First here is Dr. Keith Briffa’s response in entirety direct from his CRU web page:
My attention has been drawn to a comment by Steve McIntyre on the Climate Audit website relating to the pattern of radial tree growth displayed in the ring-width chronology “Yamal” that I first published in Briffa (2000). The substantive implication of McIntyre’s comment (made explicitly in subsequent postings by others) is that the recent data that make up this chronology (i.e. the ring-width measurements from living trees) were purposely selected by me from among a larger available data set, specifically because they exhibited recent growth increases.
This is not the case. 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 applied to the same set of composite sub-fossil and living-tree ring-width measurements provided to me by Rashit Hantemirov and Stepan Shiyatov which forms the basis of a chronology they published (Hantemirov and Shiyatov 2002). In their work they traditionally applied a data processing method (corridor standardisation) that does not preserve evidence of long timescale growth changes. My application of the Regional Curve Standardisation method to these same data was intended to better represent the multi-decadal to centennial growth variations necessary to infer the longer-term variability in average summer temperatures in the Yamal region: to provide a direct comparison with the chronology produced by Hantemirov and Shiyatov.
These authors state that their data (derived mainly from measurements of relic wood dating back over more than 2,000 years) included 17 ring-width series derived from living trees that were between 200-400 years old. These recent data included measurements from at least 3 different locations in the Yamal region. In his piece, McIntyre replaces a number (12) of these original measurement series with more data (34 series) from a single location (not one of the above) within the Yamal region, at which the trees apparently do not show the same overall growth increase registered in our data.
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 but his version of the chronology shows lower relative growth in recent decades than is displayed in my original chronology. 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. I note that McIntyre qualifies the presentation of his version(s) of the chronology by reference to a number of valid points that require further investigation. Subsequent postings appear to pay no heed to these caveats. Whether the McIntyre version is any more robust a representation of regional tree growth in Yamal than my original, remains to be established.
My colleagues and I are working to develop methods that are capable of expressing robust evidence of climate changes using tree-ring data. 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.
We have not yet had a chance to explore the details of McIntyre’s analysis or its implication for temperature reconstruction at Yamal but we have done considerably more analyses exploring chronology production and temperature calibration that have relevance to this issue but they are not yet published. I do not believe that McIntyre’s preliminary post provides sufficient evidence to doubt the reality of unusually high summer temperatures in the last decades of the 20th century.
We will expand on this initial comment on the McIntyre posting when we have had a chance to review the details of his work.
K.R. Briffa
30 Sept 2009
- Briffa, K. R. 2000. Annual climate variability in the Holocene: interpreting the message of ancient trees. Quaternary Science Reviews 19:87-105.
- Briffa, K. R., and T. J. Osborn. 2002. Paleoclimate – Blowing hot and cold. Science 295:2227-2228.
- Briffa, K. R., V. V. Shishov, T. M. Melvin, E. A. Vaganov, H. Grudd, R. M. Hantemirov, M. Eronen, and M. M. Naurzbaev. 2008. Trends in recent temperature and radial tree growth spanning 2000 years across northwest Eurasia. Philosophical Transactions of the Royal Society B-Biological Sciences 363:2271-2284.
- Hantemirov, R. M., and S. G. Shiyatov. 2002. A continuous multimillennial ring-width chronology in Yamal, northwestern Siberia. Holocene 12:717-726.
Now a few points of my own:
1. Plotting the entire Hantemirov and Shiyatov data set, as I’ve done here, shows it to be almost flat not only in the late 20th century, but through much of its period.
How do you explain why your small set of 10 trees shows a late 20th century spike while the majority of Hantemirov and Shiyatov data does not? You write in your rebuttal:
“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.”
Justify your own method of selecting 10 trees out of a much larger data set. You’ve failed to do that. That’s the million dollar question.
Briffa Writes: “My application of the Regional Curve Standardisation method to these same data was intended to better represent the multi-decadal to centennial growth variations necessary to infer the longer-term variability in average summer temperatures in the Yamal region: to provide a direct comparison with the chronology produced by Hantemirov and Shiyatov.”
OK Fair enough, but why not do it for the entire data set, why only a small subset?
