These natural events are rare enough that, to me, they don't create a sense of urgency that we need to get off the planet in the next decade.

This is the big question to me... when is the right time to go? If we wait 50 years, wouldn't the technological progress make such an endeavor cheaper, safer?

And the counterpoint is, well... it's been 50 years since apollo and still we don't have the ability to get to mars, so if there's nothing driving the technology then it doesn't just magically happen, and there's nothing to say that it will magically happen in another fifty years either.

To me, it's not the natural extinction events that are driving this, but the thinking that there is a short window of perhaps 200 years between technological enlightenment (particularly in nuclear and biological engineering) where the risk of self-annihilition is considerably increased, and the only way to decrease it is to add the redundancy.

To be sure, we will not achieve redundancy during the first decades or even perhaps centuries of this colonization. I think that terraforming needs to happen first