Simona Drevensek: Biofuels, rising food prices and the lowest stocks of of food in decades in

In 2008, many economists were surprised by the rising prices of maize, rice, wheat and petroleum, all of which tripled in real terms. Prices came down, but ever since, it’s been a rocky road.

Blame part of it on an increase in demand and natural disasters. Floods in Australia, drought in Argentina, fires in Russia, and frost damage in the U.S. and Europe contributed to the spike in food prices in December 2010, according to the Food and Agriculture Organization (FAO). These events resulted in export bans and short-term speculation, causing riots and political instability in more than 30 countries worldwide.

But part of the problem derives from ethanol production. In the U.S., 40% of corn production from food and feed is used for ethanol fuel production, putting stress on corn supplies in a year when stocks are at the lowest level in decades. People living in the 52 high-risk countries -- 750 million of them already malnourished -- rely on 83 billion tons of imported food a year, much of it corn, soybeans and wheat exported by the United States.