Biofuel Skeptic Extraordinaire

A Grist interview with David Pimentel

By Tom Philpott

08 Dec 2006

Any worthy idea can withstand and even be improved by naysayers; scolds and skeptics play the useful role of pointing out obvious flaws. The biofuels industry has no more persistent, articulate, and scathing critic than David Pimentel, professor emeritus of entomology at Cornell University.

David Pimentel.

Photo: Chris Hallman / Cornell University Photography.

In 1979, with the price of oil surging and a politically connected company called Archer Daniels Midland investing heavily in ethanol production, the U.S. Department of Energy invited Pimentel to chair an advisory committee to look at ethanol as a gasoline alternative. The committee's conclusion: ethanol requires more energy to produce than it delivers.

That assessment didn't stop the government from enacting a variety of subsidies for ethanol, which has since developed into a multibillion-dollar industry. Nor has Pimentel refrained from issuing a series of scholarly articles claiming to show that, after decades of steady government support, ethanol remains an energy bust.

Over the years, Pimentel has become an increasingly controversial figure. The U.S. Department of Agriculture now claims that corn ethanol delivers a modestly positive net energy balance [PDF], a conclusion recently endorsed by a study from University of Minnesota researchers. Yet Pimentel's provocations continue. Not only is corn-based ethanol a net energy consumer, he says, but cellulosic ethanol -- simultaneously biofuel's holy grail and sacred cow -- is "worse."

Grist recently spoke to Pimentel about why he thinks biofuels are an environmental dead end. Enthusiasts for crop-based energy would do well to at least examine his analysis.

READ THE INTERVIEW