Wednesday, July 24, 2013

Arctic Methane Release: "Economic Time Bomb"

On March 19, 2013, a number of experts came together for an Ecorys.com workshop, as part of a
Peter Wadhams Sc.D., Prof. of Ocean
Physics and head of the Polar Ocean
Physics group, Cambridge University.
study examining the impact of a 50-Gt release of methane from the melting permafrost at the East Siberian Arctic Shelf (ESAS) over different time periods, ranging from one to five decades.

Back in 2008, a study by Natalia Shakhova et al. considered release of up to 50 Gt of predicted amount of hydrate storage as highly possible for abrupt release at any time.

In order to estimate the cost of such a release, this new study used a more recent version of the model used in the renowned Stern Report. Findings of the study are published in the journal Nature. The conclusion is that such a release from the ESAS alone comes - in the absence of mitigating action - with a price tag of $60 trillion. By comparison, the size of the world economy in 2012 was about $70 trillion.

Such a methane pulse will "bring forward 15–35 years the average date at which the global mean temperature rise exceeds 2°C above pre-industrial levels", says the paper.

"The economic consequences will be distributed around the globe, but the modelling shows that about 80% of them will occur in the poorer economies of Africa, Asia and South America. The extra methane magnifies flooding of low-lying areas, extreme heat stress, droughts and storms."

"The total cost of Arctic change will be much higher," says the paper. To find out the actual cost, more feedbacks should be incorporated in the model, such as linking the extent of Arctic ice to increases in Arctic mean temperature. The full impacts of a warming Arctic include, for example, ocean acidification and altered ocean and atmospheric circulation. "Midlatitude economies such as those in Europe and the United States could be threatened, for example, by a suggested link between sea-ice retreat and the strength and position of the jet stream, bringing extreme winter and spring weather. Unusual positioning of the jet stream over the Atlantic is thought to have caused this year’s protracted cold spell in Europe."

Experts attending the workshop include: 
Peter Wadhams, Head of the Polar Ocean Physics Group at Univeristy of Cambridge.
Chris Hope,  reader in policy modelling at Judge Business School, University of Cambridge, and creator of the PAGE-models used for the Stern-report 
Carl Koopmans, Professor of Infrastructure and Economics, VU University, Amsterdam 
Henri de Groot, professor in Regional Economic Dynamics, VU University, Amsterdam 
Marcel Canoy, Professor at the School of Economics and Management, University of Tilburg
Gail Whiteman, Professor of sustainability, management and climate change at the Department of Business-Society Management, Erasmus University, Rotterdam 

Comments & Responses

Meanwhile [July 27, ed.], the piece in Nature has received wide news coverage, including a critique by Jason Samenow in the Washington Post. Peter Wadhams responds to some of the comments as follows:
Peter Wadhams: The 25 July post by Jason Samenow on the global economic impacts of methane emissions in the East Siberian Sea portrays the findings of our research as misleading, a statement with which I strongly disagree. Our work is based on a prediction of the magnitude and timing of methane emissions from the thawing of Arctic offshore permafrost by a scientist who has done extensive field work on this part of the ocean bed and is a globally recognized expert. We calculated the financial implications of these emissions for the world economy over a century and also considered the effect of the emissions on increasing overall global warming, obtaining a 0.6C figure by 2040. We rightly consider these to be substantial figures, which deserve wide circulation among climate scientists, and Nature and its referees agreed with us.

In our analysis we showed that the overall cost of a given volume of methane release is relatively insensitive to the rate of release or, within limits, its timing, BUT that the cost is roughly proportional to the overall volume of release. Thus, even if you worked with a different projection by a lesser qualified scientist than Shakhova, and revised down the figure and scale of the 60 trillion dollars accordingly, I suspect the cost will still be substantial – and that is one clear finding: The planetary cost of Arctic warming far outstrips any possible benefits to shipping or natural resource exploration.

In support of its skepticism about methane emissions the article quoted authors who wrote before the enormous retreat of summer Arctic sea ice and its oceanographic effects became so evident. The mechanism which is causing the observed mass of rising methane plumes in the East Siberian Sea is itself unprecedented and the scientists who dismissed the idea of extensive methane release in earlier research were simply not aware of the new mechanism that is causing it.

