Arctic sea ice volume: The death spiral continues

One-year-old ice in Beaufort Sea now a foot thinner than in 2009

In November, Rear Admiral David Titley, the Oceanographer of the Navy, testified that  “the volume of ice as of last September has never been lower”¦in the last several thousand years.” Titley, who is also the Director of Navy’s Task Force Climate Change, said he has told the Chief of Naval Operations that “we expect to see four weeks of basically ice free conditions in the mid to late 2030s.”

Wieslaw Maslowski of the Naval Postgraduate School has “projected a (virtually) ice-free fall by 2016 (+/- 3 yrs).” Contrary to some reporting, that projection has been unchanged for years, though Maslowski is in the process of creating a more sophisticated model that he expects “will improve prediction of sea ice melt,” as he explained to me recently.

Until then, we have some new observational data of Canadian sea ice thickness and this remarkable figure of sea ice volume since 1979 from Neven’s Arctic Sea Ice Blog, based on data from the University of Washington’s Polar Science Center [click to enlarge]:


Arctic sea ice volume by month in cubic kilometers (with simple quadratic trend lines projecting to zero volume, details here).  The bottom (red) line is September volume.

Compare this to Maslowski’s March 2010 PowerPoint:

Maslowski SMALL

Maslowski’s linear projection is based on a combined model and data trendline focusing on ice volume.  By “ice-free,” Maslowski tells me he means more than an 80% drop from the 1979-2000 summer volume baseline of ~200,00 km^3.  Some sea ice above Greenland and Eastern Canada may survive into the 2020s (as the inset in his figure shows), but the Arctic as we’ve known it will be gone.  And irreversibly so — again contrary to some misreporting (see “Polar bear, Arctic sea ice all-but doomed: Misleading Nature cover story misleads the media, public“).

Last month, Maslowski emailed me “the sea ice behaviour during the 2009-2011 does not provide arguments to change this projection based on volume trend.”  But he also noted, “There is some indication from the QuickScat data that 2nd and 3rd year ice has increased somewhat in the past couple of years which may imply not so linear decline of arctic ice volume.”

Relatedly, this week, the research aircraft Polar 5 of the Alfred Wegener Institute for Polar and Marine Research “returned from Spring Measurements in the High Arctic” with these observations:

One of the key aspects of the expedition were large-scale sea ice thickness measurements in the inner Arctic, in which researchers of the Alfred Wegener Institute and the University of Alberta cooperated closely. For this purpose they used a four metre long electromagnetic ice thickness sensor, called EM Bird. The Polar 5 towed the sensor on an 80 metre long rope at a height of 15 metres above the ice surface for the surveys.

A preliminary evaluation of the measurement results shows that one-year-old sea ice in the Beaufort Sea (north of Canada/Alaska) is about 20-30 centimetres thinner this year than in the two previous years. In 2009 the ice thickness was 1.7 metres on average, in 2010 1.6 metres and in 2011 around 1.4 metres. “I expect that this thin one-year-old sea ice will not survive the melting period in summer,” Dr. Stefan Hendricks assesses the situation.

So we may have some more 2nd and 3rd year ice, but at least some of the Arctic ice is thinner than before.

Whether the Arctic goes virtually ice-free by 2019 — or whether it takes another decade — the outcome is now all but inescapable.  In September, National Snow and Ice Data Center’s director Mark Serreze said, The volume of ice left in the Arctic likely reached the lowest ever level this month” and “I stand by my previous statements that the Arctic summer sea ice cover is in a death spiral. It’s not going to recover.”

The death spiral is real “” and quite consequential for humanity.  in September, a first-of-its-kind analysis by an international team of 18 top scientists found “less ice covers the Arctic today than at any time in recent geologic history” and this ice loss isunexplainable by any of the known natural variabilities.”  They concluded:

Reviewed geological data indicate that the history of Arctic sea ice is closely linked with climate changes driven primarily by greenhouse and orbital forcings and associated feedbacks. This link is reflected in the persistence of the Arctic amplification, where fast feedbacks are largely controlled by sea-ice conditions.

A 2008 study led by David Lawrence of the National Center for Atmospheric Research (NCAR) concluded (see “Tundra 4: Permafrost loss linked to Arctic sea ice loss“):

We find that simulated western Arctic land warming trends during rapid sea ice loss are 3.5 times greater than secular 21st century climate-change trends. The accelerated warming signal penetrates up to 1500 km inland”¦.

