Either Earth will eventually evaporate or it will be subjected to a period of unbearable heat followed by an eon of extreme cold. The forecast will hinge on the sun's ultimate distance from Earth. This distance will depend on how much mass the sun loses as it swells during the expansion or red giant phase. One possibility is that the sun puffs up so much that it almost reaches Earth. Heat from this swelled star scorches our planet's atmosphere, vaporizes vegetation, and boils away its oceans.
Earth looks like a wasteland.
Because there is no atmosphere, the sky is black. The sun is a huge, red orb that covers half the sky. Daylight is 3,000 times more intense than it is now. The intense heat eventually evaporates Earth. Another theory is that the bloated sun winds up far enough away from Earth that it does not burn off the atmosphere.