California sued the U.S. Environmental Protection Agency January 2 for “ignoring the dangerous consequences of global warming.” The move came after the federal agency’s unprecedented denial of a federal Clean Air Act waiver needed to implement the state’s 2002 tailpipe emissions reduction law, AB 1493, for greenhouse gases. “The denial letter was shocking in its incoherence and utter failure to provide legal justification for the administrator’s unprecedented action,” stated California attorney general Jerry Brown. “The EPA has done nothing at the national level to curb greenhouse gases and now it has wrongfully and illegally blocked California’s landmark tailpipe emissions standards, despite the fact that sixteen states have moved to adopt them.” California, along with 15 other states backing the waiver, filed suit in the Ninth Circuit Court of Appeals. The tailpipe law would curb vehicle emissions by 30 percent in 2016. Cars generate 20 percent of all human-produced carbon dioxide emissions in the United States, and about 30 percent of CO2 emissions in California, according to Brown. Stationary sources, like power plants, are responsible for a majority of the greenhouse gases. In California, however, power plants produce about 20 percent of the state’s CO2, but the level is higher in Midwestern and Eastern states that have numerous coal-fired plants. The federal Clean Air Act allows California to implement environmental regulations that are stricter than federal rules when backed by “compelling and extraordinary conditions,” which include unique topography, climate, and serious congestion and pollution, according to Brown. In December of last year, the U.S. District Court in Fresno rejected the auto industry’s challenge to AB 1493, requiring a 30 percent cut in auto tailpipe emissions. In September 2007, a federal court judge in Vermont also rejected a similar effort by the automobile industry to block Eastern states from implementing California’s tailpipe emissions law. Editor’s note: For more on the waiver controversy, please see our sister publication, E=MC2, Energy Meets Climate Challenge: energymeetsclimate.com