That kind of timescale often makes me wonder, how do we know there aren't millions of tiny black holes all throughout the planet slowly growing?
The Sun's dying and will become a red giant (about 5 billion years to go), but it's luminosity is currently increasing, so our rock will become a scorched Earth in around a billion years. Then there's the potential for meteors, climate-change, antibiotic resistance, or millions of tiny black holes to do us off first (how quickly do black holes grow, anyway?)
Colonising other planets and other solar systems seems the only viable solution to the long-term survival of the human race.
Or maybe they are the dark.