Well, there is the question of whether we will ever have the possibility of developing this technology again. I see no immediate risks to life on Earth, and co

Well, there is the question of whether we will ever have the possibility of developing this technology again. I see no immediate risks to life on Earth, and considering we're quite hard to get rid of, I suspect the human race will be here for quite some time yet. The ability to do a large-scale settlement on other planetary bodies on the other hand, might go away considerably sooner, and who knows if/when we will be able to do it again if we ever end up in a situation where it might be needed. Regardless, there are other reasons, as you say. For one, space-based manufacturing would allow us to increase the standard of living on Earth without having to worry about things like CO2 levels and pollution. If we start commercializing space then I expect colonization to follow as a natural result of that and we won't have to worry about the more philosophical side.