Simulation: Earth is out! Humans are the grey; water is Blue: Desert is Tan; Forests are dark green; Grass is light green. Forests grow if they are close enough to water, but not if they are near human settlements. water spreads randomly. Humans built settlements if they are close enough to either water or trees. Desert is created anywhere there is not water, human settlement, or forests. Around human settlements where there is no forests, grass will grow.
PLEASE USE TURBOWARP! THIS IS A NON INTERACTIVE SIMULATION!