Most California voters says global warming is a significant issue but they are closely divided on a November ballot measure that would suspend the state's pioneering law to combat it, according to a new Los Angeles Times/University of Southern California poll.

California's global warming law, the most sweeping in the nation, requires greenhouse gas emissions by power plants, factories and vehicles be slashed to 1990 levels by the end of the decade. Proposition 23 would suspend the 2006 law until the state's unemployment rate drops to 5.5% for an entire year. Unemployment is now more than 12%, and California rarely has a yearlong level below 5.5%.

More than two-thirds of likely voters surveyed said global warming is a "very important" or "somewhat important" issue to them, but only 40% favor the ballot measure and 38% oppose it, reports the Los Angeles Times. One-fifth have yet to take a position. The Times says a ballot initiative with less than 50% support at this point of a campaign typically has trouble, because undecided voters often end up voting no.

Proposition 23 is backed by business groups and out-of-state oil companies, including Koch Industries, Valero Energy Corp. and Tesoro Corp. It's opposed by GOP Gov. Arnold Schwarzenegger, who signed the greenhouse gas bill into law.

The survey of 1,511 registered voters, including 887 considered likely voters, was conducted for The Times and the University of Southern California College of Letters, Arts & Sciences between September 15 and 22, the story says. It was done by two national survey research firms, the Democratic firm of Greenberg Quinlan Rosner and the Republican firm American Viewpoint. For the likely voter segment, the margin of error is plus or minus 3.3 percentage points.