Is the Hockeystick Theory Finally Dead?

  • Thread starter Andre
  • Start date
In summary: I'll skip it. In summary, the author discusses the hockeystick graph and how it has been critiqued. He also mentions how skepticism is an intrinsic part of science, and how it has affected climate science. He finishes the summary by saying that the natural variation is much larger than the hockeystick intended to suppress.
  • #1
Andre
4,311
74
The epilogue.

We have been discussing the hockeystick here over the years now, a few threads:

https://www.physicsforums.com/showthread.php?t=49049
https://www.physicsforums.com/showthread.php?t=61419
https://www.physicsforums.com/showthread.php?t=75609
https://www.physicsforums.com/showthread.php?t=94621

The wrap up of the story very shortly,

In the 1990ies the IPCC wanted to determine the forcing function of greenhouse gasses. But this is hard as the signal is contaminated with natural climate variation. So one of the areas of research was the last millennium, which appeared to be characterized by an early Medieval Warm Period to be followed by a Little Ice Age. Both were obviously not related to greenhouse gas variation and would blur the investigation about empiric greenhouse forcing significantly

However as soon as the IPCC started to work, both those periods started to become doubtful and in the fall meeting of the American Geologic Union in 1998, Overpeck had got rid of the Medieval Warm Period. (Surprisingly it’s no longer on the net, but googling you may find some references to it). To prove that those periods have not existed, Mann Bradley and Hughes (MBH) carried out ‘multiproxy’ studies, reconstruction the climate of the past. The graph of the global temperature of the last millennium, the hockeystick promoted to Fig 1B of the http://www.ipcc.ch/pub/spm22-01.pdf , page 3 which correlated incredibly accurate with the CO2 hockeystick (fig 2a) on page 6.

So, apparently no more doubt, and from the spikes in the last century it seemed obvious that greenhouse gasses have a very dominant role in global temperatures and that natural variability had been very small in the last millennium.

But somehow some people were not convinced of such a construction and these people became known as skeptics. Curiously enough skepticism is an intrinsic part of science, and the core of the scientific method but somehow in climate science it became equivalent to immoral greedy hoodlums. But anyway,

Several attacks were made on the poster child graph, the most persistent being from Steve McIntyre and Ross McKitrick (M&M), who audited the methods, showing that a lot was wrong.
More details here.

Incidentally, the geologic fieldwork continued and evidence of a worldwide Medieval Warm Period accumulated as can be seen http://www.co2science.org/scripts/CO2ScienceB2C/data/mwp/mwpp.jsp . The same is true for the Little Ice Age.

So,two committees looked at the work. The NAS committee agreed with the critique of M&M but confirmed also the dire climate changes brought about by anthropogenic greenhouse gasses. Then the http://energycommerce.house.gov/108/home/07142006_Wegman_Report.pdf for the Barton hearing also confirmed the “errors” in the MBH methodology, as Mann could not defend these “errors” adequately yesterday the hockeystick can be considered death. I wonder how long the burial will take.

It may also be clear that normally the damage for climate science would be considerable, the Third Assessment Report and it Executive Summary hinged completely on the hockeystick and so do numerous other publications. So the natural variation is indeed much larger than the hockeystick intended to suppress. A genuine mistake or a hoax?

It may also be clear that further reference to the Hockeystick as official information regarding climate issues could be subject to nationals laws pertaining integrity and honesty for disclosure of information.
 
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  • #2
When your source makes statements such as these I find them to be suspect.

To bolster our claim that "There Has Been No Net Global Warming for the Past 70 Years," each week we highlight the temperature record of one of the 1221 U.S. Historical Climatology Network (USHCN) stations from 1930-2000.
This issue's temperature record of the week is from Milledgeville, GA. During the period of most significant greenhouse gas buildup over the past century, i.e., 1930 and onward, Milledgeville's mean annual temperature has cooled by 1.15 degrees Fahrenheit. Not much global warming here!
They cherry pick and distort the evidence.

Obviously this site is biased.
 
