Keep Your Options Open
Certainly a nuclear war, a worldwide fatal contagion, or a global zombie apocalypse would all be difficult trials to endure. An ice age might push civilisation to the very brink. But Earth abides, and humans could too. In the near future, the only catastrophe that might require the complete abandonment of the planet, would be an extraterrestrial strike -- a comet, asteroid, or equivalent large scale impact.
A missile silo home such as the one above provides the convenience of an onsite rocket launch pad, with the added convenience of an on site airfield.
Should a majour planetary catastrophe occur, one would certainly wish to have a convenient launch pad capable of carrying one's self and significant others. One would also need a destination in Earth orbit, where one could "freshen up" and restore one's natural sense of vigour and vitality.
A well equipped full-sized space station can make all the difference, should your home planet suddenly become uninhabitable.
But since humans are much more comfortable on planetary surfaces anyway, you would probably already be thinking about relocating to Luna or Mars. The sooner the better, so as to claim the best real estate and avoid the land rush.
To assist your planetary habitat-building, special robotic apparatuses are being developed which will allow you to construct your Lunar or Martian habitat over a 24 hour period, using a robotic contour crafting robot.
Parenthetically, similar robotic contour crafters could also be used to build an underground missile silo home & retreat on planet Earth, if you cannot find a suitable one available. International treaties are causing such valuable properties to become scarce.
Regardless, try to keep all of your options open. Most types of apocalypse will allow you to continue to reside on the most beautiful and life-loving planet in the solar system. But some types of doom will not permit that.
Hope for the best, prepare for the worst.
Adapted from an earlier posting on Al Fin Potpourri