Cereals and carbohydrates had the smallest footprints, with each pound of food releasing only 3 lb of greenhouse gases and almost no nitrogen pollution.
谷物和碳水化合物的足迹最小，每磅食物只释放3磅温室气体，几乎没有氮污染。
2
noting that cows produce 13 to 30 lb. of carbon dioxide per pound of meat.