No need to look it up. I worked in ecology for a decent part of my career. In the U.S., for instance, far more land is cultivated for animal feed than for people food. It's true that industrial farming is not particularly eco-friendly at all. But meat requires both pasture land and mass farming. The amount of mass farming to support animal feed alone (from hog and chicken feed to "finishing" for beef) is much greater than the amount used for feeding people. It uses about 60% more acreage (127 million for animal feed vs 77 million for food we eat directly) - all with the same mass farming practices and per-acre ecological impacts. So by definition, the impact of eating vegetarian is much lower - because livestock requires greater per calorie "on the plate" farming impact - plus the clearing of pasture land, methane output, antibiotics, etc. On a calorie basis, farming and then feeding it to livestock to then feed to people is about 1/10th as efficient as farming and feeding it to people. I am not a vegetarian, but I am not a heavy meat eater for many reasons, this being one of them.