Birth control? Really?
No. We have war for that now, and we still have disease. And even if you lump birth control in with it (as well as crime, disasters and alcohol-induced stunts), there's still a gross over-population of humans on this planet. I've said many times that we need less people, and while war is effective, it essentially weeds the strong from the weak by killing the strong. It's also far too specific in that it mostly kills people of one type, much like genocide. At best, population control should be enacted by something that doesn't care if your male or female, what race or religion you are, etc. Like disease.
Now, I'm not saying that I want smallpox, or that I want it to be unleashed onto the population at large, but that's only when I think about things in a personal manner. When looking at the big picture (like we should be doing here, as in "does the extinction of the tiger really have an impact on the world?"), it becomes clear that there are too many of us, and the eventuality is that one way or another, equilibrium will be achieved, and most likely that will culminate in some sort of mass culling of the human herd. (Cross your fingers for zombies.)