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  1. Has anybody looked at the dates of the year for the minimum and maximum ice coverage and considered whether they’ve changed too? Presumably, over the time series, the average date of maximum sea-ice coverage would move earlier and the date for minimum sea-ice coverage would move later.

    Comment by Miguelito — 26 Aug 2012 @ 11:09 AM

  2. Do these data have the running 5-day averaging that (I think) NSIDC usually applies in its own communication?

    Comment by Kees van der Leun — 26 Aug 2012 @ 11:10 AM

  3. Mark that the only concrete urgency and most of the news from the Arctic has to do with our pathetic eagerness to go “up” and extract freshly available hydrocarbons so we can literally add gasoline to the fire consuming us.

    How very wise we are. Who needs an Oracle of Delphi speaking in riddles?

    Comment by dbostrom — 26 Aug 2012 @ 11:52 AM

  4. Capital Climate covers divers records and events including Tropical rainfall rate in arctic Alaska.

    The questions of comments 1 & 2 are probably answered at the remarkable Ice Empiricist blog.

    Comment by Pete Dunkelberg — 26 Aug 2012 @ 11:59 AM

  5. These are daily values, not the 5-day average, which is not quite at a record yet. Using a 5-day average removes some of the noise due to weather and other effects that cause small errors in the daily values. Thus the 5-day estimate is a more robust measure of sea ice changes. We will make an announcement on our web site when we have passed the current record: http://nsidc.org/arcticseaicenews/

    Walt Meier
    NSIDC

    [Response:Walt, thanks for stopping by, and for that clarification.--eric]

    [Response:Thanks indeed Walt. By the way, it is worth noting that while a trailing moving average does average out noise, this can come at a cost when the time series is non-stationary (as this clearly is): the moving average will necessarily dampen the trend near the end point of the series. The stronger the trend, the more this is so, so I think that is a problem here. Application of the same 5 day trailing average to the 2007 series (where the decline was much less steep at this point of the season than it is in the current case) is likely to have led to a less severe dampening of the decline than it is having now, where the decline is still quite steep. I believe that this likely has led to a spurious delay (by a day or two) in declaring the 2007 record beaten. Just my two cents. -mike]

    Comment by Walt Meier — 26 Aug 2012 @ 12:04 PM

  6. @Miguelito: https://sites.google.com/site/pettitclimategraphs/

    Comment by Killian — 26 Aug 2012 @ 12:14 PM

  7. Let me play devil’s advocate–though the MSM is playing that role quite well by it’s deafening silence on the issue:

    Why should we care? It’s just ice.

    Maybe not a good thing for some polar bears and Inuit, but why should the rest of us take even a moment out of our busy lives to worry about these developments?

    Comment by wili — 26 Aug 2012 @ 12:22 PM

  8. Neven and I try to summarize some of the consequences, insofar as they are known at this point, in a new post at the Arctic Sea Ice blog:

    http://neven1.typepad.com/blog/2012/08/wasislac.html#more

    Comment by Kevin McKinney — 26 Aug 2012 @ 12:26 PM

  9. @Walt (4) Thanks, that’s what I thought. The noise on the red line during the past few weeks doesn’t look too impressive though. Hardly shows at this steep gradient.

    Comment by Kees van der Leun — 26 Aug 2012 @ 12:26 PM

  10. Hmmmm…..say, could I interest anyone in a little ‘soon-to-be-oceanfront properties’ in, say, the foothills of the Brooks Range?

    Comment by James Staples — 26 Aug 2012 @ 12:49 PM

  11. Let’s get real. The big questions now are: “How bad?” and “How soon?”

    This melt should significantly impact climate models. Shouldn’t this melt mean it is time for a recalculation? Where can I see that?

    [Response: Climate models don't directly ingest observational data like this. However, the CMIP5 models do have updated calculations and many models show trends similar to that seen in these obs. - gavin]

    Comment by richard pauli — 26 Aug 2012 @ 12:58 PM

  12. If you stop a Gyroscope, remove material from top and bottom,
    then redistribute the material evenly about the gimbals, then restart the
    gyroscope it will rotate to achieve a new position of dynamic balance.
    Apparently the planet is susceptible to Newton’s laws of motion as well. With
    similar results expected when the Polar Ice Caps melt.

    [Response:Very small effect. - gavin]

    Comment by dennis baker — 26 Aug 2012 @ 12:58 PM

  13. @wili (6) Here’s three reasons:
    1) Positive feedback. Water absorbs more sunlight than ice, so reinforces global warming
    2) Potential strong effects on climate elsewhere, e.g. by changing jetstream patterns
    3) As a canary in the coalmine; sign that we’re messing with climate bigtime
    And for me, the fact that we’ve managed to destroy one of Earth’s big features in a few generations is enough.

    Comment by Kees van der Leun — 26 Aug 2012 @ 12:59 PM

  14. And if you can find me somebody who still thinks climate change is a hoax, I have a very attractive bridge for sale in Central London.

    Comment by idunno — 26 Aug 2012 @ 1:25 PM

  15. I’m concerned that this will also accelerate clathrate melting and CH4 release into the atmosphere. Any news on that?

    Comment by Peter — 26 Aug 2012 @ 1:40 PM

  16. wili,

    “It’s just ice.”

    Sigh.

    Please take the time to follow the link above to Neven’s blog, or this article by him at Skeptical Science, to find out how sadly wrong that statement is.

    Comment by Sphaerica (Bob) — 26 Aug 2012 @ 1:42 PM

  17. This calls for writing a Letter to the Editor.

    Comment by Edward Greisch — 26 Aug 2012 @ 3:09 PM

  18. Thanks, Bob.

    It was a happy serendipity that Kevin himself posted that link right under mine, as if an ‘angel’s advocate’ swept down directly from above to address my devilish pose.

    My point was that “So what?” is the position implicitly and tacitly taken by most of the media, and by implication by most of the population. So if we don’t directly address that position here, people casually walking by will be lost in the technicalities of the science and miss the point of why this concerns so many of us so deeply.

    In short, I see your sigh, and raise you a groan.

    Comment by wili — 26 Aug 2012 @ 3:10 PM

  19. OK the biggest thing can be seen on Neven’s site on the article peeking through the clouds 5. And of course: https://sites.google.com/site/apocalypse4realseaice2012/home/sea-ice-concentration-and-thickness-comparison . Although much slowed, spontaneous melting can still occur until surface temperatures reach -11 C. Of which this number might of changed since Arctic sst’s are on going really warm.

    Back to “Neven’s peeking through the clouds”, is very good, but can be made better if a similar animation can be done pre 1998. What is certain is the AO was not being particularly favorable for a great melt of 2012, neither was it sunny so much, rather rainy in the Arctic. Proving Piomas volume data robust, in short it takes very little clear high pressure weather to do a great extent melt.

    I’d like to thank Walt Meier for his organizations work, there is no dramatization needed, Arctic sea ice is transforming to become winter seasonal only, the larger impacts are huge, but the attention span of media about this is wee small.

    Wili, dont know where you are from, lets put it this way, transform your entire climate in your area, and get the Arctic change equivalency. Wherever you may be, this change is underway. I guess you’ll have to adapt to it.

    Comment by wayne davidson — 26 Aug 2012 @ 3:13 PM

  20. @Gavin, wrt to the CMIP5 model runs

    Have any of these results been published? Please, could you provide a reference? I have not been able to find a CMIP5 paper with trends near to those we see at present.

    Comment by Tenney Naumer — 26 Aug 2012 @ 3:20 PM

  21. > rather rainy in the Arctic.

    You could say that. You could say that. Tropical Rainfall Rate in Arctic Alaska.

    Comment by Pete Dunkelberg — 26 Aug 2012 @ 3:38 PM

  22. @19 that’s the most recent paper on sea ice trends in the models
    (this way please)

    Comment by ob — 26 Aug 2012 @ 3:47 PM

  23. O the perils of extrapolation, but the ice sure looks like its parachute failed to deploy and it’s *splat* time. An October minimum, anybody? A late, amazingly low minimum just before the US elections. Arctic sea ice might just become a big issue. I’m rooting for the lowest possible extent. Go melt go!!!

    “e CMIP5 models do have updated calculations and many models show trends similar to that seen in these obs. – gavin]”

    Cool. How do they tend to evolve? Do they indicate this is just a deviation or a legitimate trend?

    7 Kevin, nice work, but I disagree with ” in a world where energy is rapidly becoming more expensive.”

    The most expensive fossil energy I know of is tar sand oil at $20-25/ barrel. Fossil fuel’s price is constrained not by cost, but by profit and tax, as limited by renewables, which are decreasing in cost. As wind and solar drop to less than current fossil pricing, fossil’s price will drop too. “When renewables are competitive with fossil” is a pipe dream. True competitiveness is based on cost, not price. Of course, including externalities, such as the loss of sea-ice, makes fossil fuels quite expensive at any price.

    Comment by Jim Larsen — 26 Aug 2012 @ 3:55 PM

  24. OK… calling out for an entrepreneur for a digital display of data.

    It is way past time for an iPad/Smart-Android app or widget… we will need to see ice coverage, drought maps, heat waves, floods, storms and even crop reports. Any climate data that is a few days old. I am tired of visiting 20 or so sites just to see the latest data.

    This old method of waiting months and years for academic publishing cycles is not cutting it. Policy is poisoned by reliance on 2007 models. A simple climate change app doesn’t need IPCC sanctioning… just recent data. An app that is well-formed would let the user decide what data to input into a model to be displayed.

    The goal is not academic support, the goal is to inform the public on the latest information.

    An app could be from synthesized, modernized and combined climate models as a foundation – and would appear as the user wants to display it — on a smart phone, device or web page.

    It is about time for this, isn’t it?

    Comment by richard pauli — 26 Aug 2012 @ 4:51 PM

  25. Thank you, ob at 21.

    Stroeve et al.’s paper:

    “Results from the CMIP5 models do not appear to have appreciably reduced uncertainty as to when a seasonally ice-free Arctic Ocean will be realized.”

    Has anyone seen anything better in the literature?

    Comment by Tenney Naumer — 26 Aug 2012 @ 5:02 PM

  26. @Pete Dunkelberg (#20): The Alaskan heavy rain has continued into the past week. The 2.04″ at Nome is 275% of normal, and the season to date is running almost 200% of normal.

    Comment by CapitalClimate — 26 Aug 2012 @ 6:03 PM

  27. wili “My point was that “So what?” is the position implicitly and tacitly taken by most of the media, and by implication by most of the population. So if we don’t directly address that position here, people casually walking by will be lost in the technicalities of the science and miss the point of why this concerns so many of us so deeply”

    You are driving along and your OIL warning light comes on,

    “So what?”

    Comment by john byatt — 26 Aug 2012 @ 6:28 PM

  28. Wayne and John Byatt, thanks for the perspectives. For anyone unfamiliar with the term:

    “In common parlance, a devil’s advocate is someone who, given a certain argument, takes a position he or she does not necessarily agree with, for the sake of argument. In taking such position, the individual taking on the devil’s advocate role seeks to engage others…”

    So thanks for engaging, but don’t assume the stated position was mine.

    Meanwhile, here’s a list of possible effects compiled by “nothing-new-under-the-sun” in a comment on neven’s site.

    “1. Arctic ecosystem change/habitat loss
    2. Arctic (human) communities culture/infrastructure loss
    3. Albedo change to global energy budget
    4. Permafrost melt acceleration
    5. Methane clathrates destabilisation
    6. Greenland ice sheet melt acceleration
    7. Geo-political tensions over Arctic resources
    8. Exploitation of Arctic fossil hydrocarbon resources feedback
    9. Complex effects on NH wind/weather patterns via polar jetstream effects.

    10. I considered a tenth, namely, a further disruption to the global energy budget from the freeing of the latent heat energy that previously was being used to accomplish the phase transition of ice -> water, though my back of the envelope calculations suggest that this is a much smaller issue than albedo change (I’d love to see some reputable work on this topic as I’m far from any kind of expert).

    Now that I think about it a little more, I can think of a further seven issues that neither Neven&Kevin nor I mentioned. Some of these I’m very tentative about (esp ##15&16).

    11. The release of persistent toxins and heavy metals that had become trapped in the ice.

    12. The opening up of Arctic shipping routes which (a) reduces fuel needs of global shipping by cutting distances (negative feedback) but (b) brings more diesel fuel into the Arctic region, leaving black soot on glaciers (positive feedback). Not sure which is the larger effect.

    13. Reconnection of marine ecosystems previously separated by ice with unpredictable ecosystem changes from invasive species. This is already occurring.

    14. Opening up of Arctic fishing grounds to greater exploitation (and noise pollution).

    15. Potential effects on thermohaline circulation. I haven’t seen any work on this related to seasonal sea ice loss, so I have no idea whether it is significant.

    16. Potential effects on ocean acidification by increasing surface area for atmosphere-ocean gas exchange. Would this make any difference to ocean capacity to act as CO2 sink or rate of acidification? Maybe this is irrelevant. I haven’t seen it mentioned anywhere and is just an idea that came to me.

    17 . Highly visual and difficult to dispute sign of climate change, representing a potential tipping point in public awareness and concern. If we are waiting for that, however, before we make any serious efforts to slash emissions (esp if it doesn’t occur until 2030 or later), we’ll already have so much warming committed that we’ll pretty much be toast. At best, therefore, this point might consolidate public support for massive rapid emissions reductions already underway. But of course, by here, we’ve moved out of the geophysical and into the political systems, and so I’ll note the above comments and cease before travelling any further…”

    Comment by wili — 26 Aug 2012 @ 8:07 PM

  29. re: 27

    My first thought about consequences that we can perceive was that there will be an increase in out-of-season cold winds breaking out of the Arctic. If the outbreaks are severe enough, they will produce late Spring killing frosts. A few years ago, we had 4 days in April with dry, high winds and temps in the 20s. Push that forward a couple of weeks and it isn’t the loss of ornamental trees that we experienced: it would be a loss of the first agricultural planting for the year.

    My first impression anyway.

    Comment by Jeffrey Davis — 26 Aug 2012 @ 8:43 PM

  30. # 24 Agree Richard, I get IPCC AR4 thrown in my face all the time as being the current state of the science.

    Comment by john byatt — 26 Aug 2012 @ 9:32 PM

  31. > It is way past time for an iPad/Smart-Android app or widget we will need to see ice coverage, drought maps, heat waves, floods, storms and even crop reports

    Sure, that’s where they are many apps out there. Google is your friend, they don’t just find & install themselves.

    Here’s one “top 10″ listing, I’m sure if you spend a minute or two you can find some that you like, it didn’t take me long to find these.

    http://www.climatecentral.org/blogs/climate-science-theres-an-app-for-that/

    These cover at least some of your exact desires like Arctic Watch and Drought Monitor. Also, have you tried using the browser on your phone? Many sites, Real Climate included, have mobile friendly themes. I read RC on my phone frequently, even posted a couple times using it but typing truly sucks on phones.

    Comment by Unsettled Scientist — 26 Aug 2012 @ 10:38 PM

  32. > current state
    AR4 was a long, long time ago.
    The deadline for papers _considered_ in AR4 was rather longer ago.
    Try some of the links in this: https://www.nytimes.com/2012/08/26/business/carbon-tax-would-have-many-benefits-economic-view.html
    like http://journals.ametsoc.org/doi/abs/10.1175/2009JCLI2863.1
    or http://www.sciencedaily.com/releases/2012/08/120820114041.htm

    Comment by Hank Roberts — 26 Aug 2012 @ 10:40 PM

  33. Any thoughts on the relationship between the melting ice and the drought in the United States? Not that there is a direct link. I’m more interested in trends.

    [Response: No direct link - though of course both are influenced by rising temperatures occurring as a function of increasing greenhouse gases. - gavin]

    Comment by George — 26 Aug 2012 @ 10:47 PM

  34. #28 wili, It obviously was not your position, You seemed to be asking what it could mean for the man in the street,

    Tell him that the temperature (Arctic) and oil (Greenland) lights just came on while your were driving his car.

    what does it mean? well it means that first you must stop the car.

    It may be just a wiring problem the car may continue on, Do you want to take the chance of “so what”

    Comment by john byatt — 26 Aug 2012 @ 10:52 PM

  35. Wili: Thanks for a good list.

    18. Increased evaporation (more water vapor in the atmosphere) due to higher sea surface temperature. Even assuming that the summer ice surface used to be wet, 0 degC and low salinity which it was not always.

    19. Changed Arctic Ocean current patterns due to stronger wind drag over open water.

    20. Less stratification of waters from different origins due to more mixing near the surface (wind effects).

    21. Enchaced sea-to-atmosphere energy flow as the insulation formed by ice (and snow on it) diminishes.

    22. More first year ice containing more salt than old ice. Different ice properties.

    My favourite graph is still
    http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/sea.ice.anomaly.timeseries.jpg

    It shows clearly the steady decline, but also that a distict process mode change happened in 2007. Excessive summer melt has now repeated 6 times.

    Comment by Pekka Kostamo — 26 Aug 2012 @ 10:54 PM

  36. Hi everyone,

    I downloaded the daily data set from 1978-2012, and noticed the annual maximums appear to vary less than the annual minimums. There’s still a downward trend but not as noticeable.

    If true, does it mean the Arctic has remarkable recovery capabilities?

    Or, is it related to ice thickness?

    For example, if all the ice melted in the summer, new ice could form over a large area, yet be quite thin. Conversely, if the ice were quite thick the maximum area may not reflect new ice formation on top of existing ice. So maybe the maximum area is a bit more stable? …well, at least until it gets too warm year round for ice to form at all :(

    I didn’t have time to calculate the variance but here are the highs and lows for each category from 1978 to the present:

    Annual Minimum Daily Extent*:
    - Highest is 7.52 on Sept. 5, 1980
    - Lowest is 3.97 on Aug. 25, 2012
    - Difference: 3.55

    Annual Maximum Daily Extent*:
    - Highest is 16.56 on Mar. 1, 1979
    - Lowest is 14.69 on Mar. 7, 2011 (and this March it was 15.29)
    - Difference: 1.87

    * Area in 10^6 km^2

    Sorry if this is basic climatology knowledge, I’m far from an expert.

    Thanks,
    Scott

    Comment by Scott — 26 Aug 2012 @ 11:04 PM

  37. [Sorry, wili. I misread the context/tone of your post. Apologies. Still, at least it was an opportunity to post the link.]

    Comment by Sphaerica (Bob) — 26 Aug 2012 @ 11:46 PM

  38. 24, 30, et al.: I’ve been using a movie of diminishing ‘old’ sea ice from http://www.climatewatch.noaa.gov/video/2011/old-ice-becoming-rare-in-arctic as an educational tool. I don’t think a single site for AGW impact info is as important as having more sites like climatewatch, and having them link to each other.

    It’s not just this record breaking year for Arctic ice that is being ignored in the MSM in the U.S. Southern Europe is in the grip of a heat wave complete with numerous fires (e.g., http://news.sky.com/story/975467/heatwave-fuels-wildfires-across-europe) but you wouldn’t know it from the Washington Post, New York Times, or Wall Street Journal.

    28: Effect # 17 (“tipping point in public awareness and concern”) will not occur in the U.S. if there is no comprehensive reporting of what’s going on.

    Comment by Toby Thaler — 27 Aug 2012 @ 12:26 AM

  39. Can anyone explain these two seemingly different visualization of Arctic sea ice extent on 8/25/12 (hopefully the links aren’t out of date)

    NOAA and NSIDC

    Comment by Chris Colose — 27 Aug 2012 @ 1:05 AM

  40. #24 richard pauli

    I’ve put together a decent set of updating charts on the OSS site.

    http://ossfoundation.us/the-leading-edge/projects/environment/global-warming/current-climate-conditions/

    Global Climate Monitor with sections focused on

    - Arctic
    - Antarctica
    - Atmosphere
    - Greenhouse Gases
    - Oceanic Climate
    - Temperature
    - Solar
    - Storms & Trends
    - Land

    Most update daily, some are monthly, some update hourly, 15 minutes, 5 minutes and 60 seconds.

    Comment by John P. Reisman (OSS Foundation) — 27 Aug 2012 @ 1:31 AM

  41. Well,

    ‘We can expect to see an ice-free Arctic at about the middle of this century.’ said yesterady prof. Will Steffen, executive director of the Australian National University’s Climate Change Institute.

    This is not Konrad Steffen, who I think would disagree with such estimate.

    I think 2020 +/- 5 years is a more reasonable estimate…

    Alex

    Comment by Alexander Ač — 27 Aug 2012 @ 4:28 AM

  42. Thanks to Tenney for pointing to:
    http://www.agu.org/pubs/crossref/2012/2012GL052676.shtml

    From the abstract:
    “Previous research revealed that the observed downward trend in September ice extent exceeded simulated trends from most models participating in the World Climate Research Programme Coupled Model Intercomparison Project Phase 3 (CMIP3). We show here that as a group, simulated trends from the models contributing to CMIP5 are more consistent with observations over the satellite era (1979–2011). Trends from most ensemble members and models nevertheless remain smaller than the observed value.”

    So most models still underestimate the speed of the actual decline in Arctic sea ice?

    Comment by Lennart van der Linde — 27 Aug 2012 @ 4:34 AM

  43. Scott @ 36: “I downloaded the daily data set from 1978-2012, and noticed the annual maximums appear to vary less than the annual minimums. There’s still a downward trend but not as noticeable.”

    The winter maximum is rather hampered by land isn’t it? Try comparing the maximum extent to the areas where it has a chance to grow.

    Comment by Pete Dunkelberg — 27 Aug 2012 @ 5:35 AM

  44. 27 John Byatt. I think it’s more like you’re driving along and suddenly your front tyres explode and you are veering wildly from side to side of the road …”So what” (taking a geological time scale here).

    Comment by Lawrence Coleman — 27 Aug 2012 @ 5:50 AM

  45. Re: #36 (Scott)

    At least some of the effect is due to geometry and the placement of land masses in the northern hemisphere. See this:

    http://tamino.wordpress.com/2010/08/22/on-ice-with-a-twist/

    Comment by tamino — 27 Aug 2012 @ 5:53 AM

  46. Chris Colose,

    NOAA/NIC/IMS is also the source of NSIDC’s MASIE product. There’s some text about the difference between MASIE and their Sea Ice Index product in the documentation. There’s also a page documenting the IMS analysis itself.

    Comment by Paul S — 27 Aug 2012 @ 6:16 AM

  47. Gavin’s comment @33

    Any thoughts on the relationship between the melting ice and the drought in the United States? Not that there is a direct link. I’m more interested in trends.

    [Response: No direct link - though of course both are influenced by rising temperatures occurring as a function of increasing greenhouse gases. - gavin]

    Doesn’t Jennifer Francis say different. See Does Arctic Amplification Fuel Extreme Weather in Mid-Latitudes?

    Comment by Geoff Beacon — 27 Aug 2012 @ 6:25 AM

  48. Thanks again john, bob (no apology needed), and especially pekka for your engagement and contributions.

    Chris, it is my impression from noodling around obsessively at neven’s and other arctic sites that different organizations have different thresholds for what they consider ice covered water. I don’t have the stats for those sites, but consider how different a map that considers areas with 15% coverage to be included in extent versus 30% or more. My impression is also that extent maps function especially to help navigators know where they can safely go with their ships. Different ships would have different tolerances for different concentrations of ice, I imagine. So it is probably useful to have a variety of measures out there.

    Somewhere on the sites there should be a place where each site explains its criteria for extent determination. I just don’t have time to do that search right now. Hope this helps. (But don’t take my word for it.)

    Comment by wili — 27 Aug 2012 @ 6:31 AM

  49. By the way, CT SIA set a new record today: 2.64316 million k^2

    http://arctic.atmos.uiuc.edu/cryosphere/arctic.sea.ice.interactive.html

    A lot of bumping up and down for ice area now, even as ice extent falls. Presumably a lot of compaction going on. And freezing in some areas, thaw and transport out in others.

    Comment by wili — 27 Aug 2012 @ 6:35 AM

  50. It just occurred to me that if the source of the Alaska rain is indeed the arctic the surface salinity has to be climbing as a result. What I mean to say is the Arctic Ocean salinity on the surface is usually lower than other sea area’s because of meltwater and river influx freshening. If mass quantities of fresh surface water are departing as cloud masses and raining out to south of the continental divide in Alaska that rain will make its way to the Pacific instead of back into the Arctic. This will have at least two effects, the Arctic will be more saline and harder to freeze in winter, and the mass lost will be replaced by currents flowing into the basin mostly from the Atlantic.

    Comment by Allen W. — 27 Aug 2012 @ 6:47 AM

  51. For the list of potential effects:
    As the ice melts and spreads evenly as fluids tend to do, the tectonic plates are going to go through a lot of adjustment. Meaning earthquakes.

    Comment by kristiina — 27 Aug 2012 @ 7:28 AM

  52. Here is an idea for graphically displaying the concept that the loss of Arctic ice will lead to more persistent weather — choose two cities in the Northern Hemisphere from substantially different longitudes and plot the difference between their weekly highs over an extended period of time. This curve should show a change in behavior over the most recent 20 to 30 years.

    Comment by Donald Dresser — 27 Aug 2012 @ 7:35 AM

  53. Chris,
    This was posted on Nevens’ blog. I didn’t copy the hot links.

    For those wondering about the NIC estimates (as can be seen here: http://nsidc.org/data/masie/, NIC produces operational ice analyses, focused on using many data sources of varying quality and quantity to detect as much ice as possible, even small concentrations. NSIDC’s passive microwave data may miss some low concentrations (it uses a 15% concentration cutoff), particularly during melt. So it’s not unusual for NIC/MASIE to show more ice, though it’s more than in other years because the low concentration ice is scattered over a much larger area.

    An important point is that NIC/MASIE, while picking up more ice, is produced via manual analysis and the data quality and quantity varies. So the product is not necessarily consistent, particularly from year-to-year. NSIDC’s product is all automated and consistently processed throughout the record. So there may be some bias, but the bias is consistent throughout the timeseries. This means that comparison of different years, trend values, and interannual variability are more accurate using NSIDC.

    Hope this info helps.

    Walt Meier
    NSIDC

    Comment by michael sweet — 27 Aug 2012 @ 7:49 AM

  54. john byatt says: 26 Aug 2012 at 10:52 PM Tell him that the temperature (Arctic) and oil (Greenland) lights just came on while your were driving his car.

    what does it mean? well it means that first you must stop the car.

    No, no. It means you crank up Rush Limbaugh louder, drown out the clattering, banging noises coming from under the hood. Twist the rearview mirror up so you can’t see the smoke clouds trailing behind.

    When you’re sitting by the road waiting for the tow truck, pull up Watts on the smartphone and read about how it never actually happened, that your engine is suffering from natural variability, not owner failure.

    Comment by dbostrom — 27 Aug 2012 @ 8:41 AM

  55. Chris,

    This was posted at Neven’s blog:

    For those wondering about the NIC estimates (as can be seen here: http://nsidc.org/data/masie/, NIC produces operational ice analyses, focused on using many data sources of varying quality and quantity to detect as much ice as possible, even small concentrations. NSIDC’s passive microwave data may miss some low concentrations (it uses a 15% concentration cutoff), particularly during melt. So it’s not unusual for NIC/MASIE to show more ice, though it’s more than in other years because the low concentration ice is scattered over a much larger area.

    An important point is that NIC/MASIE, while picking up more ice, is produced via manual analysis and the data quality and quantity varies. So the product is not necessarily consistent, particularly from year-to-year. NSIDC’s product is all automated and consistently processed throughout the record. So there may be some bias, but the bias is consistent throughout the timeseries. This means that comparison of different years, trend values, and interannual variability are more accurate using NSIDC.

    Hope this info helps.

    Walt Meier
    NSIDC

    [Response:Thanks! -rasmus]

    Comment by michael sweet — 27 Aug 2012 @ 8:57 AM

  56. Kevin McKinney’s Skeptical Science summary of the global impacts of sea ice decline is a good one, but the public still has no idea. The reason is continued intimidation of mainstream media by the fossil fuel companies, especially since the largest single revenue stream for most media outlets comes from new car ads.

    We are hurtling toward a crisis, a fact well known by most Realclimate readers. Isn’t it time that formal approaches to television networks and major newspapers got under way? Framing this issue over whether one thinks polar bears are necessary is just what the oil companies would like to see happen.

    Letters to editorial boards and statements from scientific organizations have either been ignored or posted on page 16. A serious media strategy is needed, with input from scientists, and boots on the ground to insist on private audiences with the owners of our media companies.

    Editors and reporters are too scared for their jobs to act. We have to go straight to the top on this one, including handouts at shareholder meetings, as well as other strategies yet to be developed. For starters, media company owners need to be told that the notion of accelerated drilling in the Arctic is madness.
    Otherwise, those of us who pay attention to the science on this subject will continue to be just a geeky niche.

    Comment by Mike Roddy — 27 Aug 2012 @ 9:00 AM

  57. > ice area

    The decline in the ice area at _maximum_ is also interesting to look at over time.

    Comment by Hank Roberts — 27 Aug 2012 @ 9:06 AM

  58. Pete @ 42, Tamino @44,

    Thanks, this makes sense.

    It’s impressive that the sea ice can rebound so well given the minimum trend. I guess there’s a relationship between the rate of ice formation and the existence of “survival” ice. Maybe the surviving ice acts as an insulator making it easier for new ice to form.

    Comment by Scott — 27 Aug 2012 @ 9:13 AM

  59. #41 Lenart Van De Linde,

    The pattern seems to be that the models that produce a more severe volume loss, which will imply increased area/extent loss due to increased open water formation efficiency, are assimilating models and have higher resolution than GCMs. Because the assimilating models (PIOMAS/NPS) use ‘observed’ atmospheric changes, it seems likely that atmospheric changes play a key role. By ‘observed’ I mean reanalysis and current weather forecast model data.

    Maslowski claims it’s higher resolution, but to quote from something I wrote on my blog:

    PIOMAS “has a horizontal resolution of 40 km X 40 km, 21 vertical ocean levels, and 12 thickness categories each for undeformed ice, ridged ice, ice enthalpy, and snow.” NPS “is configured using a horizontal, rotated spherical grid covering 1280×720 cells at a 1/12 degree (approximately 9km) resolution. It has 45 vertical layers” in the ocean. So whilst Maslwoski has asserted that resolution is a key factor it doesn’t seem to be the case when PIOMAS is considered, NPS is 9km square, PIOMAS 40km square.

    It seems to me that the common factor most likely to be the key is that assimilating models assimilate what the atmosphere is doing, including its response to the loss of sea ice. GCMs have this feedback, but for example they overestimate the strength of the winter inversion (Boe et al) so they would grow more ice than in reality, which would reduce volume loss and thence area/extent loss.

    Comment by Chris Reynolds — 27 Aug 2012 @ 11:08 AM

  60. Kristina,

    The Arctic sea ice is floating on the ocean, so it displaces its own weight in water, its weight is distributed throughout the oceans – and is negligble compared to the weight of the oceans. It’s not like the Greenland or Antarctic ice sheets which sit on land. Its loss will have no tectonic effect, none at all.

    Comment by Chris Reynolds — 27 Aug 2012 @ 11:12 AM

  61. Reply to #38: Thanks for the link on fires in Europe. Funny you should post that because just the other day I was thinking it was odd that only the US seemed to be suffering heat waves and fires this Summer. Interesting how MSM reported Russia’s fires the year they occurred, but not the fires in Europe this year. Wonder if they got marching orders to avoid GW type related events. It would also explain why there seems to not be much of any reporting on the current record Arctic melt. This is definitely a case of ignoring a developing catastrophe will not make one ioda of difference in how bad things get, only how lacking we will have been in reducing our carbon footprint.

    Arson was mentioned as an ignition source for many of the fires, (although I’m sure the fires are worse due to dry, hot weather) and I wonder if that is a reflection of the frustration many people are having in Europe right now due to high unemployment.

    Comment by Perk Earl — 27 Aug 2012 @ 11:33 AM

  62. My thoughts on the relationship between the melting ice/polar amplification and the Hadley cell/Rossby Waves/drought in the United States -

    Lets build a simple kitchen model. Take a 0.7m/24inch long food service pan with 0.1m/4inches of water in it. Put one end over a stove burner(the tropics), and tilt the pan so the other end(the pole) has a thinner layer of water(tropospheric thickness) over it. Turn the burner on low(solar+GHG forcing), put a few drops of food coloring in and watch the convective circulation(Hadley Cell) form. Note the position of the downward return flow of fluid(Hadley Cell dry zone). Tilt the pan so that the pole end has a thicker layer(increased tropospheric thickness due to polar amplification of GHG warming)[1]. I believe that the downward return flow(Hadley Cell dry zone) will move toward the pole(drought in SW united states and Europe) because the geometry of the flow changes. Now turn up the burner(increased GHG forcing); the convection (Hadley Cell) will expand even further.
    I’d bet one could take a large paella pan on a turntable with a burner at the edge, and play with the rotation speed, volume of water, and thermal input to generate a model with analogues to polar/Hadley/Ferrel cells and Walker circulation. If you floated a viscous layer of oil(stratosphere) on the water(troposphere), you could change the coupling between coriolis effects and thickness.
    Or competent climatologists could just model it – &;>) – for a mathematically rigorous starting point (WAAY beyond my math skills), see A Barotropic Model of the Interaction between the Hadley Cell and a Rossby Wave, Held and Pillips, Journal of the Atmospheric Sciences, Vol. 47, No 7, Oct 1989

    [1] Our simple model allows us to adjust the “troposphere thickness” independently of forcing/temperature gradient/AGW, but in the real world tropospheric thickness is an emergent property of two temperature gradients – tropical/polar and moist(ish) adiabatic lapse rate, both changed by AGW.

    Comment by Brian Dodge — 27 Aug 2012 @ 11:50 AM

  63. Is the figure dynamically updated?

    [Response:No - sorry. Rasmus]

    Comment by Brian Dodge — 27 Aug 2012 @ 11:53 AM

  64. 50 kristina: The overall implications for a changing climate are severe enough for a planet where the entire world’s infrastructure, forestry and agricultural practices are based on a historic climate that increasingly no longer exists, that we don’t need to try and link climate change to the tectonic forces that generate large earthquakes. Any geophysicists here?

    Comment by tokodave — 27 Aug 2012 @ 11:54 AM

  65. Why is there so little analysis of barometric pressure trends and possible relationships to warming, Arctic ice loss, and other patterns? Am I missing it? My search of scholar.google turns up “Variability and Trends of Air Temperature and Pressure in the Maritime Arctic, 1875–2000,” Polyakov et al. 2002, but not much else. Is it an irrelevant factor, and if so, why?

    [Response: There's a lot out there on the winds in 2007, which dominated the loss. Look up Stroeve for example. That probably applies to this 2012 ice loss as well. --eric]

    Comment by Toby Thaler — 27 Aug 2012 @ 1:02 PM

  66. NSIDC made it official

    http://www.washingtonpost.com/national/health-science/arctic-sea-ice-hits-record-low-scientists-say/2012/08/27/0e11a63a-efe6-11e1-892d-bc92fee603a7_story.html?hpid=z2

    But there is always a “but” by MSM, the skeptics science must surely impress them.

    Comment by wayne davidson — 27 Aug 2012 @ 1:19 PM

  67. Here’s a quick Popular Mechanics interview with Walt Meier on some of the details of how sea ice extent is measured, and some notes on extending the timeline earlier than 1979, when consistent satellite data began. Nothing startling for most people on this site, but could be useful. (Oh, written by me, by the way.)

    http://bit.ly/RgEBuE

    Comment by Jerry Beilinson — 27 Aug 2012 @ 1:20 PM

  68. Could someone explain the difference between the main NSDC analysis and NSIDC IMS graph which is not at a minimum? I guess they meassure the ice extent differently, but what is the difference?

    http://www.natice.noaa.gov/ims/

    Comment by Petter — 27 Aug 2012 @ 1:43 PM

  69. Received this today and send it along “as is” and hope it is appropriate to do so:

    Cc: “dschneid@ucar.edu”
    Subject: [CRYOLIST] Arctic sea ice data set inter-comparison and new resource available

    Dear colleagues,

    With all
    of the attention on Arctic sea ice, the resource that we’ve been putting
    together on the Climate Data Guide, climatedataguide.ucar.edu/seaice, may be of
    interest.?

    Here is
    one figure comparing 2003-2007 September mean sea ice concentrations across 10
    data sets:
    https://climatedataguide.ucar.edu/sites/default/files/key_figures/SIC_climatology_September_2003_2007_obs_Arctic_low_0.png

    It’s
    particularly surprising that there have been so few systematic comparisons of
    sea ice climatologies and trends among the many data sets. Currently, records
    are being broken across most if not all of the major satellite and algorithm
    combinations, but I think the differences (esp. for sea ice concentration and
    area) are important in the context of comparing observed sea to coupled models,
    calculating surface fluxes, and prescribing boundary conditions for atmospheric
    models.

    The
    Climate Data Guide aims to gather knowledge on the strengths and limitations of
    numerous climate data sets, including sea ice concentration. We post well
    informed and substantiated expert commentaries. Each page also has a comments
    section at the bottom for more informal tidbits. Please consider making a
    contribution; it is a relatively painless process. It is described more at https://climatedataguide.ucar.edu/contribute. Sea ice is just one of
    many topics. For instance, there is a lot of interest at NCAR in the
    performance of various renalyses in the polar regions. Surely there is
    knowledge out there that could be given a little more daylight?

    A side
    benefit of gathering these data sets has been the development of one of the
    more searchable (IMHO) data sites. See https://climatedataguide.ucar.edu/guidance/sea-ice-concentration-overview-and-comparison-tables#Tablefor specific sea ice
    information, or https://climatedataguide.ucar.edu/all-datasets/tablefor a more generic
    representation of data set attributes.

    Thanks
    for your interest.

    Sincerely,

    David
    Schneider

    Comment by BillS — 27 Aug 2012 @ 3:59 PM

  70. This close to what could be the end of September ice, the usual rule of thumb, that adding one more data point adds little value, weakens. Even a partial data point, such as 2012 so far, becomes quite helpful.

    The first Key Point of http://www.agu.org/pubs/crossref/2012/2012GL052676.shtm is:
    “CMIP5 models continue to underestimate rate of sea ice loss”

    It’s possible that “reality” isn’t an average run. Otherwise, we’re in a race of sorts to see if a model can “predict” the event before it happens.

    So, we’ve got a complex tool which isn’t quite(?) ready to do the job, and we’ve got “the perils of extrapolation”.

    But then, there really isn’t any action plan, other than to ensure that as much oil can be extracted as soon as possible.

    54 Mike R said, “the largest single revenue stream for most media outlets comes from new car ads.”

    I just saw a jay Leno’s garage episode showing GM’s BIG truck and SUV versions of the Volt. Leno was impressed. They quoted 100 to 1000s of MPG. Eyeroll. Anyway, converting the fleet to series-hybrid, which is what GM seems to want to do, would require lots of ads. I think Owner/Executive agenda counts for more. Ads happen based on circulation. And, owning a media company is becoming more and more about exercising your right to personal free speech.

    Comment by Jim Larsen — 27 Aug 2012 @ 4:31 PM

  71. by Carlos Duarte
    Director, Oceans Institute at University of Western Australia

    Groundhog Day: The ice extent in the Arctic Ocean reaches a new minimum

    I received a phone call from a journalist this week interested in my thoughts on the new minimum of Arctic ice sheet, since I published a paper earlier this year, arguing that the dynamics of the Arctic ice sheet is signaling at the proximity of a tipping point.

    In our conversation he asked whether I was prepared to speculate on the possible causes of this new minimum. I found the question a little perplexing and conveying an intense sense of deja-vú, as this is a recurrent experience every month of August for at least the past 6 years.

    In the 1993 movie Groundhog Day), Bill Murray is a TV weather reporter who finds himself locked onto the same day, waking up to same sequence of events repeating themselves over an over on a loop.

    With so much evidence there, how can we continue to ponder on the possible ultimate causes of Arctic ice loss?

    The noise on the climate change debate has reached such level that my colleagues in the US, particularly scientists within Federal agencies, tell me that they avoid taking a position on climate change in public conversations and news releases.

    The reluctance of the US public to agree with the wealth of scientific information pointing to an on-going and future warming of the climate due to anthropogenic green-house gas emissions seems to be curving now with the severe heat, drought and crop failure in the US this year.

    rest of short article here:
    http://theconversation.edu.au/groundhog-day-the-ice-extent-in-the-arctic-ocean-reaches-a-new-minimum-9070

    It is way overdue imho, that scientists all over the world begin to speak in a language that people can understand, and stop dithering. iow be BLUNT, and gain attention through BIG OPINIONS – and use those tools spoken of in the book Language Intelligence recently mentioned.

    Americans (the #1 indulgent polluters in the world by size) are the slowest dim witted people on the planet – that’s why media orgs like FOX NEWS even exists. Time to fight fire with fire isn’t it?

    [Response: Let's be fair now. The U.S., Australia and Canada are together the worst polluters on a per capita basis. Last time I checked, Canada was worst. As for dim-wittedness, well, fingers can be pointed at just about everyone, everywhere. --eric]

    Comment by Sean — 27 Aug 2012 @ 5:04 PM

  72. It’s a shame the graphic says “Januay” not “January”! Can someone please change the spelling? It loses some of its authenticity!

    [Response:Fixed. Thanks! --eric]

    Comment by Harmsy — 27 Aug 2012 @ 5:06 PM

  73. Interesting how MSM reported Russia’s fires the year they occurred, but not the fires in Europe this year. Wonder if they got marching orders to avoid GW type related events.

    I’ve seen coverage of fires in Spain, in particular one island where firefighting aircraft were returned to the mainland when they thought the fire was controlled, only to see the fire blow up and the aircraft unavailable for over 24 hrs.

    Perhaps there’s less coverage than for the Russian fires because a) the Russian fires were horrendously extreme b) it’s a Presidential election year in the US and the incumbent is at much greater risk than normal c) events in the middle east (particularly syria) are claiming a lot of the column inches available for international coverage by the US press.

    Conspiracy-thinking light “maybe they’ve been told not to cover GW events” is a bit too tinfoil-hattish for my taste.

    Comment by dhogaza — 27 Aug 2012 @ 6:49 PM

  74. There’s nothing happening. Tony T. Watt has produced (discovered/uncovered/stumbled upon) a graph that shows less than a rock-bottom minimum record. Walt Meier even contributed to try and clarify the issue, but it already had the numb in the number.

    http://wattsupwiththat.com/2012/08/27/sea-ice-news-volume-3-number-11-part-2-other-sources-show-no-record-low/

    No rock is left unthrown … but for a parallel, Tony guided me to the ‘non-record-setting’ graph once before: the Danish 30% threshold group. He didn’t use it, or reference it, this time around:

    http://ocean.dmi.dk/arctic/icecover.uk.php

    Comment by owl905 — 27 Aug 2012 @ 8:17 PM

  75. Re- Comment by dhogaza — 27 Aug 2012 @ 6:49 PM:

    In my not so limited experience, with the exception of commentators and news agencies with obvious biases, much of the mainstream news focus is due to incompetence, gullibility, and a sort of big buzz profit motive.

    News be entertainment. Steve

    Comment by Steve Fish — 27 Aug 2012 @ 9:19 PM

  76. Since the summer minimum is getting so close to zero, the graph would be clearer if the scale on the vertical axis started at zero rather than 4M km^2. At the rate things are going, by mid-September this year the sea ice extent will likely be below 4M km^2 anyway.

    Comment by Gerry Beauregard — 27 Aug 2012 @ 10:55 PM

  77. 50, Allen W., 27 Aug, 6:47 AM

    Alaska is a large state when compared to other in the US, but the affected area is quite small. It’s about like extrapolating weather on Cape Cod and Mass bay to all of New England and the Mid-Atlantic States.

    As well, Kivalina is some distance north of the Bering Straits on the east coast of the southern Chukchi Sea. The Chukchi is a named portion of the Arctic Ocean. Kivalina’s the village that needs to relocate due to increased erosion from fall storms, as it no longer has a sea ice buffer formed before their onset and gets much media attention as a climate change affected “poster child”. Here’s the latest.

    http://www.alaskadispatch.com/article/when-will-drenched-kivalina-be-able-open-its-school

    Comment by WhiteBeard — 28 Aug 2012 @ 1:07 AM

  78. Steve Fish @74: You left out the fact that the major media outlets all borrow endlessly from each other so that a great percentage is edited and subbed, if not written, by people a long way from the action, i.e. people who don’t know much about it. That adds ignorance to incompetence and gullibility.

    Comment by MalcolmT — 28 Aug 2012 @ 2:18 AM

  79. Cudos to Mr Tamino on his web site about WUWT author and followers falling into even greater ignoramus fame. By the way I am encouraged to expose their accomplishments more because of the way they responded to Mr Meier

    Now lets process WUWT ability with prediction the scientific way

    June Extent Outlook
    WUWT and Neven photo bucket
    2012 4.9 million km square 4.0 /Watts off by more than 0.9 million km2
    2011 5.5 4.5 /Watts off by 1 million

    How revealing, a perfect record of failure!… Mr Watts your ultimate peer is not only found in academia and science institutes, but in the future, by which you have failed. Review your understanding of the science or continue failing.

    Now about this very strong early August cyclone, there is a great disparity between a melt influenced by High pressures (2007) and a cloud covered super cyclone (2012 http://neven1.typepad.com/blog/2012/08/arctic-storm-part-3-detachment.html). Anticyclones push the ice outwards, cyclones consolidate ice inwardly. Which was the case in 2012. However the mega cyclone in question did some mixing of warmer sea water and already existing very weak thin sea ice. A “hot” super anticyclone would have probably done more melting and flushing. Again
    emphasis must be placed that there was lack of sunshine in summer of 2012 yet 2012 melt was greater than 2007. The decline of Arctic sea ice may be permanent, possibly delayed but by ideal future summer weather conditions, a possible long shot would be delaying melting by a very cloudy spring early summer, and a cool late August September Anticyclonic influence either scenarios twinned with a very strong La-Nina in the middle of winter during the long night. ….. Otherwise welcome to the new warmer world not quite the same as the old world.

    Comment by wayne davidson — 28 Aug 2012 @ 2:33 AM

  80. 71 Sean. I’ve being saying exactly that for years mate!, it seems as though scientists haven’t got the foggiest clue how to connect to the layman. But Gavin made the point earlier about creating your own personal blog, if you happen to be articulate either orally or with penmanship (keypadmanship) and if you can actually grasp the true gravity and significance of what is happening in front of our very eyes as opposed to wishing it away(the cowardly american approach) then for christsake create a blog with your ideas (as long as they are grounded in good science) and go selling it on facebook or twitter etc. I agree..Time to fight fire with fire! As it stands now, the best we can probably do is keep life..or what vaugely resembles life teetering along in a living hell for thousand of years. Whether humans actually make it is by the by. Don’t forget the oceans will be inhospitable to life for an epoch. Still I refuse to give up fighting until the last bullet takes me to the ground, that’s just my nature.

    Comment by Lawrence Coleman — 28 Aug 2012 @ 3:16 AM

  81. 77 WhiteBeard 28 Aug 2012 at 1:07 AM

    I might have put up the wrong link, the story I was referring too was about torrential rain in Nome, AK, where the mouth of the Yukon river discharges into the sea. Rain that falls north of the continental divide naturally ends up back in the Arctic ocean, but the stuff that falls south of the divide ends up in the Yukon or its tributaries and ends up in the Bering Sea.

    Comment by Allen W. — 28 Aug 2012 @ 8:35 AM

  82. Lawrence Coleman@80

    “(the cowardly american approach)”

    Really?

    Michael Mann is an American (as are many of the RC core). So is James Hansen. Al Gore. And the myriad of American activists who work on the Climate Change issue all over the world – many of whom have been killed.

    Explain to me (and to everyone, if you would be so kind), please, A.) how these both famous and uncounted men and women are cowards; and B.) how your comment has a place on this site – devoted to the science of Climate Change and its spread.

    That was completely uncalled for.

    [Response:I'm not aware of anyone having been "killed" for climate change activism. I would hope it doesn't come to that. --eric]

    Comment by Jaime Frontero — 28 Aug 2012 @ 9:01 AM

  83. What happens to these datasets when the assumption that the area around the pole that is above the inclination of the satellite(s) is fully covered in ice no longer holds? Do we have any alternative ways to collect information about that part of the ocean, maybe from aircraft?

    Comment by Douglas McClean — 28 Aug 2012 @ 10:52 AM

  84. Typo: “the annual sea-ice minima usually is observed”
    either “minima … are observed” or “minimum … is observed”
    (It just bugs me seeing this right at the top of the article.)

    Comment by Henry — 28 Aug 2012 @ 11:02 AM

  85. owl905, it appears that Anthony Watts hasn’t read the manual for MASIE at NSIDC. It specifically says that this is a bad product to for analyzing longterm trends due to climate change.

    “While operational analyses are usually the most accurate and timely representation of sea ice, they have errors and biases that change over time. If one is interested in long-term trends in sea ice or how it responds to changing climate forcing, generally, it is best not to use an operational product, but rather one that is consistently produced and retroactively quality controlled. The NSIDC Sea Ice Index monthly ice extent, and the satellite passive microwave data sets upon which it is based, is one example. The Sea Ice Index gives a daily image of extent as well as monthly products. However, these daily images are not meant to be used for climate studies or for inferring anything longer than seasonal trends. Satellite data are not quality controlled quickly enough; and for reasons explained in the Sea Ice Index documentation, the daily ice edge position can be off by tens of kilometers or more from the ice edge that an analyst would draw. Reasons include known errors in thin ice detection, bias in summertime concentration estimates, and the relative compactness of the marginal ice zone. See Partington et al. (2003) for an assessment of operational versus satellite-derived ice concentration.”

    http://nsidc.org/data/docs/noaa/g02186_masie/index.html

    My guess is that Watts doesn’t care that he is using a product that has errors and biases built-in to long-term trends because those errors and biases currently support his point. He is likely willfully ignoring the fact that this is a bad product to use to determine climate responses, and doesn’t care that the data sources and analysts NIC uses may have changed over the course of just a couple weeks.

    [Response: Whatever credibility Watts might have had has now been completely erased by his abuse of FOIA (publishing personal family details about people is not the intent of FOIA). --eric]

    Comment by Unsettled Scientist — 28 Aug 2012 @ 11:02 AM

  86. Eric, that may be a reference to this recent report:
    http://www.guardian.co.uk/environment/2012/jun/19/environment-activist-deaths

    [Response: Fair enough, but this is rather different. There is a big difference between first-world climate change activists and third worlders just trying to defend their lands. I'm not saying that any of this isn't serious and alarming, but it is best not to conflate these things.--eric]

    Comment by Hank Roberts — 28 Aug 2012 @ 11:12 AM

  87. #65 Toby and Eric,

    Toby,
    You’ll find a list of papers about 2007 at the end of this post. You can also find posts at my blog under the tag ‘Arctic Dipole’.
    http://dosbat.blogspot.co.uk/search/label/Arctic%20Dipole
    There are links to papers under each of those posts, you can then use the references of those papers to explore the issue further.

    Eric,
    Unless you have unpublished information I don’t have, I really don’t see this year as at all analagous to 2007. In block quotes is how I understand 2007, to save you having to wade through that to get to my point.

    As with 2007 2010 and 2011, this year, as soon as the sea ice edge entered the Arctic, the anomalies (Cryosphere Today area) fell through the floor.
    http://farm9.staticflickr.com/8284/7874765920_345d7983d3_o.jpg
    2010 later recovered somewhat, but 2011 and 2012 were at least as low as 2007.

    NCEP/NCAR doesn’t show 2007 like synoptic patterns in 2012 and 2011, nor does it show anything atypical of the 2000s IMO. So I see 2007 as due to the specific process outlined in below (block quote). What happened in 2011 and 2012 is different. Both years show record loss from Jun 1st to July 31st, 2008 to 2010 was around 5.4M km^2, 2011 & 2012 over 5.8M, 2007 under 5.8M.

    I am becoming more convinced that the last two years are as a result of a massive volume loss in Spring 2010. Here’s a graphic of the PIOMAS volume series (blue) and interannual changes (red), in 1000km^3.
    http://farm9.staticflickr.com/8433/7855584306_dd77ef2109_o.jpg
    This was done for a different purpose so it’s for Oct – Nov average. But it shows that the volume loss of 2010 is of the same order as that for 2007, a result that stands for earlier periods during summer. This volume loss is from ice over 2m thick – from analysis of PIOMAS grid box data.

    What I think is happening is that after the clear-out of summer thick ice from PIOMAS in 2010, which also happened 2011, and (due to the same change in seasonal cycle) very probably happened in 2012, the Artic Basin sea-ice has thinned such that open water formation efficiency has increased. This happened in 2010, so the process was ongoing throughout the melt season. But by 2011 and 2012 it was complete and in the CT area anomalies and early summer melt rates, we see the consequences of increased OWFE: record areal melt seasons without anomalous weather driving them.

    No need to reply, sorry to dump all this detail on you but I’m in the process of revising my previously conservative stance on when we’ll see a virtually sea ice free state. So I have all this stuff to hand. FWIW I’m now wondering if Dr Wadhams is correct in saying we’ll see further crashes in the next few years. Up to this summer, and until I saw the detailed PIOMAS data, I had argued against the ‘early transition’ camp.

    Schweiger et al, Zhang et al (a & b) and Perovitch et al support the following broad picture of the processes leading to the losses of 2007: An influx of warm waters through the Bering Strait, driven by the extreme positive Arctic Dipole delivered enough heat to melt 0.5m of ice over the Chucki Sea. That influx of warm waters can itself be attributed to the Arctic Dipole, as the meridional wind anomalies that characterise it are able to draw water in through the Bering Strait (+ve phase) or the Atlantic (-ve phase). The Arctic Dipole also hastened the transpolar drift, transporting large amounts of ice over the Arctic and increasing build up off Canada and transport through the Fram Strait, this lead to the formation of open water in the Pacific sector of the Arctic. This resultant open water, under clear skies, allowed the ice albedo effect to increase absorbed solar radiation by 500%. Schweiger et al find that insolation during June and July did not drive the sea-ice recession at that time, although it did cause thinning of the ice, Perovitch’s study of mass balance buoys finds that insolation (the 500% figure) did cause subsequent warming from August onwards due to open water. As Schweiger et al note “local heating in response to the removal of sea ice is the more likely reason for the increase in temperature” [south of the ice edge].

    However it is not quite as simple as this because the Arctic Dipole itself was both cause and effect. Bluthgen et al use a model forced with observed sea surface temperatures and ice concentrations to study the atmospheric situation in 2007. They find that the initial atmospheric pattern leading to ice loss is reinforced both regionally and due to ice-export acting to intensify the ice loss. So this pattern, the Arctic Dipole, was itself intensified by the sea-ice loss it caused.

    Bluthgen et al, 2011, “Atmospheric response to the extreme Arctic sea ice conditions in 2007.” http://www.agu.org/pubs/crossref/2012/2011GL050486.shtml

    Perovitch et al, 2008, “Sunlight, water, and ice: Extreme Arctic sea ice melt during the summer of 2007.”
    http://imb.crrel.usace.army.mil/pdfs/2008GL034007_for_IMB_web_page.pdf

    Schweiger et al, 2008, “Did unusually sunny skies help drive the record sea ice minimum of 2007?”
    http://psc.apl.washington.edu/zhang/Pubs/Schweiger2008GL033463.pdf

    Zhang et al a, 2008, “The role of Pacific water in the dramatic retreat of arctic sea ice during summer 2007.”

