Just to compare: there's an estimation that there are around 300 000 gorillas in the entire world. There are over 20 000 humans for every gorilla.
Though I think that "environment" is too vague. Planet doesn't care. Some bacteria probably would think that it's pretty nice environment. It's more about human waste making environment bad for humans themselves.
There are just too many of us, so we need artificial ways to produce food, artificial ways to protect from cold and heat. And also artificial ways to safely dispose of our waste.