how many years do humans have left on earth
Update Date: Sep 20, 2013 04:33 PM EDT. Speculation has come and gone as to when the world will end, but now scientists have put a date to when Earth will become unable to host life. Rest assured though, that day will only come some 1.75 billion years from now. Researchers at the University of East Anglia in the United Kingdom have determined that Earth will become inhabitable in 1.75 billion to 3.25 billion years' time.