The debate over whether biofuels are good for the environment used to hinge on the credibility of studies published by David Pimentel, professor of ecology at Cornell University, who concluded that it took much more energy or fossil fuel to grow, transport, and process corn into ethanol than the ethanol could ever hope to replace as transportation fuel. A preponderance of other studies on the issue found the data and methods used by Pimentel to be suspect, and most concluded that biofuels generally, and corn ethanol specifi cally, have a positive net energy balance, and their use as a replacement for gasoline leads to a reduction in greenhouse gas emissions.