Generalization. Would be interesting discussion with details. Pop is growing. What's your concern - global warming, fertility rates, pollution, nuclear arsenal, running out of resources? Doesn't seem like we are doing that badly and that pop can't drop if get below renewable resource level or adjust to new ways of making energy/food, etc.
Does seem likely that on an extremely long time scale, we need to get multi-planetary, which is "realistic" if we give a reasonable time frame of, say, 10,000 years.
As far as the sun dying, that's beyond even parent point's timeline. This is very things start to get questionable if we never get to even .1 of c (e.g. Project Orion "realistic" estimates). Alpha Centauri is relative close at 4.something ly, but other "potentially habitable/useful" star systems are way out there.
Does seem likely that on an extremely long time scale, we need to get multi-planetary, which is "realistic" if we give a reasonable time frame of, say, 10,000 years.
As far as the sun dying, that's beyond even parent point's timeline. This is very things start to get questionable if we never get to even .1 of c (e.g. Project Orion "realistic" estimates). Alpha Centauri is relative close at 4.something ly, but other "potentially habitable/useful" star systems are way out there.