Julienne Stroeve : Arctic Melt Since 1978 “cannot be easily explained away by natural variability”

Stroeve explains that highly reliable data on the extent of Arctic sea ice has been collected since 1978. From then until now, she has found clear evidence of a 30-year melting trend, which, she says, “cannot be easily explained away by natural variability.” But her work is even more notable for its findings about the speed of the change. Over this same 30 years, a relatively brief period, Stroeve has found that some 40 percent of the region’s summer (or more precisely, September) ice has melted.


I disagree. There is a clear relationship between PDO/ENSO and Arctic Ice.

We know that temperatures in Alaska are closely correlated with PDO/ENSO. Wouldn’t we expect western Arctic ice to be similarly affected?

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68 Responses to Julienne Stroeve : Arctic Melt Since 1978 “cannot be easily explained away by natural variability”

  1. Biobob says:

    highly reliable ?? explain then why there is such a large variance between JAXA AMSR-E, University of Bremen Arctic Sea Ice Extent, and NANSEN Artic ROOS- Sea ice extent ? Please explain away the observed ~ 450 degree observations from satellites re great lakes temps, for instance.

    Yes yes, I know,” to err is human”, isn’t it ? /sarc

    I can most easily explain anything away but that does not make me any more correct than you, Julienne. Until you produce your own experimental planet and repeatedly reproduce these results with well designed and interpreted experiments, all conclusions come under the category of “Wild Ass Guesses” rather than science.

    And Yes, Stephen’s observations have just as much validity as any others since they are all WAGs.

  2. John Edmondson says:

    “cannot be easily explained away by natural variability”

    Much more likely is that the models are wrong.



    Just gave those climate models another kicking.

    Lord Kelvin said “to measure is to know”. I wonder what he would have made of the climate models?

  3. peter says:

    even if the lower recent minima were anomalous when compared to other recent warmer periods, there is no way to link such anomalous lows with man-made increases in CO2

    and according to this study there is nothing anomalous with current polar ice relative to other warmer periods, and the observed (through proxies that is) polar amplification of global warming during past warmer periods fails to match that predicted to occur because of increased CO2.

    and there are plenty of other studies showing lower ice extents during recent warmer periods.

    • SteveS says:

      Hi Peter

      Your link is not working, can you post it again please.

    • Lazarus says:

      Peter, have you read the paper you linked to or just believed what someone told you it said?

      I cannot see anywhere where it supports your idea that there is nothing anomalous with current polar ice or that polar amplification fails to match that predicted.

      Can you give me some supporting quotes? All I can find is that observations are not in perfect accord with model projections, are they ever? And it does state that “future Arctic changes related to the continuing build up of greenhouse gases are likely to be much larger than at lower

      • Mike Davis says:

        Seeing how you have a reading problem:
        “Polar amplification of climate change is predicted by
        most climate models. However, the observational records
        of 20th century warming are not in perfect accord with
        model projections, an observation that has fed a lively
        debate (Serreze and Francis, 2006). During the 20th
        century, the planetary temperature increased 0.7 1C,
        whereas most regions of the Arctic record warming of
        1–3 1C over the same interval (Serreze et al., 2000). But,
        most of the warming occurred in summer months, whereas
        model projections indicate winter warming should dominate”

        Model predictions do not match reality so the warming in the recent past was due to natural conditions rather than an increase in GHGs
        Your WAGs are falsified!
        Something MIGHT happen in the future to change that but for your precious models are falsified.
        Another “Fingerprint of AGW” is not where it is supposed to be if the warming since 1950 was due to increased GHGs. Wrong fingerprints means wrong suspect. The Finger prints match what is expected from natural climate changes which woukd mean Natural weather is guilty and you are a fool for attempting to rewrite what was written!

      • Mike Davis says:

        This is the sentence that needs repeating:
        most of the warming occurred in summer months, whereas
        model projections indicate winter warming should dominate

      • Mike Davis says:

        And repeating:
        most of the warming occurred in summer months, whereas
        model projections indicate winter warming should dominate

      • Lazarus says:

        Mike I don’t have trouble reading – ‘not in perfect accord’ does not mean there is nothing anomalous with current polar ice.

        No one has ever said models are gospel – they are models. And this research still concludes “future Arctic changes related to the continuing build up of greenhouse gases are likely to be much larger than at lower latitudes.”

        If you accept the research that states ‘not in perfect accord’ ‘ do you accept this conclusion also or are you just cherry picking the bits you can spin to try and support your beliefs?

        I accept this as genuine scientific research and that it’s conclusions are based on the results they obtained, do you?

      • Mike Davis says:

        Model predictions are in opposition to what is observed in reality.

      • Mike Davis says:

        The signature in the Arctic was the unique signature for natural weather patterns and not ACC!
        Natural forcings will result in X and ACC forcings will result in Y.
        X was observed ACC was falsified!

      • peterhodges says:

        they have to put in their CAGW qualifiers to maintain funding and keep their jobs. note the non-sequitor and vague nature of the CAGW nods. whereas their conclusion, which follows from the body of the study, clearly contradicts CAGW prognostications.

        here is another one of my favorites: a study of antarctic contribution to sea level rise which concludes “Considering decadal accumulation variability, this translates to a net sink of fresh water of 42plusmn23 Gt/yr.”

        how’s that for cognitive dissonance

  4. PhilJourdan says:

    If you do not look, you will not find. When alamists have closed their mind to any other possibility, they stop looking. Much like PhDs do once they obtain the holy grail of education. They stop learning.

  5. suyts says:

    Jeez, this meme is sooo tiresome, too. The ice free arctic has been predicted since climate disruption was called global warming. Strange, 25 years and running and it still hasn’t happened, nor will it happen any time soon, but if it were to happen, it would mean absolutely nothing. 3 submarines surface at the North Pole surrounded by water. Norse farming Greenland, the USS Skate surfaces at the North Pole, explorers circa 1900 float their wooden boats through much of the arctic circle…….. All of this information seems to indicate that we have had much less ice in the Arctic than we presently have. We didn’t all drown, no tipping point crossed, nothing. Nothing happened. Now, humanity should worry about the ice melting? For what? Oh, yeh, the poley bears who seemed to manage quite fine during the earlier periods of less ice. Again, nothing happened.

    I truly hope all of the hand wringing about the Arctic ice is archived forever for posterity, too allow future generations to point, laugh and ridicule all of the alarmists ever worried about solid state H2O. And, I truly hope, future generations of such alarmists are forced to change their names upon pain of same ridicule and association with their forefathers.

  6. Biobob says:

    I am well and truly sick of this kind of bullcrap.

    My serious suggestion is to prosecute half a dozen of the most egregious offenders under eg USC title 1031 (Fraud) and sentence any convicted to the maximum allowed under this and other statutes eg 10 years and 1 million dollar fine.

    The instant pucker factor would put an immediate end to all of these kinds of unsupported claims.

  7. Biobob says:

    typo : title 18 1031

  8. Mike Davis says:

    In Climatology 20 to 30 years is long term observation and what went before can not be considered because that is prehistoric and anecdotal evidence is not as valid as WAGs.
    Just because thee is a photo showing a submarine at the North Pole does not mean it was taken at the North Pole.
    Don’t you remember the mock up used to fool everyone about the moon landings. 😉
    What would be considered fraud in the rest of the world is independent scientific research in academia. They are outside of the laws of mortals!

  9. It's always Marcia, Marcia says:

    “cannot be easily explained away by natural variability”


    def.–Cognitive Dissonance is the feeling of uncomfortable tension which comes from holding two conflicting thoughts in the mind at the same time.

    Dissonance increases with:

    -The importance of the subject to us.
    -How strongly the dissonant thoughts conflict.
    -Our inability to rationalize and explain away the conflict.

    Dissonance is often strong when we believe something about ourselves and then do something against that belief. If I believe I am good but do something bad, then the discomfort I feel as a result is cognitive dissonance.

    Cognitive dissonance is a very powerful motivator which will often lead us to change one or other of the conflicting belief or action. The discomfort often feels like a tension between the two opposing thoughts. To release the tension we can take one of three actions:

    -Change our behavior.
    -Justify our behavior by changing the conflicting cognition.
    -Justify our behavior by adding new cognitions.


    How cognitive dissonace applies to this topic:

    It is true that some people feel cognitive dissonance when trying to reconcile reality with their firmly held concept of reality. For them everythin g is global warming and to see any other cause for what is happening in the world is not easy for them.

    But until real evidence that what has happened in the last 30 years is anything other than natural variability we will have to come to terms with the reality that it was natural variability, regardless of how many ‘smart’ people around us say otherwise.

