I didn't call it our back-up planet, I called it Elon's back up planet. Humanity will survive climate change. Our society may not, and that's what people try t

I didn't call it our back-up planet, I called it Elon's back up planet. Humanity will survive climate change. Our society may not, and that's what people try to insure against with bunkers or space colonies. To achieve that goal, the bunker or colony only has to be stable for a couple decades, maybe a century if you include the wish for a better life for their children.