How can the human race survive the next hundred years?

There's more to the Mankind than we see. Mankind survived for more than 1.5 million years...It will go on more than another hundred.

That's a difficult question. The world today is a lot more complicated. With the advent of technology that can destroy mankind, all it takes is one rouge state to destroy the entire world. The only way we can sustain another 100 years is if you can find some kind of peace with all nations in the world.