Recently many concerned eaters, worried about the number of "food miles" their meals have to travel between farm and fork, have sought to eat as locally as possible. While there are many fine reasons for doing so, the transportation of food turns out to account for only 11 percent of its greenhouse-gas emissions. According to Christopher Weber and H. Scott Matthews of Carnegie Mellon University, food production is a much greater factor-especially that of red meat, because of the high energy and fertilizer use required. Switching from beef to veggies one day a week, the researchers figure, would reduce your carbon footprint more than if you bought all of your food locally. The graph below measures various foods by metric tons of carbon dioxide equivalent per household annually. Non-CO_2 gases include methane, which cows burp, and nitrous oxide, released in the growing of cattle feed.
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机译：最近，许多担心的食客，担心他们的饭菜必须在农场和叉子之间穿行，才能达到“食物英里”的数量，他们寻求尽可能在当地就餐。尽管这样做有很多很好的理由，但食物的运输却只占其温室气体排放量的11％。卡内基梅隆大学的Christopher Weber和H. Scott Matthews认为，由于需要大量的能源和肥料，粮食生产是一个更大的因素，特别是红肉的生产。研究人员认为，每周有一天从牛肉换成蔬菜，比起您在当地购买所有食物，减少的碳足迹更多。下图通过每户每年二氧化碳当量吨衡量各种食品。非CO_2气体包括奶牛打的甲烷和在牛饲料生长过程中释放的一氧化二氮。
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