In SimEarth: The Living Planet, you begin with a barren, lifeless world and guide it through billions of years of development. Every system—atmosphere, temperature, tectonics, oceans, landmasses, and biospheres—interacts dynamically. A shift in greenhouse gases can warm the planet; a change in ocean salinity can alter life’s trajectory; a tectonic adjustment can reshape continents. The simulation is alive, constantly evolving based on your decisions and the natural forces at play.