Arizona is formally withdrawing from the Western Climate Initiative, a regional collaboration to establish a cap-and-trade program to reduce emissions of greenhouse gases.
Arizona became a WCI member under Democratic Gov. Janet Napolitano. She resigned in 2009 and was replaced by Republican Jan Brewer.
Brewer kept Arizona in the WCI, but ordered that the state not implement the cap-and-trade program.
The Arizona Department of Environmental Quality now says the state is going further by withdrawing formally from WCI.
Environmental Quality Director Henry Darwin says Arizona is joining a new multistate collaborative effort to explore customized use of other approaches such as use of biomass fuels.
Meanwhile, California is still moving to implement a cap-and-trade program with four Canadian provinces: British Columbia, Manitoba, Ontario and Quebec.