NOAA Arctic Sea Ice Report of April 2, 2014

Arctic sea ice at fifth lowest annual maximum

Arctic sea ice reached its annual maximum extent on March 21, after a brief surge in extent mid-month. Overall the 2014 Arctic maximum was the fifth lowest in the 1978 to 2014 record. Antarctic sea ice reached its annual minimum on February 23, and was the fourth highest Antarctic minimum in the satellite record. While this continues a strong pattern of greater-than-average sea ice extent in Antarctica for the past two years, Antarctic sea ice remains more variable year-to-year than the Arctic.

Overview of conditions

Figure 1. Arctic sea ice extent for March 2014 was 14.80 million square kilometers (5.70 million square miles). The magenta line shows the 1981 to 2010 median extent for that month. The black cross indicates the geographic North Pole. Sea Ice Index data. About the data.
Credit: National Snow and Ice Data Center
High-resolution image

Arctic sea ice extent for March 2014 averaged 14.80 million square kilometers (5.70 million square miles). This is 730,000 square kilometers (282,000 square miles) below the 1981 to 2010 average extent, and 330,000 square kilometers (127,000 square miles) above the record March monthly low, which happened in 2006. Extent remains slightly below average in the Barents Sea and the Sea of Okhotsk, but is at near-average levels elsewhere. Extent hovered around two standard deviations below the long-term average through February and early March. The middle of March by contrast saw a period of fairly rapid expansion, temporarily bringing extent to within about one standard deviation of the long-term average.

Conditions in context

Figure 2. The graph above shows Arctic sea ice extent as of April 1, 2014, along with daily ice extent data for four previous years. 2013 to 2014 is shown in blue, 2012 to 2013 in green, 2011 to 2012 in orange, 2010 to 2011 in brown, and 2009 to 2010 in purple. The 1981 to 2010 average is in dark gray. Sea Ice Index data.
Credit: National Snow and Ice Data Center
High-resolution image

In the Arctic, the maximum extent for the year is reached on average around March 9. However, the timing varies considerably from year to year. This winter the ice cover continued to expand until March 21, reaching 14.91 million square kilometers (5.76 million square miles), making it both the fifth lowest maximum and the fifth latest timing of the maximum since 1979. The latest timing of the maximum extent was on March 31, 2010 and the lowest maximum extent occurred in 2011 (14.63 million square kilometers or 5.65 million square miles).

The late-season surge in extent came as the Arctic Oscillation turned strongly positive the second week of March. This was associated with unusually low sea level pressure in the eastern Arctic and the northern North Atlantic. The pattern of surface winds helped to spread out the ice pack in the Barents Sea where the ice cover had been anomalously low all winter. Northeasterly winds also helped push the ice pack southwards in the Bering Sea, another site of persistently low extent earlier in the 2013 to 2014 Arctic winter. Air temperatures however remained unusually high throughout the Arctic during the second half of March, at 2 to 6 degrees Celsius (4 to 11 degrees Fahrenheit) above the 1981 to 2010 average.

March 2014 compared to previous years

Figure 3. Monthly March ice extent for 1979 to 2014 shows a decline of 2.6% per decade relative to the 1981 to 2010 average. Credit: National Snow and Ice Data Center. High-resolution image

Average ice extent for March 2014 was the fifth lowest for the month in the satellite record. Through 2014, the linear rate of decline for March ice extent is 2.6% per decade relative to the 1981 to 2010 average.

An increase in multiyear ice

Figure 4. Imagery from the European Advanced Scatterometer (ASCAT) show the distribution of multiyear ice compared to first year ice for March 28, 2013 (yellow line) and March 2, 2014 (blue line).
Credit: Advanced Scatterometer imagery courtesy NOAA NESDIS, analysis courtesy T. Wohlleben, Canadian Ice Service
High-resolution image

The extent of multiyear ice within the Arctic Ocean is distinctly greater than it was at the beginning of last winter. During the summer of 2013, a larger fraction of first-year ice survived compared to recent years. This ice has now become second-year ice. Additionally, the predominant recirculation of the multiyear ice pack within the Beaufort Gyre this winter and a reduced transport of multiyear ice through Fram Strait maintained the multiyear ice extent throughout the winter.