In other words, if it continues, the recent trend in sea ice loss may triple overall Arctic warming, causing large emissions in carbon dioxide and methane from the tundra this century (for a review of recent literature on the tundra, see “Science stunner: Vast East Siberian Arctic Shelf methane stores destabilizing and venting; NSF issues world a wake-up call: “Release of even a fraction of the methane stored in the shelf could trigger abrupt climate warming”).  Indeed, Lawrence himself said, “Our study suggests that, if sea-ice continues to contract rapidly over the next several years, Arctic land warming and permafrost thaw are likely to accelerate.”

A February study by NSIDC with conservative assumptions concluded, “Thawing permafrost feedback will turn Arctic from carbon sink to source in the 2020s, releasing 100 billion tons of carbon by 2100.”  The paleoclimate record is not reassuring (see “The methane hydrate feedback revisited“)

The time to act is a while ago, but now is better than later.

h/t Grinzo who notes “The month with the lowest volume, September, has declined from roughly 18,000 km3 to around 4,000 km3….  Remember that 1 km3 of ice weighs 1 billion metric tons.”

National Snow and Ice Data Center

60 Responses to Arctic sea ice volume: The death spiral continues

  1. Ethan Von Braun says:

    Pretty soon this will be a travel destination to catch a tan and play on the beach. Maybe the repuklicans should think about this before pushing for more drilling.

  2. dorlomin says:

    Thinner ice means it will take less energy to melt it out and till it turns from a surface that is very reflective to a very absorbant of light energy. Open ocean can accumulate huge amounts energy through the long endless days of summer when it does not really have a night.

  3. Mark Shapiro says:

    This graph stuns.

    A couple simple caveats:

    1) The volume data from PSC’s PIOMAS is estimated, that is, modeled, and thus has unknown error bars.
    2) The quadratic trend lines are only that — trends, not predictions.

    That said, this is about the most dramatic, terrifying graph of climate data that I have ever seen. And note that all twelve lines are actually below the quadratic trends.

    Thanks to UW’s PSC folks and others for bringing this data to light.

  4. Mark Shapiro says:

    One other important comparison — hasn’t IPCC been projecting that the Arctic won’t be ice-free until about 2090 or so?

    Watch this space.

  5. Adam R. says:

    Ominous stuff, Joe, but surely the “Arctic sea ice volume by month in km3 with simple quadratic trend lines” graph does not mean anyone thinks the Arctic Ocean will be ice-free in February of 2033.

  6. Gosh, my eyes see a zero volume about 2019.

    A completely ice free summer is a big benchmark.

  7. Wonhyo says:

    The quadratic trend shows late summer sea ice smoothly declining to zero by 2016. I expect the process won’t be that smooth. My adjusted estimate for seasonally ice-free arctic is 2013+/-3 yrs.

  8. Mark Shapiro says:

    Adam R — I certainly don’t expect that the Arctic Ocean will be ice-free in February 2033, but I am watching for it to be virtually ice-free in September 2017, and then ice-free longer and longer every year or so. That will be plenty dramatic.

    We can watch it melt in stunning full color, courtesy of NASA’s Aqua and Terra satellite images, here:

    Caution: these images can be time-consuming.

  9. Heraclitus says:

    I didn’t think there was anything that could still do it, but when I first saw that graph at Neven’s place I had a real stomach lurch.

  10. GFW says:

    My personal guess is that *something* will slow down the loss rate from those quadratic fits, even if it’s just the simple fact that as it retreats, it retreats to higher latitudes where the melt season is shorter and the freeze season longer. Nonetheless, I’d currently believe an “effectively ice free” summer minimum by 2020+-3, which is far sooner than GCMs or the IPCC have predicted.

    Gonna be a really interesting rest of this decade.

  11. Neven says:

    Thanks for the link, Joe. If you weren’t so busy I’d ask you to write a guest post, because of all climate bloggers your grasp of the situation in the Arctic is the best and most comprehensive. And the Arctic is the number 1 AGW frontline. This is the in your face area that will very probably soon be impossible to deny (if it isn’t already).

    I keep repeating over at my blog: we need CryoSat-2 data fast. NASA, ESA and AWI (the Alfred Wegener Institute) have done a tremendous job this spring with various operations to help calibrate the satellite data. I really hope we get some preliminary results by the end of this melting season.

