Since WWII food production has become completely dependent on petroleum and natrual gas in most of the world. Consider that it takes 10 calories of fossil fuel to produce 1 calorie of food energy. What does that mean in a world of increasingly expensive oil and gas? In this segment we put the question to authors Michael Pollan and Richard Heinberg. Pollan is author of "The Omnivor's Dellema" and Heinberg is author of several books on oil depletion, most recently "The Oil Depletion Protocol."