2011-08-24 11:06:37Not so Permanent Permafrost
Agnostic

mikepope_9@hotmail...
118.208.151.27

Introduction

Permanently frozen ground or permafrost occurs and persists where the mean temperature above ground is 0°C or less, resulting in soil, rock and their content being frozen and remaining frozen for at least 2 consecutive years. Permafrost is most common in higher latitudes of the northern hemisphere where it occurs over 24% of the landmass. It commonly has a depth of 0.6-150 metres though depths of1,500 metres are known.  Soil temperature below 5 metres tend to remain stable even though surface temperature may seasonally thaw the active zone where limited plant growth is possible.

The content of soil affected by permafrost often includes water, accumulated organic matter (biota) and methane produced from biota decay when temperatures were warmer.  The presence of permafrost prevents such decay and methane emission.  Water contained in the soil is present in the form of ice which binds composite material together.  The presence of ice, often close to the surface, prevents water flow so land affected by permafrost tends to be poorly drained and to be swampy or peatland when the active layer thaws briefly in summer.  Thawing usually occurs from the surface downwards and in the Arctic seldom penetrates more than 1 metre.

In the Arctic and adjacent lands, where sub-surface temperature is lower than -5°Cpermafrost is continuous, ice in the soil is near the surface but is sensitive to temperature and within a degree or so of thawing.  Where sub-surface temperature is between -2°C and -4°C, permafrost is discontinuous, is present in 50%-90% of the land area and ice near the surface is within a fraction of a degree of melting.  Partial permafrost can form where sub-surface land temperature is 0°C to -2°C and occurs in 10%-50% of the land area though ice is usually not found close to the surface, permitting more diverse flora and fauna to flourish.

Fig. 1  Distribution of permafrost.  Continuous occurs in 100% of land area, Discontinuous occurs in 50-90% of land area, Sporadic occurs in 10-50% of land area.  Courtesy Riccardo Pravettoni, UNEP/GRID-Arendal 

Permafrost thaws when the land surface is disturbed or when temperature above the surface exceeds 0°C.  Anthropogenic activities have now elevated CO2 in the atmosphere causing warming to levels where on-shore permafrost is beginning to thaw, enabling decay of biota to resume and stored CH4 to be emitted into the atmosphere at an accelerating rate. In 2005 Shakhova et al (2010) measured methane entering the atmosphere from the East Central Siberian (ECS) continental shelf at 8 million tonnes per annum.  It is estimated that onshore emissions from thawing yedoma and biota are presently ~4 million tonnes per annum.

Greenhouse gas emissions

Yedoma is a Pleistocene permafrost rich in organic material and loess bound together by ice which makes up 50-90% of its content.  It is most commonly found in Eastern Siberia where it covers ~1 million km2 and can be >20 metres thick. Because of its high ice content, thawing and refreezing produces a thermokarst landscape of ponds and lakes (Fig 3) permitting biota to resume decay and emit greenhouse gases. Yedoma contains about 2% methane by volume and Siberian deposits, estimated to contain over 500 gigatonnes, are a major source of this gas.

All of the gas escaping from these sources enters the atmosphere as CH4 with a Global Warming Potential ~72 times greater than CO2 over a 20 year time horizon during which CH4 oxidizes to CO2.  It therefore has an immediate and powerful warming affect on the Arctic and contributes to temperature amplification in this and sub-Arctic regions.  It is estimates that annual methane emissions in the Arctic will increase to 1.5 billion tonnes of carbon per annum before 2030 and Shakhova predicts that emissions from the ECS alone could rise to >3 billion tonnes per annum later this century.

Releases of this magnitude are predicted to increase average global temperature by at least 4°C-6°C and by 6°C - 10°C in the Arctic before 2100.  Importantly, combined with loss of Arctic sea ice, it will also produce considerable warming of ocean water.  Inevitably, melting of permafrost, already evident, will accelerate significantly in coming years, both onshore and on the seabed.  Assessment of the effects this will have is important so that we are aware of the consequences and, where possible, can plan and institute remedial or mitigating action.

The Arctic tundra covers an area of ~10.360m km2 and is covered by continuous permafrost.  It is estimated that this area contains an incredible 1.5 trillion tonnes of CH4, some stored in clathrate far beneath the surface, much of it in frozen biota at near surface depth, covered in permafrost insulating and stabilizing that material.  Surface permafrost has probably been slowly melting since CO2concentration in the atmosphere rose above 280 ppm and has been releasing progressively larger CH4 amounts each year.

