21 March 2017, Rome--- Carbon is sequestered underground after being “fixed” from the atmosphere via plants or organic residues and then incorporated into soils through largely natural processes. Soil carbon content consists of both living and dead components, and can include both field stubble, as well as decayed materials from millennia ago. Already, one-third of the planet’s soils are degraded, leading to an enormous decrease in global soil organic carbon stocks and the release of up to 100 gigatonnes into the atmosphere. This week’s Global Symposium on Soil Organic Carbon is bringing together the science, policy and land-use community to build momentum behind preserving soil organic carbon and re-carbonizing degraded soils.