2. It appears that your results are heavily influenced by a single tree, as Steve McIntyre has just demonstrated here.
As McIntyre points out: “YAD061 reaches 8 sigma and is the most influential tree in the world.”
Seems like an outlier to me when you have one tree that can skew the entire climate record. Explain yourself on why you failed to catch this.
3. Why the hell did you wait 10 years to release the data? You did yourself no favors by deferring reasonable requests to archive data to enable replication. It was only when you became backed into a corner by The Royal Society that you made the data available. Your delays and roadblocks (such as providing an antique data format of the punched card era), plus refusing to provide metadata says more about your integrity than the data itself. Your actions make it appear that you did not want to release the data at all. Your actions are not consistent with the actions of the vast majority of scientists worldwide when asked for data for replication purposes. Making data available on paper publication for replication is the basis of proper science, which is why The Royal Society called you to task.
Read about it here
Yet while it takes years to produce your data despite repeated requests, you can mount a response to Steve McIntyre’s findings on that data in a couple of days, through illness even.
Do I believe Dr. Keith Briffa? No.
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That’s right, it is not entirely flat. Since many of the cores extend back to the LIA.
Scott A. Mandia (18:12:27),
I honestly wish the alarmist crowd would try and get it right for once. The long accepted hypothesis is natural climate variability. The climate has gone in regular cycles for hundreds of thousands of years. The current climate is benign, and it is well within historical parameters. Nothing unusual is happening. But someone from the alarmist crowd always tries to turn the Scientific Method on its head, and demands that skeptical scientists must falsify whatever odd conjecture comes along:
If I propose a new hypothesis that claims a CO2 breathing dragon lives under my bed, does the mainstream science community have an obligation to falsify my hypothesis? Will the Nobel Prize go to the first person that can show why I am wrong about my pet CO2 dragon? Of course not. Same with AGW.
Skeptical scientists [which is the subset of all good scientists] have no obligation to falsify every hypothesis that comes along. They will, of course, make the attempt — if a hypothesis is testable and falsifiable, and if all raw and adjusted data and their methodologies are made plainly transparent, and available to anyone who asks.
Furthermore, the originator of the new hypothesis must, according to the Scientific Method, do whatever he can to falsify his own hypothesis, and fully cooperate with anyone else trying to falsify it. That’s how science arrives at the truth. But that is not happening with the promoters of the CO2=AGW hypothesis, as the Briffa fiasco makes clear. Those purveying the CO2=AGW hypothesis reject the Scientific Method. They have become politicians, anxious to keep both front feet in the public grant trough.
Climatologist Roy Spencer puts it this way: “No one has falsified the hypothesis that the observed temperature changes are a consequence of natural variability.”
Falsify that hypothesis, and you might get a Nobel. But falsifying the CO2 dragon under my bed, or CO2=AGW? Both have already been falsified; the dragon, by me looking under my bed, and CO2=AGW, by Planet Earth itself, which laughs at the hubris of alarmists by getting chillier as harmless CO2 rises.
I love this. I live in a logging town and county. The lowest guy on the logging crew could give you 10 legit reasons why this stand versus that stand 10 yards away is the same age but bigger.
And did you say punch cards? Can you say “hanging chads”? Mine did that all the fricken time. And often in the same place on the cards. The manufacturing process for those cards resulted in some areas not being readily “punchable”. And if you had a mixed set of cards (different manufacturing dates and sources), you might as well bite the bullet and load up on stiff coffee cuz you will be up all night for several nights in a row pinching off recalcitrant hanging chads.
If this guy’s picture (when he was younger) is any measure, he weren’t drinkin coffee when he prepared his punch cards. Wouldn’t be surprised if the antique cards still have potato chip dust on ’em.
I’ve worked outside since I was a small boy in the 1950’s, and have cut down hundreds of trees. I always check out the rings, for every tree has its own story.
I’ve seen some rather neat tricks pulled off by trees, especially concerning how far they can reach with their roots to find fertilizer or moisture. For example, sugar maple roots will reach, in some cases, well over a hundred feet, and grow a swift net of roots in the peat moss surrounding a lady’s azalea’s root ball, so that the azalea withers, for the maple steals all its water.
