In a few billion years, there will be no doubt about the reality of climate change or the culprit thereof: The sun will have started expanding and heating up. Sometime between 1,000,002,017 and 2,000,002,017, the Earth's mean surface temperature will be hot enough to boil water, because the sun's energy output will have increased over that time.
This is before the sun expands in a planetary nebula and pretty much cooks the planet to a cinder.
Ethan Siegel, writing at Forbes' "Starts With a Bang" science blog, considers a reader question about a way to deal with the problem. Could we move the planet out of the neighborhood, to the point where all of our water wouldn't turn into Bernie Sanders/Donald Trump exhalations and leave us with the frightening possibility that Chris Christie could decide our baked lawn was his new favorite sunning spot?
Shuffling off to a new orbit would have the advantage of requiring little maintenance, Siegel points out. Once we've moved, we've moved. Space- or atmosphere-based solutions that would reflect more of the sun's energy and keep us cooler would need to be kept up, and one failure could be catastrophic. Terraforming Mars would also require a lot of care and attention, since the same things that caused the Red Planet to lose its atmosphere and water a few billion years ago are still present. Mars is too small to hold a thick atmosphere without help.
On the other hand, as Siegel describes the engineering involved, moving something as big as a planet might be physically possible but practically impossible. Moving the Earth might cause more damage than the project was trying to prevent.
Of course, the likelihood is than in a billion years or so whatever critters we've turned into have probably become smart enough to be ready to bail off this rock when it gets unlivable. That us, unless evolutionary processes have failed to rid us of non-survival characteristics like the appendix and Congress. If we still have those we're doomed.