UPDATE: The Climate Audit server is getting hit with heavy traffic and is slow. If anyone has referenced graphs in blog posts or news articles lease see the mirrored URL list for the graphs at the end of this article and please consider replacement in your posting. I’ve also got a mirrored article of the Climate Audit post from Steve McIntyre. -Anthony
UPDATE2: Related articles
Update: A zoomed look at the broken hockey stick
A look at treemometers and tree ring growth
===
We’ve always suspected that Mann’s tree ring proxies aren’t all they are cracked up to be. The graph below is stunning in it’s message and I’m pleased to present it to WUWT readers. I’m sure the Team is already working up ways to say “it doesn’t matter”.
The QOTW this week centers around this graph:
The quote of the week is:
I hardly know where to begin in terms of commentary on this difference.
– Steve McIntyre, Climate Audit in Yamal: A “Divergence” Problem
The graph above shows what happens to the “Hockey Stick” after additional tree ring data, recently released (after a long and protracted fight over data access) is added to the analysis of Hadley’s archived tree ring data in Yamal, Russia.
All of the sudden, it isn’t the “hottest period in 2000 years” anymore.
Steve writes:
The next graphic compares the RCS chronologies from the two slightly different data sets: red – the RCS chronology calculated from the CRU archive (with the 12 picked cores); black – the RCS chronology calculated using the Schweingruber Yamal sample of living trees instead of the 12 picked trees used in the CRU archive. The difference is breathtaking.
I’ll say. Ding Dong the stick is dead.
This comparison to CRU archive data illustrates the most extreme example of scientific cherry-picking ever seen. As Steve writes in comments at CA:
Also keep in mind the implausibly small size of the current portion of the Yamal archive. It would be one thing if they had only sampled 10 trees and this is what they got. But they selected 10 trees out of a larger population. Because the selection yields such different results from a nearby population sample, there is a compelling prima facie argument that they’ve made biased picks. This is rebuttable. I would welcome hearing the argument on the other side. I’ve notified one dendro of the issue and requested him to assist in the interpretation of the new data (but am not very hopeful that he will speak up.)
See the complete report on this new development in the sordid story of tree ring proxies used for climate interpretation at Climate Audit. And while you are there, please give Steve a hit on the tip jar. With this revelation, he’s earned it.
The next time somebody tells you that tree rings prove we are living in the “hottest period in 2000 years” show them this graph and point them to this Climate Audit article.
Here’s a “cliff’s notes” summary written by Steve’s partner in publication, Ross McKitrick:
Here’s a re-cap of this saga that should make clear the stunning importance of what Steve has found. One point of terminology: a tree ring record from a site is called a chronology, and is made up of tree ring records from individual trees at that site. Multiple tree ring series are combined using standard statistical algorithms that involve detrending and averaging (these methods are not at issue in this thread). A good chronology–good enough for research that is–should have at least 10 trees in it, and typically has much more.
.
1. In a 1995 Nature paper by Briffa, Schweingruber et al., they reported that 1032 was the coldest year of the millennium – right in the middle of the Medieval Warm Period. But the reconstruction depended on 3 short tree ring cores from the Polar Urals whose dating was very problematic. http://www.climateaudit.org/?p=877.
2. In the 1990s, Schweingruber obtained new Polar Urals data with more securely-dated cores for the MWP. Neither Briffa nor Schweingruber published a new Polar Urals chronology using this data. An updated chronology with this data would have yielded a very different picture, namely a warm medieval era and no anomalous 20th century. Rather than using the updated Polar Urals series, Briffa calculated a new chronology from Yamal – one which had an enormous hockey stick shape. After its publication, in virtually every study, Hockey Team members dropped Polar Urals altogether and substituted Briffa’s Yamal series in its place.
http://www.climateaudit.org/?p=528. PS: The exception to this pattern was Esper et al (Science) 2002, which used the combined Polar Urals data. But Esper refused to provide his data. Steve got it in 2006 after extensive quasi-litigation with Science (over 30 email requests and demands).
