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North Pole notes (continued)

Filed under: — gavin @ 22 August 2008

This is a continuation of the previous (and now unwieldy) post on the current Arctic situation. We’ll have a proper round up in a few weeks.


638 Responses to “North Pole notes (continued)”

  1. 551
    Pekka Kostamo says:

    Still trying to dig and digest this sea ice issue …

    Apparently the Arctic Ocean is a quite unique place with many unusual features. It has a rather closed cirulation. Moreover it has a three-layered structure maintained by differences of water temperature and salinity.

    The uppermost layer is low salinity water supplied by precipitation and the great rivers of Siberia and Canada plus the melting of winter ice (the ice is fresh enough to supply drinking water to the explorers). Under ice there is little mixing due to wind. This is most of the year and nearly all the area as the ocean is frozen from coast to coast. The surface layer depth would start to vary with the seasons when the ice melts.

    A middle layer (down to about 400 meters) results from the inflow of Pacific surface water via the Bering Strait. The Strait is surprisingly narrow (60 km) and shallow (50 meters) with a typical northward flow of 1 m/s. This is Pacific mixed (surface) layer water that has been pre-conditioned in the Bering Sea (conditioning subject to seasonality). The middle layer has higher salinity and lower temperature than the surface layer.

    The bottom layer is deep circulation Atlantic water, highest in salinity but warmer than the Pacific one.

    An interesting issue is of course how stable this arrangement might be? The surface layer is thin, numbers like 22 – 50 meters have been mentioned. Reduced mixing there might explain the observed thinning of ice.

    How much of the summer excess energy is stored by the water over the winter? Ice and snow are insulators and mixing is low, so not necessarily all of the extra energy is lost during the wintry nightlike conditions.

    Another probably quite critical aspect is that according to the above mechanisms, the Arctic Ocean harvests solar energy from over a far wider geographic area than its own extent. The warm plumes were quite clearly visible as growing open water patches in the 2007 imagery. These external sources heat the two uppermost layers. The summer of 2007 was hot in Siberia, and there was a major warm anomaly in the Bering Sea as well (and much less so this year). This is of course additional to the “local” surface processes discussed i.e. in this thread.

    This is just some qualitative thinking aloud. Monitoring in the area is minimal apart from the surface parameters. One usefull effort might be to seek further access to the extensive U.S. and Russian navies records from the area.

  2. 552
  3. 553
    Chris says:

    #533 Cobblyworlds

    Thanks for your reply to my earlier post. I’ve just downloaded Bhatt et al to read when I get a spare moment, and will go look at Stoat’s page too. I respect that you think it’s a “done deal” in the Arctic if you mean it’s hard to make a strong case for Arctic ice recovering to say 1980s levels. But I would maintain that a significant recovery, along with a failure to melt in summer by 2030 (by which time incidentally the AMO may have retreated to cool phase) should not be ruled out, just like the shorter term recovery we’ve seen recently should not have been ruled out in late Aug/early Sep when some were predicting minimum ice extent down to 4 million with minimum as late as Oct.

    #532 Wayne: “Barton, Chris is usually long with explanations that don’t add up to much. His recap of the summer ice melt is long as well, misses most of the main features which have happen.”
    lol – and Wayne’s explanations always add up?

  4. 554
    Sekerob says:

    For the bridge-nose viewers, compared to 2007, there is 1.54 million km2 more SIE yesterday. Opposed there is per these “Chris” sources about 400 thousand km2 more SIA (CT data for 15th not available yet).
    My Own Composite http://i137.photobucket.com/albums/q210/Sekerob/ArcticSIE-SIA2007-2008MeltProfile2.png
    with some numbers for statisticians. The 2007 SIA is a function of the JAXA SIE as I could not find the daily data. Will though work out at 4.5m km2 for the months average. The purpose was though the highlight of the increased “spread” of ice” i.e. how broken up it is. For instance the to get from SIA to SIE in 2007 there has to be 27.8% of water areas added. For 2008 the situation for 15 days running October is 36.2%, again CT day data for the 15th not available at time of writing.

    For the 15 days average I come to 818 thousand km2 more SIE and 335 thousand more SIA, a 75:25 ratio.

    The state of the cryosphere is poor and at the 2008 low there was less volume (km3) than 2007. Given that historically for some year on year, 37% change in Arctic ice has been reported, it is a rather brain dead exercise to conclude anything, but extreme reservation. Regardless of e.g. La Nina and a poorly Arctic summer, things are still rather crispy. All and particular NH temps continue to have underlying trends when removing all the short term noise. That’s my reading of the various global temp tracker sources.

    Watch for JAXA October 15 odd anomaly as with the June 1-2. This is where JAXA flops the algorithms to account for the melt ponds. To me, SIE is a way to measure, but the SIA-SIE diversion is much more indicative of the inferred quality of Sea ice floating around. If Not, Tell Us?

