You are all thinking too small on the natural disasters. Here's one that nobody has mentioned. Global natural disaster. The more unlikely of the two (at least in my lifetime) is the planetary magnetic poles reversing. The geological record shows that this has happened several times in the past. Nobody knows the impact, but since we're looking for a worst case scenario, let's say it acts like a planet wide EMP.
Katie bar the door!
And of course, asteroid impact. If it is a dinosaur killer and you happen to be in the same hemisphere, it is probably not survivable, surely not long term. But the other hemisphere and the equatorial region should sustain life. Dinosaurs died out because of their mass. Plenty of life survived the mass extinction, it was all small. And those were animals who had no control over their environment. Man would fare better.
Katie bar the door!
And of course, asteroid impact. If it is a dinosaur killer and you happen to be in the same hemisphere, it is probably not survivable, surely not long term. But the other hemisphere and the equatorial region should sustain life. Dinosaurs died out because of their mass. Plenty of life survived the mass extinction, it was all small. And those were animals who had no control over their environment. Man would fare better.