"Full Planet, Empty Plates: Chapter 4. Food or Fuel?" Lester Brown grist.org

 "The grain turned into ethanol in the United States in 2011 could have fed, at average world consumption levels, some 400 million people. But even if the entire U.S. grain harvest were turned into ethanol, it would only satisfy 18 percent of current gasoline demand."

"Not only are biofuels helping raise food prices, and thus increasing the number of hungry people, most make little sense from an energy efficiency perspective."

"One of the consequences of integrating the world food and fuel economies is that the owners of the world’s 1 billion motor vehicles are pitted against the world’s poorest people in competition for grain. The winner of this competition will depend heavily on income levels. Whereas the average motorist has an annual income over $30,000, the incomes of the 2 billion poorest people in the world are well under $2,000.

Rising food prices can quickly translate into social unrest. As grain prices were doubling from 2007 to mid-2008, food protests and riots broke out in many countries. Economic stresses in the form of rising food prices are translating into political stresses, putting governments in some countries under unmanageable pressures. The U.S. State Department reports food unrest in some 60 countries between 2007 and 2009. Among these were Afghanistan, Yemen, Ethiopia, Somalia, Sudan, the Democratic Republic of the Congo, and Haiti."

"Yet for the foreseeable future, production of those cellulose-based fuels has little chance of reaching such levels. Producing ethanol from sugars or starches like corn or sugarcane is a one-step process that converts the feedstock to ethanol. But producing ethanol from cellulosic materials is a two-step process: first the material must be broken down into sugar or starch, and then it is converted into ethanol. Furthermore, cellulosic feedstocks like corn stalks are much bulkier than feedstocks like corn kernels, so transporting them from distant fields to a distillery is much more costly. Removing agricultural residues such as corn stalks or wheat straw from the field to produce ethanol deprives the soil of needed organic matter.

The unfortunate reality is that the road to this ambitious cellulosic biofuel goal is littered with bankrupt firms that tried and failed to develop a process that would produce an economically viable fuel. Despite having the advantage of not being directly part of the food supply, cellulosic ethanol has strong intrinsic characteristics that put it at a basic disadvantage compared with grain ethanol, so it may never become economically viable."

http://grist.org/article/full-planet-empty-plates-chapter-4-food-or-fuel/