In a ruling last Wednesday-potentially as significant as the CAFE standards of the energy bill-United States District Judge Anthony W. Ishii rejected a lawsuit challenging California’s 2002 Clean Car Act (AB1493), which calls for vehicles to produce less greenhouse gas emissions.

California’s Air Resources Board (CARB) adopted regulations in response to the Act that will phase in and ramp up over eight years to cut global warming emissions from new vehicles by nearly 30 percent by model year 2016. To date, California’s standards have been adopted (or plans to adopt have been announced) by 17 states representing almost half of the U.S. population.

In a detailed analysis of the plaintiffs’ claimed conflict between the Clean Air Act and Energy Policy and Conservation Act (EPCA), Judge Ishii wrote:

Given the level of impairment of human health and welfare that current climate science indicates may occur if human-generated greenhouse gas emissions continue unabated, it would be the very definition of folly if EPA were precluded from action simply because the level of decrease in greenhouse gas output is incompatible with existing mileage standards under EPCA.

One more barrier exists before California can begin put its plans for cleaner cars into effect: a waiver from the EPA. Judge Ishii’s analysis hinges upon this waiver since it makes the conflict between two Federal agencies, instead of the Federal government and a state. Over the past 30 years the U.S. EPA has granted California more than 40 such waivers, denying none. California requested the waiver in 2005 and in the past the EPA has acted quickly. About such waiver requests, Judge Ishii wrote in his opinion: