I think that, before colonizing other planets, we should start by realizing that Earth can easily sustain human kind for the foreseeable future, given some pretty modest tweaks to our way of life (compared to "going multi-planetary" that is). If we start valuing quality over novelty, stop eating animal-based foods and re-organize to live closer to where we work, we can stop the consumption and that is taxing our ecos…
You're creating a false choice here. There's no reason we can't colonize other planets and also change local lifestyles. They're totally separate issues. Even if we treated the earth perfectly there's all sort of natural ways the planet could do us in or set civilization back a huge degree (asteroids, super volcanoes, etc.). Colonizing planets makes sense for the exact same reason insurance makes sense - shit happens…
https://www.theguardian.com/environment/2016/nov/22/nasa-ear...
all I am saying is that we need to keep our priorities straight.