In a paper published in the Journal of Quaternary Science, Esper et al. (2014) write that tree-ring chronologies of maximum latewood density (MXD) “are most suitable to reconstruct annually resolved summer temperature variations of the late Holocene.” And working with what they call “the world’s two longest MXD-based climate reconstructions” – those of Melvin et al. (2013) and Esper et al. (2012) – they combined portions of each to produce a new-and-improved summer temperature history for northern Europe that stretches all the way “from 17 BC to the present.” And what did they thereby learn?
As the international team of researchers from the Czech Republic, Finland, Germany, Greece, Sweden and Switzerland describes it, this history depicts “a long-term cooling trend of -0.30°C per 1,000 years over the Common Era in northern Europe” (see figure below). Most important of all, however, they note that their temperature reconstruction “has centennial-scale variations superimposed on this trend,” which indicate that “conditions during Medieval and Roman times were probably warmer than in the late 20th century,” when the previously-rising post-Little Ice Age mean global air temperature hit a ceiling of sorts above which it has yet to penetrate.
And so we continue to collect ever more real-world evidence for the fact, that there is nothing unusual, unnatural or unprecedented about the Earth’s current level of warmth.
Paper Reviewed
Esper, J., Duthorn, E., Krusic, P.J., Timonen, M. and Buntgen, U. 2014. Northern European summer temperature variations over the Common Era from integrated tree-ring density records. Journal of Quaternary Science 29: 487-494. http://onlinelibrary.wiley.com/doi/10.1002/jqs.2726/full
Full paper PDF: http://www.blogs.uni-mainz.de/fb09climatology/files/2012/03/Esper_2014_JQS.pdf
References
Esper, J., Frank, D.C., Timonen, M., Zorita, E., Wilson, R.J.S., Luterbacher, J., Holzkamper, S., Fischer, N., Wagner, S., Nievergelt, D., Verstege, A. and Buntgen, U. 2012. Orbital forcing of tree-ring data. Nature Climate Change 2: 862-866.
Melvin, T.M., Grudd, H. and Briffa, K.R. 2013. Potential bias in ‘updating’ tree-ring chronologies using Regional Curve Standardization: reprocessing the Tornetrask maximum-latewood-density data. The Holocene 23: 364-373.
h/t to CO2science.org and D.W. Schnare
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Tree rings are good temperature proxies after all then.
Warmer in Northern Finland and Sweden during MWP. Just like Mann et al found:
http://notrickszone.com/wp-content/uploads/2013/04/Mann-et-al-2009-Journal-of-Science.gif
Yet another validation of Mann’s work.
Here rooter posts an unattributed graphic and claims it validates Mann et all without specifying which. More dubious science brought by a would-be scientist?
Unatttributed. Wellwell. Let’s call it unknown for mpainter.
http://www.sciencemag.org/content/326/5957/1256.short
Rooter, so we are to believe Mann and his cohorts on issues of MWP?
Surely you jest.
mpainter: Mann’s validated by others. Satisfying for you?
Who did the so-called “peer review” of the papers promoted by Mann, and serve as Mann’s propaganda?
Who selected these so-called “peers” for their reviews?
Who selected the people who did the “peer-review” on those papers which supposedly supported Mann’s claims?
Who paid their salaries and their past, present, and future research budgets?
MBH98 has not been validated by anyone else. Hardly satisfying.
Rooter:
You have lots to learn. You need to spend about a month poring over the archives at Climate Audit.
I would suggest Upside-down Tiljander as a good start.
[Snip. Sockpuppetry not allowed. ~mod.]
[Snip. Sockpuppetry not allowed. ~mod.]
Everyone here knows that the silly, popular culture questions and statements about global warming “belief” WITHOUT any reference to a starting date are just that- silly, and sometimes intended to obscure rather than illuminate. Each of us can show agreed upon warming and cooling trends of various lengths by cherry picking our dates. Sure, there are also disagreements about some trends when the instrumentation, proxies, or markers are disputed.