What is happening is that the summer sea ice now retreats so far, and for so long each summer, that there is a substantial ice-free season over the Siberian shelf, sufficient for solar irradiance to warm the surface water by a significant amount – up to 7C according to satellite data. That warming extends the 50 m or so to the seabed because we are dealing with only a polar surface water layer here (over the shelves the Arctic Ocean structure is one-layer rather than three layers) and the surface warming is mixed down by wave-induced mixing because the extensive open water permits large fetches. So long as some ice persisted on the shelf, the water mass was held to about 0C in summer because any further heat content in the water column was used for melting the ice underside. But once the ice disappears, as it has done, the temperature of the water can rise significantly, and the heat content reaching the seabed can melt the frozen sediments at a rate that was never before possible.

The 2008 US Climate Change Science Program report needs to be seen in this context. Equally, David Archer’s 2010 comment that “so far no one has seen or proposed a mechanism to make that (a catastrophic methane release) happen” was not informed by the Semiletov/Shakhova field experiments and the mechanism described above. Carolyn Rupple’s review of 2011 equally does not reflect awareness of this new mechanism.

Therefore I robustly defend our research and commentary, and hope that rather than dismiss the substantial risk such a methane release poses, the response might be to support more intensive research on this problem.
This is what Nathan Currier said in a comment at the Washington Post:
Nathan Currier: Earlier this year, a small piece of rock exploded over Russia, breaking some windows and causing minor injuries, yet shortly thereafter, a congressional panel was convened here in Washington, DC on the risks of significant asteroid impacts, and the panel, after being told they were about 1/20,000 for the year, was also told by the experts that billions will need to be spent to prevent a “possible catastrophe”. John Holdren, President Obama’s chief science advisor, commented, "The odds of a near-Earth object strike causing massive casualties and destruction of infrastructure are very small, but the potential consequences of such an event are so large it makes sense to takes the risk seriously." Holdren was right: in assessing a risk, it is a product of the probability and the magnitude that counts in the end. 
Nothing we do alters the risk of asteroid impacts, but our activities are profoundly altering the risks of unleashing powerful arctic carbon feedbacks. Like night and day with warming, where we don’t tend to notice that nighttime temperatures are increasing more rapidly than daytime ones, the scientific community’s assessments of risks tend to focus on those things which, by being more continuous, can have the daylight of quantitative analysis shone upon them more easily. But there is no question that the risks in the arctic that are rising most rapidly are the “nighttime” ones of abrupt changes. That is because there is already a 100% chance of increases in chronic emissions. Somewhat like larger and larger rocks hitting the earth, the risks of larger and larger methane pulses are certainly progressively smaller, but the important point here is that if we were to say conjecturally that in 1970 the risks of a 50Gt release might have been like the “city-killer” asteroid at 1/20,000, these risks now might have decreased by an order of magnitude. It is still not likely to happen now, with, let us speculate, a 1/2,000 risk, but because of the magnitude, as Holdren says, you should take this very seriously. Far more seriously, I might add, than a meteor striking the earth. Meanwhile, the leaked draft of the IPCC AR5 suggests that all arctic carbon feedbacks will be largely ignored in the report, even those that are more or less certain.

I would add that articles like this, characterizing the Nature commentary as “mischief” and “hype,” contribute to climate illiteracy in their own way, full of mischief without coming from a denialist perspective. There are too many errors here to elaborate them all. First, it makes a complete red herring of methane hydrate, quoting Ruppel on hydrate stability, etc. Let it be noted: 50Gt of methane is only about 2% of estimated Eastern Siberian Shelf (ESS) total carbon, and would only be 7% of the free gas reservoir that lies under the hydrate layer. There are many possible gas migration pathways for methane excursions, from pingo-like structures, fissures, the taliks appearing more and more throughout the permafrost layer, slope failure, sediment or mudslides around the Lena delta, an endogenous seismic event along the Gakkel ridge, etc. Thus, hydrate is really not even needed for a methane catastrophe scenario at the ESS. None of the quotes, moreover, about hydrate distinguish between the exceptional situation at the ESS of very shallow waters and the hydrates elsewhere around the world, which are indeed mostly quite secure.

Despite this, Hansen considers methane hydrate one of the three main coming tipping points in the climate system. The article quotes David Archer, a clear outlier on this issue, in that he doesn’t even believe the PETM warming (55 million years ago) was caused by methane hydrate release, which is the dominant paleoclimate theory, based on isotopic evidence. Meanwhile, it also quotes a paper claiming that there is no evidence for any major hydrate release at all over the last 100,000 years, clearly not something that Archer would agree with, as he himself has written an authoritative paper on the methane hydrate release of the Storrega landslide event (~8000 years ago).

At the group 1250 (1250now.org), we are focusing now on precisely the opposite, the subtler changes in surface-produced methane that are likely with further loss of sea ice, but it is shocking to see a response like this one to an issue of obvious importance.

