Inconvenient study: Arctic was warmer than the present during the Medieval Warm Period

New paper finds temperatures were as much as 0.5c warmer in the Arctic during the MWP than today.

The Hockeyschtick reports: A paper published yesterday in Global and Planetary Change reconstructs temperatures in Northern Fennoscandia [within the Arctic circle] over the past 1,600 years and finds more non-hockey-sticks clearly demonstrating that the Arctic was warmer than the present during the Medieval Warm Period. The paper adds to over 1,000 peer-reviewed published non-hockey-sticks finding the Medieval Warm Period was global, as warm or warmer than the present, and that there is nothing unusual, unnatural, or unprecedented about the current warm period.

Furthermore, the authors find a natural 70-80 year oscillation of temperatures, similar to the 60-70 year oscillation of the natural Pacific Decadal Oscillation [PDO].


So much for “Arctic amplification.”

All four of these temperature reconstructions show the Medieval Warm Period ~1000 years ago was warmer than the present [year 2000].

Fig. 1. Different estimates of Northern Fennoscandian temperature anomalies between 400-2000 AD. Shown are the present conventional estimate (Ttorn, green) which is rather close to that in Grudd08, the present filtered estimate (Tlong, blue), smoothed temperatures of Esper12 (Tesp, red) and smoothed August SST reconstruction from the Norwegian Sea (black).

Fig. 3. August SST [sea surface temperature] reconstructions from the south of Iceland (above, blue) and the Norwegian Sea (below, blue) (modified from Miettinen et al., 2012). Red solid lines show smoothed values.

The new temperature reconstruction presented by this paper shows the Medieval Warm Period [~1000 years ago] in the Arctic was warmer than the present [year 2000] temperatures.

Fig. 4. The present estimate of the climatic temperature anomalies (red, Tclim = Tesp + Tsea + Tvolc), and Tesp from Fig. 1 (thick blue).

The paper: http://www.sciencedirect.com/science/article/pii/S0921818114000253?np=y

A 70-80 year peridiocity identified from tree ring temperatures AD 550 – 1980 in Northern Scandinavia

Juhani Rinne, Mikko Alestalo, Arto Miettinen

Highlights

• Volcanism and millennial variations
• Decadal (volcanic) variations
• Multidecadal (oceanic) variations
• Climate variations as seen in tree-ring temperatures
• Biases in the Torneträsk paleotemperatures

Abstract

The classical Maximum Density data of 65 Torneträsk trees from years 441-1980 AD are studied in millennial, centennial and volcanic scales. The millennial scale is analyzed applying a specific filtering method. In that scale, the climate is cool after 1200-1400 AD. This more or less steady period is suggested to be due to volcanic episodes, which reduced the northward heat transport in the North Atlantic. The century scale variation, on the other hand, is suggested to be due to [natural] internal oscillations in sea surface temperature (SST) and to be connected to variations in the Arctic sea ice. Specifically, these oscillations have caused an additional warming and cooling trend in Northern Fennoscandian temperatures before and after 1930’s, respectively.

Variations in the temperature estimates are explained by the results for different temporal scales. All of them show local impacts leading to differences when compared with hemispheric estimates. The long-term estimate of the temperature as derived from the present Torneträsk data is found to be biased. The source of that is unknown.

Source: The Hockeyshtick

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85 thoughts on “Inconvenient study: Arctic was warmer than the present during the Medieval Warm Period

  1. burn them!!! heretics….burn them all…..oh wait, we can’t burn them, think of the CO2. Can we smother them instead?

  2. Actually Northern Scandinavia isn’t in the Arctic even though it’s partly north of the Arctic Circle. Subarctic perhaps, but not arctic.
    And yes, it has long been known that the climate was significantly warmer during the MWP, as shown by remains of trees well above the current treeline. The treeline data indicate temperatures 0.6-0.8 degrees warmer than at present for a period long enough for pine-trees to mature.

  3. Ever notice how everyone uses “tree rings” only when those rings tell them what they wish to see? Gotta’ “filter” those babies. Otherwise, they’re all over the map. Just sayin’.

  4. Abstract: The classical Maximum Density data of 65 Torneträsk trees from years 441-1980 AD are studied in millennial, centennial and volcanic scales.

    Only 65 trees?
    Well at least they cover a long time period.
    But I would really like another proxy to calibrate the tree rings against. Tree rings are affected by so many factors.
    Confession: I haven’t read beyond the abstract

  5. The idea that some may have tried to “erase the MWP” may not be something that can be proven by an actual document, but it sure does seem like papers like this one were, if not suppressed, never given any press, (and likely given little funding for follow-up studies.)

    The problem is that the MWP was real, and was warmer, and therefore any honest study will find evidence of the truth. Attempting to “erase” such a truth is like attempting to put out a fire by stamping sparks on the floor, when it is the ceiling that is burning.

    The Greenland Vikings, at the height of their prosperity, were raising 2000 cows and 100,000 sheep and goats in a single district of their colony. They couldn’t import fodder for the long winters and had no electronic devises for keeping the animal’s drinking water unfrozen. To imagine conditions were anything like current conditions is the imagination of a complete dunderhead.

    What is really amazing about those Greenland Vikings is that they hung on so long after it got cold. For the final hundred years it makes no sense. Their economy likely involved some element we don’t know about, (and which they didn’t tell Europe about.) It’s a wonderful mystery still waiting to be solved.

