New study shows Arctic sea ice extent ~6000 years ago was much less than today

This is interesting, somehow the Earth managed to reduce a good portion of the Arctic Ice Cap during the Holocene Climate Optimum from approximately 10,000-6,000 years ago without the help of the industrial revolution, fossil fuels, or automobile emissions.

This new paper published in Quaternary Science Reviews finds Arctic sea ice extent and thickness was much less than present-day conditions and according to the authors,

“Arctic Ocean sea ice proxies generally suggest a reduction in sea ice during parts of the early and middle Holocene (∼6000–10,000 years Before the Present) compared to present day conditions.”

The authors show how  8 different proxy studies reveal extended periods lasting hundreds of years without perennial sea ice in the Arctic [ice-free conditions], and find solar insolation explains these changes. See figure 4 from the paper below.

The top graph shows simulated annual mean sea ice thickness [orange curve] was much less during the Holocene Climate Optimum ~13,000-6,000 years ago compared to the end of the 20th century at right side of graph. The bottom graph shows multiple proxies of sea ice with darker green indicating periods of less sea ice. Modern sea ice is at high levels in comparison to the rest of the Holocene.

Fig. 4.
Annual mean sea ice thickness for the three different simulations (Panel a) compared with results from published paleo-sea ice studies (Panel b). Black curve: constant surface albedo; red curve: dynamic surface albedo parameterization. The simulation implemented with a dynamic surface albedo parameterization was run from present time and backwards to address the importance of the initial state of the sea ice cover. The annual mean sea ice thickness from this simulation (orange curve) reveals a hysteresis of ∼1000 years. The annual mean insolation at 80°N shown with a stippled curve is based on the algorithm presented by Berger (1978). To compare the results from different paleo-sea ice studies a scale of sea ice concentration was inferred using the approach by Jakobsson et al. (2010). This scale must be considered as highly qualitative because none of the paleo-sea ice proxies provide absolute measures of past sea ice concentrations.

The paper:

Arctic Ocean perennial sea ice breakdown during the Early Holocene Insolation Maximum 

Christian Stranne, Martin Jakobsson, Göran Björk

Abstract

Arctic Ocean sea ice proxies generally suggest a reduction in sea ice during parts of the early and middle Holocene (∼6000–10,000 years Before the Present) compared to present day conditions. This sea ice minimum has been attributed to the northern hemisphere Early Holocene Insolation Maximum (EHIM) associated with Earth’s orbital cycles. Here we investigate the transient effect of insolation variations during the final part of the last glaciation and the Holocene by means of continuous climate simulations with the coupled atmosphere–sea ice–ocean column model CCAM. We show that the increased insolation during EHIM has the potential to push the Arctic Ocean sea ice cover into a regime dominated by seasonal ice, i.e. ice free summers. The strong sea ice thickness response is caused by the positive sea ice albedo feedback. Studies of the GRIP ice cores and high latitude North Atlantic sediment cores show that the Bølling–Allerød period (c. 12,700–14,700 years BP) was a climatically unstable period in the northern high latitudes and we speculate that this instability may be linked to dual stability modes of the Arctic sea ice cover characterized by e.g. transitions between periods with and without perennial sea ice cover.

http://www.sciencedirect.com/science/article/pii/S0277379113004162?np=y

h/t to The Hockey Schtick

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87 Responses to New study shows Arctic sea ice extent ~6000 years ago was much less than today

  1. Box of Rocks says:

    Now we need to send in the archaeologist to find the coal fired power plants and GMC Yukons….

    That is going to be one big dig. But hey people will be employed!

  2. Ric Werme says:

    There were a lot of interesting things going on 6000 years ago, I saved some in http://wermenh.com/climate/6000.html

    Most of my savings were about glaciers around the world (hello Oetzi!), but I also have this:

    2008 Oct 20: Less ice in the Arctic Ocean 6000-7000 years ago
    “Recent mapping of a number of raised beach ridges on the north coast of Greenland suggests that the ice cover in the Arctic Ocean was greatly reduced some 6000-7000 years ago. The Arctic Ocean may have been periodically ice free.”

    This includes a ruined settlement left by the Independence I Culture in North Greenland abandoned at least 4,000 years ago.

    Hey, the link still works, see http://www.ngu.no/sciencepub/eng/pages/Whatsup_20_10_08.html

  3. cnxtim says:

    We have never had to look any further than our Sun to see whichis the only force that matters when it comes to the Earths climate.
    It is positively ludicrous to propose the a minute increase or decrease in CO2 can have any significant effect.,
    Consequently one must accept the only logical explanation, That this preposterous hypothesis is all about political control,,and science be damned.

  4. JustAnotherPoster says:

    Good, Decent well done science. Can’t fault it really. Suprised it got published as it doesn’t fit the its warmer than ever and were all going to die MEME.

  5. Sooo disappointing….. “Our work points to the strong surface albedo feedback as the common denominator between the sea ice minimum before 6000 years ago and the present diminishing trend. However, at the same time as our simulations show the importance of the surface albedo feedback, there are likely two distinctly different underlying causes for the feedback to kick in: increased insolation (past) and increased GHG levels (present). We also speculate that climatically unstable periods such as the Bølling–Allerød period (c. 12,700–14,700 ”

    If increased insolation caused reduced ice in the past, whi do they assume its GHG levels in the present.

    ARGHHHHHHHH

  6. hunter says:

    Skeptics proven right again.
    We have been questioning the validity of the AGW claim that Arctic sea ice is
    1- at unprecedented low levels
    2- dangerous to the climate when it is low
    now we see this is the case.
    Hyping AGW is lucrative, and popular, but that does make it correct.

