THE CALIFORNIA Air Resources Board is devising a plan to reduce the carbon content of the state's engine fuels 10 percent by 2020.
To reach that goal, the air board is considering greater use of alternative fuels such as electricity, hydrogen and biofuels. What California does is likely to drive federal policy on fuels in the future.
However, it is interesting and encouraging that the air board does not see a long-term role for corn-based ethanol. While biofuels show considerable promise to partially replace petroleum, making them from corn is the wrong method.
It takes a lot of energy to produce corn-based ethanol. In fact, it takes one unit of fossil-fuel energy input to create just 1.3 units of corn ethanol energy. That is hardly an efficient way to reduce the use of petroleum or other fossil fuels.
Furthermore, the greenhouse gas emissions emitted from corn ethanol are only 22 percent less than those produced by gasoline.
Ethanol made from sugar cane is far more efficient. For every unit of fossil-fuel energy used to make cane ethanol, eight units of cane ethanol energy are produced. Also, the greenhouse gas emissions from sugar cane ethanol are 56 percent less than from gasoline.
Depending on how it's made, cellulosic ethanol, made from grasses, forestry waste and agricultural residues, could be far more efficient than cane ethanol and have 91 percent less greenhouse gas emissions than gasoline.
Making ethanol from corn also has other adverse effects. It removes agricultural land from other uses. As a result, food prices, especially those that use corn or corn oil, have risen sharply, not to mention the huge taxpayer subsidies required.
Corn-based ethanol has a lot more to do with politics than energy. Massive subsides to farm states during the Bush administration were designed to produce political support, not a greener environment.
The state air board's plan supports biofuels made from sources other than corn, especially cellulosic ethanol, which would not have a major impact on agricultural lands.
When considering alternatives to gasoline and diesel oil, efficiency and environmental impacts must be considered. We are encouraged that the state air board is on the right track in its evaluation of corn ethanol.