Ronald Bailey exposes the food miles farce:
According to a 2000 study, agriculture was responsible for 7.7 percent of total U.S. greenhouse gas emissions. In that study, food transport accounted for 14 percent of the greenhouse gas emissions associated with agriculture, which means that food transport is responsible for about 1 percent of total U.S. greenhouse gas emissions.
Food miles advocates fail to grasp the simple idea that food should be grown where it is most economically advantageous to do so. Relevant advantages consist of various combinations of soil, climate, labor, capital, and other factors. It is possible to grow bananas in Iceland, but Costa Rica really has the better climate for that activity. Transporting food is just one relatively small cost of providing modern consumers with their daily bread, meat, cheese, and veggies. Desrochers and Shimizu argue that concentrating agricultural production in the most favorable regions is the best way to minimize human impacts on the environment.