Agricultural soil erosion significantly impacts the global carbon cycle. Studies using cesium-137 and carbon inventory measurements from large-scale surveys found consistent evidence of an erosion-induced carbon sink, equivalent to approximately 26% of the carbon transported by erosion. Based on this relationship, a global carbon sink of 0.12 petagrams of carbon per year (range 0.06 to 0.27) was estimated from erosion in agricultural landscapes. This challenges the view that agricultural erosion is a major source or sink of atmospheric CO₂. Soil erosion removes soil organic carbon (SOC) from its formation site and buries it in depositional environments. Three mechanisms explain how erosion can affect the net carbon flux between soil and atmosphere: (1) replacement of SOC at eroding sites due to continued plant inputs and reduced decomposition; (2) deep burial of both allochthonous and autochthonous carbon with inhibited decomposition; and (3) enhanced decomposition of SOC due to chemical or physical breakdown during transport. The magnitude of the erosion-induced sink or source depends on the rate of SOC replacement, changes in SOC reactivity due to transport and burial, and erosion/deposition rates. Previous global assessments of erosion's impact on carbon dynamics made different assumptions about these factors, leading to conflicting estimates of the net carbon flux. This study used comprehensive data on SOC and cesium-137 inventories from agricultural soils in Europe and the United States to examine the integrated effects of these processes. The results show that agricultural erosion can act as a carbon sink, challenging previous assumptions about its role in the global carbon cycle.Agricultural soil erosion significantly impacts the global carbon cycle. Studies using cesium-137 and carbon inventory measurements from large-scale surveys found consistent evidence of an erosion-induced carbon sink, equivalent to approximately 26% of the carbon transported by erosion. Based on this relationship, a global carbon sink of 0.12 petagrams of carbon per year (range 0.06 to 0.27) was estimated from erosion in agricultural landscapes. This challenges the view that agricultural erosion is a major source or sink of atmospheric CO₂. Soil erosion removes soil organic carbon (SOC) from its formation site and buries it in depositional environments. Three mechanisms explain how erosion can affect the net carbon flux between soil and atmosphere: (1) replacement of SOC at eroding sites due to continued plant inputs and reduced decomposition; (2) deep burial of both allochthonous and autochthonous carbon with inhibited decomposition; and (3) enhanced decomposition of SOC due to chemical or physical breakdown during transport. The magnitude of the erosion-induced sink or source depends on the rate of SOC replacement, changes in SOC reactivity due to transport and burial, and erosion/deposition rates. Previous global assessments of erosion's impact on carbon dynamics made different assumptions about these factors, leading to conflicting estimates of the net carbon flux. This study used comprehensive data on SOC and cesium-137 inventories from agricultural soils in Europe and the United States to examine the integrated effects of these processes. The results show that agricultural erosion can act as a carbon sink, challenging previous assumptions about its role in the global carbon cycle.