In Figure 4, Advanced Scatterometer (ASCAT) imagery reveals the distribution of multiyear ice compared to first year ice for March 28, 2013 (yellow line) and March 2, 2014 (blue line). The ASCAT sensor measures the radar–frequency reflection brightness of the sea ice at a few kilometers resolution. Sea ice radar reflectivity is sensitive to the roughness of the ice and the presence of saltwater droplets within newer ice (and, later in the season, the presence of surface melt). Thus older and more deformed multiyear ice appears white or light grey (more reflection), whereas younger, first-year ice looks dark grey and/or black.

Ice age tracking confirms large increase in multiyear ice

Figure 5. The map at top shows the ages of ice in the Arctic at the end of March 2014; the bottom graph shows how the percentage of ice in each age group has changed from 1983 to 2014.
Credit: NSIDC, Courtesy M. Tschudi, University of Colorado. High-resolution image

Satellite data on ice age reveal that multiyear ice within the Arctic basin increased from 2.25 to 3.17 million square kilometers (869,000 to 1,220,000 square miles) between the end of February in 2013 and 2014. This winter the multiyear ice makes up 43% of the icepack compared to only 30% in 2013. While this is a large increase, and may portend a more extensive September ice cover this year compared to last year, the fraction of the Arctic Ocean consisting of multiyear ice remains less than that at the beginning of the 2007 melt season (46%) when a large amount of the multiyear ice melted. The percentage of the Arctic Ocean consisting of ice at least five years or older remains at only 7%, half of what it was in February 2007. Moreover, a large area of the multiyear ice has drifted to the southern Beaufort Sea and East Siberian Sea (north of Alaska and the Lena River delta), where warm conditions are likely to exist later in the year.

Satellite Observations of Arctic Change

NSIDC now offers a new Web site, Satellite Observations of Arctic Change (SOAC)  with interactive maps of the Arctic based on NASA satellite and related data. The site allows you to explore how conditions in the Arctic have changed over time. Data sets include air temperature, water vapor, sea ice, snow cover, NDVI, soil freezing, and exposed snow and ice. Time periods vary by data set, but range from 1979 to 2013. You can animate a time series, zoom in or out, and view a bar graph of anomalies over time. Links to the source data and documentation are also included. Additional pages provide brief scientific discussion, and overviews of the scientific importance of these data. SOAC was developed with support from NASA Earth Sciences.

Reference

Stroeve, J., L. Hamilton, C. M. Bitz, and E. Blanchard-Wrigglesworth. 2014. Predicting September Sea Ice: Ensemble Skill of the SEARCH Sea Ice Outlook 2008–2013. Geophysical Research Letters, Accepted, doi: 10.1002/2014GL059388.

https://nsidc.org/arcticseaicenews/

NASA: Arctic Melt Season Lengthening 5 days per decade

from NASA, April 1, 2014

A new study by researchers from the National Snow and Ice Data Center (NSIDC) and NASA shows that the length of the melt season for Arctic sea ice is growing by several days each decade. An earlier start to the melt season is allowing the Arctic Ocean to absorb enough additional solar radiation in some places to melt as much as four feet of the Arctic ice cap’s thickness.

"The Arctic is warming and this is causing the melt season to last longer," said Julienne Stroeve, a senior scientist at NSIDC, Boulder and lead author of the new study, which has been accepted for publication in Geophysical Research Letters. "The lengthening of the melt season is allowing for more of the sun’s energy to get stored in the ocean and increase ice melt during the summer, overall weakening the sea ice cover."

A short video summarizes new findings about Arctic sea ice and warming oceans.  Play it!

Arctic sea ice has been in sharp decline during the last four decades. The sea ice cover is shrinking and thinning, making scientists think an ice-free Arctic Ocean during the summer might be reached this century. The seven lowest September sea ice extents in the satellite record have all occurred in the past seven years.

