¶Survivorship Earth. There are numerous ways that Earth could have become uninhabitable over the last 4 billion years. The Sun’s luminosity increased 30% over that time, requiring balancing forces to prevent the planet from overheating. Meanwhile, volcanoes, meteors, or both too much or too little CO2 all also could have easily rendered life extinct. Conventionally, it is assumed that feedback loops tend to stabilize these forces, but a recent paper suggests that luck also plays an enormous role. In simulations of 100,000 initially-habitable planets, only ~9% remained habitable in at least one simulation over a 3 billion year window, and only 1 out of the 100,000 remained habitable through 100 simulations. Survivorship bias likely plays a large role in how we view the Universe. | 
