Gov. Brown could call for ballot measure on climate change

California Gov. Jerry Brown gestures while delivering the keynote address at the Subnational Clean Energy Ministerial in San Francisco in June. Oil companies say they are in talks with Gov. Jerry Brown's administration about changes to the state's carbon-emissions programs, including his vaunted program requiring companies to buy pollution credits. less California Gov. Jerry Brown gestures while delivering the keynote address at the Subnational Clean Energy Ministerial in San Francisco in June. Oil companies say they are in talks with Gov. Jerry Brown's ... more Photo: Eric Risberg, Associated Press Photo: Eric Risberg, Associated Press Image 1 of / 23 Caption Close Gov. Brown could call for ballot measure on climate change 1 / 23 Back to Gallery

Gov. Jerry Brown may ask California voters to extend the state’s climate-change programs — including its pioneering cap-and-trade system — past 2020 if balking state legislators don’t do so this month, one of his top aides said Thursday.

Brown has staked much of his political legacy on the fight against global warming, aiming to slash California’s greenhouse-gas emissions 40 percent below 1990’s levels by the year 2030.

But the landmark 2006 law that created many of California’s climate programs spelled out specific emission cuts only through 2020. And the state’s legislative analyst has warned that California’s cap-and-trade system for limiting emissions may lack legal authorization to keep running after that year.

Brown has been pushing behind the scenes for legislation that would enshrine his 2030 emissions cuts into law and give cap and trade explicit authority to continue. But with the legislative session due to end this month, he has faced stiff resistance from the oil industry and its allies in Sacramento.

So on Thursday, one of Brown’s key advisers, Nancy McFadden, suggested the governor may take the fight directly to California voters.

“Let’s be clear: We are going to extend our climate goals and cap-and-trade program — one way or another,” she wrote in a statement posted on Twitter. “The Governor will continue working with the Legislature to get this done this year, next year or on the ballot in 2018.”

A poll released last month by the Public Policy Institute of California found that 68 percent of Californians supported extending the state’s climate policies and aiming for Brown’s 2030 target.

Launched in 2012, California’s cap-and-trade system places an annual limit on emissions of carbon dioxide and other heat-trapping gases, with the amount of greenhouse gases allowed shrinking each year.

Companies that own power plants, factories and oil refineries must buy a permit — called an allowance — for every ton of greenhouse gases they emit. They can also sell those allowances back-and-forth among one another. The number of permits made available by the state shrinks every year along with the cap, prompting companies to cut their emissions.

The state agency that created the system, the California Air Resources Board, argues that it has legal authority to extend the system past 2020. But others aren’t sure. The state legislative analyst in April warned that California’s 2006 climate law, AB32, authorizes the program only through Dec. 31, 2020.

In addition, a long-running lawsuit filed by the California Chamber of Commerce argues that the allowances are in reality a tax on businesses and should have required a two-thirds vote of the Legislature to take effect.

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As a result, Brown has been pushing for legislation that would extend the program, hoping to lock up the support of two-thirds of legislators in case the Chamber wins its suit. But lobbyists say he has had a tough time persuading Republicans and moderate Democrats.

Environmentalists have been rallying around a bill from Sen. Fran Pavley, D-Agoura Hills (Los Angeles County), that would write Brown’s 40 percent reduction target into law. But so far, that bill does not explicitly authorize the cap-and-trade system to continue.

Uncertainty about its future may already be undercutting the system. When the state held its quarterly allowance auction in May, buyers purchased just 11 percent of the allowances available. Almost every previous allowance auction sold out.

“We need to part the clouds of uncertainty, and there’s nothing like a statute to provide clarity,” said Alex Jackson, legal director of the California Climate Project at the Natural Resources Defense Council.

David R. Baker is a San Francisco Chronicle staff writer. Email: dbaker@sfchronicle.com Twitter: @DavidBakerSF