    PS, ignore the poly line for 2008 Extent projection suggesting that the 2008 SIE will break through all 2002-2007 levels in October. Still looking for a daily simple data set in ASCII providing the SIE mean for 79-00 that is shown for instance here: http://nsidc.org/data/seaice_index/images/daily_images/N_timeseries_thumb.png. Anyone knows where it is obtainable? No replies to email requests.

    Use lots of words too, inglese is not my native tongue ;>)

  5. 555
    Cobblyworlds says:

    Hello Chris,
    I was never persuaded by the claims there’d be a late melt this year (too little ocean warming). I hope you are correct, I fear not. If I am right we cannot avoid what is coming, if I’m wrong I could provide an excuse for inaction. So I’m stopping posting, and haven’t the heart to carry on studying.

    Pekka Kostamo,
    Thanks for another interesting comment.

    Humble thanks to RC for correcting my former ill-advised scepticism.

    Bye all.

  6. 556
    Hank Roberts says:

    http://www.sciencedaily.com/releases/2008/10/081006180815.htm

    “Rising Arctic Storm Activity Sways Sea Ice, Climate

    ScienceDaily (Oct. 14, 2008) — A new NASA study shows that the rising frequency and intensity of arctic storms over the last half century, attributed to progressively warmer waters, directly provoked acceleration of the rate of arctic sea ice drift ….”

    Watch the distinction between area and extent; I think the ratio between them, to the extent we know the numbers, could be worth reporting as broken ice spreads out into open water.

  7. 557
    Arch Stanton says:

    Cobbly, I hope you feel better soon. When you do perhaps you will examine your motivation for stopping at the next phase of skepticism. Moving from: “It’s not happening” to “it is happening and there is nothing we can do about it”, isn’t the place to stop studying.

    The fat lady hasn’t sung yet.

    Thanks for your contributions, Take care.

  8. 558
    Hank Roberts says:

    Sekerob asked where to find the data:

    http://nsidc.org/data/seaice_index/archives/index.html

  9. 559
    Sekerob says:

    Thanks Hank, got that whole set except, it’s monthly data though, lest I missed something. Looking for daily tabulations. Fabricated e.g. the next 2 chart with that for Ant&Arctic and global. http://i137.photobucket.com/albums/q210/Sekerob/ArcticSIASIE2-1.png & http://s137.photobucket.com/albums/q210/Sekerob/?action=view&current=AntarcticSIASIE2.png

    Later found this chart format to exist in similar fashion somewhere else.

    recaptcha: now applying

  10. 560
    Chris says:

    #555 and #557. Slightly OT:

    IMO, depression about a construct is not rational. Climate change worst case scenarios have this emotive psychological effect akin to imagining a future roller coaster ride where everybody screams as it lurches into each new and scarier twist. But life is lived by individuals, who have no choice as to when and where in the world they are born, and take life as they find it. I would not be angry if I was born 50 miles up the road from my parents’ home town because they had re-settled due to rising sea levels (construct = “mass migration due to catastrophic rises in sea level”), or if I was born into an area where the local flora/fauna had changed in the decades before (“irretrievable damage to local ecosystems”), or if I grew up in the midst of a re-organisation of regional agricultural production and trading (“extreme drought endangering millions”), any more than I am angry to have been born in present-day England, where the weather is gloomier than almost anywhere else on the planet, or than I would be if I was re-incarnated in most parts of the world in most previous centuries, when life was on balance pretty brutal compared with today (or with a 4C warmer world).

    I can’t get depressed about it; rather, I see it as a matter of inconvenience i.e. the faster the climate warms in the next century, the faster people will need to adapt. Polar bears etc are neither here nor there incidentally – life is about people, and 99.9999999 per cent of people have never seen a polar bear in the wild in their life, and never will.

    So people in the future will be spending less time and money on adaptation if warming is slower – therefore I think reducing greenhouse gas emissions is sensible, other things being equal. Personally, I enjoy the simple things in life, hate waste and commute by bike, so I would be perfectly happy to live in a West where e.g. car usage and especially production of material goods were a tenth of what they are now.

    But I find the moral overtones of #557 rather sinister i.e. “it” is happening, if you disagree with “it” you are a “skeptic”, and the true path in life is to “do something about it”.

    There are two separate questions. Firstly, how sensitive is the climate to increases in CO2. Let’s say I am convinced by Schwartz (Aug 08) that the temperature increase for a doubling is 1.9 plus or minus 1.0C.
    http://www.rsc.org/delivery/_ArticleLinking/DisplayHTMLArticleforfree.cfm?JournalCode=EE&Year=2008&ManuscriptID=b810350j&Iss=4
    That doesn’t make me a skeptic because it is within the IPCC range, i.e. “it” is still happening. But is “it” not happening if climate sensitivity is say 1.7C, or 1C or even as low as 0.5C a la Spencer?. It’s obvious that polarising the debate is unhelpful, as is the “stages/phases of skepticism” model. Personally, I’ve always interpreted the data/atmospheric reality (clouds, interaction with oceans etc) as indicating climate sensitivity to be on the low side, and I’ve always been unimpressed by the arguments for urgent action to avoid “catastrophe”. I haven’t moved through any “phases” and don’t consider myself ignorant of the points “seen” by those who consider themselves fundamentally more enlightened than myself. At the same time, I am certainly open to a change in interpretation at any level – for example, the data from the Arctic in the last couple of years has added the equivalent of a couple of tenths of a degree to my interpretation of overall climate sensitivity.

