Proposition 23 is billed as a titanic battle between Big Oil and Big Green, slugging it out over California’s budding attempts to fight climate change.

It’s certainly going to be an expensive ballot fight, with out-of-state oil companies and other business interests funneling more than $3 million into the campaign to suspend Assembly Bill 32, California’s California Global Warming Solutions Act. Environmental groups have put up $2 million to save the ambitious climate-change law.

But even if Prop. 23 passes in November, most of California’s rules and regulations on greenhouse gases would remain on the books. Instead of saving the economy from overzealous environmental regulation, the measure is more likely to spawn lawsuits and confusion – and send a message to clean-tech investors that California can’t make up its mind.

According to Deloitte Consulting, $2 of every $3 invested in clean energy were spent here in California in the last year. Prop. 23 would likely kill much of that investment, says V. John White, an environmental consultant and backer of AB 32.

“The problem is that this is going to be a monkey wrench right at the time when we’re trying to launch this new economy,” he says.

In some ways, AB 32 may become a victim of its own hype. Democratic leaders and Gov. Arnold Schwarzenegger certainly enjoyed a national spotlight when AB 32 became law in 2006. But to its critics, AB 32 represented the many-headed monster of government regulation. “They are going to regulate every part of your life,” says Assemblyman Dan Logue (D – Sacramento), one of the authors of Prop. 23.

The California Air Resources Board is looking for ways to reduce greenhouse-gas pollution in every sector of the economy. But as laws go, AB 32 is actually pretty sparse.

Mostly, it sets a goal of reducing greenhouse-gas emissions to 1990 levels by the year 2020, and then provides a framework for lots of other laws and regulations, most of which became law completely independent of AB 32.

In order to meet the goals of AB 32, the state will have to cut about 175 million metric tons of climate-change gases – primarily carbon dioxide, but also heavier, more potent pollutants, like methane and hydrofluorocarbons.

Implementation of AB 32 will involve dozens of programs, but just a handful will do the heavy lifting.

The most controversial is a proposed “cap and trade” scheme, which would limit emissions from the state’s biggest polluters, like electricity power plants and oil refineries.

The state’s climate-change strategy also includes California’s clean-car rules, called the “Pavley regs,” and California’s low-carbon-fuel standard, requiring cleaner auto fuels to be sold in the state.

The two other major programs include California’s renewable electricity standards, requiring electric utilities to boost their green power supplies, and a suite of energy-efficiency programs being promoted and administered by the California Public Utilities Commission.

If it became law, Prop. 23 would suspend one, or maybe two, of those big programs until the state unemployment rate (now above 12 percent) drops to 5.5 percent or less, and stays there for a year – a level so low, enviros argue, that AB 32 could never limbo under it.

Any cap-and-trade plan would certainly be one of the programs frozen by Prop. 23. In fact, there’s a good chance cap-and-trade would get suspended even if Prop. 23 doesn’t pass; it’s that politically controversial and confusing to voters.

But most of other the big programs that achieve the emissions-reduction targets in AB 32 could remain intact.

For example, California’s clean-car rules, requiring automakers to reduce 30 percent of carbon-dioxide emissions from new cars and trucks by 2016, actually predate AB 32. And the Pavley regs have since been adopted by the U.S. Environmental Protection Agency as the national standard.

Likewise, the state’s renewable portfolio standard, requiring electric utilities to source 20 percent of their power from clean sources by this year, would survive because it was enacted by earlier legislation. That’s little consolation, since none of the state’s big private electricity providers will meet the 2010 goal. But more aggressive renewable targets would also probably be exempt from Prop. 23.

“If it doesn’t say ‘AB 32,’ there’s probably a strong argument that they could still do it,” says Prop. 23 spokeswoman Anita Mangels.

By that logic, a new law sponsored by state Sen. Joe Simitian (D – Santa Clara), which would boost the renewable portfolio standard to 33 percent by 2020, should also be unaffected by Prop. 23.

The state Air Resources Board includes about 70 different programs in its greenhouse-gas-reduction toolbox. White says the initiative is so broadly written that it’s hard to tell which regulations and programs would remain, which would be nixed and which would wind up in the courts.

“The way it’s written, it can cause a lot of mischief,” he says. “We’d probably be able to muddle through. It’s the uncertainty and the litigation that worries me.”

Backers of the initiative agree that much of Prop. 23’s impact will be sorted out by judges. Logue says even he isn’t sure which pieces would be scrapped by the new law and which would be left unscathed: “It’s a good question. I think there’s going to be a lot of legislation that’s going to be tested in the courts.”

One might wonder how Prop. 23’s backers hope to save the economy from environmental regulation if they’re not even sure what the measure would do.

“AB 32 does have some severely detrimental programs, like cap-and-trade and like the low-carbon-fuel standard,” Mangels says.

But it’s arguable whether the low-carbon-fuel standard is wholly a creature of AB 32, since the governor issued a very similar executive order in 2007. It’s also true that the low-carbon rules might not survive a lawsuit, currently underway, by trucking companies and oil refiners. White says the fuel standard in particular explains the existence of Prop. 23.

In the spring of this year, Logue’s ballot measure appeared to be floundering and lacked the money needed to go forward. But a cash infusion from some Texas oil companies funded the signature-gathering campaign needed to get it on the ballot (see sidebar, this page).

“Somebody at the highest levels of Valero and Tesoro decided to take this right-wing, crackpot, Tea-Party idea and make it something real,” White says.

He has reason to be nervous. A late September Los Angeles Times/University of Southern California poll showed the state’s voters are keen to the perils of global warming – two-thirds said the issue was at least “somewhat important.” Yet 40 percent support the initiative. (Thirty-eight percent oppose it, while one-fifth are undecided.)

Another poll helps explain the discrepancy. Two-thirds of respondants to the Public Policy Institute of California’s July survey said they support AB 32, but they were split 48 percent to 48 percent over whether the state should act “right away” to lower emissions, or wait until the economy improves.

In other words, Prop. 23 is a referendum not on whether the state’s voters think global warming is a problem, but whether they view pollution control under AB 32’s limited mandate as a drain on the economy.

The opposite, environmentalists argue, is more likely the case. If unabated greenhouse gas emissions drive more droughts, wildfires and crop failures, as scientific models predict, the economic toll is likely to be far steeper than we can imagine.

Maybe what we need is a new proposition altogether.

Weekly Assistant Editor Kera Abraham contributed to this article, which originally appeared in Sacramento News & Review.