    Zhang et al b, 2008, “What drove the dramatic retreat of arctic sea ice during summer 2007?”
    http://psc.apl.washington.edu/zhang/Pubs/Zhang_etal2008GL034005.pdf

    Comment by Chris Reynolds — 28 Aug 2012 @ 12:22 PM

  88. #83 Douglas McClean,

    During the summer MODIS can be used by analysts to fill the gap in – it has no data hole. It’s not a problem. During the winter the ice will refreeze.

    Comment by Chris Reynolds — 28 Aug 2012 @ 12:30 PM

  89. [edit: off topic]

    Comment by Jaime Frontero — 28 Aug 2012 @ 1:35 PM

  90. [edit: off topic]

    Comment by Wyoming — 28 Aug 2012 @ 2:03 PM

  91. Thanks for the info Chris @88.

    Comment by Douglas McClean — 28 Aug 2012 @ 2:51 PM

  92. Eric [edit: off topic] I wanted to point out here that the MASIE product is specifically bad for trend analysis and that is made clear by the NSIDC. People trying to use it for information on the sea ice’s response to climate change need to RTFM.

    Comment by Unsettled Scientist — 28 Aug 2012 @ 3:12 PM

  93. Douglas:
    NSIDC applies a correction to their area data for the polar hole. It was described last year, but I don’t have a link. AIR they use the ice concentration of the last 1 degree below the hole for the entire hole. I imagine that NSIDC will implement a correction for extent when that becomes necessary (they might already and I have not heard). They are professional in their data analysis.

    What does it matter anyway? When the hole makes a difference the Arctic is ice free.

    Comment by michael Sweet — 28 Aug 2012 @ 3:18 PM

  94. It doesn’t matter, for exactly the reason you mention.

    I didn’t mean to imply that this hadn’t been considered or that anyone was unprofessional; I was just curious.

    Comment by Douglas McClean — 28 Aug 2012 @ 9:13 PM

  95. At Skeptical Science Daniel Bailey posted an interesting graph of 1938 arctic ice extent in August to compare with 2012.

    http://www.skepticalscience.com/news.php?p=2&t=66&&n=1589

    1938 shows lots of arctic ice. I checked some other dates. In 1954 August they show a lot of close drift ice. I am not sure how that compares to the modern version of determining sea ice extent so that there can be a good apples to apples match up.

    http://brunnur.vedur.is/pub/trausti/Iskort/Pdf/1954/

    I read that the current method of filling in grid locations in the arctic is if the ice amount is greater than 15% a grid is considered to be 100% ice. Less than 15% and the area is considered ice free.

    The question is how would the current large area of ice free arctic ocean look compared to the 1954 area?

    Comment by Norman — 28 Aug 2012 @ 9:58 PM

  96. For the “what does it matter folks”, Dr Jennifer Francis has a number of talks available online, including the YouTube:

    http://www.youtube.com/watch?v=RtRvcXUIyZg

    Her C.V.: http://www.whoi.edu/science/cinar/CVs/FrancisJ_CV.pdf

    Comment by Jan Galkowski — 28 Aug 2012 @ 11:30 PM

  97. 93 Michael said, “What does it matter anyway? When the hole makes a difference the Arctic is ice free.”

    The refuge for ice is the Canadian and Greenland coast, which isn’t terribly close to the pole. Will September 2012 area measurements be affected by the hole? Dunno. Do you?

    Comment by Jim Larsen — 28 Aug 2012 @ 11:56 PM

  98. #81, Allen W., 28 Aug, 8:35 AM

    The mouth of the Yukon is ~90 mi south across Norton Sound and another 30 or so miles further south along the coast from Nome. Nowhere is the Yukon’s drainage closer to Nome than around its mouth.

    You are reading about localized phenomena of a week to ten days duration occurring at locations that are exotic to you. To have the effect you seem to want to be possible, they would need to be something like continent spanning and season long.

    Comment by WhiteBeard — 29 Aug 2012 @ 1:03 AM

  99. I just sent letters to my local newspapers announcing this RC article. I recommend you send letters to your local newspapers making the same announcement to get around MSMs reticence. Do not put more than 1 URL per letter and stick to their word limit, probably 200 words. A record ice melt is too visible to be ignored.

    Comment by Edward Greisch — 29 Aug 2012 @ 1:15 AM

  100. The shape of 2012 curve is disquieting. It has not even begun to flatten out. The minimum in 2007 was later than usual, and this year looks to be later yet.

    Comment by SqueakyRat — 29 Aug 2012 @ 2:50 AM

  101. 82: Jaime Frontero: Ok! I apologise for the rather insensitive comment earlier. To a non american (I live in australia), it does appear as though the machinery in your country to downplay important issues and climate change would have to be the biggest, to belittle the whole issue seems to be in hyperdrive. What I am essentially saying is that the top climate scientists should have collabarated with policy makers and the media a long time ago to get them on side before the spreading ‘cancer’ of the denialist lobby could have so effectively strangled the truth which you the climate scientists are continually reporting. Ok! I generalised a little too much but that’s the perception I believe that the outside world has. Take the canadians, they luckily seem have been forgotton by ‘big oil’ and ‘big vested interest’ and their education system has been teaching their future leaders and voting public the uncensored version of AGW and lo and behold their populaces understanding of climate change is one of the world’s best with an corresponding overwhelming majority saying they realise that Climate change is one of the most serious issues facing mankind but more important they realise that humans are behind it.
    And for the record my lifelong heroes you could say have been, Carl Sagan, Jim Hansen and Albert Einstein( well he became american).

    Comment by Lawrence Coleman — 29 Aug 2012 @ 3:04 AM

  102. Re #75 – Comment by Steve Fish — 27 Aug 2012 @ 9:19 PM:

    “News be entertainment.”

    And that’s the problem. We’re not entertaining enough. Entertainment involves drama and conflict. They can get the conflict by putting a real scientist up against the likes of Monckton. Unfortunately, there’s no drama in the scientist dropping his jaw, lost for words apart from “But… but… but…”

    The whole thing needs to be framed as conflict/conspiracy. Pick & mix from:

    1. It’s the Russians. Climate change is warming the tundra while drying out the US grain heartlands.

    2. It’s the Canadians – see (1).

    3. It’s the Muslims. We know they aren’t worried about spending their own people to destabilise the West – extreme flooding in Pakistan, Bangladesh sinking beneath the waves will lead to a tidal wave of refugees.

    4. It’s the Europeans. Those pinkos have been jealous of our freedoms for centuries – they’re trying to hurt our society by wrecking the weather.

    5. It’s the rulers of the New World Order. To reduce overpopulation, they’re setting the planet up for widespread famine.

    Add a catchy title: Weather Wars.

    Job done.

    Comment by Jack Mist — 29 Aug 2012 @ 4:49 AM

  103. The National Ice Center arctic ice extent product says that 2012 is not a record minimum. Can someone explain the difference to the NSIDC product? Thanks!
    http://www.natice.noaa.gov/products/ice_extent_graphs/arctic_weekly_ice_extent.html

    [Response: This is an operational product for people who need to be aware of where any ice might be. It uses whatever data is available and is put together manually. There is no consistency over time in data sources, nor corrections for biases or inhomogenities. Thus it is not very useful for trends - for that you are much better looking at products that use a consistent methodology over time (such as the passive microwave products seen in JAXA, NSIDC and Bremen plots). - gavin]

    Comment by Dan — 29 Aug 2012 @ 4:58 AM

  104. In the six days of record breaking on ice extent. 0.75 million square km have been lost, a rate 2.3 times faster that the average rate in the prior ten years for the same period. http://www.ijis.iarc.uaf.edu/seaice/extent/plot.csv

    Jaw drops….

    Comment by Chris Dudley — 29 Aug 2012 @ 7:11 AM

  105. Oops, should be 0.475 million square km have been lost in six days of records. Typo….

    Comment by Chris Dudley — 29 Aug 2012 @ 7:13 AM

  106. #101–Yes, Canadians are in general better-informed on the GW issue, according to polls. However, that didn’t prevent them from electing a majority Conservative government which IMO is busily enacting a plethora anti-science/anti-environmental measures that the Tea Party can (for the moment at least) only dream about.

    I think that some ‘voter’s remorse’ may be starting to kick in, but Harper & Co. have 4 years left in their mandate, so a there’s a lot more damage ‘in the pipeline.’

    (Full disclosure: I’m a Canadian citizen, living in the US.)

    Comment by Kevin McKinney — 29 Aug 2012 @ 7:55 AM

  107. Lawrence Coleman@101: “Take the canadians, they luckily seem have been forgotton by ‘big oil’ and ‘big vested interest’ and their education system has been teaching their future leaders and voting public ….”
    Your mis-perception of Canada ignores the majority governments aggressive support of the biggest of ‘big oil’ -the tar sands- and the focus of the PM on ‘Northern Development’ made possible [and necessary] by rapid Arctic ice loss. While the media here do a slightly better job of reporting on climate than the US, we also have some of the worst denialators among our academics.

    [Response: Not to get into the politics at all, but an interesting geo-political-economic reality I've come to appreciate only recently is that the race to the Arctic is not really being driven by climate change, nor even "made possible" by it. Certainly, some things are easier and less expensive when there is less sea ice, but economists and industry people I've talked to have said that the cost of oil would have driven things in this direction, regardless of climate change. I find that interesting. We who focus on climate tend to assume that everything gets determined by it, but in the case of the Arctic, the changes we're observed their have apparently more influenced HOW we exploit Arctic resources, rather than determining WHEN we exploit those resources. --eric]

    Comment by flxible — 29 Aug 2012 @ 8:57 AM

  108. Eric, yes and no. To those of us calling for a well-rounded discussion of climate, energy, governance and solutions, what is surprising about your comments is that you seem surprised. This is a whole-system issue. It is literally impossible to understand climate change outside of economic and energy issues. The sources of the rising GHG’s are, after all, anthropogenic. To the extent these issues are treated as separate by various blogging sites, let alone thinkers, progress will remain limited.

    Your contention that it is mostly the “how” that is affected is generally incorrect. Just as the tar sands were not really viable on the scale they are today even five or ten years ago was economic: they are very expensive to produce. Though there has been some innovation in the last ten years, the technology applied to the vast majority of tar sands has been around a long time.

    The price of oil, driven by demand and scarcity of high quality supply, has risen well over 300% from ten years ago. That does drive the need to explore in the Arctic, however, without the melt, it would still be a pipe dream. Don’t let anyone fool you on the tech side: the vast majority of what the public believes to be “new” technology, like fracking, is anything but, and without that melt, Arctic Ocean energy extraction would not be a serious effort right now because it is simply too expensive to build drills and rigs strong enough to withstand the ice, and to also keep personnel safe.

    Climate is driving the how *and* the when.

    I don’t want to derail the general topic here, so for those interested in the energy side of this, there is no better site than The Oil Drum. There is also some climate crossover there with this site often mentioned.

    Comment by Killian — 29 Aug 2012 @ 11:18 AM

  109. >> National Ice Data Center …?
    > [Response: This is an operational product for people who
    > need to be aware of where any ice might be….

    Ships are at risk “where any ice might be” — from chunks of ice in otherwise open water. You know that thing the Titanic hit? It was that sort.

    “… A bergy bit is classified as a medium to large fragment of ice. Its height is generally greater than 1 meter but less than 5 meters above sea-level and its area is normally about 100-300 square meters. Growlers are smaller fragments of ice and are roughly the size of a truck or grand piano….”

    This is explained in detail in their FAQ:
    http://www.natice.noaa.gov/faq.html

    Comment by Hank Roberts — 29 Aug 2012 @ 11:37 AM

  110. To Killian, I’ve got a couple of comments, based on interviews I’ve done with Coast Guard officers, oil industry executives, and academics who study arctic policy.

    Regarding the decline in sea ice and the rise in oil drilling, Shell and others drilled many dozens of wells in the Chukchi and Beaufort Seas in the 1980s and 1990s and it seems clear that they stopped because the price of oil dropped, not because ice inhibited them. Prospecting for oil from the those seas 10 years from now will be easier than it would have been 10 years ago, but the engineering required for production is basically the same: Hugely massive oil platforms or artificial islands, and deeply buried pipes to link the oil to the facilities in Prudhoe Bay. The retreat of summer sea ice seems to be a relatively small factor: No matter what, you still need to build the infrastructure to withstand midwinter conditions and multiyear ice.

    Overall, the process is probably harder now because there’s more regulation and more opposition to drilling than there was a generation ago.

    Shipping is clearly a different story. Quite a few freighters have now traveled through the Northern Sea Route in Russian waters, including some carrying fossil fuels. The Northwest Passage has been slower to open up, but you do see cruise ships and some others passing through there. Traffic through the Bering Strait has climbed very steeply in recent years, a fact that worries the Coast Guard, local residents, and biologists, among others.

    Comment by Jerry Beilinson — 29 Aug 2012 @ 12:39 PM

  111. Do we have a graph of sea ice extent or volume or area extending back a century or 2? We may need to refute the idea that there was less ice way back when. It seems preposterous, given that wooden ships had so little success looking for a Northwest Passage.

    Comment by Edward Greisch — 29 Aug 2012 @ 1:42 PM

  112. 110 Jerry says, “No matter what, you still need to build the infrastructure to withstand midwinter conditions and multiyear ice.”

    pshawh. as if multiyear ice even touches the equation for fossil extraction in the arctic….
    Ice is seasonal and exists for over a year only as a scientific curiosity…

    SO last century…..

    Comment by Jim Larsen — 29 Aug 2012 @ 3:12 PM

  113. 2012 Arctic sea ice minimum, part 2: September 2012 projected at 3.6 million sq km, 700K below previous low in 2007

    In my previous discussion of the extraordinary 2012 melt, I noted the eclipse of the old daily record on August 24, three weeks ahead of the 2007 pace. But I also gave a series of short-term projections for the September extent average, which is the metric typically used to track the decline in Arctic sea ice. The 2012 September projection now stands at 3.56 (+/- .0.13) million sq km, slightly down from my previous projection of 3.67 million sq km. That’s more than 700,000 sq km less than the previous 2007 record of 4.30 million sq km.

    Comment by Deep Climate — 29 Aug 2012 @ 4:04 PM

  114. Here is the one
    http://dotearth.blogs.nytimes.com/2012/08/27/arctic-sea-ice-hits-new-and-early-summer-low-for-satellite-era/
    ” Adrian O
    State College, PA

    Andy, 

Speaking of not knowing, the most mysterious thing for me is that the Arctic melt cycle, recorded around 1820, then 1920-1940 and now 2007-ongoing, has a period of 90-100 years which seems to be completely unrelated to the multidecadal oscillation at a period of about 60 years.

In particular the 1920-1940 melt was in the middle of the warming 1910-1940 while 2005-on melt s in the middle of the cooling 1998-on.
    Aug. 28, 2012 at 2:49 p.m.
    RECOMMEND7″

    Adrian Ocneanu is supposedly a math professor at Penn State.

    Comment by Edward Greisch — 29 Aug 2012 @ 4:27 PM

  115. #111 ” Do we have a graph of sea ice extent or volume or area extending back a century or 2?”

    yesss make that 1100 years in this case:

    http://en.wikipedia.org/wiki/Dorset_culture

    Note the maps, the Dorset culture was maritime based, a coastal people.
    Note where they lived, Always where the ice clears during summer, Now look at the NW Arctic Archipelago, Its a no human zone, despite lands pretty much glacier free.
    If there was a warmer climate like today, there would have been ruins all over the archipelago. There aren’t any. I have further evidence, more detailed with bowhead catches, 17th to 20 th century, the whalers, including American whalers, never went much past Lancaster Sound. Hundreds of hunts by the toughest guys in the world, yet they couldn’t make it due to ice.

    About this subject contrarians have nothing but conjecture to offer, I rather believe in Harry Potter magic than anything they say!!!

    Comment by wayne davidson — 29 Aug 2012 @ 5:20 PM

  116. #107 Eric . Correct, there was a time during the 70′s when oil exploration in the Arctic was driven up by the arab boycott of Israel, they drilled during the most brutal conditions known. There was intense exploration everywhere, in fact there are many capped wells from that time. Ready for export even. The reason why they don’t extract these resources now are market driven.
    Perhaps they wait for the right price,you must ask an economist.

    Comment by wayne davidson — 29 Aug 2012 @ 5:26 PM

  117. @114. Yes, Edward, last time I looked he was indeed at PSU. He’s a pretty hard core denialist; I wouldn’t be surprised to find him on one of those lists of “scientists” who dispute the role of CO2 in climate.

    Comment by Walter Pearce — 29 Aug 2012 @ 5:29 PM

  118. If the use all current knowledge of paleoclimate data – this week milestone may even be first time since Home sapiens start walking on this planet:
    http://les-kar.blogspot.no/2012/08/today-arctic-sea-ice-went-below-4-km2.html

    Comment by Kjell Arne Rekaa — 29 Aug 2012 @ 6:18 PM

  119. Edward Greisch @114 — Could we please avoid copying any of Adrian O’s stuff here? It is quite clear that he is clueless with regard to climatology.

    Comment by David B. Benson — 29 Aug 2012 @ 6:27 PM

  120. Kjell Arne Rekaa @118 — Last time might have been as long ago as the Eemian interglacial (which is, according to some, when Homo spaiens first left Africa).

    Comment by David B. Benson — 29 Aug 2012 @ 7:20 PM

  121. Has runaway GW already begun? Exhibit A, B & C: http://www.iwantsomeproof.com/extimg/siv_ds_anim.gif
    http://www.youtube.com/watch?v=_8bMoAybGno&feature=youtu.be
    http://neven1.typepad.com/blog/2012/08/asi-2012-update-10-at-a-loss.html#more

    Per those animations, it’s easy to see (for those not simply standing their ground, holding a position of denial for political, religious or personal reasons irrespective of data to the contrary) that ice volume is dropping fast?

    Exhibit D: http://arctic-news.blogspot.com/2012/05/striking-increase-of-methane-in-arctic.html

    Per that comparison we can see methane emissions from the Arctic are rising fast.

    Exhibit E: http://newsroom.ucr.edu/1849 ‘Large Release of Methane Could Cause Abrupt and Catastrophic Climate Change as Happened 635 Million Years Ago, UCR-led Study Warns’

    From the article: The researchers posit that the methane was released gradually at first and then in abundance from clathrates — methane ice that forms and stabilizes beneath ice sheets under specific temperatures and pressures. When the ice sheets became unstable, they collapsed, releasing pressure on the clathrates which began to degas.

    Nothing new there, as much has been discussed about methane releasing, as well as positive feedbacks. However, we now need to ask if the thinning ice, (which in spite of less than favorable weather conditions to 07′s melt season is this year exceeding that year’s minimum), acting as a positive feedback. As more ice melts – more methane degasses – with the methane itself acting as the major heat source for accelerated melting.

    Have the scales tipped? Are we now in the throes of runaway GW? Keep in mind people tend to think in very short time periods, so many expect runaway GW to be super fast, but it’s probably more like a train gaining momentum over several Summer melt periods. Once the positive feedbacks reach a certain threshold, the process accelerates much faster, which would account for the loss of Arctic ice exceeding even the most dire projections including this year’s record setting minimum (to be determined later in Sept.).

    Comment by Perk Earl — 29 Aug 2012 @ 8:02 PM

  122. The date when the lowest reaches this year may be later than September 24 recoreded in 2007. Why? The ice extent itself is a cooling syastem. Now that the cooling system has become much smaller, the date can be more likely to the end of next month or even to the beggining of October….

    Comment by Kozo Nagase — 29 Aug 2012 @ 9:27 PM

  123. > Per that comparison we can see
    Do you know the altitude that data set refers to?
    You need to convert millibars to elevation above sea level.
    The same thing has been posted over and over, many places, always with assertions, never with any further support.
    Maybe something will be published — but that isn’t it.

    Comment by Hank Roberts — 29 Aug 2012 @ 9:50 PM

  124. 121: Perk Earl,
    By what I am seeing on the graphs and trend lines I would saw the data is highly consistant with a stable system quicky going into +f/b oscillation. I studied electronics engineering for a number of years and it is always remarkable how relatively little forcing is required to create oscillation. From rest to full amplitude oscillation the decibel graphs follows an exponential curve so starts off at an almost impercepible rate eg. before 1950 and then slowly gains momentum 1990 and now in 2012 it’s getting really obvious and building up a good head of steam. The time to have begun to act on CC was probably in the 1950-60s. In 2012 is looks as though pandora’s box is well and truly open. 1700Gt of CO2 and NO and CH4 in the tundra permafrost and an additional 1400Gt of methane clathrates under the arctic ocean. The powder keg seems set to explode!

    Comment by Lawrence Coleman — 29 Aug 2012 @ 11:06 PM

  125. 121: Perk Earl, I forgot to mention that the speed on onset of the forcing componant determines the energy of the +f/b. Eg. if the rate of CO2 was slowly going up over the last few thousand years in a more or less linear fashion then nature usually has a way of buffering the effect, but this time the incredible rapidity and extent of anthropogenic CO2 onset is unprecedented!. 250ppm, to almost 400ppm now, 100-200 years is unheard of in geological time, that’s like a bullet hitting a pane of glass. You get the picture.

    Comment by Lawrence Coleman — 29 Aug 2012 @ 11:19 PM

  126. I hope the foregoing comment isn’t too big a digression, but the US media’s non-coverage of the record polar ice melt and fires in Spain has been a recurring sub-topic in this discussion. One commenter stated that it is as if the major press is “following” orders, another stated that such a remark was too “tin foil hat” for him. One mentioned the problem is that the media is only interested in news that is entertaining, and the science is too un-entertaining. Another stated that scientists needed to have developed good relations with the media before the “denialists” got to them.

    All these assertions fall short, because they are based on the wrong assumptions about the privately-owned, advertiser-supported media that dominates the US and other industrial nations. So, a few clarifications and facts about the modern media are on order:

    1. The reading/listening/viewing public is not the privately owned media’s customer.

    2. News, information and entertainment is not the product they are selling.

    3. The media’s actual customers are its paying advertisers. For major outlets, these are mostly large corporations – in many cases, subsidiaries of the same corporations that own the media outlets

    4. The media’s actual product is the readers, viewers and listeners. Specifically, their product is people who will be suitably influenced as to be compliant to the advertiser’s business interests, both the narrow interest of buying the advertiser’s product and the broader interests of the industry the business is part of, extending all the way out to include US foreign policy. The reader or viewer must not be made to feel guilty buying cars and burn fossil fuels, nor to oppose business-friendly aspects of US foreign policy, among other things.

    5. Any “firewall” that existed between a media outlet’s business department and its news and editorial rooms has largely broken down over the past few decades. There is a quiet unwritten code among most mainstream journalists that one does not write news stories or analyses that hurt the business interests of the corporate advertisers and owners if one want to advance in their career. I have yet to meet a reporter who will acknowledge such a code exists, but media scholars such as Robert McChesney, Edward Herman, Noam Chomsky, and organizations such as Fairnes and Accuracy in Reporting (FAIR) can find no other consistent and logical explanation for the patterns of news coverage and non-coverage.

    So, no “tin-foil hat” is needed – only an understanding of the things that govern any private business in a competitive environment with powerful customers who can threaten to take their money elsewhere.

    I will leave it to others to find a way for climate scientists to find a way to break-through the corporate media system. But I must warn you that activists in other issues – labor policy, US foreign policy and other environmental issues have had very little luck.

    I refer the reader to the works or Robert McChezney, the public relations and “consent manufacturing” theories (his term) of Edward Bernays, the famous critical work “Manufacturing Consent – The Political Economy of the Mass Media” by Herman and Chomsky.

    Paul D.

    Comment by Paul donahue — 30 Aug 2012 @ 12:33 AM

  127. Edward,

    This paper may help with your inquiry into Arctic sea ice during the past several centuries:

    http://www.dmi.dk/dmi/sr05-02.pdf

    This other oldie, but goodie, describes the mechanism of the multidecadal Arctic oscillation during the latter 20th century.

    http://www.geog.mcgill.ca/gec3/wp-content/uploads/2009/03/Report-no.-1992-17.pdf

    For research going back several millenia, the following has some good analyses.

    http://www.sciencemag.org/content/333/6043/747

    Comment by Dan H. — 30 Aug 2012 @ 6:58 AM

  128. Reply to #126: Great explanation of the media situation. “No tin foil hat is needed”, is right.

    Comment by Perk Earl — 30 Aug 2012 @ 8:15 AM

  129. Post 124: By what I am seeing on the graphs and trend lines I would saw the data is highly consistant with a stable system quicky going into +f/b oscillation.

    Post 125: …the incredible rapidity and extent of anthropogenic CO2 onset is unprecedented!. 250ppm, to almost 400ppm now, 100-200 years is unheard of in geological time, that’s like a bullet hitting a pane of glass. You get the picture.

    LC, very interesting view from an electrical engineering standpoint. Also agree the time to have done something was long ago. What a lot of people do not understand, but I am sure you probably are aware of is the lag time from emissions to its influence on the weather, called thermal inertia. The 30-40 year lag between increased energy in the atmosphere and that energy’s penetration into the biggest holder of thermal energy, the oceans (which drives the world’s weather). To think of the situation in the Arctic in the context of that long a lag time really puts the direness of the situation front and center. The illusion I think many have is, if we decide to really do something about this we can just stop emissions (which is a pipe dream because the economy would falter) in an instant and the problem would go away. Oh wrong, there’s baked in increases for at minimum 30-40 more years. There is no light switch to turn off. I like your bullet hitting the pane analogy – it drives home the idea that once fired it cannot be stopped.

    Comment by Perk Earl — 30 Aug 2012 @ 8:36 AM

  130. Serious question, is it true the antartic sea ice has increased by about 1% a year since satellites have tracked it, if so why the difference with the artic?

    Comment by One Step Beyond — 30 Aug 2012 @ 8:39 AM

  131. Paul #126: I fully agree that the ‘propaganda-model’ of the media by Herman and Chomsky is by far the best explanation of the modern ‘media-logic’. Few journalists recognize or acknowledge this, and neither does most of the public. Once we wake up, maybe we’ll be able to democratize the media so they can paint the full picture on global warming and many other vital topics.

    Comment by Lennart van der Linde — 30 Aug 2012 @ 9:24 AM

  132. @130 OSB: Others here are far more expert, but I’ve heard two relevant points about this– one was that increased melt has led to fresher surface waters which freeze more easily, and the other was that the circumpolar winds which isolate the Antarctic from weather further north have strengthened, slowing warming in the region.

    Comment by Bryson Brown — 30 Aug 2012 @ 9:37 AM

  133. OneStep – No, it’s not true, the rate has been 1% per decade, and the differences from the Arctic are myriad.

    Comment by flxible — 30 Aug 2012 @ 10:00 AM

  134. for “One Step Beyond” — the Antarctic sea ice increase is as predicted:
    WUWT trumpets result supporting climate modelling
    <a href="http://wattsupwiththat.com/2010/03/08/nsidc-reports-that-antarctica-is-cooling-and-sea-ice-is-increasing/&quot; NSIDC Reports That Antarctica is Cooling and Sea Ice is Increasing

    Comment by Hank Roberts — 30 Aug 2012 @ 10:05 AM

  135. One Step Beyond,

    First, the research shows that the increase was 1% per decade, not annually.

    http://earthobservatory.nasa.gov/Features/WorldOfChange/sea_ice_south.php

    Here are a couple explanations by profs. Liu and Trenberth as to why Antarctic sea ice may have grown while Arctic sea ice declined.

    http://news.nationalgeographic.com/news/2010/08/100816-global-warming-antarctica-sea-ice-paradox-science-environment/

    Comment by Dan H. — 30 Aug 2012 @ 10:16 AM

  136. Re: #127 (Dan H.)

    It’s misleading to characterize Arctic sea ice by two papers focusing only on very limited regions — one on east Greenland, the other on north Greenland.

    Instead one can find a 1450-year reconstruction for the whole Arctic in Kinnard et al. (2011). It looks like this:

    An even longer-term view can be found in Polyak et al. (2010).

    And if one wants graphs of the last century and more, download the Walsh & Chapman data set. It gives plots like this:

    [edited for images]

    Comment by tamino — 30 Aug 2012 @ 11:52 AM

  137. This discussion makes it sound like ALL Antarctic ice is increasing. The Antarctic Peninsula is warming and the Larsen ice shelves are disappearing. Due to warm water currents other ice shelves are melting at various locations in other parts of that vast continent. I would not be at all surprised that some ice in some locations is growing and I for one prefer to get my information from actual experts on the Antarctic ice shelves and Antarctic glaciologists who make repeated visits in order to make sense of an obviously complicated system.

    Comment by M Tucker — 30 Aug 2012 @ 12:10 PM

  138. Kozo (#122)

    Using the JAXA data, we can find the time during the last nine years when the ice extent loss rate was as large as during this last week of daily records. On average that was 17 days earlier than now. From the last period at the current rate of loss in those earlier years to the minimum of each year was on average 33 days, though it can happen in as short as ten days. Sigma, estimated from the sample variance is 12 days. So, just based on phenomenology, there seems to be a fairly good chance that this year’s minimum will happen in October. And, we have not really started the 33 day turn around clock either.

    Comment by Chris Dudley — 30 Aug 2012 @ 12:21 PM

  139. From The Carbon Brief:

    Two new research papers published today improve our understanding of the planet’s methane emissions, and might raise worries about the role of the gas in warming the planet. The first suggests that there may be extensive methane deposits under the Antarctic ice sheets. Meanwhile, the second concludes that emissions of the gas from Arctic permafrost have been underestimated.

    Comment by SecularAnimist — 30 Aug 2012 @ 2:20 PM

  140. Interesting that everyone is going gaga over the ice cube/km2 count while PIOMAS indicates that the show was over 2 months ago.

    Comment by cowichan — 30 Aug 2012 @ 2:42 PM

  141. Cowichan, you misread the PIOMAS _anomaly_ chart. See the earlier posts explaining that to me, among others. Early on in the past few years more ice goes away than did historically. The difference is the ‘anomaly’ — bigger earlier. By this time of year the _anomaly_ is not as big.

    Comment by Hank Roberts — 30 Aug 2012 @ 3:47 PM

  142. cowichan @140
    The 2012 PIOMAS volume has yet to reach its minimum as the year-on-year graph of PIOMAS volumes [I edited this because it looked like a dubious site -- please clarify]> here (usually 2 clicks to ‘download your attachment’) which is data generated up to this August 25th (or there abouts).

    Comment by MARodger — 30 Aug 2012 @ 5:48 PM

  143. Re:PIOMASS

    verified by ICESAT,Cryosat
    sets August record

    graphs from Wipneus at Neven’s site

    https://sites.google.com/site/arctischepinguin/home/piomas/piomas-trnd6.png
    https://sites.google.com/site/arctischepinguin/home/piomas/piomas-trnd2-1.png

    fat lady sings in 2015 +3/-2

    sidd

    [Response: Hmm.. What justifies using an exponential fit? --eric]

    Comment by sidd — 30 Aug 2012 @ 6:01 PM

  144. Re: PIOMASS, exponential fit

    i have no justification for a mechanism where the ice loss goes as the exponential trend fitted. A straight line thru the last decade gives similar result. A hyperbolic tangent would probably do the same. I claim the graph argues for the min volume drop to effectively zero _within the noise range_ of +/-2e3Km^3 around 2015. And from the physical standpoint, I see no mechanism that can stay ice loss from the heat load from the ocean, or the albedo flip, the graph is telling us how fast it is going, how fast these processes can work.

    sidd

    Comment by sidd — 30 Aug 2012 @ 6:33 PM

  145. I am wondering why is all the ice melting? When you look at the historical summer temps in the Arctic region, 2012 does not stand out as a well above normal warm one.

    http://ocean.dmi.dk/arctic/meant80n.uk.php

    From looking through the different years, Arctic summer air temperatures do not seem unusually warm. Why do years like 2007 and 2012 have such large ice melts even though the temperatures in the area is not above the long term normal?

    Comment by Norman — 30 Aug 2012 @ 7:17 PM

  146. #145 Norman, excellent proof of a cloudy summer, exactly cloudy, with IR reflected back up and down from sea ice to clouds. SST’s are for the larger part much warmer, another good reason to melt the ice.

    Comment by wayne davidson — 30 Aug 2012 @ 8:24 PM

  147. Re: #145 (Norman)

    First: the DMI temperature data you linked to is not what it appears to be. It’s not measurements, it’s the output of computer models. More important, it’s the output of different computer models for different years, and those models have an inherent bias between them which makes them not really comparable. That’s the main reason that those who deny the reality of global warming like to reference it so often.

    Second: if you want a decent perspective on how Arctic temperature has changed, look at this.

    Third: a great deal of melting happens from below (due to warmer ocean temperatures) rather than above (due to warmer air temperatures).

    Bottom line: 2012 is “well above normal warm,” the Arctic has warmed. A lot.

    Comment by tamino — 30 Aug 2012 @ 8:48 PM

  148. Tamino at 147,

    Thanks for the link to the Arctic temp graph. The problem with this graph is it is for yearly temps. Unless broken down to summer melt months it could just indicate much warmer winters, which would still be several degrees below freezing. It may not be evidence that the summer temps really are much warmer than before.

    Here is an older article that you have probably seen:

    http://climatescienceafrica.blogspot.com/2009/11/less-dusty-from-africa-warms-tropical.html

    This one explains the reason the North Atlantic has warmed so much in the last few decades. This warmer north atlantic water does move into the Arctic ocean via ocean currents and could explain the rapid melt of summer ice since the 1990′s. The article may be correct as other ocean basins are not heating as rapidly.

    Comment by Norman — 30 Aug 2012 @ 9:17 PM

  149. #145 additional, DMI might be off for the summer but closer to reality during winter. It was a very warm Arctic winter, thus ice thickness not building up so much,

    Comment by wayne davidson — 30 Aug 2012 @ 9:25 PM

  150. Several people: Thanks for your help.

    Comment by Edward Greisch — 30 Aug 2012 @ 9:41 PM

  151. I just posted the following message at the White House website.

    The GOP platform criticizes President Obama for describing climate change as a severe threat. I hope that President Obama speaks very forcefully about this in his acceptance speech at the Democratic convention on September 6.

    The NSIDC has recently announced that arctic sea ice extent has shrunk to a record level. The PIOMAS updated estimate for arctic sea ice volume might be released early enough in September to be included in the acceptance speech, also. The decline in volume is even more dramatic than the shrinking of arctic sea ice extent.

    The threat posed by climate change and extreme weather is highlighted by the impact of this year’s drought and heat on agricultural production. The United States military has described climate change as an “accelerant of instability and conflict.”

    Comment by John Kintree — 30 Aug 2012 @ 10:05 PM

  152. sidd @143 & 144 — One might begin with the
    http://en.wikipedia.org/wiki/Logistic_function
    to develop a justification (of a crude4 sort) for the exponential nature of the fit.

    Comment by David B. Benson — 30 Aug 2012 @ 10:22 PM

  153. [Response: Hmm.. What justifies using an exponential fit? --eric]

    Well, when scientists have NO CLUE what sort of fit is appropriate, the fit that fits reality best is by definition the default fit. So, Eric, either provide some evidence that the exponential fit is wrong, or….

    [Response: We discussed this before. Exponential fits don't have any basis in physics, and don't even give the smallest residuals. No model simulation indicates that an exponential fit is a good prediction - even when you know the answer! No peer reviewed paper has supported this with any, err... actual evidence. So, no, the burden of proof is not on those who don't think this is justified, but rather is on those who seek to persuade others it is justifiable. - gavin]

    Comment by Jim Larsen — 30 Aug 2012 @ 10:32 PM

  154. Gavin,

    Thanks for the response, and I accept that I’m likely wrong. “Denialism” is rampant both on the low and high side.

    Comment by Jim Larsen — 30 Aug 2012 @ 11:28 PM

  155. Thanks for the explanations re the antartic, appreciated

    Comment by One Step Beyond — 30 Aug 2012 @ 11:34 PM

  156. Norman this should help with a few of your questions

    http://www.skepticalscience.com/print.php?r=288

    Comment by john byatt — 31 Aug 2012 @ 1:48 AM

  157. Norman @145/148

    Further to Tamino @147, the DMI graph you link to is produced for air temperatures above 80ºN. That bit of the Arctic still remains essentially ice-covered. Indeed, this year of dramatic melt it is about the only bit remaining ice-covered. That is why the temperature tends to hover where it does.
    When I witnessed Lindzen using these DMI graphs at the talk he gave in the Palace of Westminster a few months back (he actually shuffled them up so even a proper sequence of yearly graphs was not presented), it spurred me to produce some arctic temperature graphs to illustrate the warming that Lindzen said didn’t exist.

    Arctic air temperatures essentially the graph linked @146 but also showing winter & summer anomalies since 1979.
    Monthly Arctic air temperatures since 1979.
    Monthly sea-surface temperatures for Arctic & for above 80ºN The lower trace is thus the SST for the area in the DMI air temp graphs.
    (Note usually 2 clicks to ‘download your attachments’)

    Comment by MARodger — 31 Aug 2012 @ 3:20 AM

  158. I’ve been drawing simple bar graphs that track the minimum ice extent, area or volume for each year to date. With the PIOMAS August update (through 8/25) the results are striking:

    http://img.photobucket.com/albums/v224/Chiloe/12_Climate/sea_ice_PIOMAS_min_to_date.png

    Comment by L. Hamilton — 31 Aug 2012 @ 6:13 AM

  159. Gavin said :

    Exponential fits don’t have any basis in physics

    I am just an amateur, and I think you are right that an pure exponential fit has no physical basis.

    However, I did put my money on the reasoning that there is a physical basis for the observed non-linear decline at least until ice area gets really small :
    http://scienceblogs.com/stoat/2011/06/26/betting-on-sea-ice-10000/

    My reasoning goes as follows, and I would love to hear your opinion on where this reasoning goes wrong (if anywhere) :

    1) Assume that starting ice volume (thickness*area) is the same each year, and assume a given amount of heat during summer that melts ice to a certain minimum extent at the end of the season. During freezing season, that volume grows back to same volume it started with the year before. So system is in equilibrium.
    Now if due to some external forcing, like planetary GHG forcing or ocean current heat, the amount of heat input during the melting season starts to increase linearly, then we would expect the minimum ice area at the end of the melting season to reduce linearly as well. That’s the first order.

    2) Of course, ice-water albedo feedback will kick in during the melting season, which means a second order term appears in the ‘minimum ice area’ function.

    3) Now, if the negative feedback during freeze-up (lower ice insulation leads to faster ice growth) is not as large as the positive feedback in (2), then next year ice will be thinner. Warmer winters don’t help restore original volume here. That means that (1) will progress faster, which leads to the third order term.
    Note that PIOMAS results suggest that year-over-year ice volume declined linearly by 400 km^3/year over the past 30 years. This means that (3) is certainly present, although most volume reduction so far was in thick MYI. So we did not see this third term expressed in sea ice area/extent reduction…until this year ?

    4) Finally, and likely most important : possibly due to the same external forcing in (1), summer snow cover (over land) starts to reduce rapidly, especially over the past decade :
    http://nsidc.org/arcticseaicenews/files/2012/07/Figure5a.png
    Since albedo effect is largest in June, when the sun is brutal in the Arctic, snow-albedo effect should be much larger than ice-albedo effect in (2) :
    For example, in June, 60 deg North the record 6 million km^2 in June suggests something like a 1000 TW heat input anomaly on the land directly bordering still pristine Arctic sea ice. If even 25 % of that heat causes ice melt, then snow anomaly in June 2012 alone will cause a 2000 km^2 ice volume anomaly w.r.t. year 2000.
    Since that heat entered early in the melting season, this heat goes right back into (1), for further amplification.

    Models seems to support a soft landing more or less like a Gompertz curve, and that is how most smaller water basins melt out (such as Hudson Bay). So I think models are going to be proven correct qualitatively.

    But so far, PIOMAS still shows loss of volume (despite a harsh winter) and thus we do not seemed to have reached the soft landing part of that Gompertz curve yet…

    So AFAIK the question is thus not if there is a physical basis for a near-exponential decline (there is), nor if Arctic sea ice extent decline follows that function (it does so far), but the question is when (which sea ice area minimum, and over which timeframe) and how will it ‘land’ and what will happen after that ?

    Comment by Rob Dekker — 31 Aug 2012 @ 10:10 PM

  160. MARodger @ 157

    Thanks for the graphs. They do show a warmer temperature in the summer as well that would cause greater ice melt.

    I was doing more research on this topic.

    This link provides information on Arctic Warming from 1920-1940.
    http://mclean.ch/climate/Arctic_1920_40.htm

    From Skeptical Science posted by Daniel Bailey @83 he provides a graphic of Arctic ice in 1938 compared to 2012.
    http://www.skepticalscience.com/news.php?p=2&t=83&&n=1589

    If you compare August 1919 to August 1980 they are fairly close, both are during cold times in the Arctic.
    http://brunnur.vedur.is/pub/trausti/Iskort/Pdf/1919/
    http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/ARCHIVE/19800830.png

    Taking in all this information and then looking at this graph of the North Atlantic temperatures.
    http://i52.tinypic.com/72yjwj.jpg

    It may be possible that a warmer North Atlantic water temp is responsible for a lot of the Arctic melting and the warmer Arctic temperatures.

    Then there is this article to consider.
    http://www.eurekalert.org/pub_releases/2008-01/du-naw010308.php

    Comment by Norman — 31 Aug 2012 @ 11:03 PM

  161. Typo : replace “2000 km^2 ice volume” by “2000 km^3 (2000 Gton) ice volume”.

    Also, I did not want to single out Gavin for a response.
    Please feel free to shoot down my explanation of why Arctic sea ice decline is on a near-exponential decline, still pointing at near-ice-free conditions in summer in a few years.

    Also, please let us know what you think would happen with excess heat in the Arctic after a seasonally ice free ocean is common. Will it simply raise ocean temperatures ? Will ice free conditions expand quickly to August and July (or October and November) ? And how much will it enhance Greenland ice sheet melting ?

    While we are at it, does anyone know of a study that shows why glacial/inter-glacial cycles did NOT occur until CO2 levels declined to some 300-400 ppm during the late Pliocene (3 million years ago) ?
    http://en.wikipedia.org/wiki/File:Five_Myr_Climate_Change.svg

    Could it be that the positive feedbacks in the Arctic that I mention above (snow albedo, ice albedo, ocean temperature forcing on sea ice) are strong enough to prevent a 40 W/m^2 insolation drop to create a glacial period ?
    If so, then why would we think that a similar small forcing would not knock out the remainder of Arctic sea ice ? And what would prevent us from going back to that late-Pliocene climate, and corresponding sea levels ?

    Comment by Rob Dekker — 1 Sep 2012 @ 12:44 AM

  162. Mr. Dekker: Right now we are all amateurs. Looking at PIOMAS noise variation shows there is approx 1e21J heat sloshing yearly around the icepack. Seasonally gone in a decade to within the noise.

    Now consider Prof. Box estimate of 1e20J extra from albedo flip in GRIS this July, and his argument as to erosion of “cold content.” And the fact that, as attested to by many (Nansen for example, Mr. Lewis on this blog more recently,) that warm ice flows much better than cold.

    What will happen when the ocean has no more ice to melt ? A hard rain gonna fall on GRIS every warmth. Ablation line going up, ice surface going down. What will it do ? GRACE will tell the sad tale.

    sidd

    Comment by sidd — 1 Sep 2012 @ 1:32 AM

  163. > what will happen

    The End of a Glaciation”
    Focus September 2012 Volume 5 No 9 pp585-674

    “… the transitions from glacial maximum to interglacial conditions generally occurred over about 10,000 years. In this web focus, we present a collection of overview, primary research and opinion pieces that explore the links between solar radiation, ice-sheet melting, ocean circulation and climate that govern the transition from glacial maximum to interglacial warmth….”

    “… Past transitions from glacial to interglacial climates have not been smooth. It would be wise to prepare for similarly sudden episodes of ice loss in future climate changes.”

    Comment by Hank Roberts — 1 Sep 2012 @ 6:26 AM

  164. #145 et seq.: It’s interesting to line this development up against natural influences. While we are higher in the solar cycle than in 2007, the current solar cycle is still one of the lowest on record. 2007 was a cooling year in the ENSO cycle, whereas this year we’re had a bit of the El Niño phase of the cycle, but not a strong one. There isn’t anything to suggest from this that any natural influence should be causing unusual warming. Next time the solar cycle goes back to its more usual maximum or next time we have a strong El Niño 1998-style, we could see a very rapid loss of sea ice extent.

    However: we should be careful of looking for instantaneous connections.

    What we are seeing this time is most likely the effect of long-term loss of multi-season ice depth that doesn’t in the short term decrease sea ice extent, but results in needing a year that’s not exceptionally above the norm to drive back ice area a long way, once the multi-season ice has thinned enough. GISS shows northern hemisphere summer is one of the warmest on record, but not the warmest. Local Arctic conditions could also be warmer (I can’t find data specific to that on a quick search), but you wouldn’t expect this much ice to go away all at once. Arctic sea ice volume is another trend you should relate to sea ice extent.

    Comment by Philip Machanick — 1 Sep 2012 @ 9:02 AM

  165. Have been reading in sections of the media that the Arctic ice loss is due to a natural cycle of ocean currents, and something similer happened in the 1930′s. What is the background to this?

    [Response: It's true that there was Arctic warming in the 1920s and 1930s, and this was noted in the records of the time, but the losses of sea ice pale in magnitude compared to what is being seen now. I suggest that you compare any specific mentions of some change in a part of the Arctic with maps from today - there is a huge difference. - gavin]

    Comment by DP — 1 Sep 2012 @ 9:29 AM

  166. #81, Allen W., 28 Aug, 8:35 AM

    To continue walloping a point with more info, here’s further follow up on heavy rain along the eastern coast of the southern Chukchi Sea. The accompanying photo, taken on the 25th, is probably worth a click just for novelty by anyone.

    http://www.thearcticsounder.com/article/1235flood_plagues_region

    Comment by WhiteBeard — 1 Sep 2012 @ 10:01 AM

  167. Norman @160
    Your first link I have recently visited (spurred by the John Christy garbage) & was less than impressed by the bit that I was interested in – Russian Northern Sea Route shipping. The link says that the 1930s have to have been less icy than the early 1900s because the shipping using the N.S.R. in the 1930s contrasts with the likes of the St Anna in 1912 that was caught in ice & carried off into the central Arctic.
    Most of the specific assertions are iffy enough to ring loud alarm bells. And I was amused to read elsewhere that, like the St Anna, the Russian icebreaker Sedov was caught in ice in 1937. Two other breakers with her were rescued but the Sedov was carried off into the central Arctic, eventually being resucued only in 1940 when the Russians sent the biggest icebreaker they had to free her.
    I note that the denialosphere has now picked up on some of these statements in the link with the icebreaker Sibiryukov now sailing the salty seas round North of Severnaya Zemlya in 1932 with narry a whiff of any dynamite useage to shift all the ice.

    Comment by MARodger — 1 Sep 2012 @ 10:33 AM

  168. Judging from the configuration of the sea ice extent right now, The Gulf Stream may go more northward,the sinking point also moving northward.
    The final scenario I thought up is The stream stops sinking in The Arctic Sea, instead goes through Bering Strait to The Pacific.
    The situational evidence looks looming. In the last winter,SIE covered the strait on a two decades ago basis.
    My guess is the stream pushed SIE forward toThe Pacific.If realized, global oceanic current system would change drastically.

    Comment by Kozo Nagase — 1 Sep 2012 @ 10:38 AM

  169. How long has it been since the last time arctic sea ice extent-area-volume were as low as they are now? How long has it been since the last time the Arctic ocean was ice free? Is there a link to a good reference on that?

    Comment by John Kintree — 1 Sep 2012 @ 11:42 AM

  170. Thanks everyone for pointing out “anomaly”. Two months ago we were 4 standard deviations below trend, 4!!, and no-one thought it worthy of mention.
    If you’ve been at all interested in Arctic ice conditions lately you would have read of ships cruising through 2 meters of “ice” without the crash and bang of ice breaking because the “ice” was the consistency of a slushy. When a floating slushy is agitated by stormy seas is it any wonder that it disappears?

    Comment by cowichan — 1 Sep 2012 @ 12:35 PM

  171. > ships cruising through 2 meters of “ice” without the crash

    Help me out here, as Google hasn’t been able
    to find a source for that, for me, today.

    Where’d you learn about that?

    Comment by Hank Roberts — 1 Sep 2012 @ 3:47 PM

  172. PS for Cowichan
    > two months ago

    The June anomaly was mentioned in widely read sources, for example, here:
    http://nsidc.org/arcticseaicenews/2012/07/rapid-sea-ice-retreat-in-june/

    Comment by Hank Roberts — 1 Sep 2012 @ 3:52 PM

  173. #165, DP. If there was a warming in the Arctic it was not extensively measured due to lack of weather stations especially on the North American side of the Arctic. However a good way to judge the sea ice melt would be to look at end of August 1938 extent map as recorded by DMI

    http://brunnur.vedur.is/pub/trausti/Iskort/Pdf/1938/1938_08.pdf

    and compare with end of august Cryosphere today:

    http://arctic.atmos.uiuc.edu/cryosphere/NEWIMAGES/arctic.seaice.color.000.png

    As it all melts the tides-current and dominant winds eventually force the ice to ridge to the Greenland North American sid. In effect, more observations from the Russian side basically show a vast area of ice still present and surviving till the beginning of the 21st Century.

    Comment by wayne davidson — 1 Sep 2012 @ 3:57 PM

  174. Kozo Nagase @168 — First heck the volumetric constraint on currents through the Bering Strait. It is narrow and shallow.

    Comment by David B. Benson — 1 Sep 2012 @ 4:48 PM

  175. John Kintree @169

    This link comes from the answer question page of the National Snow and Ice Data Center that produces the graphs used in many arctic climate studies.

    The ice may have been less than today about 5500 years ago.

    “Based on the paleoclimate record from ice and ocean cores, the last warm period in the Arctic peaked about 8,000 years ago, during the so-called
    Holocene Thermal Maximum. Some studies suggest that as recent as 5,500 years ago, the Arctic had less summertime sea ice than today. However, it is not clear that the Arctic was completely free of summertime sea ice during this time.”

    http://nsidc.org/arcticseaicenews/faq/#summer_ice

    Comment by Norman — 1 Sep 2012 @ 10:38 PM

  176. The ice may have been less than today about 5500 years ago.

    So? You do understand that the current human population is orders of magnitudes greater than then?

    Or are you suggesting that since, in the past, natural causes dominated, that today, our CO2 emissions don’t? That would be lame, surely you’re not *that* lame, are you?

    And, of course, our main worry is going forward … as things are shaping up, we’re going to blow out any semi-recent comparisons right out of the water in the next few decades.

    Comment by dhogaza — 1 Sep 2012 @ 10:57 PM

  177. Question
    http://www.nature.com/ngeo/journal/v5/n9/full/ngeo1528.html

    Why did glaciers not cover Siberia? Or is it just not shown?

    =======

    Question
    “[T]he Laurentide Ice Sheet residing in the Hudson Bay marine basin collapsed”

    “However, once the Laurentide Ice Sheet became predominately marine-based over Hudson Bay during TI, it underwent a relatively rapid reduction in area5, 74, 75 (Fig. 5e), analogous to a lagged-nonlinear response.”

    So “collapsed” doesn’t mean all in one day? “Collapse” is such a dramatic word to use instead of “melt.”

    I see that the authors of the article are working on the second question.
    “For the lagged-nonlinear model, the Barents-Kara Ice Sheet may have taken several millennia to fully collapse63, 64, 65, 66, a significantly longer period than present concerns over future eustatic sea-level rise98. However, the final collapse of the marine portion of the Laurentide Ice Sheet at ~8.2 kyr ago occurred in less than 130 years and raised eustatic sea level 0.8–2.2 m75, which is a timescale of more importance to global society98.”

    Comment by Edward Greisch — 2 Sep 2012 @ 12:20 AM

  178. Some studies suggest that as recent as 5,500 years ago, the Arctic had less summertime sea ice than today.

    Begging the question, when was “today?”

    Comment by dbostrom — 2 Sep 2012 @ 1:05 AM

  179. In the holocene optimum, insolation in the northern hemisphere was much higher in summer, as earth was in its perihelion then at this time. This has been abundantly pondered on in this blog. That we see similar conditions with the opposite orbital forcing is quite remarkable, and not a good reason to downplay things in lukewarmer lingo.

    Marcus

    Comment by Marcus — 2 Sep 2012 @ 3:05 AM

  180. Sidd said :

    Mr. Dekker: Right now we are all amateurs. Looking at PIOMAS noise variation shows there is approx 1e21J heat sloshing yearly around the icepack. Seasonally gone in a decade to within the noise.

    Sidd, climate models seem to indeed project a steep decline in Arctic sea ice extent, but actual ice losses are now 4 sigmas (SD’s) below model projections. This seems to suggest that the Arctic in reality is much more sensitive than IPCC model projections indicate.

    [Response: This is no longer true. See Stroeve et al referenced above. - gavin]

    Some scientific papers suggest that “internal variability” of Arctic climate is responsible for the larger-than-expected drops in ice extent.
    And these may indeed be right, but there comes a point where the probability of “internal variability” as the cause of sea ice decline is no longer statistically reasonable, and we would have to look at other causes, such as snow albedo effect and ice-thinning due to warmer ocean currents, and the 4th order ice reduction function I suggested in post 159.

    Incidentally, does anyone have any data on the snow anomaly that is projected in GCM simulations, and if this anomaly even remotely resembles the actual snow anomaly in June 2012 of 6 million km^2, which adds an extra 1000 TW into the melting season ?

    Comment by Rob Dekker — 2 Sep 2012 @ 3:11 AM

  181. The putative warming imbalance of the planet is 0.9W/sq.m of 145E20 Joules/year.

    Arctic sea ice reduction accounts for about 1E20 Joules/year – 1/145th of the planet’s supposed energy gain or 0.7%.

    This is from a surface area inside the Arctic circle (66 degN) of about 4% of the Earth’s surface.

    Could someone explain why we are so worried about the Arctic rather than any other 4% patch of the Earth’s surface?

    Comment by Ken Lambert — 2 Sep 2012 @ 8:28 AM

  182. dhogaza @176

    I was not making any suggestions with my reponse. I was answering questions from John Kintree @169. He asked for some links on past ice cover and I provided him with them.

    Comment by Norman — 2 Sep 2012 @ 9:48 AM

  183. Rob Dekker@180
    Regarding Snow Cover projections from models. AR4 give figures from Chapter 6 of ACIA which ACIA break down into quarterly anomalies for 2071-2099 (fig 6.5 p200). Given the spectacular anomalies of early summer in the last few years graphed here (usually 2 clicks to ‘download your attachment’), the projected end-of-century figures do suggest an underestimation (in a similar way to sea ice). So far winters have been getting snowier which masks the annual averages, but the summer snow cover is the factor for the fragile Arctic climate. This year’s MAM anomaly was -2.2, about a third of the max projected for 2100 & this year’s JJA anomaly will probably exceed the max end-of-century projection!
    AVERAGE SEASONAL ANOMALIES (M sq km)
    SEASON . ACIA AVE . (ACIA MAX) . 2010-2012
    DJF . . . . . . -3.8 . . . . . . . . . (-5,8) . . . . . . +1.7
    MAM . . . . . -4.9 . . . . . . . . . (-6.8) . . . . . . . -1.8
    JJA . . . . . . .-1.1 . . . . . . . . . (-3.2) . . . . . . . -2.6
    SON . . . . . . .-3.3 . . . . . . . . . (-4.6) . . . . . . . +0.7

    It’s a bit of untold Northern drama that I came across just a few weeks ago.

