Where Does the Carbon Go When Permafrost Coasts Erode?
https://eos.org/research-spotlights/where-does-the-carbon-go-when-permafrost-coasts-erode
Source: By Kate Wheeling, Eos/AGU.
Excerpt: Arctic coastlines have not been considered carefully in carbon cycles for long, but new research suggests that eroding permafrost may emit more greenhouse gases than previously thought. The Arctic is warming faster than almost anywhere else on Earth. As a result, the region is changing rapidly: Glaciers are melting, sea ice is disappearing, and permafrost is thawing, which could accelerate climate change. The northern permafrost region covers roughly a quarter of the land in the Northern Hemisphere and stores vast amounts of carbon—more than double the amount in the atmosphere today—much of it still locked away, frozen. Researchers have known for some time that permafrost could become a major source of greenhouse gases as the soil thaws and once-dormant microbes wake up and break down organic matter. This thaw is accelerated in places along Arctic coasts, where permafrost is eroding into the sea. As sea ice–free conditions in the Arctic expand, cliffs and shorelines are exposed to storms and wave action for longer periods, accelerating erosion. The Arctic’s permafrost coastlines, which make up more than a third of Earth’s coasts, are eroding at an average rate of roughly half a meter per year, though in some spots the rate tops 20 meters per year. Little is known, however, about the fate of the organic carbon in eroded permafrost as it enters the ocean. Climate models assume that it is consumed in primary production or buried offshore. But a new study by Tanski et al. [https://doi.org/10.1029/2019GL084303] suggests that a substantial portion is vented back into the atmosphere as carbon dioxide or other greenhouse gases....
Source: By Kate Wheeling, Eos/AGU.
Excerpt: Arctic coastlines have not been considered carefully in carbon cycles for long, but new research suggests that eroding permafrost may emit more greenhouse gases than previously thought. The Arctic is warming faster than almost anywhere else on Earth. As a result, the region is changing rapidly: Glaciers are melting, sea ice is disappearing, and permafrost is thawing, which could accelerate climate change. The northern permafrost region covers roughly a quarter of the land in the Northern Hemisphere and stores vast amounts of carbon—more than double the amount in the atmosphere today—much of it still locked away, frozen. Researchers have known for some time that permafrost could become a major source of greenhouse gases as the soil thaws and once-dormant microbes wake up and break down organic matter. This thaw is accelerated in places along Arctic coasts, where permafrost is eroding into the sea. As sea ice–free conditions in the Arctic expand, cliffs and shorelines are exposed to storms and wave action for longer periods, accelerating erosion. The Arctic’s permafrost coastlines, which make up more than a third of Earth’s coasts, are eroding at an average rate of roughly half a meter per year, though in some spots the rate tops 20 meters per year. Little is known, however, about the fate of the organic carbon in eroded permafrost as it enters the ocean. Climate models assume that it is consumed in primary production or buried offshore. But a new study by Tanski et al. [https://doi.org/10.1029/2019GL084303] suggests that a substantial portion is vented back into the atmosphere as carbon dioxide or other greenhouse gases....