20 Years Later, The ‘Hockey Stick’ Graph Behind Waves Of Climate Alarmism Is Still In Dispute

It was 20 years ago, climate scientist Michael Mann published his famous “hockey stick” graph that he says “galvanized climate action” by showing unprecedented global warming.

Original “hockey stick” temperature graph in Nature, 1998. The Y axis shows the Northern hemisphere mean temperature, in degrees Celsius; the zero line corresponds to the 1902 – 1980 mean. Credit: “Global-scale Temperature Patterns and Climate Forcing over the Past Six Centuries,” by Michael E. Mann et al. in Nature, Vol. 392, April 23, 1998

Mann used the 20-year anniversary of the graph to opine on the “industry-funded” attacks “to discredit the iconic symbol of the human impact on our climate,” which Mann claimed had withstood criticism.

“Yet, in the 20 years since the original hockey stick publication, independent studies, again and again, have overwhelmingly reaffirmed our findings, including the key conclusion: recent warming is unprecedented over at least the past millennium,” Mann wrote in Scientific American on April 20.

However, the two Canadian researchers who found serious flaws in the “hockey stick” study’s data and methodology disputed Mann’s characterization of the graph’s legacy.

“For everyone else, the debate was about data and statistical methods,” Ross McKitrick, an economics professor at the University of Guelph in Canada.

“For Mann, judging by his rant, it was all a giant political conspiracy against him and his heroic crusade to save the planet. He still won’t acknowledge the errors in his work,” said McKitrick who co-authored a 2003 study with mining executive Steven McIntyre that challenged Mann’s work.

Mann’s “hockey stick” graph, first published in 1998, was featured prominently in the U.N. 2001 climate report. The graph showed a spike in global average temperature in the 20th century after about 500 years of stability.

The “hockey stick” went viral and become a rallying cry for environmentalists and politicians who opposed fossil fuels and wanted climate policies. Former Vice President Al Gore even featured the “hockey stick” graph in his 2006 film “An Inconvenient Truth.” The graph also came under intense criticism, even sparking an investigation by GOP lawmakers.

Global warming skeptics were heavily critical of the “hockey stick” graph, especially in the wake of McKitrick’s and McIntyre’s 2003 study. Their study found serious flaws in the proxy data Mann relied upon to estimate temperatures going back hundreds of years.

The Canadians’ 2003 study showed the “hockey stick” curve “is primarily an artifact of poor data handling, obsolete data and incorrect calculation of principal components.” When the data was corrected it showed a warm period in the 15th century that exceeds the warmth of the 20th century.

McIntyre and McKitrick also published a study on Mann’s “hockey stick” graph in 2005.

However, Mann wrote that “dozens of groups of scientists” had validated his 1998 study. Mann specifically pointed to a 2006 U.S. National Academy of Sciences (NAS) report that “affirmed our findings in an exhaustive independent review published in June 2006.”

Even McIntyre said subsequent studies have “produced somewhat hockey-stick-ish temperature reconstructions,” but added, “none (NONE) of our specific criticisms of Mann’s methods, proxies, and false claims has been rebutted.”

“The NAS report did not vindicate him, it said his methods were biased, and his results depended on faulty bristlecone pine records that shouldn’t be used by researchers,” McKitrick told The Daily Caller News Foundation by email.

“The NAS panel also cautioned against conclusions about warming more than 600 years back and said uncertainties were being underestimated,” McKitrick said. “That criticism applies to many subsequent studies as well.”

Indeed, the 2006 NAS reviewers agreed with the “substance” of Mann’s study but noted “claims for the earlier period covered by the study, from AD 900 to 1600, are less certain,” Nature.com reported at the time.

The NAS noted the uncertainties were “not communicated as clearly as they could have been” and “confirmed some problems with the statistics,” but those problems only had a minor impact on the overall finding, Nature.com reported.

However, NAS reviewers were extremely critical of the U.N. Intergovernmental Panel on Climate Change featuring the report so prominently in its 2001 assessment.

“The IPCC used it as a visual prominently in the report,” Kurt Cuffey, a NAS reviewer told Nature.com. “I think that sent a very misleading message about how resolved this part of the scientific research was.”

At the time, Mann said he was “very happy” with the NAS’s results and in the years since used his experience in defending the “hockey stick” to effectively label himself as a martyr for fighting global warming. Mann said attacks against him continued despite other researchers validating his results.

“There is no legitimate scientific debate on those points, despite the ongoing effort by some people and groups to convince the public otherwise,” Mann wrote in April as part of a screed against his critics.

Mann asks

‘What more noble cause is there than to fight to preserve our planet.’

How about the noble cause of not misleading readers with biased methods and bad data?” McKitrick said.

Read more at Daily Caller

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Kerry

So Mann just admitted to noble cause corruption.

MarkW

Admitted it? He’s proud of it.

J Mac

It is his core principle.

Louis Hooffstetter

Liberalism 101: The end justifies the means.

mike

The Piltdown man 2.0 needs to move from Penn State to the state pen for fraud and taxpayers money refunded.

This is what we are up against. People lie for 20 years and show no indication of ever changing.
Andrew

knr

his got a very good career out of it , so why should he change ? And that is before we talk about ‘any’ ability he has to actually practice science.

Have you ever known a leftist to recant an ideological lie?

Bad Andrew,
You write,
“This is what we are up against. People lie for 20 years and show no indication of ever changing.”
YES!
In 1998 Mann, Bradley and Hughes published their paper (MBH98) that provided the first of Mann’s Hockey Stick graph, and I then immediately saw it failed the ‘smell test’.
As reported on ‘Watts Up With That’ here
https://wattsupwiththat.com/2014/05/12/a-mann-uva-email-not-discussed-here-before-claims-by-mann-spliced-and-diced/
Climategate revealed an email from Michael Mann in 2000 which refuted a complaint at his ‘Hockey Stick’ graph that I had made. Mann’s leaked email mine was in response to Chick Keller having copied an email from me to him. Both emails are included in the article at the top of the link.
My email included,
“>>It is historical revisionism to assert that the Little Ice Age and Medieval
>>Warming did not happen or were not globally significant. It will take much,
>>much more than analyses of sparse and debatable proxy data to achieve such a
>>dramatic overturning of all the historical and archaelogical evidence for
>>the Little Ice Age and the Medieval Warm Period. Those who wish to make
>>such assertions should explain why all the historical and archaelogical
>>evidence is wrong or – failing that – they should expect to be ridiculed. “
I stand by every word I wrote in that email , and I regret that so little ridicule has been applied to Mann and his Hockey Stick.
Mann’s email to Chick Keller said in full,
“>Chick,
>
>This guys email is intentional deceipt. Our method, as you know, doesn’t
>include any “splicing of two different datasets”-this is a myth perptuated
>by Singer and his band of hired guns, who haven’t bothered to read our
>papers or the captions of the figures they like to mis-represent…
>
>Phil Jones, Ray Bradley, and Malcolm Hughes dispelled much of the mythology
>expressed below years ago.
>
>This is intentional misrepresentation. For his sake, I hope does not go
>public w/ such comments!
>
>mike”
Well, I did “go public” and I am now doing it again here, but the execrable Mann has failed to make good on his threat. His failure to fulfil his threat until now is a shame because if the litigious little oik were to attempt to make good on his threat then my terminal prostate cancer would probably prevent me concluding any response (and I want to bury whatever remains of his reputation because his ‘Hockey Stick’ and its purveyors have trashed the reputation of real science.).
Richard

paul courtney

My fellow Courtney: I am deeply sorry to see the word terminal. I am grateful for your steadfast opposition to the execrable one and his phony science (he has diminished the reputation of science, simply put, and science should sue him for going public). You also proved to my satisfaction that M. Thatcher started this whole CAGW game, which I did not believe until you proved it. So I learned from you, and appreciate it.
Apologize for my fellow americans who reflexively argue that socialism has always failed, but we’re trained that way. Not exactly trained, but we get it alot. I know this, because when we bitch about “socialized medicine” in our VA (Veteran’s health care) and Medicare/Medicaid (health care for elderly, poor), an objective observer might point out that it’s socialized AND IT HASN’T FAILED YET. I add YET to keep my conservative credentials in order, and I think socialism is not the best “ism” but that does not diminish my opinion that you are one of the finest Courtneys to post here (top three, certainly).
I think you are correct, BTW, that Nasis (don’t moderate me, bro) were not socialists. The name worked for their program (1. fool people to obtain power; 2) use power to murder, start with enemies, then friends). Like russian communists. Left/Right kinda loses meaning when the program is to murder your own people. Socialism may be economically weak, but the program doesn’t involve murder untless thoroughly corrupted. Been meaning to catch one of your posts to say these things, and say thanks for your work.

richardscourtney

Paul Courtney.
Thankyou.
Richard

Bruce Cobb

Mikey Mann is part of a “noble cause” in the same way that Charles Manson was.

