A country music star once paraphrased his father, who told him that when you climb high enough up the flagpole, more people can see your backside and will use it as a target.

Biodiesel has reached a new level of visibility, and this is a great achievement. However, with a new level of success comes a new level of opposition.

A recent study published by Cornell Professor David Pimentel and University of California-Berkeley Professor Tad Patzek concluded that biodiesel has a negative energy balance, requiring 27 percent more fossil energy than it generates. This is strange, given that the International Energy Agency recently reviewed nine serious, peer-reviewed, published lifecycle studies on biodiesel, all of which showed extremely positive fossil energy balance. How is it that this one can have such dramatically different conclusions?

One needs only to read the study to see why. The authors appear to go so far out of their way to support their case that it borders on the absurd. For example, the study counts calories consumed by farmers as fossil energy inputs for biodiesel, yet it does not give biodiesel credit for the value of glycerin as a co-product. While soybeans are approximately 80 percent protein meal and 20 percent oil, the study allocates 79 percent of the energy inputs for growing soybeans to the oil. It also uses energy data for growing soybeans from 15 years ago when 2002 data is readily available.

It seems Pimentel has made a career of getting publicity as a biofuel naysayer. Co-author Patzek, by the way, happens to be director of the University of California Oil Consortium.

Ordinarily, this type of flawed science would simply be ignored. However, media and opponents of ethanol have used Pimentel's "data" as evidence of the fallacy of ethanol in energy policy, despite the fact that most serious science shows a positive energy balance for today's ethanol. Pimentel gets plenty of attention and continued grant funding, and opponents of biofuel have their dirty bombs to throw.

Now that biodiesel has climbed higher up the flagpole, Pimentel is setting his sights on it. When anything becomes successful, there are always people who try to tear it down. The National Biodiesel Board, which has earned a reputation as technically conservative and thoroughly credible, rejects his work, as do researchers at the U.S. Departments of Energy and Agriculture.

Bad science has a negative energy balance. It must be confronted and exposed.