Is this fact, cheap food one of the main problems we face in relationship to the environment? Are we running down or environment trying to bring down food price? Big agricultural business are being subsidized and farming has become a mega endeavor driving small farmers out of business. At the same time the real cost of food has been shifted to more transportation, energy and fuel use, and in general environmental degradation that are not included in the price of a lettuce but we all pay one way or another.
A good read for a deeper understanding of how the economy of our society is strongly linked to the environmental framework is Deep Economy by Bill McKibben.