Re-assessing Biofuels, an Interview with Dr. David Pimentel | Civil Eats

Re-assessing Biofuels, an Interview with Dr. David Pimentel


If you’ve been listening to the news in the past month, you’ve probably heard quite a bit about biofuels. Simply put, they are fuel made out of plants – principally corn and soybeans in the United States.

The new Obama administration is solidly in favor of increased biofuels production. Everyone from his Secretary of Agriculture to his Secretary of Energy has voiced their support for this policy. But the production of biofuel is by no means uncontroversial, and solidly at the center of this controversy is Dr. David Pimentel, Professor of Ecology and Agricultural Sciences at Cornell University.

Dr. Pimentel was born on a large farm in California’s central valley, and he later moved to a smaller farm in Middleboro, Massachusetts. After his graduate work in entomology at Cornell and post-doctoral work at Oxford University, Massachusetts Institute of Technology, and the University of Chicago, Pimentel got a break when paper on the “life cycle analysis” of corn production was accepted by the journal Science in 1970. He’s been increasingly involved with agricultural issues ever since, and has become one of the most outspoken critics of both industrial farming methods and biofuel production. On both counts, he has published numerous papers demonstrating that modern agricultural technology uses more energy, is more toxic, and provides less benefit to a world of hungry consumers.

Some of his findings are:

1) According to recent analysis, it takes 143% more energy to make one gallon of ethanol than is contained in the ethanol itself.

2) If the entire United States corn crop were used for fuel, it would replace a mere 4% of US oil consumption.

3) One of the possible replacements for corn ethanol is called cellulosic ethanol – made from plant stalks, corn husks and other agricultural waste – but this material is even less efficient than corn and takes even more energy to produce.

4) It currently requires 1,700 gallons of water to produce each gallon of ethanol (mostly to grow the corn.)

His most recent paper Pimentel D et al. Food versus biofuels: environmental and economic costs, published in the journal Human Ecology, is as scathing an indictment of the effects of biofuel policy as a scientific paper can be. He and his coauthors conclude, “Growing crops for biofuel not only ignores the need to reduce fossil energy and land use, but exacerbates the problem of malnourishment worldwide.”

Ironically, in the recent economic environment ethanol production is starting to look a little less rosy for the people who make it, as well. A recent New York Times article details how the “goals lawmakers set for the ethanol industry are in serious jeopardy.” While new ethanol plants were recently being built as fast as possible, the article continued, “the industry is burdened with excess capacity, and plants are shutting down virtually every week.”

I recently caught up with Dr. Pimentel to see what all the fuss was about.

Dr. Pimentel, did you have any idea that this work was going to strike such a strong chord when you did this research a few years ago?

No, I didn’t but that’s what happens when you get mixed up with politics and big money.

But you’ve been working on biofuel issues for quite a few years?

Yes, more than 20 years.

And you’ve gotten some news for your work, but it seems like people on the policy level haven’t listened to what you’ve been saying.

Well, were gaining on the system and getting more and more people to understand the situation, so that’s encouraging.

Have you been contacted by the Obama administration?

Not really, no. And I’m a little disappointed by Obama right now, and the new Secretary of Agriculture Vilsack and Steven Chu, Secretary of Energy, and the Secretary of the Interior Salazar they’ve all expressed support for Ethanol. And that position is clearly not supported by the research.

Can we back up – didn’t your scientific career start out in Entomology?

Yes, that’s true, I started by studying insects but I was an entomologist with broad interests.

So how did you progress from entomology to sustainable agriculture and biofuel research?

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Well, I got involved with energy and agriculture back in the early 1970’s – and we published a paper in Science at that time. Fortunately they accepted it way back then.

And I’m really intrigued by your 2005 study about organic agriculture producing the same yields as conventional?

I’m really proud of that study published jointly with the people at the Rodale Institute.

But with all the current press I’ve seen about your current biofuel paper, I haven’t seen people making the connection between large agribusiness and the biofuel companies?

Well, they all work together to keep the system of subsidies and dependence going. For example, the big chemical companies have definite interests in keeping the chemicals going, and in fact that’s what genetic engineering is about, especially the herbicide resistance. That’s been put into soybeans and corn – in fact 75% of both those crops are now herbicide resistant. And these are the crops that people want to use for fuel. All this does is waste energy and promote the use of herbicides that the chemical companies are most interested in selling.

So that’s what this business is all about. It’s not increasing the yield of corn or soybeans at all, it’s increasing the use of herbicides in soybeans and corn.