  • #3
What seems to be the problem? Isn't http://data.giss.nasa.gov/cgi-bin/gistemp/gistemp_station.py?id=425722170040&data_set=1&num_neighbors=1 true?

But you're stealing the thread. This is not about warming or not, this about whether we looking at a honest scientific glitch or a big scam that bullied many contries into a useless treaty that will only costs dearly.
 
  • #4
I was simply pointing out that a source that claims that the Earth has been cooling for the last 70 years, and uses cherry picked data is not going to bolster your argument.

Worldwide, of the 20 hottest years on record, 19 have occurred in the last 2 decades.

[edit]I don't wish to steal your thread, so I will just observe from here on out.
 
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  • #5
Skyhunter said:
I was simply pointing out that a source that claims that the Earth has been cooling for the last 70 years, and uses cherry picked data is not going to bolster your argument.

Worldwide, of the 20 hottest years on record, 19 have occurred in the last 2 decades.

[edit]I don't wish to steal your thread, so I will just observe from here on out.

We've been breaking a lot of records in Alaska this summer, too. But I don't know if it's mentionable (since I don't know our recorded history of temperatures, or how accurate they are.)

In the spirit of keeping with the thread, however, I'd like to opine. I'm (for the most part) completely neutral on the subject of global warming, but I tend to lean towards being suspicious of huge billowing stacks of smoke planted in series, just because, you know, they look ugly...

On the other hand, I'd like to porpose a motive, and see if it relates in any way to reality. How much money would be gained by the U.S. if they enforced this Kyoto Protocol, and then refused to adhere, themselves (which is what I hear is pretty much the situation).

Could this have anything to do with Rumsfeld's and the militairy-industrial complex taking advantage over other countries?
 
  • #6
How about just simply sticking to science, no motives, no anecdotal evidence (BTW there was a all time record cold period in Australia this month..irrelevant) and no ad hominems, (these guys present something I don't believe so they are biased and consequently all the peer reviewed arcticles that they accumated are obviously wrong)
 
  • #7
Andre said:
How about just simply sticking to science, no motives, no anecdotal evidence (BTW there was a all time record cold period in Australia this month..irrelevant) and no ad hominems, (these guys present something I don't believe so they are biased and consequently all the peer reviewed arcticles that they accumated are obviously wrong)

by 'these guys' are you reffering the Mann party?

and by you're wording you've stated that they're biased because they presented something you don't believe.

I can't participate in this scientifically. There are way too many variables in climatology and jargon that I don't understand in the atmospheric journals I read.
 
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  • #8
It's good to know that at least some people have remained on my side of the skepticism fence, despite the "global warming" media blitz we've been experiencing in the last few years. Thanks for doing the research, Andre.

Believe those who seek the truth; doubt those who find it. -- Andre Gide

- Warren
 
  • #9
You're welcome.

Isn't it strange that the passing away of the hockeystick went totally unnoticed in the press? Why would that be?

Anyway another confirmation here:

End of the hockey season

It seemed a bad day for science and truth when the IPCC swallowed the notorious hockey stick graph and published it as fact. The new political and media establishment dutifully took it up and the dogma was unquestionably accepted and imposed on a credulous world. A thousand years of history, science and arts were swept away and declared void, as the well documented phenomena of the Little Ice Age and the Mediaeval Warm Period were suddenly deemed never to have happened. It was Orwell’s Ministry of Truth on a world scale and with horrific effectiveness. The resistance movement was almost entirely confined to the internet.

Enter two heroes, the McCritics. They braved rejection by the once-great science journals, such as the gone-green Nature. They endured vilification by the jackals of the establishment. Yet they staunchly soldiered on. Unlike their adversaries, they boldly published not only their results but also their computer programs. How their opponents crowed when an error was discovered! Yet they ploughed on, proving that the methodology behind the hockey stick was invalid. Still they were ignored and maligned.

