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Debunking Searchinger’s Doomsday Theories…Again

January 30, 2015


A new paper written for World Resources Institute (WRI) by Timothy Searchinger and Ralph Heimlich falsely claims that expansion of crop- and forestry-based bioenergy will exacerbate climate change and global food insecurity. The paper makes two central arguments, both of which have been made (and thoroughly discredited) in previous papers by the authors. The first major assertion is that existing land resources are simply unable to produce enough animal feed to satisfy future global meat demand, and that using even a small fraction of land for bioenergy "diverts" crops away from feed markets. Searchinger argues that the "displaced" feed crops must be grown somewhere else in the world, causing native ecosystems—which serve as important carbon sinks—to be converted to cropland. In essence, this is the "food versus fuel" theory and "indirect land use change" concept rolled into one. The second major argument is that there is an "accounting error" associated with bioenergy lifecycle carbon analysis. Searchinger and Heimlich state that when the error is "corrected," biofuels are no better for the climate than fossil fuels. Both of these false assertions are addressed in more detail below. Food vs. Fuel and ILUC Revisited The new WRI paper suggests that "...bioenergy that entails the dedicated use of land will undercut efforts to combat climate change and to achieve a sustainable food future." If these claims sound familiar, it's because they first appeared in a 2008 paper by Searchinger, Heimlich and others in the journal Science. In that paper, they suggested that biofuels expansion under the Renewable Fuel Standard (RFS) would lead to "reduced food consumption" globally and massive carbon emissions from "land use change." Those claims have been proven wrong in the years since the paper was published, meaning similar arguments in the new paper should be looked upon with great skepticism. Recent data and analyses show the fallacy of the Searchinger and Heimlich arguments regarding the impact of biofuels on food security and land use.
  • The latest estimates from the United Nations' Food & Agriculture Organization (FAO) reveal that major strides have been made to improve global food security during the period in which biofuels production has expanded. According to FAO, the food supply per person globally is at record levels, as is per capita protein supply.
  • A 2014 FAO publication indicates that " hunger reduction continues" and shows global hunger fell by 21% between 1990-92 and 2012-14.
  • According to FAO, "In the same period, the prevalence of undernourishment has fallen from 18.7 to 11.3 percent globally and from 23.4 to 13.5 percent for the developing countries."
  • FAO and others have found that the most significant food security challenge facing the world is not food scarcity, but rather food loss and waste. According to FAO, "...roughly one-third of food produced for human consumption is lost or wasted globally, which amounts to about 1.3 billion tons per year." Thus, the amount of food wasted every year is nearly equivalent to the global supply of coarse grains (corn, oats, barley, sorghum, rye, millet).
  • Searchinger contended in 2008 (and again in the WRI paper) that grain would be "diverted" away from food and feed markets to make biofuels. However, data show that even after accounting for the grain used for biofuels, there is more grain available today for food and feed use than at any time in history. In other words, the world grain supply has grown large enough to satisfy both increased demand for food and animal feed, as well as increased biofuel production.
  • The new WRI paper revives the argument from the 2008 Science article that "Higher prices triggered by biofuels will accelerate forest and grassland conversion..." However, empirical data show that deforestation and native grassland conversion rates have slowed significantly since the RFS was adopted. And in many regions around the world, cropland has decreased—not expanded—over the past decade. Similarly, many regions have seen increases—not reductions—in forestland over this period.
  • In fact, a recent study by economists at Iowa State University (whose economic model was used for the 2008 Searchinger analysis) found that "...the primary land use change response of the world's farmers in the last 10 years has been to use available land resources more efficiently rather than to expand the amount of land brought into production."  Farmers around the world have responded to increased demand for crops and higher prices by applying more efficient practices—such as double-cropping—to existing cropland.
  • Since Searchinger published the 2008 paper, the scientific community has gained a much better understanding of actual responses to increased crop demand and higher prices. As a result, the Department of Energy's current estimates of potential land use change emissions are equivalent to just 8% of Searchinger's astronomically inflated original estimate.
  • In reference to the 2008 Searchinger article, the Union of Concerned Scientists (UCS) wrote just last week that "The headline 7 years ago – that crop-based biofuels are far worse than fossil fuels – no longer holds." UCS wrote that the 2008 Searchinger paper "...has not survived careful scrutiny. Subsequent analyses found more flexibility in the agricultural system to expand production without large increases in deforestation, and deforestation in Brazil has slowed."