To close, no one doubts that a 50Gt release of methane is “unlikely” right now if you consider 1/2,000, let’s say, unlikely. But as the thermal signal of anthropogenic warming propagates into the sediment below such shallow waters as at the ESS, and given that the ocean currents are not the same now as they have been during the paleoclimatic past, such that paleoclimate cannot ultimately be used to constrain and quantify the actual risk, it is clear that the risks, unlike those of asteroids, are growing.

But that was clearly NOT the point of the Nature commentary. The point of the commentary was to note that the impact would be very, very big. So, to go back to Holdren, it should be taken very seriously.
Also noteworthy is what Nathan Currier said in response to comments by Gavin Schmidt, quoted in the New York Times:
Gavin Schmidt: Threshold releases even 1/10 as large as postulated would be clear in ice cores. There is nothing there. In more recent past, there have been a number of times when Arctic (not necessarily globe) has been significantly warmer than today. Most recently, Early Holocene, which had significantly less summer sea ice than even 2012. Earlier, Eemian 125kyrs ago was significantly warmer.
Nathan Currier: I find Gavin Schmidt’s points here very thin. Let’s review them:

First, clearly no one is suggesting that during the 800,000 year period covered by ice cores there has been any such release. Further, David Archer, quoted in Revkin’s piece and a leading authority on such issues, has specifically discussed the possibility in a peer-reviewed paper (Archer, 2007) of fern diffusion allowing a Gt-scale release to escape detection in ice cores.

The problem with this argument, made repeatedly when this same issue erupted over a year ago, is that it is looking weaker than it did just a year ago: for example, we are learning that certain key ocean currents were significantly different during the Eemian than they are today – see http://phys.org/news/2012-06-climate-cold-arctic-eemian.html. And what counts in this argument is what the sea bottom conditions are, of course, not just the surface conditions. Schmidt is right that at times it was much warmer than today in the arctic, possibly 8C warmer, as we have seen from the Lake E work, but he forgets himself, and points to the early Holocene, although the area in question was a frozen piece of land at that time, not an underwater shelf, so that is purely irrelevant, as it took almost 4,000 years before the area in question became inundated.

But risks are growing significantly in the arctic by the year, and a 5Gt release, which would double the atmospheric burden, would result from less than 1% - about .7% - of estimated ESAS free gas below the hydrate layer being released, without any hydrate needing to be involved, which some kind of endogenous seismic event could conceivably set off, perhaps a sediment pile mud slide around the Lena mouth, for example. The point of the paper, lost in all of this, was just to say, this would cost us about $6 trillion.

The worst moment of Schmidt’s points, one which really merits censure, is to refer to all the research being done in the area (he clearly means Shakhova and Semiletov here) as “one off surveys.” Note that he isn’t even asking for better research to be done there, either. I personally find that quite unfortunate, even a bit embarrassing for someone who has built up a sterling reputation.

He (Schmidt) is certainly right that there is no recent example of CH4 being higher than the pre-industrial baseline, and that includes the “super-interglacials” from Lake E bores, but it is incredibly unwise to jump to the claim from that that we are not near dramatic releases without offering any evidence at all.

It is far better to go by the best peer-reviewed research about contemporary conditions on the ground than to speculate about the few generalities we can draw from the sketch of climates past we have put together for the last few million years, as valuable as that sketch is. There was at no time during that period anything like the 400ppm of CO2 in the atmosphere now, nor the many other GHGs levels we have boosted, nor the things that have no natural analogue like the CFCs, nor is there any analogue for the rate of change we have experienced, and so the sea level’s relationship to the atmospheric conditions has no analogue either, and we are also learning at the same time just how sensitive and variable key arctic ocean currents might be in this region.

All that said, Schmidt acknowledges that “potential for Arctic CH4 to have threshold behavior is real,” and I should also acknowledge that I agree that the 50Gt scenario is not likely at this time.
Let's also add a quote from an earlier post:
Sam Carana: Analysis of sediment cores collected in 2009 from under ice-covered Lake El'gygytgyn in the northeast Russian Arctic suggest that, last time the level of carbon dioxide in the atmosphere was about as high as it is today (roughly 3.5 to 2 million years ago), regional precipitation was three times higher and summer temperatures were about 15 to 16°C (59 to 61°F), or about 8°C (14.4°F) warmer than today.

As temperatures rose back in history, it is likely that a lot of methane will have vented from hydrates in the Arctic, yet without causing runaway warming. Why not? The rise in temperature then is likely to have taken place slowly over many years. While on occasion this may have caused large abrupt releases of methane, the additional methane from such releases could each time be broken down within decades, also because global methane levels in the atmosphere were much lower than today.