    Second question, why should an individual be concerned about this. If we knew that (hypothetically) solar forcing was destined to increase global temperatures by 1.9C (or 3.6C or whatever) by 2100, and there was a way for society to reduce this figure, would an individual be morally bound to join a campaign to achieve this (because of the “rights” of people who will only have any existence decades hence, and (in most cases) as a result of a conscious decision by their parents to create them in a particular time and place?). Or is it purely for each individual to decide how significant (in existential terms) the potential upheaval to those future generations is, and whether the “rights” of the latter (i.e. to an even more superior wealth/quality of life) should trump their own.

  11. 561
    Ray Ladbury says:

    So, Chris, What are your feelings about having your great grandchildren born in a world where human civilization has collapsed and those who survive do so in bands of hunter-gathering tribes? Such a scenario cannot be precluded as a result of climate change.
    I don’t have a religious or spiritual bone in my body, but even I was inspired to near rapture when I saw tigers in the wild not 8 feet from me in an open jeep. Do you see no value in preserving the potential for such experiences for your own progeny
    If you feel no obligation to generations of humans yet to be born, I don’t see much point in trying to persuade you of anything.

  12. 562
    Chris says:

    Sorry if I got a bit carried away with my last post :) It’s just a strong statement of an alternative view, and I totally accept that many would vehemently disagree. That’s what the democratic process is for, right? (i.e. if concerted action for drastic emissions cuts is achieved through honest debate and with the support of a democratic majority then fine by me. I’m just defending my right to have a low interpretation of climate sensitivity and an optimistic view of people’s adaptability to various future scenarios.)

  13. 563
    Ray Ladbury says:

    Chris says: “I’m just defending my right to have a low interpretation of climate sensitivity and an optimistic view of people’s adaptability to various future scenarios.”

    You are entitled to your own opinions. You are not entitled to your own facts. Physical reality has a way of dealing harshly with people who don’t maintain at least a nodding acquaintance with it.

  14. 564
    Chris says:

    “What are your feelings about having your great grandchildren born in a world where human civilization has collapsed and those who survive do so in bands of hunter-gathering tribes?”

    Such a scenario can be precluded by human civilization regardless of climate change, period.

    “Do you see no value in preserving the potential for such experiences for your own progeny”

    I see a microscopic value in ensuring tigers thrive at exactly the same latitude in 100 years time as today for my great-grandchildren to visit on safari, compared to the value of everything else that matters in life.

    “You are not entitled to your own facts.”

    I’ll bear that in mind. I don’t think I ever suggested I was entitled to such a thing.

    “Physical reality has a way of dealing harshly with people who don’t maintain at least a nodding acquaintance with it.”

    This sounds grand, but is actually somewhat baffling on closer examination. I hope you’re not threatening me with being struck by a tornado?

  15. 565
    Ray Ladbury says:

    Chris,
    Your statement: “I’m just defending my right to have a low interpretation of climate sensitivity…” would seem to imply that this is a matter of opinion. It is not. It is an empirical fact, and it does not matter what you or I or anyone else “interpret” it to be. Everything I’ve seen so far from you seems to be constructed to reassure yourself that you needn’t take any action. Maybe try looking at the facts as they are rather than “interpreting” them.

  16. 566
    Jim Eaton says:

    Chris says, ” Polar bears etc are neither here nor there incidentally – life is about people…”

    What an alarming (and sad) view of nature. The world is not just about people. It is a living planet with millions of species. Aside from the fact that humans depend upon plants and animals for food, shelter, and even CO2 sequestration, many of us feel a moral imperative to not extinguish the wonderful biodiversity on Earth. Ecuador’s new constitution duly confers on ecosystems “the inalienable right to exist, flourish and evolve.”

    http://www.economist.com/world/international/displaystory.cfm?story_id=12432305

    {Capcha: “who delegate”}

    And while there are those of us, like Ray, who personally are thrilled when we see a tiger, polar bear, puma, or wolverine, these animals also are critical to the ecosystems in which they live. Removing top predators from an ecosystem leads to severe and unexpected changes, some of which can even be bad for people.

  17. 567
    Hank Roberts says:

    > the data from the Arctic in the last couple of years has added the
    > equivalent of a couple of tenths of a degree to my interpretation of
    > overall climate sensitivity.

    Your political agenda confers on you the claimed ability to do mental calculation, without showing your work, from a paucity of data, and obtain results of a precision far superior to anything published in the science journals.

    Does this ever worry you?