  • While Searchinger and Heimlich appear to briefly acknowledge that growth in crop yields can alleviate pressure on land resources, it seems they essentially ignored yield growth in their calculations of the 2050 "calorie gap." The average corn yield per acre in the U.S. has essentially doubled in the last 40 years and there is a significant body of research suggesting yields may double again by mid-century.
  • As a result of yield growth and more efficient land use, the existing agricultural land base could support a far larger population, according to experts. When asked recently by NPR if the world has enough land to feed the projected population of 10 billion people in 2100 if certain dietary changes are made, renowned agricultural economist Bruce Babcock stated, "We would have more land available for the 10 billion than they would know what to do with."
  • Even if additional cropland is needed to support both food and bioenergy demands moving forward, a number of researchers have found that there is a substantial amount of arable land available that is suitable for crop production without needing to convert sensitive ecosystems.
Fixing a Carbon Accounting "Error" That Doesn't Exist The second major assertion made by the new WRI paper is that bioenergy, in general, is no better for the climate than fossil fuels because both emit similar quantities of carbon dioxide (CO2) when combusted, and because the biomass would have absorbed CO2 from the atmosphere even if it wasn't being used for bioenergy. Searchinger and Heimlich claim that it is an "accounting error" to assume that biomass combustion emissions are offset by CO2 uptake during photosynthesis. This is not a new argument from Searchinger. In fact, he made the same allegation in the 2008 Science article, in memos to Congressional leaders in early 2009 (designed to derail progress on the House climate change bill), and in a 2009 essay published in Science.  In each case, the scientific community swiftly and strongly rebuked the argument and clearly justified the internationally accepted carbon accounting conventions. The fallacy of Searchinger's carbon accounting argument is quite easy to see: he fails to appropriately compare the full biomass carbon cycle to the carbon cycle of fossil fuels. In a case where the biofuels carbon cycle is directly compared to the fossil fuels carbon cycle, the benefits of using biomass are blatantly obvious. Crops used for biofuels act as temporary carbon sinks; during photosynthesis, they quickly absorb CO2 that was just in the atmosphere. The CO2 is then returned to the atmosphere when the carbon in the crop is combusted for energy. In this way, the use of biomass for energy recycles atmospheric carbon as part of a relatively rapid cycle. In contrast, the use of fossil fuels adds to atmospheric CO2 levels by emitting carbon that was previously sequestered deep underground for millions of years. The fossil fuels lifecycle does not include the ability to naturally re-sequester carbon emitted by combustion. At some point, the accumulation of these additive emissions from fossil fuels will overwhelm the capacity of existing carbon sinks. A recent paper by scientists at Duke University, Oak Ridge National Laboratory, and the University of Minnesota compared the lifecycle environmental impacts of ethanol and gasoline, finding that: A critical temporal distinction exists when comparing ethanol and gasoline life-cycles. Oil deposits were established millions of years in the past. The use of oil transfers into today's atmosphere GHGs that had been sequestered and secured for millennia and would have remained out of Earth's atmosphere if not for human intervention. While the production and use of bioenergy also releases GHGs, there is an intrinsic difference between the two fuels, for GHG emissions associated with biofuels occur at temporal scales that would occur naturally, with or without human intervention. ...Hence, a bioenergy cycle can be managed while maintaining atmospheric conditions similar to those that allowed humans to evolve and thrive on Earth. In contrast, massive release of fossil fuel carbon alters this balance, and the resulting changes to atmospheric concentrations of GHGs will impact Earth's climate for eons. [1] (emphasis added) Conclusion: Standard Bearers for the Neo-Malthusian Movement? For centuries, social commentators have suggested the world's resources are being pushed passed their limits and that the planet is on the verge of catastrophe.  In the late 18th century, Thomas Malthus suggested population growth in the 1800s would push the world's people into cataclysmic famine and disease. Despite more than two centuries of being proven horribly wrong, Malthus's views were adopted in the late 1960s by entomologist Paul Ehrlich who predicted a "substantial increase in the world death rate" in the 1970s due to starvation. In the 1980s and 1990s, biofuel antagonists Lester Brown and David Pimentel espoused similar opinions. And now, Searchinger and Heimlich have emerged as the standard bearers of the Malthusian movement in the new millennium. Just as the passage of time has exposed the absurdity of the theories of Malthus and Ehrlich, so too will it uncover the irrationality of this latest work by Searchinger and Heimlich.
[1] Parish et al. (2012). "Comparing Scales of Environmental Effects from Gasoline and Ethanol Production." Environmental Management, 50 (6): 979-1246.