Terraforming Mars, or maybe just create a habitable satellite is easier than saving the earth. Current economical model fosters growing business, and only government regulation to deal with externality. Growing is intuitive to human activity, but restricting human growth is counter-intuitive.

I forget the link, but a lecture video using bacteria growth as a metaphor of human growth creeps me out. Supposed bacteria in a jar growth 2 times for 1 minutes, and the jar will be full in 1 hour. When will the jar be half full? Answer is at 59 minutes. At the time of 58 minutes, only 25% space is used. How many bacteria thinks the jar or the world will be full after 2 minutes?

The situation is similar to human, and we still cannot find a way to protect the environment and have economic growth at the same time. Maybe the end of human history is next 2 years but we still think its pretty okay and didn't notice anything unusual. Then maybe finding a new jar is the second best way to deal with it.