The Deplorable Vlad the Impaler

Cue Kristi in 3 … 2 … 1 …

Kristi Silber

Who the he11 cares about all this? You’re a bunch of vultures, eating a dead horse.
M&M, prof of econ and a mining exec, go after paleoclimatolgist trying to debunk his research. There was a statistical error or some sort, but NAS thought it not a big deal. I’m going with the latter. You all go with the others. So what? It’s done. There are other datasets, other analyses.
Or are you all bent of keeping this alive because it’s the only scandal (about the AGW crowd, anyway) you’ve got in half a century of climate science? Oh, no, there are plenty of CRU scandals to interpret from the emails if one is inclined.
And that means all mainstream climate science is corrupt and untrustworthy. I see.
Someone like C. Monckton, though, he’s a paragon of honesty and virtue?
And no skeptic scientists ever tried to circumvent the peer review process?
No skeptic scientists have ever failed to disclose conflicts of interest?
Nor have any skeptic scientists made blanket assertions or sly innuendo suggesting mainstream science is untrustworthy, biased or corrupt, I suppose?
One random point I’d like to make is that “denier” has nothing to do with the Holocaust. Another straw man. It’s because climate change deniers deny the evidence. “Skeptic” is not a fitting term for all those who disagree that AGW is a problem.
There you go, Vlad.

Thomas Homer

You Mad Bro?

The Deplorable Vlad the Impaler

Posing the question I asked (comment #270 on the earlier ‘hockey stick’ post) in the previous thread:
“For Ms. Silber:
Suppose we start with this: the original thesis of Mann et al, was that the annual growth rings of trees are solely a reflection of the temperature of the environment in which they live (or lived), hence the coining of the term ‘treemometers’ on this site.
Do you, as an ecologist, support this belief, unconditionally? Since I do not want you ‘ … wasting … ‘ any more time here at WUWT than necessary, a simple “yes” or “no” will suffice.”
End of opening thesis.
The remainder goes on for quite a while. I’m not expecting you to read it.
Regards to all,
Vlad (The Mostest-Deplorable-est Impaler-est, the biggest bully-est, and an even bigger-est crashing bore-est, according to C.T. at JoNova)

MarkW

Typical Kristi. Declaring that unless one is a member of the anointed, you have no right to criticize someone who is.
Typical appeal to authority, while also proclaiming the right to determine who is and isn’t an authority based on nothing more than whether she agrees with the person or not.
I also notice that instead of actually dealing with counter arguments, she tries to discredit the entire skeptical movement by claiming that some members of the skeptical movement must be unclean. Heck, she can’t even come up with specific examples.
Then again, given her bogus degree, it’s highly unlikely she was ever required to actually think, just regurgitate what she’d been fed by her professors.

joe - the non climate scientist

“those who disagree that AGW is a problem.”
I for one completely agree that AGW is a problem. I suspect that most, if not all the commentators here likewise agree that AGW is a problem.
The issue is how to tease out how much of the warming is attributable annothropic vs natural. The warmists take one factor that has a reasonably moderate to high correlation to temps over the last 75-150 years vs having almost zero correlation over the last 100m years and pronounce the sole cause of the warming as being annothropic.
The warmists have yet to explain how going from approx 280 ppm CO2 to approx 281ppm CO2 circa 1850 cause a shift from the cooling cycle to the current warming cycle. The warmists fail to acknowledge that the shift was a greater warming shift than the rate of warming from 1979 through the end of the century.
It doesn’t help the warmists credibility by creating and continuing to defend the HS. yes we know that it has been replicated numerous times. Though the replication is done with many of the same proxies and similar methods
Your response indicates you are not familiar (or ignore) the ex-post data selection / exclusion of valid proxies and the excess over weighting of proxies (or the under weighting of proxies) such as dome C (mann jones 2003) Gergis and pages 2k , law dome. mt reed, okasis swamp, Dome C. etc

Kristi Silber

Vlad,
No.

MarkW

Then Kristi, you have joined the ranks of us skeptics.
Regardless, How can you say that 0.7C temperature increase over 150 years is a problem? Especially when most of it wasn’t caused by man. (Which should be obvious to anyone since most of it occurred prior to the big build up in CO2 levels.)

The Deplorable Vlad the Impaler

Either way you answered, I would accept. This is your field, not mine. But MarkW is correct: what is it about Mann’s temperature “reconstruction” that puts such a bee in your bonnet?
My regards and salutations to all,
Vlad
(and, I’m dying of curiosity: did you mean ” … (b)eating a dead horse … “?; truly, I’m serious; I’m just asking if we are looking at a typo, which is my sincere hope)

Kristi Silber

Vlad, you didn’t answer MY question, Why do you keep this alive? Why harp on it forever? It’s such a cliche!
You know, scientists mess up. It’s true. They are human. Some are arsholes. Some are egotists. Some are not as bright as others, though generally they have to be pretty smart to make it through grad school. And scientists mess up. They make mistakes! Some may not ever admit it. It happens.
But that doesn’t mean that they have committed fraud.
It doesn’t mean they are bad scientists.
It doesn’t reflect on the field as a whole.
Science has a way of ridding itself of errors. It takes time, but it happens. It’s not through targeting someone else’s science, trying to find something wrong. If McIntyre and McKitrick saw from the publication that the analyses were faulty, they were right to write a rebuttal. Did these guys know enough about dendrochronology to know from the paper that there was something wrong, given the information that was presented? Or was it a fishing expedition, hoping to find something to discredit this very influential graph? Doing so would be a big score for the skeptic movement. M&M did not try to analyze the data set using proper techniques to see what came of it, it was a simply destructive exercise. It was politically motivated science. Maybe it’s right, maybe wrong, but that’s not really what’s important here.
There are professional standards of behavior, including what James Cook U called “collegial” ethic in the Ridd case. This would include things like sharing of data, doing unbiased peer review, disclosing any conflict of interest, and keeping political and personalities out of science – the process, interpretation and communication of it. And one extremely important ethic is maintain the public’s trust in science. This means critiquing it, too – only through self-criticism can the scientific community identify and fix problems. It is a sign of strength to find and fix mistakes, and one benefit of climategate was that data became much more easily available.
Many skeptic scientists intentionally try to discredit mainstream climate science. Sometimes it’s obvious (Monckton’s “totalitarian”), sometimes it’s subtle (Judith Curry’s Congressional testimony talks about the sorts of bias that could potentially afflict scientists, without directly accusing them of biased science), but it’s not professional. Identify specific problems (peer review, p-hacking, lack of transparency that can be fixed) but don’t tell the public science can’t be trusted. That is anti-science.
That is why we are in this mess.

Kristi Silber

I’ve another comment awaiting moderation.
The prop’ganda machine has been at it since Kyoto. The American Petroleum Institute launched its Global Climate Science Communications Team in 1998. “The plan includes a multimillion dollar, multi-year budget to install “uncertainty” in the public policy arena. Target audiences are detailed including media, policy makers and science teachers….
“The other companies and front groups involved with the plan included:
“Southern Company
Chevron
John Adams Associates
Science and Environmental Policy Project
Committee for a Constructive Tomorrow
The George C. Marshall Institute
Environmental Issues Council
Frontiers of Freedom
Americans for Tax Reform
The Advancement of Sound Science Coalition
Funding sources were identified as American Petroleum Institute (API) and its members; Business Round Table (BRT) and its members; Edison Electric Institute (EEI) and its members; Independent Petroleum Association of America (IPAA) and its members; and the National Mining Association (NMA) and its members.”
From original memo about the plan:
“Unless ‘climate change’ becomes a non-issue, meaning that the Kyoto proposal is defeated and there are no further initiatives to thwart the threat of global change, there may be no moment when we can declare victory for our efforts.”
The first on the list of tactics:
“Identify, recruit and train a team of five independent scientists to participate in media outreach. These will be individuals who do not have a long history of visibility and/or participation in the climate change debate. Rather, this team will consist of new faces who will add their voices to those recognized scientists who already are vocal.”
http://www.climatefiles.com/exxonmobil/1998-global-climate-science-communications-team-action-plan/
This is, of course, after the industry’s own scientists confirmed that AGW was a problem.
This link shows ads and other prop’ganda materials. Sherwood Idso, Patrick Michaels, Robert Balling and Rush Limbaugh all played active roles. It’s about the plans of the Information Council on the Environment (also known as Informed Citizens for the Environment) or ICE, which was formed in 1991 to “reposition global warming as theory (not fact),” and contains letters from the Edison Electric Institute.
http://www.climatefiles.com/denial-groups/ice-ad-campaign/