    The graph above is based on the PIOMAS model data. There’s still a chance that there is more volume in reality. I hope this is so, even if it wouldn’t change much except the timeline.

    [JR: It is certainly true there could be more volume. There could also be less — especially in the late summer, early fall, as that is when the rotten ice becomes particularly hard to distinguish from ‘healthy’ ice remotely.]

  12. Adam R. says:

    @8 Mark Shapiro

    Adam R — I certainly don’t expect that the Arctic Ocean will be ice-free in February 2033,

    Of course not. The graph is not a prediction, as you said, but I think Joe might make that more clear.

    …but I am watching for it to be virtually ice-free in September 2017,

    I agree. It will be amusing to see how the likes of Watts attempt to wiggle out of that one.

  13. Patrick Mazza says:

    Get ready for your summer sail to circumnavigate the Arctic Ocean. After two expeditions did it last year, could become a regular thing. We didn’t find the Northwest Passage. We made it.

    The Second Coming headlines that should be filling every newspaper and news broadcast in the world should be the Arctic ice death spiral and the implications for leakage from tundra, peats and hydrates. This is the MOST SERIOUS EVENT that is taking place on this planet right now, bar none.

    I was speaking to a UW climate scientist friend the other day to probe to what degree the wild weather we’ve seen over the past winter and spring in the Northern Hemisphere is tied to changing conditions in the Arctic. He said the Arctic Oscillation used to seal off the Arctic air with its wind gyre circling the pole. But the warming is mixing the air up more, and so more Arctic air is making its way southward. That ties to a lot of the wild weather.

    The new normal? We’ll see. I would like to learn much, much more about anticipated effects of Arctic warming and a blue water summer ocean on weather in North America and Europe.

  14. Mike Roddy says:

    “Not much has been going on in the sea ice arena”- the intrepid Anthony Watts on his blog today. He then goes on to forecast a “media frenzy” over sea ice.

    Any time Arctic ice news gets too troubling, we can always go to Anthony and find out that everything’s OK. Why not? There are plenty of people around who say that smoking is good for you, that evolution is a wild theory, etc. The difference is that Watts’ crackpot audience is bigger.

    I’d throw in a snarky comment over at WUWT, but have been banned there.

  15. dorlomin says:

    Worth pointing out the ‘melt’ conditions have been sub optimal over the past few weeks, little in the way of export of ice out of the region and temperatures slightly below average.

    Yet we are at or near a record low for this time of the year on just about all of the main datasets (JAXA, Cryosphere today, Artic ROOS, NSIDC etc)

    But then again nature has a habit of not doing what you expect, especially in the arctic. We can guess at what might happen, but there is no way to be sure what will happen. My guess is we will challange the 2007 minimum this year, but who knows, lots of cloud and little ice export and we may not even beat 2006.

  16. dhogaza says:

    Mike Roddy – in Anthony’s defense (mark down this date in the history books, this may be the first and might be the last time I defend him), he says:

    “we are in that time of year when all of the years converge into a tighter grouping”

    It’s true. It’s the time of year when arctic sea ice fans begin speculating about what will happen in a few weeks and later, when the melt season is reaching its peak and when sea ice extent for various years begin to depart. At the moment it’s like we’re watching a long distance race where the best runners are bunched in a pack … before long, we’ll see that 2010 started an early kick towards the finish line but, as it turned out, fell short of the record minimum set by 2007.

    And he talks about the fact that soon people will be submitting their september 2011 minimum predictions.

    Now, Anthony likes to argue that “nothing is going on” regarding trends, as well, that the Skate surfaced at an ice-free north pole in the 1950s (false), etc etc etc. On that, we can freely, frequently, and flamedly call baloney.

  17. Villabolo says:

    @14, Mike Roddy:

    “I’d throw in a snarky comment over at WUWT, but have been banned there.

    It’s as easy as changing your IP address. It helped me get into WUWT after being banned twice.

    If you don’t know how to change it, here’s the easiest way:

    1. Close all windows.

    2. Go to Start, then Run and type cmd, then select OK.

    3. Type ipconfig/release and press Enter.

    4. Once the prompt returns, type ipconfig/renew, then hit Enter.

    5. Finally, type exit and then press Enter to close the window.

    6. You’re done. You have a new IP address.

    I look forward to seeing your snarky comment at WUWT.

