Ice Follies and Hiding the Decline

Anthony Watts at Watts Up With That points out a curious thing about reporting of Arctic sea ice extent.

It seems that IPCC reports after 1990 and current federal government agencies show graphs of the Arctic sea ice extent that all begin in 1979, see example below:


This gives the impression that Arctic sea  ice has been in steady decline. But the first IPCC report in 1990 included pre-1979 satellite data which shows that prior to 1979, Arctic sea ice was much lower in extent, about equal to what it is now (page 224 of IPCC FAR WG1):


If these earlier data were included in current reports, it would make the Arctic sea ice variation appear cyclic rather than declining.  Could it be that our politically correct, cherry-picking climate “scientists” are trying to hide the decline?

By the way, study of sediment cores spanning the last 9,000 years found that “that sea-ice cover in the western Arctic Ocean has varied throughout the Holocene. More importantly, there have been times when sea-ice cover was less extensive than at the end of the 20th century.” And, the study authors write: “It is important to note that the amplitude of these millennial-scale changes in sea-surface conditions far exceed those observed at the end of the 20th century.”


McKay, J.L., et al., 2008, Holocene fluctuations in Arctic sea-ice cover: dinocyst-based  reconstructions for the eastern Chukchi Sea, Can. J. Earth Sci. 45.

See here how the “ministry of truth” is revising the historic temperature record to make the past seem cooler and the present warmer.

See also:

Arctic tipping point, will there be an ice-free Arctic



  1. The observant reader will note that comparing the two graphs, in the overlapping period the anomalies are simply not comparable. It is obvious that the pre-satellite data are less reliable than the satellite, which has been compiled and verified against observations by organisations such as the National Ice Service.

    The insinuation that this is part of a cyclic pattern is baseless. Vinje and Goosse have found: “Both observations and simulations indicate that natural forcing is dominating the climate change from 1750 to mid 20th century, and that anthropogenic (human) forcing becomes increasingly dominant thereafter.” That was back in 2003, since then the science has strengthened that conclusion. Jakobsson 2010 finds that sea ice in the mid to early holocene (as late as 6000 years ago) was substantially lower than at present, however then sunlight at 65degN in July was almost 1/10 higher than today – that was why the sea-ice was lower. In 2009 a team lead by Kaufman released a study entitled: “Recent Warming Reverses Long-Term Arctic Cooling.” The title of which speaks for itself, for the last 2000 years the Arctic has been cooling, only recently has it started warming. In “The recent Arctic warm period” Overland and colleagues show that the 1940s warm period was a regional warming of parts of the Arctic whereas the current warming is widespread. And Johanessen “Arctic climate change: observed and modelled temperature and sea-ice variability.” shows that while models reproduce warm periods like the 1940s Arctic warming at different times, all the models reproduce the recent warming: showing that the recent warming is a forced response to global warming, whereas the 1940s warming was mainly internal variability of the climate.

    1. Cristian, Thanks for the very lucid and informative comment. You have proven to be one of those observant readers. Jon’s continuous efforts to portray climate scientists as a group of corrupt conspirators working to hide the truth, is truly beyond the pale. JP

      1. John,  the cllimategate emails proved that some climate scientists where indeed corrupt conspirators.

      2. You have quite the low bar for proof of bad climate scientists, and yet a very high bar for evidence for climate change. The only good climate scientists are the ones that agree with you.

        When scientists say the evidence is overwhelming the natural forcings, they are able to back it up with ample evidence.

      3. Jon, “climategate” proved nothing of the sort. Of course you are aware that four different independent commissions reviewed the emails and found that there was no evidence of scientific fraud, manipulation of data, or conspiracy of any sort. So your above is simply wrong. Further it is a canard. You are continuing to allege scientific fraud on the basis of zero evidence.

        My suggestion is this: if you are convinced of scientific fraud or conspiracy to alter or fraudulently conceal scientific data to manipulate findings, then you should identify the scientists that you claim are guilty of this, and file a complaint with their employer. Don’t hide behind “some climate scientists.” Who are they? And are you accusing them of fraudulent behavior?

      4. David,

        Given the scope of the science and the number of scientists involved, to claim that there is a conspiracy is indeed ridiculous.

