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  1. One thing that’s important is to track what someone is measuring. Chapman/Walsh at UIUC focus on ice AREA while NSIDC estimates ice EXTENT. That’s one reason they have different findings at the moment.

    But everyone I talked to yesterday (Claire Parkinson, Mark Serreze, Walsh/Chapman, etc) agreed we’re in for a remarkable year. Polar bears and Arctic shippers beware.

    More on the implications here:
    http://topics.nytimes.com/top/news/science/series/thebigmelt/

    Comment by Andy Revkin — 10 Aug 2007 @ 8:17 AM

  2. I went on record last year – as an outside observer, of course – that summer Arctic sea ice will be gone completely within 5 years.

    Granted, that is not a scientific observation. It is more of a gut feeling that all of the conditions which contribute to the melt will continue to strengthen.

    Important to remember is that temperature will rise most rapidly in the polar regions, thus magnifying the overall effect. Also, the Arctic is an albedo-intensive region, and as the albedo rapidly shifts from positive to negative (do I have that right? From reflecting to absorbing), the pace of the melt must quicken.

    Would I be correct to conclude that the re-freeze each winter actually creates less ice than the year before? Perhaps the area is roughly the same, but the depth would be less, correct? Thus, the next summer’s melt can be even more rapid because there is less ice to melt.

    I see this as a self-enhancing feedback process, which is why I say that it will be extremely rapid.

    My question has been: what will the naysayers say when the Arctic, for brief periods, is essentially ice-free?

    Hmm?

    “Well, that’s not a bad thing. Look, now we have easier shipping lanes. Anyway, these things are cyclical.”

    In other words, it will be proof of something, just not AGW.

    Question for “group”: Will these observations regarding the rapidity of the melt lend any knowledge to the predictions of how quickly land-based ice might be set loose? We hear talk that the breakup of land-based ice could be much more rapid than previously speculated. Does the Artic sea ice melt inform that understanding in any way?

    Comment by Walt Bennett — 10 Aug 2007 @ 8:20 AM

  3. This shouldn’t really be a surprise; I wrote this on April 12th:

    What about the coming seasons? Last summer’s level was just above the record low. There was some recovery during the Autumn, but then the Winter level was also close to a record low. Normally, a less anomalous Winter would be expected to follow a Autumn ‘recovery’, but this year it didn’t happen that way. It is also worth noting that the period of maximum extent was in late February, rather than the more normal March, implying an earlier than usual shift in the seasonal influence. Given the already low level of Winter ice, the early onset of the thaw season, and the recent trends, it is reasonable to forecast that this year, the sea ice levels in the Arctic will hit a new record low. This is my prediction for the coming seasons. I have not mentioned other factors such as the Arctic Oscillation and Sea Surface Temperature Anomalies, though they have been considered in this forecast. The AO is broadly neutral at the moment, but may be shifting phase; the SSTAs are positive. Both of these influences are consistent with a forecast of low ie levels this year.

    You missed out the PolarView/Damocles site, which is also excellent, and the graphics magnify really well. There’s a link on my blog (sorry!).

    I’d like to ask if the areas of thin ice/open water to the north of N. Greenland and Ellesemere Island are unprecedented? Is there any record of there being open water here?

    Regards,

    Comment by Fergus Brown — 10 Aug 2007 @ 8:33 AM

  4. I need some perspective on this. What was the Arctic Ice extent in the 1930s? What was the extent during the Medievel Warm Period?

    Comment by VirgilM — 10 Aug 2007 @ 8:34 AM

  5. Each year the Arctic sea ice meltback appears more dramatic and prompts the obvious discussions on causes.

    I have tried for a year to persuade scientists to start a discussion on effects.

    For openers, it is obvious the greater expanse of open water eliminates more area of old ice. The new ice will be thinner, melt sooner and more easily break up with storm and wave action. So, it will be no surprise that the 2008 season will be a repeat of or surpass the 2007 meltback.

    But, what impact is that greater expanse of open ocean having on temp and precip in Western North America and more specifically in the world’s grain belt.

    The National Academy spent more than a year researching and publicizing abrupt climate change. Is it not of equal or, IMO, greater importance, to begin to answer the question: are we building the ethanol industry in a future dust bowl?

    The Arctic meltback has a great deal more to do with how the world will be fed than how polar bears will survive.

    Comment by John L. McCormick — 10 Aug 2007 @ 8:37 AM

  6. Re: Walt,
    What you are saying is very logical in most likely going to be correct.
    The re-freeze each winter will result in the ice depth getting thinner
    and thinner and also the edges of the polar region to shrink as well.
    From the 1960-1980 the rate of ice loss each decade was on average 1.4%,
    now in 2007 it is 7.8%. It is safe to assume that in the coming decade the
    loss of ice will escalate to 30-40%. So that probably well within 20 years
    we will have no permanet ice at all in the polar region. It’s a positive
    feedback mechanism.. the less ice and more dark coloured ocean the more
    heat that will absorb, melting even more ice…etc. The great oceanic conveyor
    is in real danger of slowing or stopping completely plunging europe, russia, china
    and canada and north america into a snap ice age.
    If everybody acted in a way as if thier lives depended on it(which it does)
    things would change..fast! Trouble is no one still seems to give a shit!

    Comment by Lawrence Coleman — 10 Aug 2007 @ 8:45 AM

  7. Climate Deniers = Climate Dodos

    “The Dodo (Raphus cucullatus) was a flightless bird that lived on the islands of Mauritius. Related to pigeons and doves, it stood about a meter tall (three feet), lived on fruit and nested on the ground.

    “The dodo has been extinct since the mid-to-late 17th century. It is commonly used as the archetype of an extinct species because its extinction occurred during recorded human history, and was directly attributable to human activity. The phrase “as dead as a dodo” means undoubtedly and unquestionably dead.” — Wikepedia

    Comment by Badger South — 10 Aug 2007 @ 9:03 AM

  8. Re: Walt, hmmm? if the great oceanic conveyor was to cease and down to the temperate latitudes were to
    freeze up…logic says that the polar ice cap might well return to normal thickness..or thicker? I’ll pass this to the
    group to discuss, they probably have more insights than me on this thought.
    There is ample evidence that the greenland ice shelves and glaciers are retreating and the pack ice thinning. Again the higher the temps in the region more of the rock beneath the greenland ice is exposed to the sun and the hotter it gets and will no doubt exellerate the rate of land ice melt raising sea levels.

    Comment by Lawrence Coleman — 10 Aug 2007 @ 9:05 AM

  9. Re: #6

    “If everybody acted in a way as if thier lives depended on it(which it does) things would change..fast!”

    Lawrence,

    Dr. Hansen is one of the most vocal of those who say that there is no way to quickly reverse the effects of AGW. Too much future warming has been built in.

    Things will get much worse before they get better, if we completely stopped adding to atmospheric CO2 today (which we can’t, and which the world won’t be able to do for at least a decade, more likely several decades).

    So, that’s a bit of fantasy on your part.

    However, “visuals” such as this should – SHOULD – get people to start hopping down off the fence, so that perhaps we can keep my estimate at the low end.

    Perhaps.

    Comment by Walt Bennett — 10 Aug 2007 @ 9:09 AM

  10. Re #8 where Lawrence wrote ‘… if the great oceanic conveyor was to cease and down to the temperate latitudes were to freeze up…logic says that the polar ice cap might well return to normal thickness..or thicker?’

    That is obviously correct, therefore it could not have been the halting of the oceanic conveyor (THC) that caused the rapid climate changes at the start and end of the Younger Dryas. It was the formation and disappearance of sea ice in the North Atlantic. The sea ice stopped and restarted the THC, not vice versa.

    The Arctic ice will not be able to reform this winter, because the climate in the Arctic will have been changed from pseudo-continental to maritime. Thus next summer, without any ice to reflect the sun away, the Arctic and the whole of the northern hemisphere will warm considerably, and the subsequent rapid climate change will lead to global famine since the farmers will have planted the wrong crops.

    What will the nay-sayers say then – they will blame the scientists!

    Comment by Alastair McDonald — 10 Aug 2007 @ 9:33 AM

  11. If anyone is interested in seeing what is happening at the North Pole NOAA have two web cameras there:
    http://www.arctic.noaa.gov/npole/2007/images/noaa2-2007-0803-065437.jpg
    Unfortunatly this one is sinking:
    http://www.arctic.noaa.gov/npole/2007/images/noaa1-2007-0804-010717.jpg

    For more pictures go to http://www.arctic.noaa.gov/npole/index.php?year=2007

    Comment by Alastair McDonald — 10 Aug 2007 @ 9:45 AM

  12. Folks:

    The National Snow and Ice Data Center (NSIDC) will be posting our first of a set of discussions and figures on 2007 sea ice conditions today (Friday, August 10). We’ll be providing updates each week (or as conditions warrant). We did this last year and got a lot of positive feedback.

    Comment by Mark C. Serreze — 10 Aug 2007 @ 9:45 AM

  13. Walt..i didn’t mean the climatic situation would change fast..as you said there is still 40+ years of all the pollution we have been emmitting to impact us..what I meant was public attitude would change fast. People would protest governments like never before for doing nothing..did I say George Dubblya? I mean if people realized this is life or death, things on a governmental and private sector level would change in the blink of an eye. Then if it isn’t already too late, the climate in maybe 80-100years time will slowly stabilise back to normal (for the last million years). Then if all the antacids people have been taking for climatically induced stress were dumped into the oceans their ph would resort to normal as well..

    Comment by Lawrence Coleman — 10 Aug 2007 @ 9:47 AM

  14. Are we whitnessing albedo flip (Hansen et al) right now? The graph from simulation runs (Hollan/Bitz/Tremblay) shows a dramatic drop once 4 million km2 september mean ice extent is broken. At this pace we will enter september well below threshold lining up for a dangerously low monthly mean.

    Comment by horrified observer — 10 Aug 2007 @ 9:58 AM

  15. Any answer to #4?

    Comment by interested observer — 10 Aug 2007 @ 10:04 AM

  16. Re #4 VirgilM, Check out the website:
    http://nwpi.krc.karelia.ru/climas/Ice/Ice_no_sat/XX_Arctic.htm

    It is much lower now than in the 1930′s.

    The medieval warm period was not as warm as it is now, based on Coral records and other proxies. So, it is unlikely that the ice extent was anywhere near as low as it is now.

    Why did you ask? If your interest is genuine you could find out the information yourself. I found the the above web site in 3 minutes. The second point, there were no satellites in the medieval warm period! I would suggest Lonnie Thompson may have more definitive work regarding that question.

    The people who run this web site are very professional and honest and do not peddle “spin”.

    They seem to be so busy with the like of you they rarely answer my questions.

    Comment by Lawrence McLean — 10 Aug 2007 @ 10:22 AM

  17. I believe the topic of a shut-down of the ocean conveyor belts has been exhaustively discussed in prior posts at this forum and the conclusion was it ain’t gonna happen.
    So, the trend will be more warming in the northern lats.; there ain’t gonna be an ice age for northern europe; and the arctic ice cap is going.

    Comment by rick — 10 Aug 2007 @ 11:11 AM

  18. As I’ve tried to point out before, there is a secondary effect to be considered as the reduction of sea-ice extent continues. That is, the outflow of sea-ice and surface water from the Arctic Ocean into the Greenland Sea.

    Each year, as the sea-ice melts, the surface water of the Arctic Ocean becomes freshened. That’s the result of salt rejection during the freezing process. That rejected salty brine tends to sink during the freeze season, adding to the Thermohaline Circulation. However, the fresh surface water that migrates into the Greenland Sea would tend to suppress the THC which has been seen to occur in that area. The net result may be a reduced THC overall and a shift in the path of the in flowing water from the North Atlantic. Should the sea-ice decline in extent continue, it is plausible that the flow or water into the Greenland Sea would increase and include more sea-ice than now passes thru the Fram Strait, as the sea-ice would no longer be the thicker, multi-year ice that is now seen in the area. The flow thru the Fram Strait continues along the eastern coast of Greenland, flowing into the Labrador Sea, which is another area of THC sinking. Thus, it is likely that the THC would be greatly reduced. There is also a flow of surface water and sea-ice thru the Canadian Archipelago into Baffin Bay and that transport would be much enhanced as the sea-ice cover is removed. These processes may already have happened in the late 1960′s, as seen in “The Great Salinity Anomaly”.

    There are those who have claimed that there is no need to worry about a reduction or shutdown of the THC. I suggest that this year’s changes present strong evidence which questions this conclusion.

    Comment by Eric Swanson — 10 Aug 2007 @ 11:27 AM

  19. I am not an expert on the Arctic, but it is a whole lot more interesting place than these posts suggest.

    First, normal sea water sinks as it cools, and thus normal ocean water freezes from the bottom up. Arctic sea ice includes a lot of freshwater that normally floats on the Arctic Ocean. Under the fresh water on its surface, the Arctic Ocean contains layers of warmer, saltier water, with very cold, very salty water in its depths.

    When the Arctic sea ice melts, it opens the surface water to mixing by storms, thus allowing the surface waters to become warmer and saltier. The additional salt in the surface waters means that they are likely to sink (into and through the warmer middle waters) as they cool rather than freezing at the surface.

    Thus, loss of Arctic sea ice not only changes the albedo of the Northern Hemisphere, it opens up a whole Pandora’s box of interesting physics.

    Here, that means that the arctic stops being a desert, and becomes a huge latent heat engine. Think about how much more lake effect snow is now being produced down-wind of Lake Erie, now that Lake Erie has a shorter freeze season, and think about the effects of less ice in the Arctic.

    Comment by Aaron Lewis — 10 Aug 2007 @ 11:27 AM

  20. re question from #2 Walt B.: “Will these observations regarding the rapidity of the melt lend any knowledge to the predictions of how quickly land-based ice might be set loose?”

    As I understand it, there is some similarity in the mechanisms. As sea water is darker than ice, so melt pools on the top of Greenland and Antarctic ice darken the surface. Also, warmer ocean water melts ice shelves from below, making them thinner, but the main thing here is a separate matter: they are then more likely to break up and “uncork” the land glaciers behind them. Even more different from the ocean situation, an important possible mechanism on land is that meltwater will sink to the bottom and lubricate glacier flow, speeding it up.

    Overall, I’d say that if Arctic Ocean ice disappears faster than expected, it will not tell us a lot about land ice, but it should reinforce the concern that we do not fully understand nonlinear effects that could make everything, not just land ice, change faster than current models predict.

    Comment by Spencer — 10 Aug 2007 @ 11:30 AM

  21. The New York Times article missed a little something, which was Siberia had a warm winter/Spring, with especially warm air aloft over that region, as to compared with the Canadian Arctic region. Which I was observing with fascination…

    Comment by wayne davidson — 10 Aug 2007 @ 11:48 AM

  22. Anybody know where one could find a composite graph of total global sea ice extent? I mean, there seems to be a million sq km positive sea ice anomaly in the SH, but whether this compensates for the big melt in the north is unclear. (Cryosphere today treats the hemispheres like two different planets.)

    Comment by Dodo — 10 Aug 2007 @ 11:52 AM

  23. Re: #21,

    If your implication is “maybe the warm Siberian winter/spring had something to do with warming conditions in the Arctic”, my rejoinder would be “what is the cause of the warm Siberian weather?”

    I would also ask you this: has some anomalous event been the cause of the Arctic warming for the last 30 years?

    In other words, when enough seemingly random events occur in a given period of time, and they add up to a trend, and that trend has not only been predicted but the eventual causes of the trend have been observed and measured for half a century…

    I find it very interesting to see how the denial machine handles this news.

    Comment by Walt Bennett — 10 Aug 2007 @ 12:22 PM

  24. I’m just an amateur, however has any consideration been given to the thickening of the troposphere and accelation of the polar jet stream as to why arctic ice may be disappearing quicker than what climate models have predicted?

    Over the last few years, it seems as though the polar jet stream is being diverted much further south than is customary. The result has been rather cool temperatures in the Northeast US from all that polar air. Understand that this is may also be due to a persistent high pressure system over Greenland.

    There is just so much cold air in the arctic and by emptying it out, that opens up pathways for warm air to enter that arctic from Asia…

    At least that is my pet theory.

    Thanks in advance.

    Comment by Andrew — 10 Aug 2007 @ 1:03 PM

  25. Re comments 4 & 10:
    Perspective is indeed important.
    There are studies showing past instances over last 130,000 years when Arctic was warmer than it is now and sea ice area smaller (particularly early in Holocene ~ 9k to 5k years ago and then the Eemian warm period between ice ages ~ 130k years ago).
    One recent story of mine explores how Arctic flora responded (very resilient):
    http://www.nytimes.com/2007/06/15/science/15arctic.html

    As for 1930s and Medieval optimum, Chapman at UIUC and others have some data, but doesn’t seem there was Arctic-wide retreat.

    The main reason this is significant news (to my mind) isn’t how it relates to the global warming trend, but more simply the reality that all that open water is starting to juice up the jockeying over who’s going to control the warming Arctic.

    Comment by Andy Revkin — 10 Aug 2007 @ 1:16 PM

  26. With the forthcoming Arctic melting, there will clearly be more ships in the Arctic, and I’ve seen general articles expressing general concern about the further acceleration of albedo-lowering from their soot.

    Does anybody have pointers to any more specific numerical studies about the relative effects of existing soot sources on the Arctic ice versus likely effects from shipping? Put another way, will controls (assuming any set of governments can agree on them) on Arctic shipping emissions help, or will they be essentially irrelevant by the time shipping there is substantial?

    Google: soot sources arctic ships
    didn’t find exactly what I wanted, but the following was interesting:
    http://www.polarcat.no/coordination/meeting-paris/meeting-materials/ppts/quinn_overviewArcticPollution.ppt

    Comment by John Mashey — 10 Aug 2007 @ 1:37 PM

  27. Here, that means that the arctic stops being a desert, and becomes a huge latent heat engine. Think about how much more lake effect snow is now being produced down-wind of Lake Erie, now that Lake Erie has a shorter freeze season, and think about the effects of less ice in the Arctic.

    Comment by Aaron Lewis

    Aaron, what happens if huge amounts of snow fall in the area around the Arctic Circle during the Arctic winter but stay on the ground until late in the Arctic summer when it all melts from the warmer temperatures? Wouldn’t that whole area be a cold wet desert in that case?

    Comment by catman306 — 10 Aug 2007 @ 1:37 PM

  28. ESA has much more interesting pictures of the density of the polar ice cover at:

    http://www.esa.int/esaCP/SEM7ZF8LURE_index_1.html

    Should have the 2007 comparison picture out in a few weeks…

    Comment by Miikka Raninen — 10 Aug 2007 @ 1:52 PM

  29. Re: 10

    > What will the nay-sayers say then – they will blame the scientists!

    Idi Amin: Yes, you are my advisor. You are the only one I can trust in here. You should have told me not to throw the Asians out, in the first place.
    Nicholas Garrigan: I DID!
    Idi Amin: But you did not persuade me, Nicholas. You did not persuade me!
    – The Last King Of Scotland

    Comment by Ezequiel Marti­n Camara — 10 Aug 2007 @ 2:37 PM

  30. #23 Walt

    With regards to Siberia being warm there is a simple explanation, once the Northern Hemisphere reaches a certain state of heat (energy), it does not lose it overnight. Heat radiation escapes to space at a constant rate, if the system cools from a higher state of heat at fall, during winter, eventually spring will be warmer, not necessarily at always the same geographic location since the Earth rotates.

    There is no anomalous event similar to this one, not in my about 25 winter seasons of observing from within the Arctic. There are years when synergystic combinations (as mentionned in the article) cause open water with relatively very small polynias, but nothing like a new ocean appearing before our eyes.

    Comment by wayne davidson — 10 Aug 2007 @ 2:38 PM

  31. Following up on Mark Serreze’s comment early. The NSIDC update is on the web at:

    http://nsidc.org/news/press/2007_seaiceminimum/20070810_index.html

    This will be updated once or twice a week through the rest of the melt season (end Sept or early Oct). It includes a daily image of extent and a timeseries of the seasonal behavior compared to climatology and previous low years. Looking at this, one can see that this year is quite stunning.

    A couple of notes:

    On area vs. extent – NSIDC uses total extent, which the total area covered by at least 15% sea ice. Area just counts up the area covered by sea ice. Thus, area values are lower since extent includes regions not completely covered by ice. Extent is a more robust value to use to compare to other years. Area estimates from the satellites can be biased by surface melt and atmosphere. This much less of an issue for extent, so it is more reliable to use extent.

    On earlier sea ice: It was quite warm in the 1930s, but the best data available indicates that we’re well below the extents in the 1930s. This could be due to a thicker overall ice cover back then that was more resistant to melt.

    Walt Meier
    Research Scientist
    National Snow and Ice Data Center

    Comment by Walt Meier — 10 Aug 2007 @ 2:54 PM

  32. Re: #31

    What is the best data available? When I looked at the UIUC material, it seemed like their view was that one should be cautious when using their pre-1953 data.

    Comment by interested observer — 10 Aug 2007 @ 3:06 PM

  33. re 27
    Did you ever see a lot of melting snow without a lot of mud? Did you ever see a lot of mud in a desert?

    That snow machine is driven by heat. Think of snow as a way to transfer heat from the warmer water to the air over the colder land. Just because it snows, that does not mean(all)the heat has gone away. The latent heat of the moisture from the water remains in the air.(Some of)that heat will come back as a warm wind or rain to melt the snow. Some of the heat will be radiated away. The point of Gavin’s 6 Aug. 2007 post was to help us understand how much heat will remain. (Excel is so much fun!)

    Comment by Aaron Lewis — 10 Aug 2007 @ 3:07 PM

  34. Andy Revkin (#25) wrote:

    As for 1930s and Medieval optimum, Chapman at UIUC and others have some data, but doesn’t seem there was Arctic-wide retreat.

    The main reason this is significant news (to my mind) isn’t how it relates to the global warming trend, but more simply the reality that all that open water is starting to juice up the jockeying over who’s going to control the warming Arctic.

    Likewise, in earlier periods, at least over the human history of the past 10,000 years, a warming of the northern hemisphere meant a cooling of the southern. It sea-sawed back and forth. But this time the warming is pretty much a global phenomena. The West Antarctic Peninsula is going, melts are occuring deep within the Antarctic interior, and the ice-mass balance of Antarctica is falling. There is cooling in some areas, but the net trend is the same.

    In human terms this is unprecedented.

    Comment by Timothy Chase — 10 Aug 2007 @ 3:41 PM

  35. Is there any connection between the very persistent low over the Gulf of Alaska and the rapid erosion of sea ice seen north of the Bering Sea?

    Comment by Karl Sanchez — 10 Aug 2007 @ 3:54 PM

  36. Re: #5

    I agree completely that we desperately need to talk about the effects of a rapidly warming Arctic on agriculture in the American Midwest.

    I think that not only are we building the roots of an ethanol industry in a very drought-prone region (and a region that may see less water as the Arctic warms), we are covering the Midwest in the same crops that covered the region in 1930 before major drought triggered the Dust Bowl. It seems to me that we’re asking for dust and trouble, albeit we haven’t ravaged the topsoil as badly as we had in the 1920′s.

    Can we quantify the danger of Arctic warming and reduced sea-ice in terms of North American precipitation? Are there any estimates of precipitation in the northern hemisphere is affected by Arctic warming?

    Comment by Travis O'Brien — 10 Aug 2007 @ 4:07 PM

  37. Karl Sanchez (#34) wrote:

    Is there any connection between the very persistent low over the Gulf of Alaska and the rapid erosion of sea ice seen north of the Bering Sea?

    I believe there is.

    A high pressure over the Arctic Sea is “pushing” sea ice out of the Arctic and into the subarctic where it tends to melt more quickly. If you look at the 30-day “movie” of ice distribution for the Northern Hemisphere at…

    Cryosphere Today
    http://arctic.atmos.uiuc.edu/cryosphere

    … you will notice that it is near the Bering Sea that the large swath of low-density sea-ice is concentrated and that it appears to be moving most quickly towards the Bering Sea.

    Comment by Timothy Chase — 10 Aug 2007 @ 4:20 PM

  38. re: #25, and the jockeying for sovereignty in the Arctic: what’s scary about it is that they are after the huge reserves of fossil fuels that have been inaccessible till now under the ice. Just imagine what happens if all of that CO2 gets churned out into the system!

    Comment by F Mackenzie — 10 Aug 2007 @ 4:22 PM

  39. Jeff Masters at Weather Underground has an interestingnew post on sea ice. Consider what he has to say about the impact of Arctic sea ice melt on global weather patterns:

    Loss of Arctic sea ice will also dramatically change the global weather and precipitation patterns. For example, the jet stream should move further north, bringing more precipitation to the Arctic, and more frequent droughts over the U.S. In any case, the reduced Artic sea ice should give us another delayed start to winter in the Northern Hemisphere this year.

    For me, this is the really big question. What does a rapidly melting Arctic do to NH weather patterns? The potential for dramatic shifts is obvious, but as far as I know only one group is trying to model this (Colorado?). Should be a rather urgent subject for research, I’d have thought…

    Comment by Gareth — 10 Aug 2007 @ 4:39 PM

  40. Very interesting Gareth. Here in Northwest Ohio, 5 of the last ten days have been over 90 F., with dewpoints up to 77 F. The meteorologists attribute it to high pressure keeping the jet stream north of the Northern US. This is what Jeff Masters has said was to be expected. I suspect this will become a new, unwelcome feature of our weather here.

    Oh. We’ve had many more days over 90 F here than normal, so far this summer.

    Comment by Jack Roesler — 10 Aug 2007 @ 4:47 PM

  41. re #36

    Regarding ethanol, you might be interested in the article by Jeff Goodell in the current issue of Rolling Stone.

    According to his report it’s a huge scam that has no real benefit for anyone … except certain special interests. Bad for the environment, bad for corn prices, just plain bad.

    Comment by J.S. McIntyre — 10 Aug 2007 @ 5:32 PM

  42. This is off topic, but the study out today on high cirrus clouds in the tropics is very interesting. I read it at http://blogs.usatoday.com/weather/2007/08/cloudy-forecast.html?csp=34. Their finding was fewer, not more clouds, thus more global cooling. However, I think this just makes the CO2 contribution to warming even stronger, as it would be warmer were it not for this negative feedback.

    Comment by Jack Roesler — 10 Aug 2007 @ 6:41 PM

  43. Walt Bennett (#2) said:

    My question has been: what will the naysayers say when the Arctic, for brief periods, is essentially ice-free?

    They’ll say the Arctic must have been ice-free in 1421, when the Chinese Navy circumnavigated Greenland.

    hey,, what is it with wordpress blogs and disappearing preview?

    Comment by llewelly — 10 Aug 2007 @ 7:05 PM

  44. re: 36, 41 Ethanol is OT in this thread…
    but as much as I enjoyed Goodell’s “Big Coal”, I think he hasn’t looked deeply enough into this, especially with regard to plausible trends, multiple studies with different numbers, use of switchgrass/miscanthus instead of corn, etc. Put another way, I think I give more credence to Argonne National Labs, UofI, Vinod Khosla, etc. Finally, recall that the petroleum industry has no reason whatsoever to like ethanol.

    Comment by John Mashey — 10 Aug 2007 @ 7:15 PM

  45. RE # 44 John Mashey

    Discussing ethanol is very much related to this thread if you have an interest in understanding the impact on North American temp and precip as the Arctic sea ice rapidly disappears during our mid-summer.

    Its simple: when you read ethanol, think grain. When you think grain, think global surplus. Then, you can factor that euphamism called ethanol into the thread.

    Comment by John L. McCormick — 10 Aug 2007 @ 8:06 PM

  46. Please note that on July 15, the English swimmer Lewis Gordon Pugh was able to *swim* 1 km in the North Pole exact location (google on this) – proving for WWF that there was enough free water to achieve this. This was impossible ten years ago (this crazy guy was just wearing a speedo in a -1.8°c water…)

    Comment by FredT34 — 10 Aug 2007 @ 8:12 PM

  47. There is, of course, more to sea ice than just its extent. Thickness, amounts of multi-year ice, etc, etc. What’s most interesting in these two images is the asymmetry of the areal reduction. Significant changes is the Laptev, Siberian, and Chukchi Seas; in the outflow areas of the Khatanga, Lena, and Kolyma rivers but not the same dramatic changes out from the McKenzie. What is going on here? Meanwhile, in the Greenland, Barents, and Kara seas more modest changes in area. Yet, again, in the Canadian lower Arctic archipelago significant changes. A perplexing pattern.

    Comment by Bill — 10 Aug 2007 @ 8:22 PM

  48. Hey guys, probably a silly question from a “still learning” guy. How are photo’s showing melting icecaps any different that the plots showing rising temperatures? I would expect that since the global temperature has risen between 79 and 07, that ice would melt. I would think, in order to add any new useful info, you would need to compare ice volumes with those of earlier hot years, like in the 30′s to help determine whether the ice is similar to what was going on then, or whether it has melted way more. Thanks for the informative blog. I find this place and ClimateAudit very interesting, I only wish there was less bickering and veiled shots taken at each other in the posts =D

    Comment by Technetium — 10 Aug 2007 @ 8:46 PM

  49. re “Climate Deniers = Climate Dodos…”

    Nice.

    Comment by Rod B — 10 Aug 2007 @ 9:35 PM

  50. re: #45 & OT

    I’d be delighted to see a Friday Roundup or specific topic called “Expected temperature and precipitation trends in the US & Canadian mid-west”….

    but turning *this* thread into an ethanol discussion is the kind of OT-amplification that eventually ruins a bulletin board.

    I’d expect there would be *many* other climate factors relevant to mid-West climate discussion than Arctic Sea Ice. From a quick look at the Index, I’d guess one could argue for an ethanol discussion in half of the topics (not even counting the Sheep Albedo Feedback), but that really doesn’t make sense.

    sci,energy has 4000+ hits for ethanol, might be a better place, or maybe there’s an RC-quality on fuels.

    Grain: I’ve heard of this stuff, having grown up on a farm with corn & wheat & oats. However, when I think about ethanol, I think ahead to switchgrass, miscanthus, or genetic-engineered versions thereof, as opposed to crops tuned for food for thousands of years.

    Comment by John Mashey — 10 Aug 2007 @ 9:41 PM

  51. I seems pretty likely the pole will be ice free (in summer) within a few decades if not sooner.

    I can’t help thinking that the first satellite picture of the ice-free arctic will be truly iconic, on a par with the first images of the earth taken from space/the moon. There’s no arguing with the idea that humanity can affect the planet when faced with something as concrete as that.

    Comment by SCM — 10 Aug 2007 @ 9:56 PM

  52. This is extremely frightening and alot of the comments here regarding theories corelates well with what we are currently seeing. It is currently like 55 in Upstate new york. It felt like October today but two states to the west of us, it’s nearing 100, (and well into canada I would presume.).

    I dont want to go much further into my thoughts because i dont want to upset the moderators of this blog, because I am not too too familar with the rules here as of yet. I read every blog, and most of the comments just don’t participate much because of this. I too would think maybe a forum of general climate discussion would be a great addition to this database of reliable climate discussion and information.

    Although, this I believe I can add without hesitation. On the topic of a colder Northeast, I already made the point above that it is extremely cool here lately, and we seem to be espcaping most of the high heat, but If my memory serves me correctly, last year the same type of trend occured, we’d get heat, then cool for a while then intense heat back and forth. Along with it, I’ve noticed it seems that during the fall (this at least for the past couple years now) the temperatures stay much milder, giving an opprtunity this past christmas to wear a short sleeved shirt, the year before was a nice warm day as well for Christmas. I also saw a baby bird on january 5, 2007 this year, outside my window while taking down christmas decorations, in the meanwhile, the rest of the country was dealing with the cold and heavy snows, and not to mention the erratic weather. El Nino was said to be of blame, but this trend has been progressive over the past few yeras. Many locals notice the shift in seasons in the Northeast as well. We seem to get better chances for severe weather in the fall similar to the midwest (not in terms of frequency, but intesity). Albany New York had a Tornado watch out on Dec 1st 2006. Maybe one of the handful of times theres ever been the word Tornado and watch or warning in this area, and decemeber of all months.

    Just my 50 cents to add to several posts above related to less artic ice effects on weather, IE the Northeast. I would only imagine from the trends and what I have read about it, that this would continue.

    Comment by Chris S — 10 Aug 2007 @ 11:07 PM

  53. Re #33: [Did you ever see a lot of melting snow without a lot of mud?]

    As a matter of fact, yes. It’s quite common around here (east slope of the Sierra Nevada). Porous decomposed granite soils without much organic matter, low humidity, and large day/night temperature swings means that meltwater either soaks in or evaporates almost immediately (if it doesn’t actually sublimate), so the ground just gets sort of damp.

    Comment by James — 10 Aug 2007 @ 11:46 PM

  54. I am curious, as we are discussing this absolutely startling rapid melt of the arctic sea ice, where the discussion of permafrost and methane enters into the equation. It would seem to me that with all the extra heat in the arctic, both atmospheric and ocean, that permafrost would also be thawing out rapidly, and we might be seeing a continuation of the rapid rise in methane that we’ve seen the last 20 years, (though it was flat to slightly lower the last 2 or 3)? Any experts here care to discuss potential permafrost/methane connections to an ice free Arctic Ocean?

    Comment by R. Gates — 11 Aug 2007 @ 2:11 AM

  55. Re #51 The North pole is already free of ice in the summer. In fact a Briton has been swimming there this summer to raise awareness of climate change, but he seems to have had little effect :-(

    See http://news.bbc.co.uk/2/hi/uk_news/england/london/6899612.stm

    In fact it was first free of ice in the summer of 2000.
    See http://news.bbc.co.uk/2/hi/americas/888235.stm

    But the ‘powers that be’ forced the New York Herald to withdraw that story. Things are a lot worse than you are allowed to know.

    Comment by Alastair McDonald — 11 Aug 2007 @ 3:59 AM

  56. Re 48. Different people have different modes of neural processing, well described in the literature on neural linguistic processing. To many people, showing a graph is a waste of time. They don’t know how to interpret graphs; they haven’t had the training, and so it is not a surprise. Showing a picture however can be very powerful, especially if two pictures are shown as before and now. That leaves the person to whom the pictures are shown with the problem (or opportunity) of thinking about what the picture for the ‘after’ condition might look like.

    The real problem, though, is how to get over the problem of the failure of climate scientists to deliver absolutely clear messages to the world about the potential for sea level rises of the order of metres over the coming decades. The IPCC has demonstrated failure in that regard, and has run away for 6 years. Perhaps it should be re-convened on a 12-monthly basis specifically for the emergency topic of sea level rise.

    The world is probably justified in thinking that the potential sea level rise over the next century is a few inches or, for those who don’t do inches, a few centimetres. Climate scientists, or those who give themselves that description, will mumble to each other. What might they say? Perhaps a discrete conversation over coffee might go along the lines:

    Climate Scientist A: “we know it’s not a few centimetres”
    Climate Scientist B: “we are reticent, we can’t go public”
    Climate Scientist A: “oh, leave it to Hansen, he’ll do the going public bit”
    Climate Scientist B: “but will we still get funding and will we still be able to publish our work in peer-reviewed journals?”
    Climate Scientist A: “oh yes, we can tell them that the rise will be a few centimetres but then add a bit on the end to cover our arse”
    Climate Scientist B: “what bit will that be?”
    Climate Scientist A: “we’ll add the phrase … but it could be more”
    Climate Scientist B: “oh … that means we are covered when the ice sheets do start to disintegrate”
    Climate Scientist A: “you got it!”

    The time for reticence is over. The world needs a clear message.

    For example, where can the public find the results of a Delphi study of the world’s top 100-500 climate scientists’ estimate of what sea level rise might be up to 2100?

    Comment by Michael — 11 Aug 2007 @ 4:39 AM

  57. Yes indeed, what is going on in the Arctic sea ?!?

    Have a look at:
    http://www.servumpecus.canalblog.com/archives/2007/08/05/

    With my best regards,
    Servumpecus

    Comment by Servumpecus — 11 Aug 2007 @ 4:48 AM

  58. Meanwhile, sea ice coverage at the south pole is above average. Does RC have any posts discussing expected trends in southern hemisphere sea ice ?

    Comment by David — 11 Aug 2007 @ 6:32 AM

  59. re 56

    “The time for reticence is over. The world needs a clear message.”

    Michael, have you seen the report of the joint study by Sigma XI and the United Nations Foundation? Entitled “Confronting Climate Change: Avoiding the Unmanageable and Managing the Unavoidable”, it strikes me being as along the lines of what you are asking for.

    http://www.sigmaxi.org/about/news/UNSEGReport.shtml

    I think the real problem is that unless you read American Scientist magazine, or follow the proceedings of the UNF, John Q. Public is not going to know it exists. Which, IMHO, is the real problem. I think the climate scientists have been rather clear in their message.

    It’s the media. On one hand, they muddle the issue by allowing themselves to be manuevered into suppounding the “It’s a debate” promoted the denialists (Dodo-ists?), most likely because conflict sells more papers than conclusions. Second, again related to selling papers in an era where readership is declining, they are more interested in letting us know what and who Brittney, Lindsey and Paris are running their automobiles into, detailing the latest tragic family slaying, repeating teh latest al Qeada warning. Something like the oncoming climate disaster, supposed to happen far in the future and with no Katrina to make it current and “sexy” just isn’t selling papers.

    So John Q. Public (re Joe Six-Pack & Matilda Make-up) haven’t heard the news and likely wouldn’t pay attention if they did.

    Now if only some poor, starving Polar Bear ate Paris Hilton, maybe the issue would get some press…

    *sigh*

    Comment by J.S. McIntyre — 11 Aug 2007 @ 9:34 AM

  60. Question (one of those wake-up-in-the-middle-of-the-night kind).

    In 2005 and, I think, 2006, the ocean currents off Northern and Central California were much warmer than expected. Combined with weak upwelling, the zooplankton production dropped precipitously, in some areas to 14% of normal, if I’m remembering correctly, which led me to wonder:

    Has anyone done any projections of biomass levels for the Arctic seas over the next year based on what’s happening? (I’m assuming they have, given 2005′s ice retreat).

    Also, of course, is there some sort of correlation between what California currents from the north experienced in 2005 (and 2006) and the decline of sea ice in the Arctic?

    Thanks in advance.

    Comment by J.S. McIntyre — 11 Aug 2007 @ 9:48 AM

  61. re 50 (and #45 & OT)

    I’d be delighted to see a Friday Roundup …
    =========================

    Agreed. That said, regardless of your feelings for the author, you should read it. The problems associated with ethanol are fairly straightforward, and laid out well. And switchgrass is not a solution, particularly once you factor in land use, transportation and processing costs. And this isn’t even factoring in the energy efficiency figures versus the cost of bringing home the bacon.

    The real problem, IMHO: it’s a panacea, a short-term, likely unsustainable effort that does little more than give the appearance of “doing something” when, in fact, it’s actual positive effect is negligible, while the negative is large (You’ve heard of the “tortilla crisis”, right?) in terms of higher corn prices and lost land better used for food production.

    That said, I’ll shut up and worry about something more in line with the subject, like how the warming Arctic will affect the ocean’s ability to produce food.

    Comment by J.S. McIntyre — 11 Aug 2007 @ 9:58 AM

  62. re 58:

    Meanwhile, sea ice coverage at the south pole is above average. Does RC have any posts discussing expected trends in southern hemisphere sea ice ?

    ========================

    Could you provide a link to this? I’m personally curious as my wife is journeying to the Ross Sea in February…

    That said, I believe Timothy Chase said something contrary to what you are saying in #34. Hopefully this will get sorted out.

    Comment by J.S. McIntyre — 11 Aug 2007 @ 10:03 AM

  63. David in 58 remarked:
    “Meanwhile, sea ice coverage at the south pole is above average.”

    Yeah, and there is no Sun in the South pole at the moment.

    Besides, there is neither obvious trend nor alltime record maximas/minimas in Southern Sea Ice Area data. See:
    http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/current.area.south.jpg

    Comment by Petro — 11 Aug 2007 @ 10:03 AM

  64. Its too bad we can’t compare the last equivalent weather situation, 1934 for instance. But, satellite technology being what it is takes getting satellite date from that period a little difficult. My grasp of the obvious.

    Comment by CoRev — 11 Aug 2007 @ 10:25 AM

  65. Re 54- R. Gates raised the question about methane release and permafrost melting because of the extra heat in the Arctic. I have been watching with concern the temperature anomaly off the NE Siberian coast, which has persisted for weeks, seen here:

    http://weather.unisys.com/surface/sst_anom.html

    Surely this portends more rapid disintigration of the Siberian permafrost coastal shelves, with the attendant release of methane. Am I correct in recalling that there are substantial methane hydrates included in these structures?

    Comment by Ron Taylor — 11 Aug 2007 @ 10:42 AM

  66. JS McIntyre (#62) wrote:

    That said, I believe Timothy Chase said something contrary to what you are saying in #34. Hopefully this will get sorted out.

    Nope.

    He was speaking strictly of sea ice. (#58) I was speaking of glaciers and some parts of the interior of the Antarctic, but made no mention of sea ice. (#34)

    As I have pointed out previously, if Antarctica were to experience a sudden loss of glaciers, you would expect an increase in sea ice, not a decrease.

    However, Petro is right (#63) – no obvious trend in sea ice.

    I am curious, though: how were you able to know the number of my post? I assume you looked it up, but this doesn’t make any sense given the fact that the two posts were clearly speaking of different things, and both posts were short enough I presume the difference would have been obvious.

    Comment by Timothy Chase — 11 Aug 2007 @ 11:26 AM

  67. Alastair McDonald (#55) wrote:

    Re #51 The North pole is already free of ice in the summer. In fact a Briton has been swimming there this summer to raise awareness of climate change, but he seems to have had little effect.

    See http://news.bbc.co.uk/2/hi/uk_news/england/london/6899612.stm

    In fact it was first free of ice in the summer of 2000.
    See http://news.bbc.co.uk/2/hi/americas/888235.stm

    Now that is a dramatic detail!

    Something which bears repeating – particularly in essays.

    But the ‘powers that be’ forced the New York Herald to withdraw that story. Things are a lot worse than you are allowed to know.

    It should be obvious how bad things are to anyone reading the headlines who has a wit of common sense – given the power struggle that is beginning to be waged by Russia, Canada, US, Sweden and the Netherlands over the Arctic Ocean oil reserves. Fighting over oil under these circumstances! Someone must have a perverse sense of humor.

    Comment by Timothy Chase — 11 Aug 2007 @ 4:56 PM

  68. re: #61 OT
    “Agreed. That said, regardless of your feelings for the author, you should read it. The problems associated with ethanol are fairly straightforward, and laid out well.”

    ?? Peace: you seem to be reading something other than what I posted.

    I have previously recommended Jeff Goodell’s “Big Coal” several times (hence, if anything, I’m favorably disposed), but I didn’t think his RS piece (which I’d read before I commented) was up to that standard. Robert Rapier’s blog is way more informed and balanced, with well-nuanced discussions (including some agreement/disagreements with Khosla) but that doesn’t come through very well in JG’s RS piece.

