Reducing the amount of meat you eat in a week can have a big Environmental impact. According to a study in the American Journal of Clinical Nutrition, the production of one calorie of animal protein requires more than ten times the fossil fuel input as a calorie of plant protein. In fact, more than 1/3 of all fossil fuels produced in the United States go toward animal agriculture. Animal farms are responsible for about half of our total water use, and animal waste causes water pollution that devastates ecosystems and poisons groundwater. Waste and chemicals from factory farms also cause air pollution and human health problems. The next time you order a hamburger, consider that with the energy needed to produce a single beef patty, you could drive a small car twenty miles. It should also be noted that 70% of former forests in the Amazon have been turned over for grazing, and that cows are one of the greatest emitters of methane, the second most significant greenhouse gas. Their grassy diet and multiple stomachs cause them to produce methane, which they exhale with every breath. Cutting out meat altogether will reduce your carbon output more than driving a Hybrid, but going veg isn’t for everyone. To make a difference, reduce the meat you eat by at least one meal a week, and try limiting your beef to special occasions.