California regulators Thursday issued a far-reaching proposal to slash carbon emissions from transportation fuels, setting the stage for a national battle over how to reduce the damage to the global climate from gasoline and diesel combustion.
The low-carbon fuel standard, if approved next month by the state's Air Resources Board, would be the first in the nation to restrict greenhouse gases produced by a fuel, from its source to its burning.
Eleven states are considering similar rules, and President Obama has called for a national low-carbon fuel standard as part of his initiative to cut U.S. greenhouse gas emissions by 80% by mid-century.
Air board chairwoman Mary Nichols said the proposed rule was a "comprehensive, cradle-to-grave approach" that would spur innovation and competition in the alternative fuels market.
But some members of California's beleaguered renewable-fuels industry greeted the initiative with outrage. Tom Koehler, spokesman for Pacific Ethanol, said the proposal was "a perversion of science and a prescription for disaster."
California is the first state to pass a comprehensive law to restrict carbon dioxide and other emissions across its economy. Transportation accounts for one-third of the nation's greenhouse gas releases. Scientists say the emissions are trapping heat in the Earth's atmosphere and changing its climate, which will cause droughts, floods, water shortages and species extinctions.
The fuel standard is a key element in the state's climate plan, along with an initiative to regulate the engines and bodies of vehicles for carbon emissions. That proposal is under review by the federal Environmental Protection Agency.
The fuel proposal announced Thursday is projected to reduce carbon emissions by 16 million metric tons by 2020. It would result in the replacement of 20% of the fossil fuel used by California cars with cleaner alternatives by 2020, including electricity, biofuels, hydrogen and other options, the board said.
By forcing refineries, producers and importers to reduce the "carbon intensity" of their fuel by 10% by 2020, and by increasing percentages after that, the air board is taking a far different approach from the Renewable Fuels Standard that President Bush pushed through Congress in 2007.
That law required that 36 billion gallons of biofuels be sold by 2022, of which 15 billion could be ethanol derived from corn. That rule, said Daniel Sperling, an air board member and a UC Davis transportation fuel expert, spurred "a massive expansion of corn ethanol."
The corn from which ethanol is derived requires large amounts of water and petroleum-based fertilizer to produce and, according to some studies, diverts land from pastures and rain forests, which store carbon. The result is increased carbon in the atmosphere.
In its proposal, the air board seeks to quantify these so-called "indirect land use changes," a calculation that effectively assigns a high carbon intensity to corn-based ethanol in relation to other fuels.
That decision has touched off a furious debate among scientists, some of them industry-supported and others with environmental affiliations. A letter criticizing the air board's methods, released by the New Fuels Alliance, an ethanol industry group, was signed by 111 scientists, including researchers at Sandia National Laboratories and Lawrence Berkeley National Laboratories.
Several missives supporting the air board's approach were signed by leading California energy academics, including UC Berkeley's Daniel Kammen and Michael O'Hare.
The push for ethanol as an alternative to imported oil spurred the construction of 172 plants in 25 states by the end of 2008. But in recent months falling oil prices has made ethanol less cost effective. More than 20 plants have closed, including five in California.
"The proposed regulation will do nothing to start them back up," said Gary Meltz of the fuels alliance. "It would be devastating nationally because . . . as goes California, so goes the nation on many environmental standards and regulations."
But environmentalists praised the rule as the only fair approach. "It's a complicated issue, but the basic principle is simple," said Patricia Monahan, a vehicles expert at the Union of Concerned Scientists. "Set a performance standard, let fuels compete in the marketplace to meet the standard, and keep politics from distorting the science. It's about reducing carbon, not picking winners or losers."