Apocalypses come and go. In the human times, there has not been one singular event that wiped out a large majority of the population. There have been "local" ca

Apocalypses come and go. In the human times, there has not been one singular event that wiped out a large majority of the population. There have been "local" catastrophes confined to a country or a region which have caused upheaval and changes of who is in charge. They're generally referred to as wars or revolutions. The things these folks are afraid of will mostly not directly be a danger to them. Massive amounts of money can directly protect you from epidemics, rising sea levels, inadequate food and water, and even nuclear war. Unfortunately, such events, and others, cause social unrest, which can devolve into chaos and war. This is what they are trying to protect against. It's not rising sea levels per se. It's pissed off and confused people searching for food and water and trying to enact revenge. There are many strategies for dealing with this. Isolation is one. Pre-emptive cooperation and guild-building is another. Doing whatever you can to keep the social system stable and mitigating reason for collapse seems like a good option as well.