Most of the ancient carbon released from thawing Arctic permafrost is being buried in seabed sediments instead of being converted into greenhouse gases, according to a study published in Nature Geoscience.
Researchers studying sediment cores near Herschel Island in Canada’s Arctic found that only around 10 per cent of the carbon transported into the ocean is broken down by microorganisms into gases that can enter the atmosphere. The remaining carbon is largely preserved beneath the seafloor.
The team also found that marine microorganisms preferentially consume fresh organic matter from algae rather than older carbon released from thawing permafrost.
Scientists said the findings improve understanding of the Arctic carbon cycle and could help refine climate models, while noting that more research is needed to determine how much permafrost carbon decomposes before reaching the seabed.