I remember a teacher said that the Sun is approx. only in its mid way of life and so there are still billions of years to go. I am not worried. From wild guess, I am pretty sure our Earth will be finished well earlier before that of the Sun. We are talking about global warming, water levels, food crisis ,wars and even the crush of outer space rocks etc.. .but all these things would not lead the death of the earth right? And in the worst case scenario, it will only lead to extinction of human? Am I correct?