Expanding ethanol use will not reduce global warming, bring down gas prices, relieve our dependence on foreign oil, starve terrorists of funding, restore the family farm, or create jobs. In fact, using more ethanol increases greenhouse gas production and local air pollution and is water-intensive as well as land-intensive.

Resident Scholar Kenneth P. Green

Ethanol--the chemical that gives your booze its kick--has been used by mankind for a very long time, 8,000 years or so. Even Stone Age people recognized the value of a good tipple. Of late, ethanol has been touted as the super-fuel that will reduce global warming, bring down gas prices, relieve our dependence on foreign oil, starve terrorists of funding, restore the family farm, create jobs and basically Save The Planet!

Contrary to popular belief, vastly expanding our use of ethanol fuel would do few, if any, of these things. But it almost certainly would increase food prices, greenhouse gas emissions and local air and water pollution while decreasing our supply of fresh water, consuming more of our land and destroying more of our ecosystems.

First, the lack of benefits. While nature spent millions of years concentrating solar energy in the forms of peat, coal, oil and natural gas, ethanol relies on the sunlight that strikes living plants in a single growing season. Because solar energy is diffuse, the scale of land consumption and the labor required to gather massive quantities of vegetation quickly leads to diminishing returns. As Rockefeller University researcher Jesse Ausubel points out, it would take 1,000 square miles of prime Iowa farm land to produce as much electricity from biomass as from a single nuclear power plant.

The highly touted cellulosic ethanol, made from such plants as switch grass, is no solution, either. Professor John Deutch of the Massachusetts Institute of Technology recently showed that we might conceivably produce enough ethanol from cellulose to displace 1 million to 2 million barrels of oil per day in the next couple of decades. But we currently use 20 million barrels a day and have a growing population, so it's clear we're not going to seriously influence world oil markets, become energy independent, impoverish oil-rich enemy regimes or de-fund terrorists by making ethanol.

Now, let's address ethanol's many drawbacks. Ethanol increases greenhouse gas emissions in two ways--by raising the output of the most potent greenhouse gases and by requiring land-clearance, which releases carbon dioxide into the air.

In 1997, the U.S. Government Accountability Office found that the ethanol production process produces more nitrous oxide and other powerful greenhouse gases than does gasoline production. A decade later, Colorado scientists Jan Kreider and Peter Curtiss concluded that carbon dioxide emissions in the production cycle are about 50 percent higher for ethanol than for traditional fossil fuels.

Making ethanol from cellulosic plants such as switch grass, briefly touted by President Bush a couple of years ago, won't help. In February, researcher Timothy Searchinger and colleagues calculated that ethanol from switch grass, if grown on U.S. corn lands, would increase greenhouse gas emissions by 50 percent compared to using regular gasoline.

Then there's local air pollution. The Environmental Protection Agency says using more ethanol fuel would increase ozone-producing chemicals. Mark Jacobson, a researcher at Stanford University, recently estimated that widespread switching to a blend of 85 percent ethanol and 15 percent gasoline might increase ozone-related mortality, hospitalization and asthma by about 9 percent in Los Angeles and 4 percent in the United States as a whole.

Now, let's talk about water consumption. Messrs. Kreider and Curtiss estimate that growing and refining corn for a gallon of corn ethanol today requires about 140 gallons of water. That would mean the 5.4 million gallons of corn ethanol used in America in 2006 required the use of 756 million gallons of fresh water.

Things do not look much better for ethanol made from cellulose crops, which require between 146 and 149 gallons of water per gallon of ethanol fuel, depending on the scale of production. To meet the Bush administration's target of 35 billion gallons of renewable and alternative fuels production in the United States by 2017 with cellulosic ethanol would require as much water as flows in the Colorado River every year.

There's a water pollution issue, as well. The National Academy of Sciences points out that expanding corn-based ethanol production without new environmental protection policies would pose a "considerable" threat to water quality. Corn requires more fertilizers and pesticides than other food or biofuel crops. Pesticide contamination is already highest in the corn belt, and nitrogen fertilizer runoff from corn already produces the most serious agricultural impact on the Mississippi River.

Fertilizer runoff does not just pollute local waters. Each summer, the nitrogen fertilizers in the Mississippi hit the Gulf of Mexico, creating a large dead zone--a region of oxygen-deprived waters unable to support sea life that extends for more than 10,000 square kilometers. The same phenomenon occurs in Chesapeake Bay.

A recent study by researchers at the University of British Columbia shows that if the United States were to meet its proposed ethanol production goals of 15 billion to 36 billion gallons of corn and cellulosic ethanol by 2022, nitrogen flows to the Gulf of Mexico would increase by 10 percent to 34 percent.

Finally, there's land consumption and food prices to consider. In a February Science article, researchers calculated that projected corn ethanol production in 2016 would require 43 percent of the land harvested for corn in 2004 that otherwise was used to feed livestock. This represents an enormous change in land use--to either replace the grain lost to food production by vastly expanding corn fields--or a significant increase in food prices of the sort we've already seen due to scarcity of grain raised for human and livestock consumption.

There is little question that high gasoline and oil prices damage the national economy and the personal economies of individual Americans. But putting our hope in ethanol (whether from corn, switch grass or other cellulosic crops) is not a rational policy response, however attractive it might be to the corn lobby.

Although it is rare for anyone to recommend that lawmakers hit the bottle, in the case of ethanol, the balance of virtue and vice is fairly clear. America's motto should not be "Ethanol for Energy Independence." It should be "Ethanol: Drink It, Don't Drive It."

Kenneth P. Green is a resident scholar at AEI.