We will either be long gone as in extinct or long gone as in our distant
descendants will have populated the galaxy and beyond by then, so
that Earth will be some half-forgotten place of legend like in Isaac
Asimov's Foundation Series.

The problem is we keep limiting ourselves to one planet when there are
solutions and alternatives. As Carl Sagan once said, the occasional
impact from space is nature's way of telling an intelligent species to get
off its planet or else.

Same for the changes that will happen with Sol some day. It is pretty
obvious judging how the Universe acts with all these exploding stars,
nasty radiation, black holes, and colliding galaxies (and who knows what
the heck Dark Matter might do), that life is an accidental by-product of
existence that because some of it is vaguely aware thinks it is the whole
reason and ultimate goal for everything.

If nature has taught us anything in the little that we have learned of it
so far, especially in the mere bucket drop of time when we have finally
begun to get a grasp on how big and how brutal many cosmic things are,
is that we better spread ourselves out long before those celestial bodies
and events come a'calling and we're caught with our pants down, so to
speak.

And no more excuses. We either start colonizing or die. We won't be
able to catch all the potential impactors and I do not want to wait for
some very distant children to figure out a way to keep Sol in its yellow
dwarf state for a few more billion years.

And don't tell me a few others out there haven't had the exact same
thoughts and acted upon them. So we either get on the cosmic band
wagon or we go back to our reality shows and Big Macs and wait for
the inevitable to show up in all its horrible indifference. Because that
is what the Universe is - indifferent.