Global Thermostat

As part of the surprising importance of plate tectonics for the sustaining of the conditions necessary for life, it appears to act as a global thermostat.

The Promotion of Diversity

The continental drift associated with plate tectonics changes the environment for the life forms. This is thought to have promoted the diversification of species, and that diversity is one of the strongest defenses against extinction.

The Effect of Sea Level Changes

The model of plate tectonics in its role as mountain and continent builder preserves the range of altitudes above the sea level. Without this role, the mountains would eventually erode down. It has been suggested that sea level changes can contribute to an effective global thermostat by exposing more carbonates at the sea's edge and contributing carbon dioxide to the atmosphere.

Continent Forming

Since the continents have provided the greatest diversity of life, it can be argued that the role of plate tectonics in building continents is a favorable one for life on the Earth.

The Conditions for a Planetary Magnetic Field

The basic structure of the Earth, aided by plate tectonics, makes possible the Earth's magnetic field. Neither Venus nor Mars has such a magnetic field. Venus has core and molten regions like the Earth, but a very slow rate of rotation. It produces neither plate tectonics or a magnetic field. Mars has volcanism, but limited to a small number of spectacularly large volcanoes like Olympus Mons. It's magnetic field is weak despite a rotation period similar to that of the Earth. This suggests that the molten nature of the Earth's mantle that facilitates plate tectonics is also essential for the operation of the dynamo that produces the magnetic field.

The Earth's magnetic field is a strong protective influence against bombardment by the high energy charged particles that we call cosmic rays. As such high speed particles approach the Earth, they are deflected by the magnetic force, which reduces the irradiation of the Earth's surface.