  6. The cool period: volcanoes or the sun, or both?
    Solar activity should be mentioned as a major factor.

  7. Your average warmist alarmist will come back with, “Yah, but this was only a regional warming. The actual global temperature was far lower than it is today.”
    Remember, it is the church of the warmist alarmists we are dealing with.

  8. I doubt if there was anything special about the recent “Modern Warm Period.” I’m waiting for Charvatova’s 2,400 year major cycle to be refuted, but if it isn’t then we have one more Jose cycle (179 years) to go before the next real 300 year long “Warm Period.” Meanwhile, we shovel snow.

  9. My problems with how this is reported:

    1. The name of the paper and its authors should be in the first paragraph, not at the end of the article. It’s A 70-80 year peridiocity identified from tree ring temperatures AD 550 – 1980 in Northern Scandinavia by Juhani Rinne, Mikko Alestalo, Arto Miettinen. The title already tells us two things.
    2. Northern Scandinavia gets extrapolated to ‘the Arctic’.
    3. What has happened to temperatures in Northern Scandinavia after 1980? I believe it is said that global warming proceeds about 4 times as fast as globally at those latitudes. Can HockeySchtick or Anthony Watts please provide a graph?

    For instance, I have found September average for Tromsø here. The graph is difficult to eyeball because of the small Y-axis, but to me it looks like on average Tromsø has warmed over 2 °C in September since 1980.

  10. Very long ago, my journey to skepticism began when a global warming scare article slipped up by mentioning, in passing, the amount that sea levels were higher than present during the MWP (which seemed rather curious for a supposedly small regional event and sparked further investigation).

    While this Rinne et al. paper’s primary attribution of the temperature history would be a separate topic, the shape of their arctic temperature histories in figure 1 (aside from the green one which is weird) look somewhat like multi-proxy estimates (including non-tree-ring) from other sources for history of the overall Northern Hemisphere average, as in versus a plot 3/4ths of the way down in http://img103.imagevenue.com/img.php?image=28747_expanded_overview3_122_966lo.jpg .

    (Based on other data, generally the Northern Hemisphere temperature average tends to follow a pattern historically rather similar to the arctic, albeit with the arctic warming/cooling more in quantitative terms).

    With that said, if comparing to another plot in the prior link, for the double peak of arctic temperature history over the 20th century, something is weird with the magnitude of the temperature scale in the Rinne et al. paper’s plots, as they start to show that double peak but at far smaller a fraction of a degree Celsius.

    Probably part of what may be going on is from the Rinne et al. usage of a tree ring proxy reconstruction, with tree rings of some utility but rather imperfect.

    The Rinne et al. paper source given is just a version paywalled aside from the abstract and plots, though, so evaluating it would take more anyway.

  11. It’s interesting to see that the Wolf (1280~1350), Sporer (1450~1550), Maunder (1645~1715) and Dalton (1790~1820) Grand Solar Minima correspond precisely with cold Periods shown in fig. 4 of this paper…

    Since there seems to be growing evidence the Sun could be entering another Grand Solar Minimum (GSM) from 2020, this will be yet another nail in the coffin of the CAGW hypothesis as we’d likely experience an extended cool period.

    If we do suffer through another GSM, ironically, the added CO2 will improve crop yields to help offset some of the effects of shorter growing seasons, and the tiny 0.25C~0.5C of plausible AGW would actually lessen the negative effects of a GSM….

    Oh, the irony of it all… Rising CO2 levels may actually end up saving millions from famine and exposure….

  12. Mike – It’s still a hockey stick…if you hold it just right
    It looks like a hockey stick after a stiff cross check snapped in the middle. Usually results in a major penalty if you break the stick

  13. Yes, at the start of the 20th Century a Norwegian chap called Roald Amundsen decided, in the name of scientific exploration, to chase a “fable”. The fable was that in the days of old it was possible to cut the journey to “Vinland” (Now North America) short by sailing through the waters to the North West of Greenland, which at certain times would be open to shipping. In 1903 he managed to do just that, but it took a long time and it was realized that the North West waters was not as warm then as they must have been in the past. But at least he had proved that the “Fable” was likely to have its roots in real history. Could these “roots” belong in the Medieval Warm Period?

    By the way, it may be interesting, to some of us, that at and around the year 1903 there was a “Solar Minimum” a bit akin to the one we are experiencing now. What the “Jet Stream” or Polar Vortex was doing then I do not know, nor do I know what kind of activity was taking place at the “Sea Floor” way up there in the Arctic Ocean. – In other words; – “Was there high, or was there low volcanic sea floor activity? –

    “Volcanic Sea Floor Activity” (VSFA) in the Arctic Ocean is likely to have been fairly high lately as the Volcanoes and Geysers on Iceland have been, as far as I know, quite busy. — Or busy enough to ground a large part of the world’s Air Traffic (AT)

  14. SAMURAI:

    With regard to your prior post, potentially you might find the following of interest (where a plot since 800 A.D. is in it, not at the top but a ways down), the same link as in my earlier comment except the slightly newer version I meant to post:

  15. Sorry, it’s not exactly a peer reviewed paper but the weight of evidence involving blatant cherry-picking, abnormally large and inexplicable weighting given to the flawed ‘warming biased’ bristlecone pine data makes it obvious that it was intentional. Not to mention the program used created a hockeystick even with red noise input.

