A neighboring state has dropped out of a regional cap-and trade scheme championed by California.
A few years back, California helped establish the Western Climate Initiative with six other U.S. states and four Canadian provinces. The idea when the federal government wasn't making much climate policy was to create a regional pact that would reduce the greenhouse gases that contribute to global warming.
A key part of the initiative is a carbon market – in which polluters in member states and provinces could trade greenhouse gases with an aim of eliminating them. Opponents of these markets argue they'll carry a heavy cost.
That's creating political pressure on states committed to a regional cap and trade scheme. In Arizona, the governor has signed an order to leave the carbon market because of concerns it would cripple the state's economy.
That leaves California the only state saying it's ready to start trading carbon in just under two years. A spokeswoman for California's environmental protection agency says Arizona's still an important partner in the initiative's other programs.