What it going to happen to earth?

Answer 1

In about 4 billion years time, the sun will become a red giant and become so large that its radius will swallow up orbits or Mercury and Venus, and possibly the earth. Long before then, the earth will have become too hot and dry for any life forms to survive. It is possible that an impact by a body from space - a meteor or comet - will cause significant damage before that. This could result in mass extinction or worse. But my expectation is that humankind will have destroyed life on the planet long before we get to that stage.