Look at two numbers: Square km of non-desert wilderness vs human agriculture. Mass of all domestic animals vs mass of wild animals. Gives a sense of the prob

Look at two numbers: Square km of non-desert wilderness vs human agriculture. Mass of all domestic animals vs mass of wild animals. Gives a sense of the problem. Or, the complete disruption of ocean ecosystems by over fishing, killing of top predators, fertilizer runoff, and so on.