  7. Alan Robertson says:

    cnxtim says:
    March 24, 2014 at 5:17 am

    We have never had to look any further than our Sun to see whichis the only force that matters when it comes to the Earths climate.
    It is positively ludicrous to propose the a minute increase or decrease in CO2 can have any significant effect.,
    Consequently one must accept the only logical explanation, That this preposterous hypothesis is all about political control,,and science be damned.
    ____________________________
    Well, you are correct about the political part. Perhaps you could provide links to historical data which show the Sun’s link to climate and you’ll be right about that, too. Do any such studies hold under scrutiny? To say the Sun is the primary source of energy is one thing, but saying the Sun is the primary driver of Climate is another thing, unproven to date.

  8. Steve Keohane says:

    Yup, sea level was 2 meters higher 4-6000 years ago.

  9. Peter Taylor says:

    As Ric Werme says, this is old-hat, and I think now stuffed with a few new feathers by computer modellers. Norwegian real scientists found the north Greenland beach structures – showing evidence of wave action on a coastline where there is now ‘permanent’ ice, and carbon-dated it to the period 8000-6000BP (reviewed in my book Chill, 2009). For the same time-period, other real scientists in my home country of Somerset discovered that the lake-village dwellers ate Pelicans for breakfast (European birds now found only in Greece and the Danube delta)! Recent flooding may bring the lake-villages back, but it will take a lot of global warming to encourage the Pelicans to return. Greenpeace campaigners please note: this previous Arctic meltdown did not release methane hydrates that fried the planet.

  10. beng says:

    Notice these types of papers don’t go into fearmongering mode when talking about previous natural changes. It’s only when talking about similar changes that might happen now that the fearmongering emerges. What about the poor polar bears back then? The poor seals? The delicate Arctic ecosystem?

  11. Alan Robertson says:

    To cnxtim:
    The radiative energy reaching the Earth from the Sun varies both cyclically and randomly, but so far, the changes don’t correlate to historical climate change. It may well be that the Sun, in concert with other forces we don’t yet understand, such as the Solar wind influence > cosmic radiation > cloud formation is a major factor in our changing climate. There is just too much going on that we don’t yet understand.

  12. Gary says:

    It’s 99% modeling results with a tiny bit of support from other studies using paleo data, some of which the authors say is contradictory. The only thing worthwhile coming from it is that models can cut both ways, which hardly supports the paper’s conclusion.

  13. philjourdan says:

    The truth is the hysteria of the ice caps is based upon such a miniscule window into the behavior of the ice caps that no logical conclusions can be drawn. Yet those seeking to advance their alarmist agenda still use it as some sort of absolute measuring stick.

  14. Climate philosophy – about as `scientific` as say alchemy, astrology or reading palms. The corrupt Cult of Globaloneywarming just highlights the poverty of modern critical thinking. Truly a dark age in some ways.

  15. Tom J says:

    Well at least now we don’t have to worry about any emails being sent from Michael Mann to Phil Jones inquiring whether they can get one of the editors at Quaternary Science Reviews sacked.

    Maybe.

  16. Alan Robertson says:

    Ferdinand (@StFerdinandIII) says:
    March 24, 2014 at 5:52 am
    __________________
    Engelbeen, is that you?

  17. Henry Clark says:

    Although generally preferring more direct data than model simulations, there are quite a number of studies showing the Holocene Climate Optimum had greater warmth than now, higher sea level, more arctic vegetation (fitting the warmth), etc. Some are listed within co2science.org

    And naturally solar forcing was high then.

    Variation in solar forcing at Earth, both from Milankovitch cycles and from variation in solar activity itself, is the prime driver of climate on most timescales, including through influence on cosmic rays (also affected by geomagnetic variation and movement around the galaxy):

    As a Dergachev et al 2004 paper flatly notes, known data “proves that cosmic rays were the main factor affecting the weather and climate during tens of thousands of years.

    References and far more are within my usual http://tinyurl.com/nbnh7hq link.

    Such includes implicit debunking of various common Big Lies; for example, one common falsehood is that solar activity was flat during the 1970s->1990s warming, aided by rewriting ACRIM data with PMOD, but there were too many more independent neutron monitors to get those rewritten, so observe what a plot 2/3rds of the way down in the prior link shows.

  18. Tom in Florida says:

    re: cnxtim says: March 24, 2014 at 5:17 am
    ————————————————————————————————————————
    Please do not confuse TSI and insolation. The chart shows higher insolation at 80 N because approx 10,000 years ago obliquity was 24 degrees and perihelion was at summer solstice. One would certainly expect less northern sea ice under those conditions which are a result of Earth’s orbit not changes in the Sun’s output.

  19. docstephens says:

    It’s the wobble, precession of the axis. The Earth was closest to the sun in the Northern Hemisphere summer (July through September) during that period causing the insulation minimum. The sea ice extent and thickness should have been at a maximum in the Southern Hemisphere approximately 13000 to 8000 BP. We are now at perihelion in early January, therefore moderating NH winters. The asymmetrical distribution of continental crust complicates the matter.

  20. Leo Geiger says:

    I see this paper doesn’t get the “Claim:” characterization added to the blog post title. I guess someone likes some aspect of the paper. That’s interesting, since the conclusion comes from modelling:

    The Arctic sea ice conditions are simulated from the later part of the last Glacial Maximum (17,000 years BP) and throughout the Holocene using the coupled atmosphere–sea ice–ocean column model CCAM (Stranne and Björk, 2011).

    Climate models are OK now?

    Later it is noted that the paleo-sea ice records don’t necessarily support ice free conditions found in the model, while they do support a reduction in ice extent:

    Whether or not the summer sea ice disappeared in the Holocene over the entire Arctic Ocean is far from resolved from paleo-proxies, although the majority of published results seems to indicate a substantial decrease in the earlier and middle part of the Holocene (Fig. 4b).