    For others of us we easily see natural variability. Why? Because what has happened in the last 30 years falls within the ranges of natural variability, not outside of it. Accepting of natural variabilty as cause is quite easy in such a case.

    • Mike Davis says:

      Then Holdren is right. We are now in a period that Climatologists and their followers are experiencing ACD Acquired Cognitive Dissonance.
      That would explain Chris, Tony Lazarus, et al and their position.
      Thank you for making that clear!

  10. Scarlet Pumpernickel says:

    http://upload.wikimedia.org/wikipedia/commons/c/ca/EPICA_temperature_plot.svg It was definitely warmer 2000 years ago why didn’t it crash into an ice age then, the arctic must have been very low too http://upload.wikimedia.org/wikipedia/commons/c/ca/Holocene_Temperature_Variations.png and before that there were other very warm periods. Generally if the Arctic retracts, Antarctica grows to buffer it.

    http://www.rationaloptimist.com/blog/unprecedented-warming If you look at the longer term especially Holocene Optimum 7000 years ago it was greatly warmer then today, the arctic ice was very very small. We can even see in Greenland http://jonova.s3.amazonaws.com/graphs/lappi/gisp-last-10000-new.png warming periods before Christ were much warmer then today. So I wouldn’t be worried about any Ice ages coming, the climate always changes and people are getting a bit excited as usual.

  11. Scarlet Pumpernickel says:

    http://www.rationaloptimist.com/blog/unprecedented-warming If you look at the longer term especially Holocene Optimum 7000 years ago it was greatly warmer then today, the arctic ice was very very small. We can even see in Greenland http://jonova.s3.amazonaws.com/graphs/lappi/gisp-last-10000-new.png warming periods before Christ were much warmer then today. So I wouldn’t be worried about any Ice ages coming, the climate always changes and people are getting a bit excited as usual.

  12. Scarlet Pumpernickel says:

    http://jonova.s3.amazonaws.com/graphs/lappi/gisp-last-10000-new.png Wasn’t the Minoan warming much more then today, was an Ice cap melted?

  13. Scarlet Pumpernickel says:

    http://www.rationaloptimist.com/blog/unprecedented-warming If you look at the longer term especially Holocene Optimum 7000 years ago it was greatly warmer then today, the arctic ice was very very small. Or didn’t it melt that time?

    • Mike Davis says:

      I have read studies saying the Arctic was ice free for months at a time during at least 8 periods since the Holocene period began. This was determined by wave action on beaches and drift wood found on those beaches that dated back to periods thousands of years ago. There are tree lines hundreds of Kilometers further north than now that were growing 800 years ago.
      I usually find this a good source:
      Along with:

      • Scarlet Pumpernickel says:

        Do you have the study of the tree line. It was much hotter in periods between 0BC and 10,000BC many times over. So why didn’t we TIP into 2012 lol?

      • Tony Duncan says:

        Mike did you look at the nature paper I sent you about YD
        I have ben reading other material which supports the idea that the huge temp changes were regional, and not glob\al phenomenon.
        Certainly that was a tipping point, that was pretty drastic, and some believe that it is part of the deglaciation process.

      • Scarlet Pumpernickel says:

        Maybe if we kill some witches like the Swiss/French did to stop the advancing glaciers in the middle ages the glaciers might grow again and threaten towns once again as the Church of IPCC commands?

      • Mike Davis says:

        Of course climate is regional! Global Climate change is only an average of the regional climate changes. Without understanding regional climate they are pissing in the wind with their fancy Game Boys. But regional climate changes are reflected in global averages for the period. There is lots of controversy surrounding the YD period both before and after with little understanding of the causes.
        You are attempting to divert from the issue because in case you did not know the YD period was primarily in the Arctic and we are talking about the Arctic. That makes any claims about regional a pile of BS. You asked about dramatic climate shifts in the Arctic and I pointed out the YD, You returned with BS about that being regional in the ARCTIC.
        At this rate my answers will become one line insults. You really should find a gentler place to spread your lies.

      • Tony Duncan says:

        I am sorry to deflate your grumpy mood,
        but what we were talking about was a 4° GLOBAL cooling in less than a century. At least that is what I remember talking about. I don’t ever recall asking about dramatic temp changes in just the arctic. that seems silly as I know that there can be quite dramatic changes regionally. I remember you mentioned that your conjecture was just as valid as a 4°warming, and that was about global temps as I recall. I said something to the effect that the temp raise was based on ACC theory, so the fact it had no precedent was not a liability to the prediction, whereas with your prediction there was no precedent for that level of change, within that time period.
        Once again I am hurt that you contend I am lying to you. At worst my memory is playing tricks on me.
        I am starting to get concerned about our relationship, and I really think we should get counseling to work this out. I know things are ricky between you and Chris, but you really shouldn’t take it out on me.