  18. 568
    Chris says:

    Ray,
    If you can point me to where I can find the “empirical fact” of climate sensitivity, it will be an understatement to say you will make my day (not to mention a million other people’s). I’m not going to enter into a pointless debate about your erroneous beliefs regarding my approach to climate science.

  19. 569
  20. 570
    Ray Ladbury says:

    Chris, are you positing that climate sensitivity has no objective existence? If you double CO2 concentration, temperature will change by some amount–that is an objective fact. Your opinion of it is irrelevant. The best estimate of that empirical constant is 3 degrees per doubling. Now perhaps you’ll suggest that if we clap and wish with all our might we can change it?

  21. 571

    2008 is by far the most interesting year for the Arctic region, a paper sometimes gets it right:

    http://www.thestar.com/article/519023

    There are 2 significant periods.. Cloud free spring, followed by extreme cloud cover till this day. I worked a great deal retrieving sun disk data last spring, upwards 700 observations almost every day, non stop, a regular spring has 200 or 300 obs interlaced with clouds, 2008 was the most exhausting spring since 2001. This fall is exactly the opposite. cloud cover was and is extreme, very few sun pictures acquired, the most cloudy fall since 2001. I got 20 pictures as opposed to 100 at the same time last year.

    Its a puzzle, but I have a working idea. A climate question….Does a La-Nina usually coincide with a cloud free Arctic?

    …….Congratulations Polarstern returning home, may you bring us valuable information….

  22. 572

    Following up on #571. Well what do you know? There is a link between ENSO and the Arctic Oscillation:

    http://www3.interscience.wiley.com/journal/112634578/abstract?CRETRY=1&SRETRY

    “it is robust”

    How can La-Nina affect the AO, or rather clear cloudless Arctic air? I suggest the following based on what happened this year. The Polar vortex this spring was extremely strong, with Tornado speed winds in excess of 210 knots at 30-10 mb. In this stratospheric hurricane, all aerosols
    get mixed thoroughly, continuously. While La-Nina reduced output of ice crystals/aerosols from the usual intense thunderstorm activity reaching the stratosphere during a normal year at the equator.
    In other words, fewer aerosols were kept in suspension, reducing cloud seeding much further below
    near the pole. When the vortex faded, in April, eventually whatever was mixed started to settle downwards in much calmer winds. Eventually contributing to the cloudiest season in memory.
    Its just an idea… It makes perfect sense with what has happened. The link with La-Nina and AO+
    may be driven in part by an aerosol shortage having its own feedback mechanisms, namely a colder stratosphere which drives a stronger vortex.

  23. 573
    Chris says:

    #571 “For example, fall air temperatures in the Arctic are at a record 5C above normal.”
    http://www.thestar.com/article/519023
    Evidence please?
    The best source I can find for particularly high temperatures is the NOAA animation, which has pretty colours filled in over large areas. But show me actual monthly records that have been broken come the end of the October and I will be convinced.
    (Btw to show I do volunteer a range of information, did you know air temperatures over the Antarctic Peninsula/islands to the north *actually* (unlike the Arctic) hit record highs for Sep 08 – see Bellingshausen, Esperanza, Marambio, Orcadas, Rothera http://www.antarctica.ac.uk/climate/surfacetemps/ There has clearly been very unusual weather there, and I would like to know more.)

    #570 Yes, it has an objective existence.
    “Now perhaps you’ll suggest that if we clap and wish with all our might we can change it?”
    I suggest that you’d better get clapping and wish for some significant further warming in the next few years if you’re so desperate to be right. Sorry, you know you’re right so there’s no need is there. Well at least I’m more open-minded, so if there’s a Super El Nino plus in 2010 for example then fine I’ll revise my view of climate sensitivity up some more.
    Wait…. I’m not allowed a view. I have to be bang in the middle of the “long-established (albeit subjective)
    estimate of 1.5–4.5C” as referred to in Hank’s link (#569).
    Well that’s fine: I’ve been trying to work out whether to special [this ain't spam] ise in meteorology or climatology in my career. Clearly there’s no point in pursuing the issue of climate sensitivity any more, and even if I produced a paper like Schwartz (the latest one)
    http://www.rsc.org/delivery/_ArticleLinking/DisplayHTMLArticleforfree.cfm?JournalCode=EE&Year=2008&ManuscriptID=b810350j&Iss=4
    which I actually think is one of the best papers I’ve read on climate sensitivity recently (I would think this even if he’d said 3C rather than 1.9C) I would be wasting my time.
    Great, I’ll start writing papers on meteorology instead. At least I can rely on the consistency of the numbers I’m feeding into my equations on the shorter timescales involved.

  24. 574
    Chris says:

    I’ve found the source for the “fall air temperatures in the Arctic are at a record 5C above normal” claim.
    It in fact refers to Oct-Nov for 2005-2007:
    http://www.arctic.noaa.gov/reportcard/images/essays/atmosphere/a2.png
    from
    http://www.arctic.noaa.gov/reportcard/atmosphere.html

    I thought Sep was fall as well, but I guess this would have reduced the average. I don’t have the NOAA map for Sep, so I can only infer that temperatures were lower from satellite data for “NoPol” i.e. ~ 60N-82.5N averaged for Sep 05-07, Oct 05-07, and Nov 05-07 respectively:
    +0.61C
    +1.27C
    +1.15C

    I’m not disputing that it was exceptionally mild over the East Siberian/western Beaufort side of the Arctic due to late open waters (I can see this from surface station data), but I would like to know how the +6C anomaly over the entire Central Arctic area was filled in.

