Permafrost contains large amounts of biomass and decomposed biomass that has been stored as methane and carbon dioxide, making tundra soils an effective carbon sink.
The structure of the permafrost ice sheet. From above = active layer, ice slices, then permafrost layer that is divided into 2, permafrost layer with low ice content above, and rich ice content below, at the bottom there are melted silt deposits (Mulhern, 2020).
As global warming heats ecosystems and causes soil liquefaction, the permafrost carbon cycle accelerates and releases many of the greenhouse gases contained in these soils into the atmosphere, creating a feedback loop that accelerates the process of climate change.
Alaska's Noatak National Protected Forest, one very warm summer in 2004 triggered a 300 m long slide associated with melting ice sheets. (Bykova, 2020).
The Relevance of the Melting of the Northern Earth's Permafrost Ice Sheet to Global Warming and Climate Change
In Earth's northern latitudes, temperatures have increased by 0.6 degrees Celsius per decade over the past 30 years, twice as fast as the global average (IPCC, 2013). This causes normally frozen soils to thaw (Romanovsky, 2013), exposing large amounts of organic carbon for decomposition by soil microbes.Â
This permafrost carbon is the remains of plants and animals that have accumulated in perennially frozen soils over thousands of years, and the permafrost region contains twice as much carbon as is present in the atmosphere today (Tarnocai, 2009). The conversion of only a fraction of this frozen carbon pool into the greenhouse gases carbon dioxide (CO2) and methane (CH4) and their release into the atmosphere could increase the rate of future climate change.
Soil organic carbon deposits (kg/m^2) are contained in 0--3 m depth intervals from northern circumpolar permafrost areas (Schuur, 2015).
