Your post didn't include any references to peer reviewed research papers, and you expect anyone to believe you over the article , which did? The full text of the research paper is also available The supplementary information (which as also linked to in the article, and is listed on the pnas page) has a whole lot of statistics listed, if you think the numbers given in the article are wrong, then do the math yourself. Here's another published peer reviewed research paper: Dietary greenhouse gas emissions of meat-eaters, fish-eaters, vegetarians and vegans in the UK (full text is available, not just the abstract) Study shows that meat eating people contribute to global warming about 50% more than vegetarians, and about twice as much as vegans. It also gives environmental impact ratings for different foods, (unfortunately by kilogram rather than by calorie, so could be misleading) Bovine Meat: 68.8, Mutton & Goat Meat: 64.2, Pigmeat:7.9 Crustaceans: 5.4, Fish, Seafood: 5.4, Poultry Meat: 5.4, Eggs: 4.9 So you can make a big difference just by limiting meat consumption to pork, seafood and poultry.
Animals only provide about 3% of the calories needed to raise them, which are in turn usually provided by corn feed. Directly eating the crops is much better, around 30% efficient http://www.imeche.org/docs/default-source/reports/Global_Food_Report.pdf
HAH. http://www.reddit.com/r/vegan/comments/2agot7/large_oxford_study_the_average_meateater_in_the/civ41md That sensationalist headline is total bullshit. The person's diet contributes twice as much. It says nothing about the contributions to global warming in general. Yes, meat takes more to make, and makes more emissions. No, it is not nearly as significant as the bullshit articles floating around.Study shows that meat eating people contribute to global warming about 50% more than vegetarians, and about twice as much as vegans.
I guess it's like if a study came out and said that drivers of Hummers contribute to global warming 50% more than drivers of Priuses, and 200% more than drivers of Leafs. When considering the footprint of the automobile specifically, that may be correct, but that isn't taking into consideration all the other life style choices which in aggregate, contribute more to a person's overall carbon footprint. Still a 50% reduction in the carbon footprint of your diet is still admirable and a positive thing, I'd say. To me, the bigger issue is that as a consumer, its hard to determine what the carbon footprint of various consumer choices are. It seems like a lot of red tape to require product labeling for carbon footprints like we do for nutrition, but as someone who is concerned about global warming, I'd like the ability to make choices on the consumer level without having to rely on marketers and relatively obscure academic research.