Animal foods require immense quantities of petroleum to produce. For example, while it takes only two calories of fossil fuel to produce one calorie of protein from soybeans, and three calories for wheat and corn, it takes fifty-four calories of petroleum to produce one calorie of protein from beef! Animal agriculture contributes disproportionately to our consumption of petroleum and thus to air and water pollution, global warming, and the wars driven by conflict over dwindling petroleum reserves.