Attorney General Terry Goddard and Department of Environmental Quality (ADEQ) Director Steve Owens today announced that Arizona is joining a lawsuit brought by California against the U.S. Environmental Protection Agency (EPA) to uphold the right of states to regulate greenhouse gas pollution from automobiles.

“This latest action by EPA to prohibit Arizona and other states from regulating harmful air pollution emitted from cars is baseless,” Goddard said. “Reducing greenhouse gases is vital to address climate change.

In a landmark ruling last year, the U.S. Supreme Court affirmed that states have legitimate interests in protecting the health and well-being of their citizens from the threats caused by those emissions.”

Arizona joined 15 states in today’s lawsuit, which seeks to reverse the EPA decision.  

The lawsuit was filed in the U.S. Court of Appeals for the Ninth Circuit.

ADEQ is in the process of adopting the California standards.  

According to Owens, ADEQ expects to formally propose a draft rule adopting the standards within the next few weeks and to have the final rule approved by early summer at the latest.

“Vehicle emissions are the largest single source of greenhouse gases in Arizona,” Owens said. “If we are going to reduce greenhouse gas emissions in this state, we have to reduce emissions from automobiles.”

Between 1990 and 2005, Arizona’s emissions grew by 56 percent, the fastest rate of growth in the country. If unchecked, emissions in Arizona are projected to increase 148 percent over 1990 levels by 2020.

Nearly 40 percent of the state’s greenhouse gas emissions come from vehicles.  

The federal Clean Air Act gives California the unique authority to set its own more stringent regulations for new cars.

The law also allows other states, like Arizona, to adopt California’s regulations rather than those set by the federal government.  However, the Clean Air Act requires EPA to provide a waiver before the state regulations can be implemented.

California adopted its “Regulation to Control Greenhouse Gas Emissions from Motor Vehicles” in August 2005.  This regulation requires reductions in fleet-average, greenhouse-gas emissions for most new vehicles sold in California, beginning with the 2009 model year.

In December 2005, California requested a waiver from EPA to implement these new regulations. On Dec. 19, EPA denied the request, preventing California and all other states from implementing greenhouse gas emissions standards for cars.

Since California adopted its greenhouse-gas regulations for cars, 14 states have either adopted the California regulation or are in the process of adopting them: Arizona, Connecticut, Florida, Maine, Maryland, Massachusetts, New Jersey, New Mexico, New York, Oregon, Pennsylvania, Rhode Island, Vermont and Washington.  

Gov. Janet Napolitano issued an order for Arizona to adopt the California regulations as part of the state’s effort to address climate change.