        For there to be a conspiracy it would need to cover so many disciplines and so many scientists that it flies in the face of human nature. It’s worth noting here that people get Nobel Prizes for overturning accepted science. As of this date nobody has overturned the science that humans are emitting CO2 (and are causing the increase in atmospheric CO2), that this should warm the planet (the science of which is over 100 years old), and we are observing warming (surface stations, ocean, satellite, boreholes and a plethora of supportive evidence).

        What the emails show are the reasonable attempts of professions to keep ill considered nonsense out of their profession. This happens in all branches of science and engineering.

    2. Christian, you may be confused by the different vertical scales, but the graphs are very similar.  It is my understanding that the data from 1975 is also satellite data.  Mckay, cited above provides geological evidence for an Arctic oscillation with resulting cycles of sea ice. Presumably the Arctic Oscillation is still working, and you have presented no evidence that it is not nor that CO2 is suddenly the major forcing.  Even the low ice level in 2007 is attributed to winds of the Arctic oscillation according to NASA; see: Christian, please give full citations to your references, otherwise, how do I know you are not just making them up or misinterpreting  what was said?  At least then I could check them to see what was actually written.

      1. Jonathan Duhamel,

        Look again at the figures you posted.
        Figure 1, 1979 – 1990 anomalies strongly biassed to the positive.
        Figure 2, 1979 – 1990 anomalies clearly bipolar.
        So I still don’t think they’re compatible as presented.
        The Arctic Oscillation (AO) was in a largely positive mode during the 1990s. Following its return to more neutral values researchers such as Vinje concluded:”…we should expect a reduction in the ice efflux, and, a thickening of the ice in the Arctic Ocean during the next decade. A future thickening of the ice is also predicted by Polyakov et al. (1999) in connection with an observed reversal to an anticyclonic ice circulation in the reservoir toward the end of 1990.”

        That did not happen. Indeed the correlation between the AO and sea-ice has fallen. This is no surprise, in 2008 Zhang et al published research (Zhang et al 2008a) showing that the AO had been replaced as the first EOF of Arctic atmospheric variability by the Arctic Dipole (AD). The AO was not a player in 2007’s crash, it was the AD which caused the massive reduction of sea ice in the Pacific sector*. Wang et al 2009 shows that the AD is a major driver to sea ice loss, Watanabe et al 2006 shows that it is reproduced in models, and Overland and Wang (also Francis – personal communication) show that it’s emergence to dominance has occurred in response to Arctic warming.

        Finally the crash of 2007 would not have happened without years of volume loss (Kwok & Rothrock) preconditioning the sea ice to be vulnerable to the weather of 2007 (Zhang et al 2008b).

        * Here I am combining figure 3 of Wang 2008, NCEP/NCAR analysis and a paper by Zhang entitled “What drove the dramatic retreat of arctic sea ice during summer 2007?” which mentions anomalous winds but does not mention the AD, although figure 3 of Wang shows the strongest recorded AD and the sea level pressure and 500mb geopotential heights both support the idea that the AD was the cause of the anomalous winds.
        References for my two posts. I was a sceptic but after starting to read the science I am no longer. I now study the Arctic because it’s fascinating and exciting. I have read all thee studies and many more.
        Jakobsson, 2010, New insights on Arctic Quaternary climate variability from palaeo-records and numerical modelling. Quaternary Science Reviews.
        Kaufman, 2009, Recent Warming Reverses Long-Term Arctic Cooling. Science.
        Kwok & Rothrock, 2009, “Decline in Arctic sea ice thickness from submarine and ICESat records: 1958–2008.” GRL.
        Overland, 2008, “The recent Arctic warm period”. Tellus.
        Overland & Wang, 2010, “Large-scale atmospheric circulation changes are associated with the recent loss of Arctic sea ice.” Tellus.
        Vinje & Goosse, 2003, “ICE EXTENT VARIATIONS DURING LAST CENTURIES.” POSTER at Final ACSYS Science Conference.
        Wang et al, 2009, “Is the Dipole Anomaly a major driver to record lows in Arctic summer sea-ice extent.”
        Watanabe et al, 2006, “Arctic dipole anomaly and its contribution to sea ice export from the Arctic Ocean in the 20th century.”
        (Xiandong) Zhang et al, 2008a, “Recent radical shifts of atmospheric circulations and rapid changes in Arctic climate system.”  (Jinlun) Zhang et al, 2008b, What drove the dramatic retreat of arctic sea ice during summer 2007?