      • Tony Duncan says:
        November 17, 2010 at 7:21 am

        I am sorry to deflate your grumpy mood,
        but what we were talking about was a 4° GLOBAL cooling in less than a century.

        Somehow you think you are right Tony Duncan. You speak with such certainty. So give proof of your certainty, and while you are at it write up a paper about it and submit it for peer review. Let’s see what they reply to you about your certainty over global temperatures during the Younger Dryas. You are the most certain person in the room about temperatures 12,000 years ago.

      • Tony Duncan says:

        Fascinating that you consider my posts certain, when I clearly posted that I might be having problems with my memory.
        And you are taking my line away from me, which I rather resent.
        “Write it up and submit it to the peer review process”
        I am not sure why I would need to present for peer review an article about reading papers that doubt that there was a global temperature cooling of 8° during the Younger Dryas. (the link Mike sent me where Don Esterbrook says that).
        Or my recollections of a podcast interview with Freeman Dyson. Frankly, I don’t think any respectable journal would consider either paper worth reviewing.
        Whereas the hundreds of proofs that ACC is wrong I see here every day, certainly should be written up for peer review. They are all based on real science and so obviously right, they would have to be accpeted
        Everyone here is so CERTAIN that ACC is wrong, and you have the proof of that in every area research, that I bet within 6 months all those climate scientists would realize what idiots they were, and bow to the intellectual superiority of you purveyors of truth.
        You all say it is so obvious over and over again. how could the whole thing NOT fall apart very soon. I mean you are basically saying this is Lysenkoism, and that fell apart after stalin died

      • Tony Duncan says:


        and to be serious, I am NOT certain about ACC. There are assertions and links to research that are put on here that I do not have answers to. It is possible that you are right and ACC is wrong. I am not a scientist and not an expert, and I have never pretended to be either.
        However I do not accept evidence against ACC just because I see it here and you all laugh about what idiots those scientists are. As i said, i know a number of scientists including climate scientists, and NONE of them are idiots, none of them are grant hungry opportunists and none of them are sycophants who will not question something if their authorities tell them not to
        I want to see what the responses are from expert scientists to the assertions or research before making up my mind.
        I do not have the time or the standing to interrupt the life of people who are not close friends every time Steve posts something. And there are clearly things that are irrationally believed by some people here, because while not an expert I do know SOME things.
        I am not trying to convince any one here, which is why I don’t care how I am attacked. It doesn’t discourage, me, it doesn’t make me mad, As I have said, this is fun to me. I do learn things on this site and the points made that seem valid I do vaguely store to eventually check out.
        If you are right., it will eventually be something I won’t be able to deny, and you can take pleasure in knowing that the truth finally convinced an believer in ACC. It just won’t happen with me just believing only your facts, without seeing what the response of the scientific community is.
        the fact that your characterizations of scientists is totally inconsistent with my actual interactions with them will make it harder though 😉

    • Mike Davis says:

      I cleaned out a bunch of PDFs and links when I changed browsers. I found a lot of research papers at CA and at Hoffman’s site.

  14. Brego says:

    Why is there no photo of Julienne to go with this post? Damn, she’s a looker!

  15. But her work is even more notable for its findings about the speed of the change. Over this same 30 years, a relatively brief period, Stroeve has found that some 40 percent of the region’s summer (or more precisely, September) ice has melted.

    And the relevance of that would be?

    Has she proven that this same thing has not happened before? I hope she didn’t just assume it has never happened before. But I have a sad feeling she did.

    • I think it must have happened many times before, especially during the Medieval Warm Period, a time period which I am particularly referring to when I question the speed up alarmist claim in the quote and how it could have easily happened before.

      • Mike Davis says:

        The periods that before the MWP made the MWP look cold. Some of the cooling periods were warmer than the MWP or the CWP

      • Drawing conclusions about the long term from 30 years of data is unscientific, or even 100 years. Why? Because 30 or 100 years are not long term. I’m sure Julienne Stroeve knows that.