And recently I’ve seen advertising that they are making drought resistant GE crops to increase yield, but from what I understand there aren’t any proven crops that are drought resistant?

That is true. When they say they are drought resistant, what they mean is that the crop can wilt better than a conventional crop. But if you look at it, it still takes the same quantity of water to produce the same quantity of corn whether they are drought resistant or not.

In other words, it still takes about 700,000 gallons of water to produce an acre of corn whether it is drought resistant or conventional corn.

So Monsanto’s claim to be able to have a drought resistant corn in the next few years is all talk?

Yes, that’s right.

Do you follow the debate about organic farms with GMO seeds, saying that there isn’t any conflict between organic agriculture with genetically modified seeds?

I don’t agree with the genetically modified organisms, but I am glad that more people are interested in organic and are supporting it.

I certainly don’t want to propose that all organic is going to solve all our problems. There are significant problems with some of our crops – like potatoes, and apples, and oranges and so forth – that have serious pest problems that have to be dealt with.

But the corn and soybeans that we have studied and published in Bioscience was a very fortunate combination. We achieved the same yields of corn and soybeans over a 22 year period, comparing organic with conventional fields. That is very encouraging – using no nitrogen fertilizer, and no insecticides, and no herbicides in this study.

It shows that it can be done, and that we don’t need genetic engineering or chemicals to do it.

Are you following the current drought situation here in the US?

Yes, I have been following it, and it’s also terrible in Australia, too.

Yes, and also in China and South America.

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They are having problems as well. But according to the climatologists, this is a normal amount of precipitation that we’re going to have to get used to. Of course, I hope we go back to the abnormal levels we’ve been having. There’s no question that we need more water.

And again, I emphasize, to grow an acre of corn for the growing season of three months uses 700,000 gallons of water, and that’s an enormous amount of water. Very few people appreciate the amount of water that is required by agriculture.

Out in California, you might have a better appreciation than we do back in the East.

Perhaps more than some. Here in California, it looks like we are going to be forced to drastically reduce our agricultural output this year due to water shortages, and California produces 50% of the national’s row crops. So it’s going to greatly affect our overall food resource in this country, and probably raise prices even in this depressed economy.

Yes, that’s true. So in this economy and environment it’s not a time to grow more crops for fuel. That’s my main point that I’m trying to make. Each gallon of ethanol requires 1,700 gallons of water to produce – we just can’t keep that up.

Did you see the recent USDA Census of Agriculture Report, indicating an increase in the number of small and organic farms?

Yes, and while it is true that the larger farms are producing most of the food, I’m still very supportive of the smaller farms because I was born and brought up on a small farm, so I’m biased. But I think they have a place, and should have a place, and I’m pleased to see that organic is growing.

What do you think is the future of sustainable agriculture?

When you say sustainable, what do you mean?

Exactly! That’s my question for you – what do you mean when you use the term? In general people don’t have a clear definition of that term.

Well, unfortunately, it means everything to everybody.

Do you have a personal definition?

Organic. It’s a simple clear term, if you’re talking about producing crops in an environmentally sound and energetically sound way. And I don’t want to indicate that all organic is easy and successful, because it’s not. But there are some crops such as the corn and soybeans, which are the two major crops in the United States, where organic can be used and be effective.

Photo: jurvetson

Chef / Ecologist Aaron French is the Environment Editor at Civil Eats. He is the chef of The Sunny Side Cafe and is writing his first book "The Bay Area Homegrown Cookbook" (Voyageur Press, 2011). He has a Masters in Ecology and is currently working toward his MBA at UC Berkeley, with a focus on sustainable business practices. Read more >

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  1. Great article. I've been saying since the beginning it's all about the money. Ethinol isn't good for the environment, it's only great for certan people's wallets. I am also dissappointed in the Obama administration for their "greenwashing". They're trying to look like they support the "green" initiative, but they're not focusig on the real issues. At least there are some people seeing it, makes me feel better that there are others out there that are watching this as well.
  2. And yet Monsanto says this:

    By 2030, Monsanto commits to help farmers produce more and conserve more by:

    * Developing improved seeds that help farmers double yields from 2000 levels for corn, soybeans and cotton, with a $10 million grant pledged to improve wheat and rice yields.
    * Conserving resources through developing seeds that use one-third fewer key resources per unit of output to grow crops while working to lessen habitat loss and improve water quality.
    * Helping improve the lives of all farmers who use our products, including an additional five million people in resource-poor farm families by 2020.

    And they have more to claim in their ironically named advertisement "Produce More. Conserve More. Improve Farmers' Lives":

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