Kristi Silber

Vlad,
“(and, I’m dying of curiosity: did you mean ” … (b)eating a dead horse … “?; truly, I’m serious; I’m just asking if we are looking at a typo, which is my sincere hope)”
I meant “eating.” I said you were vultures. It’s a play on words.
MarkW,
You think you found a sore spot, a button to push, didn’t you? You love to attack my education. You end up just sounding jealous. You can do nothing to take my education and experience away, so get used to it.
It’s really very weird that Mark attributes my ideas to my professors. I remember a class period spent on climate change, but I’ve no idea what was said. It was decades ago, and the science has come a long way. Nor do I get my ideas from TV, since I don’t watch it. No, most of my ideas I have through interacting with skeptics and investigating their claims. I used to hang out at Breitbart, and it didn’t take me long to see how often publications were misinterpreted, excepts cherry-picked, and the kind of politicized, hate-filled rhetoric that is spouted by some deniers. Not all, though. There have been some very interesting scientific conversations, and I’ve learned a lot about climate and its measurement, modeling, etc – but there’s much I don’t know. I can see things from the skeptic viewpoint. I know most of the arguments, though there are always new ones.
It’s been astonishing how certain so many people are that the Left is evil, corrupt, totalitarian (and/or fascist) and socialist/communist/Marxist. There are some vicious people out there, people who talk about killing their countrymen. When did liberals become leftist (not the same as the Left) totalitarians, and why didn’t I notice? Was that the day Republicans became deplorable? They’re ALL ridiculous epithets.
How can anyone love America and hate half her people?
(Sorry, got a little off-topic there. I wasn’t referring to anyone in particular here.)

The Deplorable Vlad the Impaler

Let’s see: you asked, “Why do you keep this alive?”
Short answer: Personally, I could care less about Mann, his fraudulent science, and since you disavowed the use of treemometers, I have no interest at all in his “reconstruction”. Just for the record, this is NOT my blog; I am a guest of the host, who graciously allows me to post here, at his discretion.
I think Mann, and just about everyone who is a modern ‘warmist/alarmist’ is a fraud, but the problem is, if they get their way, everyone will suffer.
Equally, I might add.
If they stop pushing their agenda, then we can stop fighting. There are very serious, and very real, problems in the world, that could be addressed, if the CAGW camp would stop imposing their “values” on every one else. The problem is not CO2 in the Earth’s atmosphere; the problem is this: we need to develop energy resources everywhere, and make energy inexpensive, abundant, and reliable. People (everywhere) need food, shelter, medical care, clean water, and gainful employment. Energy: cheap, reliable, expandable energy brings wealth wherever it is applied. In copious amounts. The sooner the better (for everyone).
CO2 is not the problem. Warmists are.
Regards,
Vlad

Kristi Silber

Joe, the non-climate scientist,
“The warmists take one factor that has a reasonably moderate to high correlation to temps over the last 75-150 years vs having almost zero correlation over the last 100m years and pronounce the sole cause of the warming as being annothropic.” Few scientists say we’re the sole cause of warming. I don’t know about the last 100m years, but for hundreds of thousands of years CO2 and temperature have been correlated. This is an excellent video talking about the lag of CO2 behind temperature when coming out of a glaciation:

‘The warmists have yet to explain how going from approx 280 ppm CO2 to approx 281ppm CO2 circa 1850 cause a shift from the cooling cycle to the current warming cycle.” ??? Um, I don’t think anyone argues that.
“The warmists fail to acknowledge that the shift was a greater warming shift than the rate of warming from 1979 through the end of the century.” ???
“It doesn’t help the warmists credibility by creating and continuing to defend the HS. yes we know that it has been replicated numerous times. Though the replication is done with many of the same proxies and similar methods”
Yeah, really? The same proxies, bristlecone for bristlecone? Or tree rings, ice cores, corals, sediment cores, carbon dating…that kind of stuff? What do YOU propose to use? Dendrochronology is still used, yes, and it is still a very useful tool for some purposes. It’s not just width of rings that is analyzed; the chemistry is also revealing. The pattern in the rings is clear enough that you can match them tree-to-tree, so you have overlapping records going as far back as you can find appropriate trees. I imagine they can often be fixed to a particular year, since large volcanic eruptions show up in different types of proxies – they are the “anchors,” I suppose? Is that right? (Evidently there are some 40,000-year-old kauri pines in NZ that are being “mined,” destroying a phenomenal record. I just read that today, can’t remember where.)
“Similar methods” – statistical, you mean? Well, that’s not a problem if the method was right before, even if something was done inappropriately. After all this time and all the replications, would it be so astonishing that they were doing it right? Or is it part of the conspiracy – “Let’s each of our groups do this independently and all do it wrong just to come up with the right graph to show the public”?
“Your response indicates you are not familiar (or ignore) the ex-post data selection / exclusion of valid proxies and the excess over weighting of proxies (or the under weighting of proxies) such as dome C (mann jones 2003) Gergis and pages 2k , law dome. mt reed, okasis swamp, Dome C. etc”
I don’t know about those instances, but I’ve a good grip on scientific methodology, which varies in different fields and with different types of data. What may be inappropriate in some circumstances if not always so. For example, if you were doing preliminary data exploration (which is sometimes necessary to test your statistical assumptions as well as make sure your data is free of obvious problems ) and found that 45 proxies agreed and one was way off for part of the record, that would be a clear outlier and you could legitimately remove it from your data set. Of course, you don’t run a test again and again with different subsets of proxies to find which fit your hypothesis – but you know that. Anyway I don’t know the incidents to which you refer, no.

joe - the non climate scientist

.” Kristi Silber-
Your response to the following indicates that you should get up to speed in the issues associated with the HS and the supposed repeated replications of the HS
My comment – “Your response indicates you are not familiar (or ignore) the ex-post data selection / exclusion of valid proxies and the excess over weighting of proxies (or the under weighting of proxies) such as dome C (mann jones 2003) Gergis and pages 2k , law dome. mt reed, okasis swamp, Dome C. etc”
Kristi’s response – “I don’t know about those instances, but I’ve a good grip on scientific methodology, which varies in different fields and with different types”
ClimateAudit.org is an excellent place to start – it is an actual scientific website vs and advocacy website such as Skeptical science.
https://climateaudit.org/
https://climateaudit.org/2016/08/03/gergis-and-law-dome/
https://climateaudit.org/?s=gergis
https://climateaudit.org/page/2/?s=gergis
McIntyre is probably the leading expert on paleo proxies and statistical analysis. He is also a former peer reviewer for the paleo science, though he is no longer used due to the multitude of errors he has pointed out.
You should become familiar with his work.
The following comment from you indicates that you have not attempted an honest assessment of the issues he has pointed out.
Kristi’s comment – “Science has a way of ridding itself of errors. It takes time, but it happens. It’s not through targeting someone else’s science, trying to find something wrong. If McIntyre and McKitrick saw from the publication that the analyses were faulty, they were right to write a rebuttal. Did these guys know enough about dendrochronology to know from the paper that there was something wrong, given the information that was presented? Or was it a fishing expedition, hoping to find something to discredit this very influential graph? Doing so would be a big score for the skeptic movement. M&M did not try to analyze the data set using proper techniques to see what came of it, it was a simply destructive exercise. It was politically motivated science. Maybe it’s right, maybe wrong, but that’s not really what’s important

paul courtney

Kristi: So the NAS said no problem, why would you call it a scandal? You rip Mark for questioning your education (he’s not gonna take THAT from you, you’re so brave!) but it’s ok for you to question the education of M&M (“prof of econ and a mining exec”, well you can’t take THAT from them!). And your final random point (not so much random as the clear signal of a mind that can’t or won’t focus) tells us you think you’re the Pope of lexiconville. Sounds like you’ve made a real study of this, maybe you can tell us who first applied the word “den!er” to climate sceptics and give us the context. No, thought not. Anyway, thanks for once again demonstrating that reasoned argument is just not an arrow in your quiver.

Tom Halla

Mann and his hockey stick doesn’t pass the sniff test, as history, which gives another set of proxies for temperature, contradicts his graph. The Chinese did a major study on their own records, and the LIA was present in northern China.

Ron Long

Right Tom, Mikey et al disappeared the LIA and then utilized “Mikes Nature Trick” to make the hockey stick. Speaking as a person who actually took money from a large oil company (everyone should know the thrill at least once of being paid more than you are worth!) the test of Reality is waiting for us all. What does Mikey think about ClimateGate? Oops!

Mike Menlo

So where is the “definitive” “correct” graph covering the last few millennia? Why don’t you post that instead of repeatedly posting the erroneous graph? Haven’t you heard of “availability cascade?”

michael hart

That is a bit like being shown a drawing of the Minotaur, and then asking to see the actual real creature. The question as such is ‘wrong’.
Mann mixed data that shouldn’t be mixed, unless one is aiming to deceive. The different methods don’t have complete data for the entire time period and it seems no one is willing to now go back and get better, more complete, and up-to-date tree ring data. It would be very interesting from both a scientific and sociological point of view. But Mann chose to not even use all the most recent data that was available, because some of it told the wrong story. The whole field is probably now so poisoned that even an honest researcher would be risking their career by attempting to produce an updated ‘correct’ graph using dendrochronology.

