Earth is the only planet with tectonic plates. Earth possesses water, the universal solvent and indispensable for life. Earth's mountains occur in chains. The giant mountains are Mars were created by volcanos. There is no equivalent to the Rockies, the Andes, the Himalyas, or the score of linear mountain chains. The process, the movement of planetary crust across the surface of the planet, is found in our solar system only on Earth.

Tectonic plates provide a wide range of biodiversity. The defense against mass extinction is diversity. Second, the tectonic plates provide our global thermostat by recycling chemical crucial to keeping the volume of carbon dioxide in our atmosphere relatively uniform. Third, plate tectonics is the dominate force that cause changes in sea levels, which in turn, are vital to the formation of minerals that keep the level of global carbon dioxide in check. Fourth, plate tectonics create continents on the earth. And finally, plate tectonics make possible the earth's magnetic field, the protection against cosmic radiation.

All the continents are masses of relatively low-density rock embedded in ground mass of more dense material. The low density rock have the average composition of granites, whereas, the higher density rocks that make up the ocean crust are basaltic in composition. Because granite is less dense than basalt, the granite rich continents float on a thin bed of basalt. The earth inner core is radioactive and generates heat deep inside the earth. As this heat rise toward the surface, it creates gigantic cells of hot, liquid rock in the mantle. The mantle rises, moves parallel with the surface for great distance, and then, cooled, settles back down into the depths. The upper mantle has a convection behavior. The mantle convects in the manner of liquid because the movement is so slow, and the temperatures so high, that the individual crystals have time to deform in response to stress.

Volcanos occur along subduction zones. The total are of the oceanic plates have decreased over time and the area of the continental plates has grown. The ocean crust can sink and be remelted back to magma. Whereas, the lighter continental crust remains afloat like a cork on the sea.

Plate tectonics promote environmental complexity and thus increase biodiversity. "Changes in continental position would affect ocean currents, temperature, seasonal rainfall patterns and fluctuations, the distribution of nutrients, and patterns of biological productivity." 2/3 of all animal species live on land. There are between 3 and 30 million plant and animal species alive today.

Volcanos recycle CO2 into the atmosphere. CO2 is stored in Limestone at the bottom of the ocean. The Limestone moves into subduction channels and is recycle through volcanic activity into the atmosphere. A temperature of 4-40 C is suitable for life and must be maintained. Greenhouse gases include: H20, O3, CO2, CH4 and are capable of capturing infrared energy from the earth's surface, in so doing, warm the planet. Oxygen and Nitrogen do not capture energy. However, suppose the oceans froze, this would cause an insufficient amount of CO2 generated for life to exist. CO2 constitutes on 0.035% of the atmosphere. Plate tectonics play an important role in maintaining levels of greenhouse gases. The water on the earth is .05% by weight. The maintenance of liquid water is controlled by global temperatures. The temperature of the earth is controlled by the amount of energy coming from the sun and how much energy is absorbed by the planet and how fast the greenhouse gases are replenished. If the green house gases are not replenished the earth will grow colder. "On a planet with volcanism there is usually an abundance of greenhouse gases, too much in some cases" - from both active and dormant volcanos.