Permafrost Threatened by Rapid Retreat of Arctic Sea Ice

A new study by the National Snow and Ice Data Center and the National Center for Atmospheric Research has warned that the integrity of carbon and methane sequestering permafrost is threatened by the rapid retreat of Arctic Sea Ice. This comes at the same time as warnings that this summer may see the first ice-free North Pole for the first time in recorded history.

The rate of climate warming over northern Alaska, Canada, and Russia could more than triple during extended episodes of rapid sea ice loss, according to a new study from the National Center for Atmospheric Research (NCAR) and the National Snow and Ice Data Center (NSIDC). The findings raise concerns about the thawing of permafrost, or permanently frozen soil, and the potential consequences for sensitive ecosystems, human infrastructure, and the release of additional greenhouse gases.

"The rapid loss of sea ice can trigger widespread changes that would be felt across the region," said Andrew Slater, NSIDC research scientist and a co-author on the study, which was led by David Lawrence of NCAR. The findings will be published Friday in Geophysical Research Letters.

Last summer, Arctic sea ice extent shrank to a record low. From August to October last year, air temperatures over land in the western Arctic were also unusually warm, reaching more than 4 degrees Fahrenheit (2 degrees Celsius) above the 1978-2006 average. This led the researchers to question whether the unusually low sea ice extent and warm land temperatures were related.

The report's findings show a link between rapid sea ice loss and an increased rate of global warming, potentially moving up to 900 miles inland and in areas where permafrost is already at risk, i.e. central Alaska, where periods of abrupt sea ice loss could lead to uncontrolled soil thaw.

Thawing permafrost may have a range of impacts, including buckled highways and destabilized houses, as well as changes to the delicate balance of life in the Arctic. In addition, scientists estimate that Arctic soils hold at least 30 percent of all the carbon stored in soils worldwide. While scientists are uncertain what will happen if this permafrost thaws, it has the potential to contribute substantial amounts of greenhouse gases to the atmosphere.

Permafrost is known to hold large amounts of both carbon and methane, a greenhouse gas many times more potent than C02. While the impact of both gases' release into the environment requires further study, it would be, as the above NSIDC quote states, substantial.

More on this topic at The Environmentalist

Comments

[mamacat]

As the author mentioned, there is the possibility that huge amounts of methane could be released this summer from a melting permafrost.

It normally takes only about 15 years for methane to disappear from the atmosphere, but during those 15 years, methane is a much, much stronger acting green-house gas than is an equal amount of CO2. Thus, the possibility for a cascade event, or feedback loop, is something to worry about.

It is far from certain, but the possibility of a logarithmic increase in the rate of atmospheric heating now exists.

[zaneblue]

That's the scariest thing about global warming--irreversible feedback loops.