[ninjanomnom]

(I assume you meant uninhabitable)

For the individual the answer is almost certainly yes. If we have the ability to survive elsewhere than earth and we have brought earth to the point that it is 99% uninhabitable then going someone else is probably the best choice.

One could easily argue that our ability to consider our environment and make changes to our behavior accordingly is unnatural. Avoiding the above scenario is something we should be using our unnatural gifts to avoid.

Arguments based on how natural something is is highly subjective and not really worthwhile imo. Replace natural with what we're actually trying to discuss: As a species we want a stable environment that requires the least effort to survive in. Individuals have additional traits they want from the environment but that's all subjective. Things that most people consider natural are usually things that have a large data set to demonstrate their stability.

[imtringued]

>For the individual the answer is almost certainly yes

That type of thinking will ruin the second planet just as much.

[TeMPOraL]

Hence the root cause of all human-caused problems: what is locally, short-term beneficial for an individual is often long-term detrimental to the group, and long-term success of an individual depends on long-term success of the group.

I.e. we're too competitive, not cooperative enough, and can hardly coordinate at scale. Our best coordination mechanism we've ever came up with is the market economy, which is essentially taking the survival instinct of individuals and building a distributed coercion system with it. Sure, it works, but wouldn't it be nicer if we could just talk our way into working together on shared goals, instead of using money and threats of starvation?