    Comment by MARodger — 2 Sep 2012 @ 10:05 AM

  184. 178 dbostrom: Good point Doug. There seems to be persistent interest in 5500 YBP, various interglacials, the PETM, you name it. Here’s the problem with that: we don’t live in the PETM, or whenever else. We live here and now and this is the only climate we’ve got. The world’s societal and agricultural infrastructure has developed in response to the climate we have (or perhaps more appropriately, used to have…) . It’s worth repeating the closing statement from the recent AMS Climate Change Statement: Prudence dictates extreme care in accounting for our relationship with the only planet known to be capable of sustaining human life.

    Comment by Tokodave — 2 Sep 2012 @ 10:19 AM

  185. > Norman says:
    > … I was not making any suggestions …. I was answering questions …. He
    > asked for some links on past ice cover and I provided him with them.

    Well, you provided him with some, but not particularly recent ones.
    He presumably wanted sources from current science.
    Beware answering by copypasting references you find elsewhere in blog argument.
    Often the same stuff is “cited” over and over to spin the discussion.

    Use Scholar, limit your search to recent work, look for papers that have been cited frequently and articles that review the field.

    Or use Google with the same search terms;

    You’ll find things like this:
    http://anthro.palomar.edu/homo/images/map_of_glaciations.gif
    from http://anthro.palomar.edu/homo/homo_3.htm

    Comment by Hank Roberts — 2 Sep 2012 @ 11:46 AM

  186. Confusing for some but fascinating for most here at RC is this map:

    http://www.esrl.noaa.gov/psd/map/images/rnl/sfctmpmer_01a.rnl.html

    even without a great deal of ice the sea surface temperatures appear mostly normal over open water, but warmer over what is left of sea ice.

    Again as I predicted and always wrote: its because of the clouds:

    http://www.weatheroffice.gc.ca/data/satellite/hrpt_dfo_ir_100.jpg

    So much clouds that the average temperature during the last 30 days:

    http://www.esrl.noaa.gov/psd/map/images/fnl/sfctmpmer_30a.fnl.html

    Appears totally Normal over the Arctic Ocean even during the entire melt season:

    http://www.esrl.noaa.gov/psd/map/images/rnl/sfctmpmer_90b.rnl.html

    The warmest air was over the area where the ice resists melting. Meaning that there is an interesting exchange going on between open water and the near permanent cloudy Arctic ocean sky. I will have a refraction based analysis soon on this, lets see what the sun disk has to say about this.

    Comment by wayne davidson — 2 Sep 2012 @ 11:59 AM

  187. Rasmus: thanks for posting your R code. I tweaked it a tad so I could see the text in a smaller scale and took out the background in my response to all this. Short summary: sea ice can go fast if you don’t pay attention to volume and only look at area.

    And we mustn’t forget that about 90% of warming goes into the ocean, and not too big a shift in where ocean heat content ends up could make a big difference to sea ice.

    Comment by Philip Machanick — 2 Sep 2012 @ 1:55 PM

  188. @Gavin

    I don’t see how your response to the following is supported by Stroeve et al.

    >>
    Sidd, climate models seem to indeed project a steep decline in Arctic sea ice extent, but actual ice losses are now 4 sigmas (SD’s) below model projections. This seems to suggest that the Arctic in reality is much more sensitive than IPCC model projections indicate.

    [Response: This is no longer true. See Stroeve et al referenced above. - gavin]
    >>

    The appropriate quote from abstract:

    Trends from most ensemble members and models nevertheless remain smaller than the observed value. Pointing to strong impacts of internal climate variability, 16% of the ensemble member trends over the satellite era are statistically indistinguishable from zero. Results from the CMIP5 models do not appear to have appreciably reduced uncertainty as to when a seasonally ice-free Arctic Ocean will be realized.

    Another paper, by Maslowski et al. (2012) states:

    The inability of climate models to adequately reproduce the recent states and trends of Arctic sea ice diminishes confidence in their accuracy for making future climate predictions. Another issue is that sea ice extent and area are parameters that only partially account for the loss of sea ice volume. An unrealistic sea ice–thickness distribution will affect the modeled ice extent and area as well as volume, which in turn may delay (or accelerate) predicted changes in seasonal sea ice cover in the Arctic Ocean. This fact emphasizes the need for detailed analyses of changes in sea ice thickness and volume to determine the actual rate of melt of Arctic sea ice.

    By the way, in the earlier discussion of the ice free Arctic you (the group) concluded

    It is possible that this analysis will change the predicted timing of the “ice free summers” but large uncertainties will likely remain. Until then, we believe, we need to let science run its course and let previous model-based predictions of somewhere between “2040 and 2100″ stand.

    Are you entirely sure, that when the reality is more and more divergent from the models, it should be wiser to stick to data, instead of trusting the models?

    [Response: You are over interpreting what I said, and your last statement is a completely nonsensical statement. That might sound a little harsh, but think about it for a minute before responding. There are two issues here: a purely factual one related to whether the CMIP5 models show a spread of declines that encompass the observed decline - and in agreement with my statement above - they do. Second there is the issue of how to make predictions in the light of the observed trend and spectrum of model results and infinite possibilities for statistical projections. Since we do not have any observations of the future (yet), any projection must require a model of some sort. There is no projection that just 'follows' from the observations absent some statistical model of the underlying behavior, hence your dichotomy is nonexistent- the only choice you have is in deciding what models you want to pay attention to and on what basis. - gavin]

    Comment by pohjois — 2 Sep 2012 @ 3:04 PM

  189. Could someone explain why we are so worried about the Arctic rather than any other 4% patch of the Earth’s surface?

    Because quite a lot of research suggests that weather over much of the northern hemisphere is heavily influenced by that little patch at the top of the planet. You probably already knew that but what the heck, a rhetorical Hail Mary in a tight spot might be distracting to a few people.

    I used to think I wouldn’t care when I went bald. The reality proved different to what I imagined might happen as I followed my genetic heritage. What I didn’t realize was how much worse it would be to have a wee little bald patch surrounded by a generous tonsure; changes the whole look of things, quite disproportionate to area. :-)

    Comment by dbostrom — 2 Sep 2012 @ 3:07 PM

  190. An empirical equation for arctic sea ice volume:

    V — Annual average sea ice volume
    V’ — Rate of change of V

    Somewhere somebody posted a link to a paper which contained phase diagrams (V on the horizontal axis and V’ on the vertical axis) derived from several different GCMs projections to century’s end. The general shape of these diagrams gives rise to a particular equation for

    V’ = f(V,dT/dt)

    where dT/dt is the rate of change of arctic (surface air) annualized average temperature. We take dT/dt = k (approximately 0.053 degrees Celcius per annum).

    Now clearly V’=0 when V=0 but also V’=0 when the Arctic Ocean is full of ice (any overflow leaving via Fram Strait is ignored). Let m denote the maximum sea ice volume.

    The resulting equation (to approximately match the phase diagrams) is

    V’ = kV(V-m)

    which integrates to a qubic equation for V.

    Statistican George Box said words to the effect that all models are wrong but some are useful. This model is presented to stimulate discussion.

    Comment by David B. Benson — 2 Sep 2012 @ 5:37 PM

  191. Followup From #186 , Satellites seem OK, http://eh2r.blogspot.ca/ , it is not an anomaly, malfunction or misread, the arctic atmosphere appears to have an “average” temperature. More reading will reconfirm.

    Comment by wayne davidson — 2 Sep 2012 @ 5:50 PM

  192. {Oops. An oversight, apologies.]

    The integrated solution is

    V = m/{exp(kmt)-1}

    which is much more interesting.

    Comment by David B. Benson — 2 Sep 2012 @ 5:57 PM

  193. Ken Lambert:

    Could someone explain why we are so worried about the Arctic rather than any other 4% patch of the Earth’s surface?

    Ken’s asked this question elsewhere. Maybe he’s hoping to get an answer he likes better here. Nah, he’s probably just trolling.

    Comment by Mal Adapted — 2 Sep 2012 @ 5:58 PM

  194. Jim Larsen: “Well, when scientists have NO CLUE what sort of fit is appropriate, the fit that fits reality best is by definition the default fit.”

    Uh, no. There are other criteria, as well. Otherwise, the “model” would change any time you had a fluctuation. Simplicity (which corelates to predictive power) and physical reasonableness are also important criteria.

    An exponential fit simply is not reasonable, as the amount of sea ice lost would have to be proportional to the amouth of sea ice lost in the recent past. For an exponential fit to have a chance, YOU would have to show us at least a plausible argument for why dx~axdt.

    Comment by Ray Ladbury — 2 Sep 2012 @ 6:40 PM

  195. Ken Lambert,
    The answer to your question is that this 4% of the planet has an outsized influence on the climate of much of the northern hemisphere, has very high abedo at present that will decrease dramatically once the ice melts, And has so damn much carbon under the ice that if it is realesed, for all practical purposes its “GAME OVER”. That help?

    Comment by Ray Ladbury — 2 Sep 2012 @ 6:44 PM

  196. That’ll confuse everybody: my 5:57 pm comment is to correct my 5:37 pm comment (which is still in moderation).

    Comment by David B. Benson — 2 Sep 2012 @ 7:57 PM

  197. Is there some common defining characteristic for the models that do roughly correspond to observed decline rates. For example, in these models, can we compute the oceanic heat flux across say the 70th or the 80th parallel to see if the ‘better’ models transport more heat into the Arctic icecap ?

    sidd

    Comment by sidd — 2 Sep 2012 @ 9:29 PM

  198. MARodger,
    Thank you very much for your post at Neven’s on the “untold drama” of snow cover anomalies.

    Since snow cover anomalies happen when the Arctic sun is brutal (May/June/July), as opposed to ice cover anomalies (which tend to maximize in August/September, when the strength of the sun is much reduced) and they affect a larger are than ice cover anomalies, it seems that snow anomalies are the 600 pound gorilla in the room that few talk about.

    Also thank you very much for the link to the AR4 model projections for snow cover anomalies. It seems odd to me that the simulated snow cover anomaly in May, using AR4 models, is lower than the anomaly in June.
    Basic physics of polar amplification would suggest that if the May anomaly is X, that the June anomaly would be larger than X. After all, when snow disappears at some latitude, the albedo difference should cause a significant additional forcing to occur, which should make the snow anomaly at higher latitude larger, as long as insolation is larger.

    Does anyone know if there is a paper that explains why the MAM snow anomaly in AR4 models is smaller than JJA snow anomaly ?
    Which physical effect could be responsible for that inconsistency ?

    Comment by Rob Dekker — 3 Sep 2012 @ 2:44 AM

  199. Gavin, with all due respect, but I think that “pohjois” and “sidd” have a point.

    You are correct that Stroeve et al 2012 show that “the CMIP5 models show a spread of declines that encompass the observed decline – and in agreement with my statement above – they do”.

    Still, Dr. Stroeve explained on a different blog (where people are not by far as nice as here) the following caviats :

    This paper compares the next round of climate models with the observations. They better represent the mean state of the ice cover than the models in 2007 IPCC report, and they also generally simulate faster rates of decline, though many are still slower than observed. Interestingly though is that the uncertainty as to when an ice-free Arctic may be realized remains about the same in the earlier models.

    Such statements, combined with the statement in the abstract :
    http://www.agu.org/pubs/crossref/2012/2012GL052676.shtml

    Trends from most ensemble members and models nevertheless remain smaller than the observed value. Pointing to strong impacts of internal climate variability, 16% of the ensemble member trends over the satellite era are statistically indistinguishable from zero. Results from the CMIP5 models do not appear to have appreciably reduced uncertainty as to when a seasonally ice-free Arctic Ocean will be realized.

    seem to suggest that Stoeve et al suggests that we are simply still running in a ‘low’ probability area of the CMIP5 simulations. In other words, this (below 4 million km^2) 2012 minimum may still be an artifact of “internal variability”, albeit at a low probability curve…

    Now, Stoeve et al may be right or not, but at least is that a correct summary of what Stroeve et al 2012 are telling us ?

    If this is the message from Stoeve et al 2012, the question that emerges is : how high is the probability is that reality is indeed a artifact of “internal variability”, and that thus a “recovery” may be imminent ?
    And how high is the probability that this trend is NOT due to internal variability ?

    And how do we know if it is, or is not ?

    What is the probability that the decline of Arctic sea ice is NOT a result of internal variability, but in fact a result of high sensitivity of the Arctic to small forcing perturbations, such as what Maslowski’s models project ?
    And what is your opinion on other papers, such as Massonnett et al 2012, who state :

    http://www.atmos.washington.edu/~bitz/massonnet_etal_GRL_SUBMITTED.pdf

    We identify a
    nonlinear relationship between the mean September sea ice extent (SSIE) and the trend in SSIE over the same climatic
    (30 yr) periods, characterized by an elevated rate of decline when the SSIE reaches 2-4 million km2

    Would that not suggest that we have just entered a timeframe where Arctic sea ice is susceptible to “elevated rate of decline” ?

    Thus, when you say “your dichotomy is nonexistent- the only choice you have is in deciding what models you want to pay attention to and on what basis.” would it not be rational to pay attention to Maslowski’s models, and to address the physical basis of a 4th order polynomial decline in Arctic sea ice as I suggested in post 159 ?

    Comment by Rob Dekker — 3 Sep 2012 @ 3:29 AM

  200. whether the CMIP5 models show a spread of declines that encompass the observed decline – and in agreement with my statement above – they do. Second there is the issue of how to make predictions … There is no projection that just ‘follows’ from the observations absent some statistical model of the underlying behavior, …. – gavin]

    Yep, we know you guys are hot on the trail and will eventually nail sea ice loss to within natural variability, and will be able to predict or explain the results of that variability to great accuracy. We also know that current models’ median runs underestimate sea ice loss to the extent that multiple papers have been published noting it, with one using that fact as the lead, even separated by white space and worded like a newspaper headline. You can understand how that doesn’t bestow confidence in short term results of current models.

    So, when scientists are essentially saying that reality is 2-3(?) sigma off median, and those same scientists were saying a few years ago that reality is 4(?) sigma off (as always, counting data through today), then I’ve got to wonder if you guys are “there” yet. Anything over 1 sigma maintained for many years is a serious red flag unless it is explicitly explained. If one can’t explain natural variability after it happened, then one’s model isn’t done yet.

    I would love to see median runs for current models, as well as 3 sigma low runs (how many runs are done?). I’m guessing 100% of the readers here would also love it. Then we would know what you mean by “encompass”. if one model’s lowest run matched reality, I wouldn’t be convinced the models were reasonable representations yet, especially if reality’s “input variables” didn’t match the low run’s randomly generated inputs.

    Science strives for bottom-up solutions, as that’s the way to get to “proof”. But humans are designed for top-down thinking. Calculating the distance a ball will fly when propelled by a complex mechanism of bone and tissue is near impossible for nearly anybody except an average math-illiterate kid.

    10 years ago I top-down figured the ice would be essentially gone (below 1) by 2020, so I made a bet on 2025. Perhaps the residual ice pack will be larger than the bet’s arbitrary definition, but the appropriate “model” to use is often the most complete one, and currently I’m guessing that no computer model can “throw an ice ball” as well as the one we were born with – not a simple fit/extrapolation, but a holistic solution which includes things like scientists’ personalities in the analysis.

    You said exponential fits have no basis in physics. OK, but they sure can be approximations for results caused by multiple linear forcings which are seasonal and were/will be initiated at different times and act on different variables (area, volume, flow rate, etc), especially when the need for accuracy ends with such a large ice pack (1 at minimum).

    As I said before, I accept I’m likely wrong – but my wallet is feeling pretty comfortable right now.

    Comment by Jim Larsen — 3 Sep 2012 @ 5:33 AM

  201. The melting of ice is a clear indication that the planet is warming, so I want to ask about an article that was supposedly published in “Nature Climate Change” (see the address at the bottom of the page) that claims tree rings prove it is getting colder. I am wondering if this is not the real “Nature Climate Change” because the link is a little different than the real Nature Climate Change site. The article is posted on a site that posts conspiracy theories about climate change, AIDS, and other scientific topics, so I wondered if something wasn’t right.
    http://www.omsj.org/reports/esper%202012.pdf

    On this article at the bottom of the page it says it is from Nature Climate Change, but the Internet Address is a bit different than the homepage of the Nature Climate Change that is affiliated with Nature.

    The article is too difficult for me to evaluate, but the OMSJ site is posted on posts attacks on climate science and even articles by John O’Sullivan.

    Can you look at this and explain to me what is going on?

    Comment by Snapple — 3 Sep 2012 @ 8:39 AM

  202. I have found what seems to be this article on the real Nature Climate Change site.
    http://www.nature.com/nclimate/journal/vaop/ncurrent/full/nclimate1589.html

    I guess I am now wondering if someone will explain to me why this conspiracy site is posting this article. Is it supposed to prove that Dr. Mann is wrong?

    Comment by Snapple — 3 Sep 2012 @ 8:46 AM

  203. Here is a description of the tree ring article on the OMSJ site, which posts a lot of conspiracies. Maybe they have not accurately described the main point of the article. After all, most people wouldn’t be able to understand this article.

    http://www.omsj.org/issues/global-warming/scientists-calculate-global-cooling-trend#more-4779

    Comment by Snapple — 3 Sep 2012 @ 9:14 AM

  204. I have had a busy summer and missed some things, and I now see that RC discussed this paper. RC doesn’t agree with all of the paper, but thinks the paper makes some good points. the paper is being cherry-picked by denialists to undermine Dr. Mann.

    Comment by Snapple — 3 Sep 2012 @ 9:51 AM

  205. @ Snapple
    http://www.realclimate.org/index.php/archives/2012/07/tree-rings-and-climate-some-recent-developments/

    Comment by Pete Dunkelberg — 3 Sep 2012 @ 10:13 AM

  206. Thanks PD–I found that post and the discussion at Skeptical Science.

    Comment by Snapple — 3 Sep 2012 @ 12:28 PM

  207. Here’s a bit more refined update to my PIOMAS visualization of the evolution of Arctic Sea Ice volume.
    Latest data was Aug 26th 2012 – I’ll redo when September’s figures become available.
    http://www.youtube.com/watch?v=bNkyJ7eHHhQ

    Comment by Andy Lee Robinson — 3 Sep 2012 @ 1:21 PM

  208. Here is the citation for comments 190 & 192:
    The trends in summer Arctic sea ice extent are nonlinearly related to the mean sea ice state in CMIP5 models
    F. Massonnet, T. Fichefet, H. Goosse, C. M. Bitz, G. Philippon-Berthier, M.
    M. Holland & P. -Y. Barriat
    GRL, submitted
    http://www.atmos.washington.edu/~bitz/massonnet_etal_GRL_SUBMITTED.pdf

    Finally, the concluding equation ought to have a constant of integration, K, which allows setting t=0 arbitrarily:

    V = m/{exp(kmt+K)-1}

    Comment by David B. Benson — 3 Sep 2012 @ 5:09 PM

  209. In the past we focused on sea ice extent simply because it was more easily and accurately measured, even as “everybody” acknowledged that volume was the better measure of the structural health of the ice.

    Now, volume measurement has become cheap and accurate enough to be used, but ironically at a time where volume might be becoming less important than extent. Now, functional health of the ice, as in albedo and weather maintenance, could be more important than structural health.

    Comment by Jim Larsen — 3 Sep 2012 @ 9:51 PM

  210. 188 pohjois said, “Are you entirely sure, that when the reality is more and more divergent from the models, it should be wiser to stick to data, instead of trusting the models?

    [Response: ... and your last statement is a completely nonsensical statement....gavin]”

    Yes, but his intent is blatantly obvious. Typos happen.

    Poh, great info and logic, but debating with someone who has lots more data is frustrating, eh? Ya gotta cobble together bits – such as your 16% of runs gave 0 trend. If the runs which encompassed reality also are 16% of runs, then the models are off by perhaps 100% (or 50%, depending on if you’re talking half or double) This gels with Cyrosat-2 news.

    http://beforeitsnews.com/environment/2012/08/esa-cryosat-2-data-reveals-arctic-summer-sea-ice-loss-50-percent-greater-than-expected-2445390.html

    Comment by Jim Larsen — 3 Sep 2012 @ 10:42 PM

  211. Man what a goof. Driving down the wrong side of the road. It’s 50% only.

    Comment by Jim Larsen — 3 Sep 2012 @ 10:55 PM

  212. David B. Benson,
    I think you confuse “Non-linear”, as denoted in Massonnet et al, with “exponential” as in your expression.

    Please remember that there does not seem to be any physical reason for “exponential” decline. A quadratic, or even up till 4th polynomial decline seems to have physical merit, while a pure “exponential” decline does not, as Gavin pointed out earlier.

    Needless to say that even a quadratic decline matches the initial part of a Gompertz curve that would be expected for a system in terminal decline with a “soft” landing, similar to what GCMs project for the future of Arctic sea ice, with the caviat that the time line on which this decline happens seems to be much shorter than the models project.

    Comment by Rob Dekker — 5 Sep 2012 @ 4:30 AM

  213. Jim Larsen,
    You are making assumptions about Stroeve et al 2012.
    Why don’t you read the paper before you draw conclusions ?

    Comment by Rob Dekker — 5 Sep 2012 @ 4:33 AM

  214. And may I add that you seriously overestimated the probability that the 2012 September minimum falls within the CMIP5 simulation window as presented by Stroeve et al 2012.

    Comment by Rob Dekker — 5 Sep 2012 @ 4:41 AM

  215. Snapple @ 201–I did not read the whole article, but note that they talk about “strong forcing at -0.31 oC per 1000 years. This goes along with the data showing that the earth’s climate was slowly cooling until recent, human-caused changes. The trends that the paper talks about are longer term and much weaker than more recent changes.

    Comment by BillD — 5 Sep 2012 @ 5:28 AM

  216. “Why don’t you read the paper before you draw conclusions ?”

    I read every link on this and the other thread. Now, if those didn’t include Strove – as if I’d remember the name – or if the links were to the “free” stuff like abstracts and what you request is paywalled, then I can’t comply. So yep, I did it or nope, I “can’t”.

    And I never draw conclusions – just current barely-informed opinions while whining for more info (oops, here comes one) like my oft-repeated whine about not seeing current ice-loss model results, especially driven by actual real weather.

    Comment by Jim Larsen — 5 Sep 2012 @ 11:38 AM

  217. And, to emulate your double-post :-) I was flailing and trying to find out what Gavin meant by “encompasses”. The number was totally fake, as I thought I made clear. I’ll be more diligent at putting (?) after such numbers.

    And the spread of models, from no ice loss at all to reality’s exponentialesque decline (call it quadratic, call it what you like, tis all the same, as any definition is by definition just a visualization of a happenstance fit), well, it throws up a red flag. Looking at reality, since 1990 PIOMAS minimum volume estimates have never risen for three years. Since we know each year’s ice is mostly an independent event (outside of thick multiyear ice, which is fast becoming extinct), the consistent decline really brings into question the models’ incredible swings between runs.

    Comment by Jim Larsen — 5 Sep 2012 @ 11:58 AM

  218. We’re now below 4m sq km – http://nsidc.org/arcticseaicenews/

    Comment by Guy Rowland — 5 Sep 2012 @ 4:44 PM

  219. Here’s one for communicating the science, with special reference to the Arctic Sea Ice: http://www.upworthy.com/the-one-where-the-weather-lady-freaks-out-on-live-tv?g=2
    You might be wise to put you r coffee mug down before hitting ‘play’.

    Comment by MalcolmT — 5 Sep 2012 @ 5:23 PM

  220. Reply to Guy of post 218. Currently looks like it’s at 3600, over 1/2 a million square kilometers less than the 07 record melt. Might go as low as 3300. Just think of it – 1st time below 4 and we may end up at 3300?

    reply to 219: That was a great video! Really liked the part at the end when the anchor tries to change the subject to a famous couple ‘Kanoodling’ and she shoves him off his chair. Maybe this is what the deniers in DC need to get it.

    Comment by Perk Earl — 5 Sep 2012 @ 11:35 PM

  221. Gavin

    I have tried to response few days ago, but the comment didn’t get through and mail contact failed as well. So I will try to put my answer in parts, hopefully this will help to avoid spam filter.

    Regarding the first issue, I have no access to the Stroeve et al. so I
    can only take your word for that, which is more than sufficient.
    Nevertheless authors stress that Arctic ice predictions based on these
    models are “highly uncertain”, which in plain words means “of little use”.
    And this leads straight to the second issue – in the next comment.

    Comment by pohjois — 6 Sep 2012 @ 4:24 PM

  222. Part 2.
    When the uncertainty of estimates based on GCM models is so high, then the estimates based on simple trends observed in data should be treated as a reasonable alternative, and this is what I call sticking to data.

    This should apply in particular when these empirical models are accompanied by a reasonable argument why the GCM models are biased towards slower melt. People working with Arctic ice argue that this is due to low spatial resolution of sea models in GCMs leading to overestimates of ice thickness (Maslowski et al 2012).

    Comment by pohjois — 6 Sep 2012 @ 4:28 PM

  223. Part 3.
    And sticking to data:

    - the volume of Arctic ice as estimated by PIOMASS has reached this year 3.6 thousand km3,
    - the largest volume loss recorded at minimum in PIOMASS was 3.5K km3, and recently twice (2007 & 2010) the volume loss was 2.5K km3,
    - the average yearly ice loss since 1997 is 0.6K km3 (albeit with a very high standard deviation).
    Don’t you think that prediction of practically ice free Arctic (ice extent below 1M km2) before 2020 is at least equally reasonable as between 2040 and 2100?

    Comment by pohjois — 6 Sep 2012 @ 4:31 PM

  224. Rob Dekker @212 — Thank you, but

    V = m/{exp(kmt+K)-1}

    is not exponential in the sense used in a much earlier comment. Also, looking at the phase diagrams derived from model runs in the Massonnet et al. submission led me to the line of reasoning which gives the above formula.

    Note that the formula implies that the annual average sea ice volume will never become zero despite dT/dt=k continuing indefinitely. This might suggestion the original approximation to the phase diagrams is overly simplistic.

    Moreover the above formula is concave while the diagrams for the sea ice extent suggest a convex curve. (It would be helpful if someone used the existing data to determine the annualized average sea ice volume as a function of year.)

    Comment by David B. Benson — 6 Sep 2012 @ 7:29 PM

  225. Stroeve et al 2012 can be found here (open access for me):
    http://www.agu.org/journals/gl/gl1216/2012GL052676/2012GL052676.pdf

    Comment by Daniel Bailey — 6 Sep 2012 @ 7:47 PM

  226. 225 Daniel, that link goes to the AGU sign-on screen for me. My guess is you’re a member and so get to see information which, though probably 100% taxpayer funded, is not visible by mere taxpayers.

    We’re ever so lucky to have the 1%. Otherwise, we’d have to settle for paying a penny or two for information, when now we get to pay a far superior $20 plus the penny.

    Comment by Jim Larsen — 6 Sep 2012 @ 10:18 PM

  227. On 225, scientists, please please please include wording similar to “and inform the public through a free or extremely cheap conduit” to your grant proposals. Publishing in a peer-reviewed journal is just a requirement, not a good thing. The good thing is publishing a free or nearly free version of your results.

    Comment by Jim Larsen — 6 Sep 2012 @ 10:34 PM

  228. > 100% taxpayer funded

    But whose?

    Authors Kattsov and Pavlova are at the Voeikov Main Geophysical Observatory, Roshydromet, St. Petersburg, Russia, though the others are at US gov’t labs.

    Now I agree with you that the information ought to be more easily available (I assume you’ve looked via Scholar, which often lists the freely available copies along with the paywalled copies? If not, do make the effort.

