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
I would like to see a CA post on this.
burn them!!! heretics….burn them all…..oh wait, we can’t burn them, think of the CO2. Can we smother them instead?
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.
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’.
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
It’s still a hockey stick…if you hold it just right….
How I love the MWP! Knowing about it is tremendously liberating.
A link to my cartoon on this topic (I link to this article in the mouseover and the references)
http://itsnotclimatescience.com/0012.2.html
This study I found a while ago is very interesting too:
http://www.spiegel.de/international/zeitgeist/archaeologists-uncover-clues-to-why-vikings-abandoned-greenland-a-876626.html
How is any of this news? Why is it called green land again?
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.
Well they didn’t use a running mean to smooth their data , so they seem to have half an idea what they’re doing at least. Good sign.
The cool period: volcanoes or the sun, or both?
Solar activity should be mentioned as a major factor.
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.
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.
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.
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.
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….
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
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)
Caleb says “The idea that some may have tried to “erase the MWP” may not be something that can be proven by an actual document”
Ahem: http://www.sodahead.com/united-states/9292009-confirmed—global-warming-hockey-stick-is-a-fraud/blog-180309/
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:
http://img16.imagevenue.com/img.php?image=22187_expanded_overview3_122_176lo.jpg
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.
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?
NevenA says:
“Northern Scandinavia gets extrapolated to ‘the Arctic’.”
Nothern Scandinavia is north of the Arctic circle:
http://www.athropolis.com/map2.htm
Ahhhh those were the days.
H.H. Lamb – 1965
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.
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.