Today while looking for something else I came across an interesting web page on the National Climatic Data Center Server that showed a study from 2002
A continuous multimillennial ring-width chronology in Yamal, northwestern Siberia (PDF) by Rashit M. Hantemirov and Stepan G. Shiyatov
That study was tremendously well done, with over 2000 cores, seemed pretty germane to the issues of paleodendroclimatology we’ve been discussing as of late. Jeff Id touched on it breifly at the Air Vent in Circling Yamal – delinquent treering records?
A WUWT readers know, the Briffa tree ring data that purports to show a “hockey stick” of warming in the late 20th century has now become highly suspect, and appears to have been the result of hand selected trees as opposed to using the larger data set available for the region.
OK, first the obligatory Briffa (Hadley Climate Research Unit) tree ring data versus Steve McIntyre’s plot of the recently available Schweingruber data from the same region.
The Hantemirov- Shiyatov (HS) tree ring data that I downloaded from the NCDC is available from their FTP server here. I simply downloaded it and plotted it from the present back to the year 0AD (even though it extends much further back to the year 2067 BC) so that it would have a similar x scale to the Briffa data plot above for easy comparison. I also plotted a polynomial curve fit to the data to illustrate trend slope, plus a 30 year running average since 30 years is our currently accepted period for climate analysis.
Compare it to the Briffa (CRU) data above.
When I first saw this plot, I thought I had done something wrong. It was, well, just too flat. But I double checked my data import, the plot, the tools used to plot, and the output by running it 2 more times from scratch. Then I had Jeff Id over at the air vent take a look at it. He concurs that I’ve plotted the data correctly.
The trend is flat as road kill for the past 2000 years, though it does show an ever so slight cooling.
So the next task was to look at more recent times. Here’s the last 200 years of the data:
Still flat as road kill.
Finally, since Tom P made a big deal out of the late 20th century with his analysis where he made the mistake of combining two data sets that had different end points, I thought I’d show the late 20th century also:
Still flat.
Note that in the graph done by Steve McIntyre showing both Briffa and Schweingruber data, both of those data sets are also quite flat until we get into the late 20th century. So out of the 3 data sets we’ve looked at, the Briffa data, the data kept hidden for almost 10 years, is the only one that shows any propensity for sudden 20th century warming.
But don’t take my word for it that this record is so flat. Look at the authors results. Their results seem identical to what I’ve plotted. Here is the last 2000 years of data charted taken from their paper:
Figure 8 Reconstructed southern Yamal mean June–July temperature anomalies relative to mean of the full reconstructed series.
But for those that want more close up views, I’ve done some additional graphs. Since the authors used a 50 year window in one of their graphs I did the same. I also changed the Y scale to show a zoomed in +/- 0.3°C as the range rather than the +/- 4.0°C the authors used in the plot above. Some details begin to emerge, but once again the trend is essentially flat, and slightly negative.
And here are the last 200 years zoomed
The period around 1800 was warmer than the late 20th century according to the data viewed this way, but we can see that slight rise in temperature for the 20th century. However compared to the rest of the Yamal HS data record it appears insignificant.
The authors insist that this wood contains a valid climatological record.
Holocene deposits in the southern Yamal Peninsula contain a large amount of subfossil tree remains: tree trunks, roots and branches. This is the result of intensive accumulation and the good preservation of buried wood in the permafrost. The occurrence of this material in the present-day tundra zone of the Yamal Peninsula was described for the first time by Zhitkov (1913). Later, Tikhomirov (1941) showed that, on the evidence of remains of trees preserved in peat, during the warmest period of the Holocene, the northern tree-line reached the central region of the Yamal Peninsula (up to 70°N), whereas today the polar timberline passes through the southernmost part of the peninsula at a latitude of 67°309 N.
By 1964, attention had been drawn to the potential significance of Yamal subfossil wood for reconstructing climatic and other natural processes over many thousand years, as a result of fieldwork carried out within the valley of the Khadytayakha River in the southern part of the Yamal Peninsula (Shiyatov and Surkov, 1990).
I was impressed with the amount of field work that went into this paper. The authors write:
We travelled by helicopter to the upper reaches of the river to be sampled. Small boats were then used for locating and collecting cross-sections from wood exposed along the riverbanks. It was also possible, when going with the stream, to explore the nearest lakes.
