In 100 years, humans may live in underwater spheres and subterranean skyscrapers

Thanks to an expanding population, Earth-dwellers will need to find new and creative places to live. By 2116, the report proposes that humans will have underwater cities: “With advances in the efficiency of solar cells, it is likely that this free energy source will be used to create sub-aquatic communities, breathing the oxygen they create and fueling their electrical needs through the act of hydrogen creation below the waves.” Not everyone with a view of the sea will be below the waves, though. Floating cities will move all over the world to avoid harsh climates. Future generations will also live in earth-scrapers — essentially skyscrapers in reverse, burrowing deep into the ground rather than towering in the clouds.