Corn-based ethanol presents problemsWritten by Stephen Roberts | | email@example.com
We are faced with a fossil-fuel challenge we need to address. The United States consumes 25 percent of the world’s oil even though we have just 5 percent of the world’s population. We do not have enough fossil fuel of our own and are increasingly dependent on other countries for this resource. As we continue to increase our consumption of fossil fuels such as gasoline, most scientists agree that we are contributing to global warming.
One of the products that have been developed to cut our reliance on fossil fuel is corn-based ethanol. Many investors and farmers see ethanol production as a very significant financial opportunity, and many new ethanol production facilities are now being built.
Does producing corn-based ethanol to take the place of fossil-based fuels make sense? Many appear to think not.
For one thing, ethanol will not replace fossil fuels. The most optimistic estimates indicate that fuel made from biomass (corn) can replace only 25 to 33 percent of transportation fossil fuel. This percentage will in all likelihood decrease since our demand for fossil fuel for transportation will increase by more than 35 percent by 2030.
The World Resources Institute estimates that our increasing production of corn to produce corn-based ethanol will have a negative impact on soil and water quality. One of the ways to increase corn production is to grow it year after year instead of rotating it with other crops. This will require more fertilizer and pesticide use because of the increasing resistance of weeds and insects to the chemicals meant to control them. These chemicals eventually make their way into our water supply and represent a serious health problem for humans.
The fertilizers used on corn also contribute to increased eutrophication of our water ways. Europhication occurs when too much fertilizer ends up in the water, and plant growth increases to the point that makes it difficult for other forms of life to survive. An area the size of Rhode Island and Connecticut in the Gulf of Mexico already cannot support fish because of the eutrophication effect. Corn is especially problematic in this regard because it is less efficient at absorbing nitrogen from fertilizer and the runoff of fertilizer from corn fields is much greater than other crops.
One of the issues that is often not mentioned in the corn-based ethanol discussion is soil erosion. According to David Pimentel, professor of ecology at Cornell University, “Soil erosion is second only to population growth as the biggest environmental problem the world faces.” Around the world, 30 percent of land suitable for farming has become useless since 1960 due to erosion. According to Pimentel, “Corn production in the U.S. erodes soil about 12 times faster than the soil can be reformed.”
It turns out that corn-based ethanol also presents an air pollution problem. Stanford University atmospheric scientist Mark Z. Jacobson recently carried out a computer simulation comparing the use of gasoline and a popular blend of 85 percent ethanol and 15 percent gasoline (E85). He found that E85 represents at least as great a health problem as gasoline.
It is important that in our transition away from fossil fuel we consider the overall long-term impact of the choices we make. Think of what our great, great grandchildren will think of us if we do not.
Stephen Roberts is an associate professor in the UT Department of Public Health and Homeland Security.