The long view
James Lovelock, famous for his Gaia hypothesis, has pointed out how life evolved to cope with the slow heating-up of the Sun as it ages. Basically, Gaia juggles the CO2 content to maintain room temperature, and last time round that was achieved by evolving grass (no, not that kind of grass). But the game is approaching its end as CO2 levels have been driven down and down over geological time.
It is vital that we reverse our man-made CO2 excesses well below prehistoric levels, before the Sun heats up so much that even grass cannot push it back down far enough. Even borrowing genes from bacteria that live in boiling water, or improving the heatsinks on the CPUs that maintain us as cyber minds, can only buy us a little time. After that, the only way to stay cool will be to nudge our orbit further from the Sun, apparently rather faster than is happening naturally. Always assuming an advanced civilization is still left to do so. And after that, the problem will be how to stay warm after the Sun has collapsed back down again.
Space colonies, anyone?