To study the evolution of sea ice melt onset and freeze-up dates from 1979 to the present day, Stroeve’s team used passive microwave data from NASA’s Nimbus-7 Scanning Multichannel Microwave Radiometer, and the Special Sensor Microwave/Imager and the Special Sensor Microwave Imager and Sounder carried onboard Defense Meteorological Satellite Program spacecraft. When ice and snow begin to melt, the presence of water causes spikes in the microwave radiation that the snow grains emit, which these sensors can detect.

Results show that although the melt season is lengthening at both ends, with an earlier melt onset in the spring and a later freeze-up in the fall, the predominant phenomenon extending the melting is the later start of the freeze season. Some areas, such as the Beaufort and Chukchi Seas, are freezing up between 6 and 11 days later per decade. Although melt onset variations are smaller, the timing of the beginning of the melt season has a larger impact on the amount of solar radiation absorbed by the ocean, because its timing coincides with when the sun is higher and brighter in the Arctic sky.

Despite large regional variations in the beginning and end of the melt season, the Arctic melt season has lengthened on average by 5 days per decade from 1979 to 2013.

Visit nasa.gov for more information about this research

Credits:

Production editor: Dr. Tony Phillips | Credit: Science@NASA

http://science.nasa.gov/science-news/science-at-nasa/2014/01apr_arcticice/

Cristian Suteanu: Arctic warming almost certainly man-made

via Alaska Dispatch, CBC News, Eye on the Arctic, November 28, 2013

A geography and environmental science professor at Saint Mary’s University in Halifax has been analyzing temperature data from the far north and says he’s almost certain the warming in the Arctic is caused by humans.

Cristian Suteanu has been looking at data from weather stations in Canada, Norway and Russia and said it’s almost improbable that the warming trend he’s seeing could be caused by natural variability.

“The temperatures on one day are not independent from the temperature of the next day or the next week, the next month and — it might sound surprising — the next year or the next decade. All the values are correlated with each other,” he told CBC’s Mainstreet.

“If you include that type of correlation in your analysis, the conclusion is that the warming, indeed, is more compelling. Even more importantly, it is even more improbable for the warming to occur naturally so we have to think of an anthropogenic source.”

Suteanu’s analysis of the temperature data will be published in a peer-reviewed journal called Pattern Recognition In Physics.

He said the scale of climate change and what’s happening to the planet is scary.

“You can’t avoid a feeling, a kind of shivering feeling,” said Suteanu.

“The overwhelming thing is that it’s going on on such a scale and the drivers behind that — if this is what we believe it is, anthropogenic — the drivers are so complex with the economy being so much a driver that the solutions seem to be really, really challenging. So that make things even more scary.”

This story is posted on Alaska Dispatch as part of Eye on the Arctic, a collaborative partnership between public and private circumpolar media organizations.

A Canadian professor in a new paper expresses rigorous doubts that the warming trend he’s seeing in the far north is caused by natural variability. Pictured is the Iñupiat village of Kivalina, Alaska. It sits on a narrow barrier island off the state's northwestern coast. A new stone seawall has helped curb erosion from winter storms, but it is only a stopgap, at some point in the near future the village will have to move. Dec 11, 2012Loren Holmes photo
http://www.alaskadispatch.com/article/20131128/researcher-arctic-warming-almost-certainly-man-made

Remarkable video and narration by scientist Ken Dunton on the "new" Arctic

Link:  https://www.youtube.com/watch?feature=player_embedded&v=L8IxxGWvM9s

Jennifer Francis Unchained, Breckenridge, January 2013

Nice that she uses Peter Sinclair's montage for about the first 3 minutes. Nothing you don't already know for the first 20 minutes, but she has done a really good job of using good graphics and explanations for a wider audience, including using a deck of cards.

But you might want to start at minute 20 because then she goes into the amount of warming over the Arctic with some good graphics showing how the heat varies by season and altitude -- very significant warming in the winter and at altitude in the winter.

http://www.youtube.com/watch?feature=player_embedded&v=xugAC7XGosM

UN: methane released from melting ice could push climate past tipping point

Doha conference is warned that climate models do not yet take account of methane in thawing permafrost 

by Fiona Harvey, environment correspondent, guardian.co.uk, November 27, 2013 

Frozen ground in Siberia. Permafrost covers nearly a quarter of the northern hemisphere. Photograph: Francis Latreille/Corbis

The United Nations sounded a stark warning on the threat to the climate from methane in the thawing permafrost as governments met for the second day of climate change negotiations in Doha, Qatar.