MarkW

Beyond trying to use proxies that were ill suited for the task, and the dodgy statistical techniques, there is also the problem that most of the proxies aren’t yearly, their resolution is decadal or longer.
Then comparing these to a record that does show yearly changes is invalid from the get go.

I quite like this one for the current interglacial based on GISP2. Perhaps someone can tell me what is wrong with it, why deny this and prefer Mann’s mix, match and season to taste fraud on the facts Piltdown science. I am puzzled as to why some pretend it is not common currency when it is one of a number of public domain climate change entry level foundation graphs of temperature anomalies. Not sure if it pre dates the Mann fraud, which it clearly shows to be wrong, as of course does the written history of the climate, from when that was available, and the archeological records.
comment image?dl=0

Or perhaps this version of GISP2 for the Interglacial based on 2004 data.comment image?dl=0

rwisrael

I did it for the good of mankind, because I know what’s good for mankind. Nothing like humility.

MM seems to live in a parallel universe.

Bruce Cobb

Also a place where the sun never shines.

Leo Smith

Oh but it does. Just not on a place he can see it….

Latitude

…something useful for Mueller to do

joe - the non climate scientist

“3/ in our papers, we did not take a position on modern warm period vs medieval warm period. We pointed out gross errors in Mann’s methodology, defects in the most critical proxies, and false claims about skill and robustness (what Mann called his “dirty laundry” in a CG email)”
McIntyre’s work should be commended
I find the climate audit website one of the most honest, sticking to the science, McIntyre doesnt allow the off topic rants that you find at the activists sites or that you find here.
One of the claims by the warmsist is that MWP was regional and only emcompassed the North Atlantic and europe.
SM has pointed out numerous proxies that had ex post data selection/exclusions from gergis and pages 2k which show elevated mwp. such as mt reed, dome c law dome etc. yet were excluded from pages 2k gergis and underweighted in mannjones 2003.

Steve Zell

Mann used tree rings as his temperature proxy, conflating wide tree rings (fast growth) with high temperature. But does a tree grow faster during a hot, dry summer or during a cool, wet summer? Some trees lose their leaves in August if the summer is too dry, but will hold green leaves through October in a wet year. Tree ring widths should be more correlated with warm-season precipitation than temperature, and they say nothing about winter climate, when deciduous trees are dormant.
Mann also found that the proxy tree-ring widths were actually decreasing in recent years, so he substituted the thermometer records for 1970 – 2000, because they showed an increase in temperature (which showed the trend Mann wanted to show).
Also, Mann’s proxy record prior to 1600 was based on ONE TREE. Whatever the climate may have been for that one tree in its location, that cannot be extrapolated to the entire globe, whose climate may have been greatly different elsewhere!

MarkW

Temperature is only one of many things that impact tree growth.

Jan Christoffersen

Steve,
That’s the irony behind Mann’s claim that his hockey stick has been validated by numerous other studies. If that were so, then those studies also would have identified the tree-ring proxy downturn after 1980 (and after 1961 for Keith Briffa’s Yamal study) in contrast to the rising instrumental record in the last two decades of the 20th century. If effect, those corroborating studies would have demonstrated that Mann’s tree rings were not robust proxies for temperatures.

Mike McMillan

Mann relied heavily on the Graybill-Idso 1993 paper for tree rings, but that paper was a study of CO2 fertilization of strip-bark and whole bark bristlecone pines, not a temperature proxy paper. Both tree types showed increased growth, but only the strip-bark trees showed the hockey stick.
Graybill-Idso paper: http://www.climateaudit.info/pdf/others/graybill.idso.1993.pdf
In 2006, Linah Ababneh redid the Graybill-Idso study, with a much larger dataset, and aware of the criticisms of MBH98 (Malcolm Hughes, the “H” in MBH98 was her dissertation advisor). Her study showed increased growth started back in 1850, long before the big CO2 increase, but doesn’t resemble the MBH98 hockey stick. She equivocates on the treemometer theory.
Ababneh 2006: http://arizona.openrepository.com/arizona/bitstream/10150/193510/1/azu_etd_1878_sip1_m.pdf

Bruce Cobb

20 years is about long enough for a reign of error.

Curious George

Alan Tomalty

Unfortunately Professor Muller has been deluded by the fake surface temperature data that NASA,NOAA and Hadley have put out not to mention the fake Australian and New Zealand temperature data. The main temperature chart that he showed is a prime example. He seems a reasonable man and someone should confront him with this fact.

Jones

Can anyone please tell me what the heck is going on with the Steyn case?
I’ve emailed Mr Steyn directly but no response. Is there some kind of gag-order in place?

Mardler

Stern is a busy guy.
The case is ongoing”……

Bruce Cobb

Wait…..wait, I’m getting a vision. Mikey Mann is in prison garb. And what’s this? Someone is making a shank in the shape of a hockey stick? Bizarre. Wonder what happens next. Oh well, at least he has his “nobel prize”. Maybe that will save him.

The “hockey stick” is destined to become an icon that represents both bad science and trillions of wasted dollars.

M Courtney

Mann’s “hockey stick” graph, first published in 1998, was featured prominently in the U.N. 2001 climate report.

It’s worth remembering how long the science was settled before it was declared unassailable.
Three years.
Three years for a reconstruction of temperatures – proxies – not direct observations, to become “settled science”.
In a court of law hearsay does not become unassailable truth just because it was first gossiped a little after the last Olympics.
Science journalism should try to reach that standard, at least.

Alan Tomalty

Science journalism has lost its way. Climate science journalism didn’t even get to the starting gate of truth.

> When first introduced in 1796, phrenology was the latest advancement in the field of neurology. It was widely accepted, even welcomed, by many practicing neurologists as a powerful diagnostic tool. Phrenologists were even on the winning side of an important scientific debate concerning a central concept of brain anatomy and function. As more scientific methods began to take hold within medicine, however, and the secrets of the brain began to yield to more careful investigation, phrenology became increasingly marginalized. By the end of the 19th century the last vestiges of phrenology were gone from scientific medicine and mainstream neurology, but not gone completely. Phrenology survives to this day as a classic pseudoscience, with dedicated adherents convinced of its efficacy.
> The history of phrenology, and the story of its modern believers, is a classic one in the history of pseudoscience.
https://theness.com/index.php/phrenology-history-of-a-pseudoscience/
Sound familiar?

ossqss

Nice read. Thanks Anthony
I remembered reading this item then it really sunk in how much of a fraud Mann was.
http://bishophill.squarespace.com/blog/2009/9/29/the-yamal-implosion.html

The Yamal issue had nothing to do with MBH.

Louis Hooffstetter

“The Yamal issue had nothing to do with MBH.”
Really, do tell? It seems that biased selection of cores used by Briffa are in part responsible for the hockey stick shape of the temperature reconstruction in MBH 98. If that’s not the case, enlighten us.

“If that’s not the case, enlighten us.”
Perhaps you could explain how the Yamal series was responsible for something in MBH98? It was first published in Briffa 2000.

Phil R

Typical Nick response. Find a post were he can attack one small, nit-picky point and jump all over it.
Nick, people make mistakes, even ones who are interested in topics but not experts. I don’t know ossqss’ or Louis Hooffstetter’s background, but at least they are interested and participating, while you’re being nit-picky and disingenuous.
If you want to attack and ridicule someone, you respond, “The Yamal issue had nothing to do with MBH.”
If you want to engage and educate someone, you should respond, “The Yamal issue had nothing to do with MBH. I think you might be referring to bristle-cone pines.”

Nit-picking trivia. But, when was the Yamal data (numbers and dates and thicknesses) determined?
“Published” is meaningful ONLY if ALL the writers and researchers and editors and reviewers were first, fast, prompt, and ethical.
“Knowledge” of a tree event linking the extra (extended) date sequences would have been sufficient for an unethical author to append data to any sequence. Further, we know by observation of the fault-filled “data” that the “pal reviewers” did not do any credible job, much less a thorough and ethical job.

Dr Deanster

As I recall, the issue with Briffa was that he used the same PC analysis as Mann. …. not the same tree.

Not a nit pick.
being accurate in audits matters

“Typical Nick response. Find a post were he can attack one small, nit-picky point “
I was responding to ossqss, who wrote
“I remembered reading this item then it really sunk in how much of a fraυd Mann was.”
In fact, the link supplied was about Briffa, not Mann. That is not a “small, nit-picky point”.