  18. Sue in NH says:

    Can someone explain to this non-statistician, why the quadratic modeling works for September sea ice, but is not valid for winter sea ice?


  19. paulm says:

    Looking like it’s going to be between 2012-2014. Certainly below 2020.
    Neven, arctic is definitely the front line, butt also now is the extreme weather. The events of the last 18mths, cumulating with what’s happening in the us now has slapped most people in the face.

    I have mates would are coming round to reality fast due to this.

  20. Steve L says:

    #10 GFW makes a good point. There’s also the issue that ice coverage is declining fastest well after the summer solstice, such that radiation absorption before Sept 22 is offset to some (potentially increasing) degree by heat loss afterward (since the ice isn’t there as insulation).

    This natural feedback (low ice in summer means more heating, low ice in winter means more heat loss to the atmosphere and space) got me thinking — perhaps there is some way to promote more open ocean in the winter. If it were possible to pile up the ice, a smaller area would be thicker come summer (and have a greater chance of surviving the melt season) whilst the greater open area promoted heat loss from the ocean.

  21. Steve Bloom says:

    Re #19: Sue, some ice will persist in the winter darkness until such time as the water warms enough to keep it from forming. That will likely take decades, probably many decades, although substantial additional encroachment of warm water from lower latitudes would speed things up. The exact timing of any of this is of course impossible to know, and of course the process is greatly dependent on how much more we heat up the entire climate system.

  22. Villabolo says:

    My S.W.A.G is, 2018-2021 based on the following definition:

    The Arctic Ocean being ice free in the summer, initially for a few days; then progressing to weeks and months in subsequent years. This will be with the exception of a band of ice, in the colder, shallower ocean, over the continental shelf; located north of Alaska, Canada and Greenland.

  23. Sue in NH says:

    Re Steve #22 Thanks for that. I understand the reality of why there should still be winter sea ice for some time. I’m having trouble with the graph though.
    If the Quadratic regression works for September, but not for winter months… where does the split happen?

    Related question, how to explain to my students why the September curve is valid, but the winter months are not?

  24. Ed Hummel says:

    I agree with all those who said that the graph is a stomach turner and says more about what’s happening and where we’re heading than just about anything Joe has posted in the past year. I would also add that I’ve never as wimpy a jet stream pattern over North America this early in the season as I’ve been seeing the last few weeks. And as I pointed out in a previous post, wimpy jet streams leads to persistent blocks which lead to parallel drought and flood conditions. I don’t think we’ve seen the end of our troubles in the US this year by any means, and with the Arctic warming apparently accelerating as reflected in that ice volume graph, I don’t think that “normal” is going to have any meaning in the future any more.

  25. David Gould says:

    Sue in NH,

    From a mathematical perspective, when the extent minimum drops to zero, the winter curves change to linear declines rather than quadratic ones. You can model this in excel. I am not sure of the physical reason for this as opposed to the mathematical one, however …

    If you would like me to send you an excel document that shows this, let me know.

  26. David Gould says:

    (I should note that this mathematical model is only valid if you look at the Arctic in a particular way)

  27. Artful Dodger says:

    Adam R, Steve Bloom, Sue in NH:

    Don’t be too sure about your common sense assumptions about Arctic Sea-ice in April 2033 (February is NOT the sea-ice max). Read Eisenman and Wettlaufer (2008) “Nonlinear threshold behavior during the loss of Arctic sea ice”, available freely from Proceedings of the National Academy of Science of the United States. The paper says in part:

    “Under a moderate warming (ΔF0 = 15 Wm−2), modeled sea-ice thickness varies seasonally between 0.9 and 2.2 m. Further warming (ΔF0 = 20 Wm−2) causes the September ice cover to disappear, and the system undergoes a smooth transition to seasonally ice-free conditions. When the model is further warmed (ΔF0 = 23 Wm−2), a saddle-node bifurcation occurs, and the wintertime sea ice cover abruptly disappears in an irreversible process.”

    Figure 3 Bifurcation diagram for the full nonlinear model

    “ΔF0” means the “Change in Climate Forcings relative to time Zero” in units of Watts per square meter. This means that after the first Sea ice free September, Climate forcings need to increase by a further 3 watts per square meter until the Arctic Sea Ice disappears permanently, including during Winter.

