What is the importance of carbon on Earth?
Carbon is the chemical element that is the main building block of living organic matter.
It is essential in all biological processes and in a great variety of mineral and inorganic processes near the EarthÆs surface.
In the form of carbon dioxide, it is a greenhouse gas and its atmospheric concentration is demonstrably tied to climate.
Its recent growth in the atmosphere due to human activities is believed to be responsible for the enhanced greenhouse effect and global warming of the Earth.
The title of this book, Carbon in the Outer Shell of the Earth, conveys our view that the naturally occurring chemical compounds of carbon and, in particular, carbon dioxide always played an environmentally important role in the different parts of the Earth that comprise its outer shell, from the base of the lithosphere, -150 km below the surface, to an altitude of about +30 km. The outer shell includes the lower atmosphere, continental, subsurface, and oceanic waters, the biosphere, and the minerals in the sedimentary and crystalline lithosphere.