3. Subsequently, countless studies appeared from the Team that not only used the Yamal data in place of the Polar Urals, but where Yamal had a critical impact on the relative ranking of the 20th century versus the medieval era.
http://www.climateaudit.org/?p=3099
4. Meanwhile Briffa repeatedly refused to release the Yamal measurement data used inhis calculation despite multiple uses of this series at journals that claimed to require data archiving. E.g. http://www.climateaudit.org/?p=542
5. Then one day Briffa et al. published a paper in 2008 using the Yamal series, again without archiving it. However they published in a Phil Tran Royal Soc journal which has strict data sharing rules. Steve got on the case. http://www.climateaudit.org/?p=3266
6. A short time ago, with the help of the journal editors, the data was pried loose and appeared at the CRU web site. http://www.climateaudit.org/?p=7142
7. It turns out that the late 20th century in the Yamal series has only 10 tree ring chronologies after 1990 (5 after 1995), making it too thin a sample to use (according to conventional rules). But the real problem wasn’t that there were only 5-10 late 20th century cores- there must have been a lot more. They were only using a subset of 10 cores as of 1990, but there was no reason to use a small subset. (Had these been randomly selected, this would be a thin sample, but perhaps passable. But it appears that they weren’t randomly selected.)
http://www.climateaudit.org/?p=7142
8. Faced with a sample in the Taymir chronology that likely had 3-4 times as many series as the Yamal chronology, Briffa added in data from other researchers’ samples taken at the Avam site, some 400 km away. He also used data from the Schweingruber sampling program circa 1990, also taken about 400 km from Taymir. Regardless of the merits or otherwise of pooling samples from such disparate locations, this establishes a precedent where Briffa added a Schweingruber site to provide additional samples. This, incidentally, ramped up the hockey-stickness of the (now Avam-) Taymir chronology.
http://www.climateaudit.org/?p=7158
9. Steve thus looked for data from other samples at or near the Yamal site that could have been used to increase the sample size in the Briffa Yamal chronology. He quickly discovered a large set of 34 Schweingruber samples from living trees. Using these instead of the 12 trees in the Briffa (CRU) group that extend to the present yields Figure 2, showing a complete divergence in the 20th century. Thus the Schweingruber data completely contradicts the CRU series. Bear in mind the close collaboration of Schweingruber and Briffa all this time, and their habit of using one another’s data as needed.
10. Combining the CRU and Schweingruber data yields the green line in the 3rd figure above. While it doesn’t go down at the end, neither does it go up, and it yields a medieval era warmer than the present, on the standard interpretation. Thus the key ingredient in a lot of the studies that have been invoked to support the Hockey Stick, namely the Briffa Yamal series (red line above) depends on the influence of a thin subsample of post-1990 chronologies and the exclusion of the (much larger) collection of readily-available Schweingruber data for the same area.
MIRROR URL’s FOR MAIN GRAPHICS IN THE CLIMATE AUDIT POST:
If anyone has referenced the Yamal graphs at CA in blog posts, please use these URL’s so that they get loaded from WordPress high traffic server.
http://wattsupwiththat.files.wordpress.com/2009/09/count_comparison1.gif
http://wattsupwiththat.files.wordpress.com/2009/09/rcs_chronologies_rev2.gif
http://wattsupwiththat.files.wordpress.com/2009/09/rcs_merged_rev2.gif
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But we’ve got to verify it legally, to see
If it is morally, ethic’lly
Spiritually, physically
Positively, absolutely
Undeniably and reliably Dead.
At Climate Audit, Geoff Sherrington says I’d be trying to crack the CRU temperature problem as well as the dendro problem, because in combination they might tell a stronger story than each alone.
With this in mind, I’d like to refer folk here to my second visual piece, this time on the thermometer records circling Yamal that Jeff Id has just published: Delinquent Treering Records To be sure, the records I used are not from CRU but from Daly and GISS – but they are another wedge of good evidence that might help push CRU to release their temperature records that back up the dendro work.
King of Cool (01:00:46) :
Excellent. The Wizard of Oz is one of my favourite movies!
Roger Sowell (21:52:39) :
The analysis was done assuming tree ring chronology is a good proxy for temperature. Even with this assumption, the data don’t support the AGW contention.
Add to all this the simple fact: Trees make terrible thermometers.
“Robert Wood (20:58:35) :
What is the word for “wanker” in climatese?”
[snip]
But it’s still a hockey stick – just the other way up… 🙂
Keith Minto (22:50:23) : refering to ” Roger Sowell (21:52:39)
Wait a minute…weren’t tree ring proxies discredited for purposes of indicating ambient temperature? Weren’t other factors found to be more important in tree-ring growth, such as precipitation? ”
Agreed, isn’t precipitation a major variable that confuses temperature estimation?
######
It all depends on whether you can walk and chew gum at the same time.
Mountain hemlock located along coastal ranges of Alaska and Canada
have tree ring widths that are temperature-sensitive, at least on decadal to centential times scales.