      2. Thanks for the citations and links.  I will read the papers.

        Masahiro Ohashi and H. L. Tanaka, 2010, Data Analysis of Recent Warming Pattern in the Arctic, SOLA, 2010, Vol. 6A, 001−004, doi:10.2151/sola.6A-001.

        In this study, we investigate the mechanism of the arctic warming pattern in surface air temperature (SAT) and sea ice concentrations over the last two decades in comparison with global warming since the 1970s. According to the analysis result, it is found that the patterns of
        SAT and sea ice before 1989 are mostly determined by the Arctic Oscillation (AO) in winter. In contrast, arctic warming patterns after 1989 are characterized by the intensification of the Beaufort High and the reduced sea-ice concentrations in summer induced by the positive ice-albedo feedback.

        It is concluded that the arctic warming before 1989 especially in winter was explained by the positive trend of the AOI. Moreover the intensified Beaufort High and the drastic decrease of the
        sea ice concentrations in September after 1989 were associated with the recent negative trend of the AOI. Since the decadal variation of the AO is recognized as the natural variability of the global atmosphere, it is shown that both of decadal variabilities before and after 1989 in the Arctic can be mostly explained by the natural variability of the AO not by the external response due to the human activity.

      3. Re Ohashi & Tanaka, I’ve encountered this paper previously, it’s a regular in the denialist echo-chamber, however I am unimpressed. The full paper is available here: an abstract is of no value.

        They repeatedly refer to Autumn (SON) warming as due to ice albedo when most of the central Arctic is in darkness during most of the Autumn and other papers (e.g. Screen & Simmonds 2010), and referal to NCEP/NCAR, shows that the warming is associated with open ocean freezing and thinner ice promoting heat fluxes into the atmosphere.

        They carry out an EOF analysis of the the multi-model mean. Firstly the multi model mean is interpreted as the forced response, this interpretation is reasonable for the mean of ensembles from the same model but for an ensemble of different models it runs the risk of introducing the effect of biasses from different models, thus smearing the result. They interpret the smearing of EOF1 as support for their idea that models do not produce the AO correctly, however the smearing is due to using the multi-model mean of different models. It is worth noting that all but one (MIROC medres) of the models they have used were rejected by wang & Overland as not correctly producing the seasonal cycle of sea-ice in the study “A sea ice free summer Arctic within 30 years?”

        They use regression to show the patterns of ice change associated with the AO and Beaufort High (BH), however they then draw the erroneous conclusion that the retreat of ice being common to all the areas concerned is due to the combined effects of the AO and BH. This conclusion is erroneous because the comparison of the bottom panels of figure 4 shows that the combined recession due to AO and BH factors covers the whole of the peripheral Arctic basin – the conclusion does not rule out other factors such as GW driven ice loss.

        Finally with regards their key finding of a recent low AO temperature signature in Winter: In “Arctic warming, increasing snow cover and widespread boreal winter cooling” Cohen et al explain how the AO is being driven into a negative state precisely due to reduced Arctic sea ice, this is causing a region of Winter cooling over Europe and Eurasia. So whilst you present Ohashi and Tanaka as showing that the changes are natural in origin, they are actually a feedback from the loss of sea-ice. Gillett et al shows that the changes are being driven by human activity.

        Cohen et al, 2012, Arctic warming, increasing snow cover and widespread boreal winter cooling.
        Gillett et al, 2008, Attribution of polar warming to human influence.
        Screen & Simmonds, 2010, The central role of diminishing sea ice in recent Arctic temperature amplification.
        Wang & Overland, 2009, A sea ice free summer Arctic within 30 years?