  25. 575
  26. 576
    RichardC says:

    560 Chris, Schwartz’s analysis depends on climate equilibrium being reached in approximately 8 years. He forgets that the feedback caused by the melting of permafrost, ice sheets, glaciers, and clathrates takes decades to millenia. Heck, it takes hundreds of years for the oceans to overturn. An 8 year climactic response time?! Captcha says, “He Dirigeable.”

  27. 577
    Chris Colose says:

    Chris,

    see the Arctic 2008 report card for evidence
    http://www.arctic.noaa.gov/reportcard/

  28. 578
  29. 579
    Chris says:

    #576 RichardC

    Schwartz’s analysis depends on a measurable lag of 8 years. The more there are longer-term background lags that can’t be measured, the more we should now be seeing an accelerating trend in global temperature increases.
    Feedbacks from ice tend to decelerate as temperature goes up, since insolation at the retreating ice margins becomes progressively lower (hence feedbacks are already much lower now than coming out of an ice age).

    I just wrote a long reply re: Schwartz, but then realised that I’m interested enough in some of the issues it raises for them to provide a potential subject for my dissertation (also I might be reading them differently to him), so might be better for me to step back from arguing it via blog and give it a more rigorous examination.

    I would try not to pre-suppose any conclusions, rather, try to explore how the recent lack of acceleration in global temperatures can be reconciled with various models, and try to quantify what various scenarios for the next 10 years might imply about sensitivity (including rapid accelerations, it goes without saying.)

  30. 580
    Hank Roberts says:

    And discussed briefly earlier with additional links
    http://www.realclimate.org/index.php/archives/2007/08/friday-roundup-2/

  31. 581
    Hank Roberts says:

    Chris, make sure your long reply refers to Schwartz’s reply/update, not his original.

    http://julesandjames.blogspot.com/search/label/climate%20sensitivity
    page down to:
    Friday, May 09, 2008
    Comments about comments
    So our comment, Nicola Scafetta’s comment, Reto Knutti’s comment, and Steve Schwartz’ reply (combined to all of us) are all on line and some people seem to be getting very excited by it all. In his reply, Schwartz was quick to jump at Scafetta’s suggestion that the “pertinent time constant” can actually be diagnosed as about 8y, or maybe 12y, and seems happy to admit that his original analysis (5y) was wrong. Unfortunately, the reviewer(s?) and Editor gave him free rein to present a completely new analysis, based on a new model – hardly the point of a Reply, I thought – which is pretty much just as bogus as the original although the numbers don’t turn out quite as absurd….” (The original has links, q.v.)

  32. 582

    Evidence of a warmer Arctic 2008 fall atmosphere is also found other ways. Especially. if a cyclone from the North Pacific rolls in the High Arctic without cooling off much, bringing +10C air in mid-air 2000 miles away from the Pacific into the Eastern Arctic when temperatures should be -10 to -15 C. No question its warmer in the Arctic. The atmosphere must be judged as a whole, not from the surface only, not from a few upper air standard levels, all of it. Temperature variations of the entire atmosphere as a whole are far weaker than surface temperatures variations. A better trend can be devised from it….

  33. 583
    Chris says:

    #566 and #567 – missed these.

    Jim:
    “…”life is about people…”
    What an alarming (and sad) view of nature. The world is not just about people…”

    This goes to the heart of the matter. I love nature, and I also have a degree in politics during which I pondered deeply the questions of how society works/should work and what matters in life. And the fact is, democracy is government by the people for the people, and that is that. A world without people, but with wonderful biodiversity, would simply be pointless. The extent to which people prioritise biodiversity in policy-making, on the other hand, is their democratic choice. In any event, all these things you refer to – plants and animals as food/shelter/CO2 sequestration and biodiversity – will evolve but not necessarily suffer in a changing climate (especially if we work with the changes effectively). The predators you mention won’t necessarily die out just because their habitat gradually moves.

    “Ecuador’s new constitution duly confers on ecosystems “the inalienable right to exist, flourish and evolve.””

    Even though my politics have tended to be broadly left-wing, I fundamentally disagree with the way the language of rights is often used in modern discourse. There isn’t such a thing as an intrinsic right, only what people decide should be a right. But to give a right to an ecosystem, well that’s just abusing the language too far.

    Hank:
    “Your political agenda confers on you the claimed ability to do mental calculation, without showing your work, from a paucity of data, and obtain results of a precision far superior to anything published in the science journals.

    Does this ever worry you?”

