This is a good article in the New York Times, April 26, 2008, by Elisabeth Rosenthal with links to other articles, video and audio about the environmental costs for shipping food around the world.
Cod caught off Norway is shipped to China to be turned into filets, then shipped back to Norway for sale. Argentine lemons fill supermarket shelves on the Citrus Coast of Spain, as local lemons rot on the ground. Half of Europe’s peas are grown and packaged in Kenya. More.