Preliminary assessments of carbon release driven by Late Pleistocene Arctic ice sheets

Understanding fluctuations in atmospheric CO2 during transitions from glacial to interglacial states is critical for deciphering climate dynamics. This study investigates the influence of Late Pleistocene Arctic ice sheets on organic carbon remobilization and its subsequent effects on atmospheric CO2 concentrations. We demonstrate that the main source of organic carbon deposited in the Arctic Ocean and northern Nordic Seas was derived from glacially exhumed terrestrial and shelf sediments, rather than primary productivity. The degradation of remobilized organic carbon contributed significantly to an increase in dissolved inorganic carbon (DIC), accounting for about 15–26% of the current DIC stock. Such a considerable addition poses a challenge to the ocean's CO2 absorption capacity, potentially converting the Arctic region into a net carbon source. Nevertheless, the uncertainties associated with the age framework, along with the complexity of organic carbon degradation, limit the accuracy of carbon release assessments. Our findings offer new insights into the Arctic Ocean and northern Nordic Seas' roles in global CO2 dynamics, emphasizing the urgent need for more precise studies on the ice sheet-driven carbon release and its broader climatic implications.