CAST paper says 2050 food, fuel needs can be met

By Susanne Retka Schill | March 20, 2013

The world will be capable of meeting its needs for food, fuel and fiber in 40 years, according to a paper from the Council for Agricultural Science and Technology, “Food, Fuel, and Plant Nutrient Use in the Future.”  

Looking ahead to 2050, the paper finds that adequate world food production cannot depend up an expansion of harvested area, however. “Instead, scientists and food producers need to look at the way land is currently used and the best practices for how to move forward,” the CAST committee said. The paper examines population dynamics, food demand, land use and productivity and the impact of energy and biomass production. The authors include David Zilberman, department of agricultural and resource economics, University of California-Berkeley, Bruce Dale, department of chemical engineering and materials science, Michigan State University, Paul Fixen, International Plant Nutrition Institute, Brookings, S.D., and John Havlin, department of soil science, North Carolina State University.

The authors suggest that current U.S. growth rates in cereal grain yields should meet 2050 demands through the use of fertilizer nutrients, advances in genetics and improved oil and crop management technologies. Because future increases in food production will come from increased yield per unit of land area instead of increased arable land area, the paper says, “it is imperative that efforts to sustain and enhance soil productivity be increased, especially in developing countries.”  

In the section on energy use and demand, the authors say that the “the age of stable, cheap oil is over” and, as fossil fuel supplies shrink relative to demand, price volatility is likely to increase. “The world has had cheap food in no small part because it has had cheap energy, led by cheap oil. The production, processing, and distribution of all agricultural and food commodities are intimately linked with the price of energy.”

The goal of biofuels production, they write, is to provide a liquid fuel substitute for petroleum.  And they add that discussions on net energy need to be properly analyzed. “Ethanol produces more than 20 times more liquid fuel per unit of petroleum ‘invested’ to make than is produced in converting petroleum to gasoline. In essence, bioethanol stretches domestic petroleum supplies into the future by leveraging oil to make much more liquid fuel: ethanol.”

The authors also examine the food versus fuel discussion. “This issue of food versus fuel requires careful thinking because it offers potentially important synergies between food and biofuel production. Throughout the United States and much of the rest of the world, people do not actually ‘grow food.’ Instead, they grow animal feed and then consume the meat, milk, eggs, and so forth produced by the animals. Approximately 85–90 percent of the best U.S. agricultural land—more than 300 million hectares of cropland and pasture—is used to feed animals, not directly to feed humans.”

The authors offer scenarios that would expand the supply of animal feed on the same amount of land through the synergies offered by cellulosic biofuel production. “The same facility that produces pretreated feedstock for biofuel production may be able to produce enhanced ruminant animal feedstock,” they write. Biofuel production would allow the early harvest of feedstocks such as alfalfa and grasses when the protein content is high, utilizing the cellulosic fraction for biofuel production and concentrating the protein for animal feed. Additional feed protein can be coproduced with biofuels via the spent yeast, they add.

“Therefore, it is likely that increased cellulosic biofuel production will be accompanied by large increases in quantities of ruminant animal feeds, leading to an increase in both protein and digestible energy. The effect of these two changes will be to use land more efficiently to meet both food (actually animal feed) and biofuel needs.”

On top of that would be the conservation benefits that could be realized by winter cover crops and new double cropping opportunities offered by biofuel feedstock production. One analysis cited in the CAST paper showed that the total biomass production potential, including both grain and cellulosic biomass, could be increased 2.5 times over current levels. “This is enough biomass to produce approximately 400 gigaliters of ethanol per year, roughly the energy equivalent of all imported petroleum used for gasoline production, while still providing all the food and feed currently produced on this acreage. This approach to integrated food and biofuel production also decreases total U.S. GHG emissions by approximately 700 teragrams (Tg) carbon dioxide (CO2) equivalents per year, roughly 10 percent of the total U.S. greenhouse gas emissions.”

An expansion of biomass production for food and fuel will require close attention to plant nutrient needs, the paper concludes. “There is an urgent need to support research and development to decrease total land requirements for biofuel production by integrating animal feed production with cellulosic biofuel production and to recover and recycle key plant nutrients during biofuel production.”