[JURIST] The Environmental Protection Agency (EPA) [official website] on Thursday held a hearing [press release] to reconsider California's request to regulate automobile greenhouse gases [materials]. Chairwoman of the California Air Resources Board [official website] Mary Nichols was joined by environmental groups and other state officials [AP report] at the hearing to encourage the EPA to reverse its prior decision [text] denying California's request. Thirteen states and the District of Columbia seek to adopt standards similar to California's. The Clean Air Act provisions on state standards [text] prohibit states from "adopt[ing] or attempt[ing] to enforce any standard relating to the control of emissions from new motor vehicles or new motor vehicle engines." However, a state can obtain a waiver for exemption from this policy following a public hearing "if the State determines that the State standards will be, in the aggregate, at least as protective of public health and welfare as applicable Federal standards." No such waiver will be issued if the EPA finds that "the determination of the State is arbitrary and capricious," "such State does not need such State standards to meet compelling and extraordinary conditions," or that "such State standards and accompanying enforcement procedures are not consistent with" Section 202(a) [text] of the Clean Air Act [materials].

California's request was initially denied in March 2008 on the grounds that California's regulations were aimed at addressing global climate change and that the Clean Air Act "intended to allow California to promulgate state standards" to "address pollution problems that are local or regional." In January, President Barack Obama ordered [memorandum; JURIST report] the EPA to reassess its 2008 holding. In May 2008, a report by the US House Committee on Oversight and Government Reform found that the Bush White House had influenced the March 2008 decision and that the administration later refused to turn over requested documents [JURIST reports] concerning the decision to the committee, citing executive privilege. The 2007 Supreme Court decision of Massachusetts v. Environmental Protection Agency [decision, PDF] held that the EPA has the authority to regulate automobile greenhouse gas emissions under the Clean Air Act.