The best-preserved material from an individual tree is usually found at the base of the trunk, near to the roots. However, many of these remains are radially cracked and it is necessary to tie cross-sections, cut from these trunks or roots, using aluminum wire before sawing. This wire is left in place afterwards as the sections are air-dried.
Here’s how they got many of the tree samples using a rubber boat:
And here is how they sum up the last 2000 years from a tree line analysis they did:
From the beginning of the first century bc to about the start of the sixth century ad, generally warm conditions prevailed. Then began a quasi 400-year oscillation of temperature, cooling occurring in about 550–700, 950–1100, 1350–1500 and 1700–1900. Warming occurred in the intermediate periods and during the twentieth century. The more northerly tree-line suggests that the most favourable conditions during the last two millennia apparently occurred at around ad 500 and during the period 1200–1300. It is interesting to note that the current position of the tree-line in Yamal is south of the position it has attained during most of the last three and a half millennia, and it may well be that it has not yet shifted fully in response to the warming of the last century.
Interestingly while the authors note some warming in the last century, they don’t draw a lot of attention to it, or refer to it as being “unprecedented” in any way. There’s no graphs of nor mention of “hockey stocks” either.
Here’s the link to the source data:
ftp://ftp.ncdc.noaa.gov/pub/data/paleo/treering/reconstructions/asia/russia/yamal_2002.txt
Feel free to make some plots of your own.
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UPDATE: While I had originally surmised this data supported Steve McIntyre’s recent findings with respect to Briffa, Steve notes in comments that the methodology is different between the two data sets:
Steve McIntyre: I’ve made MANY references to Hantemirov and Shiyatov 2002 in my posts on Yamal. In my first post on Yamal after getting access to the data, I discussed the Hantemirov and Shiyatov 2002 reconstruction as archived at NCDC see http://www.climateaudit.org/?p=7142
In that post, I observed that the standardization method used in H and S 2002 was different than Briffa 2000, that the H and S method would be unable to recover centennial scale variability and that it was not relevant to the issues at hand.
The H and S reconstruction does not “support” my point in respect to Yamal. It’s irrelevant to it.
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Here is one of Keith Briffa’s explicit statements: “My colleagues and I are working to develop methods that are capable of expressing robust evidence of climate changes using tree-ring data.” If that is not an implicit admission that present methods are not robust, then I don’t know what it is.
====================================
Well, RC has has found its voice:
http://www.realclimate.org/index.php/archives/2009/09/hey-ya-mal/#more-1184
In his explanation, DR Briffa maintains he is working on developing methods to give robust evidence of climate data using tree rings.
That sounds very tentative. At best the climate reconstruction would express drought, humidity, c02 levels and other climatic factors. Certainly not a temperature reconstruction
Re: Robert E. Phelan (07:44:41) :
Well, RC has has found its voice:
“http://www.realclimate.org/index.php/archives/2009/09/hey-ya-mal/#more-1184”
—
With a lot of real argumentation, very refreshing. I’d guess the Yamal wind is over.
Message to readers
September 30, 2009 · 56 Comments
Thanks to all for continuing to visit in spite of the absence of posts. My injury was more severe than I thought at first. However, my wife is willing to help with typing so I hope to post something before too long … I can’t yet say exactly when, but possibly soon.
As for Steve McIntyre’s latest: I’m really not that interested. He just doesn’t have the credibility to merit attention. I have way better things to do.
The above from tamino
http://tamino.wordpress.com/2009/09/30/message-to-readers/
! Steve is claimed to be irrelevant
2 Playing the injured victum card.
I enjoy this discussion board, It is fresh and fair.
“More seriously, many of you will have noticed yet more blogarrhea about tree rings this week…” -RealClimate
LOL! Ouch, someone’s feelings have been hurt! 😀
I guess tree rings are okay if they back up AGW, but are just “blogarrhea” if they don’t.
And Keith Briffa is ill.
Due to illness, Keith is currently away. He will not be able to respond to emails for some time. He is not currently accepting invitations to review papers or proposals.
Congratulations for helping to reveal the [snip] selection of data used to create the now-infamous hockey-stick temperature rise prediction. But apparently it hasn’t bothered the UK’s purveyors of climate hysteria at Oxford University’s climate “science” conference. On Monday, 28 September, according to a report in the Guardian, Richard Betts, head of climate hysterics “…at the Met Office Hadley Centre, presented a study demonstrating that the world could see a 4C rise as soon as 2060-2070…”
Anthony, I wonder — did Betts present a new “hockey stick” study, or just a regurgitation of the same old junk science? What kind of “climate science conference” would ignore the mammoth science scandal that is developing over the [snip] of the original “hockey stick?
