PROVIDENCE — Local environmental advocates are hailing two developments in the legal battle over whether states, including Rhode Island, can regulate greenhouse gas emissions from vehicles.

Governor Carcieri on Wednesday joined a dozen other governors in calling for automakers to drop lawsuits challenging the authority of states to set limits on carbon dioxide emissions from autos.

And on the same day, a federal judge in Vermont ruled that states can regulate those emissions, rejecting automakers’ claims that federal law preempts state rules and that technology can’t be developed to meet them.

“The court and the governors are telling the automobile industry the same thing: It’s time to fire the lawyers and hire the engineers,” said Cynthia Giles, director of the Rhode Island Advocacy Center for the Conservation Law Foundation, which is involved in one of the local cases. “Stop fighting and get to work producing cleaner cars.”

Matt Auten, an advocate for Environment Rhode Island, said, “The decision in Vermont and the governors’ letter are saying these are common sense standards to tackle global warming and save consumers money at the pump.”

The Alliance of Automobile Manufacturers issued a statement responding to both the Vermont decision and the letter from the 13 governors.

“Federal law is designed to ensure a consistent fuel-economy program across the country,” alliance president and Chief Executive Officer Dave McCurdy said. “It makes sense that only the federal government can regulate fuel economy. Automakers support improving fuel-economy standards nationally, rather than piecemeal, and will continue to work with the Congress, [the National Highway Traffic Safety Administration] and [the Environmental Protection Agency] to reduce our oil dependence while increasing fuel economy.”

McCarthy said the alliance plans to study the Vermont decision and is considering an appeal.

Carcieri, a Republican, joined a bipartisan group of governors from California, Connecticut, Massachusetts, Maine, New York and seven other states in signing a letter sent to General Motors, Chrysler, Honda, Ford, Toyota and Nissan executives.

“The impact of global warming presents a grave threat to public health, natural resources and our economy,” the governors said. “The public is demanding that states, in the absence of federal action, take real and meaningful steps to reduce emissions of greenhouse gases. Ensuring that our automobiles have a lower carbon footprint is an essential piece of our greenhouse gas reduction strategy.”

The governors said that in the case of Massachusetts v. the Environmental Protection Agency, the U.S. Supreme Court found that the EPA has the authority to regulate greenhouse gases and the EPA must exercise that authority if it finds those gases may reasonably be anticipated to endanger health.

“In light of this decision, we do not believe it is productive for your industry to continue to fight state implementation of clean tailpipe standards,” the governors wrote. “As governors committed to addressing the issue of climate change, we ask that you withdraw your legal challenges to clean vehicle standards and begin working with us to meet our joint obligations to begin reversing the threat of global warming. We would prefer to follow a path that encourages innovation not litigation.”

Meanwhile, a federal judge in Burlington, Vt., ruled that states can regulate greenhouse-gas emissions from vehicles.

During a 16-day trial that ended in May, auto industry executives had testified that regulations adopted by California and 11 other states would not stop global warming but would impose devastating new costs on the industry. Slated to start phasing in as of 2009, the limits would require a 30-percent reduction in carbon dioxide emissions from cars and trucks by 2016, a standard that carmakers have maintained would require average fuel-economy standards for cars and the lightest category of trucks of 43.7 miles per gallon.

But U.S. District Judge William K. Sessions III ruled that Vermont’s “Clean Car” regulations were properly adopted and did not conflict with other federal laws designed to regulate the fuel efficiency of motor vehicles. The judge said there was no question that greenhouse-gas regulations “present great challenges” to automakers, but he said, “History suggests that the ingenuity of the industry, once put in gear, responds admirably to most technological challenges.”

Attorney General Patrick C. Lynch, a Democrat, said, “The ruling speaks to many of the same issues raised in Rhode Island’s pending Clean Car case and embraces a sensible approach to dealing with fuel efficiency and global warming.”

Automakers have filed two lawsuits in U.S. District Court in Providence.

One suit, filed by the Association of International Automobile Manufacturers, argues, among other things, that the Clean Air Act gives the EPA exclusive authority to regulate car emissions. The only exception allows California to seek an EPA waiver and for other states to adopt standards identical to California. But, the suits say, California has not obtained a waiver for its regulations, so Rhode Island can’t adopt and enforce California’s regulations.

Another suit, filed by a variety of auto dealers and the Alliance of Automobile Manufacturers, argues, among other things, that, “It is not the prerogative of any individual state in the union to attempt to establish policy for global-climate matters through the regulation of motor vehicles. The United States is committed to addressing global climate change through multilateral agreements, and to date has chosen to refrain from motor-vehicle greenhouse-gas controls at the international level.”

In response, lawyers from the state argue that the lawsuits are premature, saying Rhode Island can’t enforce the new regulations unless and until the EPA grants a waiver to California. “Until EPA rules on California’s waiver request — a ruling that can take a number of years — plaintiffs’ case is not ripe for view,” the state lawyers wrote. “If EPA denies the State of California’s waiver request, then there are no preemption issues for this court to adjudicate.”

On Friday, Carcieri spokesman Jeff Neal said the governor “believes that states like Rhode Island must have the freedom to fight pollution.”

“Under the governor’s direction, the state adopted the California auto-emission standards, which are among the toughest in the nation,” Neal said. “Unfortunately, the auto industry has fought our efforts to keep Rhode Island’s air clean, going so far as to take our state and others to court.”

With Wednesday’s decision from the judge in Vermont, Neal said, “Governor Carcieri is hopeful that the auto industry will back off, recognize Rhode Island’s right to regulate pollution inside our borders, and work with us to improve the environment for our citizens.”

Attention now turns to whether the EPA will grant California a waiver. The Alliance of Automobile Manufacturers said, “The Alliance remains committed to working with policymakers to make certain that the EPA’s judgment is based on credible, sound scientific data as to what policies truly impact California, its citizens and global climate concerns.”

Lynch said he testified before the EPA at a May hearing to determine the need for California’s auto emission standards. And on Friday he said, “EPA’s decision to grant or deny California’s waiver request is critical to the interests of the State of Rhode Island and critical to our ability to minimize the impacts associated with climate change.”

— With Associated Press reports

efitzpat@projo.com