 

Fig. 2  Actual and projected loss of permafrost.  By 2100 permafrost will have thawed to a depth of 3 meters producing slope instability in mountain areas.  Courtesy UNEP/GRID-Arendal 

Since 1988 when CO2 reached 350ppm, the rate and extent of permafrost thaw has increased significantly, and, combined with reduced albedo, elevating temperature – a feature known as Arctic amplification, speeding-up carbon feedback.  The effects of this are evidenced by Landsat and other data sources, showing coastal erosion over the 30 years 1986-2005 was double that of the preceding 30 years.

Arctic warming, consequential thawing of permafrost and associated carbon feedback are expected to accelerate the rate of thawing throughout the 21stcentury.  As permafrost thaws it permits biota to resume decay, producing methane and emitting it at a much increased rate.  Wickland et al (2006) find that poorly drained peat soils in Alaska emit 15 to 28 times more greenhouse gas when free of permafrost than do soils where permafrost is present.

Lawrence et al (2005) estimate that permafrost covering ~9.5m km2 will have thawed to a depth of 3 meters by 2100.  This thawing will make sediments wet, plastic and unstable producing change to the land surface through formation of wetlands, gullies and sinks.   It results in land subsidence and expansion causing land surface distortions, reducing its load bearing capacity and producing instability of mountain slopes.   The latter is exacerbated when permafrost refreezes, producing massive slides of rock, gravel and other material.

 

Fig 3.  Wet Tundra in the Russian Arctic.  Thawing of surface permafrost creates poor drainage causing them to turn into soggy bogs in summer which re-freeze in winter, a typical thermokarst landscape.  Courtesy UNEP/GRID-Arendal 

Flora and Fauna

Over the 21st century, extensive melting of permafrost will produce geomorphology substantially changing the existing environment.  Tundra plants are limited to grasses, sedges, lichens and mosses which have specialized to withstand the harsh Arctic climate and limited hours of sunshine.  They are being displaced by sub-Arctic flowering plants, small shrubs and trees.  The tree-line is predicted to move north encroaching on tundra at rates of up to 6 kilometres  a year in some places, though generally slower advance is predicted. 

Animal species which are well adapted to tundra flora and climate are highly susceptible to environmental change.  It is likely that many could be faced with extinction unless they can adapt to a rapidly changing environment.  Rising temperatures and spread of flora found south of the tundra will limit food availability for grazing animals such as moose, caribou, reindeer and musk ox. Melting permafrost will cause development of extensive swamps, likely to impede migrating animals and their vulnerable young.  Reduction in their number will in turn threaten predator species such as wolves and Arctic fox.

Coastal erosion

Expectations are that erosion of the coastline will occur where there is a rise in sea level.  Bruuns Rule states that on average each 1cm of sea level rise results in about 1m of coastal recession.  In other words, for each meter of sea level rise, the coastline is eroded, over time, by 100 meters.  While this Rule has global application, coastal erosion in the Arctic is occurring at a much faster rate than predicted because of permafrost thawing and exposure of shorelines to wave action.

Around 60% of the Arctic Ocean shoreline is stabilized by permafrost binding silt, gravel and other material together.  Until recently they have been protected by sea ice from ocean wave action, however coastlines are remaining ice-free for longer periods each year.  Shorelines are now seasonally exposed to relatively warm seawater, the erosive action of waves and autumnal storm surges.  The result is that binding permafrost is being melted and shorelines are being eroded by wave action by up to 20 meters per annum in some parts, particularly at river deltas.  This threatens human settlements, salinates fresh water sources and damages other habitat.  The entire Arctic coastline has become labile, markedly so along shorelines of the Laptev, East Siberian and Beaufort seas.

Fig 4.  Coastal erosion is extensive along Arctic Ocean shorelines, particularly of the Laptev, East Siberian and Beaufort Seas.  Courtesy Riccardo Pravettoni,UNEP/GRID-Arendal

Global average sea level rise is presently 3.3mm per annum so, according to Bruuns Rule we should be seeing average coastal erosion ~33cm per annum.  In the Arctic we find average erosion along 100,000 km of coastline is 1-2 meters per annum.

Socio-economic effects

All of the Arctic landmass, generally defined as the area contained by the 10°C thermoline, is affected by permafrost.  The Arctic has a population of 4-5 million(half living in Russia), several sizeable cities and major extractive industries - particularly oil and gas.