    The scarey part is that this is PERMANENT. Figure 3 shows that once the Arctic Ocean is perennially sea-ice free, then Climate forcings can fall all the way back to 17 W/m^2 before ANY sea-ice begins to reform.

    With our current C02 trajectory, and the looming Methane clathrate gun, this could easily occur by 2033. There is no going back once it happens, not in a thousand years or more.

  28. Dickensian American says:

    Stunning stuff. The multi year trend on May-July is disturbingly steep. Makes sense too with the significant change in slope on this year’s ice extent starting mid April through now in May.

    By mid June we may be 7-10 days ahead of the retreat of extent in the record breaking 2007 melt season. And it all lines up with the information in this post.

  29. Aaron Lewis says:

    #22 Steve,
    Once there is a substantial ice free area, storm mixing will increase the salinity at the surface, causing the the freezing point to drop. After that, it will be much harder to reform sea ice.

  30. Barry says:

    The article ends with a note from Lou Grinzo that says September is missing 14,000 billion tonnes of sea ice. Humanity has released around 1,300 billion tonnes of CO2. That is a ratio of about 10 tonnes of sea ice removed for every 1 tonne of CO2 emitted.

    Interestingly that is about the same ratio for land ice. Each year about 10 tonnes of land ice disappears for every one tonne of CO2 emitted that year.

    To top it off, less than half the CO2 we have emitted stays in the air.

    CO2 is just an amazing heat trapping beast.

    Stuff like this really drives home Caldiera’s calculation that each molecule of CO2 traps 100,000 times more heat than is released when it was created by burning the fossil fuel.

    If all the eventual trapped heat from the CO2 the average American releases were released along with that CO2 it would be equivalent to a burning oil well.

    Remember when Hussein lit the Kuwaiti oil field on fire? Each American is releasing CO2 potential heat at the rate of one of those infernos — 24/7/365

    For decades now.

    Millions are burning in Manhattan alone. A third of a billion across USA. Four in the backyard of the average family home. Quite a bar-be-que.

    When I think about the physical reality of all that heat it no longer seems so shocking how fast the weather has gotten weird.

  31. MARodger says:

    Re Comments #19 & #24. Is somebody saying a quadratic model doesn’t fit the winter months? Likely the data isn’t bendy enough for a decent segment of a quadratic cirve. It also has a lot more way to project before it hits the zero point.

    My own bugbear regarding PIOMAS remains the continued reluctance to plot Total Arctic Sea Ice volumes as per Maslowski’s Powerpoint above (which stops in 2005). The usual PIOMAS anomaly graph slopes increasingly down in a very dramatic manner but the graph shows no zero point. My attempts at a Total Arctic Sea Ice volume graph resides on the Facebook link below (where individual image links are no linger open which is why you get the whole album)plotted up to end of 2010. PIOMAS for May 2011 looks pretty much equal to May 2010. And PIOMAS is predictive not measured. But in the post above we hear of thickness measurements showing significat reductions from last year & also Ice Extent is down on last year. PIOMAS may be predicting values higher or lower than reality but the situation remains very worrying.
    Some graphs including a Total Volume graph based on PIOMAS graphs can be viewed at

  32. Bob Schildan says:

    I doubt sea ice will ever completely disappear in the winter months. Remember folks, the arctic gets down to -30 thru -60 C each winter… in order for the arctic to not refreeze in winter, it would require an equivalent amount of warming. The world then would have much, MUCH bigger issues than an ice-free arctic in winter, like 50 C heat waves, for example, commonplace throughout temperate latitudes.

  33. FrankD says:

    Long time reader, first time commenter…

    MARodger – I feel your pain, although PSC *have* made some of their data available (have a rummage at Neven’s blog). The data for this was developed from the public posted graphs – by smashing together data interpolated from the PSC Anomaly Graph and their graph of mid-month mean volume. A crude process, but it was initially intended only to satisfy my own curiosity (which it did). For what its worth, a different approach to retrieving the data from the same source material produced very similar results (again, this is all discussed at Neven’s) so I’m confident its not too bad.

    Some here will recall that a certain vocal blogger on Arctic ice found out the hard way that you need to be careful picking your end points when determining trends in periodic data. Now, I’m nobodies idea of a mathematician, but I figured that presenting each month seperately avoids that problem. However, for anyone who wants to present it as a single curve, the source data for my monthly curves is posted here: (seems to be having server problems at the time of posting.)

