Overpopulation

It's the elephant in the room that no one wants to discuss, and for good reason. Addressing the problem of overpopulation cuts across just about every taboo in first world society: eugenics, religion, birth control, individual freedoms, inherent rights, etc.

I will posit this, however; we will be unable to address any of the major issues facing the world (starvation, lack of potable water, wars, habitat loss, greenhouse warming, etc.) if world population growth does not level off.