[Johnny555]

If we can't live comfortably on earth (even with the worst expected effects from climate change), how can we live on another planet or in outer space which has a far less hospitable environment than any climate change could cause here on earth.

I think of space colonies as being protection from some catastrophic event on earth, not as an answer to climate change.

It's not like we could move significant numbers of people off the planet... and if we can build a spaceship or habitat on another planet that people can survive (and thrive) in, it would be much much easier to build the same habitat here on earth. I would bet that even building an underwater city would be much easier than a moon colony or orbiting space station.

[usrusr]

Yeah, I've had that thought often enough. If we can't make people enjoy living in (insert least popular region in your cultural environment), how would anybody want to live in space/the moon/on Mars?

These days it's flanked by a much darker counter: well at least space would provide a society that has reproduction under control with a reasonably wide moat from breeders.

[brippalcharrid]

It means creating such an abundance of technology that we will be able to supplant the limitations that we are currently operating under so that we can fundamentally alter our opportunities as a species.

Rather than spending the next few hundred years going round and round in ever-decreasing circles, obsessing over reducing the human impact on the planet to negligible levels using limited technological advances, while remaining largely inward-looking and ensconced within our gravity well.

I find that there's a weird mixture of pessimism (billions will die of starvation within 30 years) and hubris (we need to adopt measure X so that we can achieve Y degrees of warming by 2050, rather than Y+1 degrees) that has categorised the more prominent Malthusian technocrats over the last few decades (such as the Club of Rome, and then the IPCC).