    Mark Shapiro – thanks for being so quick here and at Lou Grinzo’s to clarify what this is *not* – what I would have said, but better.

    [JR: Yes, server problems last night — else I would have linked.]

  34. Crandles says:


    My uneducated answer would be that curve extrapolation is always a dodgy exercise as there are always other curves that look similar over the range with data but then diverve afterwards (possibly rapidly). It should then be obvious that it is important to make sure you are using a sensible curve shape.

    Larry Hamilton has been fitting Gompertz curves to the data which make more sense for extrapolation as going back prior to 1979 you can be sure the Gompertz fits are going to be better and going forward it prevents predictions of negative volume.

    The quadratic extrapolation is not sensible for winter as we know less ice in winter means less insulation and more heat loss. This effect will become more important as the winter ice reduces. For summer months, it is much more sensible to suggest that albedo feedback will continue to overwelm the winter insulation effect and the quadratic shape is more able to continue.

    >”Where does the split happen”? That is simple to answer in 2 words – everywhere slowly.

  35. Tony O'Brien says:

    Twenty years to winter navigability by non icebreakers?

  36. Jakob Wranne says:

    Margaret Chan, General Secretary at WHO, said at the World Health Day in 7 april 2008:

    “Man is threatened as a species by the Climate Crisis. The Climate Crisis is therefore the most important question regarding health, this century.”

    She continued “The effects on health has not gotten the awareness needed, in the climate debate.”

    She also said that “the medical sector has to react, use their voices and act BOTH to stop the warming AND to prepare society for the catastrophes coming.”

  37. Jakob Wranne says:

    We have this pedagogic problem:

    To oneself it’s hard and frightening to imagine the consequenses of the Climate Crisis. And it’s even harder and more frightening to explain it to a fellow human.

    How do I tell someone that is unprepared, that the rains are going to get worse, that the food will be to expensive, that his kids will live in turmoil and probably die an nasty and early death – because he my fellow human lives a pleasant life with a car, tv and vacations at the other side of the planet?

  38. Jakob Wranne says:

    Later on, we will face another pedagogic problem:

    When we have solved this crisis, we will for eons keep our hands from coal, fossils and methane. And every kind of green house gas.

    How do we keep that knowledge living? For eons?

    How do we keep that motivation up? For eons?

  39. Jakob Wranne says:

    I trust we can do it.

  40. Dorothy says:

    Has anyone done modeling for just how bad it will be when the entire, or nearly entire, surface of the Arctic ice has melted? It would be useful to get an idea of the effect this will have on the Earth’s climate if the melt were to last for, say, a week, a month or longer.

    When will the Arctic sea ice melt become catastrophic, if it hasn’t already?

    I’d really like to get some feed back on this from you all.

  41. John L. McCormick says:

    RE # 41

    Dorothy, you ask a very huge question.

    I do not have time right now to offer links so do a search on Asian monsoon AND Arctic ice melt back.

    You will find a great deal of discussion about possible connections between melt back and interference with timing and intensity of the monsoons.

    When you find good info, come back to CP and tell us what you have learned.

    John McCormick

  42. Ed Hummel says:

    Bob Shilden at #33, what makes you think that the Arctic will be seeing a continuation of -30 to -60F temperatures with a nearly ice free ocean? The only places in the polar latitudes that will have any abiltiy to cool off to sub zero levels and stay there for any length of time without an ice covered Ocean in winter will be the interior of north central Canada near the Arctic Archipelago as well as parts of interior Siberia east of the Russian heartland. And even those regions won’t stay cold for very long they way they can now because they’ll repeatedly be assaulted by relative warm surges from evey direction. That’s one of the reasons why people are becoming so alarmed about ice loss over the Arctic Ocean; it would totally screw up all the circulation patterns that we’re used to seeing for most of the year.

  43. #41 Dorothy There is some evidence that the Arctic melt is changing weather patterns. I covered some of the first research on this last year:

    “Arctic Melt Down Is Bringing Harder Winters”

    Joe has also written about this.

  44. David Miller says:

    Good article Joe, but I think you have a typo. ‘~200,000’ km^3 should surely be 20,000 ?

    I suppose it’s really too soon to tell what the effects of less ice will be. My guess is that adding that much energy to the atmosphere will have a major influence on weather. Indeed it’s already been blamed for a number of anomalies like the Russian heat wave last summer. I’d like to see the results of real research for this.

