believes that world will end before they die and have started preparing for it to survive.
If the world comes to an end then, by definition, there will be no survivors. We (USA) have a lot of nutcases mostly religious fanatics who believe the world is coming to an end -- it will but not for another few billion years.
It's the people who believe the world is coming to an end and decide to help the process along that worry me. It also bothers me that the end of the world (a least this week's version) is one day before my birthday. That blows. I guess I'll just have to start celebrating today.