    Hmmm, my “political agenda”. To be fair, my friend who knows more about climate change politics than me (and incidentally believes climate sensitivity to be worse-than-consensus) warned me that in America the politics are deeply polarised (much more aggressively than here in the UK), and therefore people who are very concerned about climate change will tend to view anyone who questions the seriousness of any aspect as being a potential “ally” of big business. I’m not used to this political set-up (hence why I was so offended when Wayne questioned my “motives” in an earlier post, until my friend explained the situation and i was *slightly* less offended).
    So I guess there’s some implication here that I’m caught up in one side of your polarised debate. I’m not.

    I guess your condescending remarks about my abilities stem from your opposition to my perceived political agenda. Because I bet if a climate scientist whose view of climate sensitivity was 4.2C for a doubling of CO2 remarked casually that “the data from the Arctic in the last couple of years has added the equivalent of a couple of tenths of a degree to my interpretation of overall climate sensitivity” you wouldn’t make the same remarks.

    Yes of course I’m not a climate scientist (yet). So of course I worry about the limitations to any conclusions that I draw. But the absolute one-sidedness of your approach (and many others), and my experience of people demonstrably getting things wrong on this thread who would claim to be more expert than myself, makes me realise the importance of standing my ground and trying to weigh up all evidence in my own time and using my own critical faculties, without being bullied into certain conclusions by people like yourself who often seem to add many harsh words but little true insight into the debate.
    (And for the record, I do try to correct outright “skeptics” when they get things demonstrably wrong too).

  34. 584
    Chris says:

    (OT, further to my last reply to Hank: politics was just part of my original degree. I have other more relevant qualifications and experience. In case you were wondering what a politics graduate was doing commenting about science at all! In any event, you’re partly right i.e. that I do over-stretch myself sometimes with my assertions. Maybe I just get too over-defensive when criticised. Or even over-sensitive if you excuse the pun! What I definitely do wrong is spending too long on a blog when I should be working…..But it’s been interesting, and I’m grateful to RC for providing a high-quality scientific forum to advance and test my knowledge)

  35. 585
    Hank Roberts says:

    Hey, the point is the climatologist is expected to publish such a specific number and defend it, not just blog it.

    Later readers here may well not know that when you write
    > the data from the Arctic in the last couple of years has added the
    > equivalent of a couple of tenths of a degree to my interpretation of
    > overall climate sensitivity
    you don’t mean calculated tenths of a degree C (or F), you mean “a little bit more” — and many readers may not even recognize that a “couple of years” of data isn’t a basis to change a sensitivity calculation even if you had made one. You write with such confidence that it’s potentially misleading.

    That’s my caution and reason for pushing for an explanation — it’s a science forum, claims made that look scientific deserve references.

    Climate scientists with a track record and publications we can look up may be relaxed making statements — we _can_ find their sources by looking up their work.

    Annan and Connolley are writing about science, not politics, in discussing climate sensitivity. They’re not in the US.

  36. 586
    Steve Bloom says:

    Re #583 (Chris): “In any event, all these things you refer to – plants and animals as food/shelter/CO2 sequestration and biodiversity – will evolve but not necessarily suffer in a changing climate (especially if we work with the changes effectively).”

    Have you looked at any of the science relating to this (here, e.g.)? Apparently not. In case it had escaped your notice, a major problem with the present anthropogenic clinate disruption is that it’s a much, much faster process than evolution.

  37. 587
    Chris says:

    #585 OK Hank I understand your point better now.

    Re: Schwartz I simply think his analysis provides extra insight into how it may be possible to infer sensitivities from empirical evidence. I’m not too interested in the exact figure (1.9 plus or minus 1C) that he comes up with at this stage and I agree that his apparent casualness with his key variable loses him credibility.

    The empirical evidence includes a ~0.40-0.45C increase in global temperature from the last cyclical peak over 60 years ago (to judge by Hadley/GISS). The question is why are we increasingly not seeing the acceleration required to achieve say a 2C or 3C increase to the next hypothetical “peak” of the natural cycle in 2070? This is what I want to address……
    Out of interest, what’s your own reasoning (as opposed to that quoted from links) as to why we shouldn’t see something like the following:
    1940s CO2 ~305ppm Temp 0.00C (baseline)
    2000s CO2 ~380ppm Temp +0.45C
    2050 CO2 ~475ppm Temp +1.00C
    And if we did what would it imply about climate sensitivity and projected temperatures for 2100?

    #586 I used the word “evolve” to refer to the ways in which people depend on animals and plants. There is only one reference to climate change in the entire article you link to.

  38. 588
  39. 589
    Hank Roberts says:

    Chris, if you’re asking me
    > Out of interest, what’s your own reasoning … as to why we
    > shouldn’t see something like …
    > …
    > And if we did what would it imply about climate sensitivity
    > and projected temperatures for 2100?

