Volcanoes and the evolution of Earth's climate.

Volcanic activity has played a major geological and environmental role in the evolution of the Earth since the planet’s formation. As the proto-planetary Earth cooled and formed a solid crust, widespread volcanic activity dominated its surface. The Earth’s interior at this time retained a considerable amount of heat from accretion and the decay of short-lived radioactive isotopes. With interior temperatures well above the melting point of most Earth materials, high-density metals sank to the Earth’s center of gravity, while lower-density, silicate-rich materials were displaced toward the surface. It is believed that this process took place within the first 50 million years of Earth history, resulting in the present crust-mantle-core structure.