Most people are frightened of the question and usually choose to ignore it, what happens when "the world ends" ,but maybe the answer is in the question itself. By "the end" I presume that you mean "the end of earth" or "the end of all existing life on earth". The only guaranteed way the earth will be a place uncampatable with human life is from the super nova of our star in about 4-5 billon years. By that time, if the human race hasn't completely killed itself off already, then we will have found many other planets compatable with human life, and if not we will be living on a space station far enough away we will survive.
