A new report from Worldwatch Institute suggests that up to 51% of annual worldwide GHG emissions are attributable to meat (cows, pigs, chickens, etc) grown for food. Previous estimates from FAO suggested the figure was 18%. Some of the conclusions of the new study will certainly be questioned. For example, the study includes animal respiration (breathing) in its calculations. You can read it yourself (pdf available here). But either way, there is no question that meat production is a huge source of emissions, responsible for more GHGs than transport (driving cars).
So, does this mean that you can't really claim to be an "environmentalist" if you eat meat?
Hat tip: env-econ