California's bold move to slash its greenhouse-gas emissions is the right move at the right time and it has occurred, it must be said, under the right governor.

Despite persistent dissent from a handful of self-serving or self-deluded "skeptics," American public opinion has moved from ambivalence about the actuality of global warming to a solid acceptance of its threats. Now the focus is on what can be done — a daunting question to which California is about to provide practical and probably inspiring answers.

Combustion-driven warming of the world's climate is a problem whose scope is, well, global. But the solutions ultimately will be aggregations of local actions, whether or not directed from a national capital or designed in keeping with an international protocol.

So it is a noble thing for a small town to commit itself to reducing carbon emissions. It is both noble and a substantive step when undertaken by California, whose economy is often ranked as larger than those of all but five of the world's nations.

Cutting the state's carbon dioxide output back to 1990 levels by the year 2020 will be a huge undertaking, but also a potentially profitable one. Researchers at Berkeley have predicted net gains of $74 billion in economic value and 89,000 additional jobs, mostly from new technologies that conserve energy or produce it from clean sources. Some California manufacturers and utilities accuse their legislature and governor of embracing competitive disadvantage, but plenty of businesspeople make the more persuasive case that California is poised once again to lead the nation to a greener, wealthier, healthier future.

This would be true even if the governor in question were, say, Gray Davis. But because it is Arnold Schwarzenegger — known to all as a Republican, pro-business, small-government, Hummer-collecting guy — the naysayers will have a much harder time dissing this initiative as tree-hugging flakiness from the Left Coast.