[PapaBear3625]

I do think that mankind can, and should, eventually spread to other planets. The sun brightens over time, and in 500 million to a billion years, Earth will be too hot no matter what Al Gore or anyone else says or does.

If in a million years we're not in a position to move the Earth to a different orbit, then perhaps we don't deserve to survive.

[RockinRight]

Good point...however I tend to believe that even if we can (physcially) move a planet like Earth, the chaos that would be caused might throw other planets out of orbit and potentially pull Earth right back where it was.

Furthermore, when Earth’s volcanic and plate tectonic activity stops due to the mantle cooling off (a couple billion years from now) that could pose another problem.

Not that any of us will be around to see it...