    For example, RR says: “I firmly believe we should be aggressively researching the potential of cellulosic ethanol…But I think the hype has gotten way out of touch with reality at this time.” *That* is good, albeit a tiny sample of fairly complex discussions there.

    Anyway, back to Arctic ice, please; let’s take this ethanol stuff to i-r-squared.blogspot.com or some other more relevant place.

    Comment by John Mashey — 11 Aug 2007 @ 5:13 PM

  69. Freeman Dyson cast some interesting doubts (as heresies) about the climate modeling in GW on the Edge website here:

    http://www.edge.org/3rd_culture/dysonf07/dysonf07_index.html

    He isn’t claiming GW is untrue, just possibly too reliant on poor models.

    Any comment about this?

    Comment by Alex Tolley — 11 Aug 2007 @ 5:19 PM

  70. Re 66,62,63 – The cryosphere today website has a graph of current sea ice coverage over the last year in both the Arctic and the Antarctic, together with the current difference from the 1979-2000 mean value. The difference from the mean is obviously corrected for the time of year. In the Antarctic it currently shows about 0.6million square kilometres more ice that the mean.
    In my original post I was merely asking for intelligent comment on the future of antarctic sea ice.

    Comment by David — 11 Aug 2007 @ 6:24 PM

  71. I imagine nobody else noticed but the NOAA and the NCDC changed the historic sea ice extent data in January of this year. The changes were very, very substantial.

    If you want a BEFORE and AFTER, here is link to gif image.

    http://img401.imageshack.us/img401/2918/anomalykm3.gif

    As well the best place to look at sea ice extent is using the VISIBLE satellite picture from AQUA/MODIS/TERRA satellites. These VISIBLE real-time images show there is more arctic sea ice than shown by the NCDC and the Cryosphere Today.

    http://rapidfire.sci.gsfc.nasa.gov/realtime/

    Comment by John Wegner — 11 Aug 2007 @ 7:19 PM

  72. In the data collected by National Snow and Ice Data Center, University of Colorado, Boulder, CO.

    http://nsidc.org/seaice/characteristics/difference.html

    The melt and recovery show that the total Arctic Ice in manner of Millions of sq. miles. It lists it’s data as being about the same. How is the pack getting smaller if the recovery level and the melt level are consistently the same? Can anyone help me here?

    Comment by hoosiernorm — 11 Aug 2007 @ 7:55 PM

  73. John Wegner (#71) and hoosiemorm (#72),

    I believe it might help everyone to check out a chart showing Northern Hemisphere Sea Ice Extent which has not been updated to include 2006. (Unless you are suggesting they went back and edited this image as well, John – but this would seem to imply intent.) This is done seasonally…

    Northern Sea Ice Extent
    http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/seasonal.extent.updated.2005.jpg

    For John, here is another image from 2005, albeit based on annual trends..

    28 September 2005
    Sea Ice Decline Intensifies
    Figure 1: September extent trend, 1978-2005
    http://nsidc.org/news/press/20050928_trends_fig1.html

    As well the best place to look at sea ice extent is using the VISIBLE satellite picture from AQUA/MODIS/TERRA satellites. These VISIBLE real-time images show there is more arctic sea ice than shown by the NCDC and the Cryosphere Today.

    http://rapidfire.sci.gsfc.nasa.gov/realtime/

    John, somehow I don’t think the images of the Arabian Peninsula will be very helpful.

    Comment by Timothy Chase — 11 Aug 2007 @ 9:05 PM

  74. Re: Post #65

    I have only recently become more interested in the methane part of the equation, and certainly the great unknown (isn’t it all though really?) is how quickly the permafrost will respond to the temperatures associated with a summertime ice free arctic.

    Does anyone know where we can get reliable and near real-time atmospheric methane concentrations for various parts of the planet? I think the reponse of permafrost and perhaps even methane caltrates in the deeper (and warmer ocean) would be of keen interest considering how potent a GH gas it is.

    Comment by R. Gates — 11 Aug 2007 @ 10:25 PM

  75. ftp://sidads.colorado.edu/pub/DATASETS/PASSIVE_MICROWAVE/POLAR_STEREO/ANCILLARY/ICE_EXTENT/SMMR-SSMI_BOOTSTRAP/BROWSE/gsfc.bootstrap.extent.Total-Arctic.1978-2004.n.gif

    So is the Colorodo Chart Wrong?

    Comment by hoosiernorm — 11 Aug 2007 @ 11:06 PM

  76. [[Freeman Dyson cast some interesting doubts (as heresies) about the climate modeling in GW on the Edge website here:
    http://www.edge.org/3rd_culture/dysonf07/dysonf07_index.html
    He isn’t claiming GW is untrue, just possibly too reliant on poor models.
    Any comment about this?
    ]]

    Yes. Freeman Dyson is given to making extravagant claims in fields he isn’t really familiar with.

    Comment by Barton Paul Levenson — 12 Aug 2007 @ 6:14 AM

  77. On 10 August 2007, NOAA data showed the direct Northwest Passage through the McClure Strait north of Banks Island to be completely open. I’ve scanned the recent data and cannot find a precident (though 1998 and 1999 go very close).

    The historic plot is here: http://polar.ncep.noaa.gov/seaice/analysis/nh/nh12.20070810.gif

    [The previous direct NWP minimum appears to have been ~20 Sept 1998: http://polar.ncep.noaa.gov/seaice/analysis/nh/nh.19980920.gif ]

    Comment by Glen Fergus — 12 Aug 2007 @ 6:38 AM

  78. #73 – Timothy Chase – the MODIS/TERRA/AQUA satellites are in a polar orbit and take pictures every 5 to 10 minutes. Click on one of the images and you can use the Prev and Next buttons on the side to move back and forth in the orbit to see the North Pole or just about anywhere on the planet in real-time or in the last 24 hours at least.

    The images also allow you to use different wavelengths and Zoom into 4km, 2 km, 1 km, 500M or 250M resolutions.

    Here is the 4 km Visible image of the Siberian side of the Arctic ocean including the North Pole from about 10 hours ago (remember 24 hours of sunlight in the Arctic circle this time of year.)

    According to the Cryosphere Today software-produced image in this thread, there is supposed to be very little sea ice here whereas obviously there is (Note clouds are sometimes in the way but if you go back and forth and look at other images you can directly see with your own eyes whether there is sea ice or not.)

    http://rapidfire.sci.gsfc.nasa.gov/realtime/single.php?2007223/crefl2_143.A2007223234001-2007223234500.4km.jpg

    Comment by John Wegner — 12 Aug 2007 @ 7:37 AM

  79. Rapid Sea Level Rise of 500mm per decade is possible, its not a question of if but when. We can all see the process starting now in which the melting will facilitate the cascade of the land based ice into the sea, giving the general public a bit of a shock. I think we will see the start of the cascade in a decade or two, I hope not. What I think needs to be discussed is the preparation for such an event, being early is not a problem, more than anything it will help society move into the next stage of civilisation. Their are a lot of things to do, but I would just like to mention one. Nuclear power stations on the coast line do pose a bit of a problem, especially the ones being planned now. Decommissioning will not be possible when the cascading takes effect as the sea level rise will be rapid and unforgiving. Renewable energy can work, especially the CETO technology being developed in Perth Western Australia. A lot of things can be done about climate change, I just wonder what path we will all take.

    Comment by Simon Edmonds — 12 Aug 2007 @ 7:45 AM

  80. Re 79. In addition to potential burial-at-sea of nuclear reactors there is also the potential for wash-out of thousands of toxic dumps. Potential dislocations spreading through global supply chains during this process may have a high impact on decommission and rebuild capacity. The situation requires urgent international attention.

    Comment by Michael — 12 Aug 2007 @ 9:40 AM

  81. Re # 19 Aaron Lewis
    “normal sea water sinks as it cools,”
    No argument there.

    “thus normal ocean water freezes from the bottom up.”
    Not normally, it doesn’t. As the upper layer of water cools and approaches its freezing point (in contrast to fresh water, in seawater the freezing temp equals the temperature of maximum density), the sinking (downwelling) slows – the layer of water at the surface is in contact with the colder atmosphere and starts to freeze first, with ice crystal formation causing it to expand. Hence, ice freezes at the surface, just as it does in fresh water. Brine rejection by the ice will add salt to the underlying water and cause downwelling under the ice, but that is a gradual process. If you were thinking of anchor ice formation, that occurs only in very specific situations (http://en.wikipedia.org/wiki/Anchor_Ice; http://amsglossary.allenpress.com/glossary/search?id=anchor-ice1)

    At least is how I understand it.

    Comment by Chuck Booth — 12 Aug 2007 @ 11:46 AM

  82. # 81 I should have said ice forms at the surface, just as it does in fresh water.

    [Response: That is overwhelmingly the case, but curiously you do sometimes get ice forming at depth when supercooled water from underneath ice sheets moves into the open ocean. I think it's sometimes called 'marine ice' . - gavin]

    Comment by Chuck Booth — 12 Aug 2007 @ 11:47 AM

  83. re 66

    That said, I believe Timothy Chase said something contrary to what you are saying in #34. Hopefully this will get sorted out.

    Nope.

    He was speaking strictly of sea ice. (#58) I was speaking of glaciers and some parts of the interior of the Antarctic, but made no mention of sea ice. (#34)

    ==============

    I note you didn’t seem to have a problem with David’s remark “Meanwhile, sea ice coverage at the south pole is above average” when, in fact, there is no sea ice at the south pole, or any within hundreds of miles.

    I bring this up not to be contentious, but to underscore that you did mention the West Antarctic Pennisula in #34 (“The West Antarctic Peninsula is going”), where a great number of glaciers are emptying into the sea, which was where I made the association, as I tend to think of the sea surrounding the territory as part of the area. I didn’t think I needed to be clearer, but in retrospect, I should have.

    My apologies.

    Comment by J.S. McIntyre — 12 Aug 2007 @ 12:17 PM

  84. J.S. McIntyre (#83) wrote:

    I note you didn’t seem to have a problem with David’s remark “Meanwhile, sea ice coverage at the south pole is above average” when, in fact, there is no sea ice at the south pole, or any within hundreds of miles.

    I bring this up not to be contentious, but to underscore that you did mention the West Antarctic Pennisula in #34 (“The West Antarctic Peninsula is going”), where a great number of glaciers are emptying into the sea, which was where I made the association, as I tend to think of the sea surrounding the territory as part of the area. I didn’t think I needed to be clearer, but in retrospect, I should have.

    My apologies.

    Not a problem.

    I myself keep reading over what I am about to post, but maybe a little too quickly. It is only after I go back that I will notice that some sentence is garbled, usually either near the very beginning or end of the post. The beginning is worse as this is what people are likely to read first. But it is usually at that point that the mind is still in the process of tuning up, sorting out your thoughts, trying to put everything into context. It is only later that you know exactly what it is that you want to say.

    Then of course there are the misinterpretations of what other people have said, of their intent, responding to what you think they have said or what you think was the intent behind their words. I enjoy participating, trying to take into account everything I can, but I probably don’t measure up to what I would like most of the time.

    Sometimes I will respond to what someone else has responded to, but typically in more detail because I am still trying to get everything straight in my own head. Different responses will probably speak to different people, longer responses to some, shorter and more direct responses to others. As such I don’t see a problem with different people responding to the same post.

    But sometimes I wonder whether this too might be misinterpreted – as if I think that I am in some sort of a contest with others. But it most certainly isn’t a contest, at least as I see it. I just think that everyone should do the best that they can and not worry too much about the rest.

    Anyway, this is probably more personal detail than most will care to hear. But I figure some will find some value in it simply in terms of being able to see what others are probably going through. There is a great deal at stake, and I am sure the emotions often run high for others as well as myself.

    Comment by Timothy Chase — 12 Aug 2007 @ 1:25 PM

  85. The remarkable point in Arctic sea ice extent is not that it is lower by the year in summer (and in yearly average), it is that winter sea ice cover hardly declined from the long-term average.
    See the seasonal trends here.

    Thus in winter, most of the summer melt refreezes. Why is that? In summer there are more clouds than in the past. This reduces the influence of the sun (or the melting would be larger). In winter the reverse happened: less clouds than usual, thus with more open skies during polar night, more heat radiation escapes to space and water freezes more rapidly.
    See Science”

    Something that climate models didn’t expect…

    Comment by Ferdinand Engelbeen — 12 Aug 2007 @ 2:12 PM

  86. Ferdinand said:
    “The remarkable point in Arctic sea ice extent is not that it is lower by the year in summer (and in yearly average), it is that winter sea ice cover hardly declined from the long-term average.”

    Contrary to your claim, there is a shrinking trend in winter sea ice cover starting around 1972. Dramatic drop has occured during last four winter. See: http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/current.area.jpg

    Comment by Petro — 12 Aug 2007 @ 4:23 PM

  87. Re # 19 Aaron Lewis
    “Think about how much more lake effect snow is now being produced down-wind of Lake Erie, now that Lake Erie has a shorter freeze season”

    I don’t know about recent changes in lake effect snow due to warming to date, but lake effect snow on Lake Erie’s Southern shore (and that of the other Great Lakes) is predicted to decrease by the end of the century due to global warming:

    The Future of Lake-Effect Snow: A SAD Story
    From Acclimations, January-February 2000
    Newsletter of the US National Assessment of
    the Potential Consequences of Climate Variability and Change

    By Peter J. Sousounis, The University of Michigan

    [Excerpt]
    “Recent simulations from the Canadian Model (CGCM1) and the United Kingdom Hadley Model (HadCM2) suggest that the climate in the Great Lakes region by the end of the 21st century will be warmer and wetter — with the CGCM1 being warmer and drier than the HadCM2 (4 vs 2°C and 25% increase vs 50% increase). While understanding the mean temperature and precipitation changes predicted by the models is important, day-to-day weather will be affected by corresponding changes to cyclone tracks, arctic outbreaks, and lake-effect snow patterns. In predicting these crucial day-to-day local aspects of the weather, even the current suite of GCMs is inadequate. However, some conclusions about the local weather patterns can be made with confidence by understanding the connection between the large scale flow patterns and local weather. In this respect, both models are more similar and suggest that by the end of next century, the typical winter may be comparable to what we experience now during a moderate-to-strong El Nino. The coldest winters may be comparable to what we experience now in a normal winter. Snowfall totals may therefore be half the current normal totals with lake effect snow being significantly reduced, especially over the southern portions of the region where average temperatures barely support snow now. Both the CGCM1 and the HadCM2 suggest a more zonal flow pattern, meaning more Pacific systems, fewer Gulf of Mexico systems, and fewer Alberta Clippers. Alberta Clippers are a primary source for reinforcing the cold air over the Great Lakes in winter. Fewer outbreaks likely means less lake-effect snow.

    Impacts on recreation
    Less lake-effect snow could potentially have a considerable impact on the winter recreational activities of the region — particularly in the southern portions, where significant reductions in snowfall totals coincide with populous urban centers like Chicago, Detroit, Cleveland, and Buffalo. …”

    http://www.usgcrp.gov/usgcrp/Library/nationalassessment/newsletter/2000.02/Lakefx.html

    Comment by Chuck Booth — 12 Aug 2007 @ 8:54 PM

  88. Re 69. Freeman Dyson writes at that link “The most alarming possible cause of sea-level rise is a rapid disintegration of the West Antarctic ice-sheet, which is the part of Antarctica where the bottom of the ice is far below sea level. Warming seas around the edge of Antarctica might erode the ice-cap from below and cause it to collapse into the ocean. If the whole of West Antarctica disintegrated rapidly, sea-level would rise by five meters, with disastrous effects on billions of people.”

    Freeman Dyson suggests that we are relying too much on models.

    Where are the models of ice sheet disintegration that the world is relying on?

    Where are the models of ice sheet disintegration that contain the physics of ice streams, effects of surface melt descending through crevasses and lubricating basal flow, or realistic interactions with the ocean?

    Where are the models predicting the sizes of mini-Meltwater pulses that may be expected through the next few decades as the WA and Greenland ice sheets begin to disintegrate?

    It is only when such models do become available that more realistic assessments of the potential impacts on other systems (eg industrial dynamics, economic circuitry, life-support systems) can be made.

    On the matter of ice sheet disintegration and huge sea level rises, Freeman Dyson should reconsider his position. The world is not overly relying on models. There is plenty that is being observed and plenty to be observed, but there is a dirth of models on matters which are of critical importance that may give us better insight into the unnecessary emergencies we are allowing to happen.

    Comment by Michael — 13 Aug 2007 @ 4:23 AM

  89. Re #78:

    Yes, but not sure why you would say that the MODIS images differ significantly from Cryosphere Today. Here is the MODIS Aqua of the Northwest Passage on Saturday, with the direct McClure Strait route all but open for perhaps the first time in recorded history:
    http://rapidfire.sci.gsfc.nasa.gov/realtime/single.php?2007223/crefl2_721.A2007223184001-2007223184500.2km.jpg

    Roald Amundsen could have motored through in under 10 days. (He actually took 3 years, and a much less direct route).

    Comment by Glen Fergus — 13 Aug 2007 @ 4:43 AM

  90. How is the record low sea ice impacting greenland? Someone knowing current developments in ice quake frequency or outlet flows?

    BTW the lack of media coverage of this current event baffles me… It should be front pages news!

    Comment by horrified observer — 13 Aug 2007 @ 5:51 AM

  91. Re 59. Thank you for the link. From page 93 of that document: “A complete collapse of the Greenland Ice Sheet, projected to take roughly 1,000 years once local warming reaches about 3°C (which is expected by late this century), would increase global mean sea level by about 7 m. The collapse of the West Antarctic Ice Sheet (WAIS), which would likely take a comparable amount of time, would add another 4 to 6 m. While the IPCC’s 2001 estimates do not anticipate significant loss of ice mass from either ice sheet during the 21st century, accelerated retreat of some ice streams has recently begun in Greenland, and some parts of the WAIS also seem to be nearing destabilization (Vaughan and Spouge, 2002; Schiermeier, 2004; Dowdeswell, 2006.)”

    I am not sure that addresses the matter of a clear reference point of the liklihood of a sea level rise of several metres by 2100 for business-as-usual.

    There is a state of confusion amongst risk managers.

    There needs to be a Delphi study in which the top 100-500 climate scientists input their estimate of what they expect the sea level rise to be by 2100 if we carry on business-as-usual. Delphi studies which accumulate the experts’ opinions / estimates into one summary histogram are standard practice for futures studies in science, technology, engineering, etc. There doesn’t have to be named attribution to each data point.

    The world needs a reference point that says … this is the expectation profile of a very large number of the world’s climate scientists of sea level rise through the next 9 decades.

    Once the world has that reference point, others can then do their jobs with the world’s best estimate. The IPCC SLR numbers were not that. There is too much at stake for climate scientists to allow risk managers in corporations and elsewhere to continue assuming that the IPCC SLR estimates of a few centimetres are the ones that should be used.

    The world needs its best estimate. The matter is urgent.

    Comment by Michael — 13 Aug 2007 @ 6:33 AM

  92. I’ve looked at the MODIS satellite images a little closer (and with some places having less cloud cover.)

    There still isn’t a way through the NorthWest Passage without an icebreaker. Maybe in another week or two.

    But that is just the problem with the Passage. There is only a few weeks from mid-late-August to mid-September when the Passage is open for non-ice-breaking ships. In some years, there is no opening at all.

    As well, there are two or three distinct paths to take. In any one year, only Path3 is open while 1 and 2 are closed off. It would make no sense to station a ship off Baffin Island in early August wating for the satellites to tell you which one of 3 Paths is open for the next few weeks.

    In addition, the winds can quickly close off any opening so the risk-return trade-off is just not there (unless global warming extends the Opening to two or three months, rather than a few weeks.)

    Comment by John Wegner — 13 Aug 2007 @ 9:23 AM

  93. Re #83:

    J.S., there is a lot of sea ice in the Antarctic winter, which makes it very difficult to impossible to reach any coastal station. See: http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/current.area.south.jpg
    Summer sea ice is around 2 million km2, winter around 15 million km2.
    The overall trend seems to be slightly positive, between 0.5-1 million km2.
    Re #86

    Petro, indeed, there is a winter shrinking, with the past few years some extra. But since 1970, the winter trend is about -0.5 million km2 over 35+ years, while the summer trend is about -2 million km2 in the same period. That means that summer-winter refreezing increased with about 1.5 million km2. Which is remarkable, as one may expect that winter and summer decrease would be similar.

    Re #90

    Up to 2004, the retreat of the largest Greenland glacier (near Ilullisat) can be seen at Wiki, but one need to compare the period 1953-2003/4 to the previous period of strong retreat of the breakup point (1929-1953) at the same page. Moreover, the summer (melt) temperatures around Greenland don’t/hardly reach the 1930-1945 temperatures.

    Comment by Ferdinand Engelbeen — 13 Aug 2007 @ 9:47 AM

  94. re 93:

    “…there is a lot of sea ice in the Antarctic winter, which makes it very difficult to impossible to reach any coastal station…”

    Yes, I understand this about winter conditions; it’s rather common knowledge. For McMurdo Station, if I recall orientation correctly, this affects flights from New Zealand and other (relatively) nearby points, as well. It is not unusual for planes to be turned back mid-flight due to changing weather. Which is why the coastal stations have intermitant arrivals, and the interior stations, like the South Pole station, are completely cut off during Antarctic winter.

    Of course, my original question regarded sea ice extent in February, which is Antarctic summer.

    The link you provided was originally posted by Petro in 63, where I first saw it. But thank you all the same.

    Comment by J.S. McIntyre — 13 Aug 2007 @ 10:14 AM

  95. Timothy Chase (#67) said: It should be obvious how bad things are to anyone reading the headlines who has a wit of common sense – given the power struggle that is beginning to be waged by Russia, Canada, US, Sweden and the Netherlands over the Arctic Ocean oil reserves. Fighting over oil under these circumstances! Someone must have a perverse sense of humor.

    I know this is off topic, but I think that the powers-that-be are probably even more afraid of peak oil than they are of global warming…..

    Comment by john mann — 13 Aug 2007 @ 10:32 AM

  96. re 94, 93 et al

    Answered my question re Sea Ice in February.
    It’s a pretty informative, interactive link:

    http://nsidc.org/data/atlas/

    Just click on your favorite hemisphere. It doesn’t address record amounts, though I will note everything I looked at regarding SHELF ice and glaciers point to a decline, not an increase.

    Comment by J.S. McIntyre — 13 Aug 2007 @ 2:00 PM

  97. Re #93: “That means that summer-winter refreezing increased with about 1.5 million km2. Which is remarkable, as one may expect that winter and summer decrease would be similar.”

    And after the summer ice goes completely, the difference will be even larger! The key point is that what refreezes is quite thin, and thus is prone to quick melting the next year. Ironically the refreezing allows the retention of much of the heat gained by open water during the summer.

    Regarding Greenland temps, this paper discussing trends for the entire Arctic is useful. From the conclusions:

    “In the Arctic in the mid-1990s an abrupt rise in SAT was noted (by about 18C in comparison with the 1951–90
    mean); this then stabilized and has remained at this level up to now. The greatest warming occurred in autumn and spring, and the lowest in summer and winter. In the period 1995–2005, the warming was greatest in the
    Pacific (by 1.458C) and Canadian (by 1.268C) regions,
    and lowest in the Siberian region (by 0.828C).”

    That said, the exact pattern of warming is not the same as predicted by the models, and there is no published detection and attribution study for the Arctic.

    Another thing to bear in mind about Greenland is that inferring temperatures up on the ice sheet from the surface stations around the edges has its limitations.

    Comment by Steve Bloom — 13 Aug 2007 @ 2:12 PM

  98. 1978 and 1979 were the coldest years in the US since 1929. There was a general cooling trend in the US since the Dust Bowl days of the mid 1930′s down to 1979. I remember some climatologists back in the late 1970′s predicting that the Earth was heading for the next Ice Age. Strange that you would use 1979 as your comparison photo. It would be nice to have one from the mid 1930′s or mid 1950′s when it was just as hot as it is now but there were no satellites to take the pictures back then.

    By the way everyone is missing the point. The Earth is warming. It has been warming since the last Ice Age and will continue to warm until the break over point to the next Ice Age is reached no matter what Humanity does. We only have the choice to get to the break over point earlier or later by the actions that we take.

    Comment by Curtis Metz — 13 Aug 2007 @ 3:57 PM

  99. Re #67 [given the power struggle that is beginning to be waged by Russia, Canada, US, Sweden and the Netherlands over the Arctic Ocean oil reserves.]

    I’ve not heard that Sweden or the Netherlands have any territorial claims in the Arctic. Norway and Denmark (which has sovereignty over Greenland) do. There’s a map here:
    http://news.bbc.co.uk/2/hi/americas/6941426.stm

    Comment by Nick Gotts — 13 Aug 2007 @ 4:16 PM

  100. Re #93: “That means that summer-winter refreezing increased with about 1.5 million km2. Which is remarkable, as one may expect that winter and summer decrease would be similar.”

    If one was to think that the winter and summer decrease would be similar then they would not be facing up to reality.

    The winter ice grows out from the perennial ice cap due to the cold air forming over the ice and freezing the water at the ice edge. This growth can continue until the surrounding water is at a low enough latitude that the water is too warm to freeze. Since ocean sea surface temperatures change little on an annual basis the maximum ice edge does no vary either. On the other hand, the minimum ice edge is determined by the thickness of the ice. As the perennial ice thins then since the sun can melt a fixed thickness, a larger area will be completely melted and expose the ocean beneath.

    If the sea ice system was linear, then winter and summer decrease would be similar, but there are positive and negative feedbacks. The positive feedbacks dominate the melting and that will lead to a sudden collapse of the ice.

    Not only will the sea ice disappear suddenly, but with its demise the main air conditioning unit for the Northern Hemisphere will be gone. This will lead to an abrupt warming with temperatures in Greenland rising by 20C within three years, just as they did 10,000 years ago at the start of the Holocene.

    Timothy Chase (#67) said: It should be obvious how bad things are to anyone reading the headlines who has a wit of common sense – given the power struggle that is beginning to be waged by Russia, Canada, US, Sweden and the Netherlands over the Arctic Ocean oil reserves.

    That fight over oil reserves will be nothing compared to the wars that will ensue when the starving Chinese, Indians, and Africans invade North America, Russia, and Europe in search for food!

    Comment by Alastair McDonald — 13 Aug 2007 @ 4:30 PM

  101. Remember the Arctic circle has 6 months of darkness starting on September 21-22. It gets very cold in the Winter at the North Pole.

    The average annual temperature at the North Pole is -24.5C (South Pole is -49.5C) ICE causing temperatures to say the least.

    Comment by John Lang — 13 Aug 2007 @ 5:01 PM

  102. Re #101 But it can only get down to -24.5C because the water is covered with ice! If there was only open water then the surface could not cool below -2 C. You need a solid surface nearby to provide the cold air so that deep water can freeze!

    Comment by Alastair McDonald — 13 Aug 2007 @ 5:44 PM

  103. I simply don’t have time to read all of these entries right now, but I will later.

    I think I have said here, a few times at least, that this was going to happen. I have been watching it very closely over the last year (daily thanks to the university of Bremen http://iup.physik.uni-bremen.de:8084/amsr/amsre.html) and the areas which showed the most warming over the winter months were pretty much the first to disappear during the summer.

    Also I watch all the cyrosphere news on a daily basis. The most interesting news to me this year was the 10m multi year ice which locked in the fishing fleet earlier this year. The icebreakers were unable to get in to reach them, yet icebreakers can sail to the pole with regularity today. That means the pole is still flushing out the thick multi year ice and replacing with new thinner ice. More melt, faster.

    It is always the summer ice lows which get the news, but it is the winter ice melt and lows which are much more dramatic, if in a smaller way, because they are the proof of much more dramatic change.

    Also after 3 winters in Sweden, spaced out over 7 years, I am personally seeing a trend. There is more cloud in the winter. As a result, temperatures are up to 10degC higher in the winter now. As a result of which the sea is not freezing as much, which means more heat from the water, etc, and the great circle goes on.

    Reports from Tara Arctic this winter were of very cloudy skies, lots of snow and, except for very severe events, much warmer temperatures than normal.

    Also a very interesting point is that the sea under the Ice cap is -1.7 degC. It is Fresh water which is freezing to -24 degC in the arctic, Sea water does not freeze until you reach -7… Remove the fresh water Ice, add clouds and you remove the ability of the pole to freeze in the winter. Then you have a Serious tipping point.

    I always find that statements like “The great oceanic conveyor stopping completely will cause another ice age” as interesting. My logic goes like this.

    The climate warms
    which warms the Arctic
    Which slows the conveyor
    Which does?
    Very little because the Arctic cannot provide the same level of cooling because it, itself, is warming. Otherwise, it would have been impossible at any time for the Arctic to have had a climate close to that of Florida. But we know for a fact that it did.

    It is like the argument that txt messaging on mobile phones will cause longer thumbs in 5,000 years. Actually not, we will all be walking around with sugar powered chips in our body in 100 years time and won’t use our thumbs for any form of messaging, just our brains. Perhaps we’ll get smarter as we use our brains more????

    Comment by NeilT — 14 Aug 2007 @ 4:28 AM

  104. RE # [That fight over oil reserves will be nothing compared to the wars that will ensue when the starving Chinese, Indians, and Africans invade North America, Russia, and Europe in search for food!]

    Untrained people, let alone starving ones, do not form armies capable of invading functioning modern states. In fact, I cannot recall offhand any recorded instance of an army of the starving invading anywhere, anytime – although invading armies may starve after invading, due to “scorched earth” defence, bad weather, and/or logistic failures. Large-scale starvation in China, India or Africa may lead to state collapse, increased levels of attempted unauthorised immigration to North America and Europe, and possible wars of distraction launched against traditional and/or weak enemies by elites desperate to rally their populations, but nonsense of the sort quoted above will merely encourage racism and militarism in North America and Europe.

    Comment by Nick Gotts — 14 Aug 2007 @ 5:09 AM

  105. Re: 98 (Curtis Metz)

    What are you talking about?

    The warming following the last ice age peaked around 6000 years ago, followed by a very slow temperature fall:

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

    And US temperatures are NOT global temperatures, or even arctic temperatures..

    Re: 100, 102 (Alistair)

    20K warming in Greenland in 3 years? Certainly the removal of permanant arctic ice would be bad, but I wasn’t aware of any research that said it was *that* bad..

    Comment by Andrew Dodds — 14 Aug 2007 @ 6:01 AM

  106. re: 98. “I remember some climatologists back in the late 1970’s predicting that the Earth was heading for the next Ice Age.”

    You may want to read about that myth at http://www.realclimate.org/index.php/archives/2005/01/the-global-cooling-myth/

    Comment by Dan — 14 Aug 2007 @ 6:27 AM

  107. [[By the way everyone is missing the point. The Earth is warming. It has been warming since the last Ice Age and will continue to warm until the break over point to the next Ice Age is reached no matter what Humanity does. We only have the choice to get to the break over point earlier or later by the actions that we take.]]

    Curtis — The world has NOT been warming “since the last ice age.” If you calculate the effects from the assorted Milankovic cycles (it involves a lot of matrix math), you find that we passed the peak of the interglacial 6,000 years ago and the world should now be COOLING. The present warming is not natural. “We’re just coming out of an ice age” doesn’t correspond to reality.

    Comment by Barton Paul Levenson — 14 Aug 2007 @ 7:09 AM

  108. re 104

    “Large-scale starvation in China, India or Africa may lead to state collapse, increased levels of attempted unauthorised immigration to North America and Europe, and possible wars of distraction launched against traditional and/or weak enemies by elites desperate to rally their populations, but nonsense of the sort quoted above will merely encourage racism and militarism in North America and Europe.”

    Agreed … to a point. As someone once said, no country is more than a couple of meals from revolution. And from revolution is born chaos.

    This is a new age, a nuclear age, and that changes the equation dramatically. Put another way, the worst type of enemy is one that is convinced they’ve nothing to lose.

    Comment by J.S. McIntyre — 14 Aug 2007 @ 9:32 AM

  109. Re #108 [As someone once said, no country is more than a couple of meals from revolution. And from revolution is born chaos.]

    Well, “someone” was wrong! Food shortages may cause riots, but revolution requires a loss of the ruling elite’s control over a significant segment of its armed forces (and while there’s any available food at all, the armed forces and their dependants will be first in line), or the successful formation of rival forces in an area uncontrolled or very poorly controlled by the ruling elite.

    [This is a new age, a nuclear age, and that changes the equation dramatically. Put another way, the worst type of enemy is one that is convinced they’ve nothing to lose.]

    Agreed – but the enemy we have to fear is a ruling elite on the edge of losing control, not a starving horde. Even then, such an elite is much more likely to attack a neighbour perceived as weaker than a core power – but there are cases where this could lead to a nuclear war big enough to cause global breakdown.

    Comment by Nick Gotts — 14 Aug 2007 @ 11:42 AM

  110. I note the NSIDC Arctic Ice News Page http://nsidc.org/news/press/2007_seaiceminimum/20070810_index.html
    Particularly figure 5 http://nsidc.org/news/press/2007_seaiceminimum/images/20070814_rate.jpg (and comments).
    It seems that this unusually early melt is due to specific conditions: “Taken together, the rapid sea ice losses that we’ve seen in June and July can partly be explained from the effects of this “triple whammy”: it was warm; atmospheric circulation pushed ice away from the coast; and skies have been fairly clear.” (and yes; I have noted the paragraph that follows the above quote)

    So before people start incorporating this into considerations of long term melt trend, future years might not quite reach it for a bit. i.e. don’t go expecting this to happen next year. The trend is still worrying enough without possibly unwise extrapolation from one years data.

    What particularly interests me with regards the Arctic ice-melt is the effect on Northern Hemisphere climates by impact on jet stream tracks. Obviously there’d be a further impact on permafrost and glacier melt, but this warming with regards sea level rise is a longer term issue. So as with the vagueries of Arctic geo-politics it’s something we’ll find out as we go.

    I’m less and less convinced about the utility of equating changes in the Thermohaline Circulation with events such as the Younger Dryas and coming up with “freezes”. Changes in atmosphere and ocean circulation implied seem to me to be far more important for us, due to food impacts. We’ve had odd summer weather this year in the UK (as far as I can see, largely down to the El Nino), a summer that just goes to show how a change in Pole/Equator weather systems can have substantial impacts.

    Thanks to William Chapman and all at Cryosphere Today (an all year regular site for me) and Mark Serreze and all at NSIDC for their seasonal roundups. Greatly appreciated by this British amateur climate science enthusiast. :)

    Comment by CobblyWorlds — 14 Aug 2007 @ 3:37 PM

  111. #102, Alastair must have lived in the Arctic, that is correct, the coldest place for ice is just North of Ellesmere and Northwest Greenland in February when a local High spreads Northwards often generating -50 C conditions at sea level, this creates multy year ice. The open Arctic ocean sea water scenario during winter is a little more complex, the biggest component has something to do with winds, which actually keep Polyneas open at -40 C. Clouds come next, so with say -24.5 C conditions, you can have open water provided it is always windy, or very cloudy with a little less wind. Weather underground Dr Masters, called it right when he said that further South winter will be delayed as well, but the biggest thing is the dynamics now of a cold and warmer zone at the Pole, surely affecting current weather everywhere in the Northern henmisphere. Not so long ago the Pole had a more even distribution of ice and that was the summer/fall weather we were use to.

    Comment by wayne davidson — 14 Aug 2007 @ 8:13 PM

  112. I have noticed that each year the main variability and recent ice decline has been in the shallower part of the Arctic Basin. The deepest part of the basin seems to keep its ice coverage each year. I wonder if the recent minimums are the lowest that the ice extent can get given the present state of the arctic climate and it won’t get any worse unless there is more significant arctic warming. One other item of interest is that the reanalysis data from NCEP shows that much of the region of the arctic basin where there is open water was slightly BELOW average in temperature from June through August10th in the height of the melt season. Could it be the warmer waters of the north atlantic ocean(warm phase AMO) that are flowing up into the arctic basin part of the reason for the shallow water melt-off in recent years? The decline really kicks in after the mid 1990s when the AMO flipped to the warm phase. From the late 70s to mid 90s, there was some small decline but the AMO was in the cold phase much of this time and slowly phasing back to the warmer phase. Could this decline be
    relayed to the AMO phase at least partly??

    Comment by Dave Nicosia — 14 Aug 2007 @ 8:22 PM

  113. Re 53
    The Salinas River is dead. That mud in the lettuce farmer’s fields is made with water from Sierra snow melt.

    Re 81, 82
    My point was that as much as 80 meters of relatively fresh water floats on the surface of the Arctic, and on which, most of the sea ice floats. This layer of fresh water has a dramatic effect on the formation of Arctic sea ice. Fresh water freezes at higher temperature than sea water.

    Frozen bulk sea water sinks. The ice that forms on the surface of the ocean is crystals of fresh water ice that exclude most of the impurities as they freeze. It must be significantly colder for ice crystals to form from sea water than from fresh water. This fresh water ice floats. The impurities rejected from the crystals form cold brine that sinks.

    If, and when, the fresh water ice melts, it often leaves a layer of low salinity water which may protect other sea ice from the warmer, saltier water that is below the surface in the Arctic. Thus, sea ice protects the surface layer of fresh water from storm mixing, and, the layer of fresh water protects the sea ice from the warmer saltier water below.

    Lose the Arctic sea ice, and storms mix the surface fresh water into the warmer, saltier mid-waters making the reformation of sea ice much more difficult. This is in addition to the loss of albedo as the ice melts.

    Comment by Aaron Lewis — 14 Aug 2007 @ 9:27 PM

  114. Curtis Metz, do you mind my asking, where do you get your beliefs? I’m always curious what sources people have relied on for what they believe to be true, when they come here and post those beliefs.

    I went looking for what you posted and found the same thing a few places, but nowhere that looks like a primary source, just people stating the same belief:
    http://www.google.com/search?num=100&hl=en&newwindow=1&safe=off&client=firefox-a&rls=org.mozilla%3Aen-US%3Aofficial&hs=lCB&q=%22been+warming+since+the+last+Ice+Age%22+%22will+continue+to+warm%22+&btnG=Search

    If these aren’t you, or even if they are, can you say a bit about your source, who you trusted for what you believe? What source you relied on?

    Comment by Hank Roberts — 15 Aug 2007 @ 12:28 AM

  115. Barton Paul Levenson (#107) wrote:

    Curtis — The world has NOT been warming “since the last ice age.” If you calculate the effects from the assorted Milankovic cycles (it involves a lot of matrix math), you find that we passed the peak of the interglacial 6,000 years ago and the world should now be COOLING. The present warming is not natural. “We’re just coming out of an ice age” doesn’t correspond to reality.

    Solar forcing has been diminishing at least since 1960 and as such, we are experiencing solar cooling. The only problem is that the temperature is still going up.

    When it is said that solar variability may have been the dominant forcing in the early twentieth century, our best estimates are that this is true only if you break up the forcing of the greenhouse gases, e.g., carbon dioxide or methane. Relative to a base year of 1880, it would appear that the forcing due to anthropogenic greenhouse gases have had a greater forcing than that of solar variability – continuously – since 1880.

    Comment by Timothy Chase — 15 Aug 2007 @ 12:46 AM

  116. Re 113
    Is this bit of physics in either the ice model or the ocean model or did this interface between ice and ocean get left out?

    Comment by Aaron Lewis — 15 Aug 2007 @ 12:52 AM

  117. An interesting forum.My question is why are the temperatures last year , but even more dramatically this year , so high in the area of the Canadian Archipelago? I have noticed that this summer of 2007 they are consistently 4 – 6C higher than the norms , eg Resolute and even Alert.

    Comment by John Locke — 15 Aug 2007 @ 10:56 AM

  118. Re: #72 hoosiernorm:

    You’re looking at the seasonal cycle of the total extent. There is strong seasonal variability, so the interannual change during specific time of year isn’t easy to see in the images you’re referring to. That’s why anomaly images are produced.

    walt

    Comment by Walt Meier — 15 Aug 2007 @ 12:18 PM

  119. #117, Mainly because the Earth is warmer, more energy in its system, and that it takes time for the excess heat to escape to space, especially when its replaced by a continuous cause for more heat (greenhouse gases. including especially new sources of water vapour a powerful feedback). Monthly warming anomalies in the Canadian Archipelago went almost continuously, with a few breaks for several recent years. I have observed not only extensive clouds (during long lasting Polar “heat waves” ), but also warmer temperatures during clear dark skies which are quite amazing. A warmer heat threshold has been surpassed and maintained which means that the entire Polar region is changing along with it.

    Comment by wayne davidson — 15 Aug 2007 @ 12:36 PM

  120. Re #117 I suspect the main reason why the summer temperature around the ARctic are much higher is that there is more water vapour which is the main greenhouse gas. Water vapour produces a positive feedback because it causes warming and warming means more water vapour. Provided clouds do not form, then then water vapour can cause a runaway warming. While there is ice on the ground, there is very little water vapour in the air. However once the ice/permafrost has melted the ground can get very warm, and so does the air and water vapour. Sea ice melting will have a similar effect, but the sea surface cannot warm as much as the land.

    Comment by Alastair McDonald — 15 Aug 2007 @ 4:50 PM

  121. Re #97: I just noticed that I quoted a figure of 18C for early 20th century Arctic temperature rise. That was a typo from the paper; obviously it should be 1.8C. Hopefully that didn’t give anyone the wrong idea.

    Re #s 100/5: Big temperature rises in NH high latitudes are known to accompany the end of ice ages. Even if the 20C number Alastair quoted is high (I haven’t checked), and given that the worst we could expect now would be a smaller number than the ice age terminations since we’re starting off with higher temps and lower ice mass, bear in mind that even a few degrees additional warming in Greenland would seal the fate of the ice sheet. Then it would just be a question of how fast the melt/collapse will come. Of course this is the big fear being expressed by Hansen just now.

    Re #118: Thanks for sticking with the thread, Walt!

    Comment by Steve Bloom — 16 Aug 2007 @ 1:03 AM

  122. http://members.optusnet.com.au/anon10/NWP13-8-2007.jpg

    Comment by Glen Fergus — 16 Aug 2007 @ 2:54 AM

  123. I thank those who have attempted an explanation for the consistently high temperatures in such places as Resolute , Alert and I might add Eureka ( the last mentioned environmental Canada explained was due to bare rock and an inland location)Personally I suspect unusual wind circulation patterns.But even with northeasterlies lately produced temperatures still consistently 4C above what you would expect .I am not a physicist so plain common sense explanations please.I use ” Arctic Theme Page ” for my data.
    I have incidentally noticed some discrepancy between ice coverage given by “Cryosphere today ” and “Environmental Canada ice coverage with explanation ”

    ta

    Comment by John Locke — 16 Aug 2007 @ 3:40 AM

  124. Re:112

    So why is the current years melt (unprecedented or not), reaching right into the heart of the deep arctic basin?

    Watching the daily IR maps for the last 6 months has been very revealing in terms of melt freeze patterns.

    I suppose time will tell as the sea gains more and more heat each year, whether or not the main central cap will melt. But it doesn’t look good.

    My feeling is that the 2006 cooling was unprecedented and 2007 is more representative of the general trend.