I’ve also seen tired old maples perk right up, when a pile of manure is heaped out in a pasture a hundred feet away, and later have seen the tree’s rings, when it was cut down, show its growth surged while that manure was available.
After fifty years you learn a thing or two, even if you don’t take any science classes or major in climatology, and I’ve had a hunch many of the tree-ring theories were bunkum, right from the start.
The bristlecone records seemed a lousy proxy, because at the altitude where they grow it is below freezing nearly every night, and daytime temperatures are only above freezing for something like 10% of the year. They live on the borderline of existence, for trees, because trees go dormant when water freezes. (As soon as it drops below freezing the sap stops dripping into the sugar maple buckets.) Therefore the bristlecone pines were dormant 90% of all days and 99% of all nights, in a sense failing to collect temperature data all that time, yet they were supposedly a very important proxy for the entire planet. To that I just muttered “bunkum.”
But there were other trees in other places. I was skeptical about the data, but until I saw so much was based on a single tree, YAD061, I couldn’t be sure I could just say “bunkum.”
YAD061 looks very much like a tree that grew up in the shade of its elders, and therefore grew slowly, until age or ice-storms or insects removed the elders and the shade. Then, with sunshine and the rotting remains of its elders to feed it, the tree could take off.
I have seen growth patterns much like YAD061 in the rings of many stumps in New Hampshire, and not once have I thought it showed a sign of global warming, or of increased levels of CO2 in the air. Rather the cause is far more simple: A childhood in the under-story, followed by a tree’s “day in the sun.”
Dr. Briffa should spend less time gazing at computer screens, and actually get out and associate with trees more. At the very least, it might be good for his health.
“So is this cherry-picking (according to CA and WUWT) or is this just using the “best data” (Briffa) to get the correct reconstruction?”
OMG.
Let us compare the two methods of selection. The surfacestations method is to survey every site possible, and applying consistent, published, standards which are designed to minimize temperature error. Once this has been done, let the data fall where it will.
Briffa looks for data series which contain hockey sticks using the beard of statistical methods to ‘prove’ that there is a hockey stick in the data. Briffa uses methods that are fine in and of themselves, if one honors the assumptions under which they were developed, which he does not.
How you can say these are the same is totally beyond me. When Craig Loehle did a reconstruction only using data that had been independently proven to be accurate temperature proxies in peer reviewed literature. Guess what? No hockey stick. Briffa is either [snip]. I think he is probably locked into group think.
Liar, liar, pants on fire.
Scott A. Mandia (18:12:27) :
I guess you have a snappy defense of Briffa keeping the data under wraps for 10 years? Let’s hear it.
Are the data for your other hockey sticks out in the open? Are these techniques proven any better than tree rings? I doubt it.
@ur momisugly Scott A. Mandia (18:12:27) :
Group think happens all the time in science. It is known as dogma. It is usually a single scientist who has to fight the battle against dogma, and then the dogma changes.
I can give you many examples of this happening in the past. As a fellow scientist, you should know this is true.
Caleb….you saved the best for last. While all the scientific arguments, discussions and points of view are interesting, there is nothing like a splash of reality on all this to bring in the reality……that maybe it’s an argument about irrelivent data.
For the record, I believe AGW is hokum.
Scott Mandia:
“The reconstructed peak temperatures in the MWP appear comparable to the AD 1961–1990 mean reference level”
If I understand you then your hocky stick is the .5 degree C increase illustrated by GISS from the 1961-1990 mean reference to today. I wonder about the resolution of the reconstruction over the MWP. Graph b in RC’s response appears to show much higher frequency and variation during the MWP. Could not a similar .5 degrees over thirty years have occured and not be easily resolvable?
Leif Svalgaard : “Although YAD061 looks like an outlier, the other trees do show a rise from ~1820 to today [albeit smaller] so the record [based on those threes] does not look entirely flat to me.”
REPLY:[…]There could be hundreds of reasons besides climatic temperature change.
Svalgaard: “So why the fascination with those trees in the first place? If there can be so many reasons besides climate changes, why get all hot under the collar about something that apparently is a poor indicator?”
