Arctic melt season changes and the Arctic regime shift

By Javier

In sharp contrast with previous decades, the past 10 years have seen no change in Northern Hemisphere average sea ice extent, according to MASIE (may-zee, Multi-sensor Analyzed Sea Ice Extent) database from the National Sea & Ice Data Center (NSIDC; see figure 1).

Figure 1. MASIE sea-ice extent data for the Northern Hemisphere showing essentially no trend for Arctic sea-ice for the past 11 years.

Based on fundamental climate observations and research it has been proposed by several scientists that the Arctic might have entered a new regime with its most conspicuous consequence a reduction or even inversion of recent Arctic sea ice trends. So far, the data appears to support their interpretation. They are Miles et al. 2014, Wyatt & Curry 2014, and Årthun et al. 2017 (references in the appendix).

Last October I presented some of the evidence at WUWT here.

Despite the complete failure of every Arctic ice-free prediction so far, and the research and evidence that the Arctic is no longer melting as in past decades, some climate alarmists are rabidly attacking this interpretation and those that hold it, including me. See the “Open Mind” post: Extreme Cherry Ice.

MASIE is a relatively new (November 2010) and improved dataset on sea-ice extent for the Northern Hemisphere with very good sea-ice boundary resolution. Sea-ice extent is the preferred measurement by NSIDC to study melting, since surface melting is known to cause sea-ice area measurements to underestimate the sea-ice surface. However, sea-ice extent is rapidly falling out of favor among sea-ice alarmists as an Arctic gauge, replaced by sea-ice volume that has the disadvantage of being modeled, but the advantage that it shows continuous decline, as the models include a temperature factor. Apparently, alarmists believe that Arctic sea-ice is transforming from a pancake into a crepe of the same size.

MASIE starts in 2006. I have determined the start and end dates of the melt season from 2006-2017 (11 complete years; see appendix). The data is presented in table 1.

Table 1. Start day defined as yearly maximum extent day (7-day smoothed). End day defined as yearly minimum extent day. Length is the difference between both in number of days. Extent change is the difference between maximum and minimun sea-ice extent.

The average start for the melt season was on day 68 (March 9 in common years). For the past 12 years there has been a trend towards an earlier start of the melt season, with 2015, and 2016 starting on day 59 (February 28). The trend is very pronounced at –9 days/decade (see figure 2). Stroeve et al. 2014 report a similar trend for 1979-2013 of –2 days/decade. If anything, the trend appears to have accentuated recently. In 2017 the melt season started on day 63 (March 4) as determined by this methodology, right on the trend.

Figure 2. Start of the melt season for the past 12 years showing a pronounced trend towards an earlier start of the melt season.

The average end for the melt season was on day 262 (September 19 in common years). For the past 11 years there has been a trend towards an earlier end of the melt season, with 2016 (leap year) ending on day 253 (September 9). The trend is very pronounced at –11 days/decade (see figure 3). Stroeve et al. 2014 report an opposite trend for 1979-2013 of +3 days/decade. There is a huge inversion of 2 weeks/decade in this trend. According to the trend and methodology, the 2017 melt season is projected to end on day 255 (September 12) ± 1 week.

Figure 3. End of the melt season for the past 11 years showing a pronounced trend towards an earlier end of the melt season.

The observed trends are not sustainable (or the melt period would eventually shift seasons) and probably form part of the observed Arctic regime shift. One possible explanation is that for the past decade winters have become warmer in the Arctic, while summers have become cooler. A good example is this year situation (see figure 4).

Figure 4. Daily mean temperature north of the 80th northern parallel, as a function of the day of year. Source DMI. The average melt season start and end days have been added.

The average melt season length, defined as the number of days from start to end of melt, is 193 days (52.5% of the year, winter is 4 days shorter than summer). For the past 11 years the melt season length has shown a non-significant decrease of –2 days/decade (see figure 5). This contrasts with Stroeve et al. 2014 who report a trend for 1979-2013 of +5 days/decade in melt season length. The evidence does not support the touted increase in melt season length for the past decade. According to the trend, the 2017 melt season is projected to last 192 ± 6 days.

Figure 5. Melt season length for the past 11 years showing no clear trend.

The average extent loss from start to end of the melt season is 10.6 million sq. km. For the past 11 years the extent loss has shown a non-significant increase of 0.65 million sq. km/decade (see figure 6). This trend is dependent on the very low value of the 2006 melt season loss, and shows no increase in surface lost during the melt season from 2007. 2017 started its melt season with a very low value of sea ice extent (14.7 million sq. km), almost as low as 2006 (14.6), and has seen below normal melting so far, so it is likely to end with one of the lowest sea-ice extent losses of the entire series.

Figure 6. Change in extent (sea-ice loss) from start to end day of the melt season for the past 11 years showing no clear trend.

The average sea-ice extent change during the melt season was plotted against the length of the melt season (see figure 7). No significant relation was found as the trend depends fully on two outliers, the very low melting of 2006 and the very high melting of 2012. It is clear that melt season length is not the main determinant of sea-ice extent decrease during the melt season.

Figure 7. Change in extent (sea-ice loss) during the melt season versus the length of the melt season for the past 11 years. No significant correlation is found.

It is important to notice that the analyzed period 2006-2017 includes 7 of the 10 hottest years recorded according to NOAA/NCEI, as reported by Climate Central (see figure 8). 2017 is trending to finish in 2nd-3rd place. The warmest decade in over a century, according to this database, coincides with a decade when no Arctic sea-ice melting has taken place. This demonstrates that global average surface temperatures cannot be the driving force behind Arctic melting, and regional ocean surface temperatures are likely to be more important.

Figure 8. The period analyzed, 2006-2017, includes most of the warmest years ever recorded, and can therefore be considered the warmest decade ever registered. The lack of ice melting demonstrates that global temperatures do not drive Arctic sea-ice melting.

In conclusion, the evidence indicates that for the past 10 years:

1. There has not been any significant Arctic sea-ice melting.

2. Both the melt season start and end have been taking place earlier.

3. The melt season length has not increased.

4. Sea-ice loss during the melt season has not increased.

5. Sea-ice loss during the melt season is not determined by season length or by the average global surface temperature, as claimed by the IPCC.

There is a stark difference between the results from the past 10 years and from earlier decades. This difference suggests a shift in the Arctic ice regime as proposed by Wyatt & Curry 2014 and Miles et al. 2014. The expectation from these authors and from Årthun et al. 2017 is that for the next decade(s) no significant Arctic sea-ice melting should be expected, and a significant increase in Arctic sea-ice is possible.

Appendix.

The MASIE database was downloaded from:

ftp://sidads.colorado.edu/DATASETS/NOAA/G02186/masie_4km_allyears_extent_sqkm.csv

on August 8, 2017.

The Northern Hemisphere data was smoothed with a 7-day centered moving average to reduce daily variability.

Data was plotted with Excel.

Daily polar temperature graph was obtained from the Danish Meteorological Institute at:

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

Bibliography:

Årthun, M., et al. 2017. “Skillful prediction of northern climate provided by the ocean.” Nature Communications, 8, ncomms15875.

https://www.nature.com/articles/ncomms15875

Miles, M.W., et al. 2014. “A signal of persistent Atlantic multidecadal variability in Arctic sea ice.” Geophys. Res. Lett., 41, 463–469.

http://onlinelibrary.wiley.com/doi/10.1002/2013GL058084/full

Stroeve, J.C., et al. 2014. “Changes in Arctic melt season and implications for sea ice loss.” Geophysical Research Letters, 41(4), 1216-1225. http://onlinelibrary.wiley.com/doi/10.1002/2013GL058951/full

Wyatt, M.G., and J.A. Curry. 2014. “Role for Eurasian Arctic shelf sea ice in a secularly varying hemispheric climate signal during the 20th century.” Climate dynamics 42.9-10: 2763-2782. http://cdn.cnsnews.com/documents/Curry,%20Wyatt%20paper.pdf

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301 thoughts on “Arctic melt season changes and the Arctic regime shift

  1. You appear to have ignored the caveat published on the MASIE website “Use the Sea Ice Index when comparing trends in sea ice over time or when consistency is important. Even then, the monthly, not the daily, Sea Ice Index views should be used to look at trends in sea ice.”
    Also in the paper on comparative sources of data https://www.igsoc.org/annals/56/69/a69a694.pdf
    Meier et al. made the following points:

    ” MASIE is not well suited for tracking long-term climate (e.g. trends, anomalies), but is better suited for purposes such as input into synoptic weather models.”
    ” Operational products (i.e. MASIE), while providing more spatial detail and on average higher accuracy in the ice-edge location, are subject to inconsistencies due to data quality and availability.”

    • I used a one week averaged daily value, that takes care of the daily variability problem. And the results and conclusions are the same over a wide range of sea ice extent databases including JAXA and DMI. Last year I didn’t use MASIE and got the same result. As it is said, the results are “robust.” According to sea ice extent the ice is just not melting, and with the same measurement it was melting before.

      • From the above linked pdf:

        However, since MASIE is based on an operational product, estimates may be inconsistent over time due to variations in input data quality and availability. Comparisons indicate that MASIE shows higher Arctic-

        If you get similar results from data which is not declared to be inconsistent over time I would suggest showing it. MASIE is specifically aimed at operational forecasts ie for people needing to know where ice is to avoid hitting it ! It is not intended to be used as you are an there are specific warnings that it is not suitable.

      • Thanks greg.
        This is not the first time some clown has tried to foist off masie analysis here at wuwt.
        The limitations of masie have been explained before.

        A good analyst would compare all datasets.
        A good analyst would read what the data provider cautioned against.

        The fraudulent misuse of open data is one argument those of us who try to free data have a hard time answering. How do we make our data open and prevent frauds like Javier from abusing it?.
        We make the data open to increase understanding not to allow people to misuse that data..that just lures people into weak skeptical arguments, makes all skeptics look bad and wastes the time of good analysts.

      • Mosh,

        If Javier, a PhD in molecular biology, is a clown, what does that make you, an English BA salesman associated with a cooked book GIGO exercise in mendacity?

      • I’ve noticed that Steven Mosher has grown increasingly bitter over the years. Many years ago, I remember that he sometimes had interesting and even insightful things to say. But these days, wherever I come across his name in the blogosphere, his main function appears to be to play the grouch, the snide, the character assassin and the spoiler of comment threads. So most of the time when reading the threads at WUWT I ignore him as a default setting.

      • Thanks Mosher- the article is garbage for the reasons you suggest. Amusing that the WUWT cretins though resort to ad hominem attacks when they can’t back up their claims with science.

        [do you listen to yourself? You call WUWT denizens “cretins” then complain about ad hominem attacks. suggest you comment elsewhere because you clearly don’t understand your own comments – Anthony]

      • While it may be a wrong use of the data-set, it can hardly be “fraudulent” (involving deception). The recommended data-set for the purpose by NSIDC gives the same answer.

        It looks like a full-blown false accusation by Mosher. Nothing out of the ordinary.

      • Bruce August 11, 2017 at 8:47 pm

        Calling real scientists “clowns”, as the salesman Mosh does, isn’t ad hominem?

    • Good that they put the disclaimer there, otherwise climate scientists might inadvertently stumble into some actual science.

      I mean, why risk actually *measuring* sea ice extent, which might show a heretical result, when you can “model” it and get a properly sanctified one?

    • Javier August 11, 2017 at 5:44 am
      I used a one week averaged daily value, that takes care of the daily variability problem.

      But has nothing to do with their point which is inconsistency and MASIE’s unsuitability when comparing trends which is what you are doing.

      • Let’s cut to the chase: Do you, Phil., disagree with Javier’s fundamental conclusions, that average Northern Hemisphere sea ice extent is unchanged for the last decade?

      • Alan Robertson August 11, 2017 at 7:47 am
        Let’s cut to the chase: Do you, Phil., disagree with Javier’s fundamental conclusions, that average Northern Hemisphere sea ice extent is unchanged for the last decade?

        It’s a meaningless statistic since it depends mostly on the winter extent, even a record minimum extent this year wouldn’t change it to a noticeable degree. Hitting zero extent for a couple of days and Javier would still be saying “no change in the Northern Hemisphere average sea ice extent”.

      • “Do you, Phil., disagree with Javier’s fundamental conclusions, that average Northern Hemisphere sea ice extent is unchanged for the last dec”

        It is not possible to draw this conclusion from the MASIE data, because MASIE is described as not suitable for drawing this type of concusion.

        That does not make the conclusion wrong, but it is certainly not demonstrated here.

      • Phil and seaice1,
        Assuming, for the sake of argument that your complaints are valid, can we conclude that there is no basis for you or anyone being concerned about declining ice coverage? Do you have an alternative database that you would recommend Javier analyze?

      • Thanks for replies Phil. and seaice1.
        What data would support, or disprove Javier’s point, if such exists and what conclusion could be drawn from that data?

  2. Climate alarmists and IPCC believe that the thermal response to increasing CO2 is a feedback gain from increasing water vapor that results from higher temperatures, leading to much higher temperatures. Current climate model averages indicate a temperature rise of 4.7 C by 2100 if nothing is done, 4.65 C if U.S keeps all its Paris commitments and 4.53 C if all countries keep their part of the agreement. In all cases, with or without Paris agreement we are headed for a disaster of biblical proportions.

    As the chart indicates, implementing all of the Paris agreement will delay the end of mankind as we know it by at most 4 years.

    Myself and quite a few scientists, meteorologists, but mostly engineers believe the feedback loop in nature is far more complicated than that, in fact, there is a large negative feedback in the system, preventing a temperature runaway, and we have the observations to prove it. The negative feedback manifests itself in 2 ways:

    Inorganic feedback, represented by clouds. If there were no clouds, the tropics would average a temperature of 140 F thanks to the greenhouse effect. The clouds reflect back up to 300 W/m2 into space rather than the same energy being absorbed into water or soil. Clouds are highly temperature dependent, especially cumulus and cumulonimbus clouds. Cumulus clouds are formed in the morning, earlier the warmer it is, and not at all if it is cold, thunderstorms appear when it is warm enough. The feedback, which was positive at low temperatures becomes negative at warmer temperatures, and in the equatorial doldrums, surface temperature has found its equilibrium. No amount of CO2 will change that. Equatorial temperature follows the temperature of the ocean, warmer when there is an el niño, cooler when there is a la niña. Here is a chart of temperature increases since satellite measurements began as a function of latitude.

    The tropics follow the ocean temperature closely, no long term rising trend, the extratropics are also stable.

    Not so at the poles. the temperature record indicate a noticeable warming with large spikes up and down, up to 3 degree Celsius difference from year to year, especially the Arctic. So, how much has the Arctic melted? Here is a chart of Arctic ice cover for 31 May for the last 39 years.

    If this trend continues, all ice may melt in 300 to 400 years, faster if there is further warming and nothing else is changing. Let’s take a look at the Arctic above the 80th latitude, an area of about 3,85 million square kilometers, less than 1% of the earth’s surface, but it is there where global warming is most pronounced. Here are two charts from the last 2 years, ending with Aug 10 2017.

    Starting at summer 2016, the Arctic was melting quite normally, but something else happened that is not shown in the chart. Every 5 years or so, the Arctic suffer a large storm with full hurricane strength during the summer. In 2016 there was no one, but two such storms, and as they happened late in the season when the ice is rotten they result in a large ice loss, making the ice minimum the lowest on record, and the ice volume nearly 4,000 Gigatons (Gt) less than the 30 year normal. Then the temperature from October thru April did run 7 degree Celsius warmer than normal with a spike as high as 20 degrees warmer. Yet today the deficit is down to 2,500 Gt. What happened? It snowed more than normal. In the Arctic, it gets warmer under clouds, warmer still when it snows. Take a look at Greenland and what has happened this freezing season. It has snowed and snowed and Greenland has accumulated 150 Gt more ice than normal. So, at this point in the season we are a total of 1650 Gt ahead of last year, and this is with Arctic temperatures being seven degrees warmer than normal during the cold season. The counterintuitive conclusion is that it may very well be that warmer temperatures produces accumulation of snow and ice, colder temperatures with less snow accumulates less. What happens during the short Arctic summer? With more snow accumulated it takes longer to melt last years snow, so the temperature stays colder longer. If this melting period ends without melting all snow, multi year ice will accumulate, and if it continues unabated, a new ice age will start.

    The second feedback loop is organic. More CO2 means more plant growth. According to NASA there has been a significant greening of the earth, more than 10% since satellite measurements begun. This results in a cooling effect everywhere, except in areas that used to be treeless where they have a warming effect. The net effect is that we can now feed 2 billion more people than before without using more fertilizer. Check this picture from NASA, (now they can publish real science again) showing the increased leaf area extends nearly everywhere.

    In addition, more leafs changes the water cycle, increases evapotranspiration, and more trees and vegetation reduces erosion and unwanted runoff. Good news all around.

    In short, taking into account the negative feedback occurring the earth will warm up less than 0.5 degrees from now, not at all in the tropics, and less than 3 degrees at the poles.

    https://lenbilen.com/2017/06/04/with-the-paris-accord-not-signed-can-the-world-still-be-saved-a-look-at-the-arctic/

      • and 39 years into what we could therefore consider the next cycle, it is lower than at any point in the 1940s low and still declining

      • Griff,
        You said, “…and still declining.” I didn’t get that from Javier’s analysis. Your source, please.

      • So you’re saying there are cycles in play here, Griff? Please describe them for us. It will save tens of millions of dollars in unnecessary research costs.

      • Griff,

        You missed the whole point of this post.

        Arctic sea ice is not still declining. It has flatlined for ten years, with the record low five years ago.

        This, despite record warm years and steadily rising CO2.

        Your hypothesis of man-made sea ice decline is yet again shown false.

      • Griff,

        On the basis of satellite observations so far, the period of decline was 1979-2012. No year since 2012 has been close to that low.

        So, unless and until there is a new record low, such as you predicted was a sure thing for this year, the interval of declining ice was 1979-2012, ie 34 years inclusive.

  3. >>The lack of ice melting demonstrates that global
    >>temperatures do not drive Arctic sea-ice melting.

    So perhaps polar ice extent is albedo regulated, and thus possibly caused by industrial dust and soot. As was true of the great ice ages and interglacials over the last million years.

    Is CERES indicating any changes in polar albedo?

    Ralph

      • There was no lack of AMO and ENSO warm phase either. Cycles and waves can be so mean that way, until their slope changes again.

      • Griff! There is certainly a sufficient lack of melting to destroy your prediction that ALL the ice would be gone by now! How much lack of melting do you want?
        P.S.- If freezing counts as a lack of melting then hold onto your hat cuz here it comes!

      • John, the trend is down, with yearly variation.

        The extrapolation from the volume figures gives seasonally ice free in the 2030s

        There is less ice now than in the 1940s… the drop in volume and low extent in the last 40 years ahs been truly vast

      • He’s talking about the last 10 years friend. Your charts proves that over the last 10 years here has been a hiatus. You need to reevaluate your chart.

      • and extrapolate July out for 100 years and we have NEGATIVE millions of square miles of sea ice. The physical properties of the universe will go through the rabbit hole and we will all implode.