    But yes, the AGU comes in for criticism about its publishing.

    To quote Some guy in Japan on that point: “… It’s a shame that the AGU hasn’t taken the opportunity to do something more radical with its recent reorganisation of its publications. Hooking up with a conventional profiteering toll-access publisher (and one with some fairly unsavoury activity in its recent history) is I suppose the easy option for a bunch of conservative greybeards, but I can’t help but think of it as a missed opportunity….”

    Yep.

    Comment by Hank Roberts — 7 Sep 2012 @ 12:25 AM

  229. This Stroeve & Barrett presentation may help the discussion above.
    Versions of the p10 graphic have been doing the rounds but the p9 one for instance I’ve not seen elsewhere.

    Comment by MARodger — 7 Sep 2012 @ 2:52 AM

  230. Jim Larsen,
    In the case of Stroeve et al 2012, I purchased the paper for $25.
    That’s not going to break the bank, but I agree with you that it is an obstacle for free exchange of up-to-date scientific info.

    Now. I do not know how much I am allowed to say about the paper, but I assume that my opinion on the paper is allowed.

    For starters, it seems to me that the analysis (of CMIP5 models on Arctic ice extent) it better than the 2007 CMIP3 results, but again is already behind reality.

    The 2012 mega-melt (some 3.6 M km^2 minimum) is in the fringes of the CMIP5 GCM results. It’s about 2 sigma’s below the mean of the ensemble runs, and if I interpret the plot correctly, the only model runs that showed a minimum as low as we will get in 2012 are the model runs that start off with an unrealistically small ice extent in the 80′s to begin with.

    So, Jim, your point was much stronger than you presented it to be. That’s why I told you to read the paper first before making your point. Sorry I came across a bit harsh.

    The more interesting part of the paper is what I think is what is NOT mentioned in Stroeve et al 2012 :

    - There is NO analysis of ice volume (scalar or field) development in the models (except for a mention that volume analysis will be done later).
    - There is NO mentioning at all about snow cover (snow anomaly) analysis, and certainly not if the observed massive snow anomalies from the past decade (including the record 6 million km^2 snow cover anomaly in June 2012) are even remotely replicated in the CMIP5 models.
    http://nsidc.org/arcticseaicenews/files/2012/07/Figure5a.png
    - There is not a single mention about ocean heat flux. Of course there is a real problem in validating ocean heat flux, but at least it would be nice to see what the simulated water temperatures are for the main influxes of ocean heat via Fram Strait and the Bering currents. We know that Fram Strait ocean water increased significantly over the decades, and we know that ocean heat flux seriously inhibits growth of thick ice during winter. Which in turn significantly affects ice volume.
    So can we at least get the results of ocean heat influx from the CMIP5 models and how that compares to observations ?

    In my opinion, the lack of GCM model results for ocean heat flux and spring/summer snow cover anomalies presented in scientific papers of IPCC model runs, as well as what seems to be a consistent underestimate of Arctic sea ice melting rates, makes GCM analysis papers like Stroeve et al 2012 much less interesting than they could be.

    Would it be possible to present such information in the “supplemental material” ?

    Meanwhile, the Arctic sea ice model that seems to gain more and more respect is PIOMAS.
    Time and again, it’s results match observations very nicely (submarine measurements, ICEsat, Cryosat 2 etc), maybe because it’s focus is so much on Arctic sea ice. I wish there was a snow-cover module and a ocean heat flux module that would be as accurately simulating reality as PIOMAS is for sea ice.

    Combining best-in-class modules with GCMs, we should be able to get at least a more accurate estimate of the expected response “trend line” of Arctic sea volume/extent given a GHG forcing source trend line, and how much “natural variability” really can divert from that trend.

    Until then, I agree with ‘pohjois’ that PIOMAS volume data by itself is the best volume data we have, and since year-after-year volume is still declining (even still accelerating), we should seriously consider an early melt-out to near-ice-free Arctic summers in this decade as a likely scenario (maybe even the most likely scenario).

    Comment by Rob Dekker — 7 Sep 2012 @ 3:26 AM

  231. Based on revised JAXA date, yesterday marked a fortnight of consecutive record ice loss. In the first half of that period, the ice extent loss rate was enormous compared to the prior ten years, sitting at 3.4 sigma above the mean. During the second half, the ice extent loss rate is not unusual. It ranks one above the median in the last 11 years (including this one). All of the ten prior years turned around in September, not October. 2007, the year with the latest turn around of this group ranks one below the median in ice extent loss rate for this period between Aug, 30 and Sept. 6.

    http://www.ijis.iarc.uaf.edu/seaice/extent/plot.csv

    Comment by Chris Dudley — 7 Sep 2012 @ 7:14 AM

  232. Rob (#230),

    PIOMAS does well matching observations because it incorporates a lot of observations in the calculation. It is not a climate model based prediction.

    Comment by Chris Dudley — 7 Sep 2012 @ 7:25 AM

  233. Speaking of PIOMAS, and update through Sept. 2 is now available. http://psc.apl.washington.edu/wordpress/research/projects/arctic-sea-ice-volume-anomaly/

    Comment by Chris Dudley — 7 Sep 2012 @ 9:19 AM

  234. Re- Comment by Jim Larsen — 6 Sep 2012 @ 10:18 PM:

    You say- “Publishing in a peer-reviewed journal is just a requirement, not a good thing.”

    I agree with your concern about the results of publicly funded research not being made more available to the public. However, you got this bit backwards. Actually, publishing in a peer reviewed journal is not a requirement but it is a good thing. Perhaps a typo?

    Steve

    Comment by Steve Fish — 7 Sep 2012 @ 11:41 AM

  235. Another POW:

    The Arctic Ocean used to be another continent when it was frozen over all year. A witry continent with many peculiar attributes, but a continent nevetherless. It should not have been modeled as an ocean.

    World under the ice cover is very different also.

    The ice gone, it becomes a part-time real ocean. Unlinear dramatic change.

    Comment by Pekka Kostamo — 7 Sep 2012 @ 1:39 PM

  236. Of possible interest: updated cycle plots showing sea ice area and extent changes for every month of the year (24 statistically significant downward trends), from November 1978 through August 2012.
    http://img.photobucket.com/albums/v224/Chiloe/12_Climate/2012_Cycle_Arctic.png

    Discussion of the plot at Neven’s Sea Ice blog:
    http://neven1.typepad.com/blog/2012/09/cycle-plots-of-sea-ice-area-and-extent.html

    Comment by L Hamilton — 7 Sep 2012 @ 2:29 PM

  237. Apologies if this has already been posted.

    asl.umbc.edu/pub/yurganov/methane/YurganovCCL.pdf

    Takeaway line (for me, at least):

    “The main conclusion of this paper is a qualitative detection of high and over the years increasing methane mixing ratios in areas coinciding with predicted locations of methane hydrates.”

    Sounds like pretty good evidence that methane hydrate release has begun and is accelerating. The main question now is what is the rate of accelerate, and will that rate be further increased by a newly ice-free (or nearly so) Arctic Ocean.

    Note that CT Arctic sea ice area continues to plunge–now at 2.298 million k^2.

    http://arctic.atmos.uiuc.edu/cryosphere/arctic.sea.ice.interactive.html

    Comment by wili — 8 Sep 2012 @ 11:34 AM

  238. > qualitative detection
    means “I can smell it but not tell you how much there is”
    http://regentsprep.org/Regents/math/ALGEBRA/AD1/qualquant.htm

    Comment by Hank Roberts — 8 Sep 2012 @ 1:30 PM

  239. Exactly. As I said, it is the exact amount (quantity) of acceleration of release that has yet to be accurately determined. Are any excursions up in that direction now investigating this?

    Comment by wili — 8 Sep 2012 @ 3:27 PM

  240. 234 Steve Fish said, ” Perhaps a typo?”

    That’s a nice way of putting it, and essentially correct, too! :-) Instead of “a good thing”, I should have typed ” “the” good thing” (including quotes). Of course, both are/would be good things. And, as Hank pointed out, things get complicated in a global community.

    Thanks for the data and analysis, Rob. Your $25 was well-leveraged. Ho-hum weather (at least above the ocean’s surface) giving 2 sigma results (and your initial conditions point as well) doesn’t convince me that the models are ready for prime time. I’ve long thought of it as a race between nature and scientists. Will nature get to ice-free before scientists can predict it via models?

    Here’s a 5 page article about weather forecasting and models. Forecasters get attuned to models’ quirks and adjust their forecasts accordingly. For example, it mentioned that certain events tend to cause the models to predict rain about 100 miles too far south(?), so they forecast rain further to the north.

    Interestingly, on page 4 it says, “weather is nonlinear, meaning that it abides by exponential rather than by arithmetic relationships.”, which seems to contradict the expert consensus on RC.

    http://www.nytimes.com/2012/09/09/magazine/the-weatherman-is-not-a-moron.html?_r=1&src=dayp

    Comment by Jim Larsen — 8 Sep 2012 @ 8:49 PM

  241. #235, I really liked what Pekka wrote,:

    “The Arctic Ocean used to be another continent when it was frozen over all year. A witry continent with many peculiar attributes, but a continent nevetherless. It should not have been modeled as an ocean.

    World under the ice cover is very different also.

    The ice gone, it becomes a part-time real ocean. Unlinear dramatic change.”

    So true about the other continent bit, In Arctic Canada there are 2 huge Territories, one is called Nunavut, by the ancient most beautiful language of Inuit. Nunavut literally means “our land” , by extension Arctic straits, channels even Huge Hudson Bay becomes land by sea ice, land animals, wolves , Hares, foxes and Caribou called tuktu cross it as land.

    But Pekka, Inuit elders saw the change coming a long time before I did, it was quite linear.. Very slow slow change now becoming obvious by all the blue water.

    Comment by Wayne Davidson — 8 Sep 2012 @ 9:42 PM

  242. A run of fifteen consecutive new records for lowest ice extent seems to have ended yesterday. More records may still be coming, and the data may be revised further. 2007 saw a couple of long streaks past the 9/22/05 prior minimum in the JAXA data set, one of 17 days starting 8/15/07 and one of 14 days starting 9/3/07.

    Comment by Chris Dudley — 9 Sep 2012 @ 6:06 AM

  243. IS THERE A WAY OUT?

    If we were to terminate all fossil fuel use today, the temperature increase over pre-industrial due to what we have burned already would be about 3 C. This arises from 0.8 C experienced already, about 0.7 C to be realized from CO2 in the atmosphere whose temperature consequences have yet to be realized because of lag time, and an equal increase from elimination of the fossil sulphates that have been placed in the atmosphere from fossil fuel combustion and effectively increase the albedo.

    This ignores any feedbacks, and especially methane release. We know from recent expeditions that large increase in Arctic methane emissions have been observed. Because of the potential importance of the methane contribution to temperature increase, we should be tracking methane releases continuously throughout the Arctic, ranging from near-seafloor to space. Yet, from what I have been reading, methane data is extremely sparse. We need to be blanketing the Arctic with methane and other GHG sensors; the present lack of effort is inexcusable.

    But, even without major feedbacks, the 3 C temperature increase we have ‘built-in’ from past combustion is catastrophic. From all that I have read, this level of increase without feedbacks will produce an effectively unlivable environment for perhaps billions of people. Also, from what I have read, there is little chance that temperatures would stabilize, given the observed existence of feedbacks. So, the unrealistic goal of terminating fossil fuel use today will still result in an unlivable environment. Given the decades more of fossil fuel use that faces us in reality, the unlivability will only be compounded. Is this problem solvable in theory and, if so, is it solvable in practice?

    Comment by Superman1 — 9 Sep 2012 @ 11:23 AM

  244. Apologies if this has been posted here before, but here is this rather lengthy posting by Professor Peter Wadhams of Cambridge:

    “In a January 4th post on “Real Climate”, David Archer addressed those who are raising concerns about the speed of ice loss in the Arctic and the resultant potential for warming water temperatures to thaw frozen methane and release it as gas to the atmosphere. In essence, he dismissed such concern as a form of unfounded alarmism making “much ado about nothing”. In this rebuttal, I would like to respectfully challenge this dismissive stance and assert that severe dangers are arising in the Arctic which call for the full attention of humanity.

    The present thinning and retreat of Arctic sea ice is one of the most serious geophysical consequences of global warming and is causing a major change to the face of our planet. A challenging characteristic of the behaviour is that both the rate of retreat (especially in summer) and the rate of thinning in all seasons have greatly exceeded the predictions of climatic models. The sea ice cover of the Arctic Ocean, particularly in summer, has been in retreat since the 1950s at a rate of about 4% per decade which has recently increased to 10% per decade. More seriously, the thickness of the ice has diminished.

    Satellites can track ice area, but ice thickness distribution is most accurately measured by sonar from underneath the ice. Since 1971, I have been going to the Arctic in UK nuclear submarines, mapping the ice thickness using upward-looking sonar along the vessel’s track. U.S. submarines have also allowed such availability. Opening these submarines to scientific work has been a marvellous service to climate research. It was thanks to submarines that I was able to show for the first time that the ice in the Arctic is thinning (in a 1990 paper in Nature [2], showing a 15% thickness loss in 11 years), and recent work from UK and US submarines now shows a loss of more than 43% in thickness between the 1970s and 2000s, averaged over the ocean as a whole [3]. This is an enormous loss – nearly half of the ice thickness – and has changed the whole appearance of the ice cover. Most of the ice is now first-year rather than the formidable multi-year ice which used to prevail.

    The thinning is caused by a mixture of reduced growth in winter (because of warmer temperatures and more heat in the underlying water column) and greater melt in summer. A change in the direction and speed of ice motion has also played a role, with the ice departing quicker from the Arctic Basin through Fram Strait rather than circulating many times inside the Arctic.

    The summer (September) area of sea ice reached a record low in 2007, almost matched in 2011, but what is most serious is that the thinning continues. It is inevitable that very soon there will be a downward collapse of the summer area because the ice will just melt away. Already in 2007, measurements indicated that during the summer there were 2 metres of melt off the bottom of ice floes in the Beaufort Sea, while the neighbouring first-year floes had only reached 1.8 metres during winter – so all first-year ice was disappearing. This effect will become more important and will spread throughout the Arctic Basin.

    There is currently disagreement about when the summer Arctic will become completely ice-free. It depends on which model is being employed. My own view is based on purely empirical grounds, that is, matching the observations of area from satellites with observations from submarines (combined with some modelling) of thickness to give us ice volume. If we think in volume terms instead of area terms, the downward trend is more than linear, in fact it is exponential, and if extrapolated it gives us an ice-free summer Arctic as early as 2015 or 2016.

    Others have talked of later dates, like 2030-2040, but I do not see how the trend of summer ice volume can possibly permit this. Those who agree include W Maslowski, a leading ice modeller (Naval Postgraduate School, Monterey), and the PIOMAS project at University of Washington which generated the data shown below [4].

    The figure shows the minimum volume of Arctic sea ice in midsummer, based on areas observed from satellites and thickness trends inferred from submarine observations. Extrapolation leads to a zero volume in 2015. It must be pointed out that this perspective stands in direct contradiction to very complacent statements about the Arctic sea ice from the IPCC in the AR4 report of April 2007 saying the sea ice was very likely to last beyond the end of the century.

    The ice retreat is having major impact on the planet. The Arctic is the most rapidly warming region on earth (warming at 3-4 times the rate of low latitudes). It has become widely accepted that Arctic amplification of global warming is due to the albedo effect of sea ice retreat. The increased open water reduces the albedo (fraction of solar radiation reflected into space) and causes warming at high northern latitudes to be much faster than the tropics, with enormous implications for climatic instability. Secondly, the summer retreat of the ice from the wide Arctic continental shelves (particularly the East Siberian Sea) allows the shallow surface layer to warm up, bringing temperatures of up to 5 degrees C right down to the seabed.

    Quantification of this effect has only very recently been attempted, in a paper to the 2011 AGU by Hudson [5]. The startling conclusion is that the rate of warming of the Arctic from the sea ice albedo effect could double or worse, once the Arctic Ocean is ice-free in September. And it could double again, once the ocean is ice-free for half the year. But the timescale makes this all the more worrying.

    The scientific community has drawn attention to the risk of dangerous climate change if the world does not reduce greenhouse gas emissions – a worthy and critical objective. However, I wish to point toward a much more immediate problem that does not seem to be recognised among the climate change community at large: This is the problem of rapid retreat of Arctic sea ice, and likely consequence of catastrophic methane feedback.

    These rapidly warming temperatures are accelerating the melt of offshore permafrost, releasing methane, trapped either as methane hydrates or as free gas beneath the permafrost, and causing large plumes of methane to appear all over the summer Arctic shelves (observed for the last 2-3 summers by Semiletov and colleagues on joint University of Alaska – Far Eastern Research Institute cruises). Methane levels in the Arctic atmosphere have started to rise (measured by Dr Leonid Yurganov, Johns Hopkins University) after being stable for some years. As methane is a very powerful, if short lived, greenhouse gas (as much as 105 times as powerful per as unit weight of CO2 over a 10 year time horizon, though only lasting about 8 to 12 years in the atmosphere), this will give a strong upward kick to global warming.

    According to research crew leader Igor Semiletov, “We carried out checks at about 115 stationary points and discovered methane fields of a fantastic scale – I think on a scale not seen before…. This is the first time we’ve found continuous, powerful and impressive seeping structures more than 1,000 meters in diameter.” [6] He has also described how warmer temperatures are making their way down to the bottom of the shallow sea in the Arctic continental shelf areas: “When ice has gone, there are stronger winds and waves and a deeper mixing of water which causes the comparatively warm upper layer to mix with water at deeper levels. There are already studies which confirm that in some areas, bottom temperature in summer is 2 to 3 degrees above zero Celsius (freezing). As this warming spreads to a larger area, the more that shelf-based permafrost will thaw.” [7] There have been warnings that a major methane outbreak may be imminent.

    In a piece Archer co-authored in 2009 [8], he acknowledged both the significant warming power of methane and the fragile and “intrinsically vulnerable” nature of hydrates: “There are concerns that climate change could trigger significant methane releases from hydrates and thus could lead to strong positive carbon-climate feedbacks. …. Methane hydrate seems intrinsically vulnerable on Earth; nowhere at the Earth’s surface is it stable to melting and release of the methane.” In this same piece, Archer affirms another key factor: “Rapid warming well above the global average makes the Arctic hydrates particularly vulnerable to climate change.”

    Archer clearly acknowledges the vulnerability of methane hydrates to thawing in response to rising Arctic temperatures. Accelerating ice loss can only accelerate that temperature rise through the albedo effect, so we should be regarding the potential loss as an imminent and urgent crisis. Ira Leifer, from the Marine Science Institute at UCSB, describes the mechanics of a “runaway” methane feedback: “A runaway feedback effect would be where methane comes out of the ocean into the atmosphere leading to warming, leading to warmer oceans and more methane coming out, causing an accelerated rate of warming in what one could describe as a runaway train.” [9]

    Given that this “train” would be one way and feed upon itself in a way that might well be unstoppable by humanity, it would seem to be a classic case where the precautionary principle should be invoked as a justification for action.”

    ….

    R.Gates, who recently re-posted this at Neven’s Arctic Sea Ice site, added:

    “With the Met Office still officially saying 2030 for an ice free Arctic, Dr. Wadhams is quite specific in thinking 2015 or 2016. Now, who seems more likely to be correct? And if Dr. Wadhams is more correct on that score, who are you going to believe– those who say methane is not an immediate threat, or Dr. Wadhams who thinks it is very much so.

    Just food for thought.”

    http://neven1.typepad.com/blog/2012/09/signs-of-arctic-climate-change.html

    (For the record, I am not in agreement with the pro-geo-engineering folks that these positions seem to sometimes be connected with. I just want to get as clear a view of what the range and relative danger of the various imminent threats we face may be, and this takes active discussion, and especially input from such authoritative figures as Wadhams.)

    Comment by wili — 9 Sep 2012 @ 12:37 PM

  245. wili, you know what we can do about the methane threat, right?

    Burn less fossil fuel. It’s really as simple as that.

    There’s no alternative that makes sense.

    Wadhams is much in the news lately, and does have some publications that show up in Scholar; here’s one using submarine data to characterize multiyear ice, saying the ice is changing structure compared to how it behaved in the past; interesting:
    http://www.sciencedirect.com/science/article/pii/S1873965212000084

    Comment by Hank Roberts — 9 Sep 2012 @ 2:38 PM

  246. The 2030 date for an ice free Arctic must be an obsolete now. In the light of recent events surely the only way it could happen this late is for a dramatic reversal of the current trend. Is there any such thing in the pipeline?

    Comment by DP — 9 Sep 2012 @ 3:10 PM

  247. DP: The 2030 date for an ice free Arctic must be an obsolete now.

    Sure does seem as though events are outpacing our understanding by a long mile, on the human timescale.

    Thing is, short of constructing a seamless, gap-free and correctly functioning physical model of what’s happening we’re reduced to conjecture of the innocent variety. Our present comprehension appears to be at that level despite the sincere best efforts of our most virtuous workers.

    In the postmortem of history our scientists should get due credit for delivering a reasonable and continuously refined span of time in which the Arctic would stop working as we’re accustomed to it, information way better than a sheer guess.

    Our skills for this project were a little too late to emerge. Bummer, but on the other hand it doesn’t really change anything. Hank’s universal suggestion is still valid: stop making C02.

    Comment by dbostrom — 9 Sep 2012 @ 3:39 PM

  248. Hank, yes, of course, I agree. As Jurgen Randers said quite bluntly recently, we have to stop burning fossil fuels, period.

    I don’t fly, rarely drive or eat meat, rarely cool my house in summer and barely heat it in winter, and I’ve been active at nearly every level–neighborhood, family, work, municipal, state, national…–to change policies toward zero-emissions society.

    I still want to have as clear an idea as possible of what we are facing.

    Yes, I’ve seen that thing about change in nature of ice structure. Very interesting, indeed.

    On another front, do we have a clear idea what the major elements were that the earlier models missed when they were predicting an ice-free Arctic Ocean to not show up till at least 2070? (Apologies if this was covered somewhere and I missed it.)

    (reCaptcha: “and worry yet”!)

    Comment by wili — 9 Sep 2012 @ 4:20 PM

  249. My amateur view on methane release is similar to David Archer’s. Here is my reasoning.

    From
    http://en.wikipedia.org/wiki/File:Five_Myr_Climate_Change.png
    I estimate that methane accumulated in the arctic regions from about 2.6 mya until the first substantial interglacial around 0.4 mya (although some would have been released at the intermediate warming event about 1.1 mya). So whatever could accumulate during a 2.2 million year interval would have been released during that event (interglacial 5?). Then some methane further accumulated until interglacial 4 about 0.325 mya. That is quite a substantial warming, so methane formed even far in the past would be released. What I’m calling interglacial interglacial 3 about 0.24 mya again would release the more shallowly buried of the methane accumulated over the intervening 85,000 years. Once again methane accumulated up to interglacial 2, the Eemian, which was again a strong warming event, evaporating methane buried rather deeply.

    All that is current left is that which has accumulated since the Eemian interglacial, a mere 125,000 years worth; isn’t much there.

    There isn’t much there as far as effects are concerned by looking at the entire history of the Quaternary to notice that the only temperature spikes are the interglacials driven by orbital forcing and it didn’t warm enough to result in massive extinction events, etc.

    However if it warms more now than even during the Eemian (as appears likely, I fear) then deeper methane (if any) will be released. Those who care to might attempt to discover estimates of just how big such a resevoir might be.

    Comment by David B. Benson — 9 Sep 2012 @ 6:21 PM

  250. #246 DP “The 2030 date for an ice free Arctic must be an obsolete now”

    If you look carefully at Hadley’s model yearly minima projections. They were really off by way more than 40 years. So my question ever since 2007 super melt…… Have they found out what was wrong with the Arctic Ocean model? Its not embarrassing at all to find out the reasons of the sea ice minima model failure. In fact by finding out why we come to a better understanding of climate and weather. Does it take 5 years before they can find the flaws? 5 years is a lot of runs or computer time…. Surely they must have made some progress?

    Comment by wayne davidson — 9 Sep 2012 @ 7:15 PM

  251. Benson, my understanding is that there is quite a bit of methane at deeper levels, much of it in free pools of methane awaiting a pathway for escape. But it is true that we don’t have really accurate estimates of how much is down there, as far as I can tell. Although I haven’t heard anyone (reputable) say that if it’s all released it would not be a very significant contributor to overall GW.

    Wayne, I second your question. As I understand it, a central purpose of creating models is exactly to see where they break down so the next set of models can be perfected, and then we see where those break down, ideally in smaller and smaller areas so the models get more and more accurate over time.

    So what have we learned from these failures? What were the major factors that were left out that might have accounted for the rapid deterioration of the sea ice that we have actually seen?

    Hank, I agree, and would only add that, as Jurgen Rander recently put it, we all have to stop burning fossil fuels. I’ve come a long way, down to a small fraction of what my fellow Americans burn. But I still have a ways to go to get to zero. But for some reason, though I know that the response should be the same in any case, I still want to have as accurate picture of where we are as I can no matter how grim the truth turns out to be. I guess I kinda thought that this was one place where one could find out.

    Comment by wili — 9 Sep 2012 @ 7:59 PM

  252. Sorry if this was covered elsewhere, but an interesting feature is the large hole in the Arctic pack, barely a few hundred kilometers away from the pole. It seems that it started out over a month ago, as a small speck on the images, roughly at the time of the Arctic cyclone. Intuitively, one would have thought that in a calmer weather, sea ice would have reformed soon afterward, closing that odd gap. Instead of that, the hole more or less regularly widened, covering tens of thousands of square km, near an -also unusual- dent on the edge of the ice cover. Persisting after so many days, and visible on just about every map (extent, concentration, temperature…), it lends credence to the expectation of an early melt of most of the ocean. Chances are, such an event could take place right at the pole, leaving plenty of room for all the submarines of the world to surface.

    Comment by François — 10 Sep 2012 @ 4:32 AM

  253. François, the hole in the ice isn’t difficult to explain. If you take a look at an ice age chart, you will see that the area is first year ice, and it is all disintegrating.

    It’s still unusual (the ice edge is closer to the pole than I think it has ever been) but the real unusual aspect is this year virtually every last scrap of first year ice will have melted or very nearly melted. If this happens again next year, it’s game over for the Arctic.

    I also expect that next year the transpolar drift will have pushed a big area of multiyear ice directly over the pole, which will decrease the chances that another hole will open up directly over the pole, but increase the chances that all the first year ice will be vulnerable again.

    Comment by Didactylos — 10 Sep 2012 @ 7:01 AM

  254. Didactylos 253, well written, it is highly likely that the Pole will be ice free next year (yet again). It is a matter of an AO being negative during summer like it was in 2007 when the over all ice thickness was greater, a sure thing if so, or a slower gradual melt under cloudier conditions like what is happening now.

    Comment by wayne davidson — 10 Sep 2012 @ 7:21 AM

  255. > my understanding is …
    > methane at deeper levels, much of it in free pools
    > … I guess I kinda thought …
    > this … place where one could find out.

    Want to find out what’s been published in science?
    You can get help with that here. People have tried.
    But nobody can help you “find out” what hasn’t been found yet.

    Comment by Hank Roberts — 10 Sep 2012 @ 7:29 AM

  256. Nice graphic here.

    http://blueandgreentomorrow.com/2012/09/10/arctic-sea-ice-continues-its-worrying-decline/

    Comment by John E. Pearson — 10 Sep 2012 @ 7:58 AM

  257. ps wili, for the ‘pools’ stuff — probably that’s from Huffington Post wackywoo ‘methane tsunami’ stuff. It’s a crap site. Separate the wackywoo stuff from the published science, don’t assume one relates to the other.

    Comment by Hank Roberts — 10 Sep 2012 @ 8:14 AM

  258. > nice graphic
    That’s from http://www.skepticalscience.com/news.php?n=1608

    I see they’re using a curved line through the points. Is that supported?

