I'm thinking more in the 10-20 year range. But I really have no strong evidence to back it up. I don't think anyone can know for sure.
I never personally considered those possible disasters. If you're informed, its pretty obvious when something is just media buzz and the fad for paranoids to freak out over. I don't consider myself paranoid or afraid.
I just see something like we've been talking about as a real possibility. There are many signs.