The Ninth U.S. Circuit Court of Appeals ordered a federal transportation agency on Thursday to rewrite its fuel economy standards for many SUVs, minivans and light trucks, arguing that the new rules are inadequate in part because they fail to properly assess the risk of global warming.
The decision is a huge win for several environmental groups and 11 states, including California, that argued that the National Highway Traffic Safety Administration's new fuel economy standards ignored the effects of carbon dioxide emissions.
The panel also concluded that the agency failed to address why light trucks are allowed to pollute more than passenger cars. And it said the new rules should have included heavier trucks that are used as commuter vehicles.
The decision was the most recent example of growing pressure on the Bush administration to require automobile makers to sell more fuel-efficient vehicles.
Last week, Gov. Arnold Schwarzenegger filed a separate lawsuit against the U.S. Environmental Protection Agency to force the agency to grant a federal waiver for California that would require automakers to revamp their product lineup with more fuel-efficient cars and trucks starting next year. Fourteen other states have petitioned to join that lawsuit.
Under existing rules, certain SUVs, minivans and light trucks are required to achieve an average 22.2 mpg for 2007 models. The new standards, announced in March 2006, would have upped that requirement to 24.1 mpg by 2011.
But the Center for Biological Diversity initiated the petition to the federal appeals court a month later, arguing that a 38 mpg benchmark can be readily achieved by 2015.
Thursday's "court decision is a rebuke to the Bush administration and its refusal to make meaningful steps to reduce global warming pollution from our automobiles," said Pat Gallagher, director of environmental law at the Sierra Club. "The decision tells the National Highway Traffic Safety Administration that it can't monkey the numbers when it sets fuel economy standards by ignoring the cost of carbon emissions."
The Sierra Club was one of more than a dozen environmental groups and states that joined the lawsuit.
On Thursday, White House officials already were eyeing a possible appeal.
"We're in the process of reviewing the decision and will consider all our options," said Charles Miller, a spokesman for the Justice Department's civil division.
Brian Nowicki, the climate policy director for the Center for Biological Diversity, said much of the fuel savings they propose can be achieved by implementing existing technologies.
One example is the new Honda Odyssey minivan, which saves gasoline by shutting down some cylinders in the engine when cruising at high speeds.
"The ruling is not just a token or symbolic win. The fossil fuels burnt and the greenhouse gases emitted by these vehicles are a huge portion that's contributing to global warming, and this ruling will be striking at some of that," Nowicki said.
Dave McCurdy, president and chief executive officer of the Automobile Manufacturers Alliance, an industry trade group, said while more new models contain such fuel-saving technologies, the industry needs adequate lead time to integrate these technologies in all vehicles.
McCurdy defended the 2006 standards as the largest fuel economy increases since the federal government began setting mileage standards more than three decades ago. He added that automakers already have planned their product lines through 2011 with those guidelines in mind.
"Any further changes to the program would only delay the progress that manufacturers have made toward increasing fleet-wide fuel economy," he said in a written statement.
Chronicle staff writer Zachary Coile contributed to this report. E-mail Matthew Yi at email@example.com.
© 2007 The San Francisco Chronicle