Regardless of theology, the cosmos is entirely volatile. If God does not exist (I believe God exists) eventually our Sun will die or go Supernova. At that point, Earth will cease to support life as we know it. Migration to another planet may be possible before that, but the planet Earth will, as you say, "end." I personally believe Jesus will return prior to that, or potentially simultaneously with that or immediately after that.
God won't destroy the earth if that's what you mean. He uses rainbows as a reminder of the promise he made to never destroy the earth after the great flood (genesis 9:13) And meek ones will posses the earth forever :) (psalms 37:11)