D’Arrigo, R., Villalba, R., and Wiles, G. 2001, Tree-ring estimates of Pacific decadal climate variability, Clim. Dyn., 18, 219−224
This can be comfirmed by comparing the D’Arrigo et al. (2001) tree ring PDO reconstructions with proxy SST reconstructions that have been obtained by Linsley et al. (2000 & 2004) using the Sr/Ca ratios measured in corals at Rarotonga in the South Pacific.
Linsley, B.K., Wellington, G.M., and Schrag, D.P. 2000, Decadal sea surface temperature variability in the subtropical Pacific from 1726 to 1997 A.D., Science, 290, 1145−1148.
Linsley, B.K., Wellington, G.M., Schrag, D.P., Ren, L., Salinger, M.J., and Tudhope, A.W. 2004, Geochemical evidence from corals for changes in the amplitude and spatial pattern of South Pacific interdecadal climate variability over the last 300 years, Climate Dynamics, 22, 1−11.
Other tree ring widths are precipitation sensitive e.g.
The tree ring sites used by MacDonald and Case (2005) were specifically chosen to be at opposite ends of the PDO precipitation dipole that exists between the SW United States and Rocky mountains of western Canada. The tree-ring records used in their study come from James pine (Pinus flexilis), a species that is known to be useful in producing dendroclimatological records of precipitation and stream flow (MacDonald and Case 2005).
MacDonald, G.M., and Case, R.A. 2005, Variations in the Pacific Decadal Oscillation over the past millennium, Geophys. Res. Lett., 32, L08703.
I whole heartily agree that you must be careful in using tree-ring chronologies as temperature proxies temperature but it is just stupidity to claim that all of the temperature data based on tree-ring chronologies are
wrong!
Doug Keenan’s site: http://www.informath.org/ is worth a look. He’s got some peer reviewed papers such as:
“The fraud allegation against some climatic research of Wei-Chyung Wang”, Energy & Environment, 18: 985–995 (2007).
Cognitive Dissonance – here we come!
The most important aspect of this revelation is that the word “uprecedented” can now be deleted from the AGW lexicon.
Future corrected proxy studies alongside projected global cooling now have the potential to completely undermine the standing of AGW advocates. The reputations of people like Hansen, Mann, Schmidt, Romm, Revkin, Stern, Monbiot, et al, now look certain to be trashed. No politician worth their salt will entertain opinion that will lose them votes.
Is it just me? What is the problem with getting this century ring-data? We have several trees in our park that go back some 300 years, and I am sure a core-sample can be extracted from each.
What was so special about the trees that were actually used?
.
Having watched a piece on climate change yesterday, which seemed to involve John Prescott (who, for the uninitiated is a UK labour party, and ex-government oaf, and who now appears to be some sort of “climate spokesperson” for the British government), and the showing of the film “The age of Stupid” (hot on the heels of the Al Gore disaster), I am beginning to wonder if this AGW campaign is unstoppable. What chance have schoolchildren got of forming their own considered opinions when they have this tosh forced down their throats without recourse to the alternative point of view and related science?
>>>No one I know would willingly paint themselves into such a
>>>corner, short of someone taking their children hostage.
You never know… Perhaps the alternative was a walk in the woods with a packet of paracetamol (tylenol) and a pocket-knife. 😉
http://www.dailymail.co.uk/news/article-397256/Why-I-believe-David-Kellys-death-murder-MP.html
.
Is there even one reporter in the ranks here that has the connections and the cojones to place this in the major news outlets?
Mike
Ross McKitrick:
Here’s a re-cap of this saga that should make clear the stunning importance of what Steve has found… the Schweingruber data completely contradicts the CRU series… Combining the CRU and Schweingruber data yields .. a medieval era warmer than the present…
Now let me get this straight.
The IPCC says – “Palaeoclimatic information supports the interpretation that the warmth of the last half century is unusual in at least the previous 1,300 years.”
Hello hello – if the Medieval era was warmer than present then that statement would be incorrect wouldn’t it? Palaeoclimatic information does not, suddenly, support the interpretation that the warmth of the last half century is in any way unusual, even within the previous 1,300 years.
In order to explain this allegedly extraordinary, inexplicable, unusual warmth of the last half century many climate models were used, crunched out by massive computing power. They came to the inescapable conclusion, pronounced by the IPCC that “Most of the observed increase in global average temperatures since the mid-20th century is very likely due to the observed increase in anthropogenic GHG concentrations.”
Why? Because “Observed patterns of warming and their changes [in the last 50 years] are simulated only by models that include anthropogenic forcings.”
But hello hello, this warmth is no longer “unusual”. It has happened before, not so long ago, palaeoclimatically speaking.
