Does the World Face Another Food Crisis?

Two years ago, a combination of natural events and economic conditions drove food prices so high that food riots erupted in many parts of the world. While the ravages of 2008 aren't yet over, this year, there's concern that the same thing may be happening again. The UN says: Be Prepared. Drought has led Russia to ban wheat exports; America's corn harvest is down and climate change is helping to drive world prices higher. Meantime, farmers make more by using their land for sugar, cotton, soya and bio-fuels. Is industrialized agriculture at fault? What are the prospects of another global food crisis, and what are the chances of heading it off?