    Generally I wonder why, once science has defined events such as tipping points, science tries to deny cumulative events and tipping and tries to pass them off as aberations??

    Comment by NeilT — 16 Aug 2007 @ 4:12 AM

  125. 91 – I don’t think you can create a useful view of the risk by asking for the best-guess estimates from a large number of scientists in this case. The simple, plain fact is that we simply don’t know how quickly Greenland will melt so this necessarily introduces a large amount of uncertainty.

    The best course of action to take is simply to restrict emissions so that the warming is not sufficient to melt Greenland. This will be easier to achieve the earlier we start seriously to attempt to do so. We have wasted enough time already and there remains considerable uncertainty about how much time we have left (it might not be much).

    Comment by Timothy — 16 Aug 2007 @ 10:49 AM

  126. Even the NSIDC is within 40,000 Km of the minimun as of August 13, which is about 1 or 2 days melt at this time of year, so I imagine the NSIDC will announce the official mimimun in their weekly update.

    I find that Environment Canada 50% ice coverage chart is always out to lunch for the far north. I find that huge sections of ice suddenly disappear overnight, suggesting that they don’t update for weeks at a time.

    Also I have not seen anything on the North Pole webcam camera 3 or 4 deployment, and the Polarstern is now heading south again after getting to 85 north. The last photos showed the ice to broken up to deploy the new cameras at 85 north. Does anybody know if they aborted that mission for the two new north pole web cams?

    Comment by Larry — 16 Aug 2007 @ 11:07 AM

  127. Timothy (the other Timothy) stated in #125:

    91 – I don’t think you can create a useful view of the risk by asking for the best-guess estimates from a large number of scientists in this case. The simple, plain fact is that we simply don’t know how quickly Greenland will melt so this necessarily introduces a large amount of uncertainty.

    There are a few things we do know and rather well.

    First, the arctic will be free of sea ice during the summers – and sooner rather than later. Second, a rise in temperatures in the northern hemisphere is usually accompanied by a drop in temperatures in the southern hemisphere. Third, ice loss in Greenland has been (for lack of a better word) accelerating during the past years with ice quakes increasing in frequency and intensity. The same is happening in the Western Antarctic Peninsula with over a hundred glaciers picking up speed as they head towards the coast. Fourth, both Greenland and Antarctica are experience net mass loss. Fifth, rising water will raise glaciers which are partly emersed by ocean.

    Positive feedback. Between Greenland and the Western Antarctic Peninsula. Things could start moving very, very quickly. And it would seem they already are with regard to the arctic sea ice. A lower albedo in the arctic due to the loss of sea ice is a large part of what is raising the temperatures in Greenland. More sunlight being absorbed.

    This certainly isn’t a time to panic.

    Never is. But I believe it is time to start acting more wisely.

    PS

    Nice to meet my namesake.

    Comment by Timothy Chase — 16 Aug 2007 @ 12:03 PM

  128. Re #127: I think that second peninsula reference should be to the West Antarctic Ice Sheet.

    Comment by Steve Bloom — 16 Aug 2007 @ 7:02 PM

  129. North Pole Webcam from August 11 2007:

    http://www.arctic.noaa.gov/latest/noaa4.jpg

    North Pole webcam from August 11, 2006

    http://www.arctic.noaa.gov/npole/2006/images/noaa1-2006-0811-1445.jpg

    North Pole Webcam from August 11, 2005

    http://www.arctic.noaa.gov/npole/2005/images/noaa9-2005-0811-2259.jpg

    North pole Webcam from August 11, 2004

    http://www.arctic.noaa.gov/npole/2004/images/noaa1-2004-0811-1455.jpg

    From August 11, 2003

    http://www.arctic.noaa.gov/npole/2003/images/noaa1-2003-0811-2208.jpg

    August 11, 2002

    http://www.arctic.noaa.gov/npole/2002/images/noaa-2002-0811-1750.jpg

    Comment by John Wegner — 16 Aug 2007 @ 7:19 PM

  130. Anyone bother to look at http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/sea.ice.anomaly.timeseries.jpg as a step function graph rather than thinking either in terms of long-term average trends or very short-run events? Last time the area anomaly was positive was in early 2003, but running back as far as 1997 the usual anomaly was about 1/2 million — with only brief excursions far from that range. Starting in early 2005 it took a step down to about a million. Given how long its been at nearly 2 million now compared to the generally brief diversions usually seen, it seems likely that another step down has happened — although it would be too soon to project a usual value for the anomaly (the transition may not be complete).

    Comment by Sphere — 16 Aug 2007 @ 9:30 PM

  131. Each year the Arctic sea ice meltback appears more dramatic and prompts the obvious discussions on causes.

    Comment by seo yaismasi — 16 Aug 2007 @ 11:57 PM

  132. I live in southern Finland which is still quite far from north pole, 2000 miles or something. But I have noticed that the winter here corresponds quite well the ice coverage in arctic sea. Last time we had a cold winter here was 2002/2003. It was the last time when you could safely drive with car on top of the sea ice. And that was also the last time when arctic ice anomaly was positive.

    Last winter here was very short. We only had sea ice one month. That was February. Both December and January were warmest in the recorded history.

    Comment by Matti Meikäläinen — 17 Aug 2007 @ 2:10 AM

  133. Its now official. The more conservative NSIDC has now indicated that we have broke an all time minimun ice extent as of August 16.

    So we now have new records, for area as of August 9 and extent for Aug 16 from NSIDC. And we have at least another month to go.

    Link

    Comment by Larry — 17 Aug 2007 @ 10:51 AM

  134. Reply to 133: Well, that should sum it up well. We can expect to hear the nay-sayers attribute this to a “unusual cloud free melting season allowing more of the suns engergy to make it the lowest it’s ever been recorded. And many people will buy it as the “supporters” as I call them try to “nail” the science down and then argue with someone who knows much more about Atmospheric Science and AGW theories then themselves. Then they get mad when you correct them, destroying their “theory”.

    My personal favorite is when naysayers confuse the Artic and the Antartic with each other, claiming the “south pole is all ice, no land. You think Antartica is a continent because its such a huge piece of ice? It’s entertaining but severly fustrating at the same time. I also had to argue why AGW doesn’t tend to “increase” the ammount of hurricanes, just their intensity.

    Comment by Chris S — 17 Aug 2007 @ 6:22 PM

  135. Reply to 134. Well now you’ve got the other end to contend with. Recently someone from Greenpeace tried to involve me in “global warming”. My reaction, and response, was: Too late.

    We can jawbone all we want to, but the storyline is set — and there’s not a whole lot we’ll be able to do about it. Not saying that I really know what’s coming down the pike, but it’s too late to make any sort of societal change that will have a real effect. (My best guess is that I’ve got valuable ocean-front property in about two decades — currently at about 100 feet overlooking Boston.)

    Comment by Sphere — 17 Aug 2007 @ 8:00 PM

  136. Hey, greed and selfishness are forms of spiritual poverty, and will always be with us.
    “Too late” is just another excuse not to learn enough about the science to realize you may very well be wrong.

    That’s what science is for.

    Comment by Hank Roberts — 17 Aug 2007 @ 8:35 PM

  137. Reply to 136. I see you don’t get it.

    Comment by Sphere — 17 Aug 2007 @ 9:16 PM

  138. I got it —- a 10-year window of opportunity to take decisive action. Lucky me it happens when I’m available to help.
    James Hansen et al, 2007. Climate Change and Trace Gases. Philiosophical Transactions of the Royal Society – A. Vol 365, pp 1925-1954. doi: 10.1098/rsta.2007.2052. http://pubs.giss.nasa.gov/docs/2007/2007_Hansen_etal_2.pdf

    Comment by Hank Roberts — 17 Aug 2007 @ 9:34 PM

  139. Chris S. wrote: “My personal favorite is when naysayers confuse the Artic and the Antartic with each other, claiming the “south pole is all ice, no land. You think Antartica is a continent because its such a huge piece of ice? ”

    It sounds like you must be arguing with 3rd graders to find naysayers who confuse the Arctic and Antarctic in such a way.

    Perhaps you can instruct the slightly more educated naysayers like myself. I do not questions the extent of melting Arctic ice. I do question why the cause would be pinned on CO2- a well mixed greenhouse gas that should warm both poles somewhat equally.

    Why is the sea ice in the Antarctic not melting?

    Why has Antarctica not warmed or even cooled in the last 20 years when we are at near record global temperatures?

    And why was the Antarctic peninsula warming from 1940 to 1970 when the atmospheric temeratures were globally cooling?

    And why with all the melting in the Arctic, has sea level dropped over the past 20 years?

    Perhaps these are more sophisticated questions than you are prepared to answer? But the CO2 connection does not readily explain any of these differences to a naysayer [edit]

    Comment by Jim Steele — 17 Aug 2007 @ 11:01 PM

  140. All of the AR4 models were already getting ice extent wrong, yet still fit the historical data, so the models have other errors that compensate for missing this increased melting climate behavior. The models may well go wild in their projections while the climate continues its rather unalarming pace.

    Comment by Martin Lewitt — 18 Aug 2007 @ 2:50 AM

  141. Re #138 where Hank wrote ‘I got it —- a 10-year window of opportunity to take decisive action.’

    Sorry Hank, but you are wrong. There is no 10 year window of opportunity. That may have existed when the Kyoto treaty was negotiated ten years ago, but it has gone now.

    In the paper you cite, Hansen et al. wrote:

    Palaeoclimate data show that the Earth’s climate is remarkably sensitive to global forcings. Positive feedbacks predominate. This allows the entire planet to be whipsawed between climate states. One feedback, the ‘albedo flip’ property of ice/water, provides a powerful trigger mechanism. A climate forcing that ‘flips’ the albedo of a sufficient portion of an ice sheet can spark a cataclysm. Inertia of ice sheet and ocean provides only moderate delay to ice sheet disintegration and a burst of added global warming. Recent greenhouse gas (GHG) emissions place the Earth perilously close to dramatic climate change that could run out of our control, with great dangers for humans and other creatures.

    Where he wrote “Inertia of ice sheet and ocean provides only moderate delay to ice sheet disintegration” I think he was referring to the Greenland and Antarctic ice sheets. The Arctic sea ice sheet does not have that inertia, and with its demise there will be a major release of the main greenhouse gas – water vapour. Hansen’s cataclysm is only about ten months away, not years.

    You can see that with the recent melts the recovery of the winter ice has begun later in the year. After this record melt the regrowrh will start later yet and the near total recovery we have seen in the past will not be possible this winter due to lack of time. Next summer the smaller ice pack will melt even faster and alsmost certainly disappear altogether.

    We have already seen this year that the areas of the world with Mediterranean type climates are suffering record temperatures which cause destructive wild fires. They reached the outskirts of Athens this week. With no Arctic sea ice these regions will become deserts within a year, and the disrption to world agriculture will result in global famine.

    Think about it :-(

    Comment by Alastair McDonald — 18 Aug 2007 @ 5:28 AM

  142. I do question why the cause would be pinned on CO2- a well mixed greenhouse gas that should warm both poles somewhat equally.

    Why should it warm both poles somewhat equally?

    Comment by dhogaza — 18 Aug 2007 @ 8:16 AM

  143. Reply to post 139:

    Well, yes they are far more sophisticated for me to answer considering I am a 23 year old who changed majors from teaching Earth Science, to doing something a bit more challenging and getting a M.S. in atmospheric science, which I’d later in life would like to each those same classes I’d be taking. I speak of “Naysayers” I’m not talking about Atmospheric Scientists and Climatologists like your selves. I’m talking about 30 – 50 year old men and women who confuse the artic ice cap and anatartica. You can’t pass 3thd grade if you don’t know the difference. Sad but true. It could be the cause of why so many people are swindeled.

    But as someone who has always thought “Scientifically” and “theorized” everything I’ve ever read on any science matter, I often wonder about alot of things that are said not only here, but everywhere about Climate.

    But I’ll give it a shot…

    Perhaps you can instruct the slightly more educated naysayers like myself. I do not questions the extent of melting Arctic ice. I do question why the cause would be pinned on CO2- a well mixed greenhouse gas that should warm both poles somewhat equally.

    Isn’t there a large carbon sink in the southern hemisphere that was recently studied and deemed “completely saturated of Co2″? Maybe that’s the reason. I’m still studying Calculus so that would be more on the level of your expertise to study, but it would make sense that if the ocean has been obsorbing most of the Co2, and what is it, half of the world population is located in the northern hemisphere, as are most of the industrial countries which would lead me to believe that they are somehow correlated.

    Why is the sea ice in the Antarctic not melting?

    This is the first I’m hearing of this. Last time I checked, it was melting, much quicker then expected. Didn’t the Laresn B Ice shelf colopase some decades ealier then expected?

    Why has Antarctica not warmed or even cooled in the last 20 years when we are at near record global temperatures?

    Possibly for the same reasons mentioned above about the Northern Hemisphere influencing the artic more rapidly then the antartic, considering most of the Co2 pollution comes from the Northern Hemisphere. If there’s a general “lage” in Co2 concentrations, like mentioned in another blog on this site, then that would lead me to believe that there’s a lag of the Co2 mixing from the nothern hemisphere into the sourthern hemisphere. How many data collectors are there in the Antartic anyways? Isn’t it almost impossible to reasearch there due to the conditions?

    And why was the Antarctic peninsula warming from 1940 to 1970 when the atmospheric temeratures were globally cooling?

    This is news to me, and is interesting. Where there less volcanic activity during this period? Are there El Nino’s, or La Nino’s that form in the southern pacific? Alot of questions to ask. Seems like not enough research has been done in the Southern Hemisphere. Well, I remember reading that research in the southern hemisphere is less extensive then that of the northern hemisphere as well.

    And why with all the melting in the Arctic, has sea level dropped over the past 20 years?

    Where is that coming from? You mean the “Artic sea level?” or worldwide sea level. That question isn’t very clear. Aren’t islands in the pacific being slowly depopulated because they are sinking? I’m assuming you mean the artic sea level? Wouldn’t geological features of the ocean basin under the ice cap reflect how the added water spread out? I know we’re still mapping the entire Earth’s ocean floor features, so I konw that there can’t be much information of what the land looks likes under the cap and artic ocean. That must have some sort of influence.

    My biggest question is, if there is a natural cycle, then why are we warming up when the cycle says we should be cooling?
    Theres obviously a lot of unknowns in this field and along with many other scientific fields. Thats the point of science. What I never understood, (and im not pointing you out specifically because I dont even know you or your field of expertise) is all these “scientists” like Linzden, who ask these sorts of questions. Why not do studies on them to figure them out? Isn’t that the point of a scientific question? is to obtain an answer? I’ve been hearing these sorts of questions for a couple years now, yet theres seems to be nobody studying why.

    Comment by Chris S — 18 Aug 2007 @ 9:15 AM

  144. Re #141. “Hansen’s cataclysm is only about ten months away, not years”. I think I’ll wait for the end of this summer’s ice melt before deciding whether to mark the date as next summer — or this one.

    “With no Arctic sea ice these regions will become deserts within a year, and the disrption to world agriculture will result in global famine.” You’re being a bit too definitive for my tastes here. While you may be correct, I don’t see where we can tell where the rains will fall. Desert perhaps, or jungle. (I also don’t know enough about hydrology. Can the water table deplete so fast as to create a desert in one year?)

    Comment by Sphere — 18 Aug 2007 @ 10:48 AM

  145. Re #139. “Why has Antarctica not warmed or even cooled in the last 20 years when we are at near record global temperatures?”

    Um, what about http://www.cdc.noaa.gov/map/images/fnl/sfctmpmer_365b.fnl.html ?

    Comment by Sphere — 18 Aug 2007 @ 10:50 AM

  146. [[Not saying that I really know what’s coming down the pike, but it’s too late to make any sort of societal change that will have a real effect. ]]

    I have to agree with you. To me it seems quite clear that 1) global warming is real, 2) human technology causes it, and 3) it’s a major problem. But I don’t think we’ll do anything about it in time to prevent a crisis. The human pattern is to let the disaster happen, then react. We don’t prevent crises.

    Comment by Barton Paul Levenson — 18 Aug 2007 @ 10:51 AM

  147. [[Why is the sea ice in the Antarctic not melting? ]]

    Who says it’s not melting?

    If you mean the extent of sea ice isn’t decreasing, that’s probably because there’s more calving at the edges, yes? You can’t be talking about the main body of ice, because since the disintegration of the Ross Ice Shelf a few years ago, that number is very definitely down.

    Comment by Barton Paul Levenson — 18 Aug 2007 @ 10:52 AM

  148. Re 147″ “disintegration of the Ross Ice Shelf ”

    That would be Larsen B. http://nsidc.org/iceshelves/larsenb2002/

    If the Ross goes then most likely the West Antarctic would quickly follow.

    Comment by Sphere — 18 Aug 2007 @ 11:47 AM

  149. re.141 the jet Stream is not moving northwards this side of the Atlantic. It is flowing streight across England, causing floods etc. This is further south than normal. the hot weather in the Mediterrainian must have some other cause. Something similer happened 20 years ago,when Southern Europe had record temperatures Northern Europe had persistant rain and cold temperatures.

    Comment by David Price — 18 Aug 2007 @ 11:53 AM

  150. Re #146: “But I don’t think we’ll do anything about it in time to prevent a crisis.”

    I was born in 1952, and I think it was already too late when I was born. Perhaps we could have done something to make the transition come later, or less suddenly, but I think the great coal burning of the 1800s had already sealed our fate.

    All we’re doing now is digging the hole deeper, and our only hope is for a few very big volcanic explosions.

    Comment by Sphere — 18 Aug 2007 @ 12:11 PM

  151. Well, between your opinion and Dr. Hansen’s, I’ll take Dr. Hansen’s.
    The leap from “not happening” to “too late” is from the denial playbook.
    I refute it thus: http://naturalscience.com/ns/articles/01-16/hansenFigure9.jpg

    Comment by Hank Roberts — 18 Aug 2007 @ 12:33 PM

  152. Re #115: By ‘Forcing’ do I take that figure as representing the yearly change in the increase in the surface energy balance? (Increase because the surface energy balance is increasing — otherwise known as global warming.) If so then any value other than 0 means some sort of geometric growth catastrophe (in the mathematical sense of catastrophe).

    [Response: Forcings are defined at the top of the atmosphere, not the surface. They in no way imply geometric growth catastrophes. - gavin]

    Comment by Sphere — 18 Aug 2007 @ 12:49 PM

  153. Re # 138: “I got it —- a 10-year window of opportunity to take decisive action.”

    Hank, if you want to stick your finger in the dike go ahead, but I’ll vote against building anymore levees surrounding New Orleans.

    I figure civilization has a 50-50 chance of surviving what’s coming, and humanity has a pretty good chance of surviving. I’ll worry about increasing the likelihood of civilization getting through this, and preserving information in case it doesn’t. I’ve given up on the notion of stopping it.

    Besides, from a global perspective this warming trend is minor. It only really matters to us and a few other large land animals.

    Comment by Sphere — 18 Aug 2007 @ 1:29 PM

  154. dhogaza wrote: “Why should it warm both poles somewhat equally?”

    Well mixed green house gases like CO2 should theoretically trap heat equally across the globe unless there is a mechanism of heat transport that moves heat unequally from the poles.

    Ocean currents generally speaking move heat from the equator to the poles, so we would need to answer the question how heat is being moved differently to the Arctic and Antarctic. Additionally then you would have to answer why CO2 has not heated the Antarctic proportionately despite the different hea transport mechanism. And if one could then show there was a offsetting change in heat transport, you should then ask if similar changes are happening in the Arctic. Most respected oceanographers will admit it is close to impossible to predict when and where the ocean will release heat trapped from decades, centuries and millenia gone by. There is still much to understand and much to debate.

    [Response: You have an incorrect understanding of the factors involved. Read our 2-year old post "Antarctic Cooling, global warming?". There is no contradiction at all between the predictions of anthropogenic climate change and the observation that inland Antarctica has cooled while the periphery has warmed. In fact, this is what the models predict. This nonetheless remains one of the favorites of the specious contrarian talking points. -mike]

    Comment by Jim Steele — 18 Aug 2007 @ 1:29 PM

  155. RE #150 [I think the great coal burning of the 1800s had already sealed our fate.]

    On what grounds do you base your opinion, which appears to be contrary to the general expert view? The amounts of anthropogenic CO2 pumped into the atmosphere in the 1900s, and hence the rise in its atmospheric concentration during that period, far exceed that in the 1800s. See AR4 report of WGI, Ch.2, FAQ2.1, figure 1, p.135. The forcing is logarithmic in the rise in atmospheric concentration (so for example each doubling from pre-industrial levels is expected to have roughly the same effect), but I have heard of no scientific argument that the amounts of CO2 added in the 1800s would be sufficient to cause dangerous climate change.

    Comment by Nick Gotts — 18 Aug 2007 @ 1:58 PM

  156. Re 155: “On what grounds do you base your opinion, which appears to be contrary to the general expert view?”

    First, I didn’t know there were experts on the question of what would have happened had greenhouse gas emission stopped about 1900.

    Second, the experts, your, and my opinions don’t really matter. The “decision” will be made by “mother nature”. What we have to do is decide what action we will take. I happen to be interested in the rather esoteric problem of defeating entropy; which implies a preference for assuming the worst and hoping for the best.

    In line with my interests, I’d propose taking some action to try to stop global warming, but assuming it to be largely unstoppable short run I’d put the bulk of effort into surviving the event as best we can. I wouldn’t waste effort trying to hold onto that which is most likely lost.

    Third, experts such as Christina Hulb have come about to my view — she was rather annoyed by the collapse of Larsen B and the rapid outflow of glaciers following that event. I didn’t really predict Larsen B, but I did predict that the shelves were holding back the glaciers.

    Comment by Sphere — 18 Aug 2007 @ 2:20 PM

  157. Hank Roberts (#151) wrote:

    Well, between your opinion and Dr. Hansen’s, I’ll take Dr. Hansen’s.
    The leap from “not happening” to “too late” is from the denial playbook.
    I refute it thus: http://naturalscience.com/ns/articles/01-16/hansenFigure9.jpg

    Looking at the article that the chart belongs to, I find it incredible how well the runs from the models fit the data. Of course, for someone who doesn’t know how the models work, someone who assumes that they are constructed by fitting the models to the data rather than being grounded in physics, it is all too easy to conclude that scientists merely tinkered with the formula until things fit. Afterall, this is just one chart. But there are so many charts, and the models are integrated such that if one tinkered with one part in order to make things fit a particular curve the other curves would take on bizarre forms which in no way fit the other curves.

    Looking at an article recently, which I am having some difficulty looking up, it stated that we had doubled the vertical resolution of the models both with respect to the atmosphere (from 20 to 40) and with respect the ocean (5 to 10, if I remember correctly), and then changed the horizontal resolution from 1.25 degrees to 1 degree, which means that the cross-sectional resolution has more than doubled. This is more or less standard nowadays. And that is since the 1990s, I believe. Likewise, a recent Hadley calculation involved an ensemble of over a thousand runs. Hansen’s 1988 was just a single run.

    Anyway, I will see if I can find the links – I believe I saved them somewhere.

    Comment by Timothy Chase — 18 Aug 2007 @ 2:23 PM

  158. Chris S Says: Isn’t there a large carbon sink in the southern hemisphere that was recently studied and deemed “completely saturated of Co2″? Maybe that’s the reason.

    Perhaps Chris you could show me a link where “atmospheric CO2” concentrations are not well mixed, especially around Antarctica? The sink notion is meaningless in this context if the atmospheric concentrations of CO2 are equally distributed.

    You mention the difference may have to do with polluting populations in the northern hemisphere but again you are assuming atmospheric CO2 concentration are NOT equally mixed. I believe the answers have more to do with natural cycles and processes that are being minimized in this debate. Likewise for ozone holes. You would expect bigger ozone holes in the northern hemisphere near the polluting centers. However just the opposite is the case and it is the Antarctic not Arctic that gets ozone holes.

    Chris S Says: “This is the first I’m hearing of this. Last time I checked, it was melting, much quicker then expected. Didn’t the Laresn B Ice shelf colopase some decades ealier then expected? “
    Read the following by researchers who wrote much of the IPCC’s information on polar climates.
    A synthesis of Antarctic temperatures
    by William L. Chapman and John E. Walsh
    http://igloo.atmos.uiuc.edu/Antarctic.paper.chapwalsh.2005.pdf
    They conclude, “Trends computed using these analyses show considerable sensitivity to start and end dates with starting dates before 1965 producing overall warming and starting dates from 1966-1982 produce cooling rates over the region.”
    So if we start from 1966, isn’t it odd that during such a period of “dramatic warming” in the last 4 decades that Antarctica is cooling!?! Most CO2 advocates like to use before 1965 trends to dismiss this theoretical problem and so contend there is still a warming trend. I find that to be more spin than good scientific inquiry!

    And it is true that we lost the Larsen B ice shelf and any measure of melting in Antarctica is founds only in the this area of western Antarctica and represents about a tenth of the Antarctic ice. The eastern Antarctica show no such melting by most measures.

    There are several studies showing sea ice is generally expanding in area and extent in most of the Antarctic but with a decrease in the western area. Overall the sea ice is increasing.
    Here is a link to the abstract of a 2004 paper “Interpretation of recent Antarctic sea ice variability”
    http://www.agu.org/pubs/crossref/2004/2003GL018732.shtml
    And here is a link to a map showing that while the atmosphere was cooling globally, the area of the Larsen B ice shelf was still warming. This strongly suggests that ocean currents and stored heat may be more responsible than atmospheric warming and CO2.

    http://en.wikipedia.org/wiki/Image:Global_Cooling_Map.png

    Chris S Says: “Where is that coming from? You mean the “Artic sea level?” or worldwide sea level. That question isn’t very clear.”

    My apologies I should have specifically said Arctic sea level. Here is a link: http://news.bbc.co.uk/1/hi/sci/tech/5076322.stm

    They found over the past 10 years “Arctic sea level has been falling by a little over 2mm a year“

    Sphere Says: “Um, what about http://www.cdc.noaa.gov/map/images/fnl/sfctmpmer_365b.fnl.html?”

    Umm sphere I am not sure what your link is suppose to tell me. But I am an ignorant naysayer. Please explain. Read the Chapman & Walsh paper I linked to.

    Comment by Jim Steele — 18 Aug 2007 @ 2:25 PM

  159. Re #153 [Besides, from a global perspective this warming trend is minor. It only really matters to us and a few other large land animals.]

    On what is your opinion based?

    How about coral reefs and all the marine life depending on them, species in tropical forests likely to turn to savannah, marine animals which build shells of calcium carbonate (due to ocean acidification), high-altitude fauna and flora?

    According to Thomas, Cameron et al “Extinction risk from climate change” (NATURE |VOL 427:145-8, 8 JANUARY 2004 http://www.gbltrends.com/doc/nature02121.pdf) somewhere between 15% and 37% of a broadly distributed sample of species will be “committed to extinction” due to climate change by 2050, but prompt action can make the higher part of that range less likely.

    Another recent study (Climate simulation of the latest Permian: Implications for mass extinction JT Kiehl, CA Shields – Geology,33;9;p. 757-760 2005), the greatest known mass extinction in Earth history was probably caused by CO2-induced global warming (in this case due to massive volcanic eruptions), of about 6C. This amount of warming is within the range of possibilities if (but according to expert opinion only if) we do not take serious action to reduce greenhouse gas emissions.

    Comment by Nick Gotts — 18 Aug 2007 @ 2:34 PM

  160. PS to #156

    The resolution comparisons are:
    Verical was 19 levels of atmosphere, now 38 levels, the ocean was calculated as 20 levels and now as 40 levels for the first 5 km, the horizontal resolution was 1.25 degrees by 1.25 degrees but is now 1 by 1. And that is the advance from the 1990s to present.

    See:

    Models ‘key to climate forecasts’
    By Dr Vicky Pope
    UK Met Office’s Hadley Centre
    http://news.bbc.co.uk/1/hi/sci/tech/6320515.stm

    Comment by Timothy Chase — 18 Aug 2007 @ 2:45 PM

  161. Re 159:

    “Re #153 [Besides, from a global perspective this warming trend is minor. It only really matters to us and a few other large land animals.]

    On what is your opinion based?”

    My opinion.

    “How about coral reefs and all the marine life depending on them, species in tropical forests likely to turn to savannah, marine animals which build shells of calcium carbonate (due to ocean acidification), high-altitude fauna and flora?”

    Tropical coral reefs have had to move in the past, and I’m sure will have to move in the future. We’re just an annoyance.

    “According to Thomas, Cameron et al “Extinction risk from climate change” (NATURE |VOL 427:145-8, 8 JANUARY 2004 http://www.gbltrends.com/doc/nature02121.pdf) somewhere between 15% and 37% of a broadly distributed sample of species will be “committed to extinction” due to climate change by 2050, but prompt action can make the higher part of that range less likely.”

    The higher range seems believable. I’m not at all convinced about the “prompt action” part. I’m inclined to think that the best we can do is make the mess we’ve created slightly better.

    “Another recent study (Climate simulation of the latest Permian: Implications for mass extinction JT Kiehl, CA Shields – Geology,33;9;p. 757-760 2005), the greatest known mass extinction in Earth history was probably caused by CO2-induced global warming (in this case due to massive volcanic eruptions), of about 6C. This amount of warming is within the range of possibilities if (but according to expert opinion only if) we do not take serious action to reduce greenhouse gas emissions.”

    Interesting….

    Comment by Sphere — 18 Aug 2007 @ 3:43 PM

  162. Re #161 [Re 159:

    “Re #153 [Besides, from a global perspective this warming trend is minor. It only really matters to us and a few other large land animals.]

    On what is your opinion based?”

    My opinion.]

    I think that probably tells us all we need to know about whether we need to take anything you say seriously.

    Comment by Nick Gotts — 18 Aug 2007 @ 3:58 PM

  163. Re #152 and Gavin’s response that forcings are defined at the top of the atmosphere.

    Is it any wonder that the scientists have got the melting of the Arctic sea ice completely wrong? They are measuring the forcing at the top of the atmosphere (TOA) when the sea ice that is melting is at an altitude of 0 m (0 feet) ASL (above sea level.) i.e. the bottom of the atmosphere (BOT)!

    It is fairly obvious to anyone that the melting is due to the increase in CO2, which is raising the snowline and causing the Alps to melt. See Alps host mass naked photo shoot. The snowline has now risen to at least 10 m (30 feet) at the poles. That means the end of the Arctic sea ice, but not the ice at the South Pole where the altitude is 2,835 m (9,300 feet.)

    Can I just point out that Gavin is wrong anyway. The forcing is not measured at the TOA. It is measured at the tropopause. See the glossary in the latest IPCC assessment report (AR4) where it states:

    Radiative forcing is the change in the net, downward minus upward, irradiance (expressed in W m–2) at the tropopause due to a change in an external driver of climate change, such as, for example, a change in the concentration of carbon dioxide or the output of the Sun.

    Had I made such an elementary mistake I am sure Gavin would have been down on me like a sack of coals, just as he was when I suggested that the sudden drop in CO2 concentration above 80 km is due to the CO2 molecule being heavier than other air molecules.

    The point is that just because science is correct does not mean that scientists are correct. Science is what the scientists got right – not what they believed, such as the existence of phlogiston and aether, or their disbelief in ice ages, meteoric and cometary impacts,and continental drift. Even the Croall-Milankovitch theory of astronomy induced ices ages was long held in doubt.

    You don’t have to be a Galileo to have your correct ideas doubted.

    I rest my case :-)

    [Response: If you want to be picky, then forcing is best defined as the adjusted change in forcing once the stratospheric temperatures have adjusted. At that point, there is no net flux divergence in the stratosphere (since it is neither cooling nor warming) and therefore the forcing at the tropopause is identical to that of the TOA. The tropopause/TOA distinction is only important for the instantaneous forcings. - gavin]

    Comment by Alastair McDonald — 18 Aug 2007 @ 4:13 PM

  164. Re #156 [First, I didn’t know there were experts on the question of what would have happened had greenhouse gas emission stopped about 1900.] There are reasonable well-founded estimates of the sensitivity of the climate system to GHG levels in the atmosphere, frequently discussed on this site. If these are anywhere near right, the amount put into the atmosphere before 1900 would not have caused dangerous climate change.

    [Third, experts such as Christina Hulb have come about to my view — she was rather annoyed by the collapse of Larsen B and the rapid outflow of glaciers following that event.]

    I assume you mean Christina Hulbe. In what sense has she come about to your view? Do you mean she agrees with you AGW sufficient to make the collapse of civilisation likely is almost certainly unstoppable?
    Here’s something she posted on 11th May 2007 (http://www.theleftcoaster.com/archives/010309.php#010309) – she’s summarising the IPCC report, but gives no indication she disagrees with it:
    “First, technologies already exist to accomplish meaningful greenhouse gas (GHG) stabilization goals. Second, the costs of mitigation are manageable (estimates range from small gains in GDP to costs in the few percent of GDP range). Third, there are significant co-benefits to mitigation, including economic growth in some sectors, public health, and energy & food security.”

    [I did predict that the shelves were holding back the glaciers.]
    When and where?

    Comment by Nick Gotts — 18 Aug 2007 @ 4:32 PM

  165. [[Re 147″ “disintegration of the Ross Ice Shelf ”

    That would be Larsen B. http://nsidc.org/iceshelves/larsenb2002/

    If the Ross goes then most likely the West Antarctic would quickly follow.]]

    Oops. Sphere got that right and I got it wrong. My bad.

    Comment by Barton Paul Levenson — 18 Aug 2007 @ 4:42 PM

  166. Hank — Please don’t call me a denialist. I’m nothing of the sort. I fully intend to support and work for efforts to conserve energy and develop renewable energy sources and, if it will help, carbon sequestration. I’m just saying that I expect to lose.

    Comment by Barton Paul Levenson — 18 Aug 2007 @ 4:46 PM

  167. Re #166 where Barton writes:

    I fully intend to support and work for efforts to conserve energy and develop renewable energy sources and, if it will help, carbon sequestration. I’m just saying that I expect to lose.

    Barton,

    If only Hank, Gavin, and everyone else would face up to how serious the situation really is then perhaps we would not lose. But while scientists like Gavin find it more fun to argue with ignorant denialists about 1934 than to confront the real issues of life after Arctic Ice, then there is little hope for the planet.

    Comment by Alastair McDonald — 18 Aug 2007 @ 5:50 PM

  168. One thing I have noticed from the map is that the North West Passage is now open. Will there be a lot of ships sailing through it in Summer now? Will this cause further loss of ice?

    Comment by David Price — 18 Aug 2007 @ 6:25 PM

  169. Mike a moderator said “You have an incorrect understanding of the factors involved. Read our 2-year old post “Antarctic Cooling, global warming?”. There is no contradiction at all between the predictions of anthropogenic climate change and the observation that inland Antarctica has cooled while the periphery has warmed. In fact, this is what the models predict. This nonetheless remains one of the favorites of the specious contrarian talking points. -mike]”

    [edited] I did read your site’s explanation for Antarctica cooling and I found it somewhat vague and wanting. First of all using the global mean average does nothing to support or deny the effects of CO2 warming. Averages can obscure causal relationships. Your explanation mentions winds, oceans and stratosphere and various heat transport mechanisms as possible explanations as to why the Antarctic is cooling. I certainly agree they all play critical a role. My point is that those same heat transport mechanisms may also play a role in the warming of the Arctic. And those mechanisms may have easily caused the Arctic to warm to a greater degree than the Antarctic that we witness a net gain in average temperature. We see unequal development of polar ozone holes due to natural factors, why not warming. Using the average temperature explains nothing but allows you to mire your analysis in circular thinking.

    [edited]

    Your explanation also refers to the southern hemisphere’s ocean’s absorbing the heat. If that hypothesis is true we should see the ocean’s warming. However the Lyman 2006 paper shows that while there are some areas of warming there are at least equally vast areas of the southern oceans that are cooling in particular around Africa. (And that data is not part of the suspect Argo float errors which are mostly in the North Atlantic)

    And perhaps you can site papers and models that explain why the Antarctic peninsula was warming when there was recent global cooling? Otherwise I am inclined to believe that past heat from the ocean is more critical to the ice shelf collapse than atmospheric and CO2 induced warming.

    Comment by J. Steele — 18 Aug 2007 @ 6:34 PM

  170. I was replying to Sphere, not to what you posted, Barton.
    I apologize that it seemed I was replying to you.
    I disagree that it is too late to do anything.
    I may agree with you (I think) that history argues against being hopeful.

    But history is mostly about what people thought and did without science to help.

    I remind myself that, in the whole of human life on Earth, only a few tens of thousands of people have been scientists, and those in the last couple of centuries. In that way, science is providing one hell of an effective candle, all of a sudden, after many thousands of years of darkness.

    Almost every human choice has been made without any way of understanding long term trends and indirect effects and external costs. Only the last maybe fifty years have decisions started to be made that _assume_ the need to ask what science can offer. Most of our stories of hope are the ‘first time’ stories — the Broad Street Pump, for example. Anyone who knows even a bit of science will probably know that story. People who don’t —- can learn.

    David Brin says this far better, in quite a few places.

    Comment by Hank Roberts — 18 Aug 2007 @ 6:44 PM

  171. I assume you mean Christina Hulbe. In what sense has she come about to your view? Do you mean she agrees with you AGW sufficient to make the collapse of civilisation likely is almost certainly unstoppable?

    I’ve never heard her say that, and I drink beer with her [edit] on a fairly regular basis.

    [edit - no personal information about 3rd parties please]

    AFAIK she holds to mainstream scientific views regarding climate issues. The quote you provide from this past May is consistent with everything I’ve heard her say about the subject.

    Comment by dhogaza — 18 Aug 2007 @ 6:49 PM

  172. Chris S Says: Isn’t there a large carbon sink in the southern hemisphere that was recently studied and deemed “completely saturated of Co2″? Maybe that’s the reason.

    Then Jim Steele said:

    Perhaps Chris you could show me a link where “atmospheric CO2” concentrations are not well mixed, especially around Antarctica? The sink notion is meaningless in this context if the atmospheric concentrations of CO2 are equally distributed.

    Jim, you don’t need a link, a map will suffice. All that blue ink you see represents salt water …

    Comment by dhogaza — 18 Aug 2007 @ 6:51 PM

  173. > show me a link where “atmospheric CO2” concentrations are not well mixed, especially around Antarctica?
    > The sink notion is meaningless in this context if the atmospheric concentrations of CO2 are equally distributed.

    That doesn’t make sense. It seems like you’re saying it logically can’t happen?
    But nature answers.

    Air circulates and mixes a lot faster than water; we know CO2 is well mixed over a few years’ time in the atmosphere (Mauna Loa can track seasonal variations from particularly strong or weak growing seasons at different places around the globe, when they come ’round over the Pacific long afterwards, before they get mixed in, the Mauna Loa observatory has a description of that).

    The ocean sink is described here, and many other places in the news of the time:
    http://news.bbc.co.uk/2/hi/science/nature/6665147.stm

    The article mentions Dr. Corinne Le Quere, whose work is in this area. I’ve said before I hope RC can get Dr. Le Quere in at some point. I notice that she is talking about improving the climate models by paying specific attention to the different kinds of plankton that create this part of the carbon cycle and how they change — which is going to be very interesting once it’s in the models.

    The same BBC article also quotes Dr. Sus Honjo of WHOI:

    “…. technology now made possible very detailed monitoring of marine carbon sinks, with some data available in real time.
    ‘We have been way behind the modellers, who are hungry for numbers. But now we are starting to catch up because of the new tools and instruments available’…”

    It’s real.

    Comment by Hank Roberts — 19 Aug 2007 @ 12:36 AM

  174. Hank Roberts Says:

    > The sink notion is meaningless in this context if the atmospheric concentrations of CO2 are equally distributed.

    “That doesn’t make sense. It seems like you’re saying it logically can’t happen?
    But nature answers.”

    Hank you have cnfused me. Are you arguing that the ocean carbon sinks explains the cooling in Antarctica?

    I do not see why you would think I am arguing that a sink does not exist. Nor was I arguing that short term asymmetries in atmospheric CO2 can not exist. You have taken my points out of context.

    However I am most assuredly arguing against the above suggestion that the existence of a southern ocean carbon sink will create an atmospheric asymmetry that lead to east Antarctica cooling while west Antarctica warms. As a sink will gradually absorbs CO2, the atmospheric CO2 immediately readjusts to the change in partial pressures. Only singular explosive events like a volcanic eruption would cause measurable atmospheric asymmetries. I suppose someone here could call the sink explanation specious.

    Comment by Jim Steele — 19 Aug 2007 @ 10:20 AM

  175. It seem that the worst thing one can be labelled is as a ‘Climate change denialist’. It is a catch-all, hence when I say that at best I see selective use of particular data to support a particular argument I will be no doubt pilloried. Ignoring the scientific process is counter-productive and dangerous.

    Comment by Dr Andrew Iles — 19 Aug 2007 @ 11:00 AM

  176. Dr Andrew Iles (#175)

    It seem that the worst thing one can be labelled is as a ‘Climate change denialist’. It is a catch-all, hence when I say that at best I see selective use of particular data to support a particular argument I will be no doubt pilloried. Ignoring the scientific process is counter-productive and dangerous.

    Hardly.

    Among those who are particularly active and who consequently have every reason to know its real and to understand its causes, there exist different types with different clusters of motivation. However, motives don’t even enter consideration until one has had the chance to examine the arguments and the evidence. Nothing to worry about assuming your arguments are valid and you have the evidence to marshall, or alternatively that you are willing to abandon your position once it has been shown to be untenable.

    Comment by Timothy Chase — 19 Aug 2007 @ 12:17 PM

  177. Re #175 [when I say that at best I see selective use of particular data to support a particular argument I will be no doubt pilloried.]

    Well, you might at least be asked to specify where you see it, so your claim can be responded to in a useful way.

    Comment by Nick Gotts — 19 Aug 2007 @ 12:25 PM

  178. when I say that at best I see selective use of particular data to support a particular argument I will be no doubt pilloried.

    You’ll be pilloried for waving your hands and saying “I don’t believe the science” without providing any specifics.

    Ignoring the scientific process is counter-productive and dangerous.

    Then don’t do it.

    Comment by dhogaza — 19 Aug 2007 @ 12:43 PM

  179. Er, could you be a bit more specific? Was it something I said?

    Comment by Hank Roberts — 19 Aug 2007 @ 1:13 PM

  180. Re #179

    Hank,

    I don’t think anyone is criticizing you.

    But if you are really paranoid then ‘could you be a bit more specific?’ What is the number of the post that you think is attacking you?

    Comment by Alastair McDonald — 19 Aug 2007 @ 3:19 PM

  181. re: #175-179:

    EITHER
    “Dr Andrew Iles” is a reasonable person with a real issue, but the post was minimally-contentful and seemed OT. Usually, if ignored, reasonable people will try again without being asked, and perhaps articulate their point well enough that a) It can be seen to be on-topic and b) a reasonable conversation can ensue.

    OR
    DBAT: Drive-By Anonymous Troll … successfully helping clutter a useful discussion with junk & replies to junk.

