So ya wanna save the world single handedly, do ya?

After much thinking, I've come to the conclusion that there are two ways to do this, and only two.  Before we start, let's think about the greatest global issues we face right now: war, famine, disease, global warming, and stupid people.

Here's how to get rid of the problem: Get rid of half of half the world's population.  Now wait, before you try to flame me to death, you need to hear the reasoning.  We can get rid of the overpopulation.  Wipe out the disease.  Drastically reduce pollution and everything related to it.  And there will finally be enough resources for everyone in the world.  It's survival of the fittest!  Keep the strong and intelligent, and weed out the weak.  It sounds crass, but that's the only way to fix the sad state that our world is in.  Of course, deciding who to lose and who to keep is a whole other can of worms....

Option two is to build teleportation devices.