I read a study that calculated CO2 produced/kcal eaten ... and if someone burned 1000 extra kcal/day ... and ate more food to replace those kcals ... it wasn't super green compared to efficient public transport

I do like to bike though

edit: crap summary is here: http://timeforchange.org/eat-less-me...ission-of-food

essentially 1 kg of meat is roughly 6L (1.5 gals of fuel burned).

it is interesting to think that way, however, I know you state that you're vegan.