        At least your great great grandchildren will have a new field of science to study …. NEGATIVE SEA ICE.

      • It seems to get lost of that crowd that you need to be careful taking linear extrapolation to far. Griff had Arctic Ice free by this year remember because the wiggly line had gone into uncharted position or some rubbish. I don’t think anyone will argue it hasn’t lost some ice since the 1980’s but the idea of extrapolating that down to zero is just as stupid as Griff’s ideas. It seems to be a climate science meme extrapolate out to infinity no matter how stupid the answer.

      • “I don’t see the hiatus.”

        Well if you guide the eye by fitting a irrelevant straight line to everything your will conclude that everything is a straight line. That is an obvious result of what you are inputting onto the data instead of looking at the data as it stands.

        If you look at your July graph you will find that nothing has changed much in ten years. It was a little lower in 2012 and little higher now. This is the same as what is shown by the annual minimum, which used to be the go-to OMG statistic.

        2016 min was the same as 2007 in. That is pretty “hiatus” looking. Certainly not “run away” melting or anything that can be described as a tipping point.

    • Monthly charts won’t tell you the story, as they are very dependent on Arctic weather. The initial extent and the end extent are what matters, not the actual path from one to the other. Months with a lot of melting are followed by months with little melting.

      • The extent loss per saison from another extent record ( Jaxa):

        It includes data from 2003…2016, a little bit longer than MASIE and without the limitations mentioned by Phil. It seems that in 2007 there was a shift from a loss of about 9.2 Mio km² ( 2003…2006) to about 10 Mio km² thereafter with one outlier: 2012.

      • ” If you have to do statistics, you should have done a better experiment ”

        Stolen brazenly from Ernest Lord Rutherford; a famous Kiwi Physicist; excuse me that is Nobel Prize winning Physicist. Dunno if his prize was the Physics prize or the Chemistry prize.
        Seems to me at Electrons do Chemistry, and nucleons do Physics.

        G

        PS it would seem that Pres, Donald Trump has given us a new word for “Temperature Anomalies” and “Global Average Temperature .”

        ……… FAKE NEWS ……

        Both describe things that were never actually measured by anyone, anywhere, at any time ! Just think; Anomalies are differences from a fake baseline, and are use to create a new fake baseline, that people are led to believe is real.

    • The article concerns the last 10 years and you post two graphs covering 36 years. Why don’t you be a sport and post a graph covering the last 100 years and see where we are?

      • “Look from 2006 on and you can’t miss it!”

        Oh. I get it. You need to cherry pick your start date. I should have known.
        Now that I think of it, didn’t Tamino deal with this a few ago?

      • The guy who cherry picks his start date is whining that someone has cherry picked a different start date.

      • “the past 10 years have seen no change in Northern Hemisphere average sea ice extent”

        That’s not cherry picking…..

      • REALLY S, I should add that I salute you for at least coming here. You will admit that you can learn some things here. Also, you will note that your free to disagree and make your points as you see fit with the only restraints being on decency and over the top name calling – even so they aren’t rigid on the rules and political correctness is not at all a constraint.

        This site stands out as a place where you will never be censored for your views or ‘take’ on a subject, but be prepared to back up your views among this herd of cats. Try disagreeing with Tamino’s “open mind” or Sceptical Science. At the latter, they even alter their posts afterwards and get rid of comments that don’t fit the redone post!

        Finally a word to the wise on your name. Like a ‘tell’ in poker, it protesteth too much. Think Deuche Demokratische Republik, or the Democratic People’s Republic of Korea, or Sceptical Science, or Tamino’s Open Mind- one of the most censored sites on the net. You will get to like having your say and accept that it’s good to be engaged by other minds here.

    • 1979 marked the highest ice levels in the last century. The ice levels have dropped since then is neither surprising nor alarming.
      Similarly, the fact that the world has warmed up since the end of the little ice age is neither surprising nor alarming.

      • MarkW – can you provide erefence for your assertion? There are studies that contradict you, for example@

        This guest article is based on the following journal paper: Walsh, J. E., Fetterer, F., Stewart, J. S. and Chapman, W. L. (2016) A database for depicting Arctic sea ice variations back to 1850. Geographical Review, doi:10.1111/j.1931-0846.2016.12195.

    • Great RECOVERY from the extremes of 1970’s isn’t it. !

      Level is still above what it has been for some 90-95% of the last 10,000 years.

      Trouble is, reallygullible, that the recovery has stopped, and the AMO is turning.

      The benefits of a continued loss to the people living up there of a continued decrease towards the lesser extent of before the LIA would be very significant. Wouldn’t you agree.

      Look at all the efforts spent on ice breakers etc in an attempt to get just a few weeks of actual commerce and travel and fishing etc.

    • Late 1970’s was up there with the extent of the LIA.

      Be very happy for the small amount of warming we have had since then.. or move to Siberia (but you won’t will you reallygullible, you like your inner-city warmth and your fossil fuel heating in winter.)

    • Some exelent points from others. The biggest issue with your post is that the article is discussing 2006 to 2016(2017), whereas you are displaying the 1978-2016 data, and drawing a straight line through it. Kind of hard to show a deflection in the last quarter of a graph when you use a straight line.

      Also, at no point did you inform us of the source of your numbers/graph.

      • Mosh

        And you are the great arm chair QB, how about once you step up and tell us what is going to happen and not just what everyone else doesn’t understand about everything.

      • Rather: ‘Is deceleration imminent?’

        For me, the trendline is actually far too good to be true. Why so? Well, they wouldn’t post it if it wasn’t adjusted.

      • Steven Mosher August 11, 2017 at 1:51 pm

        Javier cites all his sources.

        What are you talking about?

    • 1979 is a cherry-picked date to make it look like there is unprecedented melting in the arctic, but if you go back just a few more years you can see that 1979 is a highpoint for ice, but the ice has been thinner in the past than it is today, so today’s situation is not unprecedented in the least.

    • Since the Arctic is where heat goes on its way to space, why wouldn’t it be the last place to show the hiatus? Moreover, if you are saying that the Arctic is still showing warming and we have an hiatus on a global basis, then the rest of the planet must be cooling already!
      The natural question that derives from that fact is this:
      If the Arctic gets its heat from the tropics, and the tropics are cooling, where will the heat come from to maintain anomalously low ice levels in the Arctic? See how that works when you use logic instead of garbage computer models?
      Hint: sea ice has stabilized and will soon start the growth phase of its cycle.

    • Hey, there’s still a month to go! A couple more CO2 molecules would probably do it. We’d better all hold our breath! Griff, that means you!

    • ‘may well be’ does not = ‘will’

      and if you look at serious discussion of this year’s melt season, with a cold central arctic and storms, then you’ll see many are of the opinion if the weather conditions had been more like 2012, we’d be at a new low well beyond 2012. With amazingly broken up thin ice and storms over the arctic, still a surprise end to the season possible.

      The ‘ice free’ arctic and new lows on the path to that unfortunate event are definitely coming.

  4. I followed your link to Tamino’s Open Mind:

    https://tamino.wordpress.com/2016/10/18/extreme-cherry-ice/

    I noted that of the nine comments that appear in that October 2016 post none of them are yours.

    Let me guess, you are banned from posting at Open Mind. Tamino whoever he is, Grant Foster I’m told, banned me when I attempted to defend a graph that I had posted here at WattsUpWithThat
    https://tamino.wordpress.com/2016/09/20/misleading-trends-sea-level-version/
    that he took issue with. No notice, no nothing, my comments just don’t appear.

    He apparently isn’t a very decent fellow.

    • Yes, I tried to comment on several occasions even before that article and he never accepted any. Only one belief is accepted at the Church of the Global Warming.

    • Grant Foster is a coward who will not discuss anything in a context where he does not have total editorial control, where he can and will remove anything that challenges or contradicts what he says.

      As such he has no scientific metric.

      Open Mind ? What a joke.

    • my posts have been vanishing -will probably show up later.

      I’m sure others have seen this bermuda triangle which sometimes affects this website!

      • Griff, I am with you on this one. I have had several posts not appear in the last week or so. The symptom is that after clicking on “post comment” all appears to be well. Then the page reloads and the comment is simply not there. It does not go into moderation (which is displayed to me). It simply does not appear.

        It happens on some articles but not others.

      • I have had this issue as well. I am most certainly not of the AGW persuasion so there is no discriminatory editing. Why are so many Warmist sites practising that type of editing, Griff? We enjoy (too strong a word) your lunacy here.

    • Could be that the Donald’s curtailment of funding climate change has resulted in Griff’s monthly cheque failing to appear.

    • John, they set the rules how they see them…

      The UK Guardian newspaper sets the bar too low, in my opinion – ‘climate change is a fact, therefore a post contradictory to fact gets removed’

  5. Javier, there are a few different data sets out there.
    Many of them contradicting each other on a daily basis.
    2017 is currently lowest in one second lowest in others and 5th lowest in others.
    Who to believe?
    Of greatest interest was the widespread belief with the warm arctic winter and low top level that this year would precede to be the lowest September extent on record.
    Which is looking far less likely in the last 2 months.
    Indeed the number of people commentating on warmest sites has dried up quicker than the ice extent loss has stalled.
    Still too early to know.
    Several people predicted a slow thaw based on increased NH snow. Ron Clutz did something on the Barent’s Sea. Even Jim Petit put in a prediction that the ice loss would be low.
    Maisie has a section that gives the loss in the different seas making up and surrounding the arctic basin.
    Perhaps you could comment on that and how CAB and Greenland Sea retention has, to date only, stalled some of the loss.

    • Who to believe?

