For typical cataclysms, Earth is still a hell of lot more survivable than anywhere on Mars.
But for a really big one, the only solution is to be somewhere else when it happens.
A Mars colony is a first step.
But for a really big one, the only solution is to be somewhere else when it happens.
A Mars colony is a first step.
These might give you a hand if any single of the settlements (including Earth) get into trouble. This could range from preventing the disaster in the first place (nearby ship deflecting a potential impactor) to helping the survivors (medical supplies being dropped from orbit, habitat with failing life support being evacuated).
Self sustaining off-Earth settlements go way beyond just "oops, Earth is gone, at least someone is still left".