Honestly I'm not really sure how much population we can provide for - The truth is 80% of the world's wealth is concentrated in most of the developed world. Underdeveloped countries need a system to boost up the economy. I'm not saying we don't have an excess, but it's not as serious as people make of it. Arguably, the only governments with power to control people's bedrooms (technology, money, etc.) are the ones with less problems of overpopulation.
Whoever fights monsters should see to it that in the process he does not become a monster. And if you gaze long enough into an abyss, the abyss will gaze back into you