These are supported by an extensive transport infrastructure including roads, railways, bridges, airports, pipelines, dams and port facilities.  Cities and smaller settlements comprise dwellings, schools, hospitals, industries and businesses, as well as water and sewage treatment facilities.  Many of these assets are built on what were solid permafrost foundations often less than 3 metres deep.

Vast sums of money and decades of human endeavour in creating these assets will be at increasing risk where the foundations on which they rest, permafrost, begin to melt.  This melting has already started and is expected to accelerate and become more extensive throughout the 21st century.  It can be slowed by reducing CO2emissions but it can no longer be stopped, except by the onset of an ice age and there is no known defence against its ruinous effects

It is likely that in a decade or so, many more structures will be at risk of collapse or becoming unusable due to instability of the ground on which they are built.  The load bearing capacity, alignment and stability of roads and bridges may be adversely affected and ground traversed by gas and oil pipelines may no longer be able to support their weight.

The socio-economic impact of these developments is likely to be significant over the next 50 years.  The largest industries throughout the Arctic involve mineral, oil and gas production.

  • In the Russian Arctic, they are particularly important, accounting for 11% of GDP, 75% of the oil and all of the gas needed for domestic consumption and ~22% of Russia’s exports.
  • In the Canadian Arctic, diamond mining is presently the largest industry though gold tungsten and other minerals are also produced.  Considerable oil and gas reserves are planned to be developed.  Apart from Yellowknife (19,000) there are no towns of any size.
  • In Alaska, oil and gas production are the largest component of the State economy while zinc mining in the north-west makes an important contribution. The Alaskan Arctic has no major cities, though Fairbanks (35,000) is built on permafrost affected land.

Commercial activities in the Arctic are large, important to national economies and for the viability of local population centres.  Monitoring of permafrost melting and associated greenhouse gas emissions is undertaken by ground instruments and satellites.  However, unless technology able to replace melting permafrost with an affordable, durable load bearing foundation can be applied, it should be accepted that virtually all existing buildings and structures located on permafrost with foundations less than 5 metres deep are likely to be damaged or destroyed before 2100.

Conclusions

Permafrost is an immense CH4 reservoir and although present levels of emission are low, they are expected to substantially increase this century, accelerating warming in higher latitudes and globally.   This is a major concern since it will produce growing feedback resulting in gradual increase of the speed, depth and extent of permafrost thawing further increasing CHemissions.  The result will be on-going and more extensive land destabilization, distortion of surface and subsurface material and development of swamplands.

These will have profound impacts on flora and fauna, particularly species which have adapted to tundra conditions.  Because of the speed and extent of permafrost thawing, they may have insufficient time to adapt to these changes and could face extinction.  At the same time, warming and other changes to the environment are resulting in northward movement of species.

Permafrost loss combined with retreat of sea ice is producing very rapid coastal erosion in the order of 5-6 times faster than that caused by rising sea level.  It is affecting some coastal communities, causing them to move to more stable land.  More significant will be the damage to buildings and infrastructure now becoming evident as a result of land movement caused by loss of permafrost.  This damage is expected to increase over the next 50 years, and have substantial adverse effects on the Arctic economy.

These outcomes may be slowed by rapid reduction of anthropogenic greenhouse gas emissions but they can not be stopped or reversed.  Without application of technology countering the effects of permafrost thawing on existing buildings and infrastructure, damage to them can not be prevented.  Nor can a dangerous increase in the venting of CH4 into the atmosphere.


2011-08-24 11:10:49
Agnostic

mikepope_9@hotmail...
118.208.151.27

I have 3 graphics/1 picture to insert into the text but still have no idea how to upload them, let alone insert them and I need simple easy to understand instructions on how to do so please - and I do mean "simple" because apart from knowing how to use a laptop for research and writing an essay, I am computer illiterate.

2011-08-24 14:44:09adding graphics
dana1981
Dana Nuccitelli
dana1981@yahoo...
69.230.106.125

Very simple - go to Author Admin (which is also liniked on the main page in the left margin).  Click the Upload Image link, and then browse for the graphic and upload it.

2011-08-24 18:37:21
Rob Painting
Rob
paintingskeri@vodafone.co...
118.93.235.101

Agnostic - have you seen this?

Thawing Permafrost could release vast amounts of carbon and accelerate climate change by the end of this century

The study (Koven (2011) is paywalled.