Then the US Cavalry appeared over the hill, in the form of the US House Committee on Energy and Commerce. The Committee appointed a group of statisticians of impeccable qualification and independence, under the leadership of Dr Edward Wegman, Professor of Statistics at George Mason University , who chairs the National Academy of Sciences’ (NAS) Committee on Applied and Theoretical Statistics. They have now produced a report that devastatingly demonstrates what we sceptics knew all along, that the hockey stick is pure nonsense...cont'd
 
  • #10
Do you mean the mass media? The general public could never comprehend what is going on. Or if you tried to explain it to them.
 
  • #11
http://www.sciencemag.org/cgi/content/summary/313/5786/421
Science 28 July 2006:
Vol. 313. no. 5786, p. 421
DOI: 10.1126/science.313.5786.421
Prev | Table of Contents | Next
News of the Week
CLIMATE CHANGE: Politicians Attack, But Evidence for Global Warming Doesn't Wilt
Richard A. Kerr
With hockeysticks in hand, U.S. legislators skeptical of global warming fired shots last week at what has become an iconic image in the debate. But their attack failed to change the outcome of the contest.
Apparently somebody didn't hear the requiem.
 
  • #12
Which proofs the vicious circle. It was the hockeystick that tipped the balance between doubts and immenent disaster. Since then nothing has been added as evidence, actually the 1998 spike has never been approached again.

But even with withdrawing the fake core evidence, the vicious circle doesn't need a cause anymore. It's self sustaining now.
 
  • #13
Another example of how to do damage control to save the myth.

Mann et al don't understand the fuzz: that's what they had said all the time, wasn't it?

http://www.climateaudit.org/?p=775

It is hard to imagine how much more explicit we could have been about the uncertainties in the reconstruction; indeed, that was the point of the article!
(but please read the whole blog)

However, not much of uncertainty about the hockeystick in the IPCC TAR http://www.ipcc.ch/pub/spm22-01.pdf#search=%22summary%20policy%20makers%20%22 , when Mann himself was one of the authors:

...New analyses of proxy data for the Northern Hemisphere indicate that the increase in temperature in the 20th century is likely7 to have been the largest of any century during the past 1,000 years. It is also likely7 that, in the Northern Hemisphere, the 1990s was the warmest decade and 1998 the warmest year (Figure 1b)...

7 "likely" being defined as: 66−90% chance;

Now a brilliant exposure of how the myth of consensus is sustained, simply refute anything that challenges it:

http://www.climateaudit.org/?p=782

15 August 2006
Rejected Nature Correspondence
Last week, Mann et al published a letter in the Nature Correspondence section saying that it was "hard to imagine how much more explicit" they could have been about the uncertainties and blaming "poor communication by others" for the "subsequent confusion", disucssed here. The Mann et al letter is absurd and Ross and I decided to submit a short reply to Nature Correspondence, shown below together with Nature’s rejection.

The Steve and Ross Letter

Sir:
In their recent correspondence, (Nature, 442, 627, 2006) Mann et al. claim that "it is hard to imagine how much more explicit we could have been about the uncertainties in the reconstruction" (Nature, 392, 779-787, 1998). In fact, it is not hard at all. They could have disclosed and explicitly discussed the lack of statistical significance of the verification r2 statistic for reconstruction steps prior to 1750, values of which were approximately 0 (S. McIntyre and R.McKitrick, GRL, 32, doi:10.1029/2004GL0217502005, 2005; E. Wahl and C. Ammann, Clim. Chg, accepted, 2006). Such disclosure would have shown that the uncertainties of their reconstruction were substantially underestimated, as the National Academy of Sciences panel recently concluded (p. 107).

Mann et al blame "poor communication by others" for "subsequent confusion about uncertainties", but ignore the fact that Mann was a lead author of chapter 2 of the IPCC Third Assessment Report, which stated that the Mann et al. reconstruction had "significant skill in independent cross-validation tests," without mentioning the verification statistic failures. They likewise ignore their own press releases, issued by the University of Massachusetts, and contemporary press articles linked at Mann’s website, which set the overconfident tone they now apparently regret. There is no evidence that Mann et al made any effort to correct these "poor communications" either at the time or subsequently.