    But yes, they are arguing that it is possible the Arctic could have been ice free during some part of the period from 6000-12000 years ago based on their models. So do the authors of this paper think this means the current decline in Arctic sea ice has a natural cause? Nope. In their own words:

    However, at the same time as our simulations show the importance of the surface albedo feedback, there are likely two distinctly different underlying causes for the feedback to kick in: increased insolation (past) and increased GHG levels (present).

  21. Espen says:

    Not very surprising. Hardangervidda in Norway was a forest back then.

  22. jauntycyclist says:

    its open knowledge?

    Holocene climatic optimum

    ‘Of 140 sites across the western Arctic, there is clear evidence for warmer-than-present conditions at 120 sites. At 16 sites where quantitative estimates have been obtained, local HTM temperatures were on average 1.6±0.8 °C higher than present. Northwestern North America had peak warmth first, from 11,000 to 9,000 years ago, while the Laurentide ice sheet still chilled the continent. Northeastern North America experienced peak warming 4,000 years later. Along the Arctic Coastal Plain in Alaska, there are indications of summer temperatures 2–3 °C warmer than present.[5] Research indicates that the Arctic had substantially less sea ice during this period compared to present.’

    “The Hans Tausen Iskappe (ice cap) in Peary Land (northern Greenland) was drilled in 1977 with a new deep drill to 325 m. The ice core contained distinct melt layers all the way to bedrock indicating that Hans Tausen Iskappe contains no ice from the last glaciation; i.e., the world’s northernmost ice cap melted away during the post-glacial climatic optimum and was rebuilt when the climate got colder some 4000 years ago.”

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

    better take a snapshot of that before the co2ers realise there is a wiki page they forgot to
    ‘improve’.

    if the co2ers contextualised the warming within icce age cycles no one would take any notice of them which is why they have to sex it up so the press [who don't care either way- they love sensation] have a headline.

  23. Pamela Gray says:

    Tom, thank you. Our Earth wibbles, wobbles, whirls, and varies its own intrinsic atmosphere and oceans in a fluidly dynamic dance around the ever present Sun. And I am unimpressed with these “discoveries” being marched out in front of us in order to proclaim that this has been the past but has now ceased to exist as the prime behavior of Earth, overtaken as it is by the breath of man.

    Idiots.

  24. ddpalmer says:

    So then Polar Bears as a species only emerged within the last 6,000 years? Because we know current ice conditions are driving them to extinction, so the ice conditions in the paper would have killed them all off. Meaning the current species must postdate those lower ice conditions.

  25. JimS says:

    The skeptics may be right. It’s worse than we thought.

  26. Jim Bo says:

    Someone please translate the following for the science challenged and what, if any, import it has in reference to CAGW?…

    However, at the same time as our simulations show the importance of the surface albedo feedback, there are likely two distinctly different underlying causes for the feedback to kick in: increased insolation (past) and increased GHG levels (present).

  27. Ulric Lyons says:

    “This is interesting, somehow the Earth managed to reduce a good portion of the Arctic Ice Cap during the Holocene Climate Optimum from approximately 10,000-6,000 years ago without the help of the industrial revolution, fossil fuels, or automobile emissions.”

    Between 4800 and 4400 years ago was one of the warmest periods in the Temperate Zone during the Holocene, this was when there was a rapid expansion in city building worldwide, much like the past few centuries. While in the Arctic this was one the coldest periods: http://snag.gy/BztF1.jpg

  28. jauntycyclist says:

    a bear is a bear . other bears don’t need ice to live. seals still have to go somewhere so the bears will follow them. biggest threat to polar bear is man who shoots them if they get too close.

  29. Bruce Cobb says:

    @Jim,
    1) Trenberth’s “arctic death spiral” was in effect then, and is today, but for a completely different, manmade reason. Total nonsense, of course.

  30. Magma says:

    It seems in their rush to applaud this mainstream refereed climate science paper, people have skipped over the part about mean annual insolation in the Arctic being 5 W/m^2 higher in the Early Holocene than today (for entirely understood reasons), or that the authors are comparing modeled and proxy-derived Early Holocence Arctic ice cover to modern pre-industrial ice cover.

    That the paper shows Arctic climate is extremely sensitive to external forcings.also seems to have escaped the celebrators’ notice, as does the fact that Earth is nowhere near a Northern Hemisphere insolation maximum but the ice is melting anyway.

    That’s OK. Own goals still count.

  31. jauntycyclist says:

    ulric -nice contextualising pic.
    i think if people still looking for eloquent images [a previous thread] showing global temps and where we are then yours sums it up.

  32. tommoriarty says:

    Arctic sea ice extent less 6000 years ago than today?
    Who would have thunk it?
    See…
    http://climatesanity.wordpress.com/2008/10/15/dont-panic-the-arctic-has-survived-warmer-temperatures-in-the-past/

  33. joe says:

    Yet The warmist bless the marcott 10,000 study as gospel.

  34. John F. Hultquist says:

    Jim Bo says:
    March 24, 2014 at 6:44 am
    Someone please translate . . .

    They are saying ‘We don’t have a clue and hope you won’t notice if we throw in some big words’.

    In addition, someone needs a course in writing. The phrase “ for the feedback to kick in” violates the rule to omit needless words, or in today’s lingo KISS. Why do they, given increased insolation, need a feedback or, if there was a feedback, why do they need increased insolation? Some reviewers call this “lazy writing.”

