Challenges for Human society. Future of Human society. Future of the Earth. 200 million years later : Formation of the supercontinent. 400 million years later : Extinction of the C4 plants. 1 billion years later : Cessation of plate tectonics. 1.5 billion years later : Disappearance of the ocean. 4.5 billion years later : Collision between the Milky Way Galaxy and the Andromeda Galaxy. 8 billion years later : Annihilation of the Earth. Humans will eventually create self-replicating robots and go out into space. As a result of the fact that the Earth has been cooling since its birth, the depletion of surface ocean water will stop plate tectonics and turn it into a Venus-like planet. Then, about 8 billion years later, the Earth will be swallowed by the expanding Sun. However, by that time, Earth’s life has already changed and will have reached other galaxies as self-replicating artificial life.