      4. Jon, after analyzing the evidence provided by you, and then examining that provided by Christian; it’s clear to us all who is “confused”. JP

  2. If I could add to Christian’s already excellent work. I just recently posted this over to “the environment site”.

    Ice is the canary in the coal mine.…2246787/print/Arctic sea ice in longest decline seen over past 1,450 years: studyBob WeberThe Canadian PressPublished Wednesday, Nov. 23, 2011 5:52PM ESTLast updated Thursday, Nov. 24, 2011 8:49PM ESTResearch published in a top scientific journal says Arctic sea ice has declined more in the last half-century than it has any time over the last 1,450 years.The study, which gives the most detailed picture ever of the northern oceans over the previous millennium-and-a-half, also concludes the current decline has already lasted longer than any previous one in that period.“When we look at our reconstruction, we can see that the decline that has occurred in the last 50 years or so seems to be unprecedented for the last 1,450 years,” Christian Zdanowicz of the Geological Survey of Canada said Wednesday.“It’s difficult not to come up with the conclusion that greenhouse gases must have something to do with this,” added Mr. Zdanowicz, one of the co-authors of the report in Nature.“We cannot account for this decline by processes that are ‘natural.’”Climate change is thought to be occurring faster in the Arctic than anywhere else on Earth and sea ice is considered one of the main indicators. The ice is crucial in northern ecosystems because it provides habitat for everything from plankton to polar bears.Its gradual disappearance is also opening previously inaccessible areas to the possibility of resource development, as well as to commercial shipping.Mr. Zdanowicz and his team combined 69 different data sources to determine the extent of sea ice for every decade going back about 1,000 years and every 25 years beyond that.The team examined tree rings, ice cores from glaciers and lake and ocean sediments. To check the validity of their approach, scientists compared their calculations for the last couple of centuries with real-world observations from satellites, ship logs and other historical accounts.They found that by the mid-1990s sea ice had fallen even further than in previous lows such as the so-called Medieval Warm Period between 800 and 1300.Team members were also able to conclude that sea ice is influenced by more than just temperature. They discovered that ice actually shrank during what’s known as the Little Ice Age, a period between 1450 and 1850, due to relatively warm ocean waters moving north.That’s what’s happening now, said Mr. Zdanowicz.“In the last 50 years what has really dominated the changes that we see in the Arctic Ocean is the rise in air temperatures and the rise in temperatures of the waters below.”His study didn’t look specifically at the impact of feedback loops in which open water absorbs more of the sun’s heat than reflective ice. But Mr. Zdanowicz said indications are that that is starting to take effect.“If you take this reconstruction and you put it in parallel with a number of studies that have emerged, the indications are pretty strong that the warming of the Arctic is accelerating.”He acknowledged that although he has been able to get more detail on ice fluctuations than ever before, the time span considered in the paper isn’t very long by geologic standards.However, he points out he was involved with a previous paper that went back 10,000 years. That paper found sea ice was lower between 6,000 and 8,000 years ago — and also explained why.“At the time, due to changes in the Earth’s orbit, the northern hemisphere was receiving more solar energy than it does now,” Zdanowicz said.“That process cannot account for what we are observing now. In fact, we should be heading into a gradual cooling trend right now if our climate was strictly controlled by orbital factors.”

    1. RenewableGuy,

      The paper you’re mentioning there is Kinnard et al, “Reconstructed changes in Arctic sea ice over the past 1,450 years”

      There’s a discussion of it at Skeptical Science together with an adaptation of the key graphic from the paper:

      Any suggestion that the Arctic’s recession isn’t linked with AGW is put into stark context by that graph.

  3. This whole ‘story’ was put forth by Steve Goddard.  You’d think Watts would know better by now – Goddard is clueless and never met a conspiracy theory he didn’t like. 

    Prior to 1979 the data was collected in multiple different ways.  Combining those records into a single coherent dataset is not an easy task – but it *has* been done: “Reconstructed changes in Arctic sea ice over the past 1,450 years” Kinnard et al, 2011.

    Robert Grumbine has tried to steer both Watts and Goddard towards a correct understanding of the actual history behind the graphs – see “Tempest in an Icepot” 

  4. We have two options: 1. Deal with the reality. 2. Clutch at straws and bury our heads in the sand, desperately hoping the problem will conveniently go away.

    Here’s a try at #2. I’m not impressed.

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