Arctic permafrost carbon stored in seabed

Researchers from the Alfred Wegener Institute for Polar and Marine Research and MARUM at the University of Bremen published a study in Nature Geoscience on July 31, 2026, examining the fate of organic carbon released from thawing Arctic permafrost into coastal waters. Using sediment cores from off Herschel Island (Qikiqtaruk) in Canada, they found that only about 10% of the terrestrial organic carbon deposited in nearshore sediments is remineralized by microorganisms into greenhouse gases, while the majority remains stored in the seabed. The study indicates that microorganisms prefer fresh marine carbon over older permafrost-derived carbon, suggesting that permafrost carbon may contribute less to atmospheric greenhouse gases than previously feared. The findings provide a benchmark for climate models and highlight the need for further research, including the planned Arctic Pulse campaign in 2027.