Despite the linkbait headline, this is a decent article anyway:

Rowan Jacobsen in Outside:

Brown’s aha moment came in 2009, when the Worldwatch Institute published “Livestock and Climate Change,” which carefully assessed the full contribution to greenhouse-gas emissions (GHGs) of the world’s cattle, buffalo, sheep, goats, camels, horses, pigs, and poultry. An earlier report by the United Nations Food and Agriculture Organization had pegged that contribution at 18 percent, worse than cars and trucks. That’s shocking enough, but the Worldwatch study’s authors, two analysts from the World Bank, found that the FAO hadn’t taken into account the CO2 breathed out by our 22 billion livestock animals, the forests being felled to make room for pasture and feed crops, or the total impact of the 103 million tons of methane belched into the air by ruminants each year. When everything was tallied up, Worldwatch estimated, livestock were on the hook for 51 percent of GHGs.

That was all Brown needed to hear to put the plant-based McDonald’s back at the top of his agenda. Forget fuel cells. Forget Priuses. If he could topple Meatworld, he thought, he could stop climate change cold.