Humans eat a stunning amount of meat every year — some 800 billion pounds of it, enough flesh to fill roughly 28 million dump trucks. Our carnivorous cravings, particularly in industrialized, beef-guzzling countries like the United States, are one reason the planet is warming as fast as it is. Raising animals consumes a lot of land that could otherwise soak up carbon. Cows, sheep, and goats spew heat-trapping methane. And to grow the corn, soy, and other plants that those animals eat, farmers spray fertilizer that emits nitrous oxide, another potent planet-warming gas.
For all those reasons, and many more, activists and scientists have called for people to eat less meat or abstain altogether. At last year’s United Nations climate conference in Egypt, activists chanted slogans like “Let’s be vegan, let’s be free.” At this year’s conference, which starts November 30, world leaders are expected to talk about ways to shift diets toward plant-based foods as a way to lower animal agriculture’s climate pollution, the source of 15 percent of the planet’s greenhouse gas emissions.