THE JOKER – Permafrost

by Duane Nichols on July 14, 2013

Permafrost Releases Methane

THE JOKER – Permafrost

 By. S. Tom Bond, Resident Farmer, Lewis County, WV

There are two phenomena in the Arctic, that bode evil for the future: loss of arctic sea ice and melting permafrost. I’ve read a lot, and it seems no one has a quantitative idea about what will happen when the arctic sea ice cover melts. The absence of ice will let sunlight penetrate the surface and warm the water, rather than being reflected back into space. With ice 80% of the energy is reflected back into space, 20% is absorbed, going into warming the ice and the air above it. With open sea, 80% of the energy is absorbed.

This has the potential of changing both currents in the ocean and in the air, because both water and air become less dense as they warm, and the driver for currents in both is displacement of warm air by cold air and warm water by cold water.

Our present weather pattern is caused by greater warming of the arctic, causing the stratospheric jet stream to move slower and to have north and south meanders several times the amplitude they had previously. This brings arctic weather over a southern area for some longer time, then tropic weather further north, with thunder storms and tornadoes between the regions having different temperatures.

The real joker, though, the great unknown, is permafrost. Permafrost is defined as ground (soil or rock and included ice or organic material) that remains frozen for at least two consecutive years. Permafrost zones occupy up to 24 per cent of the exposed land area of the Northern Hemisphere. Permafrost is also common within the vast offshore continental shelves of the Arctic Ocean. This subsea permafrost formed during the last glacial period when global sea levels were more than 300 feet lower than at present and the shelves were exposed to very harsh climate conditions. Subsea permafrost is slowly thawing at many locations. Permafrost of various temperatures and continuity also exists in mountainous areas, due to the cold climate at high elevations. (By clicking on “permafrost” in the first line of this paragraph one accesses a great map of the permafrost area and much other valuable information about permafrost.)

Permafrost covers almost a quarter of the northern hemisphere and contains 1,700 gigatonnes of carbon, twice that currently in the atmosphere, and could significantly amplify global warming should thawing accelerate as expected, according to a new report by the United Nations Environmental Program. A quantity of this is already in the form of carbon dioxide and methane trapped in the ice, and more will be converted to these compounds by microbial action as the permafrost layer melts, then it escapes into the atmosphere. This forms what is known as a positive feedback. As the warming increases, the rate of release will increase and still more warming will occur as a result, producing more gases. The microbes do not have to be added by contamination, they are already there, ready to “go to work” when thawing occurs.

The source of the carbon is huge amounts of organic matter accumulated over tens to hundreds of thousands of years, buried as the land froze. The permafrost is as much as half a mile thick in places. Where air can get to the organic matter carbon is oxidized to carbon dioxide, and where it can not, anaerobic decomposition results in methane.

The sometime notion that farming can simply be moved North is a fantasy. Subsurface permafrost blocks the descent of water, so it ponds on the surface, forming wetlands.

The surface of thawed permafrost is weak and irregular due to frozen and thawing pockets of water in it. This disrupts buildings, roads, power lines, and other structures, such as drainage ditches, subsurface pipelines (sewers and water) that are needed for concentrations of human habitation.

The big question is quantification of the result of thawing permafrost. How much? How soon? There is very little research about these maters. Vast expenditure would be required to study one-quarter of the Northern Hemisphere at a scale that would give a reasonable level of accuracy. May of the stations studying the effect would have to be in very remote, isolated places. However, we know well that it will happen because there are signs of it now. Pictures of methane escaping from thawing lakes, also here and here. Escaping methane can be measured for a particular area.

Methane leaks under the sea, as well as on land are also known. Scientific American points to an article from the research journal Nature Geoscience which claims over 150,000 such leaks have been found.

We know that sources of carbon exposed at the surface will decompose producing 40% more carbon dioxide and methane than sources that remain buried, but the rate at which they decompose is unknown. However, it is certainly significant, judging from the observations in the previous paragraph.

Aware of this, what should be done? It is a very human tendency to ignore bad news, something we all recognize as being a very bad policy. Those that are making money avoiding bad news will be particularly hard to convince to accept any new policy.

Most problems can be solved by incremental advance and waiting for results.. Most problems will get better in time if the cause is removed. Obviously that procedure isn’t being used with contaminating the atmosphere, and the positive feedbacks.

Where gluttonous continuation of technology that contaminates the atmosphere is involved, it seems a particularly bad idea to throw out the precautionary principle, which is, “first, do no harm.” To let business economics and finance driven politics make decisions about what is essentially an earth scale geology question, “What will happen when the permafrost melts?” is utterly foolhardy.

It’s extreme events that make headlines, but it’s the long view that should make us worried.

{ 2 comments… read them below or add one }

Jackie Braydon July 20, 2013 at 3:26 am

Permafrost is permanently frozen soil, and occurs mostly in high latitudes. Permafrost comprises 24% of the land in the Northern Hemisphere, and stores massive amounts of carbon. As a result of climate change, permafrost is at risk of melting, releasing the stored carbon in the form of carbon dioxide and methane, which are powerful heat-trapping gases. In addition, permafrost is structurally important, and its melting has been known to cause erosion, disappearance of lakes, landslides, and ground subsidence. It will also cause changes in plant species composition at high latitudes.

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S. Thomas Bond July 25, 2013 at 5:18 pm

See also the article “Arctic methane ‘time bomb’ could have huge economic costs” by Matt McGrath at:

http://www.bbc.co.uk/news/science-environment-23432769

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