When you start talking energy and environment, ethanol is often touted as a great solution. The abundance of corn in the United States makes ethanol a good way for us to depend less on foreign oil. It’s also been an economic boon for Illinois, which is second in U.S. states for ethanol production. But Robert Glennon, a professor of public policy at the University of Arizona, says there are big drawbacks. He is the author of Unquenchable: America’s Water Crisis and What To Do About It.