So even increased plant growth in the Arctic won't be enough to offset the release of CO2 from permafrost (I guess that in itself is worthy of a separate rebuttal) 

2011-08-25 10:24:37
Agnostic

mikepope_9@hotmail...
118.208.151.27

Rob Painting

Thank you for that.

Yes, I have just drafted a seperate article "Abrupt Climate Change - Its Causes" which covers this aspect.  There is no way that additional plant growth enabled by permafrost thawing could negate the effects of carbon releases, particularly since most of the releases result from thawing of permafrost on the seabed of the continental shelf where plant growth is impossible.

Sharkhova et al 2010 warns that the release of 1% of Arctic carbon deposits is sufficient to cause abrupt climate change.  So does Archer.  This century is going to become increasingly difficult for our survival and it began with thawing of permafrost initiated by anthropogenic CO2 last century. Hence the present article.

 

2011-08-25 10:29:06
Agnostic

mikepope_9@hotmail...
118.208.151.27

Dana 1981

Thanks.  Done that, though I have yet to discover the result.

Now, can you explain how you linked the words Author Admin to the source URL?

2011-08-25 14:50:52
scaddenp

p.scadden@gns.cri...
161.65.53.59

Are you aware of this discussion of Shakhova at Realclimate?

2011-08-25 15:30:39links
dana1981
Dana Nuccitelli
dana1981@yahoo...
69.230.106.125

Agnostic - to create a link, just highlight the desired text and use the button that looks like a couple of chain links.

When you add an image, it will give you the SkS URL.  It should look like this:

http://www.skepticalscience.com/pics/[your image filename]  

i.e.  http://www.skepticalscience.com/pics/TarSandsGoogle.png

To insert an image, use the button that looks like a tree.  Make sure under "Appearance", you limit the vertical dimension to 500 pixels.

Here's the link to the post by the way: Not so Permanent Permafrost

2011-08-25 15:53:40
Agnostic

mikepope_9@hotmail...
118.208.151.27

Scaddenp

Thanks for that.  No I was not aware of it and thank you for drawing it to my attention.

I would note that while CH4 emissions near Spitzbergen will oxidise to CO2 when passing through a 300-400m water column before entering the atmosphere, emissions from the East Siberian continental shelf (ESCS), passing through a water column of 50m or less, do enter the atmosphere as methane where they remain present for 10-15 years, during which period it has a global warming potential of ~72.

Shakhova rightly expresses concern that ESAS methane deposits, estimated at 1,400 billion tonnes, are under pressure and becoming more unstable because of thawing of permafrost due to warming Arctic waters and gepthermal heat associated with siesmicity.  She goes on to note that continued thawing of seabed oermafrost on the ESAS increasingly risks eruption of CH4 in quantities >3 billion tonnes per annum - sufficient to bring about abrupt climate change.  She notes that growth of CH4 emissions are not adequatly monitored and, in view of their threat, should be.

In my view, we have initiated a dangerous, uncontrollable slow feedback through anthropogenic CO2 emissions and there is nothing we can do except argue that, it doesn't pose a serious threat, it doesn't matter. We certasinly can not put this genie back in the bottle.

2011-08-25 18:01:08
scaddenp

p.scadden@gns.cri...
203.109.223.176

Just for variation, here is a supporting paper. http://www.atmos.washington.edu/academics/classes/2011Q2/558/IsaksenGB2011.pdf

 

Last time I talked to our methane hydrate researchers, they thought risk was overstated, but are keenly interested. Would you like me to ask one of them (Ingo Pecher) to cast an eye over this?

2011-08-25 19:05:40
scaddenp

p.scadden@gns.cri...
203.109.223.176

Poking around, I found this too. Estimating rate of arctic methane release.

2011-08-26 09:33:54
Agnostic

mikepope_9@hotmail...
118.208.151.27

scaddenp

 

Thanks for the references.  The Isaksen Paper is very readable.

Please do invite Dr Pecher to read the article.  I would certainly welcome the views of an expert - and it would be good if they were published by SkS.

I am of course aware that thawing of permafrost is regarded by some as of little importance – a slow process posing no threat to the environment or human activity in the Arctic and is unlikely to do so this century – von Deimling et al.

Others (me included) hold that warming Arctic Ocean waters will continue to thaw permafrost on the continental shelf releasing methane deposits beneath it.  Those deposits include hydrates and methane gas under pressure, leaking into the atmosphere and, at least seasonally, contributing to Arctic atmospheric warming.  That warming will contribute to melting of tundra permafrost, including significant shallow yedoma deposits.