And if the models couldn’t simulate the changes of the last 50 years without including “anthropogenic forcings”, which are due to “the observed increase in anthropogenic GHG concentrations”, they could not possibly simulate the warmer medieval era either without these “anthropogenic forcings”.
This is enigmatic. There were no “anthropogenic forcings” in the medieval era.
Could it possibly be there is something commonly wrong in all these climate models?
But then what happens to all those dire warnings based on these models? What happens to cap n trade? carbon tax? CO2 sequestering? closing down our power plants? reducing our carbon footprint? compulsory reduction of our production and wealth in order to “save the world”? All founded on the belief that the warmth of the last 50 years is unusual and alarming.
What happens to Copenhagen? Al Gore? The climate modeling research alarmism industry?
We were fussing over the Emperors coat buttons only to discover he has no clothes.
As explanation to my post above – in the data they only managed to get between 10 – 15 tree samples covering the last few deacdes of tree-ring data.
http://www.climateaudit.org/wp-content/uploads/2009/09/count_comparison1.gif
Again, what is the problem here? Trees covering this era abound the continents by the billion. What was so special about the ones used?
I’m waiting for the facile explanations and spin usually seen from some of the AGW proponents that regularly visit here. Wouldn’t it be nice if one or two of them actually said that this type of “science” should be outed and not tolerated? I can only imagine the words we will soon hear explaining how that this is very minor compared to the gigantic body of ‘evidence’ that has already been presented, how this doesn’t really matter that much, how that since I am not a scientist I cannot possibly understand the beauty and precision involved in manufacturing science sausage…
Mike Bryant
You know what the worse thing about this is?
It’s not that Mann or the IPCC have skewed the data to fit their proposition – that is to be expected of people or groups that use science to push a political agenda.
The worst thing is that the Royal Society – an institution dedicated to impartial science for almost 400 years – has become politicised and corrupted by the current incumbents. That is the most damning indictment of modern society there can be.
I posted a polite, non-controversial item with a link to this site, and the original CA article, on a Guardian CIF discussion today – it was taken down within 45 minutes.
http://www.guardian.co.uk/environment/2009/sep/28/met-office-study-global-warming?commentpage=2&commentposted=1
The re-post has lasted 5 mins so far.
“Facts are sacred” at the Guardian folks.
Ninderthana (02:27:40) :
It all depends on whether you can walk and chew gum at the same time.
Mountain hemlock located along coastal ranges of Alaska and Canada
have tree ring widths that are temperature-sensitive, at least on decadal to centential times scales.
This can be comfirmed by comparing the D’Arrigo et al. (2001) tree ring PDO reconstructions with proxy SST reconstructions that have been obtained by Linsley et al. (2000 & 2004) using the Sr/Ca ratios measured in corals at Rarotonga in the South Pacific.
I whole heartily agree that you must be careful in using tree-ring chronologies as temperature proxies temperature but it is just stupidity to claim that all of the temperature data based on tree-ring chronologies are
wrong!
Given that tree ring temp proxies tend to be offered with resolution far finer than decadal or centenial time scales, that the only confirmation you offer for the single example you quote is another proxy, of perhaps equally, dubious provenance, that there seems to be mounting evidence that the correlations quoted between various proxies for temps is more a product of the statistical manipulations arising from between the ears of the people constructing the proxies than of anything happening in the real world, and that you failed to address the argument I offered that tree foliage maintaining temp ranges narrower than ambient makes it virtually impossible for a tree to create an accurate record of that ambient temp, I’d have to say you fell miserably short of providing proof for your final assertion.
Trees make truly crappy thermometers….
is this m. mann?
Just another fine example of Mann-made Global Warming…
Schweingruber!
Looks like it’s been removed Foxgoose…are we surprised?
to Foxgoose
Your Guardian “Comment is Free” re-comment has already disappeared. Even more bizarre, on the Monbiot thread, IanFremantle posted a simple link to the ClimateAudit story, which was quickly taken down, but not before one IvyMantle had posted a reply along the lines of “what’s all this complex science stuff?’ and quoting three paragraphs of McIntyre verbatim. This wasn’t simply taken down, but disappeared without trace while I was reading it. It’s possible that Guardian lawyers have spotted the fact that any comments on Briffa could, under Britain’s extraordinary laws, be interpreted as libellous.
Reading about Climate Science at the Guardiian is like reading about Berlusconi’s problems in the Italian media. You can see official spokesmen denying things, but no-one knows what it is they’re denying.
REPLY: Keep before and after screen captures of these things, submit them to the newspaper omubudsman if they have one. -a