        I say again, it really is a shame that there weren’t satellites recording Arctic ice data for the last 10,000 years. If we had such data then we could get a better picture of what’s happening at the North Pole.

        I am not impressed by what 30 years of satellite data is showing. To only use that time period to conclude things is cherry picking.

      • Mike Davis,

        I see what you are saying. I hope this sad period of abuse of common sense in science ends soon. I hope scientists are on tv soon saying all this ‘global warming’ talk is exaggeration gone wild.

      • Scarlet Pumpernickel says:

        That’s true, the peak of the MWP was actually equal to the cold period during the Minoean warming.

  16. Mike Davis says:

    Sorry AAIM:
    I thought i was writing to scarlet pumpernickel. I get your two icons mixed up. I would not be as generous as you to call 30 years to base a trend on “Cherry Picking”. It is deliberate falsification. I can find evidence of what represents long term weather patterns. If I can find it any one can because terms like PDO, AMO being related to weather patterns are all over the place. Even NOAA NCDC has a web site dedicated to ENSO and PDO so there is no reason for them to continue using 30 year average of the mean as a base for climate. It is obviously not being sloppy or ignorant. One of my customers was DRI at University Of Nevada Las Vegas. Some showed a lack of comon sense but that is every where you look. It goes beyond oversite!
    Science is being pulled into the gutter and since the real scientists did not speak out it may be to late for the current generation in that field and those just entering. The longer they wait the harder the crash and it will not be pretty.
    It has got to be just another bubble and we have all seen what happens to bubbles!

  17. Scarlet Pumpernickel says:

    Greenland ice cores show it was warmer in the past, the Arctic didn’t die, everything survived

  18. Scarlet Pumpernickel says:


    Greenland temperatures just starting to get closer to 1920s-1930s levels

  19. AndyW says:

    “We know that temperatures in Alaska are closely correlated with PDO/ENSO. Wouldn’t we expect western Arctic ice to be similarly affected?!”

    Maybe, but most ice is being lost on the Siberian side in the summer now, perhaps the western side is adding a bit on top.


  20. Gerald Machnee says:

    Is not some of the global warming due to temperatures in the high arctic, fill-ins included?
    So if the arctic cools, do we still get “global warming” due to inflated fill-in grid points between Eureka and Eureka?

  21. PhilJourdan says:

    Tony Duncan says:
    November 17, 2010 at 4:45 pm

    Everyone here is so CERTAIN that ACC is wrong, and you have the proof of that in every area research,

    It would benefit you to not keep creating laughable strawmen that have no basis in reality. Indeed, I doubt that most here are “certain” about ACC (or the lack there of) or much of anything Scientific! That is what makes us skeptics (versus the religious faithful that rely on concensus and blind allegiance to a party line – because someone told them the “science” was settled).

    • Tony Duncan says:

      Ah Phil,

      you caught me in my terrible straw man argument
      Please show me the comments from any of the skeptics here that indicate that they consider that ACC might be real, or that some evidence does support the theory.
      and you can of course use examples from any of the collection of blogs ;-).

      of course I imagine I have TOTALLY misunderstood your comment, and you shall now enlighten me.

      But I am interested in who these religious dupes are that are totally beholden to the party line. You can’t mean me or Chris or Lazarus, since non of us has ever expressed anything remotely resembling that. so I must have missed those posters.

      • Mike Davis says:

        My comment has been that Anthropogenic Climate Change Caised by humans releasing GHGs into the atmosphere is at best a bit player in the overall long term regional weather picture. research and historical records show that most likely ACC is an observer on the side lines. You have X number of players that suit up for the game and one is the water boy ACC is maybe the water boy or mascot!
        If you are actually referring to Catastrophic Anthropogenic Climate Change. Such as the human factor will lead to unprecedented extreme weather events. I am your man for claiming you are out of your Friggin mind, high on drugs , or a cult fanatic.
        I can find evidence that human land use and land change leads to regional changes in weather patterns but that is not related to releasing GHGs into the atmosphere. I can show you where Waste heat has changed weather patterns. I can show you where poor siting issues make it appear that humans are the cause of changed weather patterns in excess of UHI.
        There is lots of reliable historical information to compare today’s weather to that of the past that provides evidence that the past was more extreme that the current period and just within the last 1000 years. It was probably warmer 1000 years ago than now. If the models are compared to garbage to train them then the output is no better than garbage. The output can never be better than the worst input. If they are uncertain of the cotribution of clouds then they wasted the entire project because the output will always be uncertain and a WAG at best.
        A theory has to have a unique signature or foot print that can only be found if the theory is true. The signatures claimed by the modelers have not been found but the unique signatures that would be seen if natural forcing are the primary factor in weather are there for all to see where ever one should look for that unique signature.
        Do I deny ACC? NO
        Do I deny CACC? not only yes but H### YES!
        I AM A REALIST!

