The sun is 93 million miles from the earth and in our solar system it is the one thing that keeps the cycle of life and regeneration going on the earth. The Sun is ball of fire that has a million nuclear explosions going on that generate tremendous energy. The earth has as yet not tapped even 0.5% of the solar energy that emanates from the sun.
Having said this it must be understood that the sun is like a super nova and will ultimately burn itself out. However the consoling thought is, that this event is some billions years
Scientists are of the opinion that once the hydrogen energy starts to dry up the Sun will expand with a last gigantic explosion and the flames will rise to reach the earth and swallow it at one go. In other words the sun will become a massive ball of fire that will engulphed not only the earth, but all planets in the solar system.
However before this happens life on earth would cease to exist, as about 1 billion years from now all water on earth would evaporate due to the heat of the sun and life as we know it would be extinguished. Most likely man would have left earth a long time earlier. That is the law of nature.