[maxrecursion]

Western societies are already down to around replacement levels with some going below it. It's pretty clear cut as societies evolve that population growth evens out. It's 3rd world countries driving the population growth. Over-population of humans being a danger to the earth has been proven false time and time again.

[vacuity]

Overpopulation needs to be qualified with the context of the living standards. Ten billion vegetarians is probably feasible, but ten billion Americans (we don't currently have as many at such a standard) is a different story.