  16. Mikko Alestalo is Director of FMI Finnish meteorolocigal institute and has been wery active warmist with AGW group. Is this study some backdoor and is there going to come some more? Is their seats so hot allready?

  17. Ahhhh those were the days.
    H.H. Lamb1965
    The early medieval warm epoch and its sequel

    The Arctic pack ice was so much less extensive than in recent times that appearances of drift ice near Iceland and Greenland south of 70[deg] N, were apparently rare in the 10th century and unknown between 1020 and 1194, when a rapid increase of frequency caused a permanent change of shipping routes. Brooks suggested that the Arctic Ocean became ice-free in the summers of this epoch, as in the Climatic Optimum; but it seems more probable that there was some ‘permanent’ ice, limited to areas north of 80[deg] N….”
    Elsevier Publishing Company
    Palaeogeography, Palaeoclimatology, Palaeoecology, 1:1965, p. 15-16

    Variations In Climate
    Press, Volume XLIV, Issue 6903, 8 November 1887, Page 6
    By Alexander Beck, M.E.
    “…The reverse of that state of things is found by calculations for the year 1122 A.D., and it is precisely at that time that we find the Danes and several Scandinavian nations going through the Arctic open seas. Colonies are established by them in the highest north latitude of Greenland, and upper part of North America, a long time before Christoper Columbus had reached a more southern part of the same continent….”

    http://paperspast.natlib.govt.nz/cgi-bin/paperspast?a=d&cl=search&d=CHP18871108.2.35&srpos=133&e=——-100–101—-0glaciers+melting

    Abstract
    Micheal Mann et. al.
    The 15th century Arctic warming in coupled model simulations with data assimilation

    … Available observational data, proxy-based reconstructions and our model results suggest that the Arctic climate is characterized by substantial variations in surface temperature over the past millennium. Though the most recent decades are likely to be the warmest of the past millennium, we find evidence for substantial past warming episodes in the Arctic. In particular, our model reconstructions show a prominent warm event during the period 1470–1520. This warm period is likely related to the internal variability of the climate system,….
    doi:10.5194/cp-5-389-2009

    I wonder whether there are any colonies established in the highest north latitude of Greenland today? Coming up next is our tree lines.

  18. Claude Harvey
    January 28, 2014 at 6:29 am
    says:
    ‘Ever notice how everyone uses “tree rings” only when those rings tell them what they wish to see? Gotta’ “filter” those babies. Otherwise, they’re all over the map. Just sayin’.’

    Aw, c’mon. At least the Tornetrask (sorry about the missing dots over the ‘a’ – I’m on an i-Phone) trees are in the Arctic Circle. Last time I checked California and Nevada weren’t. But then again, you may have a point.

    “Mommy, Michael pulled my hair and took my trees!”
    “Mikey, give those trees back to Sarah. Now!”
    “I didn’t take Sarah’s trees.”
    “Mikey did too take my trees.”
    “I did not!”
    “You did too!”
    “I did not!”

    And thus was born Climate Science: another indication that humanity has a ways to go on its tenuous march towards maturity.

  19. SAMURAI says:
    January 28, 2014 at 7:29 am

    “Since there seems to be growing evidence the Sun could be entering another Grand Solar Minimum (GSM) from 2020…”

    Yes, and we have still another GSM to go through starting in 2,200 before we get to the next 300 year warm period starting in 2,400. We need to stop freaking about routine climate change.

  20. Gee, only 0.5C warmer? That is a record that will encourage desperate upward adjustments by a shell-shocked CAGW team. We can’t seem to get thermometers this accurate in the climate record. Also look at the swings in north of 80 temps (DMI) on the sea ice page. Anyway, there is abundant data in the form of history and other markers that the arctic has been warmer than today. How about driftwood and sandy beaches formed by wave action on the northernmost coast of Greenland that during our times is never free of ice.

    http://www.bitsofscience.org/arctic-sea-ice-holocene-2614/

  21. How is this “so much for arctic amplification”? It was warmer in the MWP and the arctic was warmer still.

  22. 1) Is tree ring proxy data in this region reliable?
    2) To what level of precision is the proxy known? Where is the error band?
    3) The average of the 4 plots make for a pretty broad swath.

  23. There is really nothing new here. Back in the early 1990s Jonathan Overpeck did a study in the same general area over the same period and had the same result. I’ll google it up later. That result made him ponder that the medieval warm period did not need to be global, denouncing it’s existence in the AGU 1997 fall meeting (I seem to remember)..

  24. Think about what you would argue if the results gave you the opposite answer

    1. treemometers are bogus
    2. pal review
    3. only 65 trees
    4. it only goes to 1980, update the proxies

    blah, blah blah.

    Bottom line. we have some evidence it was warmer in certain regions during the MWP,
    some evidence it wasn’t as warm. All in all the uncertainty is high across all types of uncertainty.

    real bottom line: MWP says nothing about ow much warming we will see.

