"..An important albeit often overlooked personal choice of substantial GHG emission consequences is one’s diet. Evaluating the implications of dietary choices to one’s planetary footprint (narrowly defined here as total personal GHG emissions) and comparing those implications to the ones associated with personal transportation choices are the purposes of the current paper."
"In 2003, U.S. methane emissions from agriculture totaled 182.8 × 106 tonne CO2-eq, of which 172.2 × 106 tonne CO2-eq are directly due to livestock (U.S. Department of Energy 2004b). With 291 million Americans in 2003, this amounts to 800 kg CO2-eq per capita annually in excess of the emissions associated with a vegan diet."
"Meat production requires 6 to 17 times as much land as soy. (Reijnders and Soret, 2003)"
"The available evidence suggests that plant-based diets are safe, and are probably nutritionally superior to mixed diets deriving a large fraction of their calories from animals."
Animal-based burden is 1500kg CO2-eq per person per year, or 4.1kg per day! Three meals a day, makes this 1.37kg per meal. We serve about 150 meals per week. 150 x 1.37kg = 205kg per week or 10,000 tonness of CO2-eq per year!!
The average footprint for a person in the UK was 8.5 tonnes and in the US was 17.5 tonnes in 2008, so we have cancelled out the carbon footprint of 1176 UK and 571 US residents!
(We haven't taken into account the reduction of CO2 through cooking en-masse as opposed to people staying at home and cooking for themselves, but we recon that is cancelled out by the transport to get to us.)