All that can be done in that regard is already done.
Hans Rosling summarizes so much better than I possibly could, in his Ted talk.

http://www.youtube.com/watch?feature=player_embedded&v=ezVk1ahRF78

The population explosion is over, the rising numbers are all inertia, and completely unavoidable.

As far as I know, only China successfully restricted population growth. When people have reasonable life expectancy and women get an education, the population restricts its own growth. Improving outcomes in these two respects, in countries which have not yet made the demographic transition, is the key to limiting population growth.

The situation is far from hopeless, because a lot of progress is going on.

_{It is rightly acknowledged that people of faith have no monopoly of virtue - Queen Elizabeth II}

this reminds me of the projections of nuclear power believers when they say we can never generate enough energy greenly to supply our future needs, while ignoring how wasteful our current practices are.

when this kind of doomy blackmailing is used it is always a linear extrapolation of an already flawed model, ie that all 7 billion of us will all be eating eggs and bacon for breakfast, a big steak and some cheese for lunch, and fish for dinner.

Ain't Gonna Happen... nor should it!

'The history of public debt is full of irony. It rarely follows our ideas of order and justice.' Thomas Piketty