As you can see, the first three colors--the ones that cover the greenhouse gas impact of the transportation of the food from the farm to the supermarket--are just a small sliver compared to the amount of greenhouse gases emitted during food production. In fact, according to this report, a mere 11% of greenhouse gases emitted because of food consumption are attributable to the transportation of the food. And so this whole "locavore" movement, while tasty, does not have much of a ecological impact.
If you really want to cut back on the ecological impact of your diet, you'd do well to keep cows out of the picture, as they account for about half of all greenhouse gases emitted from food production:
So all you vegetarians out there, this is your free pass to take longer, hotter showers.
Ok that got weird.
EDIT: Eric sensibly asks how much of the total greenhouse gas emissions are caused by food. The report says: "For perspective, food accounts for 13% of every U.S. household's 60 t share of total U.S. emissions; this includes industrial and other emissions outside the home." So food transportation accounts for 11% of 13%, or 1.4% of every U.S. household's emissions.
