Discovery of microbial activity in carbon sinking as a gatekeeper of Earth's deep carbon

Carbon is transported from Earth’s surface to the mantle where the oceanic crust subducts beneath continents. The efficiency of this transfer has profound implications for Earth’s deep mantle and shallow crust, and the proportions of carbon being routed through this mechanism were previously poorly understood. An interdisciplinary team of scientists working in a volcanic region in Costa Rica has now measured that 90% of the carbon released during subduction is trapped within the crust.
Source: EurekaAlert, https://www.eurekalert.org