The world is going to end. Or not. Either way, how do we know? Is it time to prepare our last supper?

We've looked to the only people who know about this stuff -- filmmakers, of course, to see what scenarios tell us the world is in-fact ending. 

#1. The sudden, and unwelcomed, addition of Aliens on our Earth. Independence Day, anyone?

#2. A massive asteroid, large enough to take the term the big bang theory to a whole other level, is headed for our planet. Queue Aerosmith's, I don't Want to Miss a Thing.

#3. If women have been infertile for decades, then it's fairly certain that at some point, our species will become extinct. [Enter] Children of Men.

#4. If there has been a horrible endemic creating an entire country to be overrun by zombies and the only living humans left (on said country) are cannibals. If this should happen, fear of a deadly pandemic 28 Days Later is understandable. 

#5. If, rapidly, various countries begin to experience natural disasters. If the ice caps begin to melt, and temperatures change across the globe, then, and only then can we wonder. Hmmm? Wait. Japan; Haiti; Spain; polar bears . . .