    Comment by Hank Roberts — 10 Sep 2012 @ 9:32 AM

  259. Superman1, #243, says that if we suddenly ceased all FF use, we would still face temps rising to pre-industrial plus 3C.

    No one has yet bothered to comment, but my best understanding is that he (pronoun chosen based on handle!) is confusing a sudden stop in FF use with holding CO2 steady at current levels, something interesting to model though unlikely to be seen exactly in real life. Furthermore, I believe this is a common confusion.

    I would appreciate a comment confirming my take, or straightening me out if needed, from someone above my pay grade on this site, of whom there are plenty among the regulars.

    Comment by Ric Merritt — 10 Sep 2012 @ 11:52 AM

  260. >I see they’re using a curved line through the points. Is that supported?

    In terms of the observed data a curved line is definitely supported. Gompertz, exponential or quadratic all fit minimum area, extent or volume significantly better than a straight line does. Putting it the other way round, from a statistical standpoint a straight line is *not* supported: it leaves a pattern of residuals that are systematically negative in the early years, positive in middle years, and increasingly negative again at the end. Like a textbook illustration of when the linear model is wrong.

    Comment by L Hamilton — 10 Sep 2012 @ 12:16 PM

  261. #259–”I see they’re using a curved line through the points. Is that supported?”

    IIRC, it’s a better statistical fit than linear. But I don’t have details, and am just ‘driving by’ at the moment, so can’t check right now.

    Comment by Kevin McKinney — 10 Sep 2012 @ 12:25 PM

  262. Hi hank. I do remember reading that Huff Post article.

    But I think it was this Shakhova quote that first put it in my mind. It’s not a published, peer-reviewed statement, but it is from an expert in the field (unless you care to just label anything you don’t agree with as “wackywoo”).

    “subsea permafrost acts as a lid – the seal to prevent this methane escape. And being prevented for a period of time, being sealed for a period of time, means that this gas accumulates, and it accumulates under higher pressure – this is what we have to give an example, this is what we have, for example, this bottle of champagne. So, you have a lot of gas inside, but it’s sealed for a period of time, and when you uncork this bottle, what you can see – it’s different from a bottle of mineral water left open for period of time, it’s just little bit of different. And I think that release of methane from this kind of seabed deposits disturbed by destabilization of subsea permafrost, provides a pathway for this methane – ready to go methane – because its release does not depend on production. It’s not time-dependent, it’s not temperature-dependent, it only needs the pathway to be released.”

    It’s from a _Science_ podcast. IIRC, that is a fairly reputable journal. But perhaps I’m mistaken.

    http://www.sciencemag.org/content/327/5970/1265.2.full

    Comment by wili — 10 Sep 2012 @ 2:38 PM

  263. Ric,

    Your understanding is correct. If mankind was to disappear tomorrow, CO2 levels would immediately drop and cooling would commence. The built-in warming is for constant emissions. Here is a cool java applet:

    http://carboncycle.aos.wisc.edu/index.php?page=carbon-budget-tool

    Comment by t_p_hamilton — 10 Sep 2012 @ 3:18 PM

  264. Ric Merritt @259
    Would this RealClimate post of 2010 suit your purpose as an explanation of the the difference between fixing today’s radiative imbalance and a complete cut-off of CO2 & other GHGs?

    Superman1 @243 did however add more agents of extra warming to his account that just today’s radiative imbalance as he points to the warming that would come from negative forcings falling to zero. The uncertainties surrounding such forcings are large but they could very well equal (& could even exceed) the present net forcings, as Superman1 implies from his calculations.

    Comment by MARodger — 10 Sep 2012 @ 3:57 PM

  265. Hi Ric,

    Ending fossil fuel emissions leads to a reduced concentration of carbon dioxide in the atmosphere. A parametrization of what happens can be found in Kharecha, P.A., and J.E. Hansen, 2008; Global Biogeochem. Cycles, 22, GB3012

    Warming would cease fairly quickly as the concentration rapidly drops. Eventually, we’d end up at about 9% above pre-industrial if we ended emissions today. For a sensitivity of 3 C per doubling of carbon dioxide, we’d end up with about 0.3 C of warming above pre-industrial, less than the 0.8 experienced so far. Thus, cooling would be the result of ending emissions, though not completely back to the pre-industrial climate.

    Stabilizing the concentration of carbon dioxide at the present level does imply additional warming. Stabilization also required additional emissions if the final stabilization level is greater than 300 ppm or so. For stabilization at 450 ppm, we’d need about half of year 2000 emissions from about 2030 to the end of this century and then reducing down to about a quarter of that over the following two centuries. Here’s a bit of IDL code to look at that situation:

    ; To run this script in the absence of an IDL license, the Fawlty Language can
    ; be used for free. In either case, save this as a file and type '@filename'
    ; at the prompt. You could also cut and past this to the prompt in IDL.
    ;
    ; Reference: Kharecha, P.A., and J.E. Hansen, 2008
    ; Global Biogeochem. Cycles, 22, GB3012
    ;
    a=findgen(1000) ;year since 1850
    b=fltarr(1000) ;BAU concentration profile
    b(0)=1
    for i=1,999 do b(i)=b(i-1)*1.02 ;2 percent growth
    ;plot,b(0:150)*4.36+285.,/ynoz ; 370 ppm year 2000
    c=(18.+14.*exp(-a/420.)+18.*exp(-a/70.)+24.*exp(-a/21.)+26.*exp(-a/3.4))/100. ;Kharecha and Hansen eqn 1
    e=fltarr(1000) ;annual emissions
    for i=1,999 do e(i)=b(i)-b(i-1)
    d=fltarr(1000) ; calculated concentration
    t=450.-285. ;target concentration
    f=0 ;flag to end BAU growth
    for i=1,499 do begin & d(i:999)=d(i:999)+e(i)*c(0:999-i)*4.36*2. & if d(i) gt t then begin & e(i+1:999)=e(i)/1.5 & f=1 & endif else if f eq 1 then e(i+1:999)=(t-d(i+1))/4.36/2. & endfor ;factor of two reproduces BAU growth
    !p.multi=[0,2,2]
    plot,a+1850.,d+285.,/ynoz,xtit='Year',ytit='carbon dioxide concentration (ppm)',charsize=1.5 ; atmospheric carbon dioxide concentration in ppm showing target achieved
    plot,a(0:499)+1850,e(0:499),xtit='year',ytit='carbon dioxide emissions (AU)',charsize=1.5 ;emission profile to reach target in arbitrary units
    oplot,a(0:499)+1850,fltarr(500)+e(150)/2.,linesty=2 ;half of year 2000 emission level

    Comment by Chris Dudley — 10 Sep 2012 @ 4:22 PM

  266. I notice at http://arctic.atmos.uiuc.edu/CT/animate.arctic.color.0.html that there is an area of sea ice just to the north of Fordovoye Island about the size of Iceland (100,000km2) which is becoming seperated and could melt within 4-5 days at current rate.

    I do think it will go and will be a significant contribution at the time it would normally be flattening out.

    Anyone else seen this ?

    Comment by cumfy — 11 Sep 2012 @ 5:42 AM

  267. Re my #259, thanks for the answers and links. Modeling scenarios has its uses, but we shouldn’t exaggerate the real-world applicability of ones like immediate cessation of FF use, something that will happen only if most or all of us drop dead. It tends to draw attention away from the very real, indeed crucial differences between BAU and bending the curve downward with increasing urgency.

    Comment by Ric Merritt — 11 Sep 2012 @ 11:46 AM

  268. Here’s my updated PIOMAS Arctic Sea Ice Volume animated graph from 1979 to 2012-09-02.
    A chilling illustration.

    Comment by Andy Lee Robinson — 11 Sep 2012 @ 12:52 PM

  269. Ric (#267),

    James Hansen has pointed out that the atmospheric carbon dioxide concentration is going to be a climate control tool from now on. We’ll be holding it within a certain range to suit our climate preferences.

    He has proposed 350 ppm as a suitable target. It is worth knowing then that holding at 350 ppm will require some further emissions. The popular 450 ppm target actually requires substantial emissions to attain and maintain for some time to come. Making cuts now is definitely needed because, as you say, the instantaneous substantial cut won’t work, but it is worth considering this effort as our most convenient form of geo-engineering.

    This is why the Kyoto style methods will ultimately be successful. Just as everyone has an interest in currency stability, so all will have an interest in climate stability and will undertake concerted efforts to achieve it.

    Comment by Chris Dudley — 11 Sep 2012 @ 4:42 PM

  270. 269 Chris said, ” so all will have an interest in climate stability and will undertake concerted efforts to achieve it.”

    Not even close to real. Folks with fossil fuel resources have a $5-10 cost product and consumers have perhaps a $150/barrel equivalent price to pay for alternatives. Are you saying that a .000000001% increase in CO2 concentrations will deter someone facing a 1500% profit?

    Naw, the truth is that “we” want to increase our production of CO2-generating fossil fuels while limiting “others’” production. It is pure-t-insanity to reduce fossil fuel production for any single producer, and since the lowest price where that ceases to be true is perhaps $25 a barrel, can you name ANY fossil fuel producer who will benefit from their individual choice to not drill, baby, drill?

    It ain’t consumption that matters, it’s production. Coal is the best example. The USA is reducing coal consumption. How much has that affected coal production? Not much, as the surplus is just exported. There’s always a market somewhere for expensive energy when nearly all the costs are externalized.

    Comment by Jim Larsen — 11 Sep 2012 @ 10:44 PM

  271. And, the more you threaten fossil fuels, the more imperative it becomes to produce them as fast as possible to get those sales in under the wire. All this AGW stuff just increases producers’ desire to sell as much as possible as soon as possible. Fossil fuels is a ~80% profit business. As if carbon taxes or anything else will change facts. Fossil fuels are useless to their owners when left in the ground, and wildly profitable at any price or tax rate when drilled. Ergo, they WILL be drilled.

    Durn, making a billion dollars will increase temps 0.01 degrees, resulting in a $10 a month increased utility bill for me. Oh well, I SUPPOSE I can live with that, assuming I can complain about Soc-ialist Government interference in the Perfect Marketplace….

    Now, those OTHER folks who don’t resemble me, well, they should stop producing fossil fuels immediately!

    Comment by Jim Larsen — 11 Sep 2012 @ 11:21 PM

  272. After a three day hiatus in record setting, a new record low arctic sea ice extent has been set, the sixteenth this year. http://www.ijis.iarc.uaf.edu/en/home/seaice_extent.htm

    Comment by Chris Dudley — 12 Sep 2012 @ 5:30 AM

  273. Jim (#271),

    I wonder how strong your “under the wire” argument is. Suppose, for example, that CAFE standards have limited consumption to the point that people would have to drive 48 hours a day to be able to match the oil production capacity available. At that point, where is the profit in producing more oil? It will just drive the price down below the cost of production. Oil is as profitable as it is because a cartel limits production. And, they have certainly reduced their market share in the electricity supply market by acting as a cartel. They are even losing market share in transportation.

    As there is a coal export cartel developing as well, we may see similar practices with regard to coal too.

    Comment by Chris Dudley — 12 Sep 2012 @ 6:12 AM

  274. For Jim and Chris, FF producers will always find a way to squeeze more profit out of dumping the costs on the commons. Shale oil is the latest “cartel”. The arctic is the next ‘commons’ [to get back on topic].

    Comment by flxible — 12 Sep 2012 @ 8:22 AM

  275. I am partially responsible for the OT discussion, sorry. I wanted to clarify Superman1′s OT remarks, but should have referred to them from the Unforced Variations thread.

    I think we’re into diminishing returns, so I’ll stop here, barring anything really new and important.

    Comment by Ric Merritt — 12 Sep 2012 @ 11:35 AM

  276. I like that chart Dudley (post 272). By showing averages for the decades, 80′s, 90′s & 2000′s it’s easy to see the gap between each period is increasing. Now, if we take 2011 & 2012 as part of a new decades average, it’s easy to see this decade will again show a much bigger gap from previous decades. The gap increases will at some point cease, but only because the summertime ice extent minimums hit zero.

    On a different note, someone had a bar chart comparing melt for Greenland, with a much bigger bar shown for 2012. I lost the link – anyone have that?

    Comment by Perk Earl — 12 Sep 2012 @ 12:15 PM

  277. Two points on consequences of the melt:

    http://www.nature.com/news/ice-loss-shifts-arctic-cycles-1.11387

    “The cold surface layer — called the halocline — isolates the sea ice from the warmer water below.

    But the halocline is vulnerable to warming from above, says Henning Bauch, a marine geologist at the GEOMAR research centre in Kiel, Germany. A thinning halocline — something that has not yet been observed — would not only jeopardize the sea ice but could also melt the carbon-rich permafrost beneath shallow coastal waters, releasing greenhouse gases into the atmosphere.”

    And for a great (sad) video on the local and immediate consequences to Arctic life:

    http://www.youtube.com/watch?v=cE7TCvgLqo4&feature=plcp

    (Thanks to dorlomin at neven’s blog for this link.)

    Comment by wili — 13 Sep 2012 @ 8:29 AM

  278. Perk (#276),

    I like those plots too. And the group that produces them is quite responsive as well. Yesterday looks like the 17th record low sea ice extent this year.

    Comment by Chris Dudley — 13 Sep 2012 @ 12:05 PM

  279. Another perspective on the failure of the IPCC modelers to anticipate the pace of sea ice loss in the Arctic:

    http://www.aglmedia.co.uk/index.php/wasdell-ipcc

    Comment by wili — 14 Sep 2012 @ 6:28 AM

  280. > failure of the IPCC modelers

    The IPCC does not have any modelers.

    The IPCC didn’t “fail” — they explained the lack of information.

    Last time, very little had been published on the subject.
    So little was available that they could not say anything!

    Don’t feed the deniers, who like to make absence of evidence into evidence of conspiracy or failure.

    I think your heart is in the right place, but accusations of failure need to be guided by the head — simply demanding that something should exist isn’t enough to make it happen, especially retroactively.

    Comment by Hank Roberts — 14 Sep 2012 @ 11:11 AM

  281. An 18th record low see ice extent set in 2012 yesterday.

    Comment by Chris Dudley — 14 Sep 2012 @ 11:34 AM

  282. Ric Merritt #259,

    You make the following comment:
    “Superman1, #243, says that if we suddenly ceased all FF use, we would still face temps rising to pre-industrial plus 3C.
    No one has yet bothered to comment, but my best understanding is that he (pronoun chosen based on handle!) is confusing a sudden stop in FF use with holding CO2 steady at current levels, something interesting to model though unlikely to be seen exactly in real life. Furthermore, I believe this is a common confusion.
    I would appreciate a comment confirming my take, or straightening me out if needed, from someone above my pay grade on this site, of whom there are plenty among the regulars.”

    MRodger #264 responded to your comment as follows:
    “Superman1 @243 did however add more agents of extra warming to his account that just today’s radiative imbalance as he points to the warming that would come from negative forcings falling to zero. The uncertainties surrounding such forcings are large but they could very well equal (& could even exceed) the present net forcings, as Superman1 implies from his calculations.”

    You then commented (#267):
    “Re my #259, thanks for the answers and links. Modeling scenarios has its uses, but we shouldn’t exaggerate the real-world applicability of ones like immediate cessation of FF use, something that will happen only if most or all of us drop dead. It tends to draw attention away from the very real, indeed crucial differences between BAU and bending the curve downward with increasing urgency.”

    I will address the comments above. I chose the extreme case of ending fossil fuel combustion immediately to identify the consequences of what we have done already. If we have done the analog of giving ourselves Stage 4 cancer, then we know that ANY continuation of fossil fuel combustion will accelerate a terminal situation.

    Now, in the last few days, I’ve been reading some papers on ‘climate commitment’, ‘aerosol forcing’, and ‘climate sensitivity’. There is not consensus overall among the experts, but here’s what I’ve gathered. We have generated a temperature increase of about 0.8 C above pre-industrial from the fossil fuels we have burned so far. On that issue, there is pretty much consensus. The CO2 we have placed in the atmosphere will remain there a long time even if we were to terminate fossil fuel combustion today, decreasing slowly. We can expect an additional temperature increase from this resident CO2 over the next few decades of about 0.7 C, due to the ‘climate commitment’. Some experts place the additional temperature increase at 0.6 C, but 0.6-0.7 C is the ballpark.

    But, the large uncertainty is the cooling effect if we were to terminate fossil fuel use today. Burning fossil fuels is accompanied by sulphate aerosols that go into the atmosphere, and result in increased albedo. They essentially mask much of the CO2 heat-trapping effect through this increased albedo cooling. The aerosols, unlike CO2, have a relatively short residence time in the atmosphere, on the order of days to weeks. As they leave, there is an extra heating effect. A while back, Hansen estimated this effect to be about the same as the two CO2 temperature increases listed above. These three effects would total about 3 C. Some of the more recent papers show smaller numbers for the aerosol heating , ranging from 0.5 C to 1.0 C, with the possibility that the number could be larger. The problem is the difficulty of separating climate sensitivity from aerosol forcing. My present estimate based on these more recent papers would be about 2.5-3.0 C if we were to terminate fossil fuel combustion today. A temperature increase of 2.5 C does not change my argument or conclusions based on 3 C. I see no evidence that temperature increases of this magnitude can be stabilized, given all the positive feedbacks we are seeing today with an increase of only 0.8 C.

    Obviously, we won’t stop using fossil fuels today, and my guess of the most probable scenario is that we will continue to increase fossil fuel use and CO2 emissions ad infinitum. I see no evidence of any decrease in fossil fuel use or production; all evidence I see is for unlimited production.

    I hope this clarifies my position.

    Comment by Superman1 — 14 Sep 2012 @ 12:16 PM

  283. Hank @280–yes, I should have put “failure” in scare quotes. If you viewed the very short video, he makes pretty much your points.

    Comment by wili — 14 Sep 2012 @ 5:44 PM

  284. CT SIA keeps dropping: now 2.234 million square kilometers.

    Have these ice thickness images (right hand column) been linked here before? I find them fascinating/sickening:

    https://sites.google.com/site/apocalypse4realseaice2012/home/sea-ice-concentration-and-thickness-comparison

    Comment by wili — 15 Sep 2012 @ 11:39 AM

  285. A longish post of mine just got flagged as spam. It just said that, looking at the images on the right hand side of that site, plus what we know about the quality and thickness of the of sea ice, makes me realize that, really, the polar ice cap is already gone. Saying it’s still an ice sheet is like cutting down a forest, but then saying it’s still a forest since you left a couple trees and some bushes and vines still cover parts of the old forest floor.

    Comment by wili — 15 Sep 2012 @ 1:53 PM

  286. I saw that I wrote see instead of sea yesterday. What a teeter-totter. A nineteenth record has occurred.

    Comment by Chris Dudley — 15 Sep 2012 @ 3:01 PM

  287. While searching for a quantification of ice-albedo, I found this on the NASA site: http://conservationatwork.wordpress.com/2010/07/20/wed-2007-melting-ice-a-hot-topic/
    CERES found an albedo decrease of 0.0027, which equals 0.9 watt of energy per square meter retained in the Earth system over a 4 year period 2000-2004. If this trend is typical it would be equivalent to a doubling of CO2 over 15 years. Clearly there is more research needed, but I could not find any follow up on the NASA site. Maybe this is old hat, or was some kind of artefact, but can anyone here cast any light on this please?

    Comment by Richard Lawson — 15 Sep 2012 @ 5:20 PM

  288. From post 263: “Your understanding is correct. If mankind was to disappear tomorrow, CO2 levels would immediately drop and cooling would commence.”

    Hmm, what about thermal inertia? I thought there was a 30-40 year gap between added CO2 and it’s impact on the oceans, which drive the weather.

    But even beyond that consideration, under what circumstances do you forsee an immediate disappearance of humankind? Aside from a catastrophe that would probably wipe out all other life as well, people will continue to burn FF. Economically there isn’t any choice. In fact, even if we knew unequivacially tomorrow that we are toast if we burn FF for one more year, we would still burn it for years thereafter because the alternative is starvation.

    Comment by Perk Earl — 15 Sep 2012 @ 11:35 PM

  289. Perk Earl #287,

    “Hmm, what about thermal inertia? I thought there was a 30-40 year gap between added CO2 and it’s impact on the oceans, which drive the weather.”

    You are correct. The thermal inertia will result in an increase of about 0.7 C above the present delta T from pre-industrial of about 0.8 C, for a total temperature increase above pre-industrial of 1.5 C. In addition, there is a third effect from the elimination of the fossil sulphates that result from fossil fuel combustion. These sulphates increase the albedo of the atmosphere, and when fossil fuel combustion stops, the sulphates would exit the atmosphere quite rapidly (unlike the CO2, which remains for a long time). This additional temperature increase from removal of the sulphates is more uncertain than the previous two above, but has been estimated to range from 0.5 C to 1.5 C, giving a total temperature increase from these three components of from 2.0 C to 3.0 C. Given the feedbacks we are starting to see already from our present 0.8 C increase, it is difficult to believe that the ~2.5 C temperature increase could be stabilized, and not lead to a temperature runaway.

    Comment by Superman1 — 16 Sep 2012 @ 6:16 AM

  290. A twentieth record has occurred.

    Comment by Chris Dudley — 16 Sep 2012 @ 6:43 AM

  291. Perk Earl @287 & Superman1 @288,
    Can I refer you to this RealClimate post of 2010 in which future atmospheric CO2 & future temperatures are considered for a ‘sudden zero emissions’ future.

    Comment by MARodger — 16 Sep 2012 @ 9:18 AM

  292. MARodger #290,

    “Can I refer you to this RealClimate post of 2010 in which future atmospheric CO2 & future temperatures are considered for a ‘sudden zero emissions’ future.”

    I read it, and remain unconvinced. More convincing is the argument by Ramanathan and Feng, in PNAS. Their opening sentences are: “The observed increase in the concentration of greenhouse gases (GHGs) since the preindustrial era has most likely committed the world to a warming of 2.4 degrees C (1.4 degrees C to 4.3 degrees C) above the preindustrial surface temperatures. The committed warming is inferred from the most recent Intergovernmental Panel on Climate Change (IPCC) estimates of the greenhouse forcing and climate sensitivity.”

    The Ramanathan paper has been cited 70 times, while the Matthews letter has been cited nine times, two of which are self-cites. The CO2 decays very slowly from the atmosphere and, coupled with the ocean warming, produces the ‘pipeline’ effect I have outlined earlier. Add to that the removal of the increased albedo by the rapid elimination of the fossil sulphate aerosols after CO2 emissions have stopped, and you get a total temperature increase of about 2.5 C. That’s what we have committed to already, and I maintain that such a temperature increase cannot be stabilized, and will produce a new equilibrium at some higher temperature.

    Comment by Superman1 — 16 Sep 2012 @ 10:47 AM

  293. Superman 1, post 288: I had read about thermal inertia but did not know the many specifics your post helped to clarify – thanks. I agree, “Given the feedbacks we are starting to see already from our present 0.8 C increase, it is difficult to believe that the ~2.5 C temperature increase could be stabilized, and not lead to a temperature runaway.”

    Comment by Perk Earl — 16 Sep 2012 @ 11:42 AM

  294. > a temperature runaway.

    You need to clarify that or people will mistake it for the “we’re all going to Venus” notion, which assumes burning all the carbon.

    Comment by Hank Roberts — 16 Sep 2012 @ 2:20 PM

  295. Add to that ~2.5C the ~.5C from permafrost (at least). I suspect it doesn’t stop there.

    Comment by Steve Bloom — 16 Sep 2012 @ 3:14 PM

  296. Hank Roberts #293,

    “a temperature runaway.

    You need to clarify that or people will mistake it for the “we’re all going to Venus” notion, which assumes burning all the carbon.”

    I can’t be much more specific. Where the temperature equilibrates depends on the actual reserves of methane that could be released, the rate of release, the number of other substances (such as water vapor) that could be released and contribute to further warming, and the number of other positive feedbacks and how they interact synergistically. I read Maslowski’s recent review of the myriad climate models, and none of these begin to approach incorporation of the above potential contributors to temperature runaway. The increases in Arctic methane that have been reported the last few years based on temperature increases of less than a degree do not bode well, and some other already identified feedbacks further compound the problem. I wish I could be more specific, but I really have no evidentiary basis for that. Intuitively, I believe there will be no decrease in fossil fuel use, and even the unsustainable case described above of ~2.5 C increase is purely wishful thinking. I suspect far more than 2.5 C will be the reality.

    Comment by Superman1 — 16 Sep 2012 @ 3:37 PM

  297. Superman 1 @291.
    The Ramanathan & Feng paper you cite was probably not cited by others for the purpose you propose. This is because the reference you make is not to their finding. As the final sentence of your quote (the opening lines of the abstract) makes plain, the finding you reference is simply inferred from IPCC AR4. Also this finding applies to a scenario where all GHG remain constant, as the continuing quote from their abstract shows.
    The estimated warming of 2.4°C is the equilibrium warming above preindustrial temperatures that the world will observe even if GHG concentrations are held fixed at their 2005 concentration levels but without any other anthropogenic forcing such as the cooling effect of aerosols.

    The final part of this quote about aerosols becomes clear within the paper where they explain they are using 2005 total positive forcing and zeroed negative forcings. The substance of the paper is then a discussion (after a fashion) of factors impacting on that 2.4°C warming. The paper makes a point of saying it does not answer the question “What happens if CO2 emissions cease?” which is what the ‘disappearing mankind’ question asks. The paper however does allow such a question to be answered somewhat better than the abstract alone. But that would require a certain amount of analysis.

    Comment by MARodger — 16 Sep 2012 @ 3:39 PM

  298. Hank, I don’t like multi decadal projections unless they project correctly near term yearly events. It can be argued that the distant future can be very chaotic, also admitting only one major outcome will demand waiting 50 years or so to confirm. Unless the time machines, the models, are accurate. GCM’s are pretty good but they fail to project Arctic ocean sea ice imminent summer demise. It would be of great service for those sitting on the fence, the “it is too long from now to act crowd” if there would be a model projecting current sea ice melts correctly. And also capable of projecting next years melt accurately as well. I am a bit perplexed that the models can’t handle sea ice as correctly as GT trends. The unconvinced waits for tangible proof, and time has not been long enough especially since 2007 . Since the stunning melt of 2007 no other sea ice models have been projecting possible outcomes. I suppose a good model will come out sooner than the next mega event??

    Comment by wayne davidson — 16 Sep 2012 @ 4:09 PM

  299. Why would co2 levels drop if emissions stopped? Why does nature seek to reduce concentrations above pre-industrial levels?

    Comment by DP — 16 Sep 2012 @ 4:22 PM

  300. Hello,

    I wonder if I may ask a question, in respect of the following BBC News item, which made me wonder….

    http://www.bbc.co.uk/news/technology-19576266

    1) Ice breakers weaken the ice in winter, when one might expect it to have a chance to re-form  the volume and thickness it might otherwise achieve, if left intact.

    2) Higher mean temperatures cause melt at the margin of EACH piece of ice created by this mechanical fragmentation, multiplying the melt effect by a fractal effect on this hugely greater surface area and volume, with deeper penetration.

    3) The resulting, cracked surface has a lower albedo and so absorbs more radiative energy than a pristine, intact ice cap with its high reflective index.  This may be smaller, but over a wide area, significant temperature difference increase.

    I wonder why this factor is never discussed, and yet Russia is now planning a nuclear ice-breaker, precursor to more forays into the pack ice.   I have been scanning the scientific press and see no reference to this mechanical effect, which may have contributed to accelerating the  extent and depth of melt rates, by increasing the surface area exposed to thermal effects of solar radiation.

    It should be easy enough to establish the impacts of fragmentation, experimentally, and even assign a value to the degree of fragmentation.  