Response: Because they made claims this was a good indicator.
Svalgaard comes off as an prostrate apologist for poor science.
Caleb (18:59:33) :
Great post, Caleb, this is why I love this site. Insight from people with a lifetime of experience.
Scott A. Mandia (18:12:27)
Thanks for the URL pointers. I am always interested in learning things.
It seems to me that there are a number of related hypotheses:
1. Global temperatures have been rising in parallel with industrial development.
2. The rise in temperatures correlates well with CO2 in the atmosphere.
3. The rising temperatures are controllable by controlling CO2 in the atmosphere.
4. The rise in temperatures can be predicted by the climate models of the IPCC.
5. The rise over the rest of this century will be so large that it is incumbent on society to do whatever it takes to limit production of CO2.
Well, I’m back at #1. That seems to be true. #2 seems to be mostly true. There have been temperature events, though, that appear to be entirely uncorrelated with CO2 concentration. #3 seems to be highly questionable. #4 is just absurd. My response to #5 is “I don’t think so”.
My background is Engineering and Physics. I think we are at the stage of trying to understand the phenomenon. We are a long way from designing a solution. Trying to stampede me by predicting that a crisis is at hand is a waste of time. Trying to overwhelm me with the notion that I should just leave it to the “pro’s” and take their word for it is an insult.
Incidentally, I place a very high premium on being able to predict the outcome of an experiment. I place no value at all on a “consensus” among scientists.
Harold Blue Tooth (18:29:26) :
Ahh, but does it look like a Hockey Stick?
Yep, with a very short handle.
@ur momisugly Leif Svalgaard, Anthony Watts and all my dear colleagues…
Many factors, biological and abiotic, affect the growth of any plant living on this planet. However, a factor exists which is preponderant over the remainder factors like the concentration of CO2, rainfalls, glaciations, etc.; it is the Solar Irradiance. The intensity of the incident light on the Earth’s surface has a proportional effect on photosynthesis, the ultimate cause of plants’ growth. That’s the reason by which the databases from treerings are strongly correlated with the intensity of solar irradiance.
To have a high intensity of incident solar irradiance doesn’t mean a higher temperature because of the physical regulation of the climate by the oceans. There are other factors that modify the plants’ growth, so not always an increase of solar irradiance means an enhanced growth of the plant.
The problem with Mann’s and Briffa’s works is that they show the database from treerings as if they were an accurate mirror of the environmental temperature; this belief is false. Even so, the Media gives more credit to this myth than to the trusty elements taken from careful observations of nature.
The treerings are not a reliable source of information about the environmental paleotemperatures, but for showing that the plant is taking more energy from the incident solar radiation.
There is a very humble tool for measuring the intensity of the light striking on a plant, i.e. the photometer. Ask a biologist if he has detected years with high incidence of light on the surface standing out against years with extremely low incidence of light on the surface. This factor is determinant for the health and robustness of any plant. 🙂
Scott A. Mandia (18:12:27) : “The Nobel Prize goes to the first person that can show why we are all wrong about AGW. That is quite an incentive. Ah, but to have one’s name said along with Galileo, Darwin, and Einstein…..”
Uh huh….but most recently along with Yasser Arafat, the IPPC, and Al Gore….
In today’s politico-scientific climate, most of us will pass or decline on such an award. It would NOT be a compliment.
That is all well and good anyways, Scott, because the BURDEN OF PROOF is on you, not on the Skeptics.
The Skeptics do not have to do anything.
Nothing at all.
There are no real observational reasons to be concerned, outside the normal cycles of the planet, however extreme they might be.
The burden of proof is on your camp.
Produce the evidence. And I don’t mean in the Hollywood world of GCMs either.
Show the actual tropical tropospheric fingerprint.
Show those independent reproductions of hockey sticks and how they were reproduced.
Explain as to why the “group-think” phenomenon [where many individuals are acting as a super-organism] could NOT be in effect in the world-wide scientific community, thanks to the GISS, James Hansen’s control of the data, and the IPCC?
Mass delusions have happened before in human history and they will no doubt repeat themselves.
