There are a number of problems generated by population growth -- the using up of land is one that can be controlled by getting most people to live as Asians live in apartment complexes (quite luxurious). The problem of food has been a false problem for a long time, as technology has steadily improved diets in spite of the increasing population. Get people to stop eating meat as a main course and only as a condiment and the problem is cut in half (along with about a third of the global warming problem).
My point is not that population can grow indefinitely, but that it isn't a problem now and doesn't appear to be becoming one (with improving living standards family sizes naturally drop, and we've seen this literally everywhere). Modern projects say the earth's population should level off in about 50 years.