Thawing permafrost releases methane, a powerful greenhouse gas, but this has not yet been included in models of the future climate. Permafrost covers nearly a quarter of the northern hemisphere at present and is estimated to contain 1,700 gigatonnes of carbon – twice the amount currently in the atmosphere. As it thaws, it could push global warming past one of the key "tipping points" that scientists believe could lead to runaway climate change.

The UN Environment Programme (UNEP) called for the effect to be studied in detail by the Intergovernmental Panel on Climate Change (IPCC), the body of top climate scientists convened by the UN to provide governments with the most up-to-date and comprehensive knowledge on climate change. The next IPCC report will be published in several parts from next year.

Achim Steiner, executive director of UNEP, said: "Permafrost is one of the keys to the planet's future because it contains large stores of frozen organic matter that, if thawed and released into the atmosphere, would amplify current global warming and propel us to a warmer world. Its potential impact on the climate, ecosystems and infrastructure has been neglected for too long."

UNEP said warming permafrost could also "radically alter ecosystems and cause costly infrastructural damage due to increasingly unstable ground" and called for national monitoring systems to be put in place by countries with permafrost, including Russia, Canada, China and the US.

Most of the current permafrost formed during or since the last ice age and extends to depths of more than 700 metres in parts of northern Siberia and Canada. Permafrost consists of an active layer of up to two metres in thickness, which thaws each summer and refreezes each winter, and the permanently frozen soil beneath. As temperatures in theArctic are rising faster than elsewhere, this could increase the danger of permafrost melting. Warming permafrost could emit 43 to 135 gigatonnes of carbon dioxide equivalent by 2100 and 246 to 415 gigatonnes by 2200, according to the report, and emissions could start within the next few decades. Permafrost emissions could ultimately account for up to 39% of total emissions, according to the report.

UNEP's report came as governments argued over the future of the Kyoto protocol at the Doha climate talks. One of the main aims of the talks is an agreement to continue the protocol beyond the end of this year, when its current provisions and targets expire. But only the EU and a handful of other relatively small emitters, including Australia, Norway and Switzerland, have agreed.

Japan was once a strong defender of the protocol, taking pride in the fact that it was negotiated there. But the country has now abandoned it, in part because of fears that its neighbour, China, has taken a competitive advantage because it is not obliged to reduce its emissions.

Masahiko Horie, of the Japanese negotiating team, said: "Only developed countries are legally bound by the Kyoto protocol and their emissions are only 26% [of global emissions]. If we continue the same, only one quarter of the world is legally bound and three quarters of countries are not bound at all."

He said it was more important to Japan to formulate a new framework that would require action on emissions from developing as well as developed countries. At the talks, governments are expected to draw up a work plan that would set out how they will draw up such a new global agreement by 2015, coming into force in 2020.

But many developing countries want developed countries to continue with Kyoto beyond 2012 as part of any deal. Andre Correa do Lago, head of the Brazilian delegation, said: "If rich countries which have the financial means, have technology, have a stable population, already have a large middle class, think they cannot reduce [emissions] and work to fight climate change, how can they ever think that developing countries can do it? That is why the Kyoto protocol has to be kept alive. If we take it out, we have what people call the Wild West. You are not going get the [emissions] reductions necessary."

The talks will continue until the end of next week. [And as we all know -- they accomplished nothing.]

http://www.guardian.co.uk/environment/2012/nov/27/doha-climate-conference-un-methane

"Albedo evolution of seasonal Arctic sea ice," by Donald K. Perovich & Christopher Polashenski, GRL 39 (2012); doi: 10.1029/2012GL051432

Geophysical Research Letters 39 (2012) L08501; doi: 10.1029/2012GL051432

Albedo evolution of seasonal Arctic sea ice

Key Points

• During the melt season the albedo of seasonal ice is less than multiyear
• Seasonal ice absorbs and transmits more sunlight to ocean than multiyear
• Albedo evolution of seasonal sea ice has 7 phases

Donald K. Perovich (CRREL, ERDC, and the Thayer School of Engineering, Dartmouth College, Hanover, NH, U.S.A.) and Christopher Polashenski (CRREL, ERDC, Hanover, NH, U.S.A.)