When that occurs (there is ample evidence it already is) we should all be worried about the effects of increasing methane emissions and their effects of global warming and Arctic amplification.  The problem is exacerbated by the fact that permafrost thawing first occurs at the surface, both on the tundra and on the continental shelf, so that methane has no chance of oxidizing before entering the atmosphere.

These are matters I discuss more fully in a follow-up article which I rather fancy will cause many to challenge and reject it, though others will at least consider it as raising valid concerns.  But, as they say, you can’t make an omelet without breaking conservative views!

2011-08-26 13:06:19
scaddenp

p.scadden@gns.cri...
161.65.53.59

Ingo has agreed to look at it over the weekend - but his first reaction was sympathetic and doesnt think it is alarmist.

2011-08-31 15:38:30
Agnostic

mikepope_9@hotmail...
118.208.151.27

Dana1981

Problem is, 1. I cant access my original posting for editing and 2. Nor can I see a button that looks like a tree.  Now what??

I warned John that when it came to using a computer for complex things other than research, e-mails and writing, I was an idiot.  Guess this confirms it!

2011-08-31 18:31:55
Ari Jokimäki

arijmaki@yahoo...
192.100.112.211

Here are some papers on permafrost thawing.

2011-09-01 03:25:22
dana1981
Dana Nuccitelli
dana1981@yahoo...
64.129.227.4

Agnostic, you should be able to access this page for editing: Not so Permanent Permafrost

The tree (insert image) button is between the one that looks like an anchor and the one that looks like a paintbrush.

2011-09-01 06:44:10Comment
Robert Way

robert_way19@hotmail...
142.163.190.161

Sending the article to this guy:
http://www.geography.uottawa.ca/prof/alewkowicz.htm

First and asking him what he thought of it might be appropriate too. Editor of Permafrost and Periglacial Processes (He's usually quite good with answering).

2011-09-01 11:08:35
Agnostic

mikepope_9@hotmail...
118.208.151.27

Robert - Thanks for inviting Professor Lewkowicz to have a look at Not so Permanent Permafrost 

I have sent him an e-mail requesting his views but I would also be interested in your views.

2011-09-01 11:56:57
Agnostic

mikepope_9@hotmail...
118.208.151.27

Ari - Thank you for the reference to AGW Observer.  Some interesting papers.

2011-09-02 14:14:17
scaddenp

p.scadden@gns.cri...
161.65.53.59

Here is comment from Ingo Pecher.

"Phil, sorry for my sluggish response.

First, I am not an expert in permafrost.

The article reads fine and is certainly not alarmist - if anything, it may be conservative....

My only comments are
- You need to distingusih between offshore permafrost (which to my knowledge is a thin wedge that is melting "naturally" following flooding of the shelf) and onshore permafrost, which is melting because of atmospheric warming.
- Provide a reference for the warming effect of CH4 relative to CO2 -- I've seen various numbers
- Check with Shakhova: http://www.iarc.uaf.edu/people/nshakhov

Cheers -- Ingo"

2011-09-02 15:33:15
Agnostic

mikepope_9@hotmail...
118.208.151.27

Scaddenp

According to Shakhova, there is nothing "natural" about the melting of permafrost on the continental shelf.  She asserts that it is primarily due to warming Arctic Ocean waters and to a lesser extent by geothermal heat associated with siesmicity of the shelf.

Neither the shelf nor the permafrost on it are a "thin wedge".  The area involved is 2.1x10km- and that is only the ECS and does not include the continental shelf covered by the Chuchki, Beaufort, Lapechev or Kara seas.

In fact I do provide a reference to the GWP difference of CO2/CH4.  Perhaps it was not apparent in the copy on which Dr Percher commented.  

Please thank Dr Percher for taking the time to read the article.  I will improve clarity on the issue of atmospheric warming causing loss of on-shore permafrost.

2011-09-07 12:12:03HELP!
Agnostic

mikepope_9@hotmail...
118.208.21.4

Dana 1981

I followed your advice and using the "tree" inserted the 4 figures I want to include but, despite repeated attempts, they never appeared - as you can see - so I can not edit them to ensure they are the right size.

Obviously I am doing something wrong - but what??

