[Ekaros]

Earth is so much better place to live that only scenario where I see us actually needing Mars or other off-planet habitation is something like moon sized object hitting earth or maybe rogue blackhole. That is total apocalyptic destruction of planetary body itself.

Mars sucks, and Earth will never be as bad. And anything we can use to live on Mars can be done on Earth, without the involved transportation costs. And self-sufficient colony is just pure sci-fi.