Oooookey Dokey!
Environmental Wackos and zany know it alls like Algore MUST now know that their lie has been exposed.
No warming only cooked climate books. This is now part of the historical record.
Anyone or any institution that claims the planet is dangerously warming has lost the right to say so without being called out for what they are: despicable liars.
We are now entering our second decade of cooling. Over 95% of all increases in CO2 in the atmosphere is completely natural.
TEAM AGW has no warming, their models are failures, their data is cooked, and the theory of CO2 being able to warm the planet has been debunked over and over again.
Anybody dissagree that these are the facts as we now know them to be?
Americans need to scream at their congressmen to call an end to the con game. We are needlessly stepping on the neck of our energy supply so that a few ponzi schemers like Algore can become “carbon billionaires.”
If a foreign nation tried to cut our energy supplies with this hoax we would declare war on them. I think that lying environuts have been at war with us for years. Now we have the proof.
Briffa has made an initial response to McIntyre:
http://www.cru.uea.ac.uk/cru/people/briffa/yamal2000/
h/t Jennifer Marohasy
tonyb,
This study and others by McDonald may offer some insight into how responsive treelines are to temperature. You have to dig in a bit however. Note how gentle they are when it comes to inconsistency with the temperature record.
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2606780/
My read is that they’re pretty sensitive, which anyone who’s ever mowed a field at the margins can probably already tell you.
Mark
These trees are just not teleconnected and nobody told them….
Re: TomLama (08:07:30) :
“Over 95% of all increases in CO2 in the atmosphere is completely natural. ”
—
It’s just a bit strange that the C-isotope distribution in the atmosphere has changed exactly as if all the extra CO2 would have come from fossil carbon. Eh, but isotopes? That is esoteric stuff, not at all visible to the naked laymen’s eyes, so the myth of isotopes can easily be explained away. Using nukes if need be.
One does rarely encounter mention of hockey stocks. There are some pretty certificates available from Florida Panthers Holdings, Inc.
I do have some problems with tree lines too. They may also respond to CO2 levels, if CO2 levels are the limiting factor at those latitudes/altitudes. Do you know about any paper that proves CO2 levels are not a limiting factor? (I am not supporting anything, I am just curious) it seems difficult to prove.
There are some peer reviewed papers proving that plants that grow in atmospheres with 750 ppm of CO2 are more resistant to low humidity levels. (you can look at http://www.co2science.com if you are interested) Maybe augmented CO2 levels allow trees growing at higher altitudes.
“The Yamal tree-ring chronology (see also Briffa and Osborn 2002, Briffa et al. 2008) was based on the application of a tree-ring processing method …” A method? What method?
“The basis for McIntyre’s selection of which of our (i.e. Hantemirov and Shiyatov’s) data to exclude and which to use in replacement is not clear …” He tried to explain it, and undoubtedly can provide more detail. Where did you explain yours?
Mark Young (08:21:31) : I don’t know if this is relevant but my garden slightly expanded in 2006 here in London, although in 2008 showed greater vegetation than 2006. That is: greater yield for the same area than 2006, yet 2006 was considerably hotter during the summer, whilst 2008 was considerably cooler and wetter
OT: You know, universities and colleges seem to spend a lot of effort to impress upon students the seriousness of plagiarism and academic ethics then we elect plagiarists to high office and let researchers use selection to fabricate data sets and watch as science journals ignore their own publication criteria and universities conceal what is happening. Why don’t we just tell kids the truth: do whatever you want and if you get caught, make sure you have friends to help you deny, spin and rationalize.
How are physicists supposed to go up against flat-earth proponents when all that is said about the power of the peer review publication system and evidence-based application of the scientific method is being made into a complete farce? Does the science community have to decay to the point that journalism has reached before a problem is acknowledged?
I am not able to ask skeptical questions on Realclimate.org, they delete all my messages.
North Korea like, one way communications over there.
http://www.realclimate.org/index.php/archives/2009/09/hey-ya-mal/
I think Steve’s just this minute got server problems again
Looking at Gavins graph b of the non tree ring temperature reconstruction (blue curve) of the Northern Hemisphere (land and water) we see the HADCRU temperature splice (red) for the last 130 years of approximately 1 degree C. However looking at spikes from the MWP to the LIA the graph reveal as much as a 1.2 degree C range. I do not see a hockey stick in this reconstruction and certainly does not look like the media or IPCC Hockey stick.