    Hence, I suggest IGNORE is a productive first-look strategy.

    Comment by John Mashey — 19 Aug 2007 @ 3:36 PM

  182. Yup, sorry Alastair, I meant that as a reply to Iles, failed to point to it explicitly. John Mashey has the better reply (at 3:36pm)

    Comment by Hank Roberts — 19 Aug 2007 @ 4:52 PM

  183. Alastai:r McDonald (#180) wrote

    Hank,

    I don’t think anyone is criticizing you.

    But if you are really paranoid then ‘could you be a bit more specific?’ What is the number of the post that you think is attacking you?

    Alastair, I doubt that he was responding to you when Hank Roberts (#179) humorously wrote:

    Er, could you be a bit more specific? Was it something I said?

    In fact, I believe he was responding to the following (#175):

    It seem that the worst thing one can be labelled is as a ‘Climate change denialist’. It is a catch-all, hence when I say that at best I see selective use of particular data to support a particular argument I will be no doubt pilloried. Ignoring the scientific process is counter-productive and dangerous.

    I suspect that I am much more likely to experience a degree of paranoia than Hank, but if I were putting together a descending list, there are others who I would place much closer to the top of it.

    Comment by Timothy Chase — 19 Aug 2007 @ 5:35 PM

  184. http://www.jpl.nasa.gov/news/features.cfm?feature=1315

    It seems that at the moment the only part of the arctic with anything like a ‘normal’ ice extent or area is leeward of Greenland. Is there any reason at all to believe the current over 2 million anomaly in Arctic sea ice area is just normal variation?

    While I’m not ready to declare that 2007 is the transition year, I do think there is every reason to believe it might well be the year. I doubt this winter will support a sufficient recovery to push the “switch” off another year.

    (I do believe in the butterfly catastrophe theory of systems, and do expect that whenever the change happens it will be sudden. That doesn’t mean that I have any idea on when the catastrophic change will occur.)

    Comment by Sphere — 19 Aug 2007 @ 7:57 PM

  185. re: 138 “10-year window of opportunity to take decisive action.”

    Can someone inform us lurkers exactly what this means? It’s commonly used, yet uncommonly defined.

    How decisive must the action be?

    What must be done?

    What is the economic costs (for the average us citizen) for this decisiveness?

    I am sure there are millions of us wanting to help, changing light bulbs etc… but does this really matter?

    Comment by Anthony Shafer — 20 Aug 2007 @ 3:58 AM

  186. re 148

    Re 147″ “disintegration of the Ross Ice Shelf ”

    That would be Larsen B. http://nsidc.org/iceshelves/larsenb2002/

    If the Ross goes then most likely the West Antarctic would quickly follow.

    ==================

    A general query.

    Larsen is a separate Ice Shelf near the tip of the West Antarctica penninsule. The next closest and adjoining Ice Shelf is the Ronne. The Ross Ice Shelf is about 1,000 kilometers away, across a swath of land separating it from the Ronne.

    http://nsidc.org/data/atlas/

    While the Ross touches both East and West Antarctica, wouldn’t the result be more impactful to East Antarctica?

    And wouldn’t the disintigration of the Larsen Shelf be enough to set off the West?

    Comment by J.S. McIntyre — 20 Aug 2007 @ 10:04 AM

  187. Re #185 Sir David King, the UK Government’s chief scientist spelt out what has to be done to the AAAS last month. See http://www.aaas.org/news/releases/2007/0718king.shtml

    In summary he is saying that we need an international agreement on sharing and reducing the use of fossil fuels to be signed by 2009 and effective from 2012.

    Since it seems highly unlikely that George Bush would sign up to such an agreement, then avoidance of catastrophic climate change seems inevitable.

    This will lead to worldwide famine and a collapse of the global economic system, which will throw millions of Americans out of work, roaming the streets, all armed with guns.

    You can read a report prepared for the Pentagon about the consequences of catastrophic climate change here:
    http://www.gbn.com/ArticleDisplayServlet.srv?aid=26231

    Comment by Alastair McDonald — 20 Aug 2007 @ 10:22 AM

  188. [[re: 138 “10-year window of opportunity to take decisive action.”
    Can someone inform us lurkers exactly what this means? It’s commonly used, yet uncommonly defined.
    How decisive must the action be?
    What must be done?
    What is the economic costs (for the average us citizen) for this decisiveness?
    I am sure there are millions of us wanting to help, changing light bulbs etc… but does this really matter
    ]]

    It matters. If we don’t massively change our CO2 output in about a decade, anthropogenic global warming is likely to trip geophysical feedbacks which will amplify it greatly. At that point it will be impossible to stop and humanity will suffer.

    To stop AGW would require a massive shift to conservation, and away from fossil fuels to renewable sources of energy. I don’t think it’s going to happen, although I will work for it right up to the end. I think we’re out of luck just due to the strong tendency of human beings to do nothing about a crisis until the crisis actually hits. Prevention isn’t in our nature.

    Comment by Barton Paul Levenson — 20 Aug 2007 @ 11:14 AM

  189. Re 185. Anthony, there is NO ten year window.

    The opportunity to stabilise warming at 1 degree C has been thrown away.

    Taking the study by Baer and coworker as an example,

    http://www.ippr.org.uk/publicationsandreports/publication.asp?id=501

    there is little time left before the opportunity to restrain warming to 2 degree C, to avoid dangerous climate change with its positive feedbacks etc, is lost. Their study (which is representative of recent emission pathway studies) suggests that global C02 emissions should peak by 2010. Measured in days that is about 1000 days to deliver the peak.

    It is instructive to plot out the graphs in the Baer study as they show the ghg emissions turning that must be delivered. If the results of the global endeavour are going to be seen within 1000 days, it requires leaders to have delivered executable emission reductions plans well before then.

    The profiles in the Baer study are doable.

    Comment by Michael — 20 Aug 2007 @ 11:35 AM

  190. “10 year window” (maybe 9 by now?) means — _have_made_changes_ within the ten years.

    It’s up to the big coal power plant builders, at this point, to do the right thing the smart way fast.

    Remember — there’s no sign of intelligent life in the universe, with the possible exception of Earth. They have the chance to decide, for this planet.

    Comment by Hank Roberts — 20 Aug 2007 @ 12:19 PM

  191. There is no 10 year window. There is a window of a few hundred days.

    There is an absolute requirement on leaders to deliver on their Duty of Care. That is a legal Duty. The Duty is not confined to leaders within the coal industry.

    Comment by Michael — 20 Aug 2007 @ 1:14 PM

  192. re 191. erratum. should have written coal-fired power station industrial sector.

    Comment by Michael — 20 Aug 2007 @ 1:17 PM

  193. Jim S, – I hope you didn’t take the comment about confusing Arctic and Antarctic towards you. That would be the last thing I would imply on THIS site of all of them. It was a simple expression of how uneducated most American’s really are about the world around them. We are so caught up in our daily lives that like many have stated here over and over “humanity does nothing about a crisis until it hits”. That’s so very true, and so very disturbing. That was a real situation I found my self in when arguing with someone about the “existence” of AGW. Yet they still argue with you. I wasn’t speaking on the terms of scientists but everyday people on the issue.

    As someone studying to be in this field in the future, the one thing I will never do is say “that can’t be”. There’s PLENTY we don’t know like you bring up some good points. The Antarctic apparently is a mystery, BUT, I don’t find one missing link in the network of data and evidence on AGW and Climate Change strong enough evidence to denounce the cause of AGW. Hey, Maybe 5, 10, 50 years from now there will be some extraordinary discovery that explains all of this. The question is do we want to sit and wait on that discovery, or try to prevent the collapse of modern civilization. I am more then convinced that this is the case, and it has even made me wonder if bringing a child into this world would be worth it!

    You have to remember Jim, there are plenty of corrupt people in the world, many who will use their “power” or “expertise’ for the all mighty dollar. I’m sure your aware of ExxonMobil and those stories of hiring scientists to write papers, etc.

    In my Core required class, Public Speaking, we had to do a debate. This kid and I did it on the “Cause of GW” not so much it’s existence. He didn’t deny that it the earth was warming etc, but on the day of the presentation debate, he must have had about 15 packets of information, all at his disposal. I won the debate, while some even laughed at him throwing out random “causes” such as “Mar’s is warming, so…” . Come to find out his best friends father is vice president of ExxonMobil. Well go figure.

    I don’t know your area of expertise, just out of curiosity because obviously, I have no level, besides knowing the topic very well. lol. I hope I didn’t “offend” you whatsoever, and those questions I asked you were real questions I had.

    Thanks, Chris.

    Comment by Chris S — 20 Aug 2007 @ 2:43 PM

  194. (185, 191) Thanks for the links Michael, all I have had time for was the conclusion… which is quite frightening. In all reality here- an unscientific question is where does the community feel we’ll peak at Co2?

    Can anyone point me to more of a layman’s scenario per degree? Has there been any attempt to cross reference bio-diversity/social/political/economic/climate ramifications per degree change all in one place?

    Thank you again for all that you do!

    Comment by Anthony Shafer — 20 Aug 2007 @ 2:55 PM

  195. Can anyone point me to more of a layman’s scenario per degree?

    Six Degrees, by Mark Lynas (http://www.marklynas.org/sixdegrees)

    Comment by Gareth — 20 Aug 2007 @ 3:30 PM

  196. A little off-topic here, but you have been talking up Co2 a bit lately. What is your take on this story?

    “Biofuels switch a mistake, say researchers”

    http://www.guardian.co.uk/environment/2007/aug/17/climatechange.energy

    Comment by Gary — 20 Aug 2007 @ 3:52 PM

  197. 194 & 195. The book by Mark Lynas is an excellent book, although does not attempt to describe, for example, the economic implications per degree. The book provides, however, an excellent background with which to assess implications of each degree from various (eg economic, critical infrastructure, biodiversity) perspectives. One way of doing this is to define a Richter scale for an entity/system under consideration and then read through the book, degree by degree, and assess a Richter-level impact corresponding to each degree. Accumulated bundles of temperature-dependent Richter profiles provide insight into mitigation requirements.

    Comment by Michael — 20 Aug 2007 @ 3:55 PM

  198. Chris S Says:
    20 August 2007 at 2:43 PM
    Jim S, – I hope you didn’t take the comment about confusing Artic and Antartic towards you. That would be the last thing I would imply on THIS site of all of them. It was a simple expression of how uneducated most American’s really are about the world around them.

    Chris, I applaud your curiosity. The problem here is that the term debate is political, not scientific. The sciefintic arena on this topic (AWG) has been confused with politics. The duty of a scientist is to examine all information and come to a conclusion of the question asked (hypothesis) no matter where the funding came from. It is the scientists duty to evaluate all information that has been provided and check it against this hypothesis. It makes no difference who funded the scientific study. We have in science reached an area of Kill the messenger because it does not support our position and will therefore impact our funding. From both sides the change has become character assignation – one side more than the other. I implore you to do some research and you will find that at one time All scientists , 2,000, 1700, 600, 300, have agreed that man is responsible for Global Warming, now called Climate Change. It does not take an Einstein to realize that people are playing with numbers to fortify their positions and funding and or their ego.

    As far as procreating – no matter how you choose, your children will live in a different world than you have known.

    Good luck with your endeavors and always look for the truth.

    Comment by pbview — 20 Aug 2007 @ 4:44 PM

  199. Re #186: “While the Ross touches both East and West Antarctica, wouldn’t the result be more impactful to East Antarctica?”

    The West Antarctic is considered less stable because more of the ice is below sea level. (I think there is also a slope more conductive to ice flow, but am not sure on that.) It is expected that it will require less climatic change for it to collapse.

    Comment by Sphere — 20 Aug 2007 @ 5:30 PM

  200. Re #188: “It matters. If we don’t massively change our CO2 output in about a decade, anthropogenic global warming is likely to trip geophysical feedbacks which will amplify it greatly. At that point it will be impossible to stop and humanity will suffer.”

    Please fit today’s approximately 2 and a quarter million anomaly in the Arctic Ice Area into your timeline. I’ll note first that there has been a growing anomaly for several years in succession, and second that with about a half month to go in the expected ice melt we are currently about 2/3 million below the previous known minimum.

    Comment by Sphere — 20 Aug 2007 @ 5:37 PM

  201. A significant event, such as a major pyroclastic in Alaska, might cause a full recovery in the ice this winter. Given that there hasn’t been a full recovery for three or four years now, absent a major event is it possible for a reasonable recovery to happen this winter from normal variation? In other words, aren’t we pretty sure of starting next year with a deficit? (Major volcanic explosions seem to have approximately 18 months of effect.)

    Comment by Sphere — 20 Aug 2007 @ 6:18 PM

  202. If the fragment of sea surface ice hanging on between the Kara Sea and the East Siberian Sea goes in the next few weeks…

    http://arctic.atmos.uiuc.edu/cryosphere/
    http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/recent365.anom.region.1.html

    will that allow the establishment of a surface-water wind-driven gyre between the Atlantic and Pacific carrying the warm water already pushing so hard along that coast?

    http://www.emc.ncep.noaa.gov/research/cmb/sst_analysis/images/wkanomv2.png

    And if that happens – if increasingly dynamic as well as warmer sea surface conditions establish in the next few weeks will it not significantly reduce the opportunities for re-freezing of the surface waters? I can imagine a lot of fog, and very little freezing going on – like on the Grand Banks off New Foundland.

    Would that be a tipping point?

    Comment by Nigel Williams — 20 Aug 2007 @ 7:26 PM

  203. Re #202: “And if that happens – if increasingly dynamic as well as warmer sea surface conditions establish in the next few weeks will it not significantly reduce the opportunities for re-freezing of the surface waters? I can imagine a lot of fog, and very little freezing going on – like on the Grand Banks off New Foundland.

    Would that be a tipping point?”

    I was just thinking about the shipping and geopolitical implications… Interesting question.

    (But I do think that the tipping point has already been reached — barring geological intervention.)

    Comment by Sphere — 20 Aug 2007 @ 7:59 PM

  204. With posters talking about climate tipping points, why would my statement about no sunspots and climate cooling be removed? Why is censorship needed when posts are respectful?

    [hint: see comment #7 of our comment policy]

    Comment by Steele — 20 Aug 2007 @ 9:56 PM

  205. Chris,

    I am a biologist. Here is a link to my field station- http://www.sfsu.edu/~sierra/ I am seeking the truth, but do not buy the CO2 hypothesis. I had hoped that this would be a place for debate but I have had my posts blocked and edited. I would think if the evidence was so strong there would be no need for such tactics.

    [again, please see comment #7 of our comment policy]

    Comment by Steele — 20 Aug 2007 @ 10:00 PM

  206. I would think if the evidence was so strong there would be no need for such tactics.

    [again, please see comment #7 of our comment policy]

    After reading comment #7 it would appear anything that disagrees with the CO2 hypothesis for warming could be labeled specious or misleading. How then does one have a debate or question your CO2 assumptions or omissions without be censored?

    Comment by Steele — 20 Aug 2007 @ 10:58 PM

  207. re 199

    Re #186: “While the Ross touches both East and West Antarctica, wouldn’t the result be more impactful to East Antarctica?”

    The West Antarctic is considered less stable because more of the ice is below sea level. (I think there is also a slope more conductive to ice flow, but am not sure on that.) It is expected that it will require less climatic change for it to collapse.

    =====================

    I understand that. Part of my question focused on the fact the West Antarctic Penninsula, if you look at the map I provided, is apparently less affected by the Ross than it is by the Larsen and a number of smaller shelfs butted up against the penninsula proper.

    http://nsidc.org/cgi-bin/atlas_south?zoomdir=0&zoomsize=2&zoom_to=&glossary_term=&layer=south_pole_geographic&imgxy=250.0+250.0&imgext=-3253263.394320+-1735073.810304+1265157.986680+2783347.570696&map=%2FWEB%2FINTERNET%2FMMS%2Fatlas%2Fcryosphere_atlas_south.map&savequery=true&mapext=shapes&layer=land&layer=coastlines&layer=copyright&layer=&layer=glacier_outlines&layer=sea_ice_extent_01&layer=snow_extent_01

    http://en.wikipedia.org/wiki/Image:Ant-pen_map.png

    The majority of current glacial reduction in the WAP is apparently happening in those areas, and it would seem the Ronne and its status would be more important to the WAP than the Ross Shelf, which, as I pointed out, is a thousand kilometers from the Ronne and the Weddell sea … and a thousand kilometers from the base of the WAP.

    Comment by J.S. McIntyre — 20 Aug 2007 @ 11:09 PM

  208. Re #206: “The majority of current glacial reduction in the WAP is apparently happening in those areas, and it would seem the Ronne and its status would be more important to the WAP than the Ross Shelf, which, as I pointed out, is a thousand kilometers from the Ronne and the Weddell sea … and a thousand kilometers from the base of the WAP.”

    I guess we were talking past each other then. Your analysis of the WAP seems reasonable. The WAP certainly is being effected by the breakup of Larsen B — as well as by general warming. I don’t know how much land ice is contained in the WAP. If it disintegrates is this likely to raise the sea level sufficiently to dislodge the West Antarctic ice?

    Comment by Sphere — 21 Aug 2007 @ 6:15 AM

  209. Re #206: “The majority of current glacial reduction in the WAP is apparently happening in those areas, and it would seem the Ronne and its status would be more important to the WAP than the Ross Shelf, which, as I pointed out, is a thousand kilometers from the Ronne and the Weddell sea … and a thousand kilometers from the base of the WAP.”

    I guess we were talking past each other then. Your analysis of the WAP seems reasonable. The WAP certainly is being effected by the breakup of Larsen B — as well as by general warming. I don’t know how much land ice is contained in the WAP. If it disintegrates is this likely to raise the sea level sufficiently to dislodge the West Antarctic ice?

    ======================

    Actually, my query was more along the lines of wanting a bit of clarification in relation to what I’ve heard of what is occuring there in relation to the geographic references re the distance of the Ross Shelf from the WAP, as well as its location well within the Antarctic circle as opposed to the WAPs more northerly position (It is the only part of the continent that pokes outside of the Antarctice circle.).

    Regarding your closing question, not sure.

    Recall reading somewhere – maybe here – that as the sea level rises and the leading edges of glaciers retreat to the shoreline that seawater will likely seap under the glaciers, floating them to some degree and speeding up their flow. I believe this was pertaining to Greenland, though obviously this would apply to Antarctica, as well, speeding up the already increased flow of the glaciers on the WAP from the loss of shelf ice.

    The WAP is obviously the most likely to go first, as we’re already seeing:

    http://www.realclimate.org/index.php/archives/2006/03/significant-warming-of-the-antarctic-winter-troposphere/

    http://www.realclimate.org/index.php/archives/2005/04/retreating-glacier-fronts-on-the-antarctic-peninsula-over-the-past-half-century/

    See also:

    http://www.giss.nasa.gov/research/news/20041006/

    I believe the Ross and Ronne are both a lot more stable than Larsen and the other shelves actually butted up against the actual WAP (of course, this may be more a case of stability by comparison, and not by historical norms.) As for West Antarctica proper, I really do no know. But others have commented that the entire continent is showing increasing evidence of warming, so I do not doubt something more dramatic may be happening there, as well, which was why I was curious about your reference to the Ross.

    Relating to the larger, inland sections, there was an interesting, but perhaps outdated at this point, blurb in American Scientist a few years back, discussing the stability of that inland ice sheet in Greenland compared to the coastal regions:

    =========

    Greenland or Whiteland?
    David Schneider

    According to most experts, global warming will lead to some worrisome changes in the not-too-distant future. One that is expected to become quite troubling, at least for coastal residents, is rising sea level. The latest assessment of the Intergovernmental Panel on Climate Change, for example, suggests that the world may see anywhere from 11 to 77 centimeters’ rise in sea level before the century runs out. One of the several sources for all this water, the panel’s scientists concluded, will be the partial loss of the Greenland ice sheet. That view seems quite consistent with recent news reports of Greenland’s slushiness, 2002 having been a record year for summer melting there. But a new study suggests that the Greenland ice sheet may, in fact, grow as the climate warms over the next several decades, which would modestly diminish the rate at which the oceans are expected to rise.

    http://www.americanscientist.org/template/AssetDetail/assetid/26024
    =============

    See also more current info here:

    http://www.realclimate.org/index.php/archives/2007/07/making-sense-of-greenlands-ice/

    Comment by J.S. McIntyre — 21 Aug 2007 @ 9:46 AM

  210. Re #209: “I believe the Ross and Ronne are both a lot more stable than Larsen and the other shelves actually butted up against the actual WAP (of course, this may be more a case of stability by comparison, and not by historical norms.) As for West Antarctica proper, I really do no know. But others have commented that the entire continent is showing increasing evidence of warming, so I do not doubt something more dramatic may be happening there, as well, which was why I was curious about your reference to the Ross.”

    The Larsen B breakup was caused by summer ice surface melt forming pools which flowed into the sheet and refroze (splitting the sheet). As long as summer temperatures over the Ross and Ronne remain largely below freezing a sudden disintegration like Larsen B isn’t very likely. (Wouldn’t know about other forms of breakup…)

    I’ve read somewhere that both Greenland and East Antarctica are largely mountain bound; which is a strong stabilizing influence — but West Antarctica doesn’t have mountains between the major sheet and the sea.

    Aside from jutting outside the polar region, I don’t think the WAP has bounding mountains — but rather a mountain spine. The combination would make it particularly unstable.

    Comment by Sphere — 21 Aug 2007 @ 5:00 PM

  211. NASA have found melting of the Ross Ice sheet. See:
    http://www.nasa.gov/vision/earth/lookingatearth/arctic-20070515.html
    and
    http://alaskareport.com/do77811_antarctica.htm

    That is based on conditions over two years ago. It would be interesting to see what happened last year and next.

    Comment by Alastair McDonald — 21 Aug 2007 @ 5:55 PM

  212. Re #211: “That is based on conditions over two years ago. It would be interesting to see what happened last year and next.”

    A brief excursion into Googleland came up with nothing new…

    There’s got to be primary data out there somewhere, but I’ve no idea what the magic incantation would be.

    Repeated ice melt along Ross’s inland boundary would be “big news.”
    (Of course, no one else would even understand that it was news at all….)

    That melt picture from 2005 has me wondering something…why would it melt at the inland boundary before further north?

    Comment by Sphere — 21 Aug 2007 @ 6:45 PM

  213. Steele — I respectufully suggest you go to the top of the page and click on

    Start Here.

    Comment by David B. Benson — 21 Aug 2007 @ 7:42 PM

  214. Cryosphere Today is basically reporting “screw you”. There’s no hint of recovery before the normal end of melt — in fact, it looks like leveling may even be late. http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/recent365.anom.region.1.html

    Is there any reason to think this is not the butterfly catastrophe? (A butterfly catastrophe is a topological notion — not to be confused with the notion of a butterfly in China effecting weather in New York. Basically, it’s when the equipotential for an event surface curves under and there is no meta-stable state. There is then no choice but to leave the potential surface and fall to the underlying equipotential surface — a catastrophe.)

    Comment by Sphere — 21 Aug 2007 @ 7:48 PM

  215. Re #212 Sphere,

    I am fairly sure that the melting at the base of the Transantarctic Mountains is due to katabatic winds. Normally these are cold winds, but they can be warm as well. See the Bora Wind shown as the last diagram on this web page: http://snrs.unl.edu/amet498/wenzl/katabatic.html

    Comment by Alastair McDonald — 22 Aug 2007 @ 4:40 AM

  216. Melting is not slowing as it should, in fact, it seems to be speeding. I also have the impression that the melting season will be longer than other years. There’s a lot of heat in that water/air, lots of inertia.

    Comment by John P. — 22 Aug 2007 @ 5:23 AM

  217. Re #215 I should have said the melting at the base of the Transantarctic Mountains is probably caused by katabatic Foehn winds. See: http://en.wikipedia.org/wiki/F%C3%B6hn_wind

    Comment by Alastair McDonald — 22 Aug 2007 @ 6:28 AM

  218. RE # 216

    John P.,

    The Chapman graph indicates a melt back of 1.75 million sq. mi since the mid-May high point.

    Using the Rothrock estimate of diminished ice thickness from 1958 3.1 m average to 1.8 m average in the 1990s, a very rough calculation is about 8.2 billion tons of ice melt.

    Thinning of the Arctic Sea-Ice Cover
    D.A. Rothrock, Y. Yu, and G.A. Maykut
    University of Washington, Seattle, Washington

    http://psc.apl.washington.edu/thinning/Rothrock_Thinn.pdf

    Converting ice to liquid at 32 deg F requires 288,000 Btu/ton. Thus, the heat of fusion to change states was about 2.4 trillion Btu since May.

    The average thickness continues to decrease as multi-year ice is replaced by new ice each freeze season.

    Assuming the heat transported to the Arctic and generated in the Arctic by solar incidence will not diminish considerably during the next twelve months, one could assume next year melt back will be greater than this year because less heat of fusion will be required to melt the new ice and the uncommitted heat will be available to melt more multi-year ice.

    I am not a scientist (as you can tell) but this looks to me like the Artic sea ice entering a tipping point phase.

    Comment by John L. McCormick — 22 Aug 2007 @ 9:36 AM

  219. Since this post went up, the anomaly in the Antarctic on CT has dropped to (nominally) zero, and in the Arctic has dropped to around -2.25M km2. I was wondering if this is a record for the global sea ice anomaly? Anyone know? Also, I can’t find anything on why sea ice seems to have stopped growing in the Antarctic, about three or four weeks ealier than last year…

    Regards,

    Comment by Fergus Brown — 22 Aug 2007 @ 10:36 AM

  220. Re #218 The concept of “tipping point” does not seem to be well understood. It occurs in a dynamical system when the forcings from the positive feedbacks exceed those from the negative feedbacks. Normally a dynamic system will be stable with the negative feedbacks dominating. Think of a ball sitting in a saucer. It does not move, because it will have to rise up the side of the saucer and the negative feedback from gravity keeps it steady.

    If we could make the saucer flat, then turn it into a dome, the ball would then run away down the side of the dome. The tipping point is when the change from flat to dome happens, and when gravity changes from being a negative to positive feedback.

    The tipping point for the Arctic ice happened many years ago when the ice first started to melt. The ice-albedo effect now dominates the behavior of the ice and that is the positive feedback which has taken over. Before the ice disappears there is also a point of no return, which is reached after the tipping point. It seems that we are now past that event too.

    It seems obvious to me that we have already passed teh tipping point for the destrucyion of the Greenland ice sheet, but not neccessarily the point of no return. However, when the Arctic Ice has melted, then by your estimate there will be an additional 2.4 trillion Btu entering the Arctic Ocean each year with no ice to melt. With that additional heat in the Arctic region it seems clear to me that it will not be long before the Greenland Ice sheet also passes it point of no return.

    Comment by Alastair McDonald — 22 Aug 2007 @ 11:21 AM

  221. I just wanted to note that there is more Arctic sea ice out there than is being recorded by the Cryosphere Today or the NSIDC.

    Here is a Visible satellite picture of the Beaufort Sea from yesterday from the Terra/Modis satellite. This area is supposed to be ice-free according to the software-generated pictures from the NSIDC and the Cryosphere (I assume you believe your own eyes.)

    http://rapidfire.sci.gsfc.nasa.gov/realtime/single.php?2007233/crefl1_143.A2007233221500-2007233222001.4km.jpg

    Here is the same picture in false-color where the ice is coded to be Red (note the orange color is cloud-cover.)

    http://rapidfire.sci.gsfc.nasa.gov/realtime/single.php?2007233/crefl1_367.A2007233221500-2007233222001.4km.jpg

    Comment by John Wegner — 22 Aug 2007 @ 1:41 PM

  222. Re #220: “If we could make the saucer flat, then turn it into a dome, the ball would then run away down the side of the dome. The tipping point is when the change from flat to dome happens, and when gravity changes from being a negative to positive feedback.”

    People use the term tipping point in different ways, although I tend to use your definition. What he is calling a tipping point would be akin to the point where the ball falls off the plate — what I’d call a catastrophe.

    Falling off the plate is in a sense a tipping point — the equipotential surface at the edge of the plate is such that there is no meta-stable surface available and the ball tips off the plate.

    Comment by Sphere — 22 Aug 2007 @ 5:05 PM

  223. John, that image seems to me to match up reasonably well with the map, once I rotate one to match the other. Big gap north of Alaska; ice along the shoreline where Canada extends further north.

    “Sea ice extent is particularly low in the East Siberian side of the Arctic (the Chukchi and East Siberian Seas) and the Beaufort Sea north of Alaska. Ice in the Canadian Archipelago is also quite low. Along the Atlantic side of the Arctic Ocean, sea ice extent is not as strikingly low, but is still less than normal.” says the map caption.

    Sea ice is defined as including areas of broken floating ice and water. The pixel size on the map is larger than the small floating ice chunks; they talk about that issue at NSDIC.

    Comment by Hank Roberts — 22 Aug 2007 @ 5:22 PM

  224. Alastair says: “The tipping point for the Arctic ice happened many years ago when the ice first started to melt. The ice-albedo effect now dominates the behavior of the ice and that is the positive feedback which has taken over.”

    Things seem to be far more complicated than that. Take a look at Arctic Sea Ice decline in the 21st Century, Bitz, RC, Jan 2007

    “As illustrated in Fig 1, the sea ice retreat accelerates during the 21st century as the ice decays and more sunlight is absorbed by the ocean (the positive ice-albedo feedback). Increasing ocean heat transport under the sea ice adds to the melt back. The retreat appears abrupt when natural variability in the ocean heat transport into the Arctic Ocean is anomalously high. We did not find clear evidence of a threshold, which can be difficult to identify given the variability and complexity of the climate system. Therefore we can neither verify or rule-out the existence of a tipping point. Regardless, the rapid declines seen in our runs are a serious concern.

    There’s also the role of the atmosphere in the poleward heat transport, as well as the loss-of-insulation effect, which allows the Arctic Ocean to exchange heat with the atmosphere. In the winter, open leads result in more ocean-to-atmosphere heat transfer, and in the summer the effect is in the same direction. See http://www.sciencemag.org/cgi/content/full/315/5818/1533

    Estimates are that most (~98%) of the energy supplied annually to the Arctic system is due to atmospheric poleward heat transport. We could speculate that the warming atmosphere causes the sea ice to thin in the Arctic, resulting in increased heat transfer to the atmosphere from the ocean and a resultant increase in the rate of sea ice melting – a stable feedback loop which is amplified by the ice-albedo feedback effect in the summertime. Thinning sea ice is also more susceptible to being piled up by the wind, exposing more of the ocean to the atmosphere – a global warming-induced amplification of the ‘intrinsic natural variabilty’ in the Arctic.

    Oddly enough, Roger Pielke Sr. claims that “Thus, it is regional warming, not “global warming” that appears to be the reason for this melting (Indeed, if it were global warming, we should see a similar reduction in Antarctic sea ice coverage, which, however, is not occurring).” (Aug 10 2007 post)

    Anyone see any flaws in Dr. Pielke’s reasoning?

    Comment by Ike Solem — 22 Aug 2007 @ 7:25 PM

  225. Yikes!
    http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/current.area.jpg
    When you run along the annual minima on this chart, we see we have another hockey-stick happening right before our eyes!

    Comment by Nigel Williams — 22 Aug 2007 @ 7:50 PM

  226. #220 Alastair, I agree with the tipping point scenario, but I don’t think it will happen as easily as within a laboratory experiment. The entire meteorological dynamics have changed since there is a present “colder sector” over the Arctic Ocean remaining ice, contrasted to when not long ago the ice was spread more evenly around the North Pole. This affects what we were use to weatherwise. So far I am seeing a more persistent low over Hudson Bay, and of course everyone has heard about the rain. There is a North Pole centered wobble in met systems rather than a Pole centered merry go round of planetary waves. That ultimately garrantees a summer time cooler wetter zone (Eastern North America, Western Europe) as opposed to a dryer hotter zone (the rest of the Northern Hemisphere). I still would like to see some models show what might happen, longer term with this ice assymetry at the North Pole. Moisture gained ultimately affects global temperatures (seasonal short term), so the run away effect may be not transpire exactly as expected, as such contrarians will still be fooled or try to fool the lay in believing that GW is bunk, despite the overwelming message given by the missing ice at the Pole.

    Comment by wayne davidson — 22 Aug 2007 @ 10:36 PM

  227. 223 Hank, Looking at single sat pics of ice often misleads, clouds and contrast settings fool many experts, its wiser to look at the Cryosphere today animation:

    http://arctic.atmos.uiuc.edu/cryosphere/sea.ice.movie.2007.mov

    Perhaps Mr Wegner and Nigel will apppreciate that the ice moves constantly, even during the dark winter, especially more during summer. The melt down in June was something really rare (“never seen anything like this” is an understatement) I would like to thank the Cryosphere Today guys for their excellent work as well.

    Comment by wayne davidson — 22 Aug 2007 @ 10:48 PM

  228. A new update is posted at NSIDC. http://nsidc.org/news/press/2007_seaiceminimum/20070810_index.html
    There is a wonderful animation showing icemovement and seasonal depositions. Apperently wind and drift is a heavy influence, ice transported south melts quicker. Packed ice is more resisting.
    How is the wheater pattern of the arctic changing by the now open sea? I read that this summer has seen unusual high preassure sunny skies. Is this just wheater or is it influenced by reduced ice? Will drift increase when the caps extent is reduced?

    Comment by horrified observer — 23 Aug 2007 @ 3:05 AM

  229. NSIDC wrote:

    22 August 2007

    Overview of current sea ice conditions

    Sea ice extent continues to decline; it is currently tracking at 4.92 million square kilometers (1.89 million square miles), below the 2005 record absolute minimum of 5.32 million square kilometers (2.05 million square miles

    http://nsidc.org/news/press/2007_seaiceminimum/20070810_index.html

    If the 22 Aug 2007 had been the minimum sea ice extent for the year, relative to 2005, we could “expect” there to be sea ice throughout the summer up to 2031. But if we kept losing it at the same rate until the end of September, relative to 2005, with the minima for the year being 4.6 km^2 relative to the 2005 figure of 5.32, the same rough calculation would tell us 2018.

    Comment by Timothy Chase — 23 Aug 2007 @ 3:38 PM

  230. Re #229: “If the 22 Aug 2007 had been the minimum sea ice extent for the year, relative to 2005, we could “expect” there to be sea ice throughout the summer up to 2031. But if we kept losing it at the same rate until the end of September, relative to 2005, with the minima for the year being 4.6 km^2 relative to the 2005 figure of 5.32, the same rough calculation would tell us 2018.”

    And if all the multi-year ice is flushed out through the Greenland Sea this winter then what?

    Comment by Sphere — 23 Aug 2007 @ 7:51 PM

  231. Re #228: As Wayne Davidson noted, this is an unusual year. Since the present behavior hasn’t been modeled, I don’t think the experts will hazard a serious guess until they see what happens over the next couple of years. Of course, at this point a complete summer collapse over a very short time cannot be ruled out.

    Re #229: IMHO that rate is much too conservative. Since we’re losing about .06 million km^2/day just now, in no more than another week we’ll probably be waving bye-bye to 4.6 million km^2 through the rear-view mirror. I’ll be bold and guess that we’ll hit about 4.0 this year. I base that on seeing how much ice loss there was in 2005 after the slope of the extent graph had a similar appearance to the present one, and assuming that the melt season won’t go much later this year. But of course this is anybody’s guess. Also note that the extent metric (basically the area within the intact pack ice perimeter) will go off the rails when there ceases to be enough intact ice to define a perimeter.

    Re #230: There’s not much multi-year ice left now. AIUI a lot of that will probably persist in place since it’s caught up by the Canadian islands and Greenland.

    Comment by Steve Bloom — 23 Aug 2007 @ 9:17 PM

  232. Beware the Dark Side, Luke! Er, I mean, don’t let RP Sr. confuse you, Ike. If you read down that thread a bit you’ll notice that RC co-author William Connolley made a correction that RP Sr. was forced to accept. William’s day job is as a sea ice modeler for the British Antarctic Survey, meaning that he’s rather more qualified than RP Sr. in this subject area. But in any case RP Sr.’s reasoning is semantic nonsense since there’s no such thing as a global forcing that has even effects across two or more regions. He has a bad habit of trying to shoehorn his memes into facts that won’t fit them.

    Comment by Steve Bloom — 23 Aug 2007 @ 10:14 PM

  233. Re #224: Just to add that since RP Sr. was unable to accept William’s correction with any grace, he added this little snark: “The increase in sea ice areal coverage in Antarctica is not predicted.” It’s true as far as it goes, but of course RP Sr. knows that the trend is sufficiently slight that it isn’t statistically significant, i.e. it doesn’t mean anything. The problem is that since RP Sr. is a senior climate scientist with a more-or-less respected lifetime of work behind him, the uninformed reader will tend to be taken in by assertions of that sort. There’s a very strange pathology going on over there, and RP Sr.’s embrace of the “audit” crowd is of a piece with it.

    Comment by Steve Bloom — 23 Aug 2007 @ 10:25 PM

  234. Its incredible watching the spread of 60 percent ice (red) on the UIUC images heading for the pole.

    http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/arctic.jpg

    It even looks like the pole itself is now at 80 percent, not 100 percent ice concentration, so even there we are looking at melting ice blocks floating in a warming sea, not a nice solid reassuring sheet of ice with a comforting layer of cold air sitting on top.

    Hello New York! Is anybody standing outside the UN every lunch time with hand-outs of these pix and charts?

    Comment by Nigel Williams — 23 Aug 2007 @ 10:47 PM

  235. This AMS presentation from last year by Wieslaw Maslowski (the U.S. Navy’s sea ice modeler) is worth a look. On page six he notes “If this trend persists for another 10 years (and it has through 2005) the Arctic Ocean could be icefree in summer!” While no other sea ice expert has been willing to stick their neck out quite this far, my understanding is that many of them thought Maslowski could be right even before this summer’s abrupt change.

    Comment by Steve Bloom — 23 Aug 2007 @ 11:53 PM

  236. re 232. The spread of broken ice is more clear at this site http://iup.physik.uni-bremen.de:8084/amsr/arctic_AMSRE_nic.png.
    Flyers outside UN would be good. I am horrified by this development and shocked that it is not front page news. Albedo flip right now and a clear message that IPCC and politicians are way off. Do we still have 1000 days?

    Comment by horrified observer — 23 Aug 2007 @ 11:54 PM

  237. Would be interesting to see a stat on the reduction of multi year ice since 1979.

    Clearly the one year ice does not have he resilience of the multi-year, and it appears we are loosing the multi-year rather rapidly.

    I think #231 is probably correct, would help to have rate of multi-year ice reduction data to project when the ice cap will be gone in summer.

    Keep up the great work.

    Comment by Jon Kessler — 24 Aug 2007 @ 12:43 AM

  238. Re:232

    It hasn’t been solid for a while. You can even swim there:

    swiming at north pole

    Comment by John P. — 24 Aug 2007 @ 3:03 AM

  239. Re 232: “It even looks like the pole itself is now at 80 percent, not 100 percent ice concentration, so even there we are looking at melting ice blocks floating in a warming sea, not a nice solid reassuring sheet of ice with a comforting layer of cold air sitting on top.”

    Speaking of a warming sea: http://sharaku.eorc.jaxa.jp/cgi-bin/amsr/polar_sst/polar_sst.cgi?lang=e

    It’s going to take some time this Fall to dissipate 5 extra degrees.

    Comment by Sphere — 24 Aug 2007 @ 5:08 AM

  240. I wonder how the disappearance of Artic Sea Ice will effect the Greenland Icecap, logically one would assume that the open ocean water will absorb a great deal more heat than the artic ice did, that this would lead to a relatively warm sea surrounding Greenland which would accelerate it’s the loss of land ice.

    Also, when tipping points are discussed, isn’t there also the issue of methane that’s been trapped in Artic Tundra now being released as that Tundra thaws. Seems like this will also increase warming.

    Comment by Vince — 24 Aug 2007 @ 1:59 PM

  241. I have been watching the temperatures in places like Alert (most northern weather station) at 82 north. It 7 Celsius above. The sun is getting very low this time of year, and it should be around -4 to -5. All August it only dropped one degree below freezing for several hours a couple of times.

    Looking at the cryosphere, I keep expecting the ice lost graph to start levelling out, but it remains in deep decline. The north pole may melt out or reduce to loose (1/10 – 3/10) pack ice yet before the end of the melt season.

    Comment by Larry — 24 Aug 2007 @ 3:33 PM

  242. Re #240: “I wonder how the disappearance of Arctic Sea Ice will effect the Greenland Icecap, logically one would assume that the open ocean water will absorb a great deal more heat than the artic ice did, that this would lead to a relatively warm sea surrounding Greenland which would accelerate it’s the loss of land ice.”

    It’s a little more complicated because the Greenland plateau rises well above sea level. The warm water will cause warm air carrying more water vapor; which will fall as snow in the highlands of Greenland. Short-term it’s anybody’s guess whether the combination will result in more water sequestered in the Greenland ice cap or less. Of course, with continued warming the water will fall as rain rather than as snow — bye bye ice.

    “Also, when tipping points are discussed, isn’t there also the issue of methane that’s been trapped in Arctic Tundra now being released as that Tundra thaws. Seems like this will also increase warming.”

    Google isn’t finding much new on the subject. This is from 2005: http://www.iarc.uaf.edu/highlights/methane/index.php

    Comment by Sphere — 24 Aug 2007 @ 3:54 PM

  243. The only “normal” Arctic sea ice area is the Greenland sea. At first I thought it was because this sea is leeward of Greenland, but more and more I think it’s because the Arctic Basin is draining into it as fast as it can. It’s a bit hard to interpret the surface windfields ( http://www.cdc.noaa.gov/map/images/fnl/sfcwnd_30b.fnl.html ), but it looks like they’ve been blowing that way fairly consistently. Anyone know a good picture of near-real-time Arctic currents? (Something like this one for the Gulf Stream: http://rads.tudelft.nl/gulfstream/ )

    Comment by Sphere — 24 Aug 2007 @ 6:25 PM

  244. Re 239: Interesting SST imagery. While we were watching the Atlantic, the Pacific performed these tricks.

    Comment by Pekka Kostamo — 25 Aug 2007 @ 7:07 AM

  245. It looks like that the only reason that tongue of sea ice is lingering towards Siberia is because a current or wind flow is heaping it up against the Severnaya Zemlya islands.
    http://en.wikipedia.org/wiki/Severnaya_Zemlya

    I imagine that as soon as that blows through the Siberian sea route will be open, and it will be hard to close.

    It looks like we have at least another month to go before any serious freezing will take hold,
    http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/current.365.jpg

    so there is plenty of time for mother nature to shake us off her apron, eh!

    I take it that all this thaw is now well outside any models, and so all we can do is watch as the flip flops. With every crack in the ice, the wetted surface area increases, and as the warmer water pushes against the pack the melting runs faster… exponentially, I guess.
    http://iridl.ldeo.columbia.edu/SOURCES/.NOAA/.NCEP/.EMC/.CMB/.GLOBAL/.Reyn_SmithOIv2/.weekly/T/2454328/VALUE/X/20/380/RANGEEDGES/.ssta/

    I note that the north pole webcams havent broadcast any images for the last 3 weeks.
    http://www.arctic.noaa.gov/gallery_np.html

    Presumably they are now sitting with that plaque the Russians placed at the pole – 4000m deep. Not a good look.

