Hawking warned you

Space.com has an article by Mike Wall, Space.com Senior Writer, about the future:

Stephen Hawking (photo) warned that humanity may have less than six hundred years to leave Earth.

Earth may be uninhabitable just a few centuries from now, so humanity should prepare to spread out into the cosmos, Stephen Hawking has advised.
If humanity doesn't become a truly spacefaring species in the next five centuries or so, we may well go extinct, Stephen Hawking said, according to media reports.
During a video presentation on 5 November at the Tencent Web Summit in Beijing, China, the famed cosmologist warned that the ever-rising human population, and its mounting energy needs, could render Earth uninhabitable by the year 2600, according to the British newspaper The Sun.
Hawking therefore advised that we get our act together and "boldly go where no one has gone before," The Sun reported.

Rico says, okay, so that's a line from Star Trek; the guy's a scientist, not a writer...