      It is hard to say who is getting the best results. One would think that with high precision instruments measurements would be more consistent, but differences between temperature databases already show that not to be the case. The important think is that they all agree on the basic behavior and trend.

      I really don’t follow or have analyzed the sea ice situation by seas and areas, so I can’t comment much on that. It is quite amusing how people (including me) get so interested by things that don’t affect them personally as to follow them in minutia detail. Very like what happens to some sport fans that follow their favorite sport, team and players reading everything that is published every day. However the entertainment value of melting ice is still unrecognized by most.

      • However the entertainment value of melting ice is still unrecognized by most.
        Curling just isn’t popular enough.

    • Except it doesn’t, because the extent and volume in 2017 are currently about the same as 2007 and only a little above 2012 – in other words among the 3 lowest records in the satellite era.

      • It can be anywhere from 3 to about 10th depending where you cherry pick the point on the graph. However there isn’t supposed to be any is there Griff you had it all gone because it was unprecedented. Only now it’s not so unprecedented is it.

      • About the same as 2007. In other words no melting in 10 years. Just as the article stated.
        Time to call of the panic.

      • Griff,

        As you were told when you predicted a record low this year, you were almost sure to be wrong, unless there were two August or September cyclones again, as in 2012.

        In NSIDC “data”, Arctic sea ice extent is currently higher than in 2012 and 2007, tied with 2011 and on track to cross over 2016. Who knows what will happen in the next month, but your wish is probably not going to come true.

        Your comment makes Javier’s point for him. For the past decade, Arctic sea ice extent has flatlined. The low year, by a big margin, remains 2012.

      • Present Arctic sea ice minimum extent is largely a function of wind disturbance and higher winter temperatures as a result of more open water maintaining basically a marine climate. As such, open water in the Arctic is self sustaining. When an extended period of reduced wind or temperatures allows the sea ice to expand beyond a certain (unknown) amount, the sea surface is less disturbed as the ice “protects” the sea from the wind.
        In this other stable mode, sea ice expands and the marine characteristics of the weather give way to the colder weather system. This mode also separates the sea water from the air and thereby reduces the heat loss. The result of this is a slowly rising water temperature until the ice becomes too thin to hold together. When it breaks up, the wind driven, constant disruption mode restarts along with an increase in heat rejection. So heat rejection in the Arctic has a multi decade, cyclical aspect that we are in the middle of.
        When you use a little analytical thought and common sense without any preconceived idea of what the outcome should be it’s surprising what you come up with. It is the death of ju-ju. CO2 or otherwise.

      • The freak Greenland surface ice melt brief event in summer 2012 also had alarmists predicting the end of the GIS by 2016. That was a once in 123 years event.

      • Hey Griff, Tony Mcleods done here in about three weeks because of his bet with me, wanted make it 2 frauds gone? Give me a date when you say the North Pole will be ice free and I’ll bet you that it won’t happen the loser never posts on WUWT again. Come on you creep step and back your BS.

  6. Javier, you didn’t mention the effect of El Nino on 2015-16 which makes your observations even more conservative in terms of little melt. That the ocean has overall been cooler, despite the El Nino which, although high, was not supported by a large volume of warm water.

    The precipitous drop in ENSO after the warm peak reflects this and the fact that the warm ‘blobs’ in both hemispheres had turned to large cold Blobs. Moreover, instead of the usual upwelling of cold water in the eastern Pacific to initiate La Nina, the ENSO region was cooled by water slanting westward and equatorward into the region from the cold Blobs in both hemispheres. We are now in La Nina territory which is also getting help from the abundance of other cold water in the blobs which has a stronger cooling of the atmosphere than just from the ENSO.

    There has been a cool summer in much of the NH Temperate zone and a colder winter in the SH. Heavy snow fell in Iceland, the Alps and Argentina this July and August. My prediction is for a very cold NH winter. I’ve been discussing this changed scenario here before the El Nino peaked.

    • As per my post above and in continuance, I believe that we are witnessing a multi-decadal heat rejection cycle in the Arctic. I expect that means that the warming we experienced from approximately 1980 to 2000 is a result of the open water in the Arctic, not the cause of it. This heat rejection phase was almost complete 18 years ago and Arctic ice loss began to slow until it stopped by 2007. The open water there is pretty much self sustaining due to wind and marine temperature effect but the water temps will still slowly drop until widespread freeze over begins to reduce wind disturbance, at which point the expansion and thickening of sea ice becomes self propagating. I suppose someone could model this if they cared about reality instead of their political project.

  7. Excerpted from above commentary by Javier:

    The average end for the melt season was on day 262 (September 19 in common years).

    Oh my, my, …… just luck maybe …… that it almost coincides with the Autumnal equinox on the 23rd?

  8. Figure 8. The period analyzed, 2006-2017, includes most of the warmest years ever recorded, and can therefore be considered the warmest decade ever registered. The lack of ice melting demonstrates that global temperatures do not drive Arctic sea-ice melting.

    Assuming that temperature records are reliable. Big Assumption.

  9. Everybody forgets that in 2012 there was a very strong wind and therefore the satellite measured a larger loss of ice extent. The ice was broken in pieces and the satellite did not reckonise it. It does not change the conclusion, but it is worth to mention.

    • Even though the past five years, 2012-16, incl, contain the anomalously low record year of 2012 and the super El Nino years of 2015 and 2016, its average Sept minimum (~4.4 million sq km) is scarcely lower than for the previous five years, 2007-11 (~4.5 million sq km).

    • And you don’t ask yourself how come in 2012 the ice is thin enough to be broken and scattered like that?

      you aren’t claiming the 2012 wind as unique?

  10. Javier

    I have written two very detailed articles on arctic sea ice melt. The first from 1815 or earlier which lasted intermittently for Some 30 Years and the other the 1920 to 1940 period.

    Both times the whalers and scientists talked about the warm winters and in particular the warm currents. In the case of the 1920’s warming the Antarctic also retreated substantially

    Tonyb

  11. “Winds from Siberia reduce Arctic sea ice cover, Norwegian researchers find

    Summary:
    The ice cover in the Arctic has decreased dramatically in recent years. Norwegian researchers have discovered that changes in air circulation patterns create winds that push away the ice. The changed wind direction pushes large ice masses away from the Arctic and down along the eastern coast of Greenland. At the same time, less ice forms when the winds over the Arctic are determined by the pressure systems in northern Russia rather than those over the North Atlantic and the Pacific Ocean, as is normally the case”

    https://www.sciencedaily.com/releases/2010/04/100427111449.htm

  12. What people really ought to realise is that current Arctic sea ice levels are only a tiny amount down from the most extreme levels in 10,000 years.

    And as shown above, the 1970’s were up there with those LIA extremes.

    All this “anguish” and “panic” from the alarmista, is because of a natural recovery from those extreme levels.

    Its really quite silly, childish, and reminiscent of the chicken-little story, once put into a longer term perspective.

    • but 10,000 years ago there was a profound melting driver on the arctic ice which is not in play today – the stage of the Milankovitch cycle then meant that the summer ice received vastly more insolation due to orbital inclination.

      you can’t compare 10,000 years ago with now.

      https://www.the-cryosphere.net/8/1419/2014/tc-8-1419-2014.pdf

      “We find that during peak Eemian conditions, increased insolation contributes 20–50 % to the surface melt anomaly. “

      • Yes I had not realized they had Polar Bear bones dating back 110,000 years and they managed to survive all the changes in Arctic Ice in that time. That sort of got ignored because it didn’t follow the narrative.

      • Griff,

        You need not go back to the Holocene Climate Optimum, ie 5000 years ago, not 10,000, to find lower sea ice than now. The Minoan Warm Period 3000 years ago, the Roman Warm Period 2000 years ago, the Medieval Warm Period 1000 years ago and even the 1920s-40s had lower Arctic sea ice extent than now.

        Nothing the least bit out of the norm is happening there now. Clearly CO2 has nothing whatsoever to do with it, since Antarctic ice grew during the 1979-14 interval, despite steadily rising CO2 levels.

        The year 1979 had the highest Arctic sea ice of the past century. Its decline since then is entirely natural. There is no evidence supporting a man-made component, except maybe soot. Or, alternatively, cleaner air.

      • DENIAL of Arctic history is the only thing that keeps your mindless prattle going.

        Eemian ?? WTF?? That was 120,000 year ago, bonehead. !

      • Ha! Priceless! In every Griff containing thread, there comes a point where someone utterly destroys him. Then he goes away for a few days. AndyG-you are today’s winner! Congratulations and thank you!

    • I must say I don’t care for those time-reversed x-axis charts.
      Time is supposed to run left-to-right. Sorry, it just is.

  13. Loss of arctic sea ice is a net negative feedback. It allows the relatively warm ocean to lose ~300 watts which is far more than the loss of albedo allows to be absorbed (water at low angles of incidence is quite reflective and the summers are quite cloudy).

  14. This isn’t sea ice, but it is significant – this season’s Greenland ice-sheet-surface-mass :

    “Top: The total daily contribution to the surface mass balance from the entire ice sheet (blue line, Gt/day). Bottom: The accumulated surface mass balance from September 1st to now (blue line, Gt) and the season 2011-12 (red) which had very high summer melt in Greenland. For comparison, the mean curve from the period 1981-2010 is shown (dark grey). The same calendar day in each of the 30 years (in the period 1981-2010) will have its own value. These differences from year to year are illustrated by the light grey band. For each calendar day, however, the lowest and highest values of the 30 years have been left out”

    Graphics shown at this link:
    http://www.dmi.dk/en/groenland/maalinger/greenland-ice-sheet-surface-mass-budget/

  15. From the OP:
    2017 started its melt season with a very low value of sea ice extent (14.7 million sq. km), almost as low as 2006 (14.6), and has seen below normal melting so far, so it is likely to end with one of the lowest sea-ice extent losses of the entire series.