    Comment by Nigel Williams — 25 Aug 2007 @ 7:51 PM

  246. Lets face the facts. Since the last ice age 10,000 years ago the ice has been melting. Sure lets face it
    burning fossel fuels does not help. If you look at the ice melts from 10,000 years ago to now.
    I can see why there is such a large ice melt in 2007 and so on in the years to come, there is no ice compared to 10,000 years ago. Maybe when all the ice melts there will be an astroid strike and put the world into another big ice age, just a thought!

    Comment by Darryl — 25 Aug 2007 @ 8:00 PM

  247. Darryl, are you aware of the fact that everything we know about glaciation/deglaciation cycles indicate that we should be cooling by now?

    Comment by Philippe Chantreau — 25 Aug 2007 @ 9:05 PM

  248. But Darryl, what you believe about the time sequence is not the fact commonly understood to be true.

    You claim to be facing facts —- you should point to them so others can tell which direction you’re looking.
    What source do you believe, that you trust for what you consider this fact?

    The peak temperature was — typical of the pattern — right after the ice age ended, some ten thousand years ago.

    The best facts we have are from the scientific work, and those show there has been the typical slow cooling thereafter — until human influences outweiged it, perhaps as early as several thousand years ago, if you follow Ruddiman’s work.

    Comment by Hank Roberts — 25 Aug 2007 @ 9:44 PM

  249. Nigel Williams (#245) wrote:

    I note that the north pole webcams havent broadcast any images for the last 3 weeks.
    http://www.arctic.noaa.gov/gallery_np.html

    The sea ice in the Arctic is still dropping fast judging from the updates at Cryosphere Today today, but we are still getting images from the north pole. Looks like something out of Disney’s 101 Dalmatians, but the camera is still there:

    http://www.arctic.noaa.gov/latest/noaa4.jpg

    Note: at the time of this posting, the date was saying Aug 25, 2007 and time 20:52 – but undoubtedly subject to change – judging from the path…

    Comment by Timothy Chase — 25 Aug 2007 @ 10:19 PM

  250. Re: 245

    Actually the North Pole Web Cam has a replacment Cam on the ship Polarstern. The cam was transmitting on the ship when it was heading for the north pole earlier this month, but headed south in early august for some reason. It started back north a few days ago, and they resumed the pictures. The ship is now at 86 north according to the polarstern web site. Looks like about 8/10 to 9/10 ice at this point. Not a good place to drop a camera off.

    The old web cams have drifted from 89 north in april to 86 north in august. Those original cameras are closer to the thick ice that is outflowing from greenland (see weather data page off of the north pole web cam page). I don’t think cam 1 or 2 has sunk yet, but it may in the next few months as it head south. No pictures from the third however (should had been one on August 17, based on faulty data transmission for camera 1 and 2), and no weather data since the 13th, however people may be on vacation.

    It would be nice if they update the site more often, rather than forcing us to deduct it from data from several differnt web sites; considering its the International Polar Year and also the year of the tipping point. Nice Coinicidence.

    Comment by Larry — 26 Aug 2007 @ 6:19 AM

  251. Tired of waiting for NSIDC to report on their ice data? Get Google Earth and pick up your KML feeds from: http://nsidc.org/data/google_earth/

    Comment by Sphere — 26 Aug 2007 @ 1:40 PM

  252. I see only one thing to say in view of this year’s ice extent: yikes!

    Comment by Philippe Chantreau — 26 Aug 2007 @ 4:06 PM

  253. The current record retreat in Arctic ice during the summer melt comes with reports of another endangered specie: cultural icon Santa Claus will relocate toy manufacturing and distribution operations to the Antarctic continent, along with his fleet of pole-adapted aeronautical reindeer. Due to increased average shipping distances, the traditional gift-giving will be required to be rescheduled to Boxing Day.

    A tipping point, indeed.

    Comment by Jerry — 26 Aug 2007 @ 9:56 PM

  254. Ah oui monsieur Phillippe! But who is it that you are saying Yikes too? I admit Ive only sent one Yikes email to a politician this week about this, which is slack of me I know. Ill try and do better!

    If I sent a YikesMail every time I posted here, I may get a better result!

    Comment by Nigel Williams — 26 Aug 2007 @ 11:14 PM

  255. I limit my Yikes e-mailing to politicians due to my immigration status, which, however legal, does not allow me to vote. I guess that perhaps I should send more yikesing, since all the mail they send me to court my non-vote indicates that they probably don’t know anyway…

    Comment by Philippe Chantreau — 27 Aug 2007 @ 12:24 AM

  256. Does anynody have a link on the met office Polar ice long term animation presentation? Once seen on their main page….

    Comment by wayne davidson — 27 Aug 2007 @ 4:45 PM

  257. “Yikes” would imply some sort of deep seated surprise. The only surprise here is that weather is a chaotic system and there’s no way to predict when conditions will come together and force a systematic state change. The presence of a catastrophic boundary has been obvious for years — and the only question has been when it would be encountered.

    I’m not sure we have encountered that boundary, though it sure looks likely. We wait to see what sort of recovery the ice makes this winter. If the recovery’s more than a half million below previous years then barring several major explosive eruptions the ice cap is history. If the recovery is fairly complete then there will probably be several years of vacillation first. (Climatologists
    need to spend more time studying ecological collapse and less time studying physics. This is a chaotic system they are trying to model, not billiard balls.)

    Comment by Sphere — 27 Aug 2007 @ 5:37 PM

  258. Weather is chaotic; climate isn’t.
    http://illconsidered.blogspot.com/2006/03/chaotic-systems-are-not-predictable.html

    Comment by Hank Roberts — 27 Aug 2007 @ 5:58 PM

  259. Re #257 [The only surprise here is that weather is a chaotic system and there’s no way to predict when conditions will come together and force a systematic state change.]

    Actually it’s not a chaotic system.
    A standard definition of chaos is given in

    Davaney, R., Introduction to Chaotic Dynamical Systems 2nd Ed,
    Addison-Wesley, 1989:

    A function f:R -> R exhibits deterministic chaos if it
    satisfies three properties:

    1) sensitivity to initial conditions arbitrarily close to every
    point x, there is a point y with f^n(x) and f^n(y) iterating far apart.
    2) dense periodic points arbitrarily close to every point x, there is a
    point y with f^m(y) = y for some m.
    3) mixing for every pair of intervals I and J, for some k f^k(J)
    and I overlap.

    This means that if “chaos” is used in the technical sense, a chaotic system must be closed (and deterministic), while Earth’s climatic system is thermodynamically open. A better term in this case is a “dissipative system”: one that feeds off a low-entropy source of energy (in this case the sun) to self-organise, giving off higher-entropy energy in the process. Such systems do indeed often show the kind of “systematic state change” you talk about. However, the general direction of that change in response to certain kinds of external influence (in this case adding greenhouse gases) can be quite predictable, while the exact path taken may not be.

    Comment by Nick Gotts — 27 Aug 2007 @ 6:16 PM

  260. Re 258″ “Weather is chaotic; climate isn’t.”

    Weather is chaotic, and therefore climate has chaotic boundary conditions. That is, you can’t predict when a catastrophe will happen.

    Comment by Sphere — 27 Aug 2007 @ 7:36 PM

  261. Re 259: “Introduction to Chaotic Dynamical Systems”

    Did I say anything about thermodynamics, or any sort of dynamics? I’m a programmer. Please explain in terms if information lost while transmitting a message.

    Thus, closure only means something to me as a mathematical property, and thermodynamics is nothing more than a nifty description of our current lack of understanding. (There is no such thing as a “closed system” as you are describing them, and therefore no ‘real’ reason to consider them. Your ‘definition’ has no content.)

    Now… The sensitivity of weather to minor perturbations is such that there is no determination of the result from some supposed initial conditions, but there are periodic behaviors. Weather systems behave chaotically, and the outline of their behavior can be fairly modeled as you have stated. I agree that the general shape of climate can be predictable — but not timings. (I don’t know if climate is properly chaotic or not. The timeframe for deciding this is much longer than the time I expect to be alive.)

    Comment by Sphere — 27 Aug 2007 @ 7:56 PM

  262. I would like to know, if there exist any studies on the impact of ice-free Arctic into the climate of the Northern Hemisphere. Pointers appreciated!

    Is some research group modelling ice-free North Pole? Is there reasearch going on incorporating that condition into the global climate models?

    My intuitive feeling is that the melten Arctic will significantly increase the number of extreme weather conditions.

    Comment by Petro — 27 Aug 2007 @ 8:22 PM

  263. And just how accurate are current passive microwave methods, in terms of their ability to successfully detect and characterize sea ice? (This question is neither meant to be naive, nor, rhetorical, it is meant to provoke a serious discussion informed by science and engineering considerations).

    Comment by SteveSadlov — 27 Aug 2007 @ 9:24 PM

  264. RE: #47 – For geopolitical or military reasons, would one or more great powers ever consider purposely dissipating sea ice? Of course they would. To think otherwise is to be in denial of human nature. As ugly as that may be.

    Comment by SteveSadlov — 27 Aug 2007 @ 9:30 PM

  265. The ice by Severnaya Zemlya is thinning noticeably over the last few days, with what looks like leads opening between the islands closer to the coast.
    http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/arctic.jpg

    It’s looking a bit cloudy over some of the exposed ocean, but there is still room for the sun to shine through.
    http://en.allmetsat.com/images/composite_ssec_c.php

    It’s a tense moment, eh!
    http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/current.365.jpg

    No net change in extent over the last day or so – but we still have to make it through the September null before it turns around.

    What will tomorrow bring? A pause, or a dive?

    Comment by Nigel Williams — 28 Aug 2007 @ 1:00 AM

  266. RE #261 [(There is no such thing as a “closed system” as you are describing them, and therefore no ‘real’ reason to consider them. Your ‘definition’ has no content.)

    Now… The sensitivity of weather to minor perturbations is such that there is no determination of the result from some supposed initial conditions, but there are periodic behaviors. Weather systems behave chaotically]

    If the definition I quoted had no content, you wouldn’t be able to say that there were no such things. Agreed, there are none – but some systems, e.g. a double pendulum, are near enough closed to be usefully treated as chaotic systems in the sense of the definition I quoted. Weather and climate are not. What do you mean by “Weather systems behave chaotically”? Just sensitive dependence on initial conditions together with periodic behaviours?

    Comment by Nick Gotts — 28 Aug 2007 @ 5:15 AM

  267. [[There is no such thing as a “closed system” as you are describing them, and therefore no ‘real’ reason to consider them. ]]

    You just debunked reductionist science in general.

    Comment by Barton Paul Levenson — 28 Aug 2007 @ 5:45 AM

  268. Re 266: “Just sensitive dependence on initial conditions together with periodic behaviours?”

    First, there is no such thing as initial conditions. A chaotic system is one which can respond differently at different times to the same stimulus. The Natural Number group is not chaotic, a cat is chaotic. It may be that all natural systems are chaotic, though I am not proposing this as a fact.

    While I agree that dynamics can usefully describe the behavior of some chaotic systems, I do not agree that dynamics defines them. (Basically, I disagree with your philosophical stance here that our descriptions have some sort of fundamental meaning.)

    Comment by Sphere — 28 Aug 2007 @ 6:16 AM

  269. Sphere–well, given that climate is defined as the average weather conditions persisting over time, the very idea of predicting events is outside the scope of “climate studies”. Weather does indeed often exhibit characteristics of chaos. Climate has been remarkably stable over the past 10000 years–coincident with the development of human civilization.

    Comment by Ray Ladbury — 28 Aug 2007 @ 7:00 AM

  270. Re #268 [Basically, I disagree with your philosophical stance here that our descriptions have some sort of fundamental meaning.]

    That’s not my philosophical stance. I’m just trying to discover what you mean by “chaotic”. There’s an everyday meaning of this word: without any discernible order, a complete mess. You don’t seem to mean that. There’s a mathematical meaning for it, which I guessed you thought you meant, but which doesn’t fit either weather or climate – hence my original post. You don’t mean that. I’ve suggested a meaning. You don’t mean that. But you won’t say what you do mean. Maybe you don’t know?

    Comment by Nick Gotts — 28 Aug 2007 @ 7:52 AM

  271. Look at the time scale.

    The solar system is chaotic, over the extremely long time scale.
    http://adsabs.harvard.edu/abs/2007DDA….38.1101L

    But Velikovsky is still wrong.

    Comment by Hank Roberts — 28 Aug 2007 @ 9:16 AM

  272. Re 267: “You just debunked reductionist science in general.”

    To the extent one believes there is some sort of Truth and believes in Science as a religion, yes. If one is very careful, and always clear that science never proves anything, but only tends to confirm or tends to deny — no.

    Comment by Sphere — 28 Aug 2007 @ 5:43 PM

  273. Re 270: “There’s a mathematical meaning for it…”

    You provided a thermodynamic meaning, not a mathematical one.

    I’m objecting to your hijacking the word and ignoring the common meaning while asserting this as some sort of ‘real’ meaning. The common meaning of chaotic is “unpredictable, and unexpectable.”

    It’s very common for a certain brand of Scientismist to hijack words and then make claims about other people’s understandings based upon these mis-applied meanings to previously otherwise well defined words. This is what I think you are doing here.

    Given the well established meaning of ‘chaotic’, a chaotic system is one for which you cannot predict a consistent response to a given stimulus. (I would speculate that this always implies the system has internal state…but this is mere speculation.)

    I’m perfectly willing to grant that thermodynamics provides a very useful description of certain chaotic systems. I am not willing to let you (or other Thermodynamic Scientismists) hijack the word chaotic.

    Comment by Sphere — 28 Aug 2007 @ 6:14 PM

  274. Re 271: “The solar system is chaotic, over the extremely long time scale.
    http://adsabs.harvard.edu/abs/2007DDA….38.1101L

    I’m a bit unclear on what the abstract was trying to say, but it seems to me they were saying that the Solar system has dynamic strange attractors. Since our ability to predict orbits decays with distance in time this system at least appears chaotic to us. (Given the bleeding of atmospheres and the like, it’s a pretty safe bet that the Solar system is chaotic period.)

    Comment by Sphere — 28 Aug 2007 @ 6:24 PM

  275. Another week.

    Another million square km.

    The curve seems to be leveling, but no signs of an abrupt bottom like last year. At least not so far. (How low can you go?)

    My turn for a YIKES! The news media has picked this up almost not at all. We’re going to be talking about next spring’s poor recovery before they even notice.

    Comment by Sphere — 28 Aug 2007 @ 6:32 PM

  276. Yes, the sea ice area is 2.99 million kilometers, and the sea ice extent is 4.78 square kilometers as of August 28.

    Which shows that the remaining ice is in bad shape.

    They are now predicting the ice to be gone by 2030, which I consider a very conservative statement.

    If 2007 was the tipping point, then it will be far sooner.

    Comment by Larry — 28 Aug 2007 @ 8:40 PM

  277. Sphere (#275) wrote:

    The curve seems to be leveling, but no signs of an abrupt bottom like last year. At least not so far. (How low can you go?)

    The chart I usually look at doesn’t show it leveling off…

    Northern Hemisphere Sea Ice Anomaly
    http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/current.anom.jpg

    … but this chart shows some leveling off:

    Northern Hemisphere Sea Ice Anomaly Timeseries
    http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/sea.ice.anomaly.timeseries.jpg

    There is a pretty good write-up here:

    The Japan Agency for Marine-Earth Science and Technology (JAMSTEC, led by President Yasuhiro Kato) and the Japan Aerospace Exploration Agency (JAXA, led by President Keiji Tachikawa) cooperatively analyzed oceanic and atmospheric observation data and sea ice data acquired by satellites, and found that the sea ice area in the Arctic Ocean has been decreasing at a much faster pace than expected compared to the previous worst record in the summer of 2005.

    Total Area of Sea Ice in Arctic Ocean Smallest Since Observations Started
    http://presszoom.com/story_139925.html

    Link from the same article, this does a pretty good motion image day-by-day:

    Arctic Sea-Ice Monitor by AMSR-E
    http://www.ijis.iarc.uaf.edu/cgi-bin/seaice-monitor.cgi?lang=e

    Gives you a good sense of how thin the concentration is.

    Comment by Timothy Chase — 28 Aug 2007 @ 8:56 PM

  278. John Wegner, 13 August 2007:
    “I’ve looked at the MODIS satellite images a little closer (and with some places having less cloud cover.) There still isn’t a way through the NorthWest Passage without an icebreaker. Maybe in another week or two.”

    Maybe now John?

    From Cryosphere Today’s latest movie:
    http://members.optusnet.com.au/anon10/CryosphereToday.23.8.07.jpg
    And the Terra/MODIS composite for same day:
    http://neo.sci.gsfc.nasa.gov/RenderData?si=600438&cs=rgb&format=JPEG
    (Yes, it shows a touch more brashy ice than CT resolves.)

    How soon before the North-East Passage opens too (arrow)?

    Comment by Glen Fergus — 28 Aug 2007 @ 9:11 PM

  279. Timothy,

    I think Shere is referring to this graph when he talks about bottoming out. http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/current.365.jpg

    Last year the whole of September was fairly flat, but there is no sign of a flat period starting yet this year.

    Comment by Alastair McDonald — 29 Aug 2007 @ 3:55 AM

  280. … although this one does:
    http://nsidc.org/news/press/2007_seaiceminimum/images/20070828_timeseries.png

    Comment by Alastair McDonald — 29 Aug 2007 @ 3:59 AM

  281. RE #273 [You provided a thermodynamic meaning, not a mathematical one.] You’re just mistaken there: the definition refers only to functions from the real numbers to the real numbers: pure mathematics. Thermodynamics is relevant in deciding where it’s useful to apply the mathematical definition to the physical world: it doesn’t usefully apply to systems where thermodynamic exchange with the external environment is important to the dynamics you’re interested in – like Earth’s climate. However, I’m quite happy now that you’ve said what you mean by “chaotic”.

    Comment by Nick Gotts — 29 Aug 2007 @ 5:43 AM

  282. [[Re 267: “You just debunked reductionist science in general.”
    To the extent one believes there is some sort of Truth and believes in Science as a religion, yes.]]

    You miss my point. You say there’s no reason to study closed systems since closed systems don’t exist in nature. That’s like saying there’s no need to study ideal gases or frictionless surfaces. It’s the statement of a scientific illiterate.

    Comment by Barton Paul Levenson — 29 Aug 2007 @ 6:10 AM

  283. The sea ice concetrations for 2007 versus 2005 for the August 27 NSIDC update are even startling than the ice extent reduction. sea ice update

    Comment by mauri pelto — 29 Aug 2007 @ 8:59 AM

  284. I’ve been busy and popped into NSIDC and Cryosphere today after a while away.

    I posted in #110 on 14/8/07 that it was premature to make projections for coming
    years based on the ice situation as of 14/8/07. I now think that position is much
    less tenable.

    I’ve just seen the state of the perennial ice and ice thickness as implied
    in this graph from NSIDC:
    http://nsidc.org/news/press/2007_seaiceminimum/images/20070828_concentration.png
    (As I now find Mauri Pelto has linked to – but it’s so important it bears repeating)
    Also figure 4, the animated gif on the NSIDC website – the reduction of 5 year (red)
    perennial ice is staggering.

    It really is looking to me like there’s been such an impact on perennial ice that
    this is pretty likely to impact the overall trend. (But I stress I am only an amateur
    reader of climate science.) Like others above I’m now thinking of Hansen’s alarm about
    the rapid nature of ice sheet loss.

    This has left me shaken to the core, an ice free Summer Arctic Ocean before 2020 does
    not sound unreasonable to me right now. :(

    Comment by CobblyWorlds — 29 Aug 2007 @ 3:16 PM

  285. Re: 284: This has left me shaken to the core, an ice free Summer Arctic Ocean before 2020 does
    not sound unreasonable to me right now. :(”

    How about before 2010? (Unless you count glacial outflows.)

    Right now I’d not predict that outright — but if we start next spring’s melt a million km short I think it’s a pretty good bet.

    It’s clear the existing regime has collapsed. The question now is whether there’s going to be several years of wild swings or a direct transition to a new meta-stable state. If the ice doesn’t recover this winter there’ll be little room for a swing — too much excess energy. (Barring explosive volcanism.)

    Comment by Sphere — 29 Aug 2007 @ 5:29 PM

  286. Re 282: “You miss my point. You say there’s no reason to study closed systems since closed systems don’t exist in nature. That’s like saying there’s no need to study ideal gases or frictionless surfaces. It’s the statement of a scientific illiterate.”

    Hmmm…

    Perhaps it would help if you quoted me exactly rather than misrepresent what I said.

    There are no circles either. They are just useful fictions — exactly like ideal gases, frictionless surfaces, and closed systems. Being useful fictions does not make them ‘real’. Any definition which attempts to reify closed systems is a definition with no content — it represents nothing. If chaotic systems can be said to exist then they cannot be properly defined as an instance of something which does not exist — they may, however, be partially modeled by a representation of something which does not exist.

    I think you missed some classes on the experimental method and the philosophy of science, child.

    Comment by Sphere — 29 Aug 2007 @ 5:42 PM

  287. Question on climate models.

    Are there any models out there which have in any way predicted the ice dieback of this summer? They don’t have to have gotten the year right. All that I want to know is if any model has predicted that at some point in the near future there would be a one year anomalous minimum double any preceding year. Are all our models basically meaningless?

    (I’m basically asking if all existing models assume that the underlying numeric formula are unchanging. Are there any which attempt a general systems analysis, with changing dynamics?)

    Comment by Sphere — 29 Aug 2007 @ 6:09 PM

  288. Re #287

    I have been predicting a rapid die back but have not published anything. My ideas are based on a famous book in its time called “Climate through the Ages” by C.E.P. Brooks. Once the ice starts retreating there is a positive feedback which speeds the melt up.

    The problem is that the whole of science is hung up on linear trends. For instance see: http://nsidc.org/news/press/2007_seaiceminimum/images/20070810_SeptTrend.gif

    Plot the ice extent for 2007 on that diagram and you can see that, the rather than the straight line shown, the best fit is a parabola going to zero in a couple of years.

    You can argue about whether the climate is chaotic, but it is a non-linear dynamical system with negative and positive feedbacks. So long as the negative feedbacks dominate you have a stable system such as that over the last 10,000 years. But if the positive feedbacks dominate then you have a rapidly changing system just as we had 10,000 years ago at the end of the Younger Dryas. The positive feedbacks cause the system to runaway until it gets into a new state where the negative feedbacks again dominate. The new state is then stable, and it will sit there for perhaps another 10,000 years.

    But the next rapid change is only a few years/months away!

    Comment by Alastair McDonald — 29 Aug 2007 @ 11:02 PM

  289. “Sphere Says:
    29 August 2007 at 17:29
    Re: 284: This has left me shaken to the core, an ice free Summer Arctic Ocean before 2020 does
    not sound unreasonable to me right now. :(”

    How about before 2010? (Unless you count glacial outflows.)

    Right now I’d not predict that outright — but if we start next spring’s melt a million km short I think it’s a pretty good bet.

    It’s clear the existing regime has collapsed. The question now is whether there’s going to be several years of wild swings or a direct transition to a new meta-stable state. If the ice doesn’t recover this winter there’ll be little room for a swing — too much excess energy. (Barring explosive volcanism.)”

    I agree, another summer season like this and barring an unusual winter freeze season it’s hard to see much ice this time next year! It would seem to require a change from the regime prior to this year’s for the ice to last as long as 2020?

    Comment by Phil. Felton — 29 Aug 2007 @ 11:02 PM

  290. ________Why not 2010?_________

    Firstly I’d rather stick to 30 year periods, but a 30 year period will not do
    this process justice, so the minimum I’ll go for is decadal. However note I
    didn’t say 2027 (2 decades from now) – from my reading that sounds like it could
    be an overshoot – I don’t think it at all reasonable to expect a linear continuation
    of the trend offset downwards by this year’s figures.

    It’s almost Sept 2007, that gives 2 melt seasons after this for the Arctic to be
    ice free. And the actual area, rather than the anomaly doesn’t seem to me to
    support “2010 ice free in September”:
    http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/current.area.jpg
    Bear in mind that what NSIDC observed and I bought attention to in post #110,
    the unlucky combination of circumstances, was just that. It may impact future years,
    but expecting it again and again seems unrealistic.

    An ice free Arctic in 2 melt seasons seems very unlikely to me. But adding on
    another 10 melt seasons and bearing in mind what seems now to be a likelihood
    of non-linear response, 2020 seems feasible.

    If people go around claiming “ice-free summer by 2010″ they’re likely to have gaggles
    of the usual tiresome contrarists squawking about “alarmism”. I don’t think we’ll do
    anything about CO2 emissions, but if I’m wrong (as I hope I am) then more delay and
    ill-informed doubt is not what we need now.

    Comment by CobblyWorlds — 30 Aug 2007 @ 1:27 AM

  291. Alastair, please. That was published last year and there’s an entire thread here at RC about it. “The whole of science” isn’t “hung up on linear trends.” You’re in the mainstream.

    You may be thinking of this thread, which points out that linear extrapolations are more optimistic about sea ice than climate model runs and every model includes some runs that show periods of unusually rapid decline (which get blurred if only the average rather than the extreme cases is looked at). This looks at model runs that look much like this week’s Arctic sea ice.
    http://www.realclimate.org/index.php/archives/2007/01/arctic-sea-ice-decline-in-the-21st-century/#more-391

    Comment by Hank Roberts — 30 Aug 2007 @ 3:47 AM

  292. Even if the ice does recover this winter, it may not mean much, as it takes far less energy to melt freshly created thin first year ice, than it does to melt thick multiyear ice.

    Also of interest, on Cryosphere today, if you look at the ice lost for the individual area, rather than the whole picture, it appears that the high arctic (north pole) area shows that melting has come to an end. Now I expect the areas around the ice edge to continue to melt for a few more weeks until the sea cools down, and also as we get rid of some isolated pockets of ice in the Fox Basin of Canada.

    The North Pole Web Cam #4 on the Polar Sterm has reacehd rougly 89 North. Im not sure if the latest images show melt ponds or open leads that are beginning to skim over with ice. But it appears that the Polarstern is having an easy go at it, getting to the North Pole, looking at the distance they covered each day.

    Comment by Larry — 30 Aug 2007 @ 6:47 AM

  293. Sphere,
    There is a risk that this discussion could descend into sophistry. Weather certainly exhibits characteristics of chaos. Climate deals with long-term averages of weather. It is constrained by the conserved quantities–energy, momentum, angular momentum…. And there is no evidence that for small perturbations of the climate, you get chaotic behavior. Perhaps we need to be careful here in our terminology.
    Also, I would characterize your dismissal of the study of closed systems as a bit rash. While a circle may be merely a useful construct, a Sphere evidently does exist ;-) and can either concentrate on clarifying points or on scoring them.

    Comment by Ray Ladbury — 30 Aug 2007 @ 8:11 AM

  294. re 293 and sophistry…

    ===========

    More than a bit off-topic, to say the least, but for some odd reason, call it a weird itch at the back of my consciousness, I am reminded more and more that “Sphere” is also the title of a sci-fi novel.

    Not that I expect this post to make it to the discussion, mind you…very off-topic, indeed.

    Comment by J.S. McIntyre — 30 Aug 2007 @ 10:10 AM

  295. Re 283: Thanks Mauri for the link. It cleared up a question that was starting to bother me. (See way down on the cited page)

    My question was: Was this rapid melting a meteorological or a climate phenomenon?

    The answer seems to be that it was mainly a meteorological one. A durable high pressure area was set up in May over the Arctic ocean with very clear skies, and an increased amount of solar energy was received at the surface. Then there was strong feed-back due to lower albedo (pools of water over ice).

    The causation issue with respect to climate change seems approximately the same as with the multi-year droughts and record heat waves. That is, the causation mechanism remains uncertain.

    (My judgment on this issue tends to be that global warming has, and will have, most certainly impacts on all these spectacular phenomena – but that the impacts are unknowable in any single case. For instance, it is impossible to know if the N.O. Superdome was in fact endangered or if it was saved from collapse by the impacts of global warming on hurricane Katrina. We have to live with that kind of uncertainty, accept some additional risk. The weather statistics have changed.)

    This Arctic melting case has an interesting component. There is a lot of “memory” involved. What will be the fate of the extra energy that was received and captured in the surface waters? How will it be mixed, circulated and dissipated?. Still, if the melting will expand next summer depends mostly on the weather, although the starting level will probably be favorable for a further reduction.

    Comment by Pekka Kostamo — 30 Aug 2007 @ 3:02 PM

  296. Since 2002, I have said 2020 was to be the time of a blue arctic ocean in the summer. With this years results, I am updating that to 2011. Overall, I agree with Walt Bennett. It seems to me that it all started when we lost the overall ice thickness and mass between 1989 and 2000. This loss occurred without the benefit of the albedo feedback. The mechanism for this loss has not been explained or understood to my knowledge. Now with the albedo feedback kicking in, the ice is quickly melting. How warm will the Arctic Ocean become in summers now? How much will Greenland melting accelerate? What is the name of the next climate age? [May I suggest Ohshitocene -- as in we sure didn't see this coming!]

    Comment by Craig Dillon — 30 Aug 2007 @ 3:37 PM

  297. Re 288: “You can argue about whether the climate is chaotic, but it is a non-linear dynamical system with negative and positive feedbacks. So long as the negative feedbacks dominate you have a stable system such as that over the last 10,000 years. But if the positive feedbacks dominate then you have a rapidly changing system just as we had 10,000 years ago at the end of the Younger Dryas. The positive feedbacks cause the system to runaway until it gets into a new state where the negative feedbacks again dominate. The new state is then stable, and it will sit there for perhaps another 10,000 years.

    But the next rapid change is only a few years/months away!”

    Yes — if the rapid change isn’t in progress; which we won’t know for a while. I haven’t argued whether climate is chaotic or not — except to speculate that all natural systems are chaotic.

    Do you propose that the climate can be accurately modeled by some unchanging numeric equation of some finite degree? That is: Does the nature of climate remain unchanging over time?

    (P.S. Can we reclaim negative and positive feedback from society at large, or are we stuck with negative feedback being a negative?)

    Comment by Sphere — 30 Aug 2007 @ 5:08 PM

  298. “Paul Crutzen, a Nobel Prize winner for his work on the ozone layer,
    has set out to give the future a new name.

    The Anthropocene Epoch: In Favor

    “In a stirring 2000 paper, … proposing to use the term ‘anthropocene’ for the current geological epoch.” He repeated his proposal to a much larger audience in a January 2002 Nature article.

    “This is a well-worded and precise proposal….

    “… his name is only a proposal, which would have to be ratified by the world’s major scientific organizations first….”

    Links to the papers and more info in the full article, which I recommend:

    http://geology.about.com/od/geotime_dating/a/anthropocene.htm

    Comment by Hank Roberts — 30 Aug 2007 @ 5:11 PM

  299. Craig Dillon (#296) wrote:

    Since 2002, I have said 2020 was to be the time of a blue arctic ocean in the summer. With this years results, I am updating that to 2011.

    According to Cryosphere Today, we were below 3 million km sea-ice area on Tuesday, more than 25% below the previous all-time low of 4 million set in 2005. I’d would try and relax: at this rate we have another five years of summer sea-ice. 2013.

    Comment by Timothy Chase — 30 Aug 2007 @ 5:14 PM

  300. Re 292: “Even if the ice does recover this winter, it may not mean much, as it takes far less energy to melt freshly created thin first year ice, than it does to melt thick multiyear ice.”

    I’m vaguely aware of that — but I don’t think we’ve got a good measure of ice volume and mass about as a talking point. I’ll just say that if the ice recovers this winter I’ll wait to see the next summer’s melt before making a guess on when the Arctic will be ice free.

    If the ice falls 1 million km short I’m betting on two more melt cycles. If not then I’m not ready to bet.

    Comment by Sphere — 30 Aug 2007 @ 5:18 PM

  301. http://science.natice.noaa.gov/icImages/qs_07241_nheimsk_00z.png
    http://science.natice.noaa.gov/icImages/n2_07242_n_12z.png

    Do read the text for information on accuracy, these are _pictures_ after processing data.

    These are via the link given in the first post, where it says:

    “The Naval Sea ice center has a few different algorithms (different ways of processing the data) that give some sense of the observational uncertainty ….”

    Comment by Hank Roberts — 30 Aug 2007 @ 5:20 PM

  302. Re 293: “While a circle may be merely a useful construct, a Sphere evidently does exist ;-) and can either concentrate on clarifying points or on scoring them.”

    I happen to disagree. I’d ask you to prove to me that I exist if that wasn’t so far afield from the topic.

    (You might take note that there are people here I’m happy to agree with. It’s just a certain attitude and bogus view of Science with which I disagree. I find Scientism a very disagreeable religion.)

    Comment by Sphere — 30 Aug 2007 @ 5:24 PM

  303. Re 294: “Not that I expect this post to make it to the discussion, mind you…very off-topic, indeed.”

    You noticed! :)

    Comment by Sphere — 30 Aug 2007 @ 5:38 PM

  304. Re 296: “[May I suggest Ohshitocene — as in we sure didn’t see this coming!]”

    Ever since I bought my house overlooking Boston in 1990 I’ve said that I bought valuable oceanfront property — it was only a question of when. I think I might even live to see when.

    Greenland ought to be fairly slow to melt away. So I think two years from now the major topic will be the Antarctic Peninsula, and two or three years after that the Ross Ice sheet and Western Antarctica. I won’t even have retired by then.

    Comment by Sphere — 30 Aug 2007 @ 5:46 PM

  305. On Climate:

    It might be the state of climate research that it is about long-term averages, but climate is what the weather will be in the future where you live, not what the weather has been in the past where you live.

    Do you live in a cold dry climate or a warm wet climate?

    Comment by Sphere — 30 Aug 2007 @ 5:53 PM

  306. Alastair McDonald 29 August 2007:
    “You can argue about whether the climate is chaotic, but it is a non-linear dynamical system with negative and positive feedbacks. So long as the negative feedbacks dominate you have a stable system such as that over the last 10,000 years. But if the positive feedbacks dominate then you have a rapidly changing system just as we had 10,000 years ago at the end of the Younger Dryas. The positive feedbacks cause the system to runaway until it gets into a new state where the negative feedbacks again dominate. The new state is then stable, and it will sit there for perhaps another 10,000 years.”

    It’s maybe worth noting here that negative feedback-dominated systems are not inherently stable. It depends on the relative strengths of feedback and damping. Strong negative feedback combined with little damping produces a system that wants to oscillate – and will at the slightest provocation.

    Of course, our climate system is strongly damped (by the ocean thermal inertia). Which is presumably why it doesn’t oscillate much on our timescales, despite strong negative feedback from the longwave radiation mechanism. Of course, on longer timescales and in other states, our climate does oscillate. That is presumed ([I]shown[/I], for the ice age cycles) to be due to sub-scale positive feedbacks within the overall negative feedback regime from temperature vs radiation to space.

    Comment by Glen Fergus — 30 Aug 2007 @ 6:52 PM

  307. For any ship captains following this thread who are trying to make their way through the NorthWest Passage (and those of you still following this thread), you better put the engines at 110% because the sea ice is rapidly refreezing.

    Don’t believe the images from the Cryosphere Today. You might only have a day or two left.

    http://rapidfire.sci.gsfc.nasa.gov/realtime/single.php?2007242/crefl1_143.A2007242221000-2007242221500.4km.jpg

    False-color image with sea ice in Red.

    http://rapidfire.sci.gsfc.nasa.gov/realtime/single.php?2007242/crefl1_367.A2007242221000-2007242221500.4km.jpg

    Comment by John Wegner — 30 Aug 2007 @ 8:16 PM

  308. #307: Refreezing? In the last week of August?

    What ship’s captains actually use are charts like this:
    http://www.natice.noaa.gov/pub/West_Arctic/beaufort_sea/2007/currentcolor.pdf

    … and this:
    http://ice-glaces.ec.gc.ca/prods/WIS40CT/20070830180000_WIS40CT_0003296413.pdf

    The Canadians plot new ice in pink. See any pink there, John?

    Comment by Glen Fergus — 30 Aug 2007 @ 10:26 PM

  309. #307, Mr Wegner I live by the Northwest Passage, and I heard that ships have had pleasant sailing lately. “A day or two left” utter nonsense, more ships are on their way. Is there any reason to believe your reasoning then?

    Comment by wayne davidson — 30 Aug 2007 @ 10:49 PM

  310. #288 Alastair, I take it you are from the UK? Well I am a little puzzled by the met office no longer displaying sea ice extent yearly projections until 2100. I am getting convinced that the ice and Polar atmospheric models were off by 10 to 20 years, would have really appreciated seeing their projections still, as I am curious about how we take it from here. Is the met office ice model merely wrong timewise? It will be very good to understand where the error is, especially compare the 2007 melt with 2007 projection, it would help narrrow down a bug, and perfect future models. I don’t think its bad yo be wrong, it is terrible when you can’t know why.

    Comment by wayne davidson — 30 Aug 2007 @ 11:14 PM

  311. Do you have a point? Does refreezing somehow discredit the minimums which have already been recorded?

    Comment by dhogaza — 30 Aug 2007 @ 11:19 PM

  312. #310 Wayne Davidson.

    The Met Office are still showing ice area projections.
    http://www.metoffice.gov.uk/research/hadleycentre/models/modeldata.html

    From Hadley Ctr Briefing “Climate change and the greenhouse effect”(Dec 2005) page 44:
    “Under the High Emissions scenario we find that ice in the month of September (when it is at its minimum extent in the annual cycle) will have almost completely disappeared on average by the 2080s.”

    ___Does anyone have any refs about the climate impacts of an ice-free Arctic Summer?___

    Leaving sensible warming rate impacts aside: Will changes to heat flux (ice insulates atmosphere from ocean) and availability of water with regards humidity really have no effect on the Arctic Oscillation? I’ve been checking through AR4 and the ACIA, but can’t see this discussed and can’t find anything in Google (although with my day-job and this issue I have been burning the candle at both ends – so apologies if I’m missing the obvious).

    PS What’s the contrarist reaction to this news?
    Actually don’t answer that.
    I don’t care.

    Comment by CobblyWorlds — 31 Aug 2007 @ 1:57 AM

  313. RE # 312, Cobbly, thank for the link to the Met Office page but Please help me to understand the March 2100 ice concentration. Is that their idea of a joke?

    Comment by John L. McCormick — 31 Aug 2007 @ 8:16 AM

  314. Wayne, you’ve opened the wrong Talking Points Packet, that “Arctic Freezing Fast” set is from the September Denial series.

    Comment by Hank Roberts — 31 Aug 2007 @ 8:51 AM

  315. All that new to the SW of Banks Is literally showed up overnight. Plus, the ice edge moved south along the Banks shore. I agree, anyone attempting the passage now is a risky gambler.

    Comment by SteveSadlov — 31 Aug 2007 @ 10:55 AM

  316. RE: #308 – The Canadian chart is in error. Areas K and I are definitely new ice. I track this daily.

    Comment by SteveSadlov — 31 Aug 2007 @ 10:59 AM

  317. #313 John,

    In the winter there’s still a loss of long wave into space, but no incoming short wave from the Sun so initially it didn’t strike me as odd.

    However A1b is 717ppm CO2 in 2100 which brings it up towards Cretaceous levels. And according to this abstract (not read actual paper) http://www.nature.com/nature/journal/v380/n6572/abs/380330a0.html
    “We find that the Arctic Ocean was relatively warm, remaining above 0 °C even during the winter months. This implies that there was significant poleward heat transport during all seasons.” That was published in 1996.

    Comment by CobblyWorlds — 31 Aug 2007 @ 12:07 PM

  318. #314, Hank, I agree with some previous post, there should be a way to flag nonsense, and warn RC readers of how ridiculous some statements are, this would decrease contrarian useless arguments driven to distract rather to inform.

    #312 Cobbly, Many thanks for the link, could not find again, much appreciate this I can’t slow down the projection pace, but I can see where they got at least 2007 melt wrong. The melt of June 2007 occurred over the middle of the Arctic gyre, which is seen as happening in 2038. This is key in understanding what happenned, I believe it is due to unnusually warm air at the usual location where a high pressure system settles North of Alaska almost throughout the entire year. I don’t have June’s weather animation, but I think it is so. Must remind that in 2005 a stagnant High pressure system settled over Northerrn Arctic Quebec, giving +30 C surface conditions in late April early May (if memory serves) . This is serious evidence of a potential catastrophic meltdown to come, if such a “hot” high pressure system settles over the thickess ice in the Polar region. Met Office projection shows strong yearly melting on the Russian side, but not so much on the Canadian side.
    In Large I think that it underestimated warming from a very different atmosphere than we are use to…

    Many thanks Cobbly, I think its important that contrarians explain their reasoning, this shines a great light on them…. Bookmarked the animation.

    Comment by wayne davidson — 31 Aug 2007 @ 12:45 PM

  319. Re 306: “It’s maybe worth noting here that negative feedback-dominated systems are not inherently stable. It depends on the relative strengths of feedback and damping. Strong negative feedback combined with little damping produces a system that wants to oscillate – and will at the slightest provocation.”

    Um… I think there is a disagreement here about what the term “negative feedback” means.

    My understanding of the term is: Any response which tends to increase when a system diverges from a meta-stable state and which tends to pull the system back towards that state.

    Positive feedback is any response which also tends to increase as a system diverges from a meta-stable state and which tends to pull it away from that state.

    Responses which do not either tend to draw a system back to the meta-stable state or pull it away from that state are uncharacterized by the terminology.

    Note that this definition does not define any given response as necessarily positive or negative — but only as positive or negative relative to a given meta-stable state.

    By the definition I understand, a system dominated by negative feedback must necessarily remain near some meta-stable state for the duration of the time in which it is dominated by negative feedback. If it wanders off to some other meta-stable state it must have been dominated by positive feedback during the transition. (A transition called re-organization.)

    Certainly, strong responses to perturbations can pull a system any which way, but unless the response does a fairly good job of pulling the system back to a specific state from divergences either way it isn’t negative feedback.

    [Response: The use of the terms positive and negative feedback in climate and engineering differ, and your definitions aren't quite what is meant when these things are discussed in climate papers. I recommend the early Hansen papers to get a better sense of the climate usage. - gavin]

    Comment by Sphere — 31 Aug 2007 @ 5:36 PM

  320. Re: “[Response: The use of the terms positive and negative feedback in climate and engineering differ, and your definitions aren’t quite what is meant when these things are discussed in climate papers. I recommend the early Hansen papers to get a better sense of the climate usage. - gavin]”

    I’m perfectly satisfied with the “In Nature” section of this Wikipedia entry: http://en.wikipedia.org/wiki/Feedback See also the root General Systems notion of Feedback: http://en.wikipedia.org/wiki/Systems_theory

    As you can see, I was not using feedback in the narrow cybernetic sense; which is consistent with the general usage, but much more restrictive.

