I’d be interested to hear whether you think eventually expanding beyond our solar system is necessary for achieving a long period with very low extinction risk (and, if so, your reasons for thinking that).
Context for this question (adapted from this comment):
As part of the discussion of “Effective size of the long-term future” during your recent 80k appearance, you and Rob discussed the barriers to and likelihood of various forms of space colonisation.
During that section, I got the impression that you were implicitly thinking that a stable, low-extinction-risk future would require some kind of expansion beyond our solar system. Though I don’t think you said that explicitly, so maybe I’m making a faulty inference? Perhaps what you actually had in mind was just that such expansion could be one way to get a stable, low-extinction-risk future, such that the likelihood of such expansion was one important question in determining whether we can get such a future, and a good question to start with?
I haven’t really thought about this before, but I think I’d guess that we could have a stable, low-extinction-risk future—for, let’s says, hundreds of millions of years—without expanding beyond our solar system. Such expansion could of course help, both because it creates “backups” and because there are certain astronomical extinction events that would by default happen eventually to Earth/our solar system. But it seems to me plausible that the right kind of improved technologies and institutions would allow us to reduce extinction risks to negligible levels just on Earth for hundreds of millions of years.
But I’ve never really directly thought about this question before, so I could definitely be wrong.
 I’m not saying it’d definitely help—there are ways it could be net negative. And I’m definitely not saying that trying to advance expansion beyond our solar system is an efficient way to reduce extinction risk.
Thanks Michael! I agree space colonization may not be strictly required for achieving a stable state of low x-risk, but because it’s the “canonical” vision of the stable low-risk future, I would feel significantly more uncertain if we were to rule out the possibility of expansion into space, and I would be inclined to be skeptical-by-default, particularly if we are picturing biological humans, because it seems like there are a large number of possible ways the environmental conditions needed for survival might be destroyed and it intuitively seems like “offense” would have an advantage over “defense” there. But I haven’t thought deeply about the technology that would be needed to preserve a state of low x-risk entirely on Earth and I’d expect my views would change a lot with only a few hours of thinking on this.