J Mac

If you’ve seen one hokey stick, you’ve seen yamal.

LdB

The bigger issue you can argue about how you make a nice wiggly line twist and do anything you like but proxies are not accepted in actual proper science because of the underlying danger. The only disciplines that deal with proxies are statistics, philosophy, computer and social sciences.
If I was allowed to use proxies in science I could prove just about anything because I only have to create some belief for the relationship and all hell breaks loose.

“The only disciplines that deal with proxies are statistics, philosophy, computer and social sciences”
And medicine. Just about every test they take is a proxy for something. Creatine for kidney function, enzymes for liver function, etc.
But of course also mercury expansion as a proxy for temperature, even litmus as a proxy for pH, etc, etc. What about a cloud chamber for particle detection?

Joel Snider

Devil’s in the details, isn’t he?

LdB

Medicine has had enormous problem BECAUSE they use proxies, we could have a whole discussion about that.

ossqss

Science by ideology is the issue.
So Nick, this quote would be incorrect then you say?
“Certainly, after its first appearance in Briffa’s 2000 paper in Quaternary Science Reviews, this version of Yamal was seized upon by climatologists, appearing again and again in temperature reconstructions; it became virtually ubiquitous in the field: apart from Briffa 2000, it also contributed to the reconstructions in Mann and Jones 2003, Jones and Mann 2004, Moberg et al 2005, D’Arrigo et al 2006, Osborn and Briffa 2006 and Hegerl et al 2007, among others.”

nn

Today, the hockey stick pointed cold, with a temperature drop from record highs in the 70s to the 30s.

J Mac

RE: “Mann …. used his experience in defending the “hockey stick” to effectively label himself as a martyr for fighting global warming.”
If he is a ‘martyr’, he is the first martyr to be hoist by his own petard.

Robert of Texas

This graph still makes me bow my head in shame for what main-stream science is becoming. Through corruption in major universities and government agencies, it has become an arm of propaganda for progressive agendas.
Thank heavens someone is trying to clean up the EPA.

Alan Tomalty

Yes but when will NASA and NOAA get cleaned up? They both have been falsifying temperature data sets by substituting fake numbers that were not in the same data set of their earlier reports. It has happened more than once. Tony Heller has reported on this many times and can show you 3 different reports each a decade a part that used the same data set but was revised twice in the next 20 years.

knr

The fun part is Mann’s work is only valid if you accept his ‘denial ‘ of past climate change . He is a ‘climate change denier ‘
The many other problems with this work merely add to that , and has a ‘hero ‘ of climate ‘science’ it is made clear that the area is a a bit of a joke , although to be fair it does provide an comfortable home for third rate academics , with massive egos , whose professional practice if it was done by a high school student in a science test would be unacceptable.
The only real question is what color will the bus be that his followers will throw him under to save themselves once the infighting starts . And how soon does it arrive . For as the leaked e-mails shows the quality of the Mann can be shown not in how AGW skeptics view him but how his colleagues do.

Pat Frank

First, labeling the ordiante “Temperature” is itself a lie. Not one of the proxy reconstructions is grounded in a physical theory. All of them are pseudo-science; every single one.
Second, Steve McIntyre got hold of Mann’s “Back to 1400 CENSORED” directory, that showed beyond doubt that Mann’s 1400 verification step did not pass statistical muster. So, Mann knew the Hockey Stick graph was statistically wrong but published anyway. There’s a word for that.
Third Steve McIntyre and Ross McKitrick proved beyond any rational doubt (which doesn’t constrain alarmists) that the non-standard short-centering method Mann used falsely elevated the bristle-cone pine time series into position one among the Principle Components.
Effectively, Mann’s graph promotes the series from one tree into a global temperature.
Fourth, even after 20 years, Mann still refuses to reveal central details of his method. Apparently giving complete methodological descriptions is non-standard in science and required only by bullies and oil companies; *certainly* never by real climate scientists(TM).
Finally, Steve McIntyre showed that every single subsequent fake-temperature paleo-proxy graph producing hockey-stick like results just substituted some other hockey-tree, notably the YAD06 tree. Here’s Ross McKitrisk’s retrospective on the controversy.
Mann has gotten away with fraud only because he has been supported by the US National Academy of Science, the American Physical Society, and NASA GISS under the aegis of Gavin Schmidt, all colluders after the fact in the only capital offense in the sciences.

Alan Tomalty

what about the temperature fraud that NASA and NOAA have been committing? Tony Heller has all the evidence. Looking at Tony Hellers resume is looking at a gold standard resume. Alarmists are afraid of Tony Heller.

Amber

Practicing real science would be a refreshing noble cause . Something the Climate Gate bullies failed to do .

“The Canadians’ 2003 study showed the “hockey stick” curve “is primarily an artifact of poor data handling, obsolete data and incorrect calculation of principal components.” When the data was corrected it showed a warm period in the 15th century that exceeds the warmth of the 20th century.”
Their graph from that link is here:comment image
Apart from the 15th century, there is little real difference between the MBH version and its correction. In particular, in the 20th century HS period, it is virtually identical.
The 15th century peak in the corrected version is ironic, because almost no-one now believes it is right. Most accounts, including those favored at WUWT, now have the LIA well under way by then, and the MWP being from about 950-1200 AD. MBH is often accused of “erasing” the MWP, but the usual notion of MWP does not come within their period.
In fact, the 15th century peak in the correction did not come from amended stat methods, but from the arbitrary exclusion of the main source of data for the period, which was the Gaspé cedars. Without them, there really isn’t enough data to form a curve at all, hence the spurious peak.

Oh Dear Nick – I know this must be a touchy one for you but really!

Pat Frank

From Ross McKitrick’s “What is the Hockey Stick Debate About? (pdf), under “3.3 The Gaspé cedar
“Another oddity in MBH98 is that some series are duplicated within the data base. One of these, the Gaspé “northern treeline” series is included as a separate proxy (treeline #11) but it is also in the NOAMER PC collation as cana036. The data begin in 1404, but the chronology is based on only one tree up to 1421 and only 2 trees up to 1447. Dendrochronologists do not use site data where only one or two (or zero!) trees are sampled. In fact the authors who originally sampled the Gaspé data don’t use any of the data before AD1600. When used as treeline #11, MBH98 listed the start date as 1400 and filled the empty first four cells by extrapolation. The misrepresented start date enabled them to avoid disclosure of the unique extrapolation; the extrapolation enabled them to include this series in the calculations going back to AD1400, rather than withholding it until the AD1450 step.
“We wanted to see what would happen if the Gaspé data were not introduced until AD1450. By rights we could have withheld it until 1600, and only used it once in the data base, but that much alteration to the MBH98 procedure turned out to be unnecessary. Simply removing the pre-1450 portion had a large effect on the final graph, as will be shown in the next section. We wrote up the red noise experiment and significance benchmarking material into a paper which was submitted to Geophysical Research Letters. This series was included in the North American “northern treeline” net work even though the Gaspé peninsula is nowhere near the northern treeline.
“We wrote up the information on the Gaspé cedar and the bristlecone pines and submitted it to Energy and Environment. Both papers were accepted and came out in February 2005.”
Removal of Gaspé was apparently not an “arbitrary exclusion” at all.
And it seems that including Gaspé wouldn’t have produced a usable series in any case. And then those in-filled cells and misrepresented start-date. Such perfect methodological integrity.
What was it that Steve McIntyre began calling you, when you were trying to controvert his hockey-stick work at CA? Oh, yes, “race-track Nick Stokes.” How did he come to choose that, one wonders? Perhaps it was your penchant for truth-telling.
I saw your post at moyhu about my manuscript, by the way, in which you repeated your arguments as though they’d not been falsified. More of the same.

Their basis for exclusion is that there were four missing years. But the Gaspé cedars still provided a large part of the data available in the 15th century. Excluding based on made up notions of perfection just diminishes what is known. And gives a nonsense result.

Pat Frank

From McIntyre and McKitrick E&E 2005 (pdf): “The underlying [MBH98] dataset is based on only one tree up to 1421 and only 2 trees up to 1447. Jones and Mann [2004] point to the need for “circumspect use” of tree ring sites with few early examples. The early portion of the series fails standard minimum signal criteria [e.g. Wigley et al. 1984] and indeed fails the data quality standards Mann et. al. themselves listed elsewhere. The early portion of the series was not used by the originating authors [Jacoby and d’Arrigo, 1989; D’Arrigo and Jacoby, 1992], whose analysis only begins effective 1601. In fact, Jones and Mann [2004] do not use the Gaspé series as an individual proxy and only use the Jacoby-d’Arrigo northern treeline composite when it is adequately replicated after 1601.(my bold)”
So Mann himself, but only later, rejected use of Gaspé-like series composed of only a single tree. And his use of Gaspé ignored the pre-existing quality standards of the field.
Hardly “made up notions of perfection.
The charitable diagnosis for MBH98 is incompetent, and that’s an extreme of charitable giving.

Doug

Mr Stokes, it appears that a U shaped graph is not much of a hockey stick nor is it cause for alarm.

“So Mann himself, but only later, rejected use of Gaspé-like series composed of only a single tree”
No he didn’t. Read your quote – it says that “Jones and Mann [2004] do not use the Gaspé series as an individual proxy”. It is included in the North America PC composite. The whole thing is a PC composite analysis, so whether it is included via a sub-PC or individually makes little difference.
AS to why the originating authors didn’t use 15th C Gaspé, the reason is simple. It was outside the time period of their reconstructions (remember, MBH was the first to go back so far). Their 1989 paper was titled
“Reconstructed Northern Hemisphere annual temperature since 1671 based on high-latitude tree-ring data from North America”
and the 1992 paper abstract:
“Reconstructions from 1682–1968…”
The bottom line is that when you are doing a recon, data even from one tree adds to your information. Removing it reduces information. M&M seem to be making up rules to try to exclude information.

Gerald Machnee

Re Nick:
**The bottom line is that when you are doing a recon, data even from one tree adds to your information. Removing it reduces information. M&M seem to be making up rules to try to exclude information.**
Nick is full of it as usual. Mann was not adding one tree for “more information”. The Bristlecone Pine DOMINATED the series. The case is similar with Yamal. McIntyre pointed out 4 different situations where this occurred and Nick knows it very well. Now he tries to imply that M & M were “making up rules”. More BS here. Nick knows that Mann was the one making up rules or using statistical techniques that were not generally accepted. Nick, go tell this quote at Climateaudit..

Pat Frank

The relevant paper is Wigley 1984, not Jacoby and D’Arrigo 1989 or 1993 (received 1992, Nick, revised 1993).
The title of the 1984 paper is “On the Average Value of Correlated Time Series with Applications in Dendroclimatology and Hydrometeorolopy” in J. Climatol. Appl. Meteorol. 23, 201-213.
Wigley 1984 shows that time series from the core of one tree does not meet the data quality standard. Nor does a series composed from the cores of two trees. The MBH98 construction is obviated up to 1447 on that criterion alone.
Not only that, but McI and McK E&E 2005 shows that Mann’s 4-cell infill back to 1400 materially changed the early part of the final series. That’s obviatiation number 2.
A series from one tree isn’t data at all, when one tree is all you’ve got for a global series.
Jacoby and D’Arrigo in fact did use Gaspé in their two reconstructions. But they only went back to 1671 in the 1989 paper because the shortest series ended in 1663. No infilling back to 1400. Imagine that. The Gaspé series is a stand-alone below 1428 and doesn’t qualify as data.
Likewise, their 1993 reconstruction also used Gaspé. But again the reconstruction went back only to 1683 because the shortest series ended in 1681.
Jacoby and D’Arrigo clearly displayed integrity toward their data that the authors of MBH98 equally clearly lacked.
No matter that the reconstructions themselves had no known quantitative relationship to temperature; like MBH98,99.
Your post is nothing but a misdirection, Nick. It appears you didn’t even consult the papers you referenced.

“when one tree is all you’ve got for a global series”
But they clearly didn’t have just one (or two). M&M took out all the Gaspé data, and still claimed to be able to reconstruct 1400-1450.
“Wigley 1984 shows that time series from the core of one tree does not meet the data quality standard”
Wigley wasn’t laying down standards. But in any case, as said, Gaspé was not the only data group. M&M still produced a recon. It can’t help to remove a subset for too few members; all that happens is that you have less trees for the recon than before.
“Jacoby and D’Arrigo clearly displayed integrity toward their data that the authors of MBH98 equally clearly lacked.”
No. They just had less data. There is no evidence that it was inadequacy of Gaspé that limited them. They just had less in total.

Pat,
“Not only that, but McI and McK E&E 2005 shows that Mann’s 4-cell infill back to 1400 materially changed the early part of the final series.”
No. What they showed is that if you use the 4 missing years as an excuse to remove 46 years of data, it materially changes the result (as also shown in the plot above). That is what they did. What I showed here is that if you simply infill the years, it makes very little difference what infill you choose. MBH reasonably made 1400-1403 the same as 1404. But if you set them to the maximum (or minimum) of 1404-1450, it still makes very little difference. That is because it is only 4 years in average of 50, over several data groups. And you retain the information from the other 46 years.

Pat Frank

The issue of Gaspé is that it should not have been used at all. And that infilling Gaspé materially changed the early portion of the MBH98 reconstruction.
Wigley wasn’t laying down standards.
Here’s what Wigley, 1984 says in conclusion: “We have developed a theory for estimating uncertainties in the average set of correlated time series. … We have applied these results to tree-ring time series and to precipitation time series. … [The method] is a measure of the signal-to-noise ratio as used in dendrochronology [and] allows one to estimate the minimum number of cores required to reduce the loss of reconstruction accuracy to below any chosen threshold level and hence to estimate the maximum useful length of a tree-ting chronology.
That’s pretty much deriving a standard.
M&M still produced a recon.
M&M E&E 2005 showed reconstructions with infilled and as-deposited Gaspé to demonstrate the disproportionate effect the infill had on the reconstruction. That didn’t remove data. It showed the impact of improperly altered data.
M&M GRL 2005 showed the Mannian methodological invention produces a hockey stick from trendless red noise.
Can anyone suppose Mann was surprised? His only surprise was probably that anyone figured out what he had done.
No. They just had less data. There is no evidence that it was inadequacy of Gaspé that limited them.
I wrote that the Jacoby and D’Arrigo reconstructions were limited by the shortest series. Not that Gaspé limited them. J&D had too much integrity to extend their reconstruction using data that could not support it.
Unlike MBH98, who had no compunctions about using bad data to achieve their end.

Pat Frank

M&M E&E 2005 Figure 1 says they used the archived version of Gaspé, which goes back to 1404. They didn’t eliminate 46 years of data.
M&M: “The only difference between the two series is the extrapolation of the first four years in MBH98.
Removal of those four points changed the early reconstruction. The early part of the MBH98 hockey stick included 22 series. Any well-behaved method would not be sensitive to the presence or absence of four points.
Removal of the false short-centering, of course, removed the hockey stick.

Pat,
“And that infilling Gaspé materially changed the early portion of the MBH98 reconstruction.”
Again, they didn’t test infilling, in 2003 or 2005. They made it sound as if they did, but what they actually did was remove a large chunk of data. Truly infilling just 4 years makes very little difference. Here is Ross trying to get around their misleading choice of words.
“M&M GRL 2005 showed the Mannian methodological invention produces a hockey stick from trendless red noise.”
They showed something about what happens to the first principal component P1. That is just a rearrangement – it has little effect when you put everything into a recon, as the plot I showed above demonstrates. If you do it the M&M way, you get exactly the same HS.
But their claim of P1 hockey-sticks used a shonky manoeuvre. They generated 10000 from red noise, but then, unannounced, selected the top 100 according to a “hockey-stick index”. That is, the 100 that most looked like a hockey stick. Then they selected at random from that top 100.

Pat Frank

Thanks for the link, Nick.
Reading the exchange, both Ross and Steve McI point out that it is you who are wrong. They removed no chunk of data. They used Gaspé as archived and with the four infilled points as Mann modified it.
That’s the way I read M&M E&E 2005. There’s really no ambiguity: “Figure 1. NH Temperature Index. Top panel: MBH98 emulation; middle panel: using archived Gaspé version; bottom panel: using centered PC algorithm.
Here’s Steve from the linked page, “It’s one thing for you to do your usual Racehorse stuff to try to justify Mann, but I request that you stop making bogus accusations against us.
That pretty much nails it.
They showed something about what happens to the first principal component P1
PC1 was Mann’s global temperature series, Nick. You know that. Mann’s opportunistic short centering elevated the Graybill strip bark bristle pine series into PC1. You know that, too.
If you do it the M&M way, you get exactly the same HS.
M&M E&E 2005 Figure 1 panel 3, which was done the proper way, purports the 15th century as warm as the 20th. Oops.
I use purports by the way, because the whole paleo-temp recon business is no more than pseudoscience. Here and here.
M&M GRL 2005 Figure 3 shows that when Mann’s series are combined using proper methods, the hockey stick becomes utterly trendless. A flat noisy line from 1400 right through the 20th century.
There was nothing “shonky” about anything they did. They showed that Mann’s short centering produced hockey stocks from trendless red noise 99% of the time. Then they displayed an example.
You’ve got no case, Nick. None whatever.

Pat,
“They used Gaspé as archived and with the four infilled points as Mann modified it.”
That is certainly the impression that the text in their paper conveys. But it is wrong. You’ve been misled. Ross let the cat out of the bag in the section you quoted above:
“We wanted to see what would happen if the Gaspé data were not introduced until AD1450. By rights we could have withheld it until 1600, and only used it once in the data base, but that much alteration to the MBH98 procedure turned out to be unnecessary. Simply removing the pre-1450 portion had a large effect on the final graph, as will be shown in the next section. “
Jeans S sums it up clearly:
“it means that Nick Stokes just confirmed what Steve and Ross have been saying last 10 years: if you (a) exclude Gaspe series from AD1400 network (as it should since it starts AD1403) (b) use PCA correctly (which downweights the few bad apples (bristlecones)), you obtain a “striking divergence” from the MBH98 results.”
And that is what they did, and plotted. The mechanism, as I showed in the code (not disputed), was that they replaced the four infilled years 1400-1403 with NA, as disclosed. Should be harmless with a proper treatment of missing values. But what they actually then did was to incorporate in the code a provision that any 50 year segment that began with a NA was excluded from the “roster”. That means, excluded from the analysis. That makes a radical difference. They claim that this is following a MBH rule, but MBH stated no such rule. They claim they can infer it. But no rational rule would exclude a set based on the first year of the 50 yr segment being missing, but with NA’s in any other year allowed. Their “rule” was invented for just one purpose – to exclude Gaspé.
“There was nothing “shonky” about anything they did. They showed that Mann’s short centering produced hockey stocks from trendless red noise 99% of the time. Then they displayed an example.”
Then why did their code select (with no disclosure) the top 100 of 10000 by hockey stick index (appearance), from which they chose the example. And from which Wegman selected 12 examples, to show the better known display of HS-like results?

Pat Frank

Nick, you’re displaying apples and called them oranges. E&E 2005 Figure 1 shows the 15th century effects of using the archived version of Gaspé, and compares that with Mann’s 4-point infilled version.
There just is no doubt about that.
M&M also did a test to see what happens if the pre-1547 part of Gaspé is excluded, based on the fact that the early 15th century data contained only 2 series. Namely, fewer series than is typically recommended for a valid recon.
You’re calling up the later test and using it as a supposed refutation of the earlier test. M&M did both tests. So what? There’s nothing shonky about that.
The 10,000 series were described in the GRL 2005 article. So, they did 10,000 simulations using trendless red noise, of which 99% produced PC1 hockey sticks when the MBH98 method was applied. That’s 9900 PC1 hockey sticks. They then offerred 100 of these 9900 as representative examples. So, what? That’s not shonky at all.
They’re completely upfront about what they did. GRL 2005: “Computer scripts used to generate simulations, figures and statistics, together with a sample of 100 simulated ‘‘hockey sticks’’ and other supplementary information, are provided in the auxiliary material.” And that SI is here: ftp://ftp.agu.org/apend/gl/2004GL021750
You’re stitching up a case made of nothing.

MarkW

Aside from the fact that this graph totally destroys the notion that there is nothing unusual regarding modern temperatures, it’s practically identical to Mann’s work.

“it’s practically identical to Mann’s work”
Yes. And yet McKitrick says that they were “misleading readers with biased methods and bad data”. Apart from the question of whether the criticism is justified, how can it be misleading when the corrected result is so similar?
As to modern temperatures, no-one thinks proxies are a preferable measure of that. The original HS graph shows, rather prominently, the proxy curve terminating in the same way as the M&M graph. The hockey stick shows the contrast with the instrumental rise since 1950 compared with the stability of previous centuries.

” this graph totally destroys the notion that there is nothing unusual regarding modern temperatures”
The graphs do no such thing.

Gerald Machnee

Nick:
**how can it be misleading when the corrected result is so similar?**
Because they are both WRONG!

Bertrand

Thankyou for clarifying this Nick- your posts are very informative. It seems that the hockey stick is indeed valid.

MarkW

So a graph that shows it’s been warmer in the past proves that the current temperatures are unusual?

Ill Tempered Klavier

What has been shown is that to get anything like the “hockey stick” you must use eithervery carefully selected data, dodgy statistical methods, or, as Dr. Mann did, both.

paul courtney

Sorry to be late, would like to see Nick Stokes explain this- Infilling 4 of 50 years is too small a group to affect result. But pulling one gaspe tree (or is it 2?) out of Mann’s grand set of PC proxies is not a small effect, creating a huge upshot around 1500 and falsifies the notion that today’s temp rise is “unprecedented” (isn’t that how you like to say it?). Of course, that result is obviously invalid, in fact 1500 is too late for the MWP. I get that, but doesn’t that prove the invalidity of Mann’s whole approach? Isn’t that what M&M have really established (among other things)? In fact, this point has been made to you and you avoid it by heading around the track for another distracting lap. Racehorse indeed.

ironicman

‘… the MWP being from about 950-1200 AD.’
That is true.

Peter Morris

He’ll get his in the end. The Hockey Stick will be relegated to the trash heap of scientific history with cold fusion, Piltdown Man, and other frauds.
It won’t even have the luxury of being in the “wrong” camp like luminiferous aether.

Spelling error – should be:
“Piltdown Mann”

RicDre

‘What more noble cause is there than to fight to preserve our planet.’
The fact that our planet will be “preserved” with or without his “help” is irrelevant.

Gary

Still waiting for credible evidence of “industry-funded attacks”…

WXcycles

‘What more noble cause is there than to fight to preserve our planet.”
—-
Maybe Mann is pushing for his Nobel Prize to be awarded now-ish?

Bertrand

“Even McIntyre said subsequent studies have “produced somewhat hockey-stick-ish temperature reconstructions,” but added, “none (NONE) of our specific criticisms of Mann’s methods, proxies, and false claims has been rebutted.” ”
So basically McIntyre is saying that subsequent papers have replicated the hockey stick but there was something wrong with Mann’s methods in his original paper? Is that it?

Ill Tempered Klavier

subsequent studies have shown that if you can stomach using either cherry picked data, bogus statistics, both, you can get a “hockey stick.”

paul courtney

Why ask us? Spend some time at CA and decide for yourself. Or do you prefer others doing your thinking, like Kristi.

Mmmmm … planet preserves … yummy ….

Ed Zuiderwijk

Future historian will judge that the ‘hockeystick’ was not a ‘mistake’ or an ‘artifact of poor data handling’, but that it was a deliberate and dishonest attempt to bamboozle ignorants and politicians into believing that the planet was on the boil and that ‘something drastic had to be done’.

http://wattsupwiththat.com/2009/05/03/climate-science-fraud-at-albany-university/#comment-126075
[excerpt]
Here is further evidence of this deplorable behaviour from the warmist camp, excerpted from an article I wrote circa 2005 and published in E&E:
“Mann eliminated from the climate record both the Medieval Warm Period, a period from about 900 to 1500 AD when global temperatures were generally warmer than today, and also the Little Ice Age from about 1500 to 1800 AD, when temperatures were colder. Mann’s conclusion contradicted hundreds of previous studies on this subject, but was adopted without question by Kyoto advocates.
Scientists opposed to Kyoto have now been vindicated. As a result of a Material Complaint filed by Ross McKitrick of the University of Guelph and Steven McIntyre, Nature issued a Corrigendum in July 2004, a correction of Mann’s hockey stick. It acknowledged extensive errors in the description of the Mann data set, and conceded that key steps in the computations were left out and conflicted with the descriptions in the original paper.”
**************************
Later, the Wegman committee issued a scathing condemnation of the Mann hockey stick conclusions.
We knew Mann hockey stick was wrong all along, but it took Steve McIntyre to show us exactly how it was wrong.
However, it took years for Steve to uncover the truth. Meanwhile, the warmist camp has hatched many new alarmist falsehoods.
Detailed rebuttals a la McIntyre take much longer to prepare than it takes the warmists to fabricate new scary stories.
Better to just assume that everything that comes from the warmist camp is self-serving, alarmist and false. Recent history has shown that there is a 99% probability that you will be correct in this assumption, nine times out of ten.
*****************************
https://wattsupwiththat.com/2017/10/07/the-incestuous-nature-of-the-ipcc-reports/comment-page-1/#comment-2630925
[excerpt]
The Wegman Report fully supported McIntyre’s work and declared that the much-touted (by-the-IPCC) Mann hockey stick was broken.
Excerpts – Wegman Report
The debate over Dr. Mann’s principal components methodology has been going on for nearly three years. When we got involved, there was no evidence that a single issue was resolved or even nearing resolution. Dr. Mann’s RealClimate.org website said that all of the Mr. McIntyre and Dr. McKitrick claims had been ‘discredited’. UCAR had issued a news release saying that all their claims were ‘unfounded’. Mr. McIntyre replied on the ClimateAudit.org website. The climate science community seemed unable to either refute McIntyre’s claims or accept them. The situation was ripe for a third-party review of the types that we and Dr. North’s NRC panel have done.
While the work of Michael Mann and colleagues presents what appears to be compelling evidence of global temperature change, the criticisms of McIntyre and McKitrick, as well as those of other authors mentioned are indeed valid.
“Where we have commonality, I believe our report and the [NAS] panel essentially agree. We believe that our discussion together with the discussion from the NRC report should take the ‘centering’ issue off the table. [Mann’s] decentred methodology is simply incorrect mathematics …. I am baffled by the claim that the incorrect method doesn’t matter because the answer is correct anyway.
Method Wrong + Answer Correct = Bad Science.
The papers of Mann et al. in themselves are written in a confusing manner, making it difficult for the reader to discern the actual methodology and what uncertainty is actually associated with these reconstructions.
It is not clear that Dr. Mann and his associates even realized that their methodology was faulty at the time of writing the [Mann] paper.
We found MBH98 and MBH99 to be somewhat obscure and incomplete and the criticisms of MM03/05a/05b to be valid and compelling.
Overall, our committee believes that Mann’s assessments that the decade of the 1990s was the hottest decade of the millennium and that 1998 was the hottest year of the millennium cannot be supported by his analysis.
[The] fact that their paper fit some policy agendas has greatly enhanced their paper’s visibility… The ‘hockey stick’ reconstruction of temperature graphic dramatically illustrated the global warming issue and was adopted by the IPCC and many governments as the poster graphic. The graphics’ prominence together with the fact that it is based on incorrect use of [principal components analysis] puts Dr. Mann and his co-authors in a difficult face-saving position.
We have been to Michael Mann’s University of Virginia website and downloaded the materials there. Unfortunately, we did not find adequate material to reproduce the MBH98 materials. We have been able to reproduce the results of McIntyre and McKitrick.
Generally speaking, the paleoclimatology community has not recognized the validity of the [McIntyre and McKitrick] papers and has tended dismiss their results as being developed by biased amateurs. The paleoclimatology community seems to be tightly coupled as indicated by our social network analysis, has rallied around the [Mann] position, and has issued an extensive series of alternative assessments most of which appear to support the conclusions of MBH98/99… Our findings from this analysis suggest that authors in the area of paleoclimate studies are closely connected and thus ‘independent studies’ may not be as
independent as they might appear on the surface.
It is important to note the isolation of the paleoclimate community; even though they rely heavily on statistical methods they do not seem to be interacting with the statistical community. Additionally, we judge that the sharing of research materials, data and results was haphazardly and grudgingly done. In this case we judge that there was too much reliance on peer review, which was not necessarily independent.
Based on the literature we have reviewed, there is no overarching consensus on [Mann’s work]. As analyzed in our social network, there is a tightly knit group of individuals who passionately believe in their thesis. However, our perception is that this group has a self-reinforcing feedback mechanism and, moreover, the work has been sufficiently politicized that they can hardly reassess their public positions without losing credibility.
It is clear that many of the proxies are re-used in most of the papers. It is not surprising that the papers would obtain similar results and so cannot really claim to be independent verifications.”
Especially when massive amounts of public monies and human lives are at stake, academic work should have a more intense level of scrutiny and review. It is especially the case that authors of policy-related documents like the IPCC report, Climate Change 2001: The Scientific Basis, should not be the same people as those that constructed the academic papers.”

Dr. S. Jeevananda Reddy

In the first figure — Reconstructed (50 year low pass) shows the sharp linear increase in 1900 – 1950 and there onward it only showed ups and downs with little linearity — only pause condition. According to IPCC global warming component starts from 1950 onward. That means after 1950 there is no realistic global warming.
Dr. S. Jeevananda Reddy

pbweather

Good point Doc.

Bruce Cobb

As shown by Nick, Warmunists have to pull all kinds of tricks and stunts to “show” an “unprecedented warming” after the LIA. Mann (and now, Nick) never met a cherry he didn’t pick. An impressive show, really.
Sadly, for the Warmunists, and though they try to hide this fact, they actually have two hurdles; in addition to “unprecedented warming, they have to show that CO2 is causing it. Problem is, it never has before. Oops.

“Problem is, it never has before.”
No problem – it’s rather obvious. CO2 causes warming if you put a whole lot of it in the atmosphere. That hasn’t happened before.

Gunga Din

Who knew?
In the past and the present, Nature has no effect on the atmosphere.
Past higher levels of CO2 were all Man-made.
Maybe all the trillions of bucks spent to prevent CaGW should have been spent to build a DeLorean so we could go back and shoot that caveman that invented fire?

Bryan A

I thought it was those prior levels of 2000ppm – 7000ppm that tipped the earth so now it is hothouse uninhabitable

Pat Frank

CO2 causes warming if you put a whole lot of it in the atmosphere.
Where’s your falsifiable theory of climate demonstrating that causality, Nick?
That hasn’t happened before.
Except for the ~6000 ppm of CO2 500 million years ago. And about 1200 ppm CO2 100 million years ago.
Also here

If adding or removing a tree changes the output curve, must mean the whole theory of tree rings as currently used is rubbish.

That mann is so full of crap

Since Grove and Switsur 94 till now the glaciological community has rejected en masse the hockey stick, to the extent that it eliminates the LIA. See if you can find a professional glaciologist who does not take for granted a global LIA. –AGF

JimG1

The lie is the very bedrock of the leftist agenda. They use it continuously. And it works with the uninformed and/or ignorant. It has always been and continues to be the case because it works so well with their target audience.

John Bills

Nick Stokes, look where the (paleo) climate science has gone:
this latest PAGES 2k compilation shows that you get a hockey stick no matter what you do to the data
https://climateaudit.org/2017/07/11/pages2017-new-cherry-pie/
https://strangeweather.wordpress.com/2017/07/11/the-hockey-stick-is-alive-long-live-the-hockey-stick/amp/

ResourceGuy

In the not too distant future this one graph could either be part of the dustbin of science history or part of the loyalty pledge for the next over reach administration. It has already been an official logo of an unrepentant UN agency. It could be resurrected as a huge red flag in massive stadium-sized rallies with goose stepping.

Joel Snider

Back when I still believed in honesty, I thought that putting an algorithm in a model that produced the same graph result regardless of inputted data ought to have been sufficient to kill the issue.
Then I read the paper the following day, with the headlined rationalizations to explain it all away – presented by the press as ‘the real story’.
Enough propaganda can apparently bury anything.

Not sure if I posted this version of the current interglacial temperature anomaly – a climate change for beginners graph based on GISP2. The reason no one else has is because , I assume, you need to be familiar with it and the existence of the data series to as a foundation to participate in the discussion? I also assume Mann chose to ignore this assessment of reality from a cotiguous data set as no t the result he wanted. as he also ignored the historical record from people alive and writing at the time of what the actual climate was like, rather than manipulating his disparate proxy data sets. Same basic BS of being told we should prefer to believe partial extrapolations of misweighted and sparse climate models of non-linear effects set out as the certain words of god, heard through his IPCC priests, over the proven physics and the natural data. Really?
Note the bonus graph showing lack of significant CO2 correlation with the temperature change. Either leading or lagging, at this relatively insignificant level of anomaly.comment image?dl=0

“Not sure if I posted this version of the current interglacial temperature anomaly – a climate change for beginners graph based on GISP2”
The usual dishonest stuff, with the end strip marked as “Modern Warm Period” when the last data point was in 1855.

In what way is this “dishonest”? It uses the GISP2 data set to 1855, correct, and the real temperatures from HADCRUT4.4 to show the recent past,.These now overlap back to 1794. Do you suggest HADCRUT 4.4 is wrong or biased in some way? How is adding the real data from Greenland to the ice core readings to show the recent past in comparison “dishonest”?
ftp://ftp.ncdc.noaa.gov/pub/data/paleo/icecore/greenland/summit/gisp2/isotopes/gisp2_temp_accum_alley2000.txt
For another assessment of the Greenland temperature range, using different gas proxies, there is Kobashi, reviewed with links here, Figure 4 seems apposite..
https://andymaypetrophysicist.com/kobashi-and-alley-gisp2-central-greenland-temperature-reconstructions/
This is also tailed with HADCRUT4.4. I don’t see any significant contradictions with my posted diagram, which is widely used, small time and magnitude shifts, yes, but substantively the same warm and cold periods, and nicely illustrating the fraud of Mann’s concatenated disparate data sets with his various “adjustments”, whatever they were, to eliminate the warmer historical periods, make pre industrial climate seem almost invariate, and make the current temperature appear to be higher than the several precedents this interglacial. Also denying the written historical record, of course.
Nothing unusual is happening here, honestly, on the facts.
This the data for Greenland to 2013.
http://www.dmi.dk/fileadmin/user_upload/Rapporter/TR/2014/tr14-06.pdf.