    I have no intention of accepting or using any domain specific notion of feedback which is contrary to the general notion.

    Comment by Sphere — 31 Aug 2007 @ 8:38 PM

  321. As I predicted yesterday, the NorthWest Passage is now closed off by the sea ice (unless you have a good icebreaker.)

    There are three different routes to take which are shown on Wikipedia here.

    http://en.wikipedia.org/wiki/Image:Northwest_passage.jpg

    The Northern route is choked off by the ice in the Beaufort Sea. The middle route is touch and go but appears to be choked off as well. The southern route is iced up the middle (which is what the early explorers always complained about – that the ice seems to come out of nowhere in the inner passage ways of the NorthWest passage.)

    You might need to use the 500M resolution of this Terra satellite image to see it given the cloud cover. The 500M resolution allows one to zoom into the different routes and see the ice.

    http://rapidfire.sci.gsfc.nasa.gov/realtime/single.php?2007243/crefl1_143.A2007243193500-2007243193959.500m.jpg

    In a way, this situation is no different than that experienced by the early explorers. They might make progress, but then suddenly they are frozen in for two straight years. In the third year, in late August, suddenly the ice opens up and they are able to squeak through. In the last two years, there was no way any ship was getting through the NorthWest Passage. This year, there has been a 2 week window to make it through. If you started at Baffin Island today, however, you are stuck for the next two years.

    Noone with a $100M in cargo is going to park a ship off Baffin Island in early August and wait for the satelitte images to tell them which route to take over the next two weeks before the end of August (when everything refreezes) and when there are so many risks of different routes iceing up the next day. With more warming, maybe.

    Comment by John Wegner — 31 Aug 2007 @ 8:57 PM

  322. [[As you can see, I was not using feedback in the narrow cybernetic sense; which is consistent with the general usage, but much more restrictive.

    I have no intention of accepting or using any domain specific notion of feedback which is contrary to the general notion.]]

    Oh, and I suppose you use “work” to mean “any effort” even when discussing physics? And use “culture” to mean “going to the opera and art museums” even when discussing microbiology? And use “theory” to mean “wild guess?” What other technical definitions do you avoid when talking about the fields where those terms are used differently?

    Comment by Barton Paul Levenson — 1 Sep 2007 @ 6:23 AM

  323. No new ice has formed in the Canadian Arctic. However over the next week, new ice (slush) may form in the sheltered bays of the high arctic.

    The last time I checked, McClure strait has 1/10 to 2/10 ice, with this ice being thick first year or multiyear ice.

    Now the wind can quickly push old year ice around and pile this ice up around islands. You are always in danger of the having the old ice in the beaufort sea, entering McClure Strait and blocking the Northern route of the North West Passage. However the southern route, which is tricker to Navigate, should be clear for several more weeks.

    Another point, when the Canadin charts show blue instead of white, it means that its not ice free but less than 1/10 coverage. Once again, wind conditions can push thin

    Comment by Larry — 1 Sep 2007 @ 8:09 AM

  324. John Wegner (#321) wrote on August 31:

    As I predicted yesterday, the NorthWest Passage is now closed off by the sea ice (unless you have a good icebreaker.)…

    Noone with a $100M in cargo is going to park a ship off Baffin Island in early August and wait for the satelitte images to tell them which route to take over the next two weeks before the end of August (when everything refreezes) and when there are so many risks of different routes iceing up the next day. With more warming, maybe.

    Well, I would certainly hate to use early August pictures to navigate in late August. And that would seem to be the right location, although I see plenty of blue towards the south. So lets see how Nasa describes the ice as of August 30th, 2007 using an image from the day before…

    This image shows the islands north of mainland Canada adjacent to Greenland, as observed by the the Moderate Resolution Imaging Spectroradiometer (MODIS) flying on NASA’s Aqua satellite on August 29, 2007. … the sea ice pack that normally covers the water between the islands is absent. Areas often choked with ice at this time of year, but free of it in this MODIS scene, include the Parry and McClintock Channels and the McClure Strait. Larsen Sound and Victoria Strait are hidden beneath cloud cover, but they are also largely free of sea ice. This provided a nearly ice-free connection between Baffin Bay (a long body of water between Canada’s Baffin Island and Greenland that is regularly ice-free in summer) and the Arctic Ocean. An ice-free gap between the North American mainland and the Arctic sea, not shown here, extends all the way to the Bering Strait between Alaska and Russia, creating a connection almost free of all sea ice from the North Atlantic to the North Pacific.

    Northwest Passage Nearly Open
    http://earthobservatory.nasa.gov/NaturalHazards/natural_hazards_v2.php3?img_id=14479

    If you check out the rest of the webpage it is clear that the passages were more difficult to navigate in early and mid August than they were on the 29th. If it is choked with ice relative to the earlier part of the month and you were able to see it rapidly closing on the 30th, I gather that it is freezing over at breakneck speed…

    Comment by Timothy Chase — 1 Sep 2007 @ 9:52 AM

  325. Sphere writes:
    “I’m perfectly satisfied with the “In Nature” section of this Wikipedia entry”

    Someone needs to update that Wikipedia entry to add the usage from climatology, obviously.

    Sphere, if you use the search tool at the top, you’ll find a long series of confused postings from an engineer whose definition of “feedback” also differed. It’s much like trying to talk to a lawyer, who has come out of law school with “infer” and “imply” reversed.

    You either understand how the field uses the term, or waste time.

    Comment by Hank Roberts — 1 Sep 2007 @ 5:09 PM

  326. Notwithstanding the cruise ship which has just left Resolute Bay today, and more ships to come, it has been the best ice free year in a series of ever decreasing ice coverage in the Northwest passage. The Northwest passage was never traversed in the distant past mainly by its great stigma given by the death of many explorers/whalers daring to penetrate it. Now it is a “walk in the park”mostly ice free sail, recent past huge pack ice floes are none existing of extremely rare… I don’t appreciate comments which are misleading on RC, and I guess responding to them is the only recourse.

    Present day met dynamics are very interesting, especially with extremely warm sst’s”

    http://www.osdpd.noaa.gov/PSB/EPS/SST/climo&hot.html

    Very very warm in the open section of the arctic ocean, we are experiencing a warm september in the High Arctic +7 C again despite a High Pressure
    in the SW quadrant of the North American Arctic Ocean. The sun is quite lower than summer just past yet the heat is still on.

    Comment by wayne davidson — 2 Sep 2007 @ 12:09 AM

  327. Hank,

    Feedback was a term invented by electrical engineers to describe non-linear processes long before a butterfly fluttered in Lorenz’ brain. It is quite clear, since they think that they can redefine the term, that climatologist do not understand feedback. That explains why they have so wildly underestimated the melting of the Arctic ice.

    The re-closing of the North West Passage is just a minor aberation caused by some loose ice being blown south. You can check out the day by day sequence on my Javascript web page: http://www.abmcdonald.freeserve.co.uk/north.htm by clicking Backward s Day.

    The real situation is that the Arctic sea ice has been thinning steadily for about 20 years. Now it is so thin that the edge of the perennial sea ice melts and retreats further each summer. The more ice that melts, then the warmer the sea becomes from being exposed to the solar radiation. This melts more ice, and so there is a positive feedback with warming causing melting and melting causing warming.

    This year the edge of the perennial ice stopped its major retreat at the end of July as is normal, but next spring the ice will not have fully recovered because the extra exposed sea surface is warmer than usual, and so will inhibit the regrowth of the seasonal sea ice.

    Next year, because the ice melt will get a head start, more ice will be lost before the start of August, perhaps all of it. If not we will surely see the last of the summer ice within a year or two driven away due to the positive feedback from the ice albedo effect. No matter how the climatologists try to define feedback, that will not change the physical system.

    They tried to define the adiabatic lapse rate to fit the US Standard Atmosphere, then wonder why they have a tropical lapse rate problem. It is a great pity that the competence of today’s climatologists does not match their hubris :-(

    Comment by Alastair McDonald — 2 Sep 2007 @ 2:20 PM

  328. Re #319, #320
    Perhaps the disagreement stems not from the definition of a negative feedback, but from the way in which the concept is used. For example, radiative equilibrium is attained when absorption equals emission. If the temperature is increased slightly WHILE HOLDING THE INCOMING FLUX CONSTANT, emission becomes greater than absorption, causing the temperature to fall back toward its equilibrium value. Thus, the increase in emission with temperature represents a negative feedback in the classic sense and the equilibrium is stable. However, if the system warms due to external forcing, e.g., an increase in the incoming flux, the role of a negative feedback is to slow down the rate of increase, eventually causing the system to settle into a new equilibrium.

    Comment by Jerry — 2 Sep 2007 @ 2:25 PM

  329. Re #306
    “Of course, on longer timescales and in other states, our climate does oscillate. That is presumed ([I]shown[/I], for the ice age cycles) to be due to sub-scale positive feedbacks within the overall negative feedback regime from temperature vs radiation to space.”

    This comment seems to assume that the glacial/interglacial cycle was a free oscillation; it is generally accepted, however, the the oscillations were FORCED by spatial and temporal redistributions in insolation due to the “wobbling” of the earth’s axis. (Milankovitch theory)

    Comment by Jerry — 2 Sep 2007 @ 2:58 PM

  330. Good news today…

    The arctic sea-ice seems to be continuing to bounce back rather strongly at the moment.

    http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/sea.ice.anomaly.timeseries.jpg

    Still, it is rather early in September.

    Comment by Timothy Chase — 2 Sep 2007 @ 8:55 PM

  331. Re #330: Timothy, it’s not bouncing back, not yet anyway. The anomaly plot you linked to does indeed show the ice going up, but that’s in relative terms. The accompanying ice area plot is basically flat.

    Comment by Steve Bloom — 3 Sep 2007 @ 1:48 AM

  332. I wonder if the rebound or the ice area is due to the melt ponds refreezing. One of the problems with the calculating ice area, is that it hard to tell between open water, and melt ponds on the ice. Considering that the rebound is quite small however, it appears that Cryosphere today has a fairly good handle on this problem.

    What I find amazing is that places like Alert,NWT (83 North is still recording temperatures above freezing), with the Sun barely above the horizon for most of the day.

    This tends to indicate that the Arctic Ocean has good heat content, and is having an effect in extending the summer in the high arctic.

    The NSIDC results for ice area should be out in a few days, and I expect the ice area will show a continued but slow decrease in ice for the next two-three weeks.

    The Cryosphere results will be up and down depending if new ice melt, melt ponds refreezing, and possible formation of new and nilas ice in the next few weeks, fight it out for control.

    But the days of rapid ice decline are over for this ice season. Soon the discussion will turn to how slow the ice recovery is during the winter.

    Comment by Larry — 3 Sep 2007 @ 7:12 AM

  333. Hank,

    I am very surprised to read the postings regarding the definition of feedback, arising once again. Can you provide me a few more pointers on using this site’s search tool, so that I can find the confused postings to which you refer? I would like to follow up this post with a more researched thought-through posting. Unfortunately, I am unable to get the search tool to hone in on the material you reference.
    Let me first postulate that all feedbacks in nature have fundamental analogies, based in the mathematics, whether in climate systems, engineering control systems, or as implemented by the helmsman on the Staten Island Ferry in order to minimize his transit time in the presence of wind and currents. This seems to be a wonderful opportunity then to open a cross-discipline discussion and educate those truly curious about climate issues, rather than to create a divisive internet shouting match, without a mathematical basis, on whose feedback belongs to whom.
    For instance, even with my limited use of feedback in five or ten engineering classes, I feel that I possess some appreciation for the concern of ice albedo feedback. Yes, I would like to know more details, but I get the idea well enough to understand what I need to, and don’t feel the need to poke at the experts without doing my own research. However, I have a day job and a family so I choose to leave it there. I at least believe for now that my study of feedbacks also enabled me to conceptually understand the post on water vapor as a feedback.
    Without looking too far into it, I suspect that the real differences have to do with the complexities and underlying assumptions, including linear vs. non-linear systems, parametric variabilities, and complexities arising from multiple simultaneous feedbacks, rather than whether a feedback is fundamentally unique to a certain discipline. I do remember the blog shouting match with the poster-boy engineer from some time ago, but don’t remember the details other than I discounted the postings because (as I recall) there was very little detail present to underpin that commentator’s assertions and arguments, and a blog is rather ill-suited for resolving such fundamental allegations anyway. Yes, the devil is in the details, and we must have them, but conveying the concepts of global warming to a more broad audience is essential. Feedbacks are an important element of that dialog, and stating that noone but the climate experts understand is to miss a golden opportunity.

    Comment by The Wonderer — 3 Sep 2007 @ 12:00 PM

  334. Re #327
    “The more ice that melts, then the warmer the sea becomes from being exposed to the solar radiation. This melts more ice, and so there is a positive feedback with warming causing melting and melting causing warming.”

    This is precisely how climatologists define the ice-albedo feedback. It would appear that some of the bloglodytes who make frequent posts here are just trying to stir up controversy where none, in fact, exists.

    Comment by Jerry — 3 Sep 2007 @ 1:38 PM

  335. > feedback, definitions

    Well, interestingly enough, search this with Google:
    +realclimate +engineer +definition +feedback

    you’ll find there are a lot of postings recently on skeptical sites making comments about this very question. Odd coincidence, perhaps.

    I’ll leave it to the climatologists after reminding you of the pointer Gavin gave earlier to Hansen’s earlier papers as a place to start.

    Comment by Hank Roberts — 3 Sep 2007 @ 3:21 PM

  336. Re #291 where Hank Roberts Says:

    Alastair, please. That was published last year and there’s an entire thread here at RC about it. “The whole of science” isn’t “hung up on linear trends.” You’re in the mainstream.
    and he cites as justification: Arctic Sea Ice decline in the 21st Century http://www.realclimate.org/index.php/archives/2007/01/arctic-sea-ice-decline-in-the-21st-century/#more-391

    It is true that in the commentary by Cecilia Bitz she dismisses the idea behind Figure 3 http://www.realclimate.org/images/bitz_fig3.jpg where a straight line is drawn to meet the zero ice line in 2100. However, what she does do is suggest the ice might go in 2040 which fits to a straight line drawn on Figure 2. Try it with http://www.realclimate.org/images/bitz_fig2.jpg

    Of course the results from her experiment do show a sudden collapse. See http://www.realclimate.org/images/bitz_fig1.jpg but that model still has residual September ice well after 2040. This is where the climate modellers do not seem to understand what positive feedback means. When positive feedback takes over, and it has done, the reduction is sea ice area will accelerate until no ice is left. That is what positive feedback means!

    Jerry may think that my engineer’s definition of ice-albedo feedback is the same as that of climatologists, but Gavin has written that their definition is different. He has only given us a vague reference to early Hansen papers. Gavin, or perhaps Hank, could you give us a reference to an open access paper where we can read Hansen’s definition?

    Comment by Alastair McDonald — 3 Sep 2007 @ 4:24 PM

  337. Re #329:

    The intent was the opposite – that the glacial-interglacial cycles are not free oscillations, rather forced by orbital variations, as you say. But Milankovitch alone is way too small to explain the observed amplitude. You need positive feedback to amplify the orbital forcing – the most important being the carbon cycle effect on atmospheric CO2 conc.

    Comment by Glen Fergus — 3 Sep 2007 @ 7:45 PM

  338. Hank, speaking of feedback, the lack of a sudden massive biological feedback may have played a role in the demise of the ice this year. Not well known, however I have seen it for years, there’s a cloud seeding chemical release from under the ice biological activity or simple chemicals like bromides :

    http://www.fysik.lu.se/eriksw/aoe2001/EOS_AOE2001_Leck.pdf

    In the recent past, a solidly frozen Arctic Ocean gave a mighty release of cloud seeding chemicals at about mid April onwards which nullified the higher sun heat. If these aerosols were released gradually throughout the winter, instead of suddendly in the spring, there would be a greater ice melt by the lowering of cloud albedo. This might have happenned, need a word by those who have access
    to high resolution data…….

    Comment by wayne davidson — 3 Sep 2007 @ 10:57 PM

  339. Further to #336

    I have found a paper by Hansen et al. (1984) “Climate Sensitivity: Analysis of Feedback Mechanisms”, Reprinted from Climate Process and Climate Sensitivity Geophysical Monograph 29, Maurice Ewing Volume 5 Copyright 1984 by the American Geophysical Union. http://pubs.giss.nasa.gov/docs/1984/1984_Hansen_etal_1.pdf

    They “calculate land ice, sea ice and vegetation feedbacks for the 18k [at the last glacial maximum (LGM)] climate to be f(land ice) ~ 1.2 – 1.3, f(sea ice) ~ 1.2, and f(vegetation) ~ 1.05 – 1.1 from their effect on the radiation budget at the top of the atmosphere.”

    My point is that positive feedbacks lead to an increase in the forcings. It is wrong to use an average forcing, when it is increasing exponentially.

    This is similar to point that is being make by falafulu in his post at http://www.realclimate.org/index.php/archives/2007/08/regional-climate-projections/langswitch_lang/index.php?p=442#comment-51812
    The whole ethos of climate modelling is wrong, and I con only assume that this is because is minly being dome by mathematicians. For them an average temperature is a higher truth than a set of temperature readings becasue it hads been mathematically manipulated and maths is never wrong. However, what they have really done is throw away most of the information, so in fact the average is less true than the original data. This can be seen when the size of the average US family is calculated to be 3.14 people. That answer, with a precision of two decimal places, does not match reality.

    But now, not satisfied with taking averages, they have moved on to Bayesian statistics. I am not the only person to object to that method. See http://en.wikipedia.org/wiki/Bayesian_probability#Controversy

    Comment by Alastair McDonald — 4 Sep 2007 @ 5:40 AM

  340. RE # 327

    Alastair, you said:

    [The more ice that melts, then the warmer the sea becomes from being exposed to the solar radiation. This melts more ice, and so there is a positive feedback with warming causing melting and melting causing warming.]

    While observers are fixated on the extent of and diminishing rate of Arctic ice melt back, I am wondering about the massive heat about to be given off to the atmosphere and its destination. Can Moscow expect another late and mild winter?

    I begin with the 15 million sq km of Arctic Ocean and the now approximate 3 million sq km of remaining ice. The black surface is, in my estimation, about 4.6 million square miles of warm water about to freeze.

    Sphere at #239 provided a link to SST anomalies that indicate about a 5C anomaly in the far western Arctic. I do not know the average SST throughout the Arctic but I will assume it is averaging 37F .

    The refreeze begins with evaporating water heat. The process of evaporation 7.5 times as much energy as freezing and the latent heat of fusion of ice require 79.6 cal/gm or 143.3 Btu/lb. Evaporation takes away about 540 cal/gm or 975 Btu/lb. I am using 1000 Btu/lb to evaporate sea water.

    From NSIDC (All About Sea Ice): the freezing temperature of salt water is lower than fresh water; ocean temperature must reach 28.8 F to freeze. Because oceans are so deep, it takes longer to reach the freezing point and generally the top 100 to 150 meters of water must be cooled to the freezing temperature for ice to form.

    Assuming an extreme average Arctic open water temperature at 37 F, the evaporation process could release 636 x 10(18) Btus to bring the surface water to 28.8 F.

    Then, the latent heat of fusion of ice takes over. Assuming the nearly 12 million sq km. melted surface froze to a depth of 3 feet (my assumption), would yield an additional 3×10(18) Btu for a total of about 640 x 10(18) Btu released to the atmosphere throughout the entire surface water to sea ice change.

    If my assumptions are off base, they do not dismiss the large question of where the freezing open Arctic Ocean heat will dissipate to and what will be its impact.

    Any thoughts?

    Comment by John L. McCormick — 4 Sep 2007 @ 8:43 AM

  341. Hank,

    I performed the search you recommended and located a lot of blather. If this is about an assertion that positive feedbacks cannot lead to another stable state, then this is untrue in engineering and other disciplines. And feedbacks in engineering control systems can be plenty complex, just ask any designer of a nuclear power plant’s control system. It’s hard to sort through all the comments on those listings to find relevant comments on this topic, but at a glance I don’t see anyone discussing the mathematical underpinnings, again, just shouting. Also, I’m gonna need a better citation than “Hanson’s early work.”

    Comment by The Wonderer — 4 Sep 2007 @ 9:11 AM

  342. To find the early Hansen papers, first, spell his name right.
    Hansen
    +climate +NASA +GISS +publications

    Comment by Hank Roberts — 4 Sep 2007 @ 10:12 AM

  343. re 330
    I take that to be big ice breaking up into little ice, and the little ice speading out and looking like more ice at the resolution of the sensors.

    Both the water and the air are too warm for such significant ice formation. However, there are winds that would facilitate dispersion of broken ice. Look at changes in the ice near ~75 N and ~135 W.

    Comment by Aaron Lewis — 4 Sep 2007 @ 12:41 PM

  344. A good treatment of feedbacks in a climate context can be found in section 2.5 of Peixoto and Oort, “Physics of Climate”. For those who are desirous of obtaining a more rigorous understanding of the physical underpinnings of climate change than can be obtained from the internet, this would be a good book to purchase.(It’s still in print and available from Amazon.com)

    Comment by Jerry — 4 Sep 2007 @ 2:09 PM

  345. RE: #341 and others – so, here is what those who wrest a livelihood from (and risk there lives on) northern waters bank on. This is as of yesterday. A good / scary crab fisherman will play chicken with the ice edge (what is shown in “Deadliest Catch” is for real):

    http://pafc.arh.noaa.gov/marfcst.php?fcst=FZAK80PAFC

    THE MAIN ICE EDGE LIES FROM THE WESTERN COAST OF BANKS ISLAND TO 71.1N 132.5W TO 70.8N 135.9W TO 71.2N 138.2W TO 71.4N 143.0W 71.8N 145.0W 72.3N 149.9W 72.9N 152.0W 74.4N 154.8W AND CONTINUES TO THE NORTHWEST. THE EDGE IS MAINLY 1 TO 4 TENTHS NEW…YOUNG…FIRST YEAR THIN AND MULTI YEAR ICE.

    FORECAST THROUGH SATURDAY…EAST WINDS OF 10 TO 20 MPH WILL CONTINUE AROUND THE VICINITY OF THE ICE EDGE FOR THE NEXT 5 DAYS. NEW ICE WILL FORM NEAR THE ICE EDGE AND WITHIN THE PACK AS TEMPERATURES DROP BELOW FREEZING. LITTLE NET CHANGE IN THE POSITION OF THE EDGE THIS WEEK.

    Comment by SteveSadlov — 4 Sep 2007 @ 2:20 PM

  346. The Sept 3 update is out at NSIDC (National Snow and Ice Data center. NSIDC Sept 4 Update

    The sea ice extent continues to decline and is now down to 4.42 sq. km, or below what it should be by 2050, according to the UN climate report projections earlier this year.

    Comment by Larry — 4 Sep 2007 @ 3:04 PM

  347. Sea ice extent is 4.42 million square kilometers, as of Sept. 3, or 0.9 million square kilometers less than the absolute minimum measured for Sept. 20-21, 2005. See: http://www.nsidc.org/news/press/2007_seaiceminimum/20070810_index.html.

    Have any climate simulations ever shown such a rapid drop in a single year? If not, what is missing from the models? Heat transfer via ocean currents (i.e. W. Maslowski’s thesis)? Overestimates of sea ice volume in the past?

    I’m an RNA biochemist, so maybe I’m over-impressed by this sudden drop. What’s the take-home message for the average RealClimate reader?

    Comment by Jamie Cate — 4 Sep 2007 @ 3:14 PM

  348. “Physics of Climate” is on google books and can be read on-line
    http://books.google.com/books?id=3tjKa0YzFRMC&dq=physics+of+climate&printsec=frontcover&source=web&ots=xTDnBwSGHF&sig=tbXe2xyO1LGmqGwTA1v1rUgpFx4#PPA519,M1

    Comment by Joseph O'Sullivan — 4 Sep 2007 @ 3:25 PM

  349. Wayne, that’s a fascinating article.
    http://www.fysik.lu.se/eriksw/aoe2001/EOS_AOE2001_Leck.pdf

    I’ll quote a bit:

    “To test the idea that the tiniest aerosol particles
    are made of sulfuric acid, they were examined
    by electron microscopy during the 1996 Arctic
    expedition. It turned out that these very small
    particles,when present,were not at all composed
    of sulfuric acid. Instead, they were
    mostly five- or six-sided insoluble solids, resembling
    viruses,and were accompanied by larger
    particles such as aggregated compact balls,
    bacteria, and fragments of diatoms [Leck and
    Bigg, 1999; Bigg and Leck, 2001; Leck et al.,
    2002].The most likely source for these particles
    is the open water between ice floes. If these
    “virus-like”particles, already in sizes 20–50 nm
    in diameter, rather than tiny sulfuric acid particles,
    served as cores for subsequent condensation
    of DMS oxidation products, then the
    growth process to cloud-forming particles
    would be greatly shortened and all the action
    could take place below cloud base. Such a
    mechanism would remove the need for
    formation and growth of aerosol particles
    above the clouds.The simple system proposed
    prior to the 1991 and 1996 Arctic expeditions
    became suddenly more and more complex….”

    Comment by Hank Roberts — 4 Sep 2007 @ 3:29 PM

  350. Jamie, you asked if any models have shown such sudden drops; see the prior thread, I pointed to it in an earlier response on Aug. 30, saying “linear extrapolations are more optimistic about sea ice than climate model runs and every model includes some runs that show periods of unusually rapid decline (which get blurred if only the average rather than the extreme cases is looked at). This looks at model runs that look much like this week’s Arctic sea ice.”

    http://www.realclimate.org/index.php/archives/2007/01/arctic-sea-ice-decline-in-the-21st-century/#more-391

    Comment by Hank Roberts — 4 Sep 2007 @ 5:12 PM

  351. RE: #350
    Hank, thanks for the response. In the simulation shown in Figure 1 in the other thread, the mean decrease in September sea ice across the decade was 400,000 square km per year, with a couple of years that seem to approach the ~1 million square km yearly decrease that is likely to result this year. So we could actually be observing an extreme case in the making.

    If the trend this year continues for the next few years, resulting in a mostly ice-free Arctic ocean in the summer, will the rate of global warming accelerate, and by roughly how much?

    Comment by Jamie Cate — 4 Sep 2007 @ 6:33 PM

  352. Jamie, I’m just another reader here like you are. You could look for the threads on “albedo” and the notes in the “Start Here” section will be helpful. Your question assumes all other things held the same and only sea ice changes, I think. I doubt that’s realistic.

    Meanwhile, sea ice continues to decline. Note the definition of “sea ice” here is “at least 15% ice” — not a solid sheet of ice:
    http://www.nsidc.org/news/press/2007_seaiceminimum/images/20070904_timeseries.png

    Comment by Hank Roberts — 4 Sep 2007 @ 7:28 PM

  353. Hank, it is complex (at the core) and yet very simple. Hard to imagine that cold water under the ice Micro-organisms created their own turf protecting scheme, or is it a form of symbiosis between themselves and the ice, in better terms they evolved from the ice and nurtured it in return.
    But several consecutive years of consistent warm polar atmosphere took its toll, perhaps the Russian side had several more leads than usual this past spring.

    Comment by wayne davidson — 4 Sep 2007 @ 10:03 PM

  354. RE: #352 – In my trade, I’ve been trained by wiser people than me, as well as many hard knocks, to be innately suspicious of inflection points. They may actually reveal something that changed, or, may point to an equipment problem.

    Comment by SteveSadlov — 4 Sep 2007 @ 10:12 PM

  355. Re #340

    John,

    That is an interesting question. I had not considered what would happen to the extra heat now being stored in the Arctic Ocean. But it has been mooted that it could lead to more snow in Canada and Scandinavia causing a new ice age. If you think of the ice covering Greenland, and realize that it all originated from water evaporated from the oceans, then it took a lot of heat to produce that two mile thick ice!

    However, IMHO global warming has made the world too warm for snow to lie through the summer, which would be needed for a new ice age, so I will forget about that idea.

    There are two main routes for the heat: first as radiation and second as latent heat of evaporation. The radiation will be partly trapped by CO2, but to a greater degree by the main greenhouse gas water vapour. Without the sea ice, it is much easier for the ocean to produce water vapour so increasing the greenhouse effect.

    With more water vapour you also get more clouds, and the greatest greenhouse effect is caused by clouds. They block the radiation across the whole OLR spectrum, and can keep night time temperatures very similar to those of the day. The polar night lasts six months, so Arctic temperatures could hover around 0C all winter. The had rain in Svalbard in winter for the first time ever last year.

    What I think will happen is that the Arctic will remain warm while Canada and Siberia cool. This will cause winds blowing from the continents to the oceans (land breezes.) Will that have a “lake effect” and produce more snow on the Arctic coast? Will the air blowing from Russia pull in warm air from the Mediterranean, and leave Moscow snow free this winter?

    Certainly here in the UK I think we will have a mild winter, and suggest it might be a good idea to sell any shares you have in Scottish and Alpine ski resorts :-(

    Comment by Alastair McDonald — 5 Sep 2007 @ 5:37 AM

  356. Re 338:

    My understanding of the DMS production is that it occurs as the phytoplankton respond to the light and warmth of summer, but I am delighted if someone who knows about this matter would explain if that is incorrect. There is a recent paper on lower productivity in the Bering Sea — that would imply lower DMS production, lower albedo and more warming. I have seen nothing about whether the productivity is falling across the Arctic. If so, there is a simple explanation for the melting ice.

    The link at ref mentions skimming the surface layer for various things including surfactants. I have found no further information on the latter, particularly about whether the surfactants were all natural or whether synthetic surfactants and anthropogenic oil sheen have made it so far north. If so, the sequence is clear: more surfactant/oil sheen suppresses bubble formation, reduces CCN and decreases albedo. The ice melts. More fresh water at the surface reduces mixing, lowers nutrient levels and reduces productivity some more.

    Essentially, I am proposing an interference at a crucial point in the feedback mechanisms, particularly a disruption of those biological feedbacks which are so much more powerful than mere physics. The physics of higher Weber numbers with falling surface tension is a complication which could go either way — too low and CCN numbers would increase as colliding droplets breakup, but my guess would be for the number to mainly fall in the coalescent range, reducing albedo further.

    Robert Essenhigh has suggested that an ice-free Arctic will powerfully feed back cooling from greatly increased snowfall over the northern hemisphere. If the oilsheen/surfactant hypothesis is correct then this feedback is being interrupted and we are sailing uncharted waters.

    JF

    Comment by Julian Flood — 5 Sep 2007 @ 7:25 AM

  357. Does anybody know the last time that the arctic ocean was essentially ice free?

    I have seen some press articles stating that it has been over a million years.

    However, I can not find anything like a science journal article on the subject.

    The Eemian was only 125,000 years ago, but was it warm enough for an mostly ice free arctic?

    Would think that ocean deposits would provide needed data, but obtaining them in shifting sea ice would be difficult.

    Thanks

    Comment by Andrew — 5 Sep 2007 @ 9:23 AM

  358. re: #355 Alastair
    re: sell stock in Scottish & Swiss ski areas

    [THIS IS NOT INVESTMENT ADVICE. JUST A COMMENT].

    Well, at least the Scots will get those nice wineries to replace the ski areas.

    In Switzerland, the banks already aren’t lending to ski resorts under 1500m, and various reports expect pressure on the resorts around Switzerland. Hence, investment in an increasingly-scarce resource (the higher slopes, which will last a fairly long time) may actually be a good investment.

    Comment by John Mashey — 5 Sep 2007 @ 9:31 AM

  359. Andrew–Putting a phrase fromyour question into Google
    “arctic ocean was ice free”
    turns up this link among quite a few others you might look into:

    Ocean Drilling Research:
    From these four cores we can conclude that from at least 73 million years ago to approximately 45 million years ago, the Arctic Ocean was ice-free …
    http://books.nap.edu/openbook.php?record_id=9463&page=1

    Comment by Hank Roberts — 5 Sep 2007 @ 9:51 AM

  360. Who can now prove, OR is ready to bet 1000$, that Arctic will not be ice-free in 2008 – next year?

    Comment by FredT34 — 5 Sep 2007 @ 12:37 PM

  361. Overpeck et al “Arctic System on Trajectory to New, Seasonally Ice-Free State” (Eos, Vol. 86, No. 34, 23 August 2005) states: “There is no paleoclimatic evidence for a seasonally ice free Arctic during the last 800 millennia.”

    73-45 million years ago was the Cretaceous, there are fossil records of animals like Crocodiles living within the Actic Circle, I referenced a paper about that period in #317 – the abstract is worth reading.

    #354 SteveSadlov,
    I keep going back and trying to find a reason not to see this as indicative of a fundamental change in the Arctic ice-sheet. I keep failing.

    Comment by CobblyWorlds — 5 Sep 2007 @ 1:23 PM

  362. RE: Scottish ski areas. Well, here in California, investment continues apace. The biggest problem is a people problem. Most people here live in very temperate coastal and lowland areas. Once you get past February, the weather in such areas improves to the point where people, for the most part, start to forget about the snow in the more highland / inland areas. So, as a result, ski areas here make or break based on what they can do in astronomical winter. We have wonderful spring skiing. Very uncrowded. If the ski operators ever figure out how to inexpensively remind people that March – May can be as good as or better than Nov – Feb, then they will clean up. As it stands, they are gambling a bit with their expansions, things will definitely get a lot more competitive.

    Comment by SteveSadlov — 5 Sep 2007 @ 1:31 PM

  363. #360 Fred T34,

    I certainly can’t afford $1000 given my latest pay award (pitiful). But I’ll bet The Arctic Ocean won’t be ice free (no area >15% concentration) at any time in 2008.

    My forfeit? I’ll end all of my posts here with the tag-line: “But I’m a complete donkey, so what do I know.” If you’ll do the same in the event that you lose the bet. ;)

    Comment by CobblyWorlds — 5 Sep 2007 @ 1:44 PM

  364. FredT34, you can probably find takers on that, if you’re wagering.
    http://www.longbets.org

    Comment by Hank Roberts — 5 Sep 2007 @ 2:10 PM

  365. Re: 360

    You would probably lose your bet.

    The multiyear ice has piled up against greenland and is 5 meters thick.

    The is the exact area where the Danish is trying to figure if the Lomonosov ridge joins Greenland, so they can claim (or coshare with Canada) the North Pole, under the Law of the Sea Convention.

    Anyways the Danish Vessel ODEN could not proceed as it got within a few hundren KM of Greenland, due to the thick 5 meter ice.

    Now the ice in the rest of the arctic is thin and full of holes and melt ponds.

    Now if you bet that the North Pole would be ice free in 2008, you might have a small chance of winning in 2008

    Comment by Larry — 5 Sep 2007 @ 2:29 PM

  366. Re #360 et al.

    I agree with Larry that north of Greenland there will still be some ice next year. But if you still want to place a bet try James Annan:
    http://www.realclimate.org/index.php?p=161

    Make sure you know what you are agreeing because he is not stupid. He has a PhD.

    Comment by Alastair McDonald — 5 Sep 2007 @ 4:13 PM

  367. RE: #361 – You seem a bit confused between sea ice and continental glacial ice. What we are talking about in this thread is the former – it freezes out of the sea water. The latter is what is on Greenland, and is sometimes referred to in vernacular as an “ice sheet.” In any case, I think what you may be trying to say is, you believe there has been some fundamental change in sea ice behavior. Perhaps. The question for you is, do you trust passive microwave remote sensing? And a subsidiary question, do you trust the processing of raw data from such sensing especially in light of “adjustments” made earlier this year?

    RE: #365 – That is probably the most interesting thing about the current NH sea ice situation. That thickening is a result of three things, wind, the wind’s fetch, and currents. A key set of variables often overlooked in these sorts of discussions.

    Comment by SteveSadlov — 5 Sep 2007 @ 4:33 PM

  368. re: #364 hank
    However, the minimum bet length @ LongBets is 2 years… will have to go to 2009 at least.

    Comment by John Mashey — 5 Sep 2007 @ 5:11 PM

  369. Re 319 (negative feedback)

    Definitions of negative feedback with respect to a metastable state are intuitive but not very general, because there’s no guarantee that such a state exists or can be identified. A more conventional definition of a negative feedback – consistent with both engineering and climate science – would be a response to a disturbance that opposes the initial disturbance.

    A first-order negative feedback system does tend toward a stable state, but when the dynamics are more complex, a pure negative feedback system can be unstable, as 306 points out. Consider a shower in an unfamiliar hotel … hmm, a little cold, turn the knob … too hot now … turn the other way … ooh, freezing … other way … ow! Pure negative feedback, turned unstable by dynamics (the delay in the pipe). One quickly learns that it’s better to be less aggressive with the taps, that is, it’s better to be overdamped.

    Tom

    Comment by Tom Fiddaman — 5 Sep 2007 @ 5:45 PM

  370. Hey, he can bet that 2009 will be the _second_ year in a row with a complete Arctic Ocean melt (grin). I just want to see him put up the money there and watch the crowd respond.

    Comment by Hank Roberts — 5 Sep 2007 @ 5:46 PM

  371. Browsing through an ancient volume of Science (March 16, 2007), I encountered this passage regarding what the models have to say:

    Our analyses show that in the IPCC AR4 models driven with the Special Report on Emissions Scenarios (SRES) A1B emissions scenario (in which atmospheric CO2 reaches 720 parts per million by 2100), a near-complete or complete loss (to less than 1 x 106 km2) of September ice will occur anywhere from 2040 to well beyond the year 2100, depending on the model and the particular run for that model. Overall, about half the models reach September ice-free conditions by 2100 (32).

    Now I’m a complete donkey, so what do I know… but from my asinine perspective, it’s astonishing how quickly these models (possibly the ultimate achievement of computer science) are getting shredded by observations.

    Comment by Daniel C. Goodwin — 5 Sep 2007 @ 6:03 PM

  372. Re #368

    Daniel you are absolutely correct.

    Comment by Alastair McDonald — 5 Sep 2007 @ 6:10 PM

  373. Here’s something sort of off topic, sort of not. Anyone here have any thoughts about Wrong Way Flanagan? (Hint – boat …. trapped ….. ice).

    Comment by SteveSadlov — 5 Sep 2007 @ 6:11 PM

  374. A generaliztion:

    Is the primary concern limited to hopw much ice will melt?

    We are programmed creatures of the visual so meltback is liktly the extent of what we canr elate to.

    Asking the larger questions: impact on Western North American precip and temperature ranges during the next winter wheat season; or, where will the massive heat influx to the Arctic atmosphere go when the open ocean freezes—- seems too complex to grapple.

    Rather, we awould like to know more before we wager a bet on 2008 meltback.

    Where are we really when we face the most compelling evidence of AGW?…looking for a safe wager.

    Comment by John L. McCormick — 5 Sep 2007 @ 7:02 PM

  375. Re #367
    2040 is presumably from Holland, Bitz and Tremblay, discussed here:
    http://www.realclimate.org/index.php/archives/2007/01/arctic-sea-ice-decline-in-the-21st-century/#more-391
    Mentioned several times above.

    I tried to post updates of Bitz’s RC plots showing the current extent, but mods rejected (copyright I guess). Yes, it does begin to look like even the most pessimistic model projections will be wrong, but early days yet. That tends towards confirming a long-standing suspicion. Climate modellers used to being beaten about the head by sundry nit-picking contrarians might lean ever so slightly towards conservatism – in both model design and parameter choices. Compounding tiny conservatisms could lead to significant under-prediction in a complex modelling exercise. There’s already other tenuous evidence in that direction (vis sea level predictions).

    RC should invite Cecilia Bitz back to comment, once the September mean ice extent is in.

    Comment by Glen Fergus — 5 Sep 2007 @ 7:50 PM

  376. Yes, ice models got it wrong, but have they been programmed to integrate “hot” Polar Anticyclones? I have seen 2 such phenomenas in the past 25 years (North American side only), in 2007 and 2005, it is stuff that is not even in the text books, let alone programming. I think we must go beyond the computer code competence debate and focus on the reasons why its +30 C in Northern Quebec when there is still snow and ice on the lakes while further South it was +15 C! My best guess, and for lack of a complete rack of data to plunder, its the upper Polar atmosphere which was warmer, given a stable anticyclone which warms up abnormally warmer descending upper air. Looking at Cryosphere Today animation and at NSDIC cloud cover report:

    ttp://nsidc.org/news/press/2007_seaiceminimum/images/20070822_cloudanomaly.png

    It is highly likely that there was a similar stagnant High Pressure North of Alaska in June. Anticyclones usually give colder weather in the Arctic, so this is perhaps something definitely to study, when the surface (white snow covered ice) is not the primary source of heat and melting occurs.

    A sunset today towards the Arctic Ocean Open water was quite early, by 5 to 10 minutes, this strongly suggests an extreme lower troposphere which is unusually warm to the West of 74 43 N 94 57 West , the Upper air sun oblateness is a little more normal above the horizon, slightly warmer than last yea at this time.

    Comment by wayne davidson — 5 Sep 2007 @ 11:23 PM

  377. Thanks much, Glen Fergus (#375), for providing the attribution and the link (as I should have done). Regarding plots of the current extent, I am also grateful to someone a couple of hundred posts ago who shared the Cryosphere Today link.

    http://arctic.atmos.uiuc.edu/cryosphere/

    The materials there are exceptional in terms of graphically conveying what’s going on at the ends of the earth.

    But Glen, in any other profession (even computer science, where practitioners are accustomed to compounding innaccuracies) “ever so slightly” would connote a near miss. It should be clear by now that the models are missing quite badly. 2040 minus 2007 (the date of AR4′s publication) is 33 – when the correct answer is probably closer to 3. That’s off by an order of magnitude.

    The public consequence of this degree of inaccuracy, whatever social causes may have factored into it, is that leading climate scientists have contributed to the perception that AGW is something we don’t need to worry about for another few decades. Granted, this is an absurd conclusion from the IPCC report as written. But it’s a conclusion many people have arrived at, nevertheless. If this has happened because scientists have been “beaten about the head” as you suggest, then one has to conclude that such forms of persuasion have proven quite effective in this instance.

    Comment by Daniel C. Goodwin — 6 Sep 2007 @ 12:19 AM

  378. It turns out the passage I quoted in post 371 above is not from Holland, Bitz and Tremblay, but from a review (a pretty good one) in the “Polar Science” issue written by Serreze, Holland, and Stroeve.

    http://www.sciencemag.org/cgi/content/abstract/315/5818/1533

    Sorry for the inconvenience (which is God’s final message for mankind, according to saint Douglas Adams).

    Comment by Daniel C. Goodwin — 6 Sep 2007 @ 12:46 AM

  379. #375: Are the models wrong?

    Current sea ice extent is 4.42 km^2. Add this data point to the red curve on figure 2 of the page you linked to (the red curve correspond to actual observations while the other 7 are simulations), and the red curve still looks like an 8th run of the same set. Curve number 8 is low but doesn’t stand out. And, even when the model is perfect, there is still a 12.5% chance that the observed run is the lowest one of the ensemble.

    12.5%… To me, this means that, most likely, the model is missing something significant.