    Based on NSIDC Chartic 2017 maxed at 14.42 a bit lower than 2006 (14.68) but not much different. However 2006 had a minimum of 5.774 on the 17th Sept whereas 2017 is already at 5.893 so will probably be below the 2006 minimum in a couple of days with about a month of the melting season to go. Even a low loss of 10 million sq km would give a minimum of 4.42, your linear fit would suggest a loss of ~11 and a minimum of 3.42. So that would imply a minimum between last year and 2007 and slightly lower than the all time record (2012).

    • Again, it needs to be stressed that tis is an entirely natural drop from levels in the late 1970’s that were similar to those during the LIA.

      Its is a RECOVERY to more normal levels.

      But with the AMO turning, and the sun having a snooze, I suspect we will see the extent to start to climb again over the next few years. A pity really, because the people up there could have used some respite from the freezing blockade of sea ice.

  16. The annual CAGW sea-ice publicity stunt is about to get underway, sailing from Alaska to the North Pole:

    http://www.npr.org/2017/08/10/542547005/sailing-to-the-north-pole-thanks-to-global-warming

    … or is it? So much doom-laden publicity has already been generated, much of it broadcast by the BBC, that they hardly need to bother leaving port. I don’t suppose that they intend to use the entire window of gaps in the ice to sail to somewhere near the Pole, get the eagerly desired publicity photo of a sailing ship there, then get stuck in order to prolong the publicity? Does Planet-Saving zealotry extend that far?

    Scroll down in the following link to see the current ice extent near Alaska:

    https://www.weather.gov/afc/ice

      • @climanrecon – from your NPR link:

        “A crew plans to leave Nome, Alaska Thursday (Aug, 10th) and sail to the North Pole. The voyage may now be possible due to sea ice melt in the Arctic caused by climate change.”

        It looks like they are in for some rough sailing through all that ice up to and including the North Pole…

      • One can only hope that they don’t get farther than the ice edge. If they try to go further north by following leads and fissures in the ice their yacht will most likely be crushed as soon as there is strong wind. I’ve seen what ice press can do.

      • You should match that with a concentration chart, showing that the above is a coloured in outline…

        Look at this:

        Looks a bit different, eh?

    • For all their despair over loss of sea ice, I’m betting they made sure that a U.S. or Canadian ice breaker is available on short notice.

    • Or this one, since a lot of ice seems to have sort of gotten lost in Griff’s map:

      Note that while the scale in Griffs version goes to zero, there oddly enough doesn’t seem to be any areas anywhere with less than about 25% ice, while the Norwegians have a lot of those.

  17. Thanks Javier.

    Area vs volume. Volume is useful for a trend, nothing more, area measurements have several uses.

    Area ignores storm compacted ice events. Volume(somewhat accurate) would address that. Yes volume has a nice declining trend, but no biggy, a warming world cant do anything else.

    The question as always is.. still, what causes the warming. They always try move on as if that question has been answered already.

  18. Question. What is the total storm induced loss of sea ice area over the past 48 years in Antarctica and the arctic? :D

    If you cant answer that then area trends are pretty meaningless, Antarctic and arctic storms played a significant role in bringing ice trends down

  19. From the article: “It is important to notice that the analyzed period 2006-2017 includes 7 of the 10 hottest years recorded according to NOAA/NCEI, as reported by Climate Central (see figure 8).”

    No, the NOAA/NCEI data has been bastardized and specifically formulated to make it appear that each succeeding year is hotter than the last. But when you look at an accurate chart (satellite) of the Earth’s temperatures you will see that all the years between 1998 and 2015 were cooler than 1998, and 2016 was only one-tenth of a degree hotter than 1998, so claiming the period contains seven out of 10 “hottest” years, is a lie. And keep in mind that the 1930’s was hotter than 1998 and 2016, so the last few years are also-rans at best.

    Here’s a real unbastardized chart to put the lie to the NOAA/NCEI lies:

  20. The lower rate of melting of arctic sea ice is occurring at the same time as we are having a lack of sunspot activity it maybe something that is happening like the contraction of the thermosphere.

  21. also, when storms do break up ice sheets and compact them, sunlight goes straight into the surface waters which would otherwise be covered in sea ice, that happened last winter and the floes were large in late june. Ice breakers have been flat out, not even one to spare for a 17 million research jaunt

    • Mark,
      A minor quibble: You said, “…sunlight goes straight into the surface waters…” Strictly speaking, that can only happen between the Tropics of Cancer and Capricorn for short periods of time. Most of the time that sunlight reaches the surface in the Arctic, the rays are far from perpendicular and the water has high reflectivity that can get as high as for snow.

    • Even at the height of summer, because of the low angle of the sun, the difference in the amount of light reflected from ice vs. water is hard to measure.
      As the sun gets closer to the horizon, the difference becomes smaller.
      The only difference less ice makes is that it’s easier for the water to lose heat to the atmosphere.

      • tty August 12, 2017 at 5:30 am
        Not a lot of sunlight in the Arctic in winter. Not in Helsinki either as a matter of fact. But it is true that there was a huge growth in ice late in the last winter season:

        Indeed there was because according to that graph there was no growth until January, whereas in the average year there would have been 400,000 km^2 of growth. In the next few months growth resumed and the coverage returned to average, what that does mean though is that the ice that did form would be thinner than in a normal year.

    • Not a lot of sunlight in the Arctic in winter. Not in Helsinki either as a matter of fact. But it is true that there was a huge growth in ice late in the last winter season:

  22. Thanks Javier for this important update on Arctic ice.
    Both sides in the climate debate have been quiet on the subject recently. The warmists are disappointed at the death spiral of their death spiral. The ice won’t go away. And the skeptics having been burned by previous predictions of recovery are staying off the subject.

    But Javier is right – the stasis of the ice in the last decade is an important story in its own right. It does indeed place a real question mark over the claims of warmest evah atmospheric temperatures. However oceanic processes arw slow and take a long time to turn around.

    Arctic ice is a solid tangible index of climate status, unlike temperature measurements with their intractable problem of human contamination.

  23. Nobody seems to have posted this chart. It shows quite clearly that sea ice extent for the decade has been constrained to a very narrow band:

    • From your link I find this an interesting quote:

      “There’s far less ice cover on the Arctic in general in the summer months, but that doesn’t mean there’s zero — and it can turn up in different places.”

      It seems to me that from that quote the uninformed would have no idea that the ice cover in the summer months is still generally around 4 MILLION square miles which is more than four times larger than Greenland and around the same as Europe and close to 7% of the Earths total land area.
      And that’s at summer minimum!

      I suppose that doesn’t make the minimum sound scary enough :)

      • Oh well, I wasn’t paying attention, km2 not miles, but still apparently good enough for climate science based on what Chris Mooney said :)

        Around 4 Million km2 is hardly something to sniff at!!

      • tobyglyn August 11, 2017 at 10:47 pm
        It seems to me that from that quote the uninformed would have no idea that the ice cover in the summer months is still generally around 4 MILLION square miles

        Compared with the average during the 80’s of ~7 million km^2 or the average during the 2000’s of ~5.5.

        https://ads.nipr.ac.jp/vishop/#/extent

  24. If you want to draw any conclusions about Arctic sea ice trends, keep a couple of things in mind :
    1. The satellite data begins in 1979, which happens to coincide with the end of the 1950 to 1978 cool period when sea was presumable at its maximum.
    2. Decline in sea ice from 1979 to 2000 is not surprising since it coincides with the 1979 to 2000 warming.
    3. Comparing extent of sea ice now (at the end of a warm period) with sea ice extent in 1979 at the end of a cool period) makes no sense at all. What should be compared is extent of sea ice now with the extent of sea ice at the end of the 1915 to 1950 warm period. Unfortunately, we don’t have good data for the earlier time period. We would also like to compare the sea ice extent in 1979 at the end of the 1950 cool period with the extent in 1915, the end of the 1880 to 1915 cool period. But again, we don’t have the data.

    Until we can make these kinds of comparisons, conclusions about trends since 1979 don’t mean much.

    • Actually I think it would probably be possible to get fairly good data for at least the 1930-1950 period. There is quite a lot of Norwegian, Danish and Icelandic data for the North Atlantic sector, and a fair amount of Russian data for the Siberian sector from 1933 on (when regular traffic through the North-East passage started).

      The difficult area is Canada, but the data almost certainly exists in RCMP and Hudson Bay Company archives if somebody could be bothered to look for it. For example in 1937 the HBC vessel Aklavik sailed from Cambridge Bay around King William Land, up the Peel Channel and through Bellot Strait into Prince Regent Inlet and then returned the same way to her home base in Cambridge Bay. Since this is the only really difficult part of the Nortwest Passage this means that in practical terms she passed through the passage both ways.

      In the same way the partial gap 1940-45 in North Atlantic datasets could certainly be filled in from military archives.

      • DOE

        Trouble is , that while 1955 was obviously much lower than the large increase that followed at the end of the 1970’s, it is unsure exactly what was being measured in this graph

        You could tack the early satellite data on like this…

        … but I’m not sure we can actually do that, because I suspect they are measuring different things. The DOE graph states “Arctic Ocean” (what is that?) while satellite data is for “Northern Hemisphere”

      • Actually there is very good Russian, Danish, US, Canadian, Royal Navy, US Navy (including subs under the ice), Alaskan, whaling fleet data right through into the 19th century.

        see my post below to a link to this research

    • Don Easterbrook August 11, 2017 at 11:53 am

      3. Comparing extent of sea ice now (at the end of a warm period) with sea ice extent in 1979 at the end of a cool period) makes no sense at all.