    I’ll settle for trying to read and understand what those actually studying this are publishing. This short list is very helpful:

    http://scholar.google.com/scholar?q=%22charney+climate+sensitivity%22

    For example:
    http://arxiv.org/pdf/0804.1126
    —excerpt—

    Atmospheric composition and surface properties in the late Pleistocene are known well enough for accurate assessment of the fast-feedback (Charney) climate sensitivity. We first compare the pre-industrial Holocene with the last glacial maximum [LGM, 20 ky BP (before present)]. The planet was in energy balance in both periods within a small fraction of 1 W/m2, as shown by considering the contrary: an imbalance of 1 W/m2 maintained a few millennia would melt all ice on the planet or change ocean temperature an amount far outside measured variations (Table S1 of 8). The approximate equilibrium characterizing most of Earth’s history is unlike the current situation, in which GHGs are rising at a rate much faster than the coupled climate system can respond.

  40. 590
    RichardC says:

    579 Chris says, “Schwartz’s analysis depends on a measurable lag of 8 years.”

    Schwartz’s paper depends on a “measurable” lag of 8 or 5 or 12 or any other random (but small) number of years. Noise drowns out the actual figure, so I’d say his whole paper is bunk. The actual number isn’t terribly important as it’s rather obvious that the atmosphere responds to forcings almost immediately. Schwartz’s point, that atmospheric feedbacks are quick, does not lead to his conclusion, that there is little warming in the pipe. Feedbacks tend to be step functions with long lag times. As you stated, 6000 years is a reasonable lag time for many forcings. I can’t imagine Schwartz being correct on any level. The radiative imbalance wouldn’t exist if he were correct. That he doesn’t address it speaks volumes, as it is just too obvious an issue.

    Chris says, “The more there are longer-term background lags that can’t be measured, the more we should now be seeing an accelerating trend in global temperature increases. Feedbacks from ice tend to decelerate as temperature goes up, since insolation at the retreating ice margins becomes progressively lower (hence feedbacks are already much lower now than coming out of an ice age).

    Your conclusion also does not follow. Methane release is a huge feedback. Arctic Ocean ice extent is a huge feedback. Schwartz (and you) are ignoring the largest feedbacks, and claiming it is appropriate to do so because they take longer than 8 (or 100) years to ramp up. Look at the thickness data for arctic ice. It has taken 50+ years for it to thin — and in all that period there has been no significant temperature feedback. Even today the melt of arctic sea ice is too late in the season to provide much feedback. But the last bit of ice goes, and all the feedback hits at once. A step function with a long lag. The methane release is the same. Nothing but “normal” release for 50+ years, then BANG! a sudden spike. You’re like the person who falls off a tall building and as he passes the 10th floor remarks, “So far so good!”

    Ice feedbacks do not tend to decelerate as temp goes up. Instead, they tend to have longer lag times. Depth matters, and it is only now that permafrost and clathrates are melting. You’re making the error of only counting very specific ice, that which is above ground and on land.

    Your comment about stuff being pointless without mankind erroneously implies that mankind makes a difference. What happens is technically pointless with or without mankind. The universe will eventually wind down and what happens on this planet will fade to nothing.

  41. 591
    Chris says:

    Don’t read anything into my lack of response. I’m got very busy just recently. It’s certainly not that I have nothing to say about statements like:

    #589
    “The planet was in energy balance in both periods within a small fraction of 1 W/m2, as shown by considering the contrary: an imbalance of 1 W/m2 maintained a few millennia would melt all ice on the planet or change ocean temperature an amount far outside measured variations”

    #590
    “But the last bit of ice goes, and all the feedback hits at once.”

    “BANG! a sudden spike.”

    “it is only now that permafrost and clathrates are melting”

  42. 592
    Robert S says:

    Does any one have an explanation for the latest squiggle on the Artic Sea Ice Extent graph. It seems to cover several days and was not there yesterday.

  43. 593
    Florifulgurator says:

    Chris,
    what you politics folks need to appreciate finally (this century) is that simple corollary to our planet being round: It is finite, i.e. has limits. Thus our life support system can’t evolve away from trouble forever. When it hits them limits, nature is no longer pointless to humans, for it will cause death and suffering (e.g. failing food supply) limited only by human population numbers.

  44. 594
    Sekerob says:

    Talking about the Antarctic I suppose. Yes i happened to take a copy when it was heavily pointing down and the next day this U turn showed. From communicating with Jaxa people they told me that around October 15 and also June 1-2 they change the algorithm to account for melt ponds which the sats do not seems to record correctly. They’ve smoothed their data now in this October but left the anomalous appearance for the past in their chart. Now, I dont know if the NSIDC does so to, for when i look now the U turn has disappeared now and the whole 2008 track has moved on up for the last weeks to be very close to the 1979-2000 mean.

    Just a guess.

  45. 595
    David B. Benson says:

    “Less Ice In Arctic Ocean 6000-7000 Years Ago”:

    http://www.sciencedaily.com/releases/2008/10/081020095850.htm

    [reCAPTCHA notes "of forcing".]