  25. Here are some past tree lines.

    Abstract
    Climate change and the northern Russian treeline zone
    G.M MacDonald et al – 2007
    …..Dendroecological studies indicate enhanced conifer recruitment during the twentieth century. However, conifers have not yet recolonized many areas where trees were present during the Medieval Warm period (ca AD 800–1300) or the Holocene Thermal Maximum (HTM; ca 10 000–3000 years ago).

    http://rstb.royalsocietypublishing.org/content/363/1501/2283.short

    ———————————-
    Abstract
    Holocene Climate Reconstructions from the Fennoscandian Tree-Line Area Based on Pollen Data from Toskaljavri
    ….values during the “Medieval Warm Period” (ca. 1400–1000 cal yr B.P.) were ca. 0.8°C higher that at present but decreased rapidly to the low “Little Ice Age” levels at 800 cal yr B.P. We compare these results with an earlier pollen-based climate reconstruction from the same region…….

    http://www.sciencedirect.com/science/article/pii/S0033589401923130

    ———————————–
    Abstract
    Temperature patterns over the past eight centuries in Northern Fennoscandia inferred from sedimentary diatoms
    ……Establishing natural climate variability becomes particularly important in remote polar regions, especially when considering questions regarding higher than average warming. We present a high-resolution record of temperature variability for the past 800 yr based on sedimentary diatoms from a treeline lake in Finnish Lapland. The BSiZer multiscale smoothing technique is applied to the data to identify significant features in the record at different temporal levels. The overall reconstruction shows relatively large multi-centennial temperature variability with a total range of about 0.6–0.8°C. ……
    doi: dx.doi.org/10.1016/j.yqres.2006.01.005
    Quaternary Research – Volume 66, Issue 1, July 2006, Pages 78–86

    And one man’s tree rings against another Mann’s.

    Abstract
    Torneträsk tree-ring width and density ad 500–2004: a test of climatic sensitivity and a new 1500-year reconstruction of north Fennoscandian summers
    This paper presents updated tree-ring width (TRW) and maximum density (MXD) from Torneträsk in northern Sweden, now covering the period ad 500–2004. By including data from relatively young trees for the most recent period, a previously noted decline in recent MXD is eliminated. Non-climatological growth trends in the data are removed using Regional Curve Standardization (RCS), thus producing TRW and MXD chronologies with preserved low-frequency variability. The chronologies are calibrated using local and regional instrumental climate records. A bootstrapped response function analysis using regional climate data shows that tree growth is forced by April–August temperatures and that the regression weights for MXD are much stronger than for TRW. The robustness of the reconstruction equation is verified by independent temperature data and shows that 63–64% of the instrumental inter-annual variation is captured by the tree-ring data. This is a significant improvement compared to previously published reconstructions based on tree-ring data from Torneträsk. A divergence phenomenon around ad 1800, expressed as an increase in TRW that is not paralleled by temperature and MXD, is most likely an effect of major changes in the density of the pine population at this northern tree-line site. The bias introduced by this TRW phenomenon is assessed by producing a summer temperature reconstruction based on MXD exclusively. The new data show generally higher temperature estimates than previous reconstructions based on Torneträsk tree-ring data. The late-twentieth century, however, is not exceptionally warm in the new record: On decadal-to-centennial timescales, periods around ad 750, 1000, 1400, and 1750 were equally warm, or warmer. The 200-year long warm period centered on ad 1000 was significantly warmer than the late-twentieth century (p < 0.05) and is supported by other local and regional paleoclimate data. The new tree-ring evidence from Torneträsk suggests that this “Medieval Warm Period” in northern Fennoscandia was much warmer than previously recognized.
    10.1007/s00382-007-0358-2

  26. Paul Westhaver says:
    January 28, 2014 at 8:11 am

    1) Is tree ring proxy data in this region reliable?
    2) To what level of precision is the proxy known? Where is the error band?
    3) The average of the 4 plots make for a pretty broad swath.

    That’s why I prefer past tree lines, some of which I mention above.

    Here is another sign of the Medieval Warm Epoch in Alaska.

    An ancient forest has thawed from under a melting glacier in Alaska and is now exposed to the world for the first time in more than 1,000 years.
    …..A protective tomb of gravel likely encased the trees more than 1,000 years ago, when the glacier was advancing, Connor said, basing the date on radiocarbon ages of the newly revealed wood. As glaciers advance, Connor explained, they often emit summer meltwater streams that spew aprons of gravel beyond the glacier’s edge…….

    http://www.livescience.com/39819-ancient-forest-thaws.html

  27. NevenA:

    3. What has happened to temperatures in Northern Scandinavia after 1980? I believe it is said that global warming proceeds about 4 times as fast as globally at those latitudes. Can HockeySchtick or Anthony Watts please provide a graph?

    As this presentation about European Arctic temperatures in the past 100 years (including Greenland and Sodankylä in Finnish Lapland) concluded:

    Mann-Kendalls non-parametric test revealed that only a few series (from Iceland and northern Norway) show a statistically significant warming (5% level or better) from 1900 to 2002. Førland et al. (2002) actually concluded that none of the stations in Figure 1 showed a statistically significant warming from 1910-1999.

    http://acsys.npolar.no/meetings/final/abstracts/posters/Session_1/poster_s1_009.pdf

    You can check Sodankylä which has the longest continuous Lapland record (1908-2008) in Finland from NASA GISS:

    GISS Surface Temperature Analysis

    Station Data: Sodankyla (67.4 N,26.6 E

    As you can see, temperatures today are slightly higher than 1930-1950. Maybe 0.3 C. The reason for big “jump” in global warming is that the coldest period in 100 years was between 1965-1985. You draw a trend line from 1965 to 2010 and it looks like temps went up by 2 degrees C.