It’s been my experience from looking at a lot of tree stumps, that a tree ring for any year can vary in width as you go around its circumference. That means that cores taken from the same tree but from different azimuths can yield very different patterns. I wonder if multiple cores are taken from each tree to compensate for this fact?
Correlation coefficients with temperature were calculated, but were they adjusted for any correlation with rainfall?
btw’s –
They’re thinking of deleting Anthony’s bio on Wikipedia :
“This article may not meet the notability guideline for biographies. Please help to establish notability by adding reliable, secondary sources about the topic. If notability cannot be established, the article is likely to be merged or deleted. (September 2009)”
Get well card to K. Briffa.
Kaboom.
I’ll second your proposal that Steve McIntyre deserves a Nobel Prize for this effort.
Now…if we can only get those Muppets at the BBC to see the jig is up for AGW…that’s something I have been working on for the last 3 years.
Nil desperandum…I will get there eventually because I have no intention of giving up. Director General Mark Thompson must know by now that I am an itch he cannot scratch!
I referenced John who said
Briffa has commented –
http://go2.wordpress.com/?id=725X1342&site=wattsupwiththat.wordpress.com&url=http%3A%2F%2Fwww.cru.uea.ac.uk%2Fcru%2Fpeople%2Fbriffa%2Fyamal2000%2F
“”Chronologies are constructed independently and are subsequently compared with climate data to measure the association and quantify the reliability of using the tree-ring data as a proxy for temperature variations. ”
I then asked;
“What climate data is it compared with? Is the material used a proxy for a proxy, or a proxy for a thermometer? Anyone throw any light on it?”
David over at CA said in reply to someone else;
“Since noone else has reacted to your seemingly sensible suggestion, I will.
The problem is that the local temperatures have not risen in any significant way. Real temperatures for the area do not match the cherry picked treemometers meteoric rise, and are more or less flat, with maybe a slight rise. Certainly not enough to have a significant noticable effect on the permafrost (never mind being miraculously localised for the particular patch of ground under this amazing tree).
At this point, anybody schooled in science asks themselves “what ? you mean the trees are not correlated to local temperatures prior to being used as proxies ??”
The amazing answer is yes. These climate scientists do NOT correlate their proxies with local temperatures, but with the whole Northern Hemisphere temperature AVERAGE.
The climate scientists have a term for this. They call it “teleconnection”, and do not seek to actually demonstrate that it is a fact, but take it instead on faith that if the proxy has risen in line with the Northern Hemisphere temperature average, then there IS a connection.
Yes, it’s scary that so much fear mongering goes on regarding unprecedented temperature changes when the connections are so weak, but welcome to climate science.”
Anyone care to elaborate on my original comment and the proxy reply by David?
tonyb
Okay, Briffa has denied picking out individual trees. That is to be expected. But his selection process is still not described. He says that Hantemirov and Shiyatov had 17 series from living trees. That seems like a very small sample if they took 2000 cores as Anthony tells us. In any case, how were the 12 selected from the 17.
I think that Briffa gives us a hint about how his cherry picking actually works.
“We do not select tree-core samples based on comparison with climate data. Chronologies are constructed independently and are subsequently compared with climate data to measure the association and quantify the reliability of using the tree-ring data as a proxy for temperature variations. ”
So, basically, they generate the chronologies. After they are created they are checked against surface temp data to “quantify the reliability”. Of course this implies that if a chronology does not match the surface temp data, it will be thrown out. It’s a fine distinction, but it’s still cherry picking. The fact that the picking process occures after the chronology has been created seems to be unimportant. This excuse is, of course, the one that was presented by Tom P. I’m still trying to figure out if Tom P. was Briffa.
Briffa objects to the way that McIntyre uses his data when he says.
“He offers no justification for excluding the original data; and in one version of the chronology where he retains them, he appears to give them inappropriate low weights.”
Of course Briffa gives no justification for excluding data either. Actually, McIntyre’s justification is that the data might have been cherry picked. But after admitting that McIntyre does produce a chart with the combined data in the next breath, he claims that he gave them “inappropriate low weights”. I can’t speak to the weighing issue. I hope that Steve will do that. But some of his complaints also remind me of Tom P’s complaints.
REPLY: I agree, the density of these people is astounding. See main page for an update. – Anthony