In conclusion, the situation today is much more threatening, particularly in the East Siberian Arctic Shelf (ESAS), as further described in other posts at the methane hydrates blog.
Also note the comments by Veli Albert Kallio, in an earlier post:
Albert Kallio: The problem with ice cores is that if there is too sudden methane surge, then the climate warms very rapidly. This then results the glacier surfaces melting away and the ice core begins to loose regressively surface data if there is too much methane in the air.

Because of this, there has been previous occurrences of high methane, and these were instrumental to bring the ice ages ice sheets to end (Euan Nisbet's Royal Society paper). The key to this is to look at some key anomalies and devise the right experiments to test the hypothesis for methane eruptions as the period to ice ages.

Thus, the current methane melting and 1800 ppm rise is nothing new except that there are no huge Pleistocene glaciers to cool the Arctic Ocean if methane goes to overdrive this time. In fact methane may have been many times higher than that but all surface ice kept melting away and staying regressive until cold water and ice from destabilised ice sheets stopped the supply of methane (it decays fast if supply is cut and temperatures fall back rapidly when seas rose).

The Laurentide Ice Sheet alone was equivalent of 25 Greenland Ice Sheets and the Weischelian and other sheets on top of that. So, the glaciers do not act the same way as fireman to extinguish methane. Runaway global warming is now possibility if the Arctic loses its methane holding capability due to warming.
Let's conclude the debate on the following note:
Sam Carana: Uncertainty does NOT constitute a valid argument to dismiss warnings about large abrupt methane releases in the Arctic. Instead, uncertainty calls for further research and for comprehensive and effective action, especially since so much is at stake and the dangers are getting larger each time the necessary action is delayed. 

References

- Vast costs of Arctic change, in Nature, vol 499, pp 401-403, July 25, 2013
by Gail Whiteman, Chris Hope and Peter Wadhams
http://www.nature.com/nature/journal/v499/n7459/full/499401a.html
http://www.nature.com/nature/journal/v499/n7459/pdf/499401a.pdf

- Ecorys studies economic valuation of climatic change impacts in the Arctic region
http://www.ecorys.com/news/ecorys-studies-economic-valuation-climatic-change-impacts-arctic-region

- Arctic time-bomb warning
in: Cambridge News, by Jennie Baker
http://www.cambridge-news.co.uk/Education/Universities/Arctic-time-bomb-warning-20130724123026.htm

- Anomalies of methane in the atmosphere over the East Siberian shelf: Is there any sign of methane leakage from shallow shelf hydrates?
N. Shakhova, I. Semiletov, A. Salyuk, D. Kosmach
http://www.cosis.net/abstracts/EGU2008/01526/EGU2008-A-01526.pdf

- Arctic methane release is an 'economic time bomb' - study
by Nafeez Ahmed
http://www.guardian.co.uk/environment/earth-insight/2013/jul/24/arctic-melt-methane-economy-time-bomb

- Ice-free Arctic in two years heralds methane catastrophe – scientist

Monday, July 22, 2013

Open Water at North Pole

Images from the North Pole Environmental Observatory are now showing large areas with open water at the North Pole. The image below is from Webcam 2, dated July 22, 2013.

[ click on image to enlarge ]
Furthermore, the number of spots with methane readings of over 1950 ppb appears to be rising. See related posts below to compare. Particularly worrying are the large number of spots over the Kara Sea. Also note the spot over Greenland in the top-left corner of the image below.

[ click on image to enlarge ]
The webcam shows water at the North Pole. Clearly, there still is some ice underneath the water, as is evident from the stakes that have been put into the ice to indicate the depth of surface water.

Surface water can build up as a result of melting as well as due to rain.

As the image on the right shows, the ice is getting very thin. In between the North Pole and Siberia, a wide corridor has developed where the ice is between zero and one meters thick.

Surface water could extend over this corridor, all the way to edge of the ice, in which case it effectively becomes part of open water.

The presence of water in areas close to the North Pole has been discussed in a number of earlier posts, such as this one.

The image below, from the Danish Meteorological Institute, gives some idea of the extent of the sea surface temperature anomalies that have been particularly prominent in the Kara Sea for some time.


Meanwhile, more water has appeared around Webcam2. Below are four later images, the top two images captured on July 24, 2013, the third one captured on July 25, 2013, while the bottom one was captured on July 26, 2013.