Abstract

There is an ongoing shift in the Arctic sea ice cover from multiyear ice to seasonal ice. Here we examine the impact of this shift on sea ice albedo. Our analysis of observations from four years of field experiments indicates that seasonal ice undergoes an albedo evolution with seven phases; cold snow, melting snow, pond formation, pond drainage, pond evolution, open water, and freezeup. Once surface ice melt begins, seasonal ice albedos are consistently less than albedos for multiyear ice resulting in more solar heat absorbed in the ice and transmitted to the ocean. The shift from a multiyear to seasonal ice cover has significant implications for the heat and mass budget of the ice and for primary productivity in the upper ocean. There will be enhanced melting of the ice cover and an increase in the amount of sunlight available in the upper ocean.

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Figure 1 of 4

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Received 19 February 2012; accepted 23 March 2012; published 20 April 2012.

Perovich, D. K. and C. Polashenski (2012), Albedo evolution of seasonal Arctic sea ice, Geophys. Res. Lett., 39, L08501, doi:10.1029/2012GL051432.

http://www.agu.org/pubs/crossref/2012/2012GL051432.shtml

Peter Wadhams on the Catlan Arctic Survey

This is an excellent description of the need to measure the Arctic sea ice's thickness physically during the winter by using upward-looking radar of British submarines or manually drilling into it.  The thickness during the winter is the greatest factor for how much the extent will decline during the summer.
  https://www.youtube.com/watch?feature=endscreen&NR=1&v=q190H5MHmn4

UK MET Office keeps downplaying significance of events in the Arctic

by Sam Carana, Arctic News blog, September 17, 2012 One of the most respected datasets on Arctic sea ice volume is produced by the Pan-Arctic Ice Ocean Modeling and Assimilation System (PIOMAS, Zhang & Rothrock, 2003) developed at the Polar Science Center, Applied Physics Laboratory, University of Washington. The graph below shows PIOMAS data for annual minimum Arctic sea ice volume (black dots) with an exponential trend added (in red).

The Arctic Methane Emergency Group (AMEG), in a February 12, 2012, written submission to the U.K. Environmental Audit Committee, pointed at the graph:

. . summer volume [is] less than 30% of its value 20 years ago. The trend in volume is such that if one extrapolates the observed rate forward in time, by following an exponential trend line, one obtains a September near-disappearance of the ice by 2015.

The MET Office, in a March 8, 2012, written submission:

Climate models project the Arctic will become ice-free during summer at some point this century – though likely not before 2040. . . In September 2007, sea ice extent reached an all-time low, raising the question of whether the sea ice is likely to melt more quickly than has been projected. There is, however, no evidence to support claims that this represents an exponential acceleration in the decline. Indeed, modelling evidence suggests that Arctic sea ice loss would be broadly reversible if the underlying warming were reversed.

Professor Slingo, Chief Scientist, MET Office, elaborated on this in a March 14, 2012, oral submission:

Q114 Chair: . . when the Arctic will be ice free in summer. . . Professor Slingo: . . Our own model would say between 2040 and 2060 . . Q115 Chair: You would rule out an icefree summer by as early as 2015, for example? Professor Slingo: Yes we would . . . Q117 Chair: . . In terms of the modelling that you are using, does that cover . . . volume of ice? Professor Slingo: We run quite a sophisticated sea ice model. . . and we are looking forward now to the new measurements from CryoSat-2. Q118 Chair: . . evidence that we had suggested that the volume of ice had already declined by 75%, and that further decreases may cause an immediate collapse of ice cover. Professor Slingo: I wouldn’t [give credence to that]. We don’t know what the thickness of ice is across the whole Arctic with any confidence. . . I probably would [rule it out altogether] . . . to say we have lost 75% of the volume is inconsistent with our assessments.