      This statement is based on your unfounded assumption that we are at the end of a warm period

    • Arctic Sea Ice reconstruction (Connolly, connolly and Soon, 2017)
      Don, Connolly, Connolly and Soon have a reconstruction of Arctic Sea Ice extent in their new paper in Hydrological Sciences Journal. The low point before 1979 was 1943. 1979 was fairly high by 20th century standards.

  25. This article is excellent and informative, but If you’re trying to send a message, be sure to select the endpoints of your trendline with your message in mind. Anything is possible in a world governed by cycles. Let the reader beware.

  26. There is extensive evidence that a north west passage has existed about 1000 years ago, if you track the movements and settlements of the Vikings. 5 centuries later people in Holland heard these Nordic stories of the existence of this passage and tried to establish if it existed.
    Sadly the expedition of Willem Barentz ended in disaster.
    If Javier is right, this time around there never will be a north west passage….?

    • Larsen passed through the NWP in 1944 in the wooden St Roch, and the SS Manhattan (oil tanker) followed roughly the same route in 1969.

      That route is currently rather blocked.

      • “Painting Depicting the Meeting in the Northwest Passage of the RMS Nascopie and the HBC Aklavik by the Artist Thomas Harold Beament”

        “There is a wonderful painting in the art collection of the Maritime Museum of British Columbia which depicts the historic meeting of the HBC schooner Aklavik with the RMS Nascopie at Fort Ross, Northwest Territories. In 1937 the Nascopie sailed from the Eastern Arctic to Prince Regent Inlet and into the Bellot Strait to allow the Hudson’s Bay Company to establish Fort Ross. While there she was met by the HBC schooner Aklavik which had sailed into Bellot Strait from the Western Arctic.”

        http://www.nauticapedia.ca/Gallery/Aklavik_Nascopie_Painting.php

      • Richard,

        Any idea of the route followed by these two vessls?

        The brief history I can find seems to indicate the southern route through Bellot Strait and Cambridge Bay.

      • but it has been open every year for about the last decade, to all types of vessel without icebreaker assistance….

        something markedly different from 20th century multi year, multi ice breaker passages on widely separated occasions…

        and will very likely open again by September.

      • Yes, the RECOVERY from the extremes of the late 1970’s is a MASSIVE BENEFIT, isn’t it griff

        Maybe they won’t need ice-breakers at some point in the distant future, and other countries won’t have to rely on Russia for safe passage.

      • Griffie, it was the small vessel in the picture that did the difficult part from Cambridge Bay to Fort Ross by way of King William Island, Peel passage and Bellot strait. That is the only part of the southern (shallow and narrow) route that has always been difficult, even in late summer, and still often is. For example it was there that the Franklin expedition got stuck.

    • There’s plenty of evidence of widespread whale hunting and fishing in the MWP in the Canadian Archipelago, as well.

      Those days are long gone, made impossible by the massive increase in sea ice in the lead-up to the LIA.

      Biodata clearly shows that current levels are only a little bit down from the extremes of the LIA, far higher than the MWP and that the first 3/4 of the current interglacial often had basically zero summer sea ice

      Levels at the moment are actually ANMALOUSLY HIGH.

      If you rotate the chart above 180 degrees , you will see how well it coincides with the GISP Greenland temperature data.

    • The Inuit did not invent whaling boats and kayaks nor travel all the way to Greenland because there there was no open water in the summer. They obviously used them for hunting sea mammals which provided their food for the winter and the oil to fuel their winter-time oil fires. They travelled to Greenland in the whaling boats.

      The current Inuit came over from Siberia about 1,000 years ago. A little known fact. Strange that Siberian Husky does not ring any bells. So, this is not evidence for earlier than 1,000 AD ice conditions but the Inuit would not have survived without open ocean in the summer fairly consistently over the last 1,000 years. The earlier cultures did not use kayaks and whaling boats but some type of floating whale skin bag which also indicates open water.

      So, the North-west Passage has probably always mostly melted out every summer for thousands of years. Nothing has changed.

      • Climate is always changing. It’s just that during interglacials like the Holocene, the change is cyclical.

        It is during glacials, too.

      • Yes, the Thule inuits dispersed so fast from Alaska to Greenland that the process can’t be resolved by radiocarbon dating. They didn’t do that by walking. They used umiaqs and kayaks.

        When the Norse colonized southern Greenland ca AD 990, they found no people there, only old hut ruins and stone tools. The Cape Dorset Eskimo which had no kayaks and were dependent on hunting seals on the winter ice had left southern Greenland because it was to warm.

        It wasn’t until about a century later they met up with the Thule inuits which had arrived from the other direction and displaced the remaining Cape Dorset people.

    • “something markedly different from 20th century multi year, multi ice breaker passages on widely separated occasions…”

      Griffie, could you please provide a list of the failedefforts to go through the Nortwest Passage, e. g. 1906-1950?

  27. Everyone who studies ice knows the masie data is NOT
    SUITABLE for year to year comparisons.
    They even tell you this explicitly.

    This analysis is a fraud.

    • BEST is the FRAUD, mosh…

      Paid for by a bunch of far left totalitarians.

      And you have lowered your integrity to basically zero by letting yourself be their mouthpiece.

      • “BEST is the FRAUD, mosh…

        Paid for by a bunch of far left totalitarians.

        And you have lowered your integrity to basically zero by letting yourself be their mouthpiece”

        Charles & David Koch were the largest donors of the 1st phase of the BEST project.
        I don’t think “far left totalitarian” has ever been an accurate description of either brother.
        I recall that many regulars here were supportive of Richard Muller’s plan at the time, right up until his conclusions didn’t match their preconceived notions.
        A common criticism of climatology studies is that they aren’t transparent enough.
        The code, raw data, methodology, etc are all available for the BEST project.
        There’s been ample time to expose their obvious manipulations & fudging.

      • “Charles & David Koch were the largest donors of the 1st phase of the BEST project.”

        First year only.

        Then they realised they had been CONNED.

      • “There’s been ample time to expose their obvious manipulations & fudging”

        Yes , it has been exposed. MANY times.

    • This statement is a fraud.
      They explicitly state that their data is better than any other source for day to day activity.
      Better.

      Therefore it must be fit for year to year comparisons.
      Then they say that this better data is not as good to use for comparisons because the other data fits in with AGW theory better.
      You know that.
      That is why you tie yourself in knots defending the indefensible.
      Sad but understandable

      • “Therefore it must be fit for year to year comparisons.”
        No. They say quite explicitly that it is not better for year to year comparisons.

      • PS: From your comment:”A good analyst would compare all datasets.” I tried so with the extent-data from JAXA and the monthly data from NSIDC:

        (I used a 13a loess smoother, the thick line)
        All the used records show the same behaviour which not depends on the data sets.

  28. Here is what I did last week. “Eyeballed” the Danish Met temp record north of 80.
    Data starts in 1958.
    Noted each year when the daily mean did NOT go above the annual mean curve.
    1996, 2004, 2005, 2006, 2010, 2013, 2017.
    Of course, the weird variable has been the storms that push the ice around.
    Bob Hoye

    • Actually, years with the daily mean consistent with the long term mean curve indicate that there was very little open water. Years with winter temps above the long term mean indicate open water. That should be obvious.

    • Very interesting piece of analysis..

      All but one year that never went above the ERA40 summer average were this century.

      That is actually quite remarkable !!!


  29. (Diagram showing area weighted Arctic (70-90oN) monthly surface air temperature anomalies since January 1920, in relation to the WMO normal period 1961-1990).
    Nothing is happening in the Arctic temperature-wise that hasn’t happened before in Fred Singer’s lifetime.

    • Darn, look at that cold peak in 1978/79. !

      No wonder the alarmista scammers and trolls want to start all their charts then.

    • The anomalous highs of the 30’s and 40’s are indicative of a great deal of heat rejection into the Arctic atmosphere and through it to space. The follow on cold period is therefore indicative of that removal of heat from the weather system. That process was complete by 1965, after which temps were fairly flat as ice had grown and cut off heat rejection from sea to atmosphere. By 1980, sea water temps under the ice had risen to the point where the ice was no longer self sustaining and began to break up. This is essentially why the 1980 to 2000 warming trend looks exactly like the 1920 to 1944 trend. The differences are about 97% in the degree of fiddle. It is a fraction of a degree and no one can say that it is accurate so it is meaningless.

      This is what matters now:
      How will they attempt to fiddle past and present data to hide the cooling phase ( complete with ice extent expansion) that is presently underway? And will we let them do it?

    • Please read the small letters under this graph;

      “Note to the three Arctic temperature diagrams above: As the HadCRUT4 data series has improved high latitude data coverage (compared to the HadCRUT3 series) the individual 5ox5o grid cells has been weighted according to their surface area. This is in contrast to Gillet et al. 2008 which calculated a simple average, with no consideration to the surface area represented by the individual 5ox5o grid cells.”

      Mr. Humlum feels free to recalibrate the data he has not been involved in collecting or processed, the curve he showes is pulled right out of his ass.

      • If you don’t correct the data for grid size you will violently exaggerate the data from near the poles. Not so long ago in anothe thread Steven Mosher assured us that of course, everybody corrects for grid area. He was wrong as usual.

        Consequently Humlum’s ass is much better than yours.

  30. Did it occur to you that you have been brainwashed? What is the the problem with the ability to digest fact? A blockage of a part of the brain that has been conditioned to refute it. One of the facts that is being blocked is that heat melts ice. It’s not an easy one to refute. Keep trying, or perhaps go back to the drawing board. Maybe you can prove that there sun is losing heat, or the earth is flat. Good luck with your “research”. This is a massive failure and exposure of a brainwashed condition. There are professionals that can help you. Please look them up and return to a healthy state of mind. I wish you the best of luck with your health.