  46. 596
    Pat Neuman says:

    … “The 2008 season strongly reinforces the thirty-year downward trend in Arctic ice extent. The 2008 September low was 34% below the long-term average from 1979 to 2000 and only 9% greater than the 2007 record”. From:
    http://nsidc.org/news/press/20081002_seaice_pressrelease.html

    [... Similar to what was said in comment #5 (June 27) at link below.]
    http://www.realclimate.org/index.php/archives/2008/06/north-pole-notes/

  47. 597

    IR Downwelling played a significant role in this years melt. The clouds continue to puzzle, I was looking for Arctic Aerosol data, kind of scarce on the net. However I found this presentation from Andrew Vogelmann quite interesting:

    http://www.bnl.gov/bnlweb/pubaf/pr/PR_display.asp?prID=06-09

    There are so many, multi layered clouds now. Despite little direct sun light reaching the ice this past summer over the Arctic ocean, there was likely a small heat boost from high Aerosol content, a boost allegedly equal to man made Greenhouse gases… Present few Sun pictures I obtained are fuzzy with a lot of red rimming (water vapour or snow aloft) , recent Upper Air data consistently show 4 or more cloud layers, all indications of high aerosol content in the atmosphere. I continue with these observations and come up with a tentative conclusion on my website, I call the current phenomena Anvil seeding….

  48. 598
    Hans Eerens says:

    Dear all,
    I have been following your discussion for some time and I want to draw your attention to a recent article (23 October: GEOPHYSICAL RESEARCH LETTERS, VOL. 35, L20503, doi:10.1029/2008GL034813, 2008 by Lars H. Smedsrud et. al from Norway). In my opion they show convincing that the 2007 sea ice minimum was mainly due to increased sea ice export through the Fram Straight. Als they predicted correctly that due to the low sea ice export in June 2008 the 2008 sea ice extent would not be as low as 2007, see their summary below. According to their model calculation the sea ice should recover to their normal decline levels if the export should return to normal level. But their main uncertainty is the question what drives this increased export. So my question is does anyone have suggestions what we can expect for the future, export go back to normal, stabilize at this high level or even increase further.

    summary article:
    The present and future state of the Arctic sea ice
    cover is explored using new observations and a coupled
    one dimensional air–sea–ice model. Updated satellite
    observations of Fram Strait ice-area export show an
    increase over the last four years, with 37% increase in
    winter 07–08. Atmospheric poleward energy flux declined
    since 1990, but advection of oceanic heat has recently
    increased. Simulations show that the ice area export is a
    stronger driver of thinning than the estimated ocean heat
    fluxes of 40 TW. Increased ocean heat transport will raise
    primarily Atlantic layer temperature. The ‘present 2007’
    state of the Arctic ice could be a stable state given the
    recent high ice area export, but if ocean heat advection and
    ice export decrease, the ice cover will recover. A 2*CO2
    scenario with export and oceanic heat flux remaining
    strong, forecasts a summer Arctic open ocean area of 95%
    around 2050.

  49. 599
    Pekka Kostamo says:

    RE 598: Maybe of interest: http://www.agu.org/pubs/crossref/2008/2008GL034791.shtml

    According to this research, there has been long term changes in Arctic storm tracks and intensity, gradually increasing the export of ice through the Fram channel. It is also possible that water stratification is evolving in a way that reduces ice formation.

    Explains mainly the longer term trend. 2007 just happened to have much more of it. The first year ice issue then carried the impact into 2008. We will probably learn later if that was all (or if some heat was stored in the water as well).

    Seems to me that the global warming impacts are mostly indirect and dynamic like this. Subtle variations on quite conventional looking weather features, not so much direct interaction with warmer air. Probably not easy to explain to the public.

  50. 600
    hans eerens says:

    Dear Pekka (reply 599),

    Thanks for referring me to the article of 3 October (GEOPHYSICAL RESEARCH LETTERS, VOL. 35, L19704, doi:10.1029/2008GL034791, 2008 “Sea ice drift in the Arctic since the 1950s ‘ Sirpa Hakkinen et. Al.
    The article suggest that increased storm activity can explain the increased speed of ice (although I also expect that thinner ice will move faster). The article also give some insight what happens under water, out of our sight. Some changes are seen that can have a future impact. Some points I took out of the article:
    1) Salinity is increasing near the surface (approx from 30.9 in the 70s to 32.3 in 2007, suggesting an increase of 0.07 degree celsius in freezing pint)
    2) Fresh water layer with decreased salinity seems to decrease rapidly from approx 100 m in the 70s to 50m in 2007
    3) The zero degree temperature isobar in the artic ocean seems to rise rapidly from 250 m depth to 170m
    4) the deeper waters (>250m) seems to warm rapidly from 0.7 C to 1.1-1.5 Celsius.

    Thse T changes are disturbing when you realize the enormous amount of methane (hydrates) under the (relative not so thick) permafrost of the ocean bottom in the shallow water siberian coast, if released would effect climate change greatly (see also earlier articles this year on increased methane concentration in artic air (from 1.6 ppm global to 5 ppm) and under the artic seaice layer


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