Estimation of Carbon on Earth

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News: Deep Carbon Observatory (DCO) has released a series of papers estimating the total carbon on Earth


  • Two-tenths of 1% of Earth’s total carbon – about 43,500 gigatonnes (Gt) is above surface in the oceans, on land, and in the atmosphere. The rest is subsurface, including the crust, mantle and core — an estimated 1.85 billion Gt in all.
  • CO2 out-gassed to the atmosphere and oceans from volcanoes and other magmatically active regions is estimated at 280 to 360 million tonnes per year. This includes the CO2 contribution from active volcanic vents, from the diffuse, widespread release of CO2 through soils, faults, and fractures in volcanic regions, volcanic lakes, and from the mid-ocean ridge system.
  • About 400 of the 1500 volcanoes active since the last Ice Age 11,700 years ago are venting CO2 today. 22 ancient volcanoes that have not erupted since Pleistocene epoch (2.5 million years ago to the Ice Age) are outgassing.
  • Humanity’s annual carbon emissions through the burning of fossil fuels and forests, etc., are 40 to 100 times greater than all volcanic emissions.

Additional Information:

Deep Carbon Observatory (DCO):

  • It is a 10 year long global research program at the US National Academy of Sciences. It seeks to study the quantities, movements, forms, and origins of carbon in Earth.