In this Thursday, April 29, 2010 file photo, a pair of coal trains idle on the tracks near Dry Fork Station, a coal-fired power plant being built by the Basin Electric Power Cooperative near Gillette, Wyo. The world's emissions of heat-trapping carbon dioxide took the biggest jump on record, the U.S. Department of Energy calculated, a sign of how feeble the world's efforts are at slowing man-made global warming. The new figures for 2010 mean that levels of greenhouse gases are higher than the worst case scenario outlined by climate change experts just four years ago. China, the United States and India are the world's top producers of greenhouse gases. Tom Boden, director of the Energy Department's Carbon Dioxide Information Analysis Center at Oak Ridge National Lab, said that in 2010 people were traveling, and manufacturing was back up worldwide, spurring the use of fossil fuels, the chief contributor of man-made climate change. (AP Photo/Matthew Brown)
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.