  28. Caleb says:

    “For the final hundred years it makes no sense. Their economy likely involved some element we don’t know about, (and which they didn’t tell Europe about.) It’s a wonderful mystery still waiting to be solved.”
    Viking economy was based for many years upon rape, pillage and looting. Monestaries were prime targets and anywhere there was a port, ocean or river or whatever, they showed up, took the gold and silver and left their genes behind. I have a short dark family tree with one great grandfather who was well over 6 feet tall with blond hair and light eyes and here and there in our family those traits pop up now and then. We have old photos (black and white of course) of him and his family, great-grandmother of Greek extraction, short and dark, great-grandfather tall and fair, small children as he was young in the picture so his hair was not grey or white but blond. Don’t know about the final 100 years as that of which I speak was the Vikings’ economy of 1000 or so years ago. Greenland was one of the few cases I know of where they stayed for very long. Maybe they just went back to their old practices.

  29. NevenA: . What has happened to temperatures in Northern Scandinavia after 1980? I believe it is said that global warming proceeds about 4 times as fast as globally at those latitudes. Can HockeySchtick or Anthony Watts please provide a graph?

    Just go to NASA GISS and put in station name or use this address:

    http://data.giss.nasa.gov/cgi-bin/gistemp/find_station.cgi?dt=1&ds=14&name=Sodankyla

    Click Sodankyla and you’ll get the data. It is the same story in European Arctic in the past 100 years: very little warming. 2000-2010 is maybe 0.3 C warmer compared to 1930-1950 period.

    But if you cherrypick and choose 1965 as your starting year, very impressive warming in order of 2 degrees C. 1965-1985 was the coldest period during the past 100 years in the European Arctic

  30. Jimbo says:

    “Ahhhh those were the days.
    “H.H. Lamb – 1965
    “The early medieval warm epoch and its sequel… I wonder whether there are any colonies established in the highest north latitude of Greenland today? Coming up next is our tree lines.”

    Thanks for that. Yes, the MWP was global and warmer than today. Those facts were completely uncontested prior to the “carbon”/global warming scare.

    ==========================

    Steven Mosher says:

    “MWP says nothing about (h)ow much warming we will see.”

    I beg to differ. The MWP occurred toward the tail end of the Holocene warming. Each peak was somewhat less warm than the previous peak. Therefore, it tells us that current and future warming cycles will probably be less warm.

    For those who haven’t seen it, this animation puts the current *mild* and natural global warming cycle into perspective. There is nothing either unusual or unprecedented in today’s climate. Catastrophic AGW is nothing but a massive head-fake, and AGW itself — if it exists — is only a tiny, insignificant forcing that should be completely disregarded when discussing national and international policy.

  31. @ Steve Mosher,
    The tree rings may or may not be telling us about the future climate, but taken as a whole, they show us that neither does the consensus view. And especially we should be able to agree that the models tell us about the same.

  32. dbstealey says:
    January 28, 2014 at 7:44 am
    “NevenA says:

    “Northern Scandinavia gets extrapolated to ‘the Arctic’.”

    Nothern Scandinavia is north of the Arctic circle:”

    For a definition of the Arctic, please look at the reference page Northern Regional Sea Ice Page at this blogs´masthead. Btw. it´s the Polar circle.

  33. The real bottom line — It was warmer in the past and the world didn’t come to an end. CO2 has also been higher in the past, BTW, and the world didn’t come to an end then, either. And just one more — the high CO2 periods and warm periods don’t always correspond.

    But the past tells us nothing about the future. Only models can tell us that.

    #heavy sarcasm

  34. Jim G says:
    January 28, 2014 at 9:39 am

    ‘Viking economy was based for many years upon rape, pillage and looting. Monestaries were prime targets and anywhere there was a port, ocean or river or whatever, they showed up, took the gold and silver and left their genes behind…. Don’t know about the final 100 years as that of which I speak was the Vikings’ economy of 1000 or so years ago. Greenland was one of the few cases I know of where they stayed for very long. Maybe they just went back to their old practices.’

    This is not remotely the case. Greenland settlement, like a lot of Scandinavian settlement all over Europe in this period, was fundamentally about getting and holding land, trading, farming, fishing and the exploitation of animal resources (furs, skins etc.), once the initial periods of conflict and raiding were over. These Vikings were ubiquitous traders and travellers all over Europe, modern western Russia, down to the Ukraine, the Byzantine empire and into Muslim lands, as well as fierce opponents to their more civilised neighbours if necessary. Some of them were liberty fans, moving to avoid the authoritarian rule of monarchs – as was the case in the initial settling of Iceland.

    The history of the ‘Vikings’ is far more about these factors, especially in relation to Greenland where there were no obvious targets for rape, pillage and worthwhile looting, and certainly no handy rich monasteries to sack. It’s just too far away and a very risky trip to make, either way. Violent neighbour disputes and feuds occurred perhaps (they are certainly common enough in Icelandic history) but not what you describe here.

    By the time the Greenlanders gave up they were all Christians anyway and presumably regarded the place as their home, however hard it was. Also, the climatic downturn didn’t just happen overnight and people will hang on if they can, adapting as they can to the changing conditions. It will have taken two or three generations for people to finally realise this wasn’t just a blip in the weather and that a decent life was no longer possible.

