For as long as I can remember, which now is approaching sixty years--granting that before one year of age, memory for me is more a function of guess work and received wisdom than actual recall of events, although I have definite knowledge in the form of some kind of memory of events when I was just days old and certainly from two on--years that is. My short term memory is known to process directly into long term, and it's anyone's guess what that means--all that aside--for as long as I can remember certain of the town criers have been preaching apocalypse, the end days, with every war, 9.0 magnitude earthquake, land scrubbing tsunami, civilization burying volcanic eruption, and nuclear meltdown serving as further proof of the end of our time on this planet--perhaps even the end of life in the Universe, which is a little hard to credit. But who can say?
I prefer to think that when life ends, it is dispersed into the quantum gruel, maybe to be reconfigured, maybe not. Certainly reincarnation is a matter of faith at present, and I suspect well into the future. Saying that, puts me in the camp that believes life in the Universe is rare, and that, despite the lack of evidence to the contrary, is as an absurd assumption. I'm going to have to go with Heraclitus on this one and say that the Universe is in constant flux, a dance of destruction and construction. There's no one behind it---not even a phony wizard in this Oz. It is, and it follows its own rules which themselves are doubtless always in flux.
Tempting though it might be to look for an astroid or some cosmic lightning bolt that would purify the Earth, such an event is unlikely.We are far more likely to be hit by a succession of lesser--a relative term--catastrophes from which we ultimately cannot e scape. Their cumulative power is too great, and we are too weak or overextended. From a certain remove, of course, these take on the characteristics of a single event.
But they are not. They are constants in our lives.