Note that the buoy associated with Webcam2, while originally positioned at the North Pole, has meanwhile moved away substantially from that location, as indicated by the image below, from http://imb.crrel.usace.army.mil/


Ice thickness image run July 26, valid July 27, 2013
for scale, see image further above. Buoy data up to July 28, 2013, buoy position: 84.87 N, 4.29 W.

On the animation above right, the track is shown against a sea ice thickness map, showing sea ice at webcam2's current position that is two meters thick.

So, while satellite images may indicate that the sea ice is still several meters thick in many locations, huge amounts of surface water may be present on top. The albedo of water is far lower than ice, so less sunlight is reflected back into space and a lot more heat is absorbed by the water, further accelerating the sea ice melt. This spells bad news for the remaining sea ice, since the melting season still has quite a bit of time to go.

Let's end with a video uploaded at youtube by climatecentral.org covering the period from April 16 to July 25, 2013.


Related posts

Open Water In Areas Around North Pole (posted June 22, 2013)
Watching methane over Arctic Ocean (posted July 20, 2013)
Heat, Fires and Methane (posted July 20, 2013)
High methane readings over Kara Sea (posted July 18, 2013)
Methanetracker (posted July 9, 2013)

Sunday, July 21, 2013

The Great Arctic Flush

By Paul Beckwith

A massive cyclone is forecast to develop in the Arctic, as shown on the image below, from the Naval Research Laboratory.

Within 2 weeks the Arctic Ocean will be completely transformed. The cyclone that appears 6 days out on both the US and European ten day forecasts will massacre the sea ice in what I call "The Great Arctic flush".

The image below is a forecast for Arctic sea ice speed and drift on July 27, 2013. More images, including animations, on Arctic sea ice can be viewed at http://www7320.nrlssc.navy.mil/hycomARC/arctic.html 


Last August, a massive cyclone formed over the Arctic Ocean and destroyed 800,000 square km of ice in about a week. The predicted cyclone looks to be as strong as the one in early August, 2012. Problem is, the ice is much weaker, thinner and fractured this year; including all the ice just north of the Canadian Arctic Archipelago that is 4 or 5 meters thick; this ice is mobile, broken, fractured ice piled up into ridges; it is not multiyear ice (MYI) at all.

Above image, from the Naval Research Laboratory is a prediction of ice speed and drift a week from now, showing the motion of the ice, the darker and redder the faster, the ice is being set in motion by the cyclone above. Since the Coriolis force flings things to the right, the ice is all sent to the outside of the rotation, into the warmer surrounding water as well as the Atlantic Ocean. The storm surge of a foot or two over the entire basin (highest near the cyclone eye) will draw in warm water from the Pacific via the Bering Strait and from the Atlantic via the Fram Strait. It will also mix the fresh water on the surface from melting ice with warmer saltier water from below. It will also generate lots of churning and grinding of the ice and waves several meters high. Warm and smoky air that is filled with ash and black carbon from burning fires in the far north will drop the albedo of the ice and increase the solar absorption. 

When I forecast zero sea ice at the end of the melt season this summer, I fully expected at least one or more of these massive cyclonic storms. Last year it occurred in early August, and lasted for about 8 days. In the rest of the melt season last year no other huge cyclone developed, although several small ones did. Perhaps the cyclone disturbed the ocean conditions enough to prevent subsequent ones occurring. We shall see this year...

edited screenshot from animation at weather-forecast.com


Paul Beckwith is a part-time professor with the laboratory for paleoclimatology and climatology, department of geography, University of Ottawa. He teaches second year climatology/meteorology. His PhD research topic is “Abrupt climate change in the past and present.” He holds an M.Sc. in laser physics and a B.Eng. in engineering physics and reached the rank of chess master in a previous life.

Saturday, July 20, 2013

Watching methane over Arctic Ocean



Above image, from Wunderground.com, shows high temperatures close to the Kara Sea, where methane readings over 1950 have been recorded for some time now (see earlier posts here and here).

The image below, from Foreca and kindly provided by Albert Kallio, shows that temperatures on parts of Kara Sea and surrounding coast hit 40 degrees Celsius (or 100°F) on July 20, 2013.


The image below, also from Foreca, shows the situation on July 21, 2013, at 1:00 pm.


The NOAA image below shows sea surface temperature anomalies for July 18, 2013.



The animation below shows methane readings for July 19, 2013. High readings over the Kara Sea persist, not surprisingly, while there's a worrying spot of methane over the East Siberian Sea and there are a number of high readings showing up over Greenland. The animation below is a 3.1 MB file, so it may take some time for it to fully load.