    • Did it occur to you that you can’t handle the truth?

      The indisputable fact is that Arctic sea ice has flatlined for a decade. The trend since 2012 is up.

      From 1979, the iciest year in the Arctic in a century, the trend was down until 2012. Meanwhile, the trend from 1979 to 2014 in Antarctic sea ice was steeply up. How then could steadily rising CO2 over that interval possibly be responsible for Arctic sea ice decline?

      And since the increase in CO2 has persisted since 2012, how do you explain Arctic sea ice gain?

      Facts are stubborn things.

      • The extent has been pretty constant – constantly low – but the volume is declining and also the thickness…

        Thick multi year ice has declined dramatically.

        The ice condition is such a ‘good’ melt season will inevitably see a new sub 2012 record: only a cold summer has helped us dodge the bullet this year already (and we have a month to go)

      • “Thick multi year ice has declined dramatically.”

        LIAR.

        Russian charts show hat multi-year ice ahs increased over the last ten years.

        You just make your CRAP up, don’t you , griff.

      • “constantly low”

        LAIR, You KNOW that the current extent is ANOALOUSLY HIGH for the last 10,000 year.

        Far HIGHER than the MWP. The only period there has been more Arctic sea ice was during the LIA, the coldest period in 10,000 years.

      • AndyG55 August 12, 2017 at 3:20 am
        “constantly low”

        LAIR, You KNOW that the current extent is ANOALOUSLY HIGH for the last 10,000 year.

        And do you know that the graph you have posted twice now ends in 1950? Also including the legend is missing which would explain what is being plotted.
        The paper you got it from says:
        “The minimum sea-ice extent is reached in September (Fig. 2). In the last four decades, the extent and thickness of Arctic sea ice has decreased dramatically (e.g. Johannessen et al., 2004; Serreze et al., 2007; Stroeve et al., 2007; Cavalieri and Parkinson, 2012; Laxon et al., 2013; Lindsay and Schweiger, 2015), and this decrease seems to be by far more rapid than predicted by any climate model (Stroeve et al., 2007, 2012). The Chukchi Sea has become completely ice-free during the summer of the last few years (Figs 2 and 3).”

      • AndyG55 August 12, 2017 at 3:18 am
        “Thick multi year ice has declined dramatically.”

        LIAR.

        Russian charts show hat multi-year ice ahs increased over the last ten years.

        You just make your CRAP up, don’t you , griff.

        Well your producing an unreferenced graph would suggest that you are the one making things up.

        Here’s some referenced data:

        The age of the sea ice in the Arctic Ocean at winter maximum in March 1985 (left) compared with March 2016 (right). The darker the blue, the younger the ice. The first age class on the scale (1, darkest blue) means “first-year ice,” which formed in the most recent winter. The oldest ice (7+, white) is ice that is more than seven years old. Historically, most of the ice pack was many years old. Today, only a fraction of that very old ice remains. NOAA Climate.gov maps, based on NOAA/NASA data provided by Mark Tschudi.

        https://www.climate.gov/news-features/understanding-climate/noaas-2016-arctic-report-card-visual-highlights

  31. To Gluteus Maximus; Your statement that artic Sea Ice has flattened for the last 10 years, and that 1979 was at the top the last century, put You in the center of Your self.

    • Quite a cryptic statement on your part.

      My statement, OTOH, is as plain and factual as can be. It is objectively the fact that 1979 was at or near the highest Arctic ice year of the past century, and that Arctic sea ice extent has remained the same on average for the past decade.

      • Objective fact is too strong. We don’t have reliable satellite measurements before 1979 so we are always going to be talking about estimates and reconstructions. These will differ from study to study. The reconstruction of Don, Connolly, Connolly and Soon shown above is slighlty different from that of Walsh et al. Both show significant loss of sea ice since 1979 not previously seen. Walsh does not have 1979 at or near the highest of the last century, and neither does Don et al, although they show it nearer the top.

  32. Of course we have detailed ice records going back to well before the satellite record…

    This article documents how records from all sources back to 1850 have been assembled, collated and checked to produce detailed information:

    https://www.carbonbrief.org/guest-post-piecing-together-arctic-sea-ice-history-1850

    And the conclusions from that research are quite definite:

    “Most fundamentally of all, the new dataset allows us to answer the three questions we posed at the beginning of this article.

    First, there is no point in the past 150 years where sea ice extent is as small as it has been in recent years. Second, the rate of sea ice retreat in recent years is also unprecedented in the historical record. And, third, the natural fluctuations in sea ice over multiple decades are generally smaller than the year-to-year variability.”

    • I would dearly like to know how they derived the “annual minimum” for Siberia 1850-1900. During that period two (2) ships passed through the Northeast Passage, Vega (the first ever) in 1878 and Fram (only as far as the Laptev sea) in 1893. There are no other data for the stretch from the Yenisey to the Chukotka.

    • Val,

      What years in the past century IYO had higher ice than 1979? Maybe 1918 or 1919, but sea ice melted rapidly during the early 1920s, and stayed low until the late ’40s, when it started growing again, with wide annual variability, until the late ’70s.

      • From above:

        Other reconstructions and satellite interpretations show one year in the 1970s higher than 1979, but all show years as low as now in the past.

      • Gloteus, It is worthwhile looking for more recent studies. Things have come on a long way since 1980. As pointed out in the paper co-authored by Soon (Don et al) there was little access to USSR or Russian data then, but these data sets have now become available.

  33. That’s simply BS. I guess that any scientific studies like Kinnard et al(2011) do not convince You, so I will take another approach. We Norwegians have been doing a lot of stuff in the Arctic for several hundred years and any story that the Artic sea ice was the highest in 1979 for the past century is simply laughable. It was a bit higher in the mid seventies. But the big picture is a all over decline with the usual up and downs. I guess Your story is plausible when told in Huntsville Alabama, tell the same story to an old sealhunter in Tromsø, Norway, and You will experience what a Hakapik is.

    • Yes – here is some excellent Norwegian research done recently, showing the ice state is not just in trouble in the summer:
      https://www.nature.com/news/incredibly-thin-arctic-sea-ice-shocks-researchers-1.21163

      “A daring 2015 expedition that collected rare measurements of the Arctic in winter found that sea ice near the North Pole was thinner and weaker than expected.
      “This thinner and younger ice in the Arctic today works very differently than the ice we knew,” says Mats Granskog, a sea-ice researcher at the Norwegian Polar Institute in Tromsø and chief scientist on the expedition, called the Norwegian Young Sea Ice (N-ICE2015) project. “It moves much faster. It breaks up more easily. It’s way more vulnerable to storms and winds.” “

    • Val,

      We actually have satellite data from the 1960s and ’70s showing what a huge outlier 1979 was. How many Norwegians were in the Canadian Arctic then?

      Scandinavian observations show that Arctic sea ice was as low in the 1920s, ’30s and ’40s as now, recovered some in the 1950s to ’70s, then peaked in 1979.

      If there are to be any hakapiks to the head, the target will be yours.

      • Gloateus, we Norwegians with a Polar History with at least some merit, get pissed when You clueless tells us that the state of the Arctic sea ice is about the same today, as 70 – 80 years ago. This is utterly nonsense and there is a Mountain of evidence that this is utterly nonsense. If You have a mildly ice-strengthened vessel, You will tomorrow reach the Pole in a week from Svalbard. The USCGC Healy reached the Pole last year 10 days early, there was hardly no need for icebreaking, it was largely slush.

        Why the hell did not Amundsen – who knew a little bit about Artic Ice – use an Icebreaker in the twenties in stead of two tries with flying boats and one with a Zeppeliner to reach the Pole? Lack of imagination? There was a lot of quit heavy icebreakers available in Norway, in the Baltic and in the Barents area every year from may to oktober in the twenties and the thirties, but nobody thought of that until 1977 when Arktika was the first surface ship to reach the Pole?

        Get real.

      • Val,

        You get real. You’re spouting nonsense. My dad and granddad were in the Canadian and Alaskan Arctic in the 1930s, and I’ve been there during every decade since the 1960s, so have seen or heard of the changes in sea ice of the past century.

        There are actual ice observations from the ’20s and ’30s, plus historical records of Arctic navigation then, to show that sea ice extent was comparable to now.

        Had there been an icebreaker capable of penetrating the central Arctic in 1928, Amundsen couldn’t have afforded it. He was bankrupt. The scarce and rotten sea ice of the early 1920s is why he couldn’t cross the Bering Strait on sleds, as planned.

        From November 1922:

        “The Arctic ocean is warming up, icebergs are growing scarcer and in some places the seals are finding the water too hot, according to a report to the Commerce Department yesterday from Consulafft, at Bergen, Norway.

        “Reports from fishermen, seal hunters and explorers all point to a radical change in climate conditions and hitherto unheard-of temperatures in the Arctic zone. Exploration expeditions report that scarcely any ice has been met as far north as 81 degrees 29 minutes. Soundings to a depth of 3,100 meters showed the gulf stream still very warm. Great masses of ice have been replaced by moraines of earth and stones, the report continued, while at many points well known glaciers have entirely disappeared.

        “Very few seals and no white fish are found in the eastern Arctic, while vast shoals of herring and smelts which have never before ventured so far north, are being encountered in the old seal fishing grounds.”

        Even you must know that in the 1930s and ’40s the Northeast Passage along Siberia was open, which helped the USSR fight the war.

      • Although I’d be surprised if there were in 1928 a steam icebreaker capable of penetrating multiyear Arctic Ocean sea ice north of Greenland. Seasonal ice in the Baltic is a different kettle of herring.

