Ethanol: more than just corn.

• Author: Murray, Danielle
• Position: EYE ON ECOLOGY

AT THE FUEL PUMPS in Sao Paulo, customers have a choice: gas or alcohol. Since the mid 1970s, Brazil has worked to replace imported gasoline with ethanol, an alcohol distilled from locally grown sugarcane. Today, ethanol accounts for 40% of the fuel sold in Brazil.

Ethanol can be produced from a wide variety of plant-based feedstocks, most commonly grain or sugar crops. It then is blended with gasoline as an oxygenate or fuel extender for use in automobiles, or it can be used alone in "flexible-fuel vehicles" that run on any blend of ethanol and gasoline.

Brazil led world ethanol production in 2004, distilling 4,000,000,000 gallons. The U.S. rapidly is catching up, however, producing 3,500,000,000 gallons last year, almost exclusively from corn. China's wheat- and corn-rich provinces produced nearly 1,000,000,000 gallons of ethanol and India turned out 500,000,000 gallons from sugarcane. France, the frontrunner in the European Union's attempt to boost ethanol use, produced over 200,000,000 gallons from sugar beets and wheat. In all, the world produced enough ethanol to displace roughly two percent of total gasoline consumption.

Efforts to substitute alternative fuels for petroleum are gaining attention in a world threatened by climate change, rural economic decline, and instability in major oil-producing countries. Biofuel crops take in carbon dioxide from the atmosphere while they are growing, offsetting the greenhouse gases released when the fuel subsequently is burned. Replacing petroleum with biofuel can reduce air pollution, including emissions of fine particulates and carbon monoxide. Biofuel production also can improve rural economies by creating new jobs and raising farm incomes. As a locally produced, renewable fuel, ethanol has the potential to diversify energy portfolios, lower dependence on foreign oil, and improve trade balances in oil-importing nations.

Although ethanol's popularity is growing, today's inefficient production methods and conversion technologies mean that this fuel only will produce modest environmental and economic benefits and could impinge on international food security. The largest obstacle to biofuel production is land availability. Expanding cropland for energy production likely will worsen the already intense competition for land among agriculture, forests, and urban sprawl. With temperatures rising and water tables falling worldwide, global food supply and demand are precariously balanced. World grain...