    Well, for the last few years reality has been at the low end of or below simulated runs. So now we have the actual data of those last few years, and it’s just a matter of understanding it…
    I would be interested in hearing climatologists’ conjectured explanations and how they plan to check those conjectures. So. Some conjectures I’ve seen on this thread.
    - phytoplankton
    - virus-like”particles, biological feedback
    - “hot” Polar Anticyclones
    -” it all started when we lost the overall ice thickness and mass between 1989 and 2000. This loss occurred without the benefit of the albedo feedback. The mechanism for this loss has not been explained or understood to my knowledge. “— is this true? It at least points to a direction on which to focus

    Did I miss other proposed explanations?
    Are there any other guesses as to why simulations and observation are probably in disagreement?

    Comment by Also horrified — 6 Sep 2007 @ 2:27 AM

  380. Calculate this carbon footprint and tell me if I have a problem. My neighbor owns these vehicles and I am truly disgusted.

    1972 Chevy Blazer K-5 454
    1996 Chevy Suburban 2500 454
    2006 Ford F-450 Powerstroke 6.4 Liter Diesel
    2006 Audi RS4
    2000 Porsche Targa
    1996 Buick Roadmaster 5.7 Liter(he says)
    2005 Hummer H2

    What is the damage here?

    Comment by Brendan Kennelly — 6 Sep 2007 @ 2:43 AM

  381. Steve #367,

    I’m only confused by why you think me confused.

    Overpeck clearly refers to the ocean ice sheet as you would not get an Arctic seasonally free of glacial ice – glaciers take >1 year to come and go. My reference to the Cretaceous was to add to a poster who had referred to it above.

    I did see the animated gif referred to earlier with regards changes to datasets. But I’m not a professional, so I have to rely on the professionals, if people like NSIDC retract this years data then I will (with relief) change my opinion appropriately. I am not qualified to second guess. However Peter Wadhams earlier this year was talking about the possibility of an ice free Arctic by 2020 due to findings on ice-sheet thickness, with NSIDC staff saying it was unlikely. All that was before this melt season. I await their opinions on that with interest.

    But if Serreze was saying in March that we might be near a change in behaviour:
    “When the ice thins to a vulnerable state, the bottom will drop out and we may quickly move into a new, seasonally ice-free state of the Arctic… …I think there is some evidence that we may have reached that tipping point, and the impacts will not be confined to the Arctic region.”
    Then where does this melt place us, further away from any such transition point?

    The impact of weather on the ice can generally be viewed as a random factor, any trend in weather may be down to AGW and local changes, so it’s hard to say what trends will continue. In any case as we have seem this year, a particular “weather event” can still have an impact that creates such changes they are likely to affect following years, and indeed the overall trend.

    Perhaps the next few years will see an unexpected cooling – but I wouldn’t place and climb a ladder on the assumption that if I fall I’ll have a soft landing.

    Comment by CobblyWorlds — 6 Sep 2007 @ 3:00 AM

  382. Hi Brendan. Some just can’t seem to ever get satisfied. At this point he should diversify and get a large boat or an airplane (both nice ways to burn fuel and spend money).

    However, purely from the emissions POV, it’s better to have all of these vehicles owned by the same guy, who can use only one at a time, than have each one of them owned separately (and therefore all used concurrently). Think about it, each one of these cars spends probably over 95% (likely over 97% in fact) of its time parked, which is a good thing.

    Comment by Philippe Chantreau — 6 Sep 2007 @ 9:16 AM

  383. #380: well, your neighbor can have as many cars as he likes, but he can only drive one at a time, so it doesn’t relly matter how many cars he has: at any time at most one of them will be on the road polluting, and the others are just pieces of metal sitting there like tree stumps.

    Comment by Also horrified — 6 Sep 2007 @ 9:26 AM

  384. Re #380, 382:

    Each vehicle takes energy to make. As a rule of thumb, 10% of the total energy used by a car goes into making it and 90% into driving it. A person with 6 lawn ornaments and 1 useful vehicle is still making 60% more CO2 emissions than someone with just 1 useful vehicle, assuming those lawn ornaments get scrapped at about the same rate as regular vehicles.

    The vehicles also need to be stored somewhere. In the best case they’re just left sitting on the lawn, costing no resources. What is more likely is that they are on some sort of pavement (concrete being a major source of CO2), perhaps even in a garage.

    Beyond the CO2 aspect, those cars represent a lot of wasted resources in a world with a lot of needy people.

    Comment by Robert Edele — 6 Sep 2007 @ 9:48 AM

  385. Brendan, the “carbon footprint” is calculated from _fuel_use_.

    If he sold them, would they be used more than if he keeps them?
    A lot of us right now are in this transition, with internal combustion engines on vehicles we have long owned, use intermittently, and can’t replace yet. Come back and post your total gasoline, electric, and natural gas use per year and how you’re reducing it. That fuel use is your carbon footprint.

    The single cheapest way to quit being disgusted is to improve your own behavior and be a good example.

    Comment by Hank Roberts — 6 Sep 2007 @ 9:50 AM

  386. off topic regarding the cars:

    manufacturing and transporting a car are very energy intensive … I’ve heard numbers in the 50% range … in the live of the car, 50% of all emissions are due to the manufacturing process. Having 7 is not the same as having 1.

    Comment by John P. — 6 Sep 2007 @ 10:08 AM

  387. Does anyone here have numbers on sea ice area more recent than 28th August? Or access to the daily numbers charted in the graphs at Cryosphere Today? It looks as if area has levelled out at 3M sq km, while the NSIDC site shows the extent is still dropping. Both are around 60% of the 1979-2000 average for this date.
    My impression is that in a typical year the core ice pack would be at 100% concentration, and melt around the edges would mean that the whole extent had 70% ice cover. This year, we’re down to just the core ice pack, and that’s at 70%. As others have observed, there is thick ice north of Greenland, and the rest is thin and melting.
    My entirely amateur prediction is that the freeze will go slowly, winter ice area will be a record low around 10-11 M sq km, there will be late-winter rain in Svalbard, and a record low and early start to the melt season in March. Where it goes from there depends critically on the winds and currents in the spring and early summer, and what they do to this core multi-year pack north of Greenland. Some of it will flush out down the east coast, as it does every year. But how much. The rest will all melt. Anyone up for a sweepstake on the date for the NWP opening in 2008?

    Comment by Nick Barnes — 6 Sep 2007 @ 10:36 AM

  388. John, look at the graphics (recent topic in “Open Mind” — see the link on the right hand column under “Other Opinions”). There are so many different measures that it does help to look at them as graphics, and Tamino is just now collecting that information in one place.

    Also of course see http://www.globalwarmingart.com/

    Those may both be listed also under the “Start Here” link.

    Comment by Hank Roberts — 6 Sep 2007 @ 12:10 PM

  389. Re #386:
    “manufacturing and transporting a car are very energy intensive … I’ve heard numbers in the 50% range … in the live of the car, 50% of all emissions are due to the manufacturing process.”
    – John P.

    Motor gasoline usage in the USA is nearly 10 million barrels per day (according to the EIA, http://www.eia.doe.gov). This is about 50% of all oil consumed by the USA and about 20% of all energy consumed by the USA. The manufacturing sector uses about 32% of all energy used in the USA, so I really doubt if auto manufacturing alone uses 20%.

    Comment by Robert Edele — 6 Sep 2007 @ 2:24 PM

  390. Many here will already know this, but folks should be aware that Steve Sadlov is a denialist who often just makes stuff up.

    Re #298: Paul Ehrlich suggests “Arbustocene” as an alternative to Anthropocene.

    Comment by Steve Bloom — 6 Sep 2007 @ 2:40 PM

  391. Well the Canada Ice Center has come out with a report of ice conditions for the Canadian Arctic.

    Update on the Canadian Arctic

    The report has some information information, but their appears to be some caution on declaring the arctic ice in the Canadian Arctic at a minimun.

    At the end, their is an intersting writeup on how Cryosphere Today tends to underestimate ice concentration, for low concentrations of ice.

    Regardless, Global warming knows no national boundary, and if you draw a straigt line from Alaska thru the North Pole to Russia, you will see that most of the Ice favors the North American side anyways, due to winds and Arctic currents.

    Im actually amazed that their is not more ice in the Canadian Arctic, but it appears that the arctic ice, being pushed in is melting out before it can clog the shipping channels of the sourthern portion of the Canadian Arctic.

    Environment Canada has also that no new ice will start forming until the last week of September in their 30 day ice forecast.

    Comment by Larry — 6 Sep 2007 @ 3:47 PM

  392. Re. #386 and #389, the peer reviewed studies that have been done on the subject put the percentage of a car’s lifecycle emissions that are due to the combined manufacturing and disposal processes at around 15%, the other 85% being due to the vehicle’s operation. E.g. see MacLean and Lave .

    Comment by Dave Rado — 6 Sep 2007 @ 5:05 PM

  393. RE: #391 – “At the end, their is an intersting writeup on how Cryosphere Today tends to underestimate ice concentration, for low concentrations of ice.”

    I agree. I also suspect NSIDC have similar issues. It may be an artifact of the whole passive microwave paradigm.

    Comment by SteveSadlov — 6 Sep 2007 @ 8:06 PM

  394. RE: #390 – Wrong Bloom. I am a responsible, scientifically informed environmentalist. I want facts. Science. Numbers. Accuracy. I abhor politics, blather, hype, feelings-based decision making, etc. Is it too much to ask?

    Comment by SteveSadlov — 6 Sep 2007 @ 8:11 PM

  395. Re #394: Oh there is ever so much evidence. We could start with the recent thread over at RP Sr.’s blog where you started out claiming the Arctic sea ice trend was being influence by Siberian dams, falling back on Siberian river diversions afer it was pointed out that there aren’t any dams, falling back on fact-free questioning of Soviet-era precip figures after it was pointed out that there aren’t any river diversions, and finally just disappearing in a puff of smoke. Will you link that or shall I? But really, all one has to do is read up this thread to see several instances of your wishful thinking.

    Anyway, I don’t especially care about this stuff since I’m obviously well aware of your habits. What concerns me is that someone new to this site might believe one of your factoids.

    But why don’t you just nip the problem in the bud and stop, at least on this blog? Obviously you’ve got free reign to say whatever you want over at Climate Audit where it doesn’t do any harm. I don’t see why that shouldn’t suffice.

    Comment by Steve Bloom — 6 Sep 2007 @ 9:31 PM

  396. Thanks for the Canada Ice Centre report Larry, very interesting. If anything it makes me more pessimistic about the near term future of Arctic sea ice, the dramatic reduction in multi-year ice and its description as ‘rotten’ should make for an interesting few years!

    Comment by Phil. Felton — 6 Sep 2007 @ 10:20 PM

  397. Sadlov,

    You seem to claim on CA that all of the ice is being forced, by currents and prevailing winds, up against Greenland. However reports from that area seem to say that the ice is 5m thick. I would think that given the amount of ice you say is being carried there that the ice would be much, much, thicker. But, it doesn’t seem to be. How do you explain that?

    Citing Canadian ice reports (or even NOAA ice reports for the Arctic Ocean), which you claim that crabbers rely upon — NOT! mainly because they fish S of the Bering Strait along the Western Coast and Alutien islands… The advisories out of Anchorage are advisories for mariners, but I find it hard to think of any commercial fisherman (maybe native whalers) who venture into that part of the arctic.

    Please note that the Canadian ice reports mainly relate to the area between the Canadian mainland and Greenland. This is an important area, but it is hardly the entire arctic ocean. Your constant weather reports do not provide a whole picture of the ice extent in the arctic. You should be more inclusive in your reports — even the maps that you link to show a severe loss of sea ice extent. Just what do you think is happening up there?

    Comment by John Sully — 7 Sep 2007 @ 12:17 AM

  398. #391 Nansen correctly used vectors in order to explain ice movement, currently there is an was a High pressure system in the SW quadrant of the North American Pole sector. Combine this with the Arctic Ocean Gyre, and you get a stronger gyre circulation overriding the Southwards Canadian Archipelago 2 nm a day channels current . ….

    With retrospect, models themselves may give a clue of what just cause this massive extra ice melt. RC readers may recall Polar Amplification Article:

    http://www.realclimate.org/index.php/archives/2006/01/polar-amplification/

    Of which several dozen GCM’s forecasting distant in the future Polar ST’s equal with current temperatures in the Arctic, the projections were inaccurate temporally, but were very accurate with respect to the trend direction (severe warming). This goes likewise with Met Office Ice coverage projections (again off by several decades), this probably means that the common denominator between Polar amplification models and Ice extent projections (despite different GCM codes) is more am atmospheric trend calculation error rather than sea temperatures , even if sea and atmosphere are severely intertwined, its probably easier to model sea temperatures since they don’t change as quickly as the air, and this years melt was driven by High pressure cloud free weather.

    Comment by wayne davidson — 7 Sep 2007 @ 3:11 AM

  399. and this years melt was driven by High pressure cloud free weather.

    Naive question: is the presence of high pressure, cloud free weather an incidental or is it a consequence of past warming?

    Comment by Jeffrey Davis — 7 Sep 2007 @ 8:51 AM

  400. Does anyone know the age of the physical ice itself in the oldest multi-year ice in the arctic? (I’m not looking for the age of the multi-year ice phenomenon, but the age of the actual ice) In 2007, in addition to young ice, have we been melting off multi-year ice that is tens, hundreds, or thousands of years old? Likewise, is the remaining multi-year ice north of Canada and Greenland a few years old, 10 years, or hundreds?

    Another question: how long does it take to grow 3 to 5 meter thick multi-year ice?

    Comment by KG — 7 Sep 2007 @ 10:48 AM

  401. Jeffrey, it’s a longterm variable. Look for info on
    Arctic and North Atlantic Oscillations (AO/NAO)

    Comment by Hank Roberts — 7 Sep 2007 @ 10:50 AM

  402. RE: #395 – RE: Siberian river impacts / salinity – the truth is, as I stated here previously and over on other blogs, it’s an area warranting further study. That has been and remains my point. Try as you may to pigeonhole me into some politcal category you may have, the science is what it is, and the gaps in the science are what they are. If you deny this, then, you are anti science.

    RE: #397 – I am confident that since 1979, there has indeed been a trend in sea ice extent reduction at summer minimum. Prior to 1979, there are some real challenges with data. By the way, 5m thick ice is a formidible thing. It that as thick as it gets, obviously not. But it’s nothing to sneeze at either.

    Comment by SteveSadlov — 7 Sep 2007 @ 11:01 AM

  403. Re #398
    Wayne,
    I have identified the error in the atmospheric trend calculations. The OLR scheme used in all the GCMs (they all use roughly the same scheme) is wrong. Put simply, it is based on the idea that the forcing from greenhouse gases originates high in the atmosphere. In fact the greenhouse gases absorb in the bottom 30 m of the atmosphere. It is this warming of the air adjacent to the ice which is causing it to melt.

    The skeptics have pointed out this error, but claimed that since the the greenhouse bands are saturated increasing CO2 cannot cause global warming. What they are missing is that as CO2 increases the saturation happens closer to the ground. This causes surface ice to melt, reducing planetary albedo, and so CO2 indirectly causes global warming.

    Of course, any criticism of the models by the skeptics has been shouted down very loudly, as no doubt will this post if it appears.

    Comment by Alastair McDonald — 7 Sep 2007 @ 11:21 AM

  404. *Also Horrified #379,

    On it’s own a 12.5% difference on a timescale of 1 year would not undermine the models, 1 year is weather, not climate, and nobody says that the climate models do weather. The key issue is that of ice thickness which is a consequence of age, the older the thicker. It’s the loss of perennial ice starting with the behaviour of the Arctic Oscillation that has so weakened the ice sheet that we now might be facing an ice-free summer Arctic Ocean much earlier than modelled.

    The mechanism for the loss of perennial ice in the 1990s has been identified, it was the Arctic Oscillation (AO), read more on this page: http://www.jisao.washington.edu/ao/

    Now if you look at a plot of the AO: http://www.arctic.noaa.gov/detect/climate-ao.shtml you’ll see it was a period dominated by low pressure over the pole, or a +ve AO index. And if you look at the message below (to Larry) you’ll see a link to a paper. Figure 3 of that paper shows how in 1989 there was a change in the ice area(and extent) from 1989, and going back to that plot of the AO you see it’s strongly positive for some years after 1989. For a more detailed monthly plot of AO see the bottom of this post.

    So yes the AO behaviour in the 1990s did pre-condition the whole sheet to where it is now. The only one of your list I wouldn’t reject as having a big role in what we’re seeing is the polar cyclones, don’t know enough (yet) to make an intelligent comment.

    If we are at a transition point in ice sheet behaviour caused by a loss of the integrating (time averaging) effect of old ice, then I don’t think modelling will be useful over decadal timescales. The good news is that by 2100 the modellers will have the data they need to make skillful models of icesheets. ;)

    *Larry #391,
    I too can heartily recomend the link you posted.

    Sourced from that pdf, here’s another: “Variations in the age of Arctic sea-ice and summer sea-ice extent.”
    Rigor/Wallace GRL 2004.
    http://seaice.apl.washington.edu/IceAge&Extent/Rigor&Wallace2004.pdf
    That’s well worth reading. Doubtless there’s other good stuff at the end of the links in that Environment Canada pdf.

    *Jeffrey Davis #399,
    I don’t know, but it doesn’t sound like a naive question to me. You can see a detailed plot of the AO here: http://www.cpc.ncep.noaa.gov/products/precip/CWlink/daily_ao_index/month_ao_index.shtml The red, +ve anomalies relate to high pressure north of 20deg.

    Comment by CobblyWorlds — 7 Sep 2007 @ 11:28 AM

  405. This is off topic as my comments usually are, but I can’t resist.

    #394 (SteveSadlov): “Wrong Bloom. I am a responsible, scientifically informed environmentalist. I want facts. Science. Numbers. Accuracy. I abhor politics, blather, hype, feelings-based decision making, etc. Is it too much to ask?”

    From the “The Human Hand in Climate Change” RC post earlier this year:
    #60 (Steve Sadlov) environmentalists were “recruited by the KGB during the late 1960s and early 1970s to undermine Western strategic defenses.”

    Comment by Joseph O'Sullivan — 7 Sep 2007 @ 11:37 AM

  406. Sorry for the OT, but since Bloom dragged me down into the mud …. ;)

    Since we are (or at least I am) open kimono here today, allow me to share my actual politics, just so we can move on once and for all from the subject. I am a former Trotskyite. Currently, I mix and match. Take a dab of JFK-ism, mix in some Reaganism. Add a dash of Disraeli. Season with Churchill. Bring to a boil. Top off with a bit of John Jay. Allow to cool. Garnish liberally with Jeffersonian Democracy. Serve.

    OK Bloom, your turn.

    Comment by SteveSadlov — 7 Sep 2007 @ 11:57 AM

  407. RE395

    Oh go on, post the link! I enjoy a good laugh…

    Comment by mark s — 7 Sep 2007 @ 11:59 AM

  408. FYI:

    http://aasi-campaign.gsfc.nasa.gov/processstudy.htm

    Comment by SteveSadlov — 7 Sep 2007 @ 12:28 PM

  409. re: 406

    Add a dash of Disraeli. Season with Churchill. Bring to a boil. Top off with a bit of John Jay. Allow to cool.

    You’re a cannibal?

    Comment by Jeffrey Davis — 7 Sep 2007 @ 2:48 PM

  410. With regard to KG’s question about the age of the ice (#400), the first figure in this report referred to by Larry gives a good idea, basically not much as old as 10 years anymore (most

    Comment by Phil. Felton — 7 Sep 2007 @ 5:26 PM

  411. Please allow me to come back on this (provocative) #360 2008-bet topic. Should I understand nobody here can scientifically proove (you know, using some Popper’s Falsifiability) that it won’t happen? Such a bet was just not conceivable only two years ago, in 2005. Reality now makes all of us consider that Arctic Collapse can really happen, say, by 2015 – right now, more people would probably bet on 2015 rather than on 2080!

    So, I feel that Models Collapse has already happened… this year. Events don’t follow a linear curve these days… so, the next question should be: which credit can be given to other predictions on THC evolution or Greenland Ice… as I feel a) they are complex phenomenons, b) data series are short and incomplete… just as the Arctic equation?

    Comment by FredT34 — 7 Sep 2007 @ 5:31 PM

  412. > nobody here can scientifically proove … that it won’t happen?

    Nobody in the sciences will prove that anything won’t happen.
    If you want proof, you want either mathematics, or religion.

    Comment by Hank Roberts — 7 Sep 2007 @ 6:53 PM

  413. Readers here have seen me rant and rave about the importance of marine-freshwater-sea ice interactions and feedbacks as being important to the loss of Arctic sea ice. However, I never posted a cite. Here is one: http://www.acia.uaf.edu/pages/scientific.html Chapter 9 Marine Systems; or, ,http://www.acia.uaf.edu/PDFs/ACIA_Science_Chapters_Final/ACIA_Ch09_Final.pdf

    Comment by Aaron Lewis — 7 Sep 2007 @ 7:39 PM

  414. Sorry I’m a slow learner, it would appear that the ‘less than’ symbol terminates a post!

    With regard to KG’s question about the age of the ice (#400), the first figure in this report referred to by Larry gives a good idea, basically not much as old as 10 years anymore (most less than 5 years old).

    http://seaice.apl.washington.edu/IceAge&Extent/

    Comment by Phil. Felton — 7 Sep 2007 @ 7:53 PM

  415. #403 Allastair,

    30 meters seem a bit shallow, but for your hypothesis to be correct, inversions must weaken all over the world, especially in the mornings with places which have normal days and nights. In the Polar region (the ultimate long day or night) inversions have been mainly weakening as it got warmer, that is a sign that you may be correct. It would be nice to have access to a super computer now and identify the the height were the warming is mostly strengthening.

    In favour of higher altitude warming there is some visual evidence, when the twilights of the long Polar nights are seen brighter (refractive mirror made at the boundary between cold surface and a warmer mid troposphere) , again I suspect that Upper Air data will confirm that the mid troposphere is warming as well.

    This leaves us with the dilemna, where is the code error? It is probably in computer programmed rejections, such as abnormal weather conditions, like “hot”Polar anticyclones, as said before they are hard to explain, yet alone accept. The fact that they exist and appear at random intervals and locations favours the warmer mid troposphere though. Otherwise if everywhere warms at 30 meters at the same time, you would see a more uniform effects. The Polar Ice appeared to have melted more around where there were semi permanent anticyclones, the ice didn’t appear to melt just as much say North of Spitzbergern right by the hottest North Atlantic in years. Please look at

    http://arctic.atmos.uiuc.edu/cryosphere/sea.ice.movie.2007.mov

    The question begs to look back prior to the melt down, taking us to the very location where the last ice remains today, at that same location there was extremely cold weather in March of 2007, -50 C up there, and -46 in Resolute. If there was a continuous warming at 30 meters everywhere, there wouldn’t be this massive meltdown only over the Arctic gyre area but also over the ice next to the archipelago, especially near land, given that the whole Canadian High Arctic had a very warm summer. In March as well, while the Canadian Arctic was freezing really strongly Coastal Siberia had very mild weather, again assymetric conditions which can happen with a warmer mid troposphere, but not with a lower troposphere. Remains to find many other clues given the uniqueness of this extensive meltdown. But you have to explain why there was assymetric melting before convincing that it melted from warmer air 30 m high.

    Comment by wayne davidson — 7 Sep 2007 @ 10:20 PM

  416. Someone had mentioned that they thought the East passage would open this year:

    http://www.natice.noaa.gov/pub/West_Arctic/Laptev_Sea/2007/currentcolor.pdf

    Anyone up for a bet?

    Comment by SteveSadlov — 7 Sep 2007 @ 10:33 PM

  417. There is also a small fallacy in believing that this is a “normal” year, the deadlines for ice minima extent times shouldn’t be the same , 20 September is always used, freezing under the low sun may occur at a later time, the calculation to make would be to find the exact sun elevation when it is not high enough to have any effect. At 30 degrees its hot enough to melt the most frozen snow scape. Now the surface which was once snow on ice is sea water at +4 degrees C…

    Comment by wayne davidson — 8 Sep 2007 @ 12:28 AM

  418. I’ve been lurking here a long time and reading, with interest, the different views. After reading RealClimate, the IPCC reports, and many different sources on the Arctic Ocean and Ice and the Greenland Ice Cap, it seems obvious to me that we have seen a tipping point crossed with respect to the Arctic Ocean. Summer Arctic Ocean Ice after 2015 (my time-series analysis said 2012) would require a change in the other direction.

    Greenland, yesterday, saw religious leaders praying for the glaciers to stop melting. Reported on many online news sites. IMO, the climate reports I read did not appreciate, or at least literally state, the speed of change that could occur on Greenland with the positive feedback of meltwater movement and an exposed, warming landmass. By 2050, the business as usual scenario with fossil fuels will provide the distinct possibility of a Greenland that is, well, pretty green.

    All these reports, and the speculation they bring, are interesting but in facing reality individuals, businesses, and, most of all, governments should consider today where all the water that’s coming from those glaciers will be in a very few years.

    For you and I, we need to remember, that car key in our hand is a dangerous weapon. Think before using it.

    Comment by Mike T — 8 Sep 2007 @ 9:47 AM

  419. http://www.natice.noaa.gov/icefree/FinalArcticReport.pdf

    Comment by Hank Roberts — 8 Sep 2007 @ 10:31 AM

  420. Does this page make these penguins look fat?
    http://science.natice.noaa.gov/images/newbanner.png
    And when did these two start hanging around together?
    http://science.natice.noaa.gov/images/symbol.png

    But seriously, Mr. Sadlov points to last week’s picture; checking this week’s data, it’s cooling a bit, that’s true.

    http://science.natice.noaa.gov/icImages/85_07251_n_12z.png
    http://science.natice.noaa.gov/icImages/cv_07251_n_12z.png
    http://science.natice.noaa.gov/icImages/bs_07251_n_12z.png

    Comment by Hank Roberts — 8 Sep 2007 @ 10:47 AM

  421. RE # 418, Mike T,

    you said:

    [it seems obvious to me that we have seen a tipping point crossed with respect to the Arctic Ocean.]

    Amen.

    You told us what the science community will need 20 years to verify. At which point, what will it matter when they report what you already know.

    I believe what I read and see; and I accept the reality that Artic ice will never return to its pre-1979 state. Now what?

    We would not know a tipping point if it was hitting us in the face.

    Comment by John L. McCormick — 8 Sep 2007 @ 4:20 PM

  422. With the dramatic melting of the Arctic ice this year , even affecting the arctic basin where most of the multiyear ice is to be found I can forsee the arctic being largely ice free by 2012 unless a dramatic reversal takes place .

    Comment by John Locke — 8 Sep 2007 @ 4:24 PM

  423. Hank,

    Thanks for the spelling help, but what I really am looking for is a specific citation of or reason why you believe climate feedbacks are fundamentally different from those in electronics or control systems theory, or even why this would be an important distinction. Nothing I have read indicates this to be the case (apart from non-specific blog assertions without substance).

    Regarding “Hansen’s early work”, would this be the 1984 paper where, “We use procedures and terminology of feedback studies in electronics (Bode. 1945) to help analyze the contributions of different feedback processes?”

    I read this site regularly, and wholeheartedly support it. If you or RealClimate choose to alienate all of the technical engineering folks, so be it. By not using the topic of feedback concepts as opportunity for some cross-discipline understanding, or worse, assert that they are wholly different between disciplines, you perform a disservice to the cause of this site.

    Comment by The Wonderer — 8 Sep 2007 @ 5:43 PM

  424. Instead of relying on these software-generated maps, why not use the polar orbiting MODIS satellites and see the visible picture yourself in real-time (hour or two old that is.)

    http://rapidfire.sci.gsfc.nasa.gov/realtime/

    Comment by John Wegner — 8 Sep 2007 @ 5:46 PM

  425. Alastair McDonald (#403) wrote:

    I have identified the error in the atmospheric trend calculations. The OLR scheme used in all the GCMs (they all use roughly the same scheme) is wrong. Put simply, it is based on the idea that the forcing from greenhouse gases originates high in the atmosphere.

    Its simply radiation balance theory. For the climate system to reach equilibrium, the rate at which energy is leaving the system must equal the rate at which radiation is entering the system. This equilibrium has to be established at the top of the atmosphere where energy is both entering the system in terms of sunlight, leaving the system in terms of albedo, and leaving the system due to the earth’s longwave emissions. The average surface temperature must rise until this equilibrium is reached – simply as a matter of the conservation of energy.

    Alastair McDonald (#403) wrote:

    In fact the greenhouse gases absorb in the bottom 30 m of the atmosphere. It is this warming of the air adjacent to the ice which is causing it to melt.

    I gave you a large body of evidence that reemssion takes place throughout the atmosphere at many wavelengths. (Please see: Part II: What Angstrom didn’t know, comment #555.) Likewise, if water vapor rises, energy will be lost by collisions to thermal emissions by greenhouse gases at any given altitude where it reaches. And given the Maxwellian distribution of kinetic energy and its long tail, collisions will result in thermal emissions which will take place throughout the atmosphere. (See my comment #444 and Ray Ladbury’s #619 in “Part II: What Angstrom didn’t know.”) And for radiation to escape the climate, it must climb through the upper layers. If it is within part of the spectrum which the atmosphere is particularly opaque to, it will be subject to absorption and reemission.

    Alastair McDonald (#403) wrote:

    The skeptics have pointed out this error, but claimed that since the the greenhouse bands are saturated increasing CO2 cannot cause global warming.

    If it were truly saturated at all wavelengths and for all altitudes, then global warming due to additional greenhouse gases could not occur. But the absorptivity of the wings increases as the centerline becomes saturated. But there is line broadening do to pressure and band broadening due to temperature.

    Alastair McDonald (#403) wrote:

    What they are missing is that as CO2 increases the saturation happens closer to the ground. This causes surface ice to melt, reducing planetary albedo, and so CO2 indirectly causes global warming.

    Within that part of the spectra where carbon dioxide would operate at the surface, the spectrum is already saturated due to water vapor – which exists in far greater quantities. Doubling the amount of carbon dioxide where water vapor dominates will be quite neglibible. In fact, this is precisely what A Saturated Gassy Argument was about. However, water vapor drops quite rapidly as the altitude increases, and carbon dioxide plays a very significant role at the higher altitudes even when the center of a given line or band is completely saturated – as the marginal absorption takes place further and further into the wings. This is what Part II: What Angstrom didn’t know was about.

    But you may also want to see what Eli has to say over at his blog.

    Alastair McDonald (#403) wrote:

    Of course, any criticism of the models by the skeptics has been shouted down very loudly, as no doubt will this post if it appears.

    Shout. Shout.

    Comment by Timothy Chase — 8 Sep 2007 @ 6:04 PM

  426. Re #405: Thank you, Joseph. There’s lots more like that to be found for anyone who cares to do a search.

    Re #407: Here ya go, Sadlov in all his glory. Start with comment #73 and read through to the end.

    As I say, what bothers me is not so much that he’s a denialist, but all the evidence-free hand-waving.

    Re #420: Yep, if he keeps predicting it, eventually he’ll be right, and this could even be that time. The problem is that he started with these prognostications at least two weeks ago. It wastes everyone’s time.

    Comment by Steve Bloom — 8 Sep 2007 @ 6:09 PM

  427. This article on events in Greenland this summer quotes some pretty amazing statistics. The associated scientific reports should make for gripping reading. Excerpt:

    ‘Robert Corell, chairman of the Arctic Climate Impact Assessment, said in Ilulissat yesterday: “We have seen a massive acceleration of the speed with which these glaciers are moving into the sea. The ice is moving at 2 metres an hour on a front 5km [3 miles] long and 1,500 metres deep. That means that this one glacier puts enough fresh water into the sea in one year to provide drinking water for a city the size of London for a year.”

    ‘He is visiting Greenland as part of a symposium of religious, scientific, and political leaders to look at the problems of the island, which has an ice cap 3km thick containing enough water to raise worldwide sea levels by seven metres.

    ‘Yesterday Christian, Shia, Sunni, Hindu, Shinto, Buddhist and Jewish religious leaders took a boat to the tongue of the glacier for a silent prayer for the planet. They were invited by Bartholomew I, the spiritual leader of 250 million Orthodox Christians worldwide.

    ‘Dr. Corell, director of the global change programme at the Heinz Centre in Washington, said the estimates of sea level rise in the IPCC report were based on data two years old. The predicted rise this century was 20-60cm (about 8-24ins), but it would be at the upper end of this range at a minimum, he said, and some believed it could be two metres. This would be catastrophic for European coastlines.

    ‘He had flown over the Ilulissat glacier and “seen gigantic holes in it through which swirling masses of melt water were falling. I first looked at this glacier in the 1960s and there were no holes. These so-called moulins, 10 to 15 metres across, have opened up all over the place. There are hundreds of them.”

    ‘This melt water was pouring through to the bottom of the glacier creating a lake 500 metres deep which was causing the glacier “to float on land. These melt-water rivers are lubricating the glacier, like applying oil to a surface and causing it to slide into the sea. It is causing a massive acceleration which could be catastrophic.”

    ‘The glacier is now moving at 15km a year into the sea although in surges it moves even faster. He measured one surge at 5km in 90 minutes – an extraordinary event.’

    Comment by Steve Bloom — 8 Sep 2007 @ 6:25 PM

  428. Related to the arctic sea ice is the fate of the polar bear. The NY Times has a good article on this issue from Andy Revkin. The title tells it all: “Warming Is Seen as Wiping Out Most Polar Bears”.

    An interesting sentence: “The wildlife agency (the Federal Wildlife Service) had to make a determination on the status of a threatened species because of a suit by environmental groups like Greenpeace and the Natural Resources Defense Council.”

    http://www.nytimes.com/2007/09/08/science/earth/08polar.html?em&ex=1189483200&en=42d971c103c46def&ei=5087

    Comment by Joseph O'Sullivan — 9 Sep 2007 @ 1:45 AM

  429. Re #427: there’s a typo in this article, of “year” for “day”. In fact, Ilulissat melts enough water every day to supply London with tap water for a year.
    The Independent has more coverage:
    http://environment.independent.co.uk/climate_change/article2941866.ece

    Comment by Nick Barnes — 9 Sep 2007 @ 2:55 AM

  430. Re #415

    Wayne,

    The 30 m comes from p250 of McIlveen’s “Fundamentals of Weather and Climate.” It refers to both carbon dioxide and water vapour.

    I don’t understand what you mean when you say “inversions must weaken all over the world.” However I might be able to answer your objection by explaining that water vapour plays an important role as a greenhouse gas. It effect depends on its concentration, and the more warming it creates the more water vapour there is. It is driven by a positive feedback. So if you have enough solar radiation and carbon dioxide it will completely dominate the greenhouse effect. This is what happens in the tropics where we see daily storms. Increasing CO2 there will have little effect, and this has been confirmed by Christy and Spencer, and given rise to the tropical lapse rate problem, which has still not been solved despite three simultaneous papers in Science.

    In arctic regions where the surface is covered in ice, water vapour does runaway, because its concentration cannot rise above that of melting ice i.e. 0C. But an increase in CO2 will lead to a raising of the snow line, both in altitude and latitude. That is what we are seeing worldwide.

    You mention “hot Polar anticyclones” and I will try to explain them. In the current models the greenhouse gases produce back radiation and I imagine you believe that this is what is melting the ice. In fact greenhouse gases produce little back radiation since all the energy they absorb gets converted into the kinetic energy of the air molecules. This produces a warm layer of air over the snow surface, and when the sun shines onto the ice it loses some of that energy by thermal radiation and the rest by conduction with the surface air. It this air is warm because the CO2 has absorbed the thermal radiation the snow/ice will melt. Therefore most melting will happen where there are clear skies.

    An important aspect I have not discussed is the part played by clouds, but I will leave that for another post, if you are still interested.

    Comment by Alastair McDonald — 9 Sep 2007 @ 6:44 AM

  431. The Wonderer writes

    in 333: “… a blog is rather ill-suited for resolving such fundamental allegations anyway …”

    and in 423: ‘… If you or RealClimate choose to alienate all of the technical engineering folks, so be it. By not using the topic….”

    I’m just another reader here, not one of the Contributors (see list.

    I think you had it right the first time — a blog is rather ill-suited for resolving questions so important to you.

    It’s a bit overwrought to get upset and think “all the technical engineering folks” share your upset because nobody answered your question to your satisfaction, yet.

    That happens. It’s just a blog. Gavin’s on vacation, last anyone said.

    You’re anonymous, so readers don’t know what you’ve published.

    You could –on your own blog– set out your understanding and invite readers there, where you could put your contribution to the field together in a comprehensive and clear way, and invite readers. If what you have to contribute is publishable you may get a paper.

    Also note the contact information in the ‘about’ link (top of page).

    Comment by Hank Roberts — 9 Sep 2007 @ 12:23 PM

  432. I posted this link in a longer ‘Friday Roundup’ answer but it belongs here:

    Causes of Changes in Arctic Sea Ice
    Wieslaw Maslowski
    Naval Postgraduate School
    ______excerpts_____(lots of illustrations in original)

    “Decrease from 1997 to 2002 …. If this trend persists for another 10 years (and it has through 2005) the Arctic Ocean could be icefree in summer! …
    Challenges for models:
    Inflow of Pacific / Atlantic Water into the Arctic Ocean
    • Pacific Water enters via narrow (~60mi) Bering Strait
    • outflow through Fram Strait prevents Atlantic Water inflow
    • Atlantic Water entering through Barents Sea
    losses* ~98% of heat to atmosphere …”

    *[loses?-perhaps a typo --hr]

    “Increased northward heat flux off the Chukchi Shelf coincides with the sea ice retreat in the 2000s

    “Oceanic forcing can explain ~60% of sea ice melt (both extent and
    thickness) in the western Arctic Ocean ….

    “… NPS model shows significant skill in simulating Arctic sea ice change
    – Model estimates about 33% loss of Arctic Sea Ice during 19972002
    – Earlier model predictions of Arctic Sea Ice melt are possibly highly underestimated
    – Up to 60% of recent decrease of sea ice in the Western Arctic can be due to oceanic forcing:
    – northward inflow of Pacific Water increased inflow of warmer water
    – Less ice allows more solar absorption, which leads to warmer ocean, which in turn will melt more sea ice (the so-called
    ice-albedo feedback)
    – The increased heat fluxes via Pacific/Atlantic Water explain the lack of correlation between sea ice and atmospheric forcing in the 2000s…”
    ——-end excerpt —–

    His last point — great need for far more computing power, to do better modeling.
    http://www.ametsoc.org/atmospolicy/documents/May032006_Dr.WieslawMaslowski.pdf

    Comment by Hank Roberts — 9 Sep 2007 @ 1:37 PM

  433. Alastair

    Inversions occur naturally after a long clear night basically everywhere there is a long clear night. With extra warming originating 30 meters high, from whatever source, inversions would be less steep, this means that it would be warmer overnight. I have seen this trend in total darkness here. Not continuously, but generally weaker inversions.

    The biggest question is try to narrow down why the models can’t mimic current Polar warming trends, generally speaking models succeeded for the world (so far), but not for the Arctic region. This ice melt has all the clues in it, just not found all of them all yet. Clouds play a major role in avoiding a melt every past year, under the ice biology plays a crucial role as well in creating clouds from spring time onwards to end of summer. If the models didn’t include biological and chemical (open leads sea spray) cloud seeding, then that is a major flaw which will need re-integration with current models. But there is more than that, “hot” anticyclones, at least the one in Northern Quebec in April 2005, was forecasted (either by the model or temperatures were corrected by the forecasters), yet anticyclones dominated this 2007 melt. Somehow the ice model from the met office didn’t have this real scenario as a possibility, so I suspect human programming as the source of this error, by limiting the extent of possible clear skies, or by cutting off the possibility of too much heat coming down from above. There is more to it than just that.
    I believe that there is unusual warming in the Uppper atmosphere at a much wider extent
    than before, therefore the chance of having a “hot” anticyclone is greater in the Polar regions, that this warm air is thoroughly mixed almost instantly all the time, but that it is more prevalent in the mid-troposphere, largely undetected by the surface observation network, certainly not picked up by satellites which have trouble differentiating between tropospheric and stratospheric temperatures.
    I give one example of March 3-4 2007 over Resolute, -45 C on the ground when sun disk compressions were “normal” meaning that somewhere in the near horizontal temperature gradient there was warming. not at all extrapolated by GRIB or our local model. hence warm air out there left undetected. This is perhaps the reason why the models fail, it is because reality is not being replicated since it is not being observed.

    I am all ears on your cloud theories Alastair!

    Comment by Wayne Davidson — 9 Sep 2007 @ 3:04 PM

  434. This is the ‘Northeast Passage’ area?
    http://rapidfire.sci.gsfc.nasa.gov/realtime/single.php?T072520930

    Comment by Hank Roberts — 9 Sep 2007 @ 6:44 PM

  435. >”Northeast Passage”
    This is a bit closer I think
    http://rapidfire.sci.gsfc.nasa.gov/realtime/single.php?2007252/crefl1_143.A2007252111000-2007252111500.4km.jpg

    Comment by Hank Roberts — 9 Sep 2007 @ 6:46 PM

  436. Re427 and 429,

    5km in 90 mins! ie 100 years worth of freshwater for London in 90 mins, from one glacier… now i don’t know the precise numbers, but thats not a glacier-size rate of discharge, its more like that of a river!

    I wonder what Correll was thinking when he watched it…

    Comment by mark s — 9 Sep 2007 @ 9:04 PM

  437. RE: 432, Wieslaw Maslowski

    Hank, thanks for posting the link. This is what set me off in post #347. For those who haven’t seen the projections, look at p. 6 in the Maslowski pdf. My jaw hit the floor, and I haven’t quite recovered.

    In the pdf, Maslowski suggests that the Arctic Ocean may be ice-free in the summer within a decade (this prediction was BEFORE the present summer melt, by the way).

    Comment by Jamie Cate — 9 Sep 2007 @ 10:22 PM

  438. On Maslowski’s presentation:
    This is the way the science makes progress. To form hypothesis, collect evidence, create conclusions. So different from the way the denialists proceed.

    It looks like the inflow of warm water into the Artic Sea is related to the increase in the sea surface temperature of the northernmost Pacific starting from 2001 or so.

    http://www.osdpd.noaa.gov/PSB/EPS/SST/climo_archive/anomnight.6.20.1998.gif
    http://www.osdpd.noaa.gov/PSB/EPS/SST/data/anomnight.6.19.1999.gif
    http://www.osdpd.noaa.gov/PSB/EPS/SST/data/anomnight.6.20.2000.gif
    http://www.osdpd.noaa.gov/PSB/EPS/SST/data/anomnight.6.18.2001.gif
    http://www.osdpd.noaa.gov/PSB/EPS/SST/data/anomnight.6.21.2002.gif
    http://www.osdpd.noaa.gov/PSB/EPS/SST/data/anomnight.6.24.2003.gif

    Comment by Petro — 10 Sep 2007 @ 4:31 AM

  439. Alastair writes:

    [[ In fact greenhouse gases produce little back radiation since all the energy they absorb gets converted into the kinetic energy of the air molecules.]]