2011-09-07 14:23:54
dana1981
Dana Nuccitelli
dana1981@yahoo...
69.230.106.125

I don't know Agnostic.  All you should need to do to get the images in there is click the tree button, paste the URL, and click the "Insert" button.  If you post the image URLs, I can put them in there for you.

2011-09-07 16:34:34
Rob Painting
Rob
paintingskeri@vodafone.co...
118.92.36.19

Agnostic - when you click on the tree icon, the menu will come up allowing you to paste in the link. After pasting the link, rather than clicking immediately on 'insert', go to the 'appearance' tab at the top of the pop-up menu and re-size the image (max width is 570 wide), don't worry about the 'height', it will automatically reconfigure. Once done click 'insert' and it should be done.

I'm assuming that you are inserting images too large to display, and the html editor is 'spitting the dummy'. Maybe that's the problem?

2011-09-08 05:40:31
Andy S

skucea@telus...
66.183.179.249

I'm not sure what you mean by the "10°C thermoline". Murmansk, Tromso and Reykjavik are not in permafrost regions (and Reykjavik is not in Arctic latitudes). Perhaps you should exclude these cities from the discussion of the effects of melting premafrost.

"Yellowknife" is one word.

I think that what Dr Pecher meant by "natural thawing" of the submarine permafrost is that this is a process that has been going on since post-glacial sea level rise in the early Holocene, 10,000 years ago, long before the industrial revolution. Of course, this process may be speeded up by anthropogenic warming of the sea in coastal areas.

I don't think that melting of clathrates is a big risk over a timescale of centuries because the clathrates on land (or in shallow seas) are buried under thick permafrost (hundred of metres) and will take ages before they feel the effects of AGW. The clathrates in marine environments are typically in deep water and will respond very slowly to increased heating; also the methane released will probably not make it to the atmosphere. I'm much more concerned with the direct effects of permafrost releasing methane and CO2.

I have a paper from the Geological Survey of Canada modelling the response of clathrates to climate change if anyone is interested, email me agskuce@gmail.com

2011-09-08 09:32:40
Agnostic

mikepope_9@hotmail...
118.208.21.4

Andy S

Thank you for your critique – most welcome.

You are right.  Tromso and Murmansk are not affected by permafrost though their hinterlands are.  I have amended the article accordingly.

Dr. Shakhova asserts that thawing of permafrost on the continental shelf is being speeded up by warming water over the shelf which, for 75% of its area is less than 50 metres deep.  This shallowness ensures that methane from sub-surface clathrate and material on the surface of the continental shelf reach the atmosphere unoxidised.  Similarly, methane released as a result of thawing of onshore permafrost (esp. yedoma) enters the atmosphere as unoxidised methane.  This is now occurring at an increasing rate.

In both cases, these releases will have GWP of ~72 during prior to oxidizing in the atmosphere.  Given the magnitude of these near surface deposits (~3,000 gigatonnes) should we not be concerned about their potential to amplify Arctic and global warming?

I agree with you that methane emission from clathrate deep beneath the surface do not pose an immediate problem.  I also agree that methane released from deposits covered by >400 metres of water are likely to be fully oxidise in the water column and reach the atmosphere as CO2.  The point I make is that initial, more immediate thawing of permafrost, on the Arctic continental shelves and on-shore, will release methane which has no time to oxidise, due to its proximity to the surface, before entering the atmosphere.

Interestingly, Dr Shakhova notes that methane deposits are typically found, world-wide, on continental shelves often covered by relatively shallow water.  If these deposits are on or close to the surface of the continental shelves, then warming ocean water could pose a wider problem than is generally accepted.

2011-09-08 10:39:49
Agnostic

mikepope_9@hotmail...
118.208.21.4

Rob Painting - Thanks for the advice.

Its not only the html editor that’s spitting the dummy!

I have sized the graphics to say 400 x 350 px for example, then press enter.  A message comes up alerting me that I have not filled in  “image description” and this may disadvantage some users.

I ignore the message and press the insert button because (a) I am not sure what to insert as “image description” and (b) whatever I enter appears on the image being entered – which is not what I want.

What I get is a space for image I want and in the centre, a small blue square with a "?" in the middle of it - which is also not what I want

So, is the mistake I am making, not filling in “image description” or “title” beneath it?

2011-09-08 12:24:28
dana1981
Dana Nuccitelli
dana1981@yahoo...
69.230.106.125

Sounds like the problem is with entering an incorrect URL.  What are the URLs for your images?

