PHOENIX – In the 10 years from 1990 to 2005, greenhouse gas emissions in Arizona grew by 56 percent, the fastest rate of growth of any state in the country. In an attempt to limit this growth, the Arizona Department of Environmental Quality has begun its formal rulemaking process to adopt a clean car program with new standards to reduce greenhouse gas emissions from passenger vehicles, according to ADEQ Director Steve Owens. The new rules are being developed pursuant to an Executive Order on climate change issued last year by Governor Janet Napolitano. The Arizona Climate Change Advisory Group unanimously recommended that Arizona adopt the new greenhouse gas reduction standards. If unchecked, Arizona’s greenhouse gas emissions are projected to grow by 140 percent between 1990-2020 and by 200 percent between 1990-2040. Roughly 40 percent of Arizona’s greenhouse gas emissions come from vehicles. The rules will apply to vehicles beginning with the 2011 model- year. Arizona’s rules will be based on the Clean Car program adopted by the state of California. States are authorized under the federal Clean Air Act to adopt California’s vehicle emissions standards once the U.S. Environmental Protection Agency has issued a waiver that allows California to escape the bonds of the more lax federal rules. The EPA has been withholding that waiver, and earlier this month the state of California sued the federal agency to force issuance of the waiver. In addition to California, 11 other states have adopted the California greenhouse gas vehicle standards. They are Connecticut, Maine, Maryland, Massachusetts, New York, New Jersey, Oregon, Pennsylvania, Rhode Island, Vermont, and Washington. Along with Arizona, at least four other states — Colorado, Florida, New Mexico, and Utah — also have announced plans to adopt the California greenhouse gas vehicle standards.