  35. Alan Robertson says:

    Magma says:
    March 24, 2014 at 7:11 am
    ___________________
    Your tirade might have been better without employing logical fallacies. It would have been more interesting if you would have given us what you think are the external forcings influencing Arctic sea ice melt. Even better, why is Antarctic ice at such great extent at Perihelion in Southern Hemisphere Summer?

  36. wws says:

    “other real scientists in my home country of Somerset discovered that the lake-village dwellers ate Pelicans for breakfast (European birds now found only in Greece and the Danube delta)!”

    Just for the record, Louisiana and the rest of the Gulf Coast are lousy with those things.

  37. Doug Hoffman says:

    The only important thing here is the detection of a period of seasonal ice cover in the Arctic during the Holocene Climate Optimum, which was much warmer than today. There is no need for the postulated “dual stability modes”. When it is cold enough the ice stays around all year; when is is warm enough it doesn’t. Also, I notice the obligitory nod to AGW in the summary of the paper. During the HCO it was increased insolation, now it’s global warming causing the move to seasonal ice. There is no science here, just unsubstantiated speculation as to the cause. I am underwhelmed.

  38. Coach Springer says:

    Study = Observation + Spin. Observation = Proxies indicate much less ice in the past. Spin = Much more ice today means CO2 catastrophe possibly imminent, assuming no summer ice is a catastrophe contrary to hundreds of years of that condition without catastrophe.

    I’m going to go with polar bears became extinct 6,000 years ago, but re-evolved. But won’t be able to again because man-made CO2 or something. (/s)

  39. Steven Mosher says:

    who believes models

    REPLY: Not all models are worthless, just like not all Mosher drive-by comments are worthless – Anthony

  40. Bob Kutz says:

    Well, Magma, the point remains; we have been told arctic ice is a tipping point feedback.

    As for the notion that the ice was thinner in the past because of higher insolation, we have been told repeatedly the insolation is a presumed constant, the sun does not vary enough to effect our climate and that current warming is unprecedented, as evidenced by arctic (and hysterically, antarctic) sea ice decline.

    To now make the claim that the lower sea ice in the distant past was caused by the sun and scientists knew this all along is disingenuous at best, completely fraudulent at worst.

    You simply cannot have a scientific theory which is confirmed by every single line of evidence, regardless of the direction that evidence takes, and still call it science.

    Even if catastrophic anthropogenic global warming were true, the evidence would still be mixed. For a perfect example of why that is, look no further than the “simple” law of gravity. Go release a helium filled balloon into the air and reconcile it to 9.8 m/s^2. Now go to the top of a building and release it on a windy day. Now consider Mars. Simple right?

    Simple laws do not play well with massive chaotic systems. Our models are horribly flawed on their best day, and the “scientists” who are clearly living in the world of advocacy rather than science, keep having to explain why their predictions are completely unskillful.

    Still think CO2 science is “simple” or “settled”? Okay then; you fail the basic scientific skepticism test. Go away and let the adults handle this.

  41. Paul Pierett says:

    What they may be overlooking is the refill of the Mediterranean Sea, Red Sea and Persian Gulf for example which took place about the time they Are looking at. That would have changed all the dynamics of the Atlantic. Conveyor Belt with warmer waters. See Johnson, Secrets of the Med Sea.

    Lot of Dynamics here that Are being over looked. ICE Age studies a must.

    Paul

  42. joe says:

    One of the positive feedbacks that will drastically increase the warming is the release of methane currently frozen in the tundra of the north. That is supposed to be a really bad thing that will create a massive spiral of warming.

    My question for the high priests of AGW is
    1) Why did the methane not get released during the Holcene period to cause unprecedented warming
    2) Since it apparently did not get released, does the methane have some form of internal mechanism that is able to differentiate between co2 warming on other forms of warming that it knows not to release unless it is co2 caused warming and
    3) if the methane did get released during the holcene warming – then who put it back in the ground to get re-released.

  43. Mike Tremblay says:

    Magma says:
    March 24, 2014 at 7:11 am
    Alan Robertson says:
    March 24, 2014 at 7:18 am
    ——————————————–
    Magma is correct. This paper is disappointing in that, although it shows that the AGW assertions that Arctic sea ice cover is at unprecedented lows are wrong, it uses current GCMs to verify what the paleoproxies are already showing. The necessity of verifying the validity of proxies which were established as valid nearly forty years ago is pointless, especially using models which we know have have been shown to be consistently wrong. This paper seems more to be an exercise in showing that the models are valid because they correspond with what the proxies are showing.

  44. jai mitchell says:

    you said, “somehow the Earth managed to reduce a good portion of the Arctic Ice Cap during the Holocene Climate Optimum

    you linked abstract said, “This sea ice minimum has been attributed to the northern hemisphere Early Holocene Insolation Maximum (EHIM) associated with Earth’s orbital cycles.

    It looks like the difference in northern hemisphere solar insolation between then and now is about 35 watts per meter squared in the summer.

    http://theinconvenientskeptic.com/wp-content/uploads/2010/11/LI-Holocene.png

    so the real question is, If the summer solar warming of the northern hemisphere has gone down by 35 watts per square meter in the summer since 4,000 B.C., how are we now approaching comparable sea ice minimums?

  45. jai mitchell says:

    In addition, the graphic shows that the ice thickness being measured is “Years BP” which is standard scientific vernacular for “1955″.