Professor Laxon, director of Centre for Polar Observation and Modelling, where CryoSat-2 data is being analysed, in an August 24, 2012, written submission:

. . [analysis of] CryoSat-2 and ICESat data . . suggest a decrease in ice volume over the period 2003–12 at least as large as that simulated by PIOMAS, and possibly higher.

The Met Office, in an August 31, 2012, supplementary written submission:

The changes in observed sea-ice volume only extends [sic] over a few years and cannot in isolation be interpreted as representative of a long term trend. . . . The extrapolation of short-term trends in ice volume is not a reliable way to predict when the Arctic will be seasonally ice free as negative feedbacks and changing weather patterns may slow the rate of ice loss. . . it is worth noting that climate models can show a period of recovery in ice volume following periods of large ice volume loss.

For some curious reason, some people seek to downplay the significance of the events taking place in the Arctic, as well as the risk of methane releases. Here's more on that.

AMEG added, in its above February 12, 2012 written submission:

The catastrophic risk of global warming leading to very large emissions of methane from large Arctic carbon pools, especially from subsea methane hydrate, is documented in the 2007 IPCC assessment. By collaborating with others to protect the Arctic, a climate of cooperation can be engendered to protect the whole planet for the benefit of ourselves and future generations.

Professor Lenton, in a Feb 21, 2012, oral submission:

. . the Hadley Centre [has] permafrost in the latest state-of-the-art model . . . their best estimate is we may get 0.1°C of extra warming at the end of the century from the loss of methane from the northern high latitudes.

Professor Slingo, in the above March 14, 2012, oral submission:

Q126 Dr Whitehead:. . what sort of modelling factors may be accounted for by the possibility of tipping points or feedback attached to these? For example, the argument that follows very substantially from the extent of continental shelf that there is within the Arctic Basin and, therefore, the particular relationship that warming on that relatively shallow sea has on trapped methane-for example, the emergence of methane plumes in that continental shelf, apparently in quite an anomalous way-leading possibly to the idea that there may be either tipping points there or catastrophic feedback mechanisms there, which could then have other effects on things, such as more stabilised caps like the Greenland ice cap and so on. I rapidly collated all the possible catastrophe theories, but I mean how are those factored into the modelling process? Professor Slingo: . . we are not looking at catastrophic releases of methane. . . We don’t see catastrophic change in the Arctic that would lead to catastrophic releases of methane, or very large changes in the thermohaline circulation, within the next century. Our understanding of the various feedbacks-and it is a very complex system-both through observations and modelling, suggests that we won’t see those catastrophic changes, in terms of the physical system.

Note that the above are excerpts, to make things easier to read. For the full text, click in the respective links.

Below an update of the image, produced earlier this month, with recent volume data for 2012 added. Note that the value for 2012 may still have a substantial way to go down further before reaching its 2012 minimum.

The image below shows Arctic sea ice extent (total area of at least 15% ice concentration) for the last 7 years, compared to the average 1972-2011, as calculated by the Polar View team at the University of Bremen, Germany.

Below are written submissions to date to the Protecting the Arctic inquiry of the U.K.Environmental Audit Committee. Highlighted in yellow are submissions that are particularly relevant to points brought up by the Arctic Methane Emergency Group (AMEG), with links to videos and oral evidence added where available. 

01 Professor Peter Wadhams

02 The Arctic Methane Emergency Group   (add comments here)

• Parliament TV: watch 21 February 2012 meeting
• Oral evidence: read 21 February 2012 transcript   

03 The Remote Energy Security Collaborative

04 Client Earth and Environmental Protection UK

05 Greenpeace

06 The Natural Environment Research Council

07 The Centre for Ecology and Hydrology

08 Platform

09 WWF-UK

10 The Scottish Marine Institute

11 Professor Clive Archer

12 The International Polar Foundation UK

13 The Joint Nature Conservation Committee

14 The UK Government

15 Professor Klaus Dodds, University of London

16 Shell International Ltd

17 The International Fund for Animal Welfare

18 The Arctic Advisory Group

19 Greenpeace

20 Professor John Latham et al

21 The Geological Society

22 Prof S Salter

23 Cairn Energy PLC

24 The Met Office

• Parliament TV: watch 14 March 2012 meeting
• Oral corrected evidence: read 14 March 2012 transcript

