@ Jae: well, okay your majesty.
@ Totenkopf: Now dammit, I want your sentiment on this issue, after all it's the end of the world we're talking about here.
@ thread: There are so many one word things to reason for that which could destroy us. Stupidity, ignorance, greed, etc. I could not catalogue them all if I even cared enough to want to.
It's a hard sell but it's a tossup between:
WAR: Cold and/or hot, with or without weapons of mass destruction. However, such things are crude compared to the level of destruction caused by mass ignorance over time it seems. Or could I be wrong?
Disease: naturally occurring, man made in a lab, or man caused as a result of socioeconomic caste claiming the underclasses.
Natural disasters: Pretty much self-explanatory and somewhat covered above in diseases, but here puts emphasis to catastrophic geographic activity, weather that threatens to wipe the human race from the face of the planet, volcanoes, etc.
Technology: While I'm not sure if we have approached the age of Isaac Asimov's novels (reiterated through Terminator, mega man, I robot, etc.) I can see how we could do ourselves in by outsmarting ourselves. While I do not foresee that Commander Sigma is about to commit mass genocide or that t-101 in a mass army is going to hunt for John Connor, I do see a computer somewhere deciding that humans are inferior at one point and thus should be eliminated...and acting upon that because it is in charge of critical things. If it isn't already happening slowly.
Astronomic turbulence and activity:...hasn't claimed us yet, but you never know. Aren't we due for planet Nebaroo to come near our planet and throw our orbit off?
Which one of these do I think is most likely? They all seem roughly as likely as one another which is the scary part. I suspect that so long as it's a stalemate like it is, statistically it'll all remain as it is. This is already happening. And if one came down, everything else might just as well happen, too. I can't tell which one it'll be.