Thus far, California’s landmark law to cut greenhouse gases from its factories and businesses—a law that has given Gov. Schwarzenegger an international image of environmental activist—has been mostly talk and little action. Rules covering perhaps 60 percent of the reductions needed to meet the targets are already in place or soon will be, the result of other laws, covering such things as renewable energy standards, energy efficiency, clean-car rules, low-carbon fuel standards and others. One key component, to cut greenhouse gases from car tailpipes, is stalled pending a federal waiver, although that permission is all but certain after President Bush...