How Biofuels Could Starve the Poor

C. Ford Runge and Benjamin Senauer

From Foreign Affairs, May/June 2007

Summary:  Thanks to high oil prices and hefty subsidies, corn-based ethanol is now all the rage in the United States. But it takes so much supply to keep ethanol production going that the price of corn -- and those of other food staples -- is shooting up around the world. To stop this trend, and prevent even more people from going hungry, Washington must conserve more and diversify ethanol's production inputs.

C. Ford Runge is Distinguished McKnight University Professor of Applied Economics and Law and Director of the Center for International Food and Agricultural Policy at the University of Minnesota. Benjamin Senauer is Professor of Applied Economics and Co-director of the Food Industry Center at the University of Minnesota.

Participants in the 1996 World Food Summit set out to cut the number of chronically hungry people in the world -- people who do not eat enough calories regularly to be healthy and active -- from 823 million in 1990 to about 400 million by 2015. The Millennium Development Goals established by the United Nations in 2000 vowed to halve the proportion of the world's chronically underfed population from 16 percent in 1990 to eight percent in 2015. Realistically, however, resorting to biofuels is likely to exacerbate world hunger. Several studies by economists at the World Bank and elsewhere suggest that caloric consumption among the world's poor declines by about half of one percent whenever the average prices of all major food staples increase by one percent. When one staple becomes more expensive, people try to replace it with a cheaper one, but if the prices of nearly all staples go up, they are left with no alternative.

In a study of global food security we conducted in 2003, we projected that given the rates of economic and population growth, the number of hungry people throughout the world would decline by 23 percent, to about 625 million, by 2025, so long as agricultural productivity improved enough to keep the relative price of food constant. But if, all other things being equal, the prices of staple foods increased because of demand for biofuels, as the IFPRI projections suggest they will, the number of food-insecure people in the world would rise by over 16 million for every percentage increase in the real prices of staple foods. That means that 1.2 billion people could be chronically hungry by 2025 -- 600 million more than previously predicted.

The world's poorest people already spend 50 to 80 percent of their total household income on food. For the many among them who are landless laborers or rural subsistence farmers, large increases in the prices of staple foods will mean malnutrition and hunger. Some of them will tumble over the edge of subsistence into outright starvation, and many more will die from a multitude of hunger-related diseases.

THE GRASS IS GREENER

And for what? Limited environmental benefits at best. Although it is important to think of ways to develop renewable energy, one should also carefully examine the eager claims that biofuels are "green." Ethanol and biodiesel are often viewed as environmentally friendly because they are plant-based rather than petroleum-based. In fact, even if the entire corn crop in the United States were used to make ethanol, that fuel would replace only 12 percent of current U.S. gasoline use. Thinking of ethanol as a green alternative to fossil fuels reinforces the chimera of energy independence and of decoupling the interests of the United States from an increasingly troubled Middle East.

Should corn and soybeans be used as fuel crops at all? Soybeans and especially corn are row crops that contribute to soil erosion and water pollution and require large amounts of fertilizer, pesticides, and fuel to grow, harvest, and dry. They are the major cause of nitrogen runoff -- the harmful leakage of nitrogen from fields when it rains -- of the type that has created the so-called dead zone in the Gulf of Mexico, an ocean area the size of New Jersey that has so little oxygen it can barely support life. In the United States, corn and soybeans are typically planted in rotation, because soybeans add nitrogen to the soil, which corn needs to grow. But as corn increasingly displaces soybeans as a main source of ethanol, it will be cropped continuously, which will require major increases in nitrogen fertilizer and aggravate the nitrogen runoff problem.

Nor is corn-based ethanol very fuel efficient. Debates over the "net energy balance" of biofuels and gasoline -- the ratio between the energy they produce and the energy needed to produce them -- have raged for decades. For now, corn-based ethanol appears to be favored over gasoline, and biodiesel over petroleum diesel -- but not by much. Scientists at the Argonne National Laboratory and the National Renewable Energy Laboratory have calculated that the net energy ratio of gasoline is 0.81, a result that implies an input larger than the output. Corn-based ethanol has a ratio that ranges between 1.25 and 1.35, which is better than breaking even. Petroleum diesel has an energy ratio of 0.83, compared with that of biodiesel made from soybean oil, which ranges from 1.93 to 3.21. (Biodiesel produced from other fats and oils, such as restaurant grease, may be more energy efficient.)

Similar results emerge when biofuels are compared with gasoline using other indices of environmental impact, such as greenhouse gas emissions. The full cycle of the production and use of corn-based ethanol releases less greenhouse gases than does that of gasoline, but only by 12 to 26 percent. The production and use of biodiesel emits 41 to 78 percent less such gases than do the production and use of petroleum-based diesel fuels.

Another point of comparison is greenhouse gas emissions per mile driven, which takes account of relative fuel efficiency. Using gasoline blends with 10 percent corn-based ethanol instead of pure gasoline lowers emissions by 2 percent. If the blend is 85 percent ethanol (which only flexible-fuel vehicles can run on), greenhouse gas emissions fall further: by 23 percent if the ethanol is corn-based and by 64 percent if it is cellulose-based. Likewise, diesel containing 2 percent biodiesel emits 1.6 percent less greenhouse gases than does petroleum diesel, whereas blends with 20 percent biodiesel emit 16 percent less, and pure biodiesel (also for use only in special vehicles) emits 78 percent less. On the other hand, biodiesel can increase emissions of nitrogen oxide, which contributes to air pollution. In short, the "green" virtues of ethanol and biodiesel are modest when these fuels are made from corn and soybeans, which are energy-intensive, highly polluting row crops.

The benefits of biofuels are greater when plants other than corn or oils from sources other than soybeans are used. Ethanol made entirely from cellulose (which is found in trees, grasses, and other plants) has an energy ratio between 5 and 6 and emits 82 to 85 percent less greenhouse gases than does gasoline. As corn grows scarcer and more expensive, many are betting that the ethanol industry will increasingly turn to grasses, trees, and residues from field crops, such as wheat and rice straw and cornstalks. Grasses and trees can be grown on land poorly suited to food crops or in climates hostile to corn and soybeans. Recent breakthroughs in enzyme and gasification technologies have made it easier to break down cellulose in woody plants and straw. Field experiments suggest that grassland perennials could become a promising source of biofuel in the future.