    This can easily be verified by the actual running annual average arctic ice thickness. Which in 1985 was about 2.4 meters and has since declined to about 1.4 meters (both of which are below the average value calculated for the holociene optimum.

    http://tamino.files.wordpress.com/2013/03/thick.jpg

    reference page.
    http://tamino.wordpress.com/2013/03/13/arctic-sea-ice-loss-part-2/

  46. Mike Tremblay says:

    Bob Kutz says:
    March 24, 2014 at 8:09 am
    —————————————-
    Bob, your response to Magma is unwarranted. The paleo evidence has been examined for nearly 40 years – since 1978 at least as referenced in the paper. That Climate Science has refused to recognize the validity of the proxies, or been ignorant of the previous studies, is what is being shown by this paper. They continue to use current GCMs as if they were not broken, and compare them to valid proxies, in order to make the point that their hypothesis is still correct and the models are valid. At the same time they refuse to recognize the evidence that, in the past, CO2 levels followed warming, not the other way around, so, IMO, their hypothesis about CO2 forcing is wrong and this is the basis of what is wrong with the models.

  47. Alan Robertson says:

    Mike Tremblay says:
    March 24, 2014 at 8:42 am

    Magma says:
    March 24, 2014 at 7:11 am
    Alan Robertson says:
    March 24, 2014 at 7:18 am
    ——————————————–
    Magma is correct… This paper seems more to be an exercise in showing that the models are valid because they correspond with what the proxies are showing.
    _______________________
    Howdy Mike,
    I agree with your assessment of this paper. Perhaps I misinterpreted what Magma was saying. Maybe he’ll come back and clarify his remarks.

  48. Gary Pearse says:

    “speculate that this instability may be linked to dual stability modes of the Arctic sea ice cover characterized by e.g. transitions between periods with and without perennial sea ice cover.”

    Oh Lord, bring them back to earth. I wonder if they have looked at a paper that has direct OBSERVATIONS of the lack of sea ice during the Holocene Climate Optimum!! Yes observations. How is this possible:

    http://wattsupwiththat.com/2010/09/08/inconvenient-ice-study-less-ice-in-the-arctic-ocean-6000-7000-years-ago/

    This study shows what you can do on a modest budget. They studied the beaches on the north coast of Greenland which these days is perennially bound in ice – even with our “alarming” summer extents and thicknesses that are to doom the planet. It is a classic. They looked at the raised beaches – higher sea levels (not much crustal rebound on Greenland), the plow marks made by ancient broken ice pack pushed onshore by wind, the beach itself which requires a good stretch of ocean with wind to build them and….wait for it… driftwood and other organic material that can be dated. Elegant and refreshing.

  49. Adrian Metcalfe says:

    Reporting this research here is just another dog whistle to those for whom the political implications of AGW mean it can’t be true. Either that or they’re too stupid to understand that just because the Polar ice cap melted 6000 years ago when it was closer to the sun means it can’t also melt now because of the effect of greenhouse gases.

  50. Duster says:

    jamesibbotson says:
    March 24, 2014 at 5:37 am

    If increased insolation caused reduced ice in the past, whi do they assume its GHG levels in the present.

    The graph is the explanation. According to that, the present annual mean insolation north of 80 degrees is lower than it was 16,000 years ago.

  51. Alan Robertson says:

    Adrian Metcalfe says:
    March 24, 2014 at 9:24 am

    Reporting this research here is just another dog whistle to those for whom the political implications of AGW mean it can’t be true. Either that or they’re too stupid to understand that just because the Polar ice cap melted 6000 years ago when it was closer to the sun means it can’t also melt now because of the effect of greenhouse gases.
    ____________________
    Why don’t you smarten us up? When do you predict the Polar Ice caps will melt? How about those predictions about Arctic ice melt? Were you one of the smarter- than- everyone- else guys telling us that the Arctic would be ice free by 2013? Does Antarctic sea ice increase count?

  52. Joe Ryan says:

    jamesibbotson says:
    March 24, 2014 at 5:37 am
    If increased insolation caused reduced ice in the past, whi do they assume its GHG levels in the present.
    ARGHHHHHHHH
    >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

    Funding concerns, I am sure.

  53. evanmjones says:

    Yeah, I pointed out that post-1998 “data rewrite” earlier. I see I wasn’t the only one who noticed!

  54. Adrian Metcalfe says:

    Alan Robertson says:

    “Why don’t you smarten us up? When do you predict the Polar Ice caps will melt? How about those predictions about Arctic ice melt? Were you one of the smarter- than- everyone- else guys telling us that the Arctic would be ice free by 2013? Does Antarctic sea ice increase count?”

    So, you deny that the current Arctic melt is due to greenhouse gases. How about publishing your peer reviewed research on what you’ve discovered is causing it?

  55. milodonharlani says:

    Adrian Metcalfe says:
    March 24, 2014 at 9:24 am

    Please state your evidence for earth being closer to the sun 6000 years ago.

    Unfortunately for the CACA faithful, Arctic sea ice extent is greater now than for most of the Holocene & perhaps all of the previous interglacial, the Eemian. Arctic sea ice virtually disappeared every summer not just 6000 years ago, but during the whole interval of the Holocene Climatic Optimum (except for the 8200 years ago cooling event) & then again during the peaks of the Egyptian, Minoan, Roman & Medieval Warm Periods. For at least 8500 of the past 10,000 years, arctic sea ice has been less, usually much less, than now.

    If modern warming & melting is “unprecedented”, it’s because of the greater than usual rather than less than usual summer sea ice coverage at both poles. Arctic sea ice was similar to now during the first half of the 20th century, too. Antarctic sea ice has probably not been as extensive as now since the depths of the Little Ice Age of c. AD 1700.

  56. milodonharlani says:

    Adrian Metcalfe says:
    March 24, 2014 at 11:48 am

    There is no evidence whatsoever that GHGs are causing Arctic sea ice to melt. If that were the case, then Antarctic sea ice would also be shrinking instead of growing, but it isn’t. Instead it is setting records for extent during the satellite era, ie since 1979. If increased global air temperature from the GHE were the cause of Arctic ice fluctuations, then both poles should be melting. Land ice is also growing on Antarctica. It stopped shrinking about 3000 years ago.

