According to J. Richard Gott the Third
We have between 5,100 and 7.8 million years left for our species.
More here:
http://en.wikipedia.org/wiki/J._Richard_Gott
Space/Science » in reply to I think we have about a century and a half to go
We have between 5,100 and 7.8 million years left for our species.
More here:
http://en.wikipedia.org/wiki/J._Richard_Gott