  35. Steven Mosher says at January 28, 2014 at 8:39 am

    Think about what you would argue if the results gave you the opposite answer
    1. treemometers are bogus
    2. pal review
    3. only 65 trees
    4. it only goes to 1980, update the proxies

    Look at my post near the top (January 28, 2014 at 6:41 am).
    I gave you 1 and 3.
    Point 4 isn’t important with respect to the MWP; that predates the 1980s.

    Why do you suspect point 2?

  36. This is astounding, authors of this study are from FMI, Finnish Meteorological Institute. This is like UK MetOffice would say, Oops, sorry about wiping MWP off the charts, here it is back, stronger than ever, even hotter than today. Mr Mann is going to have a bad hair day.

    a Finnish Meteorological Institute, P.O. Box 503, FI – 00101 Helsinki, FINLAND
    b Department of Geosciences and Geography, P.O. Box 64, FI – 00014 University of Helsinki FINLAND

  37. Quote “Furthermore, the authors find a natural 70-80 year oscillation of temperatures, similar to the 60-70 year oscillation of the natural PDO”.

    My funny thought: You have a 75 year cycle and a 65 yer cycle. How far are the peaks apart after 4 cycles?

  38. Clearly this is denialist lies as the authors have been seen to walk past gas stations without spitting on therm which ‘proves ‘ their in the pay of big oil.

  39. richard says: @ January 28, 2014 at 10:32 am

    http://www.spiegel.de/international/spiegel/the-coming-and-going-of-glaciers-a-new-alpine-melt-theory-a-357366.html

    >>>>>>>>>>>>>>>>
    He does a real nice fancy dance to CYA about Global Warming doesn’t he?

    …Joerin is quick to explain that he is not trying to explain away the effects of man-made warming of the past few years: “Our findings so far could also be seen as giving the exact opposite of a climatic all-clear,” he says. “If we can prove that there were ancient forests where the glaciers are today, it means one thing in particular: that the climate can change more suddenly than we thought.”

  40. CEH says:

    “For a definition of the Arctic, please look at the reference page Northern Regional Sea Ice Page at this blogs´masthead. Btw. it´s the Polar circle.”

    Where I went to school, it is called the Arctic Circle. Just as the map says: The area within the “Arctic Circle”.

    But YMMV.

  41. “1. treemometers are bogus … ”
    Forget the trees, thermometers record temperatures in the Arctic at least as warm as now seventy years ago, before human CO2 emissions could have been a factor.

  42. Steven Mosher says:

    “You need to up ur skepticism.”

    Another vague, cryptic, nebulous statement. Contrast it with my comment, which contained two (2) supporting links, and an unarguable [to me☺] real world example showing that the MWP was warm enough to support settlements in what was, until quite recently, frozen permafrost since the end of the MWP.

    I can post lots of peer reviewed papers and empirical evidence showing that the MWP was warmer than now. Others have done so, too. So I stand by my statement, and I don’t think you came close to refuting anything I wrote.

    Steven, you will need to do more than make baseless assertions to be convincing.

  43. Mosher’s right about treemometers. They’re about as good at revealing paleo-temperatures as tarot cards. Treemometer studies should be rejected by all serious climate students.

    Good call Mosh-pit. Even a blind squirrel finds an acorn once in a while.

  44. Dr. J.Curry is also looking into Arctic temperatures; I posted this comment
    Arctic temperature oscillations are out of phase with the N. Atlantic and N. Pacific, with the decadal periodicities (uniquely) close to those found in the oscillations in the Earth’s core.
    Inner core Oscillations 85 50 35 28 years
    Arctic spectrum 82 54 32 25 years
    This would suggest that role of the Earth’s magnetic field may be more important than previously assumed.

    http://www.vukcevic.talktalk.net/Arctic.htm

  45. All treemometers are not equal. The longest Finnish dendro data series covers 7600 year and was awarded as one of the best. It does not use the thickness of the rings to represent temperature.

    Instead they pull out big pine trunks from small ponds in Finnish Lapland where ponds are now surrounded by dwarf birch and there are not pines growing anywhere near. Today it’s too cold and pine dos not grow at that height any more.

    They use tree rings to date the trunks very accurately by syncing different trunks from different ages, and based on the altitude trunks were found determine temperature. Trunks have been preserved thousands of years in the muddy bottom of the pond, and low oxygen water.

    That’s accurate method, even if there is water or nutrients, pine does not grow if it’s too cold.

    Here’s their 7600 yr raw data:

    http://lustiag.pp.fi/data/Advance/Advance10K_t7ps2.xlsx

  46. Temperature of Scandinavia seem to follow AMO cycle and NAO. AMO is based on its 50–90 year quasi-cycle and this study show 70-80 year cycle averaged over 1600 year period. 70-80 year cycle fits well inside 50-90 year cycle of AMO, currently defined by much shorter sample.

    I would think that temperature and AMO are in sync for Scandinavia and NH.

  47. “A 70-80 year peridiocity identified from tree ring temperatures AD 550 – 1980 in Northern Scandinavia”

    I would like to see the actual spacing, I would be predicting four 69yr intervals followed by a 42yr interval making 318yrs (317.76), or three 69yr intervals followed by a 111yr interval, again 318yrs. The latter would give a predominance of 69yr steps but an apparent average of 79.5yrs.

  48. D. B. Stealey, unlike the no-evidence AGWers, you got game, man. They haven’t even found their way to the basketball pavilion and you are out their sinking 3-pointers. You go, Dave! It’s just like someone whose team is loooosing big time to tell someone on the other team to up their game, LOL (a BEST defense is a good offense, heh, heh).

