I'm not worried about temperatures 170,000 years from now - it'll come on slow enough that they'll figure something out.
But, on a somewhat related topic, I believe we've long since used up all of the easily accessible oil and coal. So, if (when?) we end up wiping ourselves off the planet, the next round can't become a technologically advanced (?) society like ours using the same path that we did. Is there another path to high technology? Any historians out there know? If there isn't, then I guess we've made sure that if we go, Earth won't have another bunch like us. That's not a big loss, I expect, unless we happen to be the only advanced bunch there is anywhere.
Of course, I don't expect much sympathy for this view from the highly self-centered El Reg crowd.
The alien icon because maybe the next round won't be our descendants.