A recent study questioning the value of eating locally has been getting quite a bit of press lately. The study argues that the actual transportation of foot produces very little carbon, and that most of the carbon comes from the actual production of the food. The studies specifically state that by moving away from red meat and dairy products, that one will make a much bigger difference than simply buying locally.
As I drove past the big agriculture field in Ventura between Main st. and Seaward I was thinking about how even vegetarians are dependent on cows, (and their methane), for fertilizer. Just think about the way that it smells at Trader Joe's parking lot.
I'm not certain, but I'm fairly confident that "organic" doesn't necessitate absence of cow manure. Maybe a new category is coming, imagine little stickers on tomatoes at the store that say "no cow manure used." Or, better yet, "no shit." That would be hilarious.