    At a time when we are seeing unprecedented melting of Arctic sea ice…

    SHOULD THE USE OF ICE BREAKERS IN THE ARCTIC NOT BE FORBIDDEN BY AN INTERNATIONAL TREATY?

    Just a thought….

    Best Regards.

    Toni M
    Bristol, UK

    Comment by Toni — 16 Sep 2012 @ 5:23 PM

  301. MARodger @290 — Thank you.

    DP @298 — Ocean continue to absorb CO2 until equilibrium is reached. That will be well above pre-industrial levels.

    Comment by David B. Benson — 16 Sep 2012 @ 5:44 PM

  302. DP @298.
    You presumably know that about 57% of the CO2 we emit into the atmosphere is effectively absorbed by the biosphere & oceans. This occurs under a regime of on-going & rising CO2 emissions.
    This does not mean the system is in equilibrium at the end of each year. In my understanding, the oceans are the one major player in this not being in equilibrium. If CO2 emissions ceased, the oceans would continue to suck CO2 out of the air for centuries. However the process gets smaller year-on-year as CO2 accumulates in the oceans (and also with any rise in ocean temperature which at depth can lag behind surface temperature rises). As a result the process pretty much slows to a halt after a couple of centuries with about 20% of the CO2 left in the atmosphere. It is eventually removed from the oceans (& thus the atmosphere) by calcium made available from the weathering of rocks, a process that would take thousands (some say hundreds of thousands) of years.

    Comment by MARodger — 16 Sep 2012 @ 6:26 PM

  303. 298 DP asks, “Why would co2 levels drop if emissions stopped? Why does nature seek to reduce concentrations above pre-industrial levels?”

    Rough numbers with errors and omissions, meant to give a visual, not a robust answer:

    Atmospheric carbon VS total atmospheric, bio, & ocean carbon is 1/10, so if you spike atmospheric carbon, the eventual result is 1/10th the initial spike as carbon leaves the atmosphere and flows into the ocean and biosphere. (390ppm – 280ppm) / 10 = 11ppm, so the planet would tend to settle back to ~291ppm if we disappeared and no further feedback occurred.

    Currently 1/2 of human emissions are absorbed, so the rate of decline would be roughly the same as the current increase, at least at first. It took us 130 years to get here, so by 2150 we’d be somewhere around 300 or 325ppm. Not a permanent solution, but this implies that cutting emissions in half would stabilize current concentrations.

    299 Toni,

    The area affected by an icebreaker is teensy compared to the whole ocean, but…

    Another way to look at it is an icebreaker stacks ice in piles while leaving open water. Just like snow plows increase the longevity of snow, icebreakers should increase ice. Plus, in winter open water is grand for ice formation. Combine the two and shouldn’t we take non-fossil icebreakers and plow the Arctic Ocean all winter?

    On a similar level of possibility, we could put a net across the Fram Straight…

    Comment by Jim Larsen — 16 Sep 2012 @ 7:10 PM

  304. Lots of things should be forbidden by international treaty. But the issue of icebreakers will soon be moot.

    Comment by wili — 16 Sep 2012 @ 8:48 PM

  305. Toni M @299 — I am sure the effect is small in comparison the the additional warmth.

    Comment by David B. Benson — 16 Sep 2012 @ 9:02 PM

  306. I have been scanning the scientific press and see no reference to this mechanical effect, which may have contributed to accelerating the extent and depth of melt rates, by increasing the surface area exposed to thermal effects of solar radiation.

    Maybe because there isn’t a lot of “solar radiation” in the Arctic in the winter? Nor is there [yet] much melting going on in winter, especially in the Russian Arctic. Nor is there even much icebreaker traffic there in winter, the icebreakers primarily facilitate tourist and cargo shipping passage during the summer season.
    Russia has had a fleet of N-powered icebreakers for a while now, adding another larger one isn’t likely to accelerate the Arctic melt, and they probably wouldn’t take kindly to the suggestion that use of their Northern Sea Route be outlawed.

    Comment by flxible — 16 Sep 2012 @ 10:24 PM

  307. #299–Toni, please try to do some math first. Even at the current record low minimum, the ice extent is about 3.5 million square kilometers. That’s roughly twice the size of Alaska. In that area, there’s less than a dozen ships.

    If you imagine a dozen snowmobiles driving around two Alaskas for a couple of months, how much do you think they will mark the snow? How often will they meet one another, or cross one another’s tracks? What percentage of the surface will they leave unvisited?

    Hard to say? Well, let’s make some assumptions and run some numbers. Let’s say they travel 200 kilometers a day, and let’s say for simplicity that territory within 1/2 a kilometer of their track is ‘covered,’ so each machine leave a 1-km wide track of ‘covered’ snow behind it. Then:

    12 snowmobiles x 60 days x 200 km = 144,000 square kilometers, less than a 20th of the total. (And icebreakers don’t make 200 km a day through solid ice, and don’t break kilometer-wide swathes.)

    Comment by Kevin McKinney — 16 Sep 2012 @ 10:59 PM

  308. Neven has a new post on models: http://neven1.typepad.com/blog/2012/09/models-are-improving-but-can-they-catch-up.html#more

    Comment by wili — 17 Sep 2012 @ 5:42 AM

  309. Perk (288),

    That lag can be used to set a limit on how high temperatures can rise. In my 265, I realize I forget to integrate eqn. 1 of Kharecha and Hansen when writing my comments, so, killing emissions today leads to about 0.65 C of final warming of the pre-industrial climate, not 0.3 C. But, that is still lower that the 0.8 C we have experienced, so cooling must be the final result of ending emissions now. The eqn was integrated in the code to calculate the concentration.

    How is the lag useful? We can say that we are about 30 years behind where we should be in warming with a 3 C per doubling fast feedback climate sensitivity. And, because the system is driven, that is a lower limit on the lag time for a straight step function response. It is not just the concentration from 1982 that has got us to the warming we expect for 1982 today. We have a higher concentration which drives warming faster, so the observed lag must be shortened from its physical value. Since 30 years is a lower limit on the lag, all we need to ask is at what point in the instantaneous temperature curve does the lagging curve cross the instantaneous curve and have to turn over too cooling. If each year the temperature moves one thirtieth of the way between the lagged curve and the instantaneous curve the maximum temperature is 1.1 C above the pre-industrial climate. So, while at 400 ppm, we’d expect 1.5 C of warming, we can’t get there if we end emissions now, we can’t get above 1.1 C or some lower value before having to start cooling. For a longer lag of 60 years, we stop at 1.0 C and 120 years, 0.96 C. The dashed, dot-dashed and triple-dot-dashed lines in the first panel produced here show this. Longer lags give lower maximum temperatures.


    a=findgen(1000) ;year since 1850
    b=fltarr(1000) ;BAU concentration profile
    b(0)=1
    for i=1,999 do b(i)=b(i-1)*1.02 ;2 percent growth
    ;plot,b(0:150)*4.36+285.,/ynoz ; 370 ppm year 2000
    c=(18.+14.*exp(-a/420.)+18.*exp(-a/70.)+24.*exp(-a/21.)+26.*exp(-a/3.4))/100. ;Kharecha and Hansen eqn 1
    e=fltarr(1000) ;annual emissions
    for i=1,999 do e(i)=b(i)-b(i-1)
    d=fltarr(1000) ; calculated concentration
    t=400.-285. ;target concentration
    f=0 ;flag to end BAU growth
    for i=1,499 do begin & d(i:999)=d(i:999)+e(i)*c(0:999-i)*4.36*2. & if d(i) gt t then begin & e(i+1:999)=0 & f=1 & h=i & endif else if f eq 1 then e(i+1:999)=0 & endfor ;factor of two reproduces BAU growth
    !p.multi=[0,2,2]
    g=alog(d/285.+1)/alog(2.)*3; instantaneous temperature curve.
    gg=g*0.8/1.5
    for i=h, 998 do gg(i+1)=gg(i)+(g(i)-gg(i))/30. ; 30 year lag curve
    gg6=g*0.8/1.5
    for i=h, 998 do gg6(i+1)=gg6(i)+(g(i)-gg6(i))/60. ; 60 year lag curve
    gg12=g*0.8/1.5
    for i=h, 998 do gg12(i+1)=gg12(i)+(g(i)-gg12(i))/120. ; 120 year lag curve
    plot,a+1850.,alog(d/285.+1)/alog(2.)*3.,/ynoz,xtit='Year',ytit='Final warming (C)',charsize=1.5 ; Temperature assumming 3 C per doubling of carbon dioxide concentration
    oplot,a+1850.,gg,linesty=2
    oplot,a+1850.,gg6,linesty=3
    oplot,a+1850.,gg12,linesty=4
    plot,a(0:499)+1850,e(0:499),xtit='year',ytit='carbon dioxide emissions (AU)',charsize=1.5 ;emission profile in arbitrary units

    Comment by Chris Dudley — 17 Sep 2012 @ 12:34 PM

  310. CD #309: Interesting clarification, however it still begs the question of how would FF emissions stop? Maybe enough renewables, Ecat cold fusion or hot fusion, or economic collapse. Something else to consider is once we stop spewing aerosols in such enormous tonnage, we lose global dimming and there’s more warming too.

    In any case, popped on here tonight to post this: Talking about the state of the climate, let’s get a geographic understanding of how much 2012′s ice extent is less than 2007′s record.

    Here’s a graph at NSIDC:
    http://nsidc.org/data/seaice_index/images/daily_images/N_stddev_timeseri

    Looking at the numbers at left, it appears the melt right now is at about 3370k kilometers. 2007′s record was 4170k, for a difference of ~800,000 sq. kilometers.

    Here’s a link showing the size of different US states in miles and kilometers: http://www.enchantedlearning.com/usa/states/area.shtml

    The reduced ice extent for 2012 has so far exceeded the 2007 record by an area approx. equal to Texas (695k) and Kentucky (104k)!

    Comment by Perk Earl — 17 Sep 2012 @ 11:38 PM

  311. Chris Dudley #309,

    The paper by Friedlingstein and Solomon, PNAS, 2005, lays it out in this excerpt from their Abstract:

    “We estimate that the last and the current
    generation contributed approximately two thirds of the present day CO2-induced warming. Because of the long time scale required for removal of CO2 from the atmosphere as well as the time delays characteristic of physical responses of the climate system, global
    mean temperatures are expected to increase by several tenths of a degree for at least the next 20 years even if CO2 emissions were immediately cut to zero; that is, there is a commitment to additional CO2-induced warming even in the absence of emissions.”

    Comment by Superman1 — 18 Sep 2012 @ 6:01 AM

  312. A 21st record low arctic sea ice extent was set on the 16th of September. The 17th saw a rise in extent. Presently, the recovery rate needed to get to the average extent on October 28th over the last ten years when tracks converge is a factor of 1.6 lower than the strongest seven day recovery rate seen during that period. If the current level of sea ice extent occurs on October 2nd, then 26 days of the most rapid recovery seen in the last ten years would need to be maintained for 26 days to converge on the 28th. It is interesting to consider how that rapid sustained latent heat energy release might affect weather patterns. Would rain be made more likely relative to snow in central Canada or Siberia during this type of event? Examples in 2007 and 2011 might be worth a look.

    Comment by Chris Dudley — 18 Sep 2012 @ 6:30 AM

  313. Perk (#310) and Superman1 (#311),

    My script gives 0.3 C of further warming for a 30 year lag with turn around to cooling staring at about 2050. That is fairly close agreement with what Superman1 cites. I suspect that the effect of reducing sulphate aerosols is to cut the lag time leading to a slightly higher rise in temperature and a quicker turn around to cooling. I’m not entirely happy with my lag implementation but I do think that it captures the crucial aspect that the target is the instantaneous fast feedback climate sensitivity. There is no inertia in the sense that the oceans would keep on warming without an energy imbalance out of habit (momentum). The instantaneous curve is an attractor that pulls against honey-thick-drag (lag). There is no coasting. So, once that instantaneous curve indicates that the energy imbalance has reversed owing to reduced carbon dioxide concentration, then cooling starts with lag (drag) now applied in the opposite direction.

    This is really a mathematical investigation. Policy-wise, I think Hansen is correct that we will control climate through setting the concentration of carbon dioxide. Since cutting emissions to zero now hits his target concentration of 350 ppm around 2150, further emissions are required to maintain that target and not sink to 330 ppm. Substantial emissions are needed to achieve and maintain the popular 450 ppm target. So, cutting emissions to zero is not a realistic policy. If Hansen’s target is correct (and he is usually correct) there may be some scramble to soak up past emissions if it takes us too long to realize that. But, even so, we would be using the concentration of carbon dioxide as a tool. It is in our nature to make and use tools and this looks to be the most powerful we have ever made. Wielding it is irresistible really.

    Comment by Chris Dudley — 18 Sep 2012 @ 8:38 AM

  314. If the world is not warming as is suggested here http://elizaphanian.blogspot.co.uk/2012/09/those-odd-and-pesky-little-facts.html why is the sea ice melting? I’m not a sceptic but where did this data come from? I cannot decide whether the site Sam Norton links to is sceptic or not.

    [Response: It is a standard cherry pick - show only one record (which is obsolete) and pick the start point to give a misleading impression. The woodfortrees.com website allows you to play around with this kind of stuff. The point being that it is almost always possible to insist that the world is cooling when it is not, just by virtue of the weather noise in the system. This is a good demonstration of the tactic: http://skepticalscience.com/still-going-down-the-up-escalator.html - gavin]

    Comment by Neil — 18 Sep 2012 @ 9:17 AM

  315. > elizaphanian

    Sad to see that guy, whose blog is mostly about his personal faith and belief and reliance – mostly religious — has been relying on the “climate4you” site’s bogus claims.

    If he’s open to looking at facts, he’ll be changing his mind.

    Comment by Hank Roberts — 18 Sep 2012 @ 12:05 PM

  316. How about a time lapse animation for 2012′s Arctic ice melt?

    http://phys.org/news/2012-09-manhattan-sized-ice-island-sea.html

    Has a sliding bar at the bottom showing the months rolling by, and when it gets to July & August it melts incredibly fast! Also looks like what’s left is pretty whispy.

    Comment by Perk Earl — 18 Sep 2012 @ 1:50 PM

  317. Chris Dudley @ 313 wrote:

    “Since cutting emissions to zero now hits his target concentration of 350 ppm around 2150, further emissions are required to maintain that target and not sink to 330 ppm.”

    I have never gotten the impression that 350 is a goal we should *not* get _below_. My impression is that it is the *maximum* level of global atmospheric concentration we can hit and have some reasonable assurance that really bad things won’t happen. But even that is probably too high. Since during all of human civilization the level was never above 300ppm iirc, getting below that would seem to me to be the really rational goal to try to reach. If you have a clear passage that makes it clear that Hansen doesn’t think we should go below 350, please link it.

    Nuclear war heads are also a “tool,” but I, for one, am glad that we have managed to resist using them in war since WWII. Sometimes resisting what seems irresistible desires for control is the wisest route. At one point, Lovelock said that putting humans in charge of tending the global climate would be like putting a goat in charge of tending a garden–an apt comparison.

    Comment by wili — 18 Sep 2012 @ 7:32 PM

  318. The Hansen et al. paper expressing 350 ppm stated something to the effect of a maximum of 350 ppm and quite likely lower than that.

    My own estimate is that even 300 ppm is too high.

    Comment by David B. Benson — 18 Sep 2012 @ 8:07 PM

  319. 318 David B said, “My own estimate is that even 300 ppm is too high.”

    You had to know you’d be asked for clarification when you made that statement, so you’re probably well-prepared to answer my question: Say what??

    Comment by Jim Larsen — 18 Sep 2012 @ 9:30 PM

  320. wili (#317),

    You may be right that 300 ppm is better for now, and bringing emissions to zero and then capturing some past emissions would be needed to get there. I doubt that 300 is good over the next 10,000 years and we would want to adjust up to avoid glaciation over the Northern Hemisphere. And, recalling, that was the point Hansen was getting at. We won’t allow an ice age to happen since we can control that.

    Still, as a practical matter, a numeric target is going to be what we aim at and we may go along at 350 ppm for a bit before deciding on a new one and taking steps to control at the new level.

    If there is a god of goats, may it teach the goats some self-control so that we might learn from the example.

    As I recall, we did use a couple of nuclear bombs to end a war and then lots of nuclear tests to warn off an enemy, so we did wield them. Climate control will require much more cooperation than that though. Perhaps that would be a good thing.

    Comment by Chris Dudley — 18 Sep 2012 @ 9:57 PM

  321. Jim Larsen @319 — First of all, any such reduction is going to take a long time so there is plenty of time to research the preferred level. My prefer is to actually go enough below the preferred level to regrow ice sheets and glaciers to the extent practicable. We have good reason to suspect that such would occur at around 270 ppm. Then increase the CO2 concentration just enough to avoid a decent into a glacial (with a small safety margin). I suspect that about 285 ppm should do it for the next millenium or so.

    After that the orbital forcing begins to decline, so possibly lowering the CO2 concentration might be wise. In about 100,000 years the orbital forcing will make a serious and sustained stab at a glacial. That can be avoided by again rasing the CO2 concentration a little; I think Jim Hansen has suggested one modest CFC factory instead.

    Comment by David B. Benson — 18 Sep 2012 @ 11:03 PM

  322. David B, please answer on the Unforced V thread.

    Comment by Jim Larsen — 18 Sep 2012 @ 11:03 PM

  323. This article on arctic resources has some depth to it.

    http://www.nytimes.com/2012/09/19/science/earth/arctic-resources-exposed-by-warming-set-off-competition.html

    Comment by Chris Dudley — 19 Sep 2012 @ 7:49 AM

  324. Thanks for that response Gavin. I found the http://skepticalscience.com/ and found it very helpful of course as a scientist you always want a biggest data set you can get…

    Comment by Neil — 19 Sep 2012 @ 10:01 AM

  325. CD @ #320 wrote: “If there is a god of goats, may it teach the goats some self-control so that we might learn from the example.”

    LOL. Nice, thanks.

    Comment by wili — 19 Sep 2012 @ 11:49 AM

  326. So if we can stop beating each other up and get back to the science–this is the situation as I understand it: the large number of models that were used to predict future Arctic sea ice melt for the last IPCC report turned out to have predicted a vastly slower rate of melt than what we have actually seen in the succeeding years.

    For the work of these people to be of use at all, it seems to me that the important thing now is to figure out what factor or factors they overlooked or gave not enough weight to so that future models for both poles might be more accurate and yield more undestanding.

    Any ideas?

    It sounds like melting from below played a very large role in this season’s loss of volume. Was that figured in as a possibility? Are there good ideas about why and how exactly that happened? Did that warm water come from outside the Arctic? From super-heated surface waters flowing under the ice sheet? From deeper warmer and saltier layers of Arctic water getting brought up to the surface by whatever mechanism?

    Are there feedbacks that weren’t adequately accounted for?

    Did black carbon play a larger role than expected?

    Were the various effects of increased water vapor (both as a GHG itself, and as a source of snow that might insulate thin sea ice in early winter and keep it from getting thicker…) under-appreciated?…

    And while I’m barraging you good people with annoying questions: What in sam hill is going on with sea surface temperature in the Beaufort Sea, especially near the Alaska-Canada border?

    http://polar.ncep.noaa.gov/sst/ophi/color_anomaly_NPS_ophi0.png

    http://polar.ncep.noaa.gov/sst/ophi/color_sst_NPS_ophi0.png

    Comment by wili — 19 Sep 2012 @ 1:56 PM

  327. (The opening note above at 326 was a reference to the mudslinging going on in the open thread. We’ve been quite polite over here, I think–maybe too quiet??)

    Comment by wili — 19 Sep 2012 @ 4:07 PM

  328. regards 309 is this concept of the accelerated curve proven? It seems that the warming we have experienced is consistant with emissions up to approx 1982. surely the warming to 1.5C is already in the system regardless of future concentrations.

    Comment by DP — 19 Sep 2012 @ 5:03 PM

  329. http://scienceblogs.com/stoat/2012/09/18/wadhams-on-seaice-again/

    Comment by Hank Roberts — 19 Sep 2012 @ 10:21 PM

  330. RE: Wili, 326,327: Too quiet. I like that kind of probing attitude.

    In regards to your questions, here’s my thoughts & questions. Most of us have noticed that persistent open patch of water not too far from the North Pole. I’ve been wondering for a while now if that’s due to methane emissions. What would be interesting to find out is the water depth in that area in relation to other areas around it? Is it shallower? Also, the high water temps in the satellite photos near the coast, i.e. shallow water – is that due to methane emissions also? Could methane be the missing (feedback) factor in the inaccurate melt projections?

    Comment by Perk Earl — 19 Sep 2012 @ 10:50 PM

  331. Perk Earl: I think you are searching for explanations that aren’t needed. The ice is very thin this year. A large area of first year ice had drifted into the area where the hole appeared.

    No further explanation is called for. This year, virtually no first year ice has survived.

    Comment by Didactylos — 19 Sep 2012 @ 11:29 PM

  332. 326 wili said, “For the work of these people to be of use at all,”

    The amygdala is a region of the brain that is great for running away from potential predators. Make a mistake by running when you didn’t have to, and you’re out some calories. The converse mistake was fatal. Unfortunately, the amygdala is our enemy when logic is required. Once activated, it is designed to override all other input. One good example of the amygdala in action is Wayne D. Mention the n-word and he’s 100% running from the MegaLion. Just guessing here, but I sense some amygdala in your post.

    Models and scientists’ interpretations, which are not based solely on models by any stretch, are useful now, and will be useful in the future even if the amazingly hard task of building a virtual planet isn’t complete before the minimum hits 1 or 2. Ice free-ish isn’t game over, but game beginning. Remember when I did the 2012 ice area compared to the last decade as weighted by potential solar insolation? 2012 is average. You don’t start getting into serious albedo trouble until after the minimum gets way low. But ice-free-ish in September means we’ll need seriously accurate info on how quickly open water will spread towards June.

    Comment by Jim Larsen — 19 Sep 2012 @ 11:44 PM

  333. And if you’re going to blame anybody, blame computer makers. With a few orders of magnitude more processing power, scientists could make those models dance.

    Comment by Jim Larsen — 19 Sep 2012 @ 11:54 PM

  334. There is a claim now that the melt season is over: http://www.nytimes.com/2012/09/20/science/earth/arctic-sea-ice-stops-melting-but-new-record-low-is-set.html

    Comment by Chris Dudley — 19 Sep 2012 @ 11:57 PM

  335. On models,

    Several times I’ve read articles which say that scientists believe the inaccuracies in their models seem to arise from the size of their “boxes” – I have no idea how big they are, but if a box 100m across is needed to ‘capture’ an event, then if your boxes are 100km across, you’ll miss it, and there is no way to legitimately capture it using a bottom-up philosophy, as models do.

    So the options might be to wait for computers to get fast enough to allow for the capture of crucial events, or to use real world data to apply fudges which approximate those events. When informing policy-makers and the public, the latter seems smarter to me, with appropriate disclosure, of course.

    Comment by Jim Larsen — 20 Sep 2012 @ 12:33 AM

  336. wili @326,
    This paper was included in SkepticalScience’s round-up of new papers. I haven’t got round to reading it yet but it should throw at least some light on why modelling Arctic Ice levels is proving so difficult. (And semantics can easily add to all the difficulty so I will no more than mention that your use of the word ‘predicted’ @326 may not be entirely exact.)
    ‘Limitations of a coupled regional climate model in the reproduction of the observed Arctic sea-ice retreat’. Dorn et al 2012

    Comment by MARodger — 20 Sep 2012 @ 3:12 AM

  337. Over at NSIDC they’ve announced that the melt has probably maxed out on 16 September at 3.41 million square km, breaking the previous 2007 record of 4.17 million square km. That’s an 18% drop, or just over half the 1979-2000 average minimum extent. Here’s the most recent graph.

    Comment by Philip Machanick — 20 Sep 2012 @ 4:27 AM

  338. wili, to be fair, the best recent example of my amygdala taking control was my hyperbole about EVs spewing more carbon than fossil cars. It’s not an insult to say somebody has something which everybody has. It’s knowledge folks can use to override natural errors.

    Comment by Jim Larsen — 20 Sep 2012 @ 6:48 AM

  339. PE, much as I am concerned about methane, I don’t quite see how it could explain the bottom melt I was talking about. But maybe I’m missing something.

    Thanks for the link to the Stoat Blog, Hank. In the back-of-envelope calculations they do there, they don’t seem to consider anything but the effect from the change of albedo. Won’t a whole new open ocean also generate a lot of new water vapor, itself a GHG? Won’t that increase the effect on GW of a newly ice-free (or nearly so) Arctic Ocean? Or did they just leave that out because it’s in the nature of BoE calculations to just consider the most basic factor?

    [Response: Changes in water vapour in the Arctic go with the near-constant relative humidity, and occur mainly due to advection from lower latitudes, not local evaporation (except near the surface). The enhancement in LW absorption is certainly part of the feedback but there was a paper - I think by Jennifer Kaye et al on what makes the polar signal amplify relative to the globe - that found that the water vapour effect was not important - but I might not be remembering it completely. - gavin]

    Comment by wili — 20 Sep 2012 @ 8:31 AM

  340. Jim Larsen #335,

    “Several times I’ve read articles which say that scientists believe the inaccuracies in their models seem to arise from the size of their “boxes” – I have no idea how big they are, but if a box 100m across is needed to ‘capture’ an event, then if your boxes are 100km across, you’ll miss it, and there is no way to legitimately capture it using a bottom-up philosophy, as models do.

    So the options might be to wait for computers to get fast enough to allow for the capture of crucial events, or to use real world data to apply fudges which approximate those events. When informing policy-makers and the public, the latter seems smarter to me, with appropriate disclosure, of course.”

    This is a long-standing issue that is by no means confined to climate modeling. In many real-world complex systems, phenomena have to be incorporated that operate on both long and short time scales, and long and short spatial scales. Rather than wait for computer powert to increase sufficiently, one needs to be clever about choosing the appropriate grids to capture such phenomena. Grids that can adapt and place higher resolution in regions of large temporal and spatial gradients are preferable, albeit more complex.

    Equally important, incorporating critical feedbacks and capturing their synergy is mandatory to credible future projections. I don’t see the major models as having this capability yet, and their projections should be viewed as extremely conservative. My preference is to examine all the observations and trends we are seeing, think hard about the physics underlying these trends and where the feedback mechanisms could take us, then use our best judgment and the precautionary principle for future planning.

    Comment by Superman1 — 20 Sep 2012 @ 10:06 AM

  341. > the Stoat Blog

    Oh.

    You don’t know William Connolley’s writing, available both here at RC and there at his blog.

    Do the reading. Asking FAQS here about information available there shows you didn’t yet read what’s already written there.

    Take the time and effort, catch up, and after doing that ask thoughtful questions — questions that show you’ve already read what’s already been typed in and made available.

    Seriously. Take a week off from posting pointers to stuff you worry about — instead, read in depth there, while the end of the melt season happen and the conversations among those who placed bets about it discuss everything about how they’ve made their published guesses year after year. See how it’s been done.

    Google’s site search tool wants to be your friend.

    Comment by Hank Roberts — 20 Sep 2012 @ 12:17 PM

  342. I am disturbed by the constant demeaning of Maslowski and Wadhams on this site. It almost seems like the reaction of some little high school clique; they’re not in our club so let’s talk bad about them.

    Wadhams has been doing polar field research since 1969. Maslowski and the Naval Postgraduate School have a regional arctic climate model that takes into account many of the variables missing from GCMs – and at far better resolution.

    I really don’t know why there is always some snide remark at hand whenever these two names are mentioned. I would really like to see it stop.

    Comment by Kevin O'Neill — 23 Sep 2012 @ 4:57 PM

  343. The thread Pondering the Path To an Open Polar Sea in
    http://dotearth.blogs.nytimes.com/
    contains a short slide show well worth the time of anyone interested in artic sea ice.

    Comment by David B. Benson — 23 Sep 2012 @ 7:33 PM

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