    Alastair, this is almost word for word Chris Dodd’s pseudoscientific argument that the greenhouse effect doesn’t exist. The elevated kinetic energy of the air means it gets hotter, and that means the greenhouse gases it contains get hotter, and they radiate in all directions, including down. This isn’t just airy theoretical guesswork. The back-radiation from the atmosphere has been measured many, many times.

    Comment by Barton Paul Levenson — 10 Sep 2007 @ 6:09 AM

  440. #336 “…that model still has residual September ice well after 2040. This is where the climate modellers do not seem to understand what positive feedback means. When positive feedback takes over, and it has done, the reduction is sea ice area will accelerate until no ice is left. That is what positive feedback means!

    I’m confused by your assertion. Firstly, positive feedbacks, such as the ice-albedo feedback, or the water vapour feedback are not specified by the climate modellers directly – they are an emergent property of the underlying physics that is part of the model.

    So, for the ice-albedo feedback, the model has different albedos for open sea and for ice, so that as the ice in the model melts the albedo for open sea is used over a great area, and thus a feedback. The intervention by the modeller is in choosing the values of albedo (for which there are observational constraints) and whether they have implemented some of the “complications” (eg the variation in sea surface albedo due to the angle of the sunlight, or the variation in sea-ice albedo due to meltponds, etc)

    So, the persistance of September sea-ice cannot be because the sea-ice albedo feedback hasn’t been properly understood or implemented, since the feedback is inevitable**. It is an emergent result from the model that needs examining on its own merits.

    I’m not an expert, but from what I’ve seen of the model projections in the past, this residual September sea-ice is piled up on the northern coast of Greenland. Assuming the Greenland ice sheet remains essentially intact for the next few decades, then it doesn’t surprise me that this could create such a local anomaly.

    The presence of Greenland, with all its ice, reduces the impact of the sea-ice albedo feedback in its vicinity and would also be a heat sink for air that flowed over it.

    All the current GCMs treat Greenland as a permanent feature – none of them have an interactive ice sheet model. This is the underlying assumption that leads to a residual quantity of September sea-ice in th eprojections.

    Unfortunately… if the latest news from Greenland is anything to go by, it may well have melted before the modellers manage to model it sufficiently well.

    ** Okay, well. I suppose that if they wanted to a modeller could specify that the albedo of open ocean in the Arctic should be the same as sea-ice. This would be a way of using the model to test what would happen if there wasn’t a feedback (by artificially surpressing it). It might be fun. Also, you would be able to see at which point the no-feedback and feedback models diverged. However, the feedback is probably important in the “normal” seasonal fluctuation in sea-ice extent, so you’d probably mess that up quite a lot.

    Comment by Timothy — 10 Sep 2007 @ 8:28 AM

  441. “SteveSadlov Says:
    7 September 2007 at 22:33
    Someone had mentioned that they thought the East passage would open this year:

    http://www.natice.noaa.gov/pub/West_Arctic/Laptev_Sea/2007/currentcolor.pdf

    Anyone up for a bet?”

    Did you get any takers Steve because right now it looks like it’s opening up? Also after a week or so off stasis the Ice area on Cryosphere today appears to be moving down again.
    Also Hank the Maslowski presentation is very interesting, thanks.

    Comment by Phil. Felton — 10 Sep 2007 @ 8:32 AM

  442. Re #439 where Barton Paul Levenson Says:

    “Alastair, this is almost word for word Chris Dodd’s pseudoscientific argument that the greenhouse effect doesn’t exist.”

    Well, he must be drawing a false conclusion from a well known fact.

    “The back-radiation from the atmosphere has been measured many, many times.”

    And it never balances with that expected. See Some aspects of the energy balance
    closure problem

    Comment by Alastair McDonald — 10 Sep 2007 @ 9:37 AM

  443. Re #440 where Timothy writes:

    ** Okay, well. I suppose that if they wanted to a modeller could specify that the albedo of open ocean in the Arctic should be the same as sea-ice.

    I think if you check, (if you can find a way,) then you will find that is exactly what they have done! (in the Hadley model at least.)

    Comment by Alastair McDonald — 10 Sep 2007 @ 9:45 AM

  444. Alastair, the reference you have provided has nothing to do with radiative balance, but rather convectiveheat flow on long and short timescales.

    Comment by Ray Ladbury — 10 Sep 2007 @ 12:46 PM

  445. Re #440: IIRC the residual ice is postulated because that area is to varying degrees sheltered from wind and current effects. It takes ice a lot longer to melt in place.

    Comment by Steve Bloom — 10 Sep 2007 @ 1:08 PM

  446. Re my previous: Just to add that the behavior of the Canadian archipelago channel ice this year may be cause for some reassessment of how long it’s likely to persist. A melt-out of this sort would have been pretty obvious pre-satellite, and AFAIK there’s no record of anything similar. Also, the current satellite pictures seem to show the northern NW passage has pretty well cleared out as well (although it could still be filled with small bits). Any enlightenment on either of these points, Wayne?

    Comment by Steve Bloom — 10 Sep 2007 @ 1:42 PM

  447. An interesting sentence: “The wildlife agency (the Federal Wildlife Service) had to make a determination on the status of a threatened species because of a suit by environmental groups like Greenpeace and the Natural Resources Defense Council.”

    USF&W hasn’t made it’s determination, it must (not had to) do so in response to the suit.

    The scientific assessment is one step in the USF&W’s process for making a determination.

    Will the USF&W make its determination based on the scientific assessment?

    Back when Bush’s daddy was president, he ordered the head of USF&W to not list the northern spotted owl, despite the scientific assessment that it was indeed in danger of extinction.

    This was the basis of the lawsuit in a Washington (state) Federal District Court that led to a moratorium on the harvest of old growth in western Oregon and Washington. The Endangered Species Act is clear, the agency responsible for determining status (USF&W in these two cases) must base its determination on the known science.

    So things could get quite interesting … at minimum I’m sure the administration will drag out the process as long as possible. It seems quite likely they’ll follow in daddy’s footsteps and rule that polar bears in the US do not face extinction, leading to a new lawsuit to force them to do so.

    If the bear’s listed, oh my, things could get very interesting indeed. In this case, the USF&W will have to prepare a recovery plan, and anything they come up with under the current administration will probably again be the basis for a lawsuit…

    Though the reality is that this process is probably going to grind on into the next administration.

    Comment by dhogaza — 10 Sep 2007 @ 2:26 PM

  448. RE: #441 – If you look at the NOAA link, the red area signifies what is essentially multiyear, “thick” ice – probably at least a couple or three meters thick. The thick black arrows signify the direction of drift. If you were to click on all the sectors covered by NOAA, you’d see that the multiyear ice shown at this link depicting the Laptev Sea is contiguous with the larger mass of multiyear ice up in the actual polar region. My bet stands.

    Slight change of subject …. Cryosphere Today. I used to be a big fan, but lost my fervor when “adjustments” (in both their depicted record as well as ongoing algorithm) were made earlier this year. Here is but one example. The ice edge has never completely moved north of Svalbard this year. The northeastern portion of that island group has remained ice bound. And yet, CT depicts a several Km swathe of open water in a place that is not open to navigation at present.

    Comment by SteveSadlov — 10 Sep 2007 @ 2:59 PM

  449. Ray,

    The Energy Balance Closure Problem is that the radiation at the Earth’s surface does not balance. They write in their introduction:

    During the late 1980s it became obvious that the energy balance at the earth’s surface could not be closed with experimental data. The available energy, i.e. the sum of the net radiation and the ground heat flux, was found in most cases to be larger than the sum of the turbulent fluxes of sensible and latent heat. This was a main topic of a workshop held in 1994 in Grenoble (Foken and Oncley, 1995). In most of the land surface experiments (Bolle et al., 1993; Kanemasu et al., 1992; Tsvang et al., 1991), and also in the carbon dioxide flux networks (Aubinet et al., 2000; Wilson et al., 2002), a closure of the energy balance of approximately 80% was found. The residual is
    Res = Rn − H − E − G (1)
    with Rn: net radiation, H: sensible heat flux, E: latent heat flux, and G: soil heat flux.

    In that paper they try to explain that the problem is with the turbulent heat flux but I am sure it is the net radiation (Rn) that is wrong. Even if I am wrong it is not correct to claim that the downwelling radiation has been measured and balanced for decades. It is what everyone assumes but it is untrue.

    Comment by Alastair McDonald — 10 Sep 2007 @ 3:01 PM

  450. RE: #434 / 435 – Hank, both are correct. The first one has the eastern portion and the second one the western portion.

    Comment by SteveSadlov — 10 Sep 2007 @ 3:03 PM

  451. RE: #426 – Here Bloom, let me help you out. It’s called science. We posit a thesis, then seek to disprove or prove it:

    “Thesis: A combination of AGW, ocean / climate oscillatory effects (e.g. AO, PDO, etc), dark particulate deposits, and Russian river dams, in no particular order. The $64,000 question is, what are the relative contributions?”

    This one’s interesting, because, it has room for everyone from Hansen to the CEO of Exxon. This is the sort of thesis which unifies effort, removes politics, and focusses on the science. Maybe the contribution of AGW is 99%, maybe it’s not.

    Comment by SteveSadlov — 10 Sep 2007 @ 3:09 PM

  452. So far one source of information regarding Greenland melt this flipped summer; Dr. Corell, Heinz Centre, Washington, is cited in the newscoverage of the ecumenic meeting see above posts.
    Whats going on there? Any RC reader with inights on current ‘affairs’ in Greenland – velocites, icequakes, etc. Any open webresources we can follow?

    Comment by horrified observer — 10 Sep 2007 @ 3:27 PM

  453. #443 – Alastair, don’t be silly, that’s absurd. Which Hadley model would you be talking about? (And I’ll see if I can check)

    Comment by Timothy — 10 Sep 2007 @ 4:59 PM

  454. Ok, so the Northeast Passage is at the pair of islands straight across the Pole from Hudson’s Bay; to figure out which photo from which satellite pass will image any Arctic location on a given day,
    go here: http://www.ssec.wisc.edu/datacenter/terra/
    click “Arctic” in the left hand column
    Pick by day and time, then back to the index page for photographs.

    A bit tedious. There’s probably a simpler way to look at a given location over time, that I haven’t found.

    Comment by Hank Roberts — 10 Sep 2007 @ 5:41 PM

  455. As I understand it open to navigation would require that the whole channel be ice free, which open would include regions in which the ice had broken up substantially.

    Comment by Eli Rabett — 10 Sep 2007 @ 5:41 PM

  456. RE: #454 – FYI:

    http://www.natice.noaa.gov/pub/East_Arctic/Barents_Sea/Barents_Sea_North/2007/Northwest/currentcolor.pdf

    Orange is 7 to 8/10ths.

    Comment by SteveSadlov — 10 Sep 2007 @ 7:07 PM

  457. Re:454

    Navigation depends on Ice Concentration, type and thickness of ice, floe size, presence of ice bergs, growlers and bergy bits, Wind directions that can close off a channel or create ice presure, etc.

    The following URL shows a trivial example of what is involved. In reality, things get much more complicated.

    ice navigation

    Comment by Larry — 10 Sep 2007 @ 7:18 PM

  458. Wow. If this goes on, the Russians can put one little icebreaker on station there next summer, and the door’s wide open all the way across.

    I wonder what the toll charge will be for getting through?

    Comment by Hank Roberts — 10 Sep 2007 @ 7:19 PM

  459. Re #s 448/51: Sadlov, if you check the site of your friend “Wrong Way” you’ll find a nice picture showing the NE passage clear for small boats (although as Eli points out not yet for large non-ice-hardened ones). It’s too risky for “Wrong Way” to chance since the ice will close back in with a wind shift, but clear nonetheless. You lose.

    Oh yes: Had you forgotten that there aren’t any dams or major water diversions on those Russian rivers? Also, recall that the “dark particulate matter” is a component of AGW, which also influences the AMO, AO etc. So yeah, it’s mostly AGW.

    Y’know, some people have memories. Regarding CT I seem to recall that you developed your liking for them two years ago when the extent matric (NSIDC) showed a record and CT’s area metric didn’t. Fickle, fickle.

    Once again you neither know nor care about the science or the facts. But at least you’re consistent.

    Comment by Steve Bloom — 10 Sep 2007 @ 7:31 PM

  460. “SteveSadlov Says:
    10 September 2007 at 14:59
    Slight change of subject …. Cryosphere Today. I used to be a big fan, but lost my fervor when “adjustments” (in both their depicted record as well as ongoing algorithm) were made earlier this year. Here is but one example. The ice edge has never completely moved north of Svalbard this year. The northeastern portion of that island group has remained ice bound. And yet, CT depicts a several Km swathe of open water in a place that is not open to navigation at present.”

    As does the NSIDC: http://www.nsidc.org/news/press/2007_seaiceminimum/20070810_index.html

    Comment by Phil. Felton — 10 Sep 2007 @ 8:19 PM

  461. Sorry, the post numbering got messed up, my previous post was in response to: # Eli Rabett Says: 10 September 2007 at 5:41 PM

    Comment by SteveSadlov — 10 Sep 2007 @ 8:31 PM

  462. Responding to Alastair regarding…

    Some aspects of the energy balance closure problem
    T. Foken, et al.
    Atmos. Chem. Phys. Discuss., 6, 3381–3402, 2006
    http://www.atmos-chem-phys-discuss.net/6/3381/2006/acpd-6-3381-2006.pdf

    Alastair McDonald (#449) wrote:

    The Energy Balance Closure Problem is that the radiation at the Earth’s surface does not balance. They write in their introduction:

    “During the late 1980s it became obvious that the energy balance at the earth’s surface could not be closed with experimental data….”

    If the problem is regarding the problem that “the radiation at the Earth’s surface does not balance,” why is it it called the “energy balance closure problem”?

    I also notice that the equation that you quote refers to sensible heat flux, latent heat flux and soil heat flux. So it would seem that the problem wasn’t strictly related to radiation but energy.

    Alastair McDonald (#449) continues quoting the paper:

    “In most of the land surface experiments (Bolle et al., 1993; Kanemasu et al., 1992; Tsvang et al., 1991), and also in the carbon dioxide flux networks (Aubinet et al., 2000; Wilson et al., 2002), a closure of the energy balance of approximately 80% was found.”

    Eighty percent? Seems pretty serious.

    Alastair McDonald (#449) wrote:

    In that paper they try to explain that the problem is with the turbulent heat flux but I am sure it is the net radiation (Rn) that is wrong.

    Turbulent heat flux? I thought this had to do with radiation.

    Lets look at what they have to say on the next page, Alastair.

    The most common point of discussion were measurement errors, especially those of the eddy-covariance technique, which cause a systematic underestimation of the 5 turbulent fluxes. Improvements in the sensors, in the correction methods and the application of a more stringent determination of the data quality (Foken et al., 2004) have made this method much more reliable in the past ten years (Moncrieff, 2004).

    pg. 3383

    Hmmm.

    Things have improved. Sounds good.

    But how well have they improved?

    For an exact determination of the soil heat flux, including storage effects, the energy balance was shown to be closed at night for non-turbulent conditions (Mauder et al., 2006). The storage in the canopy is often negligible.

    pg. 3383

    Closure in the absence of turbulence. Looks like things have improved a great deal then. And it doesn’t look like a problem having to do with radiation afterall – since things balance in the absence of turbulence.

    Alastair McDonald (#449) wrote:

    Even if I am wrong it is not correct to claim that the downwelling radiation has been measured and balanced for decades. It is what everyone assumes but it is untrue.

    Downwelling radiation is measured – and I have given you sources for the spectra before.

    Balanced?

    Downwelling radiation isn’t balanced in isolation. Downwelling radiation is balanced against something else. Upwelling radiation perhaps – if it is at the top of the atmosphere. Or upwelling radiation and other heat fluxes (e.g., turbulence) if at the surface.

    Anyway, thank you for pointing out the article: it shows that climatologists aren’t simply engaged in armchair theorizing or making stuff up as they go along.

    Comment by Timothy Chase — 10 Sep 2007 @ 8:31 PM

  463. #447 dhogaza

    “USF&W hasn’t made it’s determination, it must (not had to) do so in response to the suit.” True, the final decision has not been made on the status of the polar bear. The final decision is due this January which gives plenty of time to delay until 2009.
    William has an interesting critique of the assessment on stoat:
    http://scienceblogs.com/stoat/2007/09/charismatic_megafauna.php#more

    Another Endangered Species Act suit has progressed further. The NMFS has started to create a recovery plan for elkhorn and staghorn corals. NMFS had admitted the corals are threatened in part because of higher ocean temperatures. NMFS also admits that that this is due in part to AGW, but accurately states that there is no current regulatory framework to address AGW.
    http://www.enn.com/press_releases/2130

    Comment by Joseph O'Sullivan — 10 Sep 2007 @ 9:10 PM

  464. #446-455, The only thing stopping a competent Cargo ship Captain from using the Northwest Passage is purely psychological. The gates of this passage was ice as tall as masts and many who dare pass it with ships froze to death or got so spooked, after surviving a near death experience told stories which still scare the willies out of any mariner to this day. As NSDIC chap said its been open, the only barrier is charting a deep channel course without remembering the dead frozen. Present day scattered ice floes here and there are so rare, didn’t dissuade our resupply ship (relatively small Cargo ship with two cranes) from arriving this last weekend (gone today).

    Resolute Bay should have been called Winter Harbour (Melville Island) after a 1947 Armada of ships from Boston was forced to stop next to Cornwallis, ice breakers could not go further West due to a huge barrier of multi year ice spanning Barrow Strait entirely, this yearly fall barrier is history along with the frozen sailors, in its wake , just water lots of sea water.

    Comment by Wayne Davidson — 10 Sep 2007 @ 9:19 PM

  465. Another interesting graphic on today’s NSIDC update, their graph of area shows a further drop of 180,000 sq km last week slowing though. The really interesting one is fig 3 which shows perennial sea ice, i.e. the area which has been frozen everyday since the satellite monitoring started in 1979, it shows that a substantial portion of that has gone this summer (~400,000 sq km).

    Comment by Phil. Felton — 10 Sep 2007 @ 10:29 PM

  466. Wayne Davidson – man on the spot! Could you give us a google place marker for you so we know where you are looking from?

    Comment by Nigel Williams — 11 Sep 2007 @ 12:52 AM

  467. Has anyone noticed that North Pole Netcam XL #4 is the only camera still in operation? It had some crazy pictures today-

    5am:
    http://www.arctic.noaa.gov/npole/2007/images/noaa4-2007-0910-051654.jpg

    2pm:
    http://www.arctic.noaa.gov/npole/2007/images/noaa4-2007-0910-141744.jpg

    does anyone know the long/lat coords of these cameras?

    Comment by Anthony Shafer — 11 Sep 2007 @ 12:55 AM

  468. Nigel

    Try this: http://www.gov.nu.ca/resolutemap.htm

    Comment by Wayne Davidson — 11 Sep 2007 @ 1:07 AM

  469. #443 Alastair, I can’t find out what albedo any of the Hadley models use for open ocean, but I did find some documentaion of their latest model, which includes the following (as well as a detailed discussion of their sea ice albedo calculations):

    [sea ice] “is also important in climate change because of the ice-albedo feedback: decreasing ice cover results in more absorption of solar radiation at the surface because open water has a much lower albedo than ice.”

    That looks like an understanding of the feedback to me.

    #445 – Thanks. Yes,Greenland is likely to effect the circulation which could be (locally) more important than energy balance changes.

    Comment by Timothy — 11 Sep 2007 @ 5:41 AM

  470. Alastair writes:

    [[Even if I am wrong it is not correct to claim that the downwelling radiation has been measured and balanced for decades. It is what everyone assumes but it is untrue.]]

    You’re moving the goalposts. Your contention was that there was no significant back-radiation. In fact there’s about 300 watts per square meter of thermal radiation from the atmosphere. The imbalance in the surface budget is far less than that. The greenhouse effect works just like the books say it does.

    Comment by Barton Paul Levenson — 11 Sep 2007 @ 5:55 AM

  471. I looked at the Cryosphere Today pics of the Arctic sea ice that have been complained about. “Several kilometers” would be about a pixel and could be merely an artifact of rendering photographs on a monitor. If there are other pics that show more detail, please provide a link.

    Comment by Jeffrey Davis — 11 Sep 2007 @ 8:06 AM

  472. Re #470

    OK, I’ll move the goal posts back again then. (I am acting on a tipoff from Timothy :-)

    The radiation emitted by CO2 and to some extent H2O does not depend on temperature, only on the excitation state of those gases. This is a well known fact amongst spectroscopists, physical chemists, and quantum physicists but not by climatologists.

    Since the the bands are saturated, increasing the concentration of CO2 will not increase the back-radiation. However, it will increase the energy absorbed in the lowest layer of the atmosphere and result in it warming. Unfortunately this insignificant layer, only about 30 m high, is where we and much of the rest of the animal and vegetable kingdoms live.

    Comment by Alastair McDonald — 11 Sep 2007 @ 9:30 AM

  473. #467: It says here that netcam 4 is on the Polarstern:
    http://www.arctic.noaa.gov/gallery_np.html
    There’s a map here showing the position of the Polarstern:
    http://www.awi.de/de/infrastruktur/schiffe/polarstern/wo_ist_polarstern/
    which my eyeball suggests is about 87N, 180E.

    Comment by Nick Barnes — 11 Sep 2007 @ 9:46 AM

  474. #466/468: Resolute is at 74.7 N, 94.85 W.
    http://maps.google.com/maps?q=74.69N,94.85W&z=12&t=h

    Comment by Nick Barnes — 11 Sep 2007 @ 9:50 AM

  475. RE: #459 – That “passage” is a dead end. It does not go all the way through.

    Comment by SteveSadlov — 11 Sep 2007 @ 11:16 AM

  476. RE: #464 – If I understand you correctly, you are in Resolute Bay. What can you tell us about the state of the NWP between your location and the Beaufort Sea? Tell us about its state now, and during the past couple of months. Thanks.

    Comment by SteveSadlov — 11 Sep 2007 @ 11:22 AM

  477. RE: #467 – In the interest of facts, the current location of the so called NP web cams is substantially south of the pole. Every year, cams are placed at ~ the NP in April. Then, they drift with the ice. Typically, they will drift quite far to the south, sometimes into the low 80s latitude.

    Comment by SteveSadlov — 11 Sep 2007 @ 11:25 AM

  478. Anthony, “North Pole” cameras 3 and 4 aren’t at the North Pole:

    “Web Cams #3 and #4 are on the R/V Polarstern (from Alfred-Wegener-Institut) which is working its way north from Norway to solid ice, where these web cams will be deployed. Updates will be posted on this website as they become available.”

    Cameras 1 and 2 were last heard from in early August, when their mounts had tilted and, from the pictures, appeared to be melting.
    http://www.arctic.noaa.gov/gallery_np.html

    Looks like they found solid ice, since those pictures show people in orange suits standing on it; their website doesn’t yet say the location though. http://www.awi.de/en/infrastructure/ships/polarstern/

    Comment by Hank Roberts — 11 Sep 2007 @ 12:15 PM

  479. Re #475: on the question of ice in Vilkitsky Strait, I think the words of Wrong Way Flanagan – on site and preparing to sail single-handed through it – should carry rather more weight than those of some random commenter on RC.
    http://agx.firetrench.com/?p=219
    “The Western end of the route is reported to be ice free”.
    The strait is clearly more open now than it was a few days ago – compare that Radarsat image with the one here:
    http://agx.firetrench.com/?p=216
    It is very likely more open than it was in this chart from two/three weeks ago:
    http://www.natice.noaa.gov/pub/West_Arctic/Laptev_Sea/2007/currentcolor.pdf
    Anyone know where we can get Radarsat images like these?
    Best of luck to Flanagan.

    I find it curious that people put so much emotion and energy into debating these fine details. The big picture is clear: there has been massive loss of Arctic sea ice, especially thick multi-year ice, over the last couple of decades. A number of proximate causes for this have been identified – polar anticyclones, the AO, etc. The existence of feedback mechanisms accelerating this loss – including but not limited to the simple albedo effect – is well-known. The domain experts believe that we are at, or past, a “tipping point”, and that we’re heading rapidly to ice-free arctic summers. If the two passages are not both open now, they will be so in 2008, or 2009, or 2010.
    So: the arctic is changing. What are we going to do about it?

    Comment by Nick Barnes — 11 Sep 2007 @ 12:46 PM

  480. Re #475: Interesting. The accompanying text said it was open all the way (although not safe to use due to the prospect of shifting wind). Also, as noted above, the new NSIDC post finds that the ice lost another 180k km^2 in the last week; slowing certainly, but no minimum yet. But any day now, you’ll be right.

    Comment by Steve Bloom — 11 Sep 2007 @ 1:29 PM

  481. In fact, the later Radarsat image at the Alpha Global Expedition blog shows that the strait is far more clear than in that NatIce chart. The Radarsat shows clear water in an inshore channel around the northeastern coast of the Taymyr peninsula (marked up as the blue path on the AGX page). The NatIce chart (from 27-31 Aug) shows this coast as completely blocked (the southern end of section P).
    I should have realised this earlier, but I wasn’t lining up the charts correctly.

    Comment by Nick Barnes — 11 Sep 2007 @ 1:40 PM

  482. #477, Steve Around Resolute, yep, wide open, I can’t answer for the Beaufort, but they can:

    http://www.natice.noaa.gov/pub/West_Arctic/Canadian_Arctic_West/2007/currentcolor.pdf

    Usually done with radarsat shots. Latest product is a bit late, newer one should be on any time soon. Not long ago, it was wide open Ice Free (IF),. A lot of people here have been using ordinary satellite pictures in order to figuire out open water etc. Some of theses pictures have a mix of clouds, fog and ice, poor contrast resolutions (some ice not seen in certain settings) making it difficult to do a correct assessment, the Radar Satellite shots are Sea faring industry standard.
    Ice also migrates as the wind blows, so a “blockage” one day is gone the next. For a non icebreaker ship Captain huge red zones are a dead end.

    Comment by Wayne Davidson — 11 Sep 2007 @ 2:02 PM

  483. http://en.wikipedia.org/wiki/Northern_Sea_Route

    With that, I will concur with (Nick Barnes Says:11 September 2007 at 12:46 PM) regarding the need for a big picture view. For 2007, what has been the most obvious oddity has been the degree of melt back in two specific basins – the East Siberian Sea, and the Chukchi Sea. While Svalbard has incurred a poor melt back, these two basins have been completely cleared. I noticed that Polarstern has given up on reaching the pole and instead, seems to be doing some sort of study in the area of the NW Chukchi and NE East Siberian. Good for them. That is definitely where I would want to be, to look at the issue.

    Comment by SteveSadlov — 11 Sep 2007 @ 3:15 PM

  484. There’s a status update on the NSIDC site (http://nsidc.org/news/press/2007_seaiceminimum/20070810_index.html).
    New alltime low sea ice extent (4.24 million km2), and large areas that have no ice for the first time.

    Comment by Ark — 11 Sep 2007 @ 3:50 PM

  485. Here’s the MODIS/Terra satellite image from a few hours ago of the NorthWest Passage.

    http://rapidfire.sci.gsfc.nasa.gov/realtime/single.php?2007254/crefl1_143.A2007254191500-2007254192000.4km.jpg

    The middle passage is closed off by the sea ice in the Beaufort Sea while I think a ship could slip through in the Southern passage if they were steaming full speed ahead (and were willing to take significant risks.)

    Last week, the inner passages of all routes were closed off by ice but it has melted this week.

    Comment by John Wegner — 11 Sep 2007 @ 9:44 PM

  486. Nick #479,

    I totally agree: whether or not the North West Passage (or indeed the North East) is open is a complete irrelevancy to me. As far as I can see we’re heading for a seasonally ice free Arctic, an end state that we will reach faster than previously thought.

    What will be the impact on the trajectory of Northern Hemisphere warming (hence global warming)?

    What will be the impact on Northern Hemisphere(NH) precipitation patterns?

    What will be the impact on Greenland’s northern flanks and Arctic river discharge, hence sea level rise (this rapid loss of Arctic ice seems to Bolster Hansens cries of alarm)?

    What will be the impact on resource availability and costs (particularly fossil fuels)?

    What will be the impact on Northern Hemisphere trade/economy/politics?

    It really looks like we’re in a rapid (decadal+) transition to a seasonally ice-free Arctic. This is an event that draws an impenetrable veil over the future.

    Comment by CobblyWorlds — 12 Sep 2007 @ 12:43 AM

  487. John Wegner, why have you made over a dozen repetitive posts to cast doubt on NSIDC data and to fight back the mainstream news item that the NW passage is open? Are you being paid to play that role?

    Comment by George — 12 Sep 2007 @ 3:31 AM

  488. CobblyWorlds #486. Yes, these are the key questions now. Also, what will be the impacts on the arctic ecosystems? As far as I know, we have no evidence of ice-free (or largely ice-free) arctic ocean summers, going back into prehistory. The organisms and systems of the arctic are highly adapted to the sea ice, from the aquatic micro-organisms mentioned in earlier comments all the way up to polar bears and whales. This sudden disappearance of the ice is undoubtedly catastrophic.
    As an amateur, I expect the most significant long-term climate impact to be accelerated melt of Greenland and of the smaller ice sheets, due to albedo-driven regional warming. There are positive feedback effects specific to melting of glaciers and ice sheets (for instance, the lubrication of ice movement by melt water under the ice). Just as for the sea ice, we don’t really know the magnitude of these effects and the domain experts seem to be becoming gravely concerned that they have been underestimated.
    But as I say, I’m only an amateur. Any Greenland experts nearby? Are there any useful sources of relevant data on the web, like CT and the NSIDC sea ice page?

    Comment by Nick Barnes — 12 Sep 2007 @ 5:40 AM

  489. RE # 486

    Cobbly: allow me to edit your comment:

    This is an event that draws an impenetrable veil over the future [of ethanol in Western North America}. This might be a good time to consider dumping ethanol shares, if you own them.

    Comment by John L. McCormick — 12 Sep 2007 @ 8:34 AM

  490. John Wegner wrote earlier that he believes the optical satellite images are more accurate than the radar imagery. Cite please? If you are the John Wegner who has published research on the Arctic, from Emory, you may be speaking from personal experience; that’d help. Of course we can’t tell who’s behind a name, as ordinary readers.)

    Wayne Davidson in this thread just above (11 September 2007 at 2:02 PM) says the shipping industry relies on the radar satellite images.

    Comment by Hank Roberts — 12 Sep 2007 @ 10:19 AM

  491. CobblyWorld #486 and Nick #479,

    I also find it interesting that so much is written and debated while the big picture remains veiled. The veil may remain however because we choose to not pull it aside and see what we’ll have to do to avoid a rather short nasty future. Today, we are admitting most of the polar bears, walruses, and seals dependent on ice floes for birthing will not survive the warming already built into the system. Today we are beginning to admit quite a bit of the ice of Greenland will melt in this century (probably sooner) and much of the planet’s coasts will be flooded by the resultant rise in sea level. Millions will be displaced. However, we, as an organized planetary civilization, are very reluctant to make the next step and move away from the easy fixes of Al Gore and towards the stark reality mandated in George Monbiot’s “Heat” and Mark Lynas’ “Six Degrees”.

    Today, the average American produces about 25 tons of fossilized carbon dioxide or its equivalent in other greenhouse gases a year, the average European about half that. (IPCC 4th Assessment Report, WGIII, Summary for Policymakers) Yet Monbiot makes the clear argument that to lower CO2 additions to the atmosphere to manageable levels while being fair to everyone on the planet we will have to reduce the European amount by about 90%, the American level by 95%. And we have to make the change to this lower level in the next few years or, basically, it will be too late.

    As we see now in the Arctic, the positive warming feedbacks from the natural systems involved will overwhelm our ability to check that warming. The planet will go from the positive feedback of an albedo change through the positive feedbacks of methane release from the melting permafrost and carbon release from burning forests to the terminal stage of massive positive feedback from methane releases from melting methyl hydrates on the ocean floor. And it may do this in a geologic blink. Can anyone say the warming will stop before we reach Venus-like temperatures on Earth’s surface? Water vapor is also a greenhouse gas so we cannot depend on the oceans to stop the warming; they will also become a major positive feedback at a certain point.

    IMO, the planetary civilization has only two realistic choices that do not involve weapons of mass destruction, replace or restrict fossil fuels very soon or face runaway global warming. I’d like someone in this group to add more choices to my rather limited list. I hope this rather simple man has missed a lot.

    Comment by Mike T — 12 Sep 2007 @ 10:29 AM

  492. RE: #487 – NSIDC’s approach relies on lots of post processing of passive microwave data. It is highly appropriate to look deeply into it. It’s all about counting pixels, removing “suspect” ice from the data, and, the ever difficult challenges of discerning between clouds, bare ice, and the snow that covers portions of the ice. It is a non trivial thing to get both the areal extent plots and to derive the graphical images shown at NSIDC, Cryosphere Today, etc. This is not to say that, in the big picture, extent has not declined since at least the late 70s. What it is to say is, in order to be maximally scientific, accuracy is important. It lends credibility to threat assessments. It eliminates hype.

    Comment by SteveSadlov — 12 Sep 2007 @ 10:57 AM

  493. Don’t worry about oil from the artic for now. It will take many, many years to get any from there. That fruit is very unripe.

    I do bother about weather patterns this winter, next summer melting, and what happends from there on.

    Comment by Alex — 12 Sep 2007 @ 11:19 AM

  494. Hello,

    I’ve been following the situation in the arctic for awhile now, and very closely this year. I also discovered RC earlier this year and have been absorbing all the content. This is my first post on RC. Some of my thoughts (forgive me if I ramble):

    It seems that this story (about the severity of the sea ice loss) is getting buried by the media. And when it is referenced, they still try to paint a picture of ice-free summers as far off as 2030 -2050. Now, for those following the situation, I think almost all of us would agree that we will see an end within a couple years. The most likely range is probably 2009-2012. Even if somehow it defied all odds and lasted until 2015, that is still a long ways from 2050. So why is it that this study came out on the 7th of September, amidst the most catastrophic loss of sea ice on record?

    http://www.cnn.com/2007/TECH/science/09/07/low.ice.ap/index.html

    Articles like this seem to be designed to intentionally mislead the public. I’d call it sloppy journalism if it didn’t seem so purposely constructed. And then there was another article today (also CNN) which depicted the scene a little more realistically. It featured numbers and comments from NSDIC senior research scientist Mark Serreze. I figured the truth would finally be told… but instead he pulled the rug out from under our feet and laid this egg : ‘Most researchers had anticipated that the complete disappearance of the Arctic ice pack during summer months would happen after the year 2070, he said, but now, “losing summer sea ice cover by 2030 is not unreasonable.”’
    http://www.cnn.com/2007/TECH/science/09/11/arctic.ice.cover/index.html
    Back about a month ago, as sea ice dipped below the old 5.32 record, I predicted that if conditions persisted, sea ice could hit 4.25. Now that we are slightly below that figure, (and still slowly plodding along) I don’t feel good about being right. Denialists can continue to call us alarmists if they wish. At some point, people are going to wish they had heeded those bells sooner.

    Comment by Ryan McCourt — 12 Sep 2007 @ 12:05 PM

  495. Hi! I have been following the sea ice melt. I am a botanist, so weather and climate patterns are very important to me, but I am not an expert on climate. If the jet stream shifts north, it will either cause massive drought here in southern California, or floods as the subtropical jetstream comes north. Perhaps both, varying from year to year.

    Anyway, I have a question that maybe someone here can help me with. I don’t understand why melting Arctic ice would make the jet stream shift north. Once the ice melts, the coldest areas would be over Canada and Siberia in the winter, not the Arctic, right? Wouldn’t this actually shift the jet stream south as high pressure associated with the arctic circulation would set up over the continents rather than the Arctic? Also, wouldnt air actually flow from Canada and Siberia TO the arctic?

    Wouldn’t this cause big dips of the jet stream over Asia and North America? This wouldnt necessarily bring more rain to California though, as the winds would be coming off of the mainland. This might actually result in colder, drier conditions in California.

    Ideas?

    Comment by Charlie — 12 Sep 2007 @ 12:23 PM

  496. CT update: 2.92 million square kilometres.
    Also the southern hemisphere ice area is at a record high: 16.26 million square km.
    Re #491: Consider both these facts together, and add the fact that the dramatic arctic sea ice loss is a complex phenomenon not entirely attributable to AGW. If the world were heating up that quickly, the antarctic would be melting too.
    Please, stop speculating about methane hydrates. There’s more than enough noise on this channel already. It takes centuries for heat signals to propagate down to the sea floor: the clearer consequences of AGW are far more urgent, and give us plenty to worry about and work on in the meantime.

    Comment by Nick Barnes — 12 Sep 2007 @ 1:17 PM

  497. #494: The thinner ice in the central arctic basin, the laptev sea, the northern beaufort sea, north of Svalbard, etc, might go in the next few years, as the melt seasons start earlier, run faster, and end later because of the warmer sea temperatures (although this year has seen remarkable weather conditions which might not be often repeated; 2008/2009 might well have more ice than this year). And much of that ice might also be swept (by the gyres and the trans-polar drift) into the multi-year pack, not to be replaced. But the thick multi-year ice, packed up against Greenland and the Canadian Archipelago, might survive long after 2015. It’s a very cold part of the world, and likely to remain that way for a while because of the cold landmass. As I understand it, that’s why Serreze and colleagues are looking at 2030 or beyond.

    Comment by Nick Barnes — 12 Sep 2007 @ 1:27 PM

  498. Well the new cryosphere results are in for Sept 12, and we are at a new all time low for ice area. Ironically the south pole is at an all time maximum for ice area.

    Im sure the denialists will jump all over the SH numbers, however statistically the SH numbers mean very little, and is just the typical variance, you would see in a small sample.

    On the other hand, the NH numbers are extremely significant statistically.

    Comment by Larry — 12 Sep 2007 @ 2:29 PM

  499. Don’t worry about oil from the artic for now. It will take many, many years to get any from there. That fruit is very unripe.

    movie scenario. very unripe.

    15 years from now, you’re a crew member on one of the mobile rigs pumping oil in the summer and early fall from the arctic basin. You’ve got a good job. Seasonal work, but the monthly is so high you don’t have to work the rest of the year. You’ve had a hard day. It’s Miller Time! You and your bearded buddies kick back, open some brews, light some cigars, and (after some Bruce Willis wise cracks and male bonding jokes), the lit stogies light fumes and blows everyone to hellandgone. The gusher burns furiously and incandescently (think “Wages of Fear”) for months until aged, creakiest Bruce Willis(!) arrives to put out the fire. Triumph! The crew kicks back, drinks beer, smokes stogies. Meanwhile, all the ice on Greenland melts and the resulting tsunami swamps the vessel assigned to put out the well head fire.

    Yippie-ki-yay.

    Comment by Jeffrey Davis — 12 Sep 2007 @ 2:49 PM

  500. Hello everyone – I too have been watching the sea ice and am confused about the new historic maximum in the antarctic ahile we have a new historic minimum in the arctic. Can someone explain why global warming would cause this? Is it that the variations are going to be increasing?

    Comment by Sue — 12 Sep 2007 @ 3:18 PM

  501. I hereby apologise for referring to the Vertical Circumnavigation’s sailor as “Wrong Way Flanagan.” Sadly, I was roped in by some very inaccurate news reporting. In fact, this project is highly competent, and Flanagan is doing it the way I would do it:

    http://agx.firetrench.com/?p=220

    By the way, this has been a very good experience in terms of learning and advancement of the sailing arts. I believe that Vertical Circumnavigation will in fact succeed someday, no matter what the sea ice trend is. Timing is the key. And luck.

    Comment by SteveSadlov — 12 Sep 2007 @ 4:09 PM

  502. RE: #495 – There is good reason to believe that the existence of large fetches of open water in the Arctic during the Fall, can indeed lead to increased storminess. Also, not to engage in hype or doom and gloom myself, but, although Whitley Strieber and Art Bell’s book “Global Superstorm” is rife with non physical / scientifically impossible aspects, at the 50K foot level, it is not unthinkable that low sea ice extent, noise / excursions in the THC and other factors could in fact induce the end of the current interglacial. Earth history is on the side of being conservative and keeping the possibility of relatively rapid (e.g. millenneal scale) major climate change on the table as a possibility. “Day After Tomorrow” is hype, but, a hundreds of years long version of such events is possible.

    Comment by SteveSadlov — 12 Sep 2007 @ 4:17 PM

  503. Hey!!

    I am a Research and Development technician, but study climate change as a side interest. I have a BAD feeling when it comes to societal viability over the next 30 years or so. It’s just my opinion…and I am not a climatologist, but I think we’re screwed (my best scientific description). It’s not that we meant to end most of the mammalian life on the planet…we just didn’t know the extent we were damaging the earth (debatable I know). I believe that there has been an absolutely CRITICAL balance of CO2, Oxygen, Nitrogen, Nitrous Oxide, Methane, etc, present on the earth for Eons. We have disrupted that balance. It’s not biblical…nor magical, just simply physics that we failed to understand in time (not that we really understand it now..but we’re beginning to). It’s my opinion that this critical gas balance has been and is the earths perfect thermostat. We have turned up that thermostat…but unfortunately AFTER we build our society, cities, and established our way of life. The melting of glaciers, ice-sheets, etc is ONLY THE BEGINNING. And I do mean the beginning. It is going to get FAR worse. WE have seen NOTHING yet. Wait 30 years…we will see in our lifetimes…situations we thought we impossible…weather that will SCARE you. It is going to be an interesting future. The worst part about this…is that I think the government knows…and I don’t just mean they know about global warming…that is real..I mean they KNOW how bad it really is…and how bad it is going to get. Which is why there is so much disinformation about global warming out there…so many deniers…$10,000 payoffs to scientists willing to trash global warming science. I am not the smartest man on the planet…but am I the only one who feels that this is the case????? Get back to me!!

    Parm

    Comment by Parm Gander — 12 Sep 2007 @ 5:07 PM

  504. Ryan @ 494,

    This, also, is my first post here, and I can’t claim any credentials beyond a few stray neurons sporadically firing after decades of abuse.

    Your first complaint is burial by “the media”, and an attempt to mislead by reporting old information.

    The US Congress is holding hearings that have been hyped for many months on an issue that is preeminent to consumers of “media” output. That is major noise.

    Selling both Chevy Suburbans and solar panel kits is easier with Polar Bears than IR satellite output. There is a legal issue driving the research underling the CNN story in your first link — a petition to up-list Polar Bears under the Endangered Species Act is pending. CNN and its ilk are responding to the conclusions published by
    Overland and Wang in Geophysical Research Letters. The authors publish when they publish, and they use the data they have.

    The second link seems to refute your point. Four days later the extent of this year’s ice is the subject.

    Your second ‘plaint, that Serreze “pulled the rug out from under our feet” is based on what? That he failed to support your prediction – apparently made elsewhere, if made a month ago and this is your first contribution – of the outside date for the Arctic Ocean being seasonally ice free is 2015?

    I’m probably every bit as alarmed as you. I’m just cautioning you to remember and respect the “real” part of this forum’s title, and not amplify the noise at the expense of the signal.

    Comment by Stuart Jensen — 12 Sep 2007 @ 6:56 PM

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