Scientists Discover Gigantic Global Reserve of Soil Carbon Underground

Soil carbon typically refers to the organic component, termed soil organic carbon (SOC). However, there is also an inorganic component, referred to as soil inorganic carbon (SIC), which is often composed of substances like calcium carbonate. SIC commonly accumulates in arid, less fertile regions, which has led many to believe it is not important.

In a study published in Science, researchers led by Prof. Huang Yuanyuan from the Institute of Geographic Sciences and Natural Resources Research of the Chinese Academy of Sciences (CAS) and Prof. Zhang Ganlin from the Institute of Soil Science of CAS, together with collaborators, have quantified the global store of SIC, challenging this long-held view.

The researchers found a whopping 2,305 billion tons of carbon stored as SIC in the top two meters of soil worldwide, which is more than five times the carbon found in all of the world’s vegetation combined. This hidden pool of soil carbon could be key to understanding how carbon moves around the globe.