Fossil carbon is carbon that was created and bound up in geological formations millions of years ago and is now being released into the atmosphere in the form of carbon dioxide. As our global energy and economic systems increasingly rely on burning the extracted hydrocarbons left over from the Age of Dinosaurs, ancient carbon normally bound up in gas, liquid, and solid form is released into the atmosphere where it contributes to the cumulative, global atmospheric carbon and warming effect.

See also: fossil fuel, fossil energy, fossil hydrocarbons, carbon pulse, climate change