Well, unless we blow ourselves up, pollute our planet to death or get smacked in the face by an asteroid first, according to scientists our sun is due to die in - I think - a couple of million or so years. So when our sun goes, we go. Unless of course we have the technology to move the planet or create our own artifical sun.
Either way, I think the human race might well be extinct by then anyway. At the end of the day, in life, there is always a cycle that repeats time and time again - birth - life - death.