There are plenty of papers and meta papers that show that plant-based diets have a much, much lower impact on our environment than non-plant-based diets. And you have to remember that cows eat more plants than you do, therefore eating cows ends up using more plants, on top of the environmental impact of the animal itself.
There are also papers that already show that as far as personal lifestyle changes go, going vegan is the best thing you can do for the environment, for the average person.