How can we prevent the further dumbing down of science by the journalists, the pundits, and the sometimes ignorant social scientists who talk about belief, but are ignorant of data? It sure appears that many climate scientists and the scientific academies themselves are allowing this to happen for reasons often discussed here. I’m pessimistic and see no hope of turning this ship around soon until the scientific academies take a more principled and scientific approach to the “belief” doctrines that have replaced climate science.
You think the downward temperature trend is from volcanoes, but you’re wrong. It’s from our savior Al Gore and his carbon taxes. Al Gore has saved the world. Actually he has saved the entire universe!!!
Thanks for the link to the full article.
The MWP is chronology interesting, the 8th century was one of the warmest periods, and hard cooling happens in the 12th century, as recorded by Michael the Syrian:
http://rbedrosian.com/Msyr/Morony_2000_Hugoye_Michael.pdf
And by the early 13th century the MWP is over.
And remarkably cold on GISP-2 in the 8th century:
http://climateclash.com/files/2010/12/Aka-5a.jpg
Look at how warm it on top of the Greenland ice sheet today
..
http://hot-topic.co.nz/wp-content/uploads/2011/01/GRIPtempBoxlarge.png
over -27.5 degrees C
Oh, boy, minus 27.5°C . Does that frighten you, sockzratees? How low does it have to go to make you quit wringing your poor hands?
Sure does show that it’s warmer today than during the MWP as per Mr. Ulric Lyons’ graph.
But not warmer than circa 1925-60.
Your poor hands.
Looks like this “hockey stick” is made of ice
http://i61.tinypic.com/2nixu7p.jpg
Reference: http://wattsupwiththat.com/2014/12/18/new-study-two-thousand-years-of-northern-european-summer-temperatures-show-a-downward-trend/#comment-1817064
I think people should quit quoting Skeptical Science’s chart of GRIP temperatures because those are NOT the GRIP site temperatures and Jason Box 2009 did not have the GRIP site in the paper,
It had the GISP2 site or the Summit Camp which has an average annual temperature in Box 2009 of -29.5C and is right now at -30.2C (there is an actual staffed camp there).
http://journals.ametsoc.org/doi/pdf/10.1175/2009JCLI2816.1
Skeptical Science is NOT a reputable site for information about climate.
Do not try to induce questions about the GISP2 temperature record by introducing an obviously FALSE chart from Skeptical Science.
[Snip. Sockpuppetry not allowed. ~mod.]
David Socrates
December 19, 2014 at 4:01 pm
“Sure does show that it’s warmer today than during the MWP as per Mr. Ulric Lyons’ graph.”
Which would only imply that is now colder on the mid latitudes than during the MWP.
In Dansgaard’s book about the Greenland ice core efforts, he reports the average annual temperature at the GRIP site as -32.0C.
Skeptical Science and/or Jason Box are, therefore, not telling the truth.
http://www.iceandclimate.nbi.ku.dk/publications/FrozenAnnals.pdf/
Yes Bill, there is a large disparity between the two series. Personally I think that 1250-1850 on the long GISP series looks rather fishy, the range is very small, and I would expect warm spikes in the coldest parts of the solar minima. As here with the 1690’s and 1807-1817, and also the very cold 1836-1845:
http://iceagenow.info/wp-content/uploads/2011/05/Easterbrook-GISP2-Greenland-ice-core.jpg
[Snip. Sockpuppetry not allowed. ~mod.]
My reply referred to the chart supplied by D. Socrates. Your incoherent squabble is with him.
You should be aware, rooter, that cooked data does not sell at this blog.
Take it to SKS or hotwhopper, where they love Upside down Tiljander, hockey sticks, and all of that garbage.
Incoherence will not win the day for you, rooter. You must squabble with sock rates over the difference in the two plots.
You should be aware that most people do not wet their britches when it is minus 27°C. It only makes them colder.
Here some real data:
http://www.dmi.dk/klima/klimaet-frem-til-i-dag/groenland/
http://www.dmi.dk/nyheder/arkiv/nyheder-2014/05/ny-rapport-sydvestgroenlands-temperatur-siden-1784/
Looks like a cut off hockey stick. The data must be wrong somehow.
