10. Plate tectonics keep the Earth comfortable.
Earth is the only planet in the solar system with plate tectonics. The outer crust of the Earth is broken up into regions known as tectonic plates. There are seven or eight major plates (depending on the criteria) and many minor plates. These are floating on top of the magma interior of the Earth and can move against one another. When two plates collide, one plate will go underneath the other, and where they pull apart, they will allow a fresh crust to form. This process is vital for a variety of reasons.
Not only does it lead to geological activity such as earthquakes, mountain-building, and oceanic trench formation, but it also is intrinsic to the carbon cycle. When microscopic plants in the ocean die, they fall to the bottom of the sea. Over long periods, the remnants of this life, rich in carbon, are carried back to the Earth’s interior and recycled. That pulls carbon out of the atmosphere, ensuring that we do not suffer a runaway greenhouse effect. Without the actions of plate tectonics, there would be no way to recycle this carbon, and the Earth would become an overheated place.