http://www.fao.org/docrep/010/a0701e/a0701e00.HTM http://www.fao.org/docrep/010/a0701e/a0701e00.HTM Here's an 18% estimate while transportation is 13%. Here's

http://www.fao.org/docrep/010/a0701e/a0701e00.HTM http://www.fao.org/docrep/010/a0701e/a0701e00.HTM Here's an 18% estimate while transportation is 13%. Here's a 51% estimate, trumping everything else. http://www.worldwatch.org/node/6294 http://www.worldwatch.org/node/6294 No one can say with certainty. Although, raising 100 billion animals yearly, most of them having over 250lbs, I'd say it's pretty close for CO2. When it comes to methane, cow farts are 65% of our methane emissions. http://www.fao.org/docrep/010/a0701e/a0701e00.htm http://www.fao.org/docrep/010/a0701e/a0701e00.htm