  45. Bob Schildan says:

    Ed Hummel at #43, the fact that zero solar energy imput will be hitting the north pole for 6 months straight will always cause sea ice to form. The fact that water acts as a huge reservoir of heat already goes into play in the arctic. The north pole is much, much warmer than the south pole, due to the fact that it is located in the ocean as opposed to an elevated continent. January average temperatures at the north pole average around -34 C (-29 F) (wikipedia). If the Arctic Ocean stayed ice-free until some arbitrary time, like November, the amount of heat radiated by the ocean would eventually be enough so that the water temperature dropped sufficiently to refreeze each winter, due to Polar Night. It would require upwards of -30 C warming in the arctic for ice to not reform in winter.

  46. Artful Dodger says:

    Bob Schildan #46. Explain why the Paleoclimate record shows clearly that the Arctic Ocean has been perennially sea-ice free in the past, under a warmer climate.

  47. adelady says:

    Bob Schildan, did you see how long it took, last winter, for Hudson Bay to freeze over? You only have to extend that event a little further north in a few more places, and a couple more weeks past New Year’s Day and the whole freeze-melt thing is completely disrupted.

    The issue for the Arctic is the temperature of water in surrounding areas and flowing into and around the various land features. There will probably be winter sea ice in the Arctic for the next century or even a bit longer – but I don’t know how many human generations we can count on after that.

  48. Mark Shapiro says:

    FrankD, Joe, and Lou!

    Your graph just made a big splash on Andrew Sullivan’s Daily Dish:

    I’ll bet he gets some comments on this . . .

  49. Oale says:

    For those dreaming of a wintertime passage through the Sea of Northern Lights:

  50. John le Mesurier says:

    Yes, it is an interesting article but it comes as no surprise to anyone who takes the predictions of James Hansen or Natalia Shakhova seriously – and I do.

    Even less of a surprise is that temperature in the Arctic rises more in winter than in summer which, I would have thought, was a clear indication that warming ocean currents played the leading role in sea ice mass loss.

    I don’t know of any reason why that loss should be linear or occurring only in sunlight but I would be happy to read the views of others on this topic.

  51. StSimonsIslandGAGuy says:

    I wonder what the impact of adding millions of square kilometers of open water will have on the precipitation of arctic North America and Asia. Also what impact the increased water vapor will have as a positive feedback.

    My opinion, for what it’s worth, is that arctic sea ice will start having minima below 1 million square kilometers during the 2030s, and winter maxima below 1 million square kilometers by ~2100.

  52. adelady says:

    John le M, occurring only in sunlight … I know, I know.

    I just wish we’d had Cryosat for the last few years. My reading of the numbers is that the ice has just been eaten away from underneath during the freezing season by warm currents from the Atlantic (and the Pacific to a lesser extent). The reason the melt season has such a big impact is that there’s just so much less ice to be melted in the first place. The sunlight would be reflected if there were more and better ice surviving from earlier seasons. Having written that it starts to sound a bit similar to the glacier problem – glaciers decline when snowfall at altitude cannot keep up with ablation, melt and dispersal at the base. The sea ice can freeze all it likes at the top but it can’t sustain ‘proper’ thickness if that top freeze can’t keep up with melting from underneath.

    If we had 10 years worth of good satellite data, my impression and others’ estimations would all be more focused and accurate.

  53. Artful Dodger says:

    adelady #51:

    NASA’s IceSat provides data similar to what CryoSat2 promises. IceSat Level 3 data is available from 2003 to 2009. Before that, U.S. Submarine cruises and Tethered Buoys provide Ice thickness data going back 50 years. All of this historical data has been used to calibrate the PIOMAS model, and to validate its results.

    PIOMAS Monthly Sea-ice Volume estimates are probably no more than 10% off. Even 20% uncertainty would buy just one additional year before the Arctic Ocean is virtually sea-ice free.

  54. Mulga Mumblebrain says:

    John le M-I was just listening to you in an old episode of ‘Dads’ Army’. It’s great to hear from you. Now, tell us, how is it on the other side?

  55. John le Mesurier says:

    Mulga @ 55

    The le Mesuriers are a clan from Guernsey in the Channel Islands where they have lived since the 10th century. John/Jean is a common name among the le Mesuriers who are now common in French speaking Canada and to a lesser extent, Australia and New Zealand. This is highly off-topic – sorry moderator