      • So he could afford two Dornier Do J flying boats and a Zeppeliner, but not hire a ice – breaker? Are You telling me that the reason why nobody reached the Pole before 1977 was a matter of economics?

      • Val,

        That was a big reason. The USSR did it just as a publicity stunt.

        Amundsen didn’t have to pay for the aircraft involved in the attempt to rescue airship Italia. You should be ashamed of your lack of knowledge of Norwegian history.

        Also however, if you know of an ocean-going icebreaker capable of reaching the North Pole in 1928, please direct me to it. Steam ice breakers designed to keep open shipping lanes into Baltic Sea ports simply wouldn’t cut it in the Arctic Ocean above 80 degrees N latitude.

      • Russian ship Yermak might still have been the most powerful polar ice breaker in the world in 1928, when she was 30 years old. But whatever ship did enjoy that title, it wouldn’t have been much more powerful.

        https://en.wikipedia.org/wiki/Yermak_(1898_icebreaker)

        She was capable of reaching Spitsbergen. The North Pole, not so much.

        So Amundsen couldn’t reach the Pole on the surface for both economic and technical reasons, after his plan to drift there locked in pack ice failed and he went broke.

      • Another point about Amundsen is that he learned the skills and techniques, such as dog sleds, which enabled him to reach the South Pole, from the Netsilik people of the then NWT in 1903-05. Some of their elders who knew him were still alive when my granddad and dad were there in the 1930s.

        In their Ford Trimotor, they flew around Catholic priests who demanded Arctic fox pelts from the Indians of the Yukon and NWT, in payment for their having preyed for them all winter in comfort. Some of the same missionaries also tried their scam on the Eskimos, to include the Netsilik.

        Canada refers to the Netsilik as “Inuit”, although I don’t know how mutually intelligible is their dialect with that of Greenland Inuit. I do know it’s almost not intelligible to the Inupiat people of northern Alaska, and not even the same language as the Yupik of western Alaskan and eastern Siberian Eskimos.

      • Just look at the publications. Even Willie Soon agrees that the summer ice extent now is much lower than at any time in the last century.

      • Gloateus, I’m sorry, but You are clueless, here is a list of icebreakers, a lot of these (pre 1940) would with ease reach the Pole to day;

        https://en.wikipedia.org/wiki/List_of_icebreakers#Steam-powered

        And Amundsen did no try to reach the Pole by drifting over it, that was Nansen with Fram. Cut Your drivel, learn the Science;

        Vinnikov et al. (1999)
        Walsh and Chapman (2001)
        Kinnard et al (2008)
        Kinnard et al (2011)

        And here is a fresh one;

        http://onlinelibrary.wiley.com/doi/10.1111/j.1931-0846.2016.12195.x/full

        But I guess it won’t help, You will prefer Tony Heller drivel.

      • Val,

        You continue to embarrass yourself with your total ignorance of the events upon which you presume to comment.

        Amundsen most certainly did try to reach the Pole by drifting, in Maud.

        From the Wiki entry on Amundsen:

        In 1918, an expedition Amundsen began with a new ship, Maud, lasted until 1925. Maud was carefully navigated through the ice west to east through the Northeast Passage, now called the Northern Route (1918–20).
        With him on this expedition were Oscar Wisting and Helmer Hanssen, both of whom had been part of the team to reach the South Pole. In addition, Henrik Lindstrøm was included as a cook. He suffered a stroke and was so physically reduced that he could not participate.
        The goal of the expedition was to explore the unknown areas of the Arctic Ocean, strongly inspired by Fridtjof Nansen’s earlier expedition with Fram. The plan was to sail along the coast of Siberia and go into the ice farther to the north and east than Nansen had. In contrast to Amundsen’s earlier expeditions, this was expected to yield more material for academic research, and he carried the geophysicist Harald Sverdrup on board.
        The voyage was to the northeasterly direction over the Kara Sea. Amundsen planned to freeze the Maud into the polar ice cap and drift towards the North Pole (as Nansen had done with the Fram), and he did so off Cape Chelyuskin. But, the ice became so thick that the ship was unable to break free, although it was designed for such a journey in heavy ice. In September 1919, the crew got the ship loose from the ice, but it froze again after eleven days somewhere between the New Siberian Islands and Wrangel Island.
        During this time, Amundsen participated little in the work outdoors, such as sleigh rides and hunting, because he had suffered numerous injuries. He had a broken arm and had been attacked by polar bears.[13] Hanssen and Wisting, along with two other men, embarked on an expedition by dog sled to Nome, Alaska, more than 1,000 kilometres away. But they found that the ice was not frozen solid in the Bering Strait, and it could not be crossed. They sent a telegram from Anadyr to signal their location.
        After two winters frozen in the ice, without having achieved the goal of drifting over the North Pole, Amundsen decided to go to Nome to repair the ship and buy provisions. Several of the crew ashore there, including Hanssen, did not return on time to the ship. Amundsen considered Hanssen to be in breach of contract, and dismissed him from the crew.
        During the third winter, Maud was frozen in the western Bering Strait. She finally became free and the expedition sailed south, reaching Seattle, Washington, in the US Pacific Northwest in 1921 for repairs. Amundsen returned to Norway, needing to put his finances in order. He took with him two young indigenous girls, the adopted four-year-old Kakonita and her companion Camilla. When Amundsen went bankrupt two years later, however, he sent the girls to be cared for by Camilla’s father, who lived in eastern Russia.[14]
        In June 1922, Amundsen returned to Maud, which had been sailed to Nome. He decided to shift from the planned naval expedition to aerial ones, and arranged to charter a plane. He divided the expedition team in two: one part was to survive the winter and prepare for an attempt to fly over the pole. This part was led by Amundsen. The second team on Maud, under the command of Wisting, was to resume the original plan to drift over the North Pole in the ice. The ship drifted in the ice for three years east of the New Siberian Islands, never reaching the North Pole. It was finally seized by Amundsen’s creditors as collateral for his mounting debt.
        The attempt to fly over the Pole failed, too. Amundsen and Oskar Omdal, of the Royal Norwegian Navy, tried to fly from Wainwright, Alaska, to Spitsbergen across the North Pole. When their aircraft was damaged, they abandoned the journey. To raise additional funds, Amundsen traveled around the United States in 1924 on a lecture tour.
        Although he was unable to reach the North Pole, the scientific results of the expedition, mainly the work of Sverdrup, have proven to be of considerable value. Many of these carefully collected scientific data were lost during the ill-fated journey of Peter Tessem and Paul Knutsen, two crew members sent on a mission by Amundsen. The scientific materials were later retrieved by Russian scientist Nikolay Urvantsev from where they had been abandoned on the shores of the Kara Sea.[15]

        https://en.wikipedia.org/wiki/Maud_(ship)

        The 1925 Dornier flying boats were paid for by American explorer Lincoln Ellsworth and his backers.

        You still haven’t provided an instance of an icebreaker in which Amundsen could have reached the pole in the 1920s. Nor do you recognize the fact that he could not have afforded one had one been available. The Maud expedition broke him, and it was all he could afford.

        You also still apparently labor under the misconception that Amundsen died in an attempt to reach the Pole in 1928. Nothing could be farther from the truth, as I’ve repeatedly showed you. He was a small part of the international expedition to search for and rescue the crew of airship Italia. He died in a French Navy seaplane participating in the attempt.

  34. Some of the comments opposing Javier’s conclusions fit well the ‘denial-acceptance’ range. ‘Denial and isolation’ is the first of five in that range. It implies that his opponents consider him to be right.
    The observations over the last 10 years of unchanged arctic sea ice extent and the trend to an earlier end of the melt season make a strong case for his modest conclusions.

  35. teerhuis August 13, 2017 at 12:31 pm

    The observations over the last 10 years of unchanged arctic sea ice extent and the trend to an earlier end of the melt season make a strong case for his modest conclusions.

    The observations over the last 10 years include the ten lowest extents in the record and show a very fluctuating record. This year will probably pass the 10th lowest minimum extent (2005) in a couple of days with a month to go. The ‘trend’ to a earlier end of the melt season reflects this variability:
    “According to the trend and methodology, the 2017 melt season is projected to end on day 255 (September 12) ± 1 week.”
    So somewhere between 249 and 262, so a melt season length between 186 days (shortest by 1 day) and 199 (2nd longest by 2 days)! I wouldn’t say that makes ‘a strong case’.

  36. Changes in recent arctic sea ice (i can’t say for past instances) appears to be from changes in the winter season. Indeed, it seems the summer temperature is trending a little lower. CO2 has no place in sea ice extent discussions if we think about the greenhouse effect, as the greenhouse effect doesn’t pick and choose the time of year.

    If you look back at reanalysis of arctic winter temperatures going back to 1958, you can see that it wasn’t uncommon for there to be well above average temperatures in winter, but that their duration was much smaller, before returns to average or below average conditions. To me that says those warm instances previously were weather pattern related. So, rather than looking at a direct CO2 causation, people need to be looking at weather pattern changes in winter over the past 60 years or so (i’m no specialist and also don’t have time) and then go looking for what caused those changes.

    I can see scenarios where summer sea ice extent could all but disappear. It would need a spring and summer of 2012 (not temperature driven, so therefore not CO2 driven) and a winter/spring of 2016/2017(weather system driven). After a few years of that, it would be just about gone.

    Alas, as we saw in this melt season, starting at a record low starting point, the weather isn’t always going to play ball. Just like for 2012 the starting extent was respectable, all the damage was then done in the late spring and summer. Still, if you keep starting out at 2016/2017 levels, at some point the right numbers will come up.

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