Universe Today has a post outlining the future end of everything.
But a species can last tens or even hundreds of millions of years. So how can we predict when our number will be up?
There’s no way to know, but there’s a calculation that can help. It’s called the Doomsday Argument, developed in 1983 by astrophysicist Brandon Carter. According to Carter, if you assume that half of the humans who will ever live have already been born, you get approximately 60 billion people. If you assume that another 60 billion are yet to be born, our high population levels only give us another 9,000 years or so. Or more precisely, there’s a 95% chance that humanity will have ended by the year 11,000.
And it continues going up to the end of light through to 10^100 years from now, at the end of the proton.