Nature itself must share blame for the length of time it took to identify these statistical failures. In 2003, after Mann et al had refused to provide to us either the test scores, residual series or even the results of the individual steps for independent statistical verification, we filed a Materials Complaint with Nature requesting this data. Nature refused to intervene, saying that disclosure was up to the original authors. Perhaps this experience will encourage Nature to re-consider such policies.

Stephen McIntyre and Ross McKitrick

Within a few days, we received the following rejection letter from Maxine Clark, Publishing Executive Editor:

Thank you for your Correspondence submission, which I regret we cannot offer to publish. The paragraph about "poor communication" does not add substantially to our news report, to which Mann et al. were responding in their letter. Nature has no connection to the press releases you describe. Perhaps you would prefer to communicate directly with Mann et al. on your opinion on these matters, as you letter has more of a tone of a complaint about the authors than of something that Nature readers would find of interest?

Your last paragraph is confusing to us because Nature has already published a correction to this paper containing Supplementary Data, as part of the complaint you initiated. This has closed the matter so far as we are concerned.

Yours sincerely

Maxine Clarke

I suppose that I should have known that it was foolish to expect Nature to give a vestige of equal treatment when it came to climate science...cont'd

Which raises the issue if "Science" is truly a scientific magazine.
 
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  • #14
http://www.sciam.com/article.cfm?chanID=sa006&articleID=00007F57-9CE1-1213-9BEF83414B7F0000&pageNumber=1&catID=2 in Scientific American will make clear how important the dearly beloved hockeystick is. Please also do note the fallacies.

Behind the Hockey Stick
Seven years ago Michael Mann introduced a graph that became an iconic symbol of humanity's contribution to global warming. He has been defending his science ever since

By David Appell

...That stick has become a focal point in the controversy surrounding climate change and what to do about it. Proponents see it as a clear indicator that humans are warming the globe; skeptics argue that the climate is undergoing a natural fluctuation not unlike those in eras past.

But Mann has not been deterred by the attacks. "If we allowed that sort of thing to stop us from progressing in science, that would be a very frightening world," ...

In each case, the outcome was clear: global mean temperature began to rise dramatically in the early 20th century. That rise coincided with the unprecedented release of carbon dioxide and other heat-trapping gases into the Earth's atmosphere, leading to the conclusion that industrial activity was boosting the world's mean temperature. Other researchers subsequently confirmed the plot.

Therefore it was extremely important that the hockeystick got the shape of the hockeystick, in this way the hockeystick was the only (but faked) "evidence" of the high correlation between CO2 and temperature

The work of Mann and his colleagues achieved special prominence in 2001. That is when the Intergovernmental Panel on Climate Change (IPCC), an international body of climate experts, placed the hockey-stick chart in the Summary for Policymakers section of the panel's Third Assessment Report. (Mann also co-authored one of the chapters in the report.) It thereby elevated the hockey stick to iconic status--as well as making it a bull's-eye...

You see? Global warming is the hockeystick. The hockeystick is (should be) dead. Global warming will never die, so the hockeystick can't be dead.

...
That led to "unjustified attack after unjustified attack," complains climatologist Gavin A. Schmidt of the NASA Goddard Institute for Space Studies.

However the NAS and Wegman reports vindicate the critics of McIntyre and McKitrick

For instance, skeptics often cite the Little Ice Age and Medieval Warming Period as pieces of evidence not reflected in the hockey stick, yet these extremes are examples of regional, not global, phenomena.

A gross misrepresentation discussed elsewhere. The hundreds of papers http://www.sciencedirect.com/science?_ob=QuickSearchListURL&_method=list&_aset=V-WA-A-W-YA-MsSAYWW-UUW-U-AACYVUVZBW-AACCEYCVBW-ZEVCVAEU-YA-U&_sort=d&view=c&_st=13&_acct=C000050221&_version=1&_userