From the “we only select wood for hockey stick construction” department.
Steve McIntyre comes back into the fray with a scathing review of just how crappy the tree ring proxies used by Michael Mann were (and still are), and shows without the questionable stripbark portion of the data, why no “hockey stick” appears. But even worse, McIntyre illustrates that Mann, the hockey team, and the paleoclimate community haven’t learned one damn thing with the release of the latest set of tree ring data.
From Climate Audit:
The PAGES (2017) North American network consists entirely of tree rings. Climate Audit readers will recall the unique role of North American stripbark bristlecone chronologies in Mann et al 1998 and Mann et al 2008 (and in the majority of IPCC multiproxy reconstructions). In today’s post, I’ll parse the PAGES2K North American tree ring networks in both PAGES (2013) and PAGES (2017) from two aspects:
- even though PAGES (2013) was held out as the product of superb quality control, more than 80% of the North American tree ring proxies of PAGES (2013) were rejected in 2017, replaced by an almost exactly equal number of tree ring series, the majority of which date back to the early 1990s and which would have been available not just to PAGES (2013), but Mann et al 2008 and even Mann et al 1998;
- the one constant in these large networks are the stripbark bristlecone/foxtail chronologies criticized at Climate Audit since its inception. All 20(!) stripbark chronologies isolated by Mann’s CENSORED directory re-appear not only in Mann et al (2008), but in PAGES (2013). In effect, the paleoclimate community, in apparent solidarity with Mann, ostentatiously flouted the 2006 NAS Panel recommendation to “avoid” stripbark chronologies in temperature reconstructions. In both PAGES (2013) and PAGES (2017), despite ferocious data mining, just as in Mann et al 1998, there is no Hockey Stick shape without the series in Mann’s CENSORED directory.
PAGES2K references: PAGES (2013) 2013 article and PAGES (2017) url; (Supplementary Information).
Background: Stripbark Bristlecones and Mann’s CENSORED Directory
In our 2005 articles, Ross and I pointed out that the Mann’s hockey stick is merely an alter ego for Graybill’s stripbark bristlecone chronologies and that the contribution from all other proxies was nothing more than whitish noise. We noted that Graybill himself had attributed the marked increase in late 19th and 20th century bristlecone growth to CO2 fertilization, not temperature – a theory which was arguably a harbinger of the massive and widespread world greening, especially in dry areas, over the 30 years since Graybill et al (1985).
In a CA blogpost here, I further illustrated the unique contribution of bristlecones by segregating the additive contribution to the MBH98 reconstruction of bristlecones (red) and other proxy classes (e.g. ice cores, non-bristlecone North American tree rings, South American proxies, etc. in blue, green, yellow ). This clearly showed that (1) the distinctive MBH98 Hockey Stick shape arose entirely from bristlecones and that (2) all other proxy classes contributed nothing more than whitish noise – with their combined contribution diminishing in accordance with the Central Limit Theorem of statistics.
Mann had, of course, done a principal components analysis of his North American tree ring network without stripbark bristlecones – an analysis not reported in his articles, but which could be established through reverse engineering of his now notorious CENSORED directory – see CA post here. ) These non-descript PCs further illustrate the non-HSness of the Mann et al 1998 North American tree ring network without strip bark bristlecones.
Figure 2. Plot of five principal components in MBH98 CENSORED directory i.e. without Graybill stripbark chronologies, mainly from bristlecones, but a couple of limber pines.
The 2006 NAS panel stated that stripbark chronologies (i.e. the Graybill bristlecone chronologies) should be “avoided” in temperature reconstructions. Although Mann et al 2008 stated that it was compliant with NAS recommendations, Mann flouted this most essential recommendation by including all 20 stripbark series isolated from the CENSORED analysis.
Because of persistent criticism over the impact of these flawed proxies, Mann et al (2008) made the grandiose assertion that he could get a hockey stick without tree rings (and thus, a fortiori, without stripbark bristlecones) – a claim credulously promoted by Gavin Schmidt at Real Climate. However, it was almost immediately pointed out at Climate Audit (here) that Mann’s non-bristlecone hockey stick critically depended on a Finnish lake sediment “proxy”, the modern portion of which (its blade) had been contaminated by modern agriculture and road construction and which had been used upside-down to its interpretation as a temperature proxy in pre-modern times. Mann was aware of the contamination of lake sediments, but argued that his use of contaminated (and upside down) data was legitimate because he could get a HS without them – in a calculation which used stripbark bristlecones. When challenged to show results without either stripbark bristlecones or upside-down mud, Mann (and Gavin Schmidt) stuck their fingers in their ears, with the larger climate community obtusely refusing to understand a criticism that was obvious to any analyst not subservient to the cause.
In the weeks prior to Climategate, I used increasingly harsher terms for the addiction of the paleoclimate community to the data-snooped stripbark chronologies, describing them as “heroin for paleoclimatologists”, with Briffa’s spurious Yamal chronology as “cocaine” (e.g. herehere), occasioning much pearl-clutching within the hockey stick “community”.
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Conclusions
- ex post screening based on recent proxy trends necessarily biases the resulting data towards a Hockey Stick shape – a criticism made over and over here and at other “ske;ptic” blogs, but not understood by Michael (“I am not a statistician”) Mann and the IPCC paleoclimate “community”;
- the PAGES 2017 North American tree ring network has been severely screened ex post from a much larger candidate population: over the years, approximately 983 different North American tree ring chronologies have been used in MBH98, Mann et al 2008, PAGES 2013 or PAGES 2017. I.e. only ~15% of the underlying population was selected ex post – a procedure which, even with random data, would impart Hockey Stick-ness to any resulting composite
- despite this severe ex post screening (in both PAGES 2013 and PAGES 2017), the composite of all data other than stripbark bristlecones had no noticeable Hockey Stick-ness and does not resemble a temperature proxy.
- PAGES 2013 and PAGES 2017 perpetuate the use of Graybill stripbark chronologies – despite the recommendation of the 2006 NAS Panel that these problematic series be “avoided” in future reconstructions. PAGES 2013 (like Mann et al 2008) used all 20(!) stripbark chronologies, the effect of which had been analysed in Mann’s CENSORED directory. PAGES 2017 continued the use of the most HS stripbark chronologies (Sheep Mt etc) both in the original Graybill version and in a more recent composite (Salzer et al 2014), while adding two stripbark chronologies used in Esper et al 2002 and other IPCC multiproxy studies.
In the past, I charged Mannian paleoclimatologists as being addicted to Graybill stripbark bristlecone chronologies – which I labeled as “heroin for paleoclimatologists” (also describing Briffa’s former Yamal chronology as “cocaine for paleoclimatologists”. Unfortunately, rather than confronting their addiction, Gavin Schmidt and others responded with haughty pearl-clutching indignation, while, behind the scenes, the PAGES consortium doubled down by perpetuating use of these problematic proxies into PAGES 2013 and PAGES 2017.
On this day in 2009, (Oct24) a few weeks before Climategate, I suggested appropriate theme music by Eric Clapton and Velvet Underground. Still apt nine years later.
READ THE ENTIRE ESSAY HERE
In the first comment at Climate Audit, Willis sums up the Mannian mendaciousness very well:
Well, it seems to me that you could have saved yourself lots of work by just reposting your objections to the original Mann HS paper, which are the same objections to every succeeding Mann-alike since then … it’s deja vu all over again.
I gotta say, I am totally gobsmacked. Near as I can tell, they’ve got a perfect record—every error, every wrong process, every data-mining method, every after-the-fact proxy selection, every piece of bad data, every bogus stripbark pine record, they have have all simply been moved from one study, to the next, to the next, without the slightest sign that they have learned from, or even noticed, their egregious errors …
Can’t say enough for your patience in all of this, wading endlessly through the murky waters only to find the same bovine waste material as you found last time.
Gotta say, if I were doing it, I certainly wouldn’t have been as … well … Canadian … in my description of these double-dealing lying malfeasant pseudo-scientists.
Grrrr …
As always, the world owes you immense thanks for your tireless work in revealing this unending deception time after time.
Well done, that man!
w.
Don’t forget, there’s always this book:
Review here, and available on Amazon here.
Just bought a Sherwood hockey stick and the rings are getting smaller . Global cooling is underway . Take it to the bank . The only way to save humanity and polar bears is to burn fossil fuels as rapidly as possible .
Any questions ? Oh yes I own shares in most fossil fuel companies but my interests are purely for saving the planet . Oh yeah and by the way my dog ate my hockey stick so you know… just trust me . I have been studying
Sherwood hockey stick rings for a long time but I sure wish they would bump up the $ subsidies in my pseudoscience industry . I couldn’t make it in real science and university pay sucks without government hand outs . All I need is a pump and dump salesman to sell this crap .
Here’s a question: Has McIntyre or any of his followers ever built a climate reconstruction from scratch? They seem to endlessly pick apart the reconstructions made by others, but I don’t know whether they have actually taken all their good advice and used it to make a reconstruction the “right way.” If Mann is so wrong, why not show him how to do it right?
Their ‘good advice’ is simply that Mann’s approach is neither logically sound, nor impartially implemented. This is hardly a prescription for the development of a “climate model”, although one would hope climate modelers would incorporate such considerations as necessary, but not sufficient, elements of any subsequent effort. It may well be the case that we do not have nearly enough data to discover useful ‘climate models”. Our understanding of climate on a world-wide scale with fairly fine resolution dates back to the development of satellite in the 1960s, and our record of the world from those sources is thus only 50 years in duration, spanning just a handful of solar cycles, and a similar number of large scale eruptions of volcanoes. At the same time, we know that the atmosphere is “chaotic”, in the sense of Lorenz, which means we cannot compute the evolution of atmospheric motions even with the highly detailed information we can derive from satellites. Existing “climate models” are nothing but a shot in the dark, that presume we can ignore what we know about the physics of the atmosphere. It would be nice if they worked, but they don’t. It may be politically inconvenient to recognize this reality, but it is the truth. It would be foolish in the extreme to accept these “models” simply because those who point out the failures of these efforts do not have an alternative. To ignore the critics and embrace these discredited models basically require a religious commitment, which is only too obvious when you examine the supporters of Mann, et al.
Greetings, and hope for a great day for you, Aljo1816:
Posts on this thread are getting thin, so if you are still watching, please allow me to see if I can respectfully comment on your post.
First, as we all know, neither McIntyre nor McKittrick (sp?) are what we would call “scientists” in the same vein that Mann, Schmidt, Tim Ball, David Middleton (frequent contributor here) etc are. Working from obscure memory, one is (I think) and economist, and one is a statistician.
Second, the scientific community, as an aggregate, has deciphered a great deal of information about past climates, on virtually all time scales. We have, for example, established that the later NeoProterozoic (with carbon dioxide concentrations measured in percents [yes, up and down, but percents none the less]) had quite genial climates (e.g., the Ediacaran and Tonian), with times and epochs of extensive glaciation (e.g., Cryogenian). Even with some error bars attached, it is difficult for the current crop of “warmists” (or full-fledged believers in [catastrophic] anthropogenic climate change or [fill-in current meme here]), to account for this discrepancy, since the same factor cannot cause the opposite effect, at different times. That is, if carbon dioxide, in percents of concentrations, was responsible for ‘warm’ episodes, it cannot also be the culprit in causing a glacial pulse of any duration; if it is this “all-powerful” super “greenhouse” gas, there should NOT have been any time that we can discern, for lack of a better term, “cold” or “glacial” conditions.
But it is not in dispute within the geological community that there was a definite, extensive [both temporally and geographically] Late NeoProterozoic glaciation. It is the position of the “skeptic” community, which includes this author, that carbon dioxide is, at best, a very minor player, if it is even a player at all, in the determination of global climate. Numerous other factors are far more powerful, and overwhelm, at all time scales, anything the carbon dioxide might do, or might be capable of doing.
Third, it is axiomatic that as we move forward in time, our resolution of events improves. If we fast-forward from the PreCambrian to the Pleistocene/Holocene transition, we enter into the Holocene Epoch itself. As we approach present-day, there began to exist instrumental temperature records; just a few at first, then more, then more, then … … … until we have satellites (and ground-based and balloon-based records) keeping track of “global” temperature every second of every day, with everyone and his [favorite pet] watching all these data like a hawk.
Between the incipient Holocene, and the beginnings of the rudimentary instrumental temperature records, we have developed methods for estimating past temperatures, including, but not limited to, stalagtites and -mites, written historical records (anecdotes), shore terraces [I grew up around the Lake Bonneville shore terraces, and there’s quite a story to be told from them!), ice cores (Greenland and Antarctica), et cetera … Taking, correlating, cross-checking, quantifying, calibrating, and refining the various methods has produced a reasonable picture of what is likely to have transpired before we had any “hard” data to interpret. There have been, quite literally, thousands of cross-discipline investigators who have pieced all of this together, including those in the sciences themselves, and others who specialize in History, Geography, Agriculture, Linguists, … to name a few.
So here we are: we have what certainly appears to be a decent idea of how “climate” was in the past, before we could directly “measure” it. Insofar as we can tell, things like the Minoan Warm Period, the Roman Warm Period, the Medieval Warm Period, the Little Ice Age, were all real, and were all largely global in scope.
Fourth, M & M could certainly do their own reconstruction; it would be akin to re-inventing the wheel. Somehow, you’re expecting them to come up with something different? or new? or … … … what, exactly?
It is sufficiently-well established that climate has always changed. A changing climate is the norm. There does not exist something that we might call, ‘climate stasis’. It is a myth. Earth climate is a coupled, non-linear, dynamic system, that operates without stationarity*.
And this is where the beef w/ the ‘hokey schtick’ comes in: Mikey and his comrades claimed that they had found that climate changed very little, if at all, for some substantial periods of time (say, nominally, thousands of years) by using these ‘tree-ring’ thermometers. Mikey tried to tell us, who know better, that things like the Minoan and/or Roman and/or Medieval warm periods ( and the consensus view, based on available evidence, is that these time periods were warmer than today) NEVER EVEN HAPPENED! Worse, Mikey, et al, took exceedingly great pains to conceal their “methodology”, the implication being that they KNEW, a priori, that their ‘method(s) was(were) complete garbage. What emerged from the painstaking and roadblocked-at-every-maneuver investigation by M & M were these inconvenient facts: one tree, now known to come from the Yamal pennisula, was given a weighting factor of about 390 times any other “sample”, because it showed exactly what Mikey et al wanted, which is their “signal” of increasing temperatures, co-incident to the Industrial Revolution; the computer algorithm IS a hockey-stick producing program, or in layman terms, it is pre-ordained to show exactly what the programmer wanted. Unless I am mistaken, it would seem to me that most programmers tell their computer to do what they want it to do; somehow I thought that was the aim of “programming”.
As an undergrad, we had lab exercises that involved some basic dendrochonology. We were given unretouched (and live-scale) photographs of some tree rings, and had to deduce a ‘checklist’ of items. We were not told where the trees came from, what time span they represented (other than we had some “old” tree section, a “middle” tree section, and a “young” tree section; one of the goals was to determine from our cross-correlation and analysis, the two extrema and the median section, so there was some absolute overlap in the three time periods represented). It was quite interesting to see periods of abundance, and of stress, and at least one of our “victims” had survived a forest fire. I remember our team struggling to find the overlap; at one point, all those dark/light areas started to blur together, but eventually, we put together a rough chronology from our analysis. We did pass that exercise, by the way.
Fifth, Mikey does not want to know any “proper” way to do a reconstruction. There’s way too much money to be made from shouting “Fire!” in the crowded theatre. Yes, I am accusing Mikey, and just about every other charlatan involved in this whole hoax, of being mercenary. Instead of trying to make a living by doing some genuinely useful research, and solving real problems, the CAGW or CACC alarmists are doing exactly what H. L. Mencken predicted: keeping the populace alarmed with an endless series of hobgoblins, all of the imaginary. They do it solely for profit, and not progress.
So, I hope you enjoyed my dissertation. There is a big problem here on WUWT: if you ask a question, someone just might answer it, so unless you DON’T want an answer, don’t post. I welcome your comments, and will do my best to respond in a timely manner.
My regards to you and yours,
Vlad
*In my undergrad and grad Geophysics classes, we had to use an ad hoc definition, different from the common definition, widely used in the Statistical sciences. This definition formed the basis for the Math employed in the investigation of Earth phenomena. As restrictive as it is, I see a definite application of the same definition to the climate/meteorological sciences. If it is an incorrect application, then I shall consider myself to stand corrected.
Almost,
Look at the graphs above, delete the red bristlecone lines and you have nothing but featureless data on which to try to build a whole new model. Why try?
Steve has answered your question with data, usually a good way to answer
Geoff
That was for Aljo1816.
Geoff
You can always tell a Mann, but you can’t tell him much
You can lead a Mann to real data, but you can’t make him use it properly.
You should see the hockey sticks produced by Professor Lonnie Thompson at Ohio State. H has used Ice core from equatorial glaciers and his are NHL worthy. No Medieval warming and no Little Ice Age, just an alarming hook at the end. He never suspects that firn conditions on a glacier are open and shifting for years, the light oxygen leaving, and calibrating from the current temperature back. It has been published over and over.
“You can lead a Mann to water, but you can’t make him think”.
“the one constant in these large networks are the stripbark bristlecone/foxtail chronologies criticized at Climate Audit since its inception. All 20(!) stripbark chronologies isolated by Mann’s CENSORED directory re-appear not only in Mann et al (2008), but in PAGES (2013). In effect, the paleoclimate community, in apparent solidarity with Mann, ostentatiously flouted the 2006 NAS Panel recommendation to “avoid” stripbark chronologies in temperature reconstructions.”
How was it known that these were strip-bark samples? Were they denoted as such? Strip-bark is a condition of the pines in old age, not a species, and it is these in particular that the NAS panel recommended avoiding.
If McIntyre is going to take the recommendations of the NAS panel as trustworthy, it seems he should also take their conclusions as trustworthy.
“It can be said with a high level of confidence that global mean surface temperature was higher during the last few decades of the 20th century than during any comparable period during the preceding four centuries. This statement is justified by the consistency of the evidence from a wide variety of geographically diverse proxies.
“Less confidence can be placed in large-scale surface temperature reconstructions for the period from A.D. 900 to 1600. Presently available proxy evidence indicates that temperatures at many, but not all, individual locations were higher during the past 25 years than during any period of comparable length since A.D. 900. The uncertainties associated with reconstructing hemispheric mean or global mean temperatures from these data increase substantially backward in time through this period and are not yet fully quantified.
“Very little confidence can be assigned to statements concerning the hemispheric mean or global mean surface temperature prior to about A.D. 900 because of sparse data coverage and because the uncertainties associated with proxy data and the methods used to analyze and combine them are larger than during more recent time periods.Despite these limitations, the committee finds that efforts to reconstruct temperature histories for broad geographic regions using multiproxy methods are an important contribution to climate research and that these large-scale surface temperature reconstructions contain meaningful climatic signals. The individual proxy series used to create these reconstructions generally exhibit strong correlations with local environmental conditions, and in most cases there is a physical, chemical, or physiological reason why the proxy reflects local temperature variations. Our confidence in the results of these reconstructions becomes stronger when multiple independent lines of evidence point to the same general result, as in the case of the Little Ice Age cooling and the 20th century warming.
“The basic conclusion of Mann et al. (1998, 1999) was that the late 20th century warmth in the Northern Hemisphere was unprecedented during at least the last 1,000 years. This conclusion has subsequently been supported by an array of evidence that includes both additional large-scale surface temperature reconstructions and pronounced changes in a variety of local proxy indicators, such as melting on ice caps and the retreat of glaciers around the world, which in many cases appear to be unprecedented during at least the last 2,000 years. Not all individual proxy records indicate that the recent warmth is unprecedented, although a larger fraction of geographically”
…It should be noted that Mann et al. were cognizant of the uncertainty of earlier periods, reflected in the title of their 1999 paper, “Northern Hemisphere temperatures during the past millennium: inferences, uncertainties, and limitations.”
Kristi..
Too bad about this data that proves you wrong:
http://notrickszone.com/2018/03/23/uncertainty-mounts-global-temperature-data-presentation-flat-wrong-new-danish-findings-show/
EdB,
I don’t know why you say it proves me wrong. It’s not my research.
“Prove” is not a scientific term.
I’ve seen that link and abstract already. Hard to evaluate, since the paper is pay-walled. I have reservations about it based on what is available. One paper is not enough to overturn all previous papers until it is adequately assessed. Have you read the whole thing? It seems some are willing to take it as “settling” the issue without the skepticism it warrants.