The REAL problem Scott, is that there are TWO SEPARATE ARGUMENTS here:
Are homo sapiens polluting the Earth, and should they change their ways and invent new technologies? YES
Do the damage that homo sapiens cause really influence mega-cycles that have been around for BILLIONS of years? NO
I’m sorry, but no matter hard our “fire-ant opportunism” may try, we are not going to be able to change the whims of the PDO to any measurable extent.
We can certainly make the Pacific Trash gyre worse though.
[Why isn’t any AGW / IPCC thinktank trying to solve that???]
Pick up your ******* trash people! …Environmental Responsibility 101
I long for the day that Science wrests itself from the political establishment (of either side) and actually solves global problems and makes the Earth better than they found it!
Chris
Norfolk, VA, USA
Patrick Davis (18:45:15) :
For goodness sake have a look at how the CRU is funded. Check how many of the staff are salaried by the UEA. All grants go to pay for researchers and other non salaried staff
Whoever said this isn’t a smoking gun is quite right. The Yamal/Briffa affair isn’t a smoking gun in the sense that it alone kills the AGW scare or it alone shows malfeisance by the Team.
What it does show is that “Trust me, I’m a climate scientist” is no longer valid.
Like Anthony, I do not accept that Keith Briffa is giving full, plain disclosure as to why Yamal should be used as a proxy for anything, why the Polar Urals chronology disappeared after it was updated, nor why Yamal is so artificially sparse in its critical variance.
If Keith Briffa had not replied because of his health problems, I would have understood. But the fact that he could respond so quickly while ill throws a spotlight on his obstructive and uncooperative behaviour over the last ten years while healthy.
Scott A. Mandia (18:12:27) :
Nice bore hole graph. I did notice that the heavy black line seems to be the one that shows the highest increase in temperature or maybe it just hides the other lines. These spaghetti graphs are a good example of “chart junk” they look good but convey little real infromation. A better presentation would be showing each line on a different chart so the reader could see the trend of the line without having to guess what’s behind the darkest one.
I noticed that the paleo reconstructions in the main paper have the modern instrument data spliced onto the paleo data. Comparing apples to oranges comes to mind.
James F. Evans (20:14:26) :
Response: Because they made claims this was a good indicator.
Svalgaard comes off as an prostrate apologist for poor science.
If that is the claim they made, then that is the claim we should address, attack, and beat down if we think otherwise. Not just their various shenanigans. And if it is such a poor indicator, then their poor analysis is moot, because of GIGO.
Are the data for your other hockey sticks out in the open?
the data for the borehole temperature reconstructions certainly are:
http://www.geo.lsa.umich.edu/climate/
Chris V.
Lonnie Thompson?
bugs (18:36:10) : “My colleagues and I are working to develop methods that are capable of expressing robust evidence of climate changes using tree-ring data Mr. [sic] Briffa, I need read no further.
You have now explained yourself, and your goal. That goal has nothing to do with Science, or the discovery of truth, it is only the mundane, self-serving goal of proving your pet theory.
Shame on you, and your colleagues.”
Smoking Gunnimus Maximus.
The BLATANT derailment of the august principles of the Scientific Method in Dr. Briffa’s statement. Thanks for this, Bugs.
To quote Hamlet: “Me thinks he [Briffa] protesteth too much.”
Chris
Norfolk, VA, USA
John A (20:31:07) :
What it does show is that “Trust me, I’m a climate scientist” is no longer valid.
Was it ever?
Here is a far more concise and accurate response to them :
Liar, Liar, Pants on Fire!
“My background is Engineering and Physics. I think we are at the stage of trying to understand the phenomenon. We are a long way from designing a solution. Trying to stampede me by predicting that a crisis is at hand is a waste of time. Trying to overwhelm me with the notion that I should just leave it to the “pro’s” and take their word for it is an insult.
Incidentally, I place a very high premium on being able to predict the outcome of an experiment. I place no value at all on a “consensus” among scientists.”
GRRRR. Spot on. May our species produce more engineers and scientists with this outlook.
May the TRUTH win out. That is what we are after, right?
Chris
Norfolk, VA, USA