    Ocean currents are the major influence on sea ice extent, not minor air temperature fluctuations. Soot might however be causing surface melt pools on Arctic ice as well.

    Arctic sea ice is still well within normal natural limits. It shrank during the 1920s-40s, too, before satellites were around to measure it. And, as above, it went away every summer during the Holocene Climatic Optimum & subsequent warm periods. Its present behavior is nothing new & thus is affected little to not at all by CO2 increases.

  57. Larry Kirk says:

    This correlates well with evidence for 7mya to present (falling) Holocene sea levels evident here on the coast of Western Australia, much of it described here, in this excellent but possibly now hard to obtain Geological Survey of Western Australia publication:

    http://www.fishpond.com.au/Books/Geology-and-Landforms-of-Perth-Region-Bob-Gozzard/9781741680720

    Probably best sourced direct from GSWA:

    http://www2.dmp.wa.gov.au/ebookshop/searchMain.asp

    The section describing the detailed carbon dating (from driftwood) and morphology of the post-Holocene optimum coastal advance at the Rockingham-Becher Plain coastal is fascinating, as are the many instances of early Holocene-aged raised beaches, cliff-notches, etc. 2 to 4m above the present sea level (along this ocean coastline of a long-established, tectonically-stable and tectonically-remote continental margin, where such features are far less suspect than say the tectonically-active and recently ice-covered coastlines of northern Europe)

  58. Jimbo says:

    You can add these too.

    Abstract
    We therefore conclude that for a priod in the Early Holocene, probably for a millenium or more, the Arctic Ocean was free of sea ice at least for shorter periods in the summer. This may serve as an analogue to the predicted “greenhouse situation” expected to appear within our century.
    http://adsabs.harvard.edu/abs/2007AGUFMPP11A0203F

    Abstract
    Arctic sea ice cover was strongly reduced during most of the early Holocene and there appear to have been periods of ice free summers in the central Arctic Ocean. This has important consequences for our understanding of the recent trend of declining sea ice, and calls for further research on causal links between Arctic climate and sea ice.
    http://www.sciencedirect.com/science/article/pii/S0277379110003185

    Abstract
    Calcareous nannofossils from approximately the past 7000 yr of the Holocene and from oxygen isotope stage 5 are present at 39 analyzed sites in the central Arctic Ocean. This indicates partly ice-free conditions during at least some summers. The depth of Holocene sediments in the Nansen basin is about 20 cm, or more where influenced by turbidites.
    http://geology.geoscienceworld.org/content/21/3/227.abstract

    Abstract
    ….Nevertheless, episodes of considerably reduced sea ice or even seasonally ice-free conditions occurred during warmer periods linked to orbital variations. The last low-ice event related to orbital forcing (high insolation) was in the early Holocene,…
    dx.doi.org/10.1016/j.quascirev.2010.02.010

  59. Jimbo says:

    Gary says:
    March 24, 2014 at 5:52 am

    It’s 99% modeling results with a tiny bit of support from other studies using paleo data, some of which the authors say is contradictory. The only thing worthwhile coming from it is that models can cut both ways, which hardly supports the paper’s conclusion.

    See these studies which don’t rely on modelling.
    http://wattsupwiththat.com/2014/03/24/new-study-shows-arctic-sea-ice-extent-6000-years-ago-was-much-less-than-today/#comment-1597538

  60. Jimbo says:

    Magma says:
    March 24, 2014 at 7:11 am

    I am aware of the isolation issue. Now take a look at this close shave.

    Abstract
    The Early Twentieth-Century Warming in the Arctic—A Possible Mechanism

    The huge warming of the Arctic that started in the early 1920s and lasted for almost two decades is one of the most spectacular climate events of the twentieth century. During the peak period 1930–40, the annually averaged temperature anomaly for the area 60°–90°N amounted to some 1.7°C…..
    dx.doi.org/10.1175/1520-0442(2004)017%3C4045:TETWIT%3E2.0.CO;2

    Abstract
    The regime shift of the 1920s and 1930s in the North Atlantic

    During the 1920s and 1930s, there was a dramatic warming of the northern North Atlantic Ocean. Warmer-than-normal sea temperatures, reduced sea ice conditions and enhanced Atlantic inflow in northern regions continued through to the 1950s and 1960s, with the timing of the decline to colder temperatures varying with location. Ecosystem changes associated with the warm period included a general northward movement of fish……
    dx.doi.org/10.1016/j.pocean.2006.02.011

    Abstract
    Early 20th century Arctic warming in upper-air data
    Between around 1915 and 1945, Arctic surface air temperatures increased by about 1.8°C. Understanding this rapid warming, its possible feedbacks and underlying causes, is vital in order to better asses the current and future climate changes in the Arctic.
    http://meetings.copernicus.org/www.cosis.net/abstracts/EGU2007/04015/EGU2007-J-04015.pdf

    Monthly Weather Review October 10, 1922.
    The Arctic seems to be warming up. Reports from fishermen, seal hunters, and explores who sail the seas about Spitsbergen and the eastern Arctic, all point to a radical change in climatic conditions, and hitherto unheard-of high temperatures in that part of the earth’s surface….