Socrates / Janne ; Wouldn’t it make more sense to align the two series to the common time period that Janne marked on the weather station chart???
For a look at (and an excellent visual demonstration of) how cycles of different lengths can oppose or combine to cancel or enhance each other, see the ‘Newton’s Pendulum”
It is interesting to see this and think about the temperature swings from various natural and cyclical forcings.
You wrote quite correctly: “when the previously-rising post-Little Ice Age mean global air temperature hit a ceiling of sorts above which it has yet to penetrate.”
However, according to the plot of the 934-year and superimposed 60-year cycles in the scalar sum of the angular momentum of the Sun and all the planets (which correlates with Earth’s climate cycles as seen here) we have not yet reached the maximum in that 934-year cycle. That maximum will be reached after the next 30 years of warming from 2028 to 2058. Because that maximum will probably be about 0.3 to 0.5 degrees above the 1998 maximum, that could level out the long-term cooling trend discussed in the article. I suggest it is only being seen as such because it is not based on the predicted maximum in the current 934-year cycle.
And this comment was posted on most of the listed climate blogs recently.
Basically, then, this trendline matches Mann’s trendline – except for the ending 20 decades. But because he homogenized the data so much, he washed out the MWP and the LIA.
When he did that, and I saw it, it was too much for me. He simply erased two periods – one up and one down – that DID exist, so there had to be either something in his methods or he had to do some serious explaining. “Extraordinary claims require extraordinary proof.” The climate community and pols let him get away with his extraordinary claim – and then they made THAT into the main stream thinking.
Don’t blame Mann as much as blame the people who didn’t do THEIR due diligence in asking how he came up with such an outlandish claim. But he told them what they wanted to see (catastrophe on the horizon!), so they accepted it.
*** Note that Esper was one of The Mann-Jones Team, or at least on the close periphery. That this comes from Esper sounds like the man got some principles along the way.
I find it very interesting that, there is so much in dispute about present day Global Climate. We know a great deal about what’s going on, with all the advantages of modern technologies etc. Yet there is still a great deal to learn. How can we have any certainty about the past? We have good broad outlines, but not to the extent of what we know what’s going on today. For me, what is even more amazing, is the confidence expressed by some, that they are so certain what will happen in the future.
Eamon.
I’d have thought sunlight would be more important than a few degrees temperature to improve plant growth. Perhaps it is warm but cloudy or cool but sunny.
Zemlik –
Sunlight? Added to site slope, available site nutrients, competition from nearby trees, etc., of COURSE it is a factor. Which (or which combination) actually tracks with growth of tree rings? They claim to know, don’t they?
On that line of thought, milep over at ClimateAudit.com just a short time ago posted this link:
http://timharford.com/2014/11/finance-and-the-jelly-bean-problem/
I posted a comment about rainfall and temps myself that ties in with this, too. Several growth factors, and the dendroclimatologists assume ALL of those other than temperature are constant. It is an analog to global warmist scientists, who think that CO2 and only CO2 is underlying late-20th-century warming – the warmists MUST and DO assume all natural forcings are constant. Without such an assumption, they’ve got nothin’. WITH such an assumption, have they been digging themselves into a hole?
I track down such thinking to the astronomers who about 100 years ago began assuming that all stars of a certain type had the same intrinsic brightness (which I thought was a terrible assumption when I first heard it and still do). Thus was born the beginnings of all the distance determinations which led to the Doppler redshift and then to the Big Bang. (Are they right? Perhaps, but such an assumption is so wrought with blind-alley-thinking possibilities that I simply cringe whenever I see it again, in any discipline. If they have gone down a blind alley, it will take a VERY long time for them to admit it and at the risk of many decades of lost progress.)
Well there is the expression ” blind you with science”.
I agree I also have always had questions about what is being measured.
having tried to imagine the construction of the Universe I can report that it is really difficult for a mind to grasp the reality of it.
I suppose a lot of people have noticed that too.
I really had to think about water being densest at 4 degrees C and that if it did not have this property life would most likely not have evolved because it would be pushed up to flap about and die on the surface of ice. And this seems to suggested that to find warming you need to measure the bottom of the oceans rather than the top.