      • Tony Duncan says:


        that is a reasonable position to take. Can you show me the peer reviewed literature that supports this position.
        Is it a consistent position that a number of scientists hold?
        If what you say is accurate then there should be a clear set of verifiable markers that show current warming fits this theory and should be available and compete quite effectively with ACC theory.

  22. Pingback: ENSO, Air Temperature and Sea-Ice « clearscience

  23. peterhodges says:


    Tony Duncan says:
    November 18, 2010 at 4:12 pm


    that is a reasonable position to take. Can you show me the peer reviewed literature that supports this position.
    Is it a consistent position that a number of scientists hold?

    i would guess, no

  24. Mike Davisw says:

    I guess you have not read Lindzen, Spencer, and a host of other peer-reviewed researchers that hold this position. There is not a “CONSENSUS” among REALISTS each tries to find what provides the best explanation based on their experience.
    Sorry Peter the answer is yes. There are books available to read about real climate history of the Globe!

    • Tony Duncan says:


      I actually have read, Lindzen, Spencer, Michaels, Singer, Soons and Baliunas, McKittrick, McIntyre, Pilke (both), Curry, and a few others that have issues with ACC. I have also read the responses to their views. Without knowing enough of the science involved, the rebuttals to these attacks/differences seem convincing to me. On issues where I DO understand the science, the rebuttals are devastatingly convincing. On social psychological issues, such as Pilke Jr., and Curry, I agree with aspects of their criticism, but in general don’t think they know what they are talking about, Pilke, because of leftist ideological blinders, and Curry, because I believe she is naive about the political aspects of the issue.
      You say that there is no consensus among realists because each is looking for the explanation that fits their experience. That is possible, but I think it also likely that it is because each knows things that would undermine arguments of the other. When is the consensus going to emerge that will replace the ACC paradigm? We have 30 years of accelerating research, and literally thousands of scientists around the world who are involved in some aspect of climate change. Scientists, especially young ones who want to do something important, are much to smart to hold onto a theory that is not tenable when there is a competing theory that is tenable and explains the facts better.
      You are unlikely to convince me or anyone without an ideological disposition against ACC until there is a viable consistent theory that ACC can be measured against. As I have said repeatedly, I know some climate scientists and the characterization of their beliefs, attitudes, intelligence and gullibility are totally incompatible with the people I know.

  25. clearscience says:

    I believe that this post is addressed on my blog but I will summarize for you. ENSO is not strongly related to Arctic Sea Ice melt just like 5-year running means of ENSO do not match global temperatures which are highly correlated to arctic ice melt.

  26. Julienne Stroeve says:

    Interesting, I just saw this post as I was searching for something else online. Steve, I think you know I was talking about the summer ice cover in that article, and yet you show April sea ice? It would be great if some simple index of climate variability such as the PDO, ENSO, AO, NAO, etc. could explain the changes we’re seeing in the ice cover, but unfortunately that is not the case and I don’t see how you have proven that these natural modes of variability (and I say natural loosely here, since you cannot discount that changes in these modes of variability may in turn be forced by climate changes, such as more open water in September in the Arctic) are the dominant factor in explaining the September sea ice trend.

    I believe I have sent you in the past some figures that show the acceleration in the summer sea ice loss, if not, I will send them to you (or our synthesis paper in Climatic Change that is in press) so that you can see our analysis of the acceleration in the decline in the summer ice cover.

    I notice that you haven’t talked much about the 2011 ice cover this year. Ice extent has been below that in 2007 the last few days. I don’t put too much importance on that since we know that summer circulation is still an important factor in shaping the end of summer ice extent, but the summer melt season is starting out with more than 2 standard deviations less sea ice extent again this year. What is your explanation for why this is, given your theory that the PDO/ENSO explains the April sea ice variability?

    • Julienne,

      As you know, most of the loss of multi-year ice occurred between 1988 and 1996 when it blew out of the Arctic. I’ve written quite a few articles about the thickening of the ice in the Arctic Basin over the last three years.

