURLINGTON, Vermont (AP) — A federal court trial over whether states have the authority to regulate carbon dioxide emissions from automobiles got under way yesterday, with automakers asserting that stricter standards being adopted by states will do little to stem global warming.“The whole truth, as the evidence will show, is that this regulation ... will not have any meaningful impact on global warming,” said Andrew Clubok, an attorney for the automakers.

Green Mountain Chrysler Plymouth Dodge Jeep, Green Mountain Ford Mercury and Joe Tornabene’s GMC of Pownal are plaintiffs in the case, in addition to General Motors Corp., DaimlerChrysler AG and a pair of auto industry trade groups.

The trial, which involves a suit filed by the auto industry, centres on rules adopted by California in 2005 and later by Vermont and other states.

The non-jury trial is the first of a series of court fights expected in the case. It is being heard by US District Court Judge William Sessions III.

The states and several environmental groups say the Clean Air Act is the ultimate word on regulating emissions. The Act allowed California to set more stringent emissions rules than the federal government and let other states piggyback on the California rules.

The trial comes in the wake of an April 2 US Supreme Court ruling that ordered the federal government to take a new look at regulating carbon dioxide emissions, saying the Clean Air Act gives the Environmental Protection Agency the authority to regulate carbon dioxide and other greenhouse gases produced by cars.

Automobile manufacturers and dealers say climate change is not fully understood and that new regulations could carry economically significant consequences.