The production of a typical pound of beef in the United States requires 2,500 gallons of water. When you cut back on your meat consumption, you help to save an immense quantity of water. While many cows live in feedlots where they are fattened up with grain and soybeans, some still graze in fields. Unfortunately, that's often not much better. Overgrazing is so common that it's considered normal.
Cows eat the bigger plants, and their hooves trample the smaller ones.
When many cows are on one piece of land, it usually ends up as a desert. The next step is to cut down forests to make up for the lost grazing land. And so it goes. Our forests keep on shrinking, and our deserts continue to expand. That's more than an acre for every US citizen.