2011-09-08 12:30:37
Andy S

skucea@telus...
66.183.179.249

Agnostic, email me the figs and I'll post the links for you here.

As far as I know clathrates are not stable above 200 metres or so, even at Siberian temperatures, so I doubt that the gas Shakhova saw was clathrate liberated by recent climate change. More likely, it was shallow biogenic gas that was released as subsea permafost melted. There was no geology nor any isotopic analysis of the methane in that Shakhova paper so it was difficult to know just what she found. There are gas seeps in the onshore Mackenzie Delta that are leaking thermogenic gas originally generated from a few thousand metres down. It's also mixed in with a bit of shallow biogenic gas, if I recall correctly. It's possible  that what's happening there is that as the surface warms, previously impermeable permafrost layers are getting perforated and letting some trapped gas out. Perhaps the same thisng is happening in the East Siberia offshore but that's speculative.

2011-09-08 15:55:17
Agnostic

mikepope_9@hotmail...
118.208.21.4

Andy S

Stability of methane clathrate is determined by temperature and pressure.  It usually forms under conditions of 0°C and ~50 atmospheres.  It occurs in and just beneath seabed permafrost where it remains stable at depths of less than 100 metres provided temperature is below 0°C.  At higher temperature it remains stable though only at greater depths.  Seabed deposits are known at depths of 200 – 400 meters where temperature is around 0°C. 

Large deposits on or just beneath the seabed have been located at various locations around the world. In the Krishna-Goodavari Basin off the Indian east coast clathrate over 100 meters thick has been found on the seabed.  Lumps of the stuff have even been brought to the surface in fishing nets.  Given the origins of methane clathrate, it is hardly surprising that they should be commonly found on near and under colder parts on continental shelves world-wide.  In warmer waters it is only found in deeper water such as the Nankai Trough off Honshu, the Ulleung Basin in the Sea of Japan.

However, ocean waters are getting warmer at increasing depth, as evidenced by the methane emissions from the 400 metre seabed west of Spitzbergen.  That warming will continue.  It will produce increasing instability of clathrates on the seabed and just beneath it.   And that will result in growing methane emissions

Thanks for the invite to post my pics.  As soon as I can find them agaun, you shall have them

2011-09-09 03:01:09Figure uploads
Andy S

skucea@telus...
66.183.179.249

Agnostic:

I have uploaded your figures to the links below. The problem you had was that the figures were more than 500 pixels wide, so I had to shrink them. Also the "canvas" they were on was often larger than the images themselves, so I shrank them too.

http://www.skepticalscience.com/pics/1_Fig.1observed-distribution.png

http://www.skepticalscience.com/pics/1_Fig.2loss-of-permafrost.png

http://www.skepticalscience.com/pics/Fig.3wet-tundrasm.jpg

http://www.skepticalscience.com/pics/1_Fig.4arctic-ocean-3.png

These ought to load up nicely using the "tree" icon, like this for Fig 1:

2011-09-09 03:39:09
Andy S

skucea@telus...
66.183.179.249

Agnostic:

I know that hydrate stability depends on temperature and pressure, that was my point actually. Stable hydrates basically don't exist at any temperature above about 200 metres of water or sediment.

 

You may find this article on the offshore permafrost at Barrow, Alaska to be of interest. It shows the zone for permafrost and the stable zone for hydrates. It also models the effect of rising sea levels over the shelf during the past few thousand years.

It's possible that some of the gas that Shakhova observed was originally hydrate that destabalized over the past few thousand years and that was trapped until recently under shallow permafrost that was recently melted by the warming Artctic Ocean. What I don't think is possible is that recent AGW has had any effect on existing stable hydrates (if any) under the E Siberian Shelf because they will be too deep for the temperature change to have penetrated that far down. (yet).

I'm not arguing that methane from hydrates will not play a role in climate change over millennial timescales, I'm sure it will. I just don't think that there will be any big increased role from destablizing hydrates over the next century or three as a result of AGW. I believe also that that is the consensus view held by David Archer & co. But I've been wrong before. In any case, this does not detract in any way from concerns that melting permafrost will be an important positive feedback in climate change over the next few decades, which is your main point, I think.

PS I stumbled upon this website that contains some well-reseached and readable accounts of the role of methane in climate.

2011-09-09 09:53:05
Agnostic

mikepope_9@hotmail...
118.208.21.4

Andy S.