    In August, 1922, the Norwegian Department of Commerce sent an expedition to Spitsbergen and Bear Island under Dr. Adolf Hoel, lecturer on geology at the University of Christiania. The oceanographic observations (reported that) Ice conditions were exceptional. In fact, so little ice has never before been noted. The expedition all but established a record, sailing as far north as 81o 29′ in ice-free water. This is the farthest north ever reached with modern oceanographic apparatus…..”
    docs.lib.noaa.gov/rescue/mwr/050/mwr-050-11-0589a.pdf

    Examiner (Launceston, Tas. – 25 April 1939
    …It has been noted that year by year, for the past two decades, the fringe of the Polar icepack has been creeping northward in the Barents Sea. As compared with the year 1900, the total ice surface of this body of water has decreased by twenty per cent. Various expeditions have discovered that warmth-loving species of fish have migrated in great shoals to waters farther north than they had ever been seen before….
    http://tinyurl.com/aak64qf

    IPCC – AR4
    Average arctic temperatures increased at almost twice the global average rate in the past 100 years. Arctic temperatures have high decadal variability, and a warm period was also observed from 1925 to 1945.
    http://www.ipcc.ch/publications_and_data/ar4/wg1/en/spmsspm-direct-observations.html

  61. Jimbo says:

    Steven Mosher says:
    March 24, 2014 at 8:06 am

    who believes models

    See these non-model ice free Arctic ocean papers.
    http://wattsupwiththat.com/2014/03/24/new-study-shows-arctic-sea-ice-extent-6000-years-ago-was-much-less-than-today/#comment-1597538

  62. Alan Robertson says:

    Adrian Metcalfe says:
    March 24, 2014 at 11:48 am

    “So, you deny that the current Arctic melt is due to greenhouse gases. How about publishing your peer reviewed research on what you’ve discovered is causing it?”
    ___________________
    Mwahahaaa
    I “deny” ever seeing so many logical fallacies packed into a mere two sentences, as you have done.

  63. milodonharlani says:

    J. Philip Peterson says:
    March 24, 2014 at 1:29 pm

    If that’s for real, then the return of the sun with onset of spring had more dramatic results than usual.

  64. Alan Robertson says:

    J. Philip Peterson says:
    March 24, 2014 at 1:29 pm

    OK, who’s melting the ice!!!?:
    http://arctic-roos.org/observations/satellite-data/sea-ice/observation_images/ssmi1_ice_area.png
    _____________________
    In past, sharp drops (as shown by NORSEX- your link) have usually indicated instrument issues. JAXA shows a lesser drop nd DMI barely registers a drop. There could be another large Arctic cyclone in play, but total area is still w/in 2 stndrd devs. of the 30 yr. avg.

  65. Bruce Cobb says:

    J. Philip Peterson says:
    March 24, 2014 at 1:29 pm

    OK, who’s melting the ice!!!?:
    http://arctic-roos.org/observations/satellite-data/sea-ice/observation_images/ssmi1_ice_area.png

    Good question! Anyone seen Al Gore lately?

  66. phlogiston says:

    Magma, jai mitchell

    The Arctic ice is not gone yet. Plus it was just as low a hundred years ago.

  67. Randy says:

    joe says:
    March 24, 2014 at 8:39 am

    Actually a study recently proved this is NOT likely to happen from the frozen tundra recently. They actually warmed up the land over years, as might simulate climatic change. The methane was simply not released from the soil as ASSUMED. So this part of the methane bubble claim is NOT supported by the closest thing to real world data we have. It is very telling how the field still relies on old assumptions in light of this.
    https://www.sciencenews.org/article/warming-may-not-release-arctic-carbon

    It is VERY telling if you pop keywords related to this into a search engine. you will find hordes of claims about how big of a timebomb the tundra soils stored carbon is. You will have to really look if you want to see the only study that actually TESTED the claims, and literally heated up the soil over decades, and found the long time claims false. Meanwhile all these sources claiming to be pushing the latest science, or climate facts and variation sof such memes somehow missed the most comprehensive data we have on the subject….

  68. phlogiston says:

    So an Arctic ice free in summer is an attractor. But if getting it that way via a warm gulf stream requires too much heat piracy from the SH with the Caribbean current, the ensuing and reciprocal Antarctic cooling could destabilise the system leading to a bipolar seesaw of growing magnitude, a signature of both the start and end of an interglacial (e.g. Tzedakis).

  69. milodonharlani says:

    jai mitchell says:
    March 24, 2014 at 8:46 am

    During the Holocene Climatic Optimum, Arctic sea ice extent was much lower than now, not the same.

    During HCO summers, Arctic sea ice virtually disappeared. Yet the polar bears survived. Indeed thrived.

  70. goldminor says:

    Alan Robertson says:
    March 24, 2014 at 7:18 am

    Magma says:
    March 24, 2014 at 7:11 am
    —————————————-
    @ Alan…I think you were correct with your remark regarding Magma. For some reason he assumes that everyone reading this has overlooked or forgotten about the insolation changes. Then as you point out, he has nothing to add to further anyone,s understanding of why the Arctic is being impacted in recent decades.

  71. Richard M says:

    J. Philip Peterson says:
    March 24, 2014 at 1:29 pm
    OK, who’s melting the ice!!!?:

    It’s not melting if you took the time to look at any of the satellite pictures (one of them shows an a missing area). Clearly, this is an instrument (or software) problem. It will disappear shortly.

  72. Ulric Lyons says:

    jauntycyclist says:
    “ulric -nice contextualising pic.
    i think if people still looking for eloquent images [a previous thread] showing global temps and where we are then yours sums it up.”

    No it does not, Greenland temp’ moves in opposition to the Temperate Zone through the Holocene.
    http://snag.gy/BztF1.jpg

  73. goldminor says:

    Alan Robertson says:
    March 24, 2014 at 1:44 pm

    J. Philip Peterson says:
    March 24, 2014 at 1:29 pm

    OK, who’s melting the ice!!!?:
    ————————————————
    Looking at NSIDC, JAXA, and the DMI it can be seen that in the last 2 days there has been a small downward shift in the trend. This small downturn comes after a sharp upward trend that lasted for 2 weeks. The sea ice had dipped below -2sd for 2 days before it then turned and almost made it to the 2000s trend line. This is similar top what the sea ice did in 2011/12. In the 3rd week of February 2012 at mid moon, the Arctic sea ice started a sharp upward movement. Right at the mid moon on the 8th of this month, the Arctic sea ice took a sharp upward turn. NSIDC shows the current spot sits in the middle of the -2sd trend.