25 Cairn Energy PLC, Supplementary

26 Professor Peter Wadhams, Supplementary   (add comments here)

27 Shell, Supplementary

28 Cairn Energy

29 Letter submitted by Lord Taylor of Holbeach, Parliamentary Under Secretary, Defra

30 Chair of the Sustainable Development Working Group of the Arctic Council

31 Supplementary written evidence from John Nissen, AMEG   (add comments here)

32 Henry Bellingham MP, Supplementary

33 Professor Seymour Laxon, Director, Centre for Polar Observation and Modelling

34 The Met Office, Supplementary

http://arctic-news.blogspot.com/2012/09/uk-met-office-keeps-downplaying-significance-of-events-in-the-arctic.html

Arctic expert predicts final collapse of sea ice within four years. As sea ice shrinks to record lows, Prof Peter Wadhams warns a 'global disaster' is now unfolding in northern latitudes

• by John Vidal, Arctic Sunrise, 81N, guardian.co.uk, September 17, 2012
  
  
  

Prof Peter Wadhams calls for “urgent” consideration of new ideas to reduce global temperatures. Photograph: John McConnico/AP

One of the world's leading ice experts has predicted the final collapse of Arctic sea ice in summer months within four years.

In what he calls a "global disaster" now unfolding in northern latitudes as the sea area that freezes and melts each year shrinks to its lowest extent ever recorded, Prof Peter Wadhams of Cambridge University calls for "urgent" consideration of new ideas to reduce global temperatures.

In an email to the Guardian he says: "Climate change is no longer something we can aim to do something about in a few decades' time, and that we must not only urgently reduce CO₂ emissions but must urgently examine other ways of slowing global warming, such as the various geoengineering ideas that have been put forward."

These include reflecting the sun's rays back into space, making clouds whiter and seeding the ocean with minerals to absorb more CO₂.

Wadhams has spent many years collecting ice thickness data from submarines passing below the arctic ocean. He predicted the imminent break-up of sea ice in summer months in 2007, when the previous lowest extent of 4.17 million square kilometres was set. This year, it has unexpectedly plunged a further 500,000 sq km to less than 3.5 million sq. km. "I have been predicting [the collapse of sea ice in summer months] for many years. The main cause is simply global warming: as the climate has warmed there has been less ice growth during the winter and more ice melt during the summer.

"At first this didn't [get] noticed; the summer ice limits slowly shrank back, at a rate which suggested that the ice would last another 50 years or so. But in the end the summer melt overtook the winter growth such that the entire ice sheet melts or breaks up during the summer months.

"This collapse, I predicted would occur in 2015-2016, at which time the summer Arctic (August to September) would become ice-free. The final collapse towards that state is now happening and will probably be complete by those dates."

Wadhams says the implications are "terrible." "The positives are increased possibility of Arctic transport, increased access to Arctic offshore oil and gas resources. The main negative is an acceleration of global warming."

"As the sea ice retreats in summer the ocean warms up (to 7 C in 2011) and this warms the seabed too. The continental shelves of the Arctic are composed of offshore permafrost, frozen sediment left over from the last ice age. As the water warms the permafrost melts and releases huge quantities of trapped methane, a very powerful greenhouse gas so this will give a big boost to global warming."

http://www.guardian.co.uk/environment/2012/sep/17/arctic-collapse-sea-ice

Readers, I am adding a graph from Sam Carana's Arctic News blog:
http://arctic-news.blogspot.com/2012/09/uk-met-office-keeps-downplaying-significance-of-events-in-the-arctic.html

Below an update of the image, produced earlier this month, with recent volume data for 2012 added. Note that the value for 2012 may still have a substantial way to go down further before reaching its 2012 minimum.