Clouding Assumptions

Science magazine this week published an exchange between Vinod Khosla, the venture capitalist who has invested a great deal in alternative energy, and Timothy Searchinger and coauthor Richard Houghton critiquing and defending the February 2008 study, “Use of U.S. Croplands for Biofuels Increases Greenhouse Gases Through Emissions from Land-Use Change” The exchange reveals some of the nuances of indirect land use change arguments that have not been addressed.

Khosla’s comments raise two important issues, allocation and system boundaries, though they go largely unexplored. He writes,

It is inaccurate and misleading to allocate the cutting down of Brazilian rainforest, which is done often for timber production, to biofuels use. The economic signals driving biofuels or agricultural land-use changes are different from the timber-driven economic signals driving land-use change patterns. The deforestation estimates of Searchinger et al. are appropriate for biodiesel production in the Far East.”

Deforestation in Malaysia can be allocated appropriately to biodiesel production, in Khosla’s view, because ecologically sensitive land has been converted to palm oil plantations in part to meet demand for biodiesel. The system boundaries of that supply and demand dynamic are clear. Moving from U.S. biofuel policy, which emphasizes domestic production of biofuel over imports, to deforestation in Brazil is a broader system where responsibility must be allocated more carefully, taking into account the direct causes of deforestation such as Brazilian policy.

In their response, Searchinger and Houghton avoid the problem of allocation and instead raise a moral issue:

Biofuels that use good cropland anywhere in the world raise crop and meat prices and help spur the actual conversion to pasture or cropland by increasing their net economic return.”

The sentence does little to support the theory that U.S. biofuel production is tied indirectly to deforestation in Brazil. What it does is seek to set the system boundary for biofuel production at a worldwide level. In order to examine the effects of U.S. biofuel production in this system, all causes of increased crop and meat prices, as well as all policies to encourage or discourage deforestation, must be taken into account and allocated properly.
Searchinger and Houghton further reveal the moralistic tone of their argument in another part of their response:

Khosla correctly notes the capacity to boost yields in many developing countries, but the world must already unleash that capacity to feed a larger, selectively richer, world population while also reducing deforestation.”

This reminds me of when my mother told me as a child to clean my plate because there were starving children in Bangladesh. It’s a snarky comment, I know, but Searchinger and Houghton are attempting to argue that an interdependent worldwide market for food, land and carbon emissions already exists and can be modeled according to economic equilibrium principles. They need to present more evidence and avoid moral arguments.

No land cleared for biofuels

One of the many flaws of the Science Magazine studies on biofuels and land use changes is their assumption that an acre of crops dedicated to biofuels in America will lead to an acre of deforestation elsewhere in the world. In fact, in a recent interview with the Nature Conservancy (his employer) Joe Fargione, the author of one of the studies, goes well beyond the data supported by his study and claims that “Increased demand for ethanol corn crops in the United States is contributing to conversion of the Brazilian Amazon and Cerrado.” (Emphasis added to show present tense). It would be interesting to see Fargione’s data to support that claim, because I couldn’t find it in his study.

Actually, his claim does not square with the data we have. In a speech to the Global Legislators Organisation for a Balanced Environment (GLOBE), Brazilian President Luiz Inácio Lula da Silva said his country had “60 million hectares (150 million acres) of unused grasslands that have already been deforested and no longer serve as pasture for livestock but can be recuperated for the cultivation of sugar cane and oilseeds to produce biodiesel.” According to the book Break Through, 52,000 square miles (33 million acres) were deforested in Brazil from 2002-2005, when a bushel of corn was trading for around $2. In fact, 317,000 square miles (202 million acres) of Brazilian rainforest were destroyed well before the current increase in commodity prices. Why, you might ask?

Rather than relying on modeling, let’s get the word from someone on the ground in Brazil. Peter Zuurbier, an Associate Professor located in Piracicaba, said that “deforestation leads to soybean production near the Amazon, not the other way around.” In other words, Fargione, et. al. got the correlation correct, but botched causation. Zuurbier describes what’s actually happening in Brazil:

Well organized groups and corporations with questionable land titles, but also official land owners began to chop down large acreages of forest to trade timber, both legally and illegally. Usually, after the empty strips of land were abandoned, cattle owners would move into these cheap lands. However, after 3 to 4 years of cattle breeding, the thin soil of the Amazon is completely useless without any form of fertilization and livestock owners usually move into the next abandoned area. Soybean farmers meanwhile replace the livestock in these areas, recognizing the opportunity to fertilize the area for soybean production.

So, do we blame the producers of soybeans for being the last line in that chain of events? Wouldn’t it be better to plant a crop like soybeans on that ground rather than leave it barren?

An additional problem with Fargione’s claim is that agricultural and distillers grains exports are higher than ever before in history. That’s what led Dr. Michael Wang, the researcher at Argonne’s Transportation Technology R&D Center who created the GREET LCA model for biofuels, to conclude:

There has also been no indication that U.S. corn ethanol production has so far caused indirect land use changes in other countries because U.S. corn exports have been maintained at about 2 billion bushels a year and because U.S. DGS exports have steadily increased in the past ten years.

So, while there is nothing to support Fargione’s claim of biofuels causing deforestation in the Amazon, there is plenty of evidence to suggest that it’s not and that it won’t need to for a long time.