      Looking at the NSIDC maps, I see that most of the “missing ice” you are discussing is around Newfoundland and Quebec. How does that affect the summer ice in the Arctic basin?

      • Julienne Stroeve says:

        Steve, I did say in my posting that just because we’re currently two standard deviations below the mean right now, that doesn’t necessarily mean we’ll have a new record low, the summer circulation pattern remains important. But what it does imply is that more of the ocean surface is exposed by sunlight earlier than normal, allowing for enhanced lateral and basal melting to start to affect the ice.

        It is incorrect that most of the MYI loss occurred between 1988 and 1996. Taking an average of the March MYI fraction from the Arctic Basin (so I’m ignoring the E. Greenland Sea, the CAA, and the regions of FYI, such as the Bering Sea, Baffin Bay, Labrador Sea, etc.) from 1979 to 1987 gives you a mean of 4.89 million sq-km. From 1988-1996 the mean MYI cover is 4.32 million sq-km. From 1997-2011 it is 3.58 million sq-km. Obviously more MYI has been lost post 1996 than during the positive AO period of the late 1980s, early 1990s.

        I wouldn’t trust the model results on the Arctic thickness distribution. Best to look at the Cryosat 2 data, or the Icebridge data to see how much the ice has thickened the last 3 years. Or other field studies that are measuring ice thickness.

      • Mike Davis says:

        Do you have the satellite records for the period from 800 to 1700 so we can compare natural ice fluctuations to what some consider human induced ice patterns over the last 60 years. Even the satellite records from the 40s and 50s would be helpful!
        Less that a couple of thousand years is just variable weather patterns. Regional climate is defined by long term variable weather patterns. That means that climate is CHANGE. The climate normal is changes in weather patterns. Averages tell us nothing about regional climate.
        Your ice is doing just fie and is within historical limits and doing what it did in the past during similar periods.

  27. Anything is possible says:

    Mike is making a key point here : Without historical data, it is impossible to put the changes observed since 1979 into any sort of accurate context.

    Back in the day, I can recall a young, enthusiastic Climate Science undergraduate being repeatedly cautioned against jumping to wild conclusions based insufficient data. “It takes seven swallows to make a summer” was the memo that eventually stuck in my mind.

    Sometime between 1993 and 2011, Climate Science consigned that memo to the dustbin of history…….

  28. Julienne Stroeve says:

    Mike, we have earlier records from satellite, ship and aircraft that allow us to go back to 1953 with good reliability. Before that the record is rather spotty. But if you want to go back the last 54 years, then what is happening today is unprecedented in that record.

    Sorta a silly question to ask if we have satellite data back to 800-1700 since you know we don’t. What we have instead are sediment cores, travel route knowledge from the local people passed down from generations to generations through their songs, stories, drawings and written word, and other paleoclimate reconstructions. Depending on how much you trust paleoclimate work, and the fact that if the Arctic Ocean would have been ice free in the last 2000 years, people living in the region would have probably recorded this in some fashion, since as long as man has been civilized, they have been using boats (by 4000 BC man had learned to create boats with spoonlike shapes), then you would have to come to realize that what is happening today has not happened for at least a few thousand years.

    People have inhabited various regions of the Arctic for thousands of years. The earliest known evidence of humans in the Arctic is from 40,000 years ago in Western Siberia. The earliest presence of peoples in North America dates back 15,000 years when humans inhabited Alaska. Researchers believe that Greenland and the Canadian Arctic were settled 11,000 years after Alaska, approximately 4,000 years ago.

    So just because we don’t have satellite data from 800 to 1700 does not mean we don’t have some idea of what the ice conditions were like back then.

    • Mike Davis says:

      And current conditions are not unprecedented in any way. You forgot about tree lines and mapping that was carried out by early explorers that show inlets that were until recently ice flows. No we do not have accurate records to say we are experiencing any abnormal climate conditions at this time or for the last 150 years. There are records that show greater variations in the Arctic region than we are experiencing today and some of your examples are just that. Earlier settlers are the source of knowledge of lack of sea ice and tree lines closer to the Arctic Ocean and also lack of ice shelves in the Arctic that exist today.
      You need to read about the Vikings and their interactions with the Inuit in the region when the settled Vinland/ Newfoundland. It was called Vinland because they were able to cultivate their version of grapes there. Much warmer than today!

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