Originally Posted by Eldorado
Not a few million. 1-3 billion. The earth will be uninhabitable somewhere in the gradual warming phase.
It says right there on the illustrationg "approx". Not all G type stars live exactly 14 billion years. Some can be shorter, say 10-12 billion years. There's no real way to say how much longer we have until the Sun starts heating up. It could be a few million, it could be a few billion. Better to estimate the lower side of things to be on the safe side.