Thank you for the Romanovsky Paper.  I agree with what it says and I also agree with you that methane clathrate is unstable at depths above 200 metres.  However, could conditions exist where clathrate located at shallower depth may be stable if encased in or beneath an enclosing permafrost cap?

I think Shakhova and Semiletov have shown that methane clathrate located beneath the surface of the East Siberian Continental Shelf may be less than 200 metres beneath the surface and is venting methane.  They argue that gas releases under a permafrost cap have occurred due to heat associated with seismicity of the region, creating pressure and that venting occurs because warming seawater is thawing covering seabed permafrost enabling creation of channels through which methane vents to the atmosphere unoxidised.

The magnitude of methane deposits sub shelf seabed (1,400 gigatonnes) and the area they cover (~1.5 million km2) of the East Siberian Continental Shelf and continued warming of covering water are increasing permafrost thawing.  It seems to me these conditions present very real potential for venting of methane in ever increasing volumes.

In addition, methane contained in on-shore areas of continuous and discontinuous permafrost on or near the surface (yedoma and biota which will resume methane producing decay if permafrost thaws) is becoming more unstable.  As on-shore permafrost thaws, which it is now doing at an accelerating rate due to AGW of the atmosphere, methane venting from this source will increase. 

I agree that methane clathrate deeper beneath the surface covered by continuous on-shore permafrost is less likely to be exposed to the effects of a warmer atmosphere initially.  However, continued warming at the surface will ultimately result in clathrate destabilisation and shallower deposits could release methane this century.

Combined, on-shore and continental shelf deposits of methane in the Arctic exceed 3,000 gigatonnes and pose a very serious threat to our climate.  If, as I suspect, annual venting reaches >0.1% of this by the end of this century - not in millennia - then we are in big trouble.

Again, many thanks for your assistance in fixing the vexing pics.

2011-09-17 06:21:16
Agnostic

mikepope_9@hotmail...
118.208.81.161

Robert Way

Have you received any comments from Professor Lewkowicz yet?

2011-09-18 00:12:59
logicman

logicman_alf@yahoo.co...
86.177.54.84

Excellent article!

 

Obligatory typo spotting from an aging pedant:  ;-)

Soil temperature below 5 metres tend to remain

suggestion:  plural - temperatures.  For the singular you need to use 'tends', but since there are many locations, depths and even types of permafrost, I think that the use of the plural 'temperatures' is most apt.

 

Images:

I had to be shown this, despite my geekish tendencies, so now I'm passing it on -

go to author admin;

select 'upload image';

put your image in your section of the SkS site;

note the URL where the image is stored;

in the article, where it asks for the URL, use the one you just noted.

Praying as you click the final button usually helps.  :-)

2011-09-18 14:09:04
Agnostic

mikepope_9@hotmail...
118.208.81.161

logicman - Thanks.  In my case prayer did not work but then I am agnostic where religion is concerned so Andy S saved the day - though I am not sure how.

2011-09-22 17:50:00
adelady

amgnificent@gmail...
124.171.82.190

Just to be picky about images.  The Arctic map names the Chucki, Lapdev and Norvegian seas.  

Unless there's some consistent language other than English here, that should be Chukchi, Laptev and Norwegian Seas. 

2011-09-22 19:39:58
nealjking

nealjking@gmail...
84.151.33.164

Not Chuckycheese, Laptop, and NoWay seas?

2011-09-23 16:40:52
Agnostic

mikepope_9@hotmail...
118.208.155.206

Can you point me to an alternate depiction of the Arctic Basin/cobtinental shelf which has better spelling please?

2011-09-24 10:21:16
adelady

amgnificent@gmail...
124.171.82.190

http://nsidc.org/arcticmet/arctic_map.html      The names of the ocean regions are a bit faint and there are other features named more clearly.

I've checked Masie and Cryosphere Today and a couple of others all the 'ice-melt-followers' refer to.  They tend to have the map overlaid with colour patches  - but the names are attached only to the separate maps for the regions, not on the Arctic map itself. 

Bit disappointing.   Hard to notice that the material you think is really, really clear is actually quite hard to follow if you're new to it.  

There might be something simplified on the NSIDC site, but I've not spotted it so far.

2011-09-24 11:09:22
Daniel Bailey
Daniel Bailey
yooper49855@hotmail...
97.83.150.37

http://nordpil.com/static/images/arctic_topographic_map_full.jpg

Arctic

From Nordpil