    Antarctic sea ice is on the upswing again and is close to the +2sd line. the trend will likely cross above the +2sd line within 2 weeks.

  74. climateace says:

    ‘ wws says:
    March 24, 2014 at 7:20 am

    “other real scientists in my home country of Somerset discovered that the lake-village dwellers ate Pelicans for breakfast (European birds now found only in Greece and the Danube delta)!”

    I take it that there is a difference between a real scientist and a Skeptic Memer who abuses a fact or two about pelicans in order to make a spurious, non-scientific point about climate.

    Just for the record, Louisiana and the rest of the Gulf Coast are lousy with those things.’

    They are different species from the species wws is referring too, but the two north american pelican species are indeed doing well.

    It would be difficult to argue that pelicans have become extinct in Britain because of climate. The Dalmatian Pelican (fossils of which have been found in GB) still occurs as a vagrant in northern europe. Various species of pelicans occur naturally in climates similar to those of Britain. Various species of pelicans are found in captivity in London Parks where they sometimes do nasty things to pigeons – like catching them and swallowing them alive:

    As with other local, national and regional (as opposed to global) extinctions of various pelican species, the most likely recent extinction drivers are human activities: in the case of GB, 64 million people crowded into in a country that can no longer feed itself but has to import around three month’s worth of food annually. My guess is that the most likely factor is that pelicans have a tendency to abandon eggs or nestlings if disturbed.

    Most of the world’s eight pelican species have a sound conservation status.

  75. bushbunny says:

    The arctic or rather North pole is sea ice. It comes and goes, and it has reduced sunlight in winter and longer days in their summer. The Arctic circle has varying degrees of the same. But the Antarctic it has a land mass as well as fluctuating sea ice.

  76. When trees grow on the Arctic coastline ….. you know it had to be warm, to wit:
    ——————

    Holocene Treeline History and Climate Change Across Northern Eurasia

    Radiocarbon-dated macrofossils are used to document Holocene treeline history across northern Russia (including Siberia). Boreal forest development in this region commenced by 10,000 yr B.P.

    Over most of Russia, forest advanced to or near the current arctic coastline between 9000 and 7000 yr B.P. and retreated to its present position by between 4000 and 3000 yr B.P. Forest establishment and retreat was roughly synchronous across most of northern Russia. Treeline advance on the Kola Peninsula, however, appears to have occurred later than in other regions.

    During the period of maximum forest extension, the mean July temperatures along the northern coastline of Russia may have been 2.5° to 7.0°C warmer than modern. The development of forest and expansion of treeline likely reflects a number of complimentary environmental conditions,

    Read abstract @ http://www.sciencedirect.com/science/article/pii/S0033589499921233

  77. bushbunny says:

    I recall an article written by the captain of the first American nuclear submarine, I think it was in the late sixties. There were few places under the ice they could surface. Does anyone remember. Look what happened to those twits recently it happens in the Antarctic too.

  78. milodonharlani says:

    Samuel C Cogar says:
    March 25, 2014 at 10:31 am

    IOW, no catastrophic consequences of 2.5 to 7.0 degrees warmer than now. Maybe a little higher sea level, but easily adapted to. And the benefits would outweigh whatever problems might arise.

    Take the first C for Catastrophic out of CACA & no worries. Even fewer without the first A for Anthropogenic, meaning no basis for the second A for Alarmism. You’re just left with Climate (which always changes).

  79. milodonharlani says:

    goldminor says:
    March 24, 2014 at 5:40 pm

    JAXA not so alarming:

    http://www.ijis.iarc.uaf.edu/en/home/seaice_extent.htm

  80. bushbunny says:

    There was a team that visited Antarctica some years ago, and their research revealed prehistoric animal bones. Well that was before the continents separated and the poles appeared. They said this proved climate change did happen. I wonder how much they were paid to produce that bit of news. LOL

  81. philjourdan says:

    @bushbunny – They HAD to have been paid by the US government. The stupidity of their studies is world renowned. ;-)

  82. bushbunny says:

    Actually phil they were not American they were Danish I think. But my cousin sent me pics of a venture from the University of Cambridge, he is in the Irish Navy, (not Royal Navy) he was on the ship anyway. They anchored at some base and showed pics of floating sea ice bergs. Climate change obviously he recalled to his mum. She sent me the pics but I sent them back to keep themselves. I don’t think they were hired by the Americans? They would have picked a better boat for starters.

  83. goldminor says:

    goldminor says:
    March 24, 2014 at 5:40 pm
    Antarctic sea ice is on the upswing again and is close to the +2sd line. the trend will likely cross above the +2sd line within 2 weeks.
    ———————————————-
    Antarctic sea ice just went above the +2 sd line. That only took one week. The steeper angle in the trend is noticeable. The regrowth should be rapid this year.

  84. bushbunny says:

    I recall seeing the documentary taken by an Australian of one antarctic expedition by Sir Ernest Shackleton when their ship was eventually crushed by the pack ice in Antarctica. There forward of the silent black and white movie said the Antarctic controls the climate with its converging ocean currents and ice coverage. Being mainly a large land mass as well as sea ice. Don’t you remember at school, they had us repeat in rote the continents? Ending up with the Arctic is not a continent. But Antarctica is. If 12 year olds know this why these dumb asses ignoring sea ice comes and goes.

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