    Man, I really want to LIKE Steven Mo-sher (I guess I kinda do or I wouldn’t even want to want to!). Why can’t he just give up the pretense?!
    ***********************************

    re: the NO-game AGWer bogus argument (Jim S at 7:25am today — good point, Jim S; below, I am not attacking you, I hope your realize): “The actual global temperature was far lower… .”

    The slam-dunk answer remains what it has always been (and, almost certainly, always will be):

    Prove it.

    They have NEVER done this.

    **********************************************************

    Note: @ AGWers –> there is no “global temperature.” Only temperatures. In the MWP, many of them (in the various climate zones) were higher than they were after the MWP, thus, the MWP was “world-wide.” {Want data? Search on WUWT for “medieval warm period.”}

  49. Dedicated to D. B. Stealey — ALL AMERICAN — thanks for all you do, year in, year out, for truth-in-science!

    You are SO ready to play, a DH (designated hitter), big bat, home-run hittin’, wonder man! Everyone who knows anything about the game (i.e., about genuine science) wants your autograph.

    You too, Jimbo (and Gail — Wonder WOMAN). #(:))

    Way — to — go!

    I love you guys!

    (@ Mr. M-osher: you could be out there hitting home runs, too, if you would just get off the AGW bus…)

  50. The daily sst anomaly is showing a strong warm current developing south of Greenland and running up on the east side of Greenland. This is all bound for the arctic region. Would all of that warmth entering into the Arctic be a part of the driving force that spreads the cold southward, as it vents outward?

    Today,s global temps show a rather cool southern hemisphere. I use this for a quick glance at what the world is showing for temps…http://meteo.france24.com/en/meteo/ville/Paris-CDG/474

    The temps in South Africa and South America are subdued, imo. I was wondering if there might not be an effect like this stemming from the continuing, well above average sea ice. Even the much talked about, by some, Melbourne heat wave has succumbed to a southern cool wave. Isn’t this how it has been in the past?, and isn’t it very likely that we are going to see a repeat of what historical records show? The warmth exiting the Arctic sets the stage for that which comes afterwards.

  51. NevenA says:
    January 28, 2014 at 7:26 am
    —————————————–
    Nice graph. It looks like temps in that region are going to be similar to what was seen in the 30s through the 60s. What a coincidence!

  52. Steve Mosher said; “real bottom line: MWP says nothing about ow much warming we will see.”

    Disagree. Latest climate models back-cast MWP cooler than this study suggests. If today’s arctic temperatures are statistically equivalent (due to said uncertainties), to those of the MWP, when CO2 levels were lower than today, then logically the estimated climate sensitivity to CO2 is currently biased high. Therefore we should see less warming than currently predicted.

  53. Anthony Watts & al:

    Torne- träsk is the long and large lake on the way / (very fameous railway- line) between Kiruna and Narvik. Träsk = equal to “trash” meaning marshland and obviously a bit confused up there in Lappland by those Sæmi and “Finns” up there, who did not understand swedish too well, using the term Tresk rather for a lake.

    It is frozen from December to St.Hans with a lot of very popular ice fishing.

    The landscape is really very beautiful when summer comes at last and after all, and all the flowers but indeed also all the mosquitos suddenly explode in a hurry.

    Can you immagine landscapes quite blue of Geranium sylvana for instance. And jade- green high mountains. And the autumn colours early September.

    That fish of Torne- träsk is very fine smoked, and right outside there in the fjord we have the worlds best codfish. Stoccavisso is when it is hanged and dried and only gets better and better, The same is true also of hanged and dried reindeer. But the wines have to be imported.

    Remember rosso, not bianco, for codfish and for whale- beef. There ain`t no better beef on land.

    The faster and the wilder the cattle, the better the marrow bone soup also.

    Flutemaker- soup is Os femur with Os tibia for instance. The hons of reindeer, although small are quite more pleasant to work with than with ivory. A quite strong and quite smooth and easy to carve- manerial.

    Kiruna keeps a whole mountain and even several mountains of very pure Magnetite Fe3O4, so now they have to moove the very town, after having dug out the very mountain under it.

    Apparently, they have tried to repeat the success of Michael Mann, = the Mann with the scatch you see (and not a hockeystick at all…), who scare up people. But that Mann with the very fameous scatch as I told you, (and not a hockeystick at all..) is only carrying out his duty.

    It is rather easy at Torneträsk because the landscape is steep and cool enough with very old and grey trees everywhere, that hardly rot.

    The worlds oldest known living tree is found a bit further south, in Jämtland a Picea exelsa L prooved to be 7000 years old..!

    Beat that…!

    The reason why those Swedes do not have to fight for theit lives, but rather get their works into Nature, is that they could behave. They must have been relatively sober at work, avoiding fighting peoples hockeysticks, which is quite silly to my opinion. The Sæmi rather make their own ones their own way from local material, I know.

    They simply try and tell the truth and the possible causes and reasons for it, and say that the climate and temperature history at Torne-träsk is obviously “biased” as compared to the rest of the known world. And say that they cannot find why that is so, but so it is.

    LAVDABILIS for that, to the swedes at Torneträsk.

    I have a melody for it, Bruremarsj från Jämtland. But I have to find the right Youtube for you. Or maybe even Bruremarsj fra Lødingen.

    Not all performers and versions are good.

    But, we should also have a proper autentic Joik to it.

  54. Thanks for that lovely post promoting the glories of Scandinavia, Carbo Montanus (at 10:39pm today).

    And, to return your favor, here you go! Skoal!

    “Bruremarsj fra Lødingen

    (I sure hope those words aren’t saying anything disgusting… I have no idea!)

    And, on Side 2, the only Swedish song I know (well, it’s sort of Swedish, lol)
    Hut-Sut Song — Freddy Martin & Orchestra

    #(:))

    Greetings from America (where we have more Swedes than you can say “Ya, shoor, you betcha” to in one lifetime)!

  55. goldminor says: January 28, 2014 at 6:13 pm
    “Even the much talked about, by some, Melbourne heat wave has succumbed to a southern cool wave”

    OK today (Wed) but 42°C yesterday. Heat forecast for the weekend.

  56. Nick Stokes says:
    January 28, 2014 at 11:24 pm
    OK today (Wed) but 42°C yesterday. Heat forecast for the weekend.
    —————————————————————————————-
    I see that. Then it drops back to high 70s on Monday. Enjoy the warmth. Ninety nine F is a nice temp.

  57. goldminor says: January 29, 2014 at 1:45 am
    I don’t think we’re seeing the same forecasts. Here it’s 41°C for Sunday. That’s 106°F. 95&deg’F for Saturday.

  58. I only remind – for those denying the credibility of the data from the Torneträsk, this paper:
    Potential bias in ‘updating’ tree-ring chronologies using regional curve standardisation: Re-processing 1500 years of Torneträsk density and ring-width data, T. M. Melvin, H. Grudd & K. R. Briffa , 2012-13 (http://hol.sagepub.com/content/23/3/364.abstract): “Some previous work found that MXD and TRW chronologies from Torneträsk were inconsistent over the most recent 200 years, even though they both reflect predominantly summer temperature influences on tree growth. We show that this was partly a result of systematic bias in MXD data measurements and partly a result of inhomogeneous sample selection from living trees (modern sample bias). We use refinements of the simple Regional Curve Standardisation (RCS) method of chronology construction to identify and mitigate these biases. The new MXD and TRW chronologies now present a largely consistent picture of long-timescale changes in past summer temperature in this region over their full length, indicating similar levels of summer warmth in the medieval period (MWP, c. ce 900–1100) and the LATTER HALF of the 20th century.

    Also I remind that not only the MWP-MCA had “… similar levels of … … warmth …” as “… the latter half of the 20th century.”
    For example 20 December 2013 was published paper : “External forcing of the early 20th century Arctic warming.”, Suo et al. :
    “The observed Arctic warming during the early 20th century was comparable to present-day warming in terms of magnitude.”
    “… intensified solar radiation and a lull in volcanic activity during the 1920s–1950s can explain much of the early 20th century Arctic warming.”
    “… the local solar irradiation changes play a crucial role in driving the Arctic early 20th century warming.”

    P.S. The conclusions of the work Suo et al. (and another similar papers) very well correspond with the conclusions Semenov and Latif 2012 (http://www.the-cryosphere.net/6/1231/2012/tc-6-1231-2012.pdf): “This suggests that a significant reduction of winter Arctic sea ice extent may have also accompanied the early twentieth century warming …”
    … what “breaks” hockey stick for the arctic ice: arctic ice extent now and in the 20 – 30′s are probably similar (just like its surface).

  59. Should the sub-title not read “New paper finds temperatures were as much as 0.5c warmer in the Arctic during the MWP than the year 2000.”?

    Has anyone any information on arctic temperature anomalies since 2000?

  60. Nick Stokes says:
    January 29, 2014 at 3:22 am
    ————————————–
    I was looking at Meteo/France24 weather site. I see that they have changed their forecast from 99F to 102F for this coming Saturday. They also added an extra 5 degrees to the next two days, Sunday and Monday.

    @ Gail…thanks for the link!

  61. Just to echo TimTheToolMan:

    One theory being put out today is that the temps are really still going up, but it’s hiding in the Arctic where they have a dearth of data. So how do some warmers reconcile calling the MWP a regional warming while calling the exact same warming today global?
    Has anyone published what % of the earth has participated in the fractional degree of warming over the last three decades? For the last thirty years, at least, it appears Antarctica has not. Just how global has the warming been?

  62. I wonder, has anyone bothered to dig through the records of the Hanseatic traders? It might be interesting to see how their records correlate with the tree records. Doing tangentially related research, I did hit a comment in a Norwegian court record stating that the last Hanseatic trade ship visited Greenland in 1386. Now granted, it was buried in a non-indexed court roll written in Old Norse circa 1400…
    There is loads of evidence for how the end of the MWR directly affected politics, economy, social structure. I’ve always thought it might be a valuable lesson from history. But it would mean acknowledging that Climate Change is not the end of the world…

  63. RichieP says:
    “This is not remotely the case.”
    But it is! There is also truth in what you say. I did not say this was their total history but it was, indeed, a part of their early history. The very term “to go Viking” referred to raiding up channels, inlets and bays. It was a part of their history, as with many other peoples who learned to sail the early oceans and rivers and had the military skills to raid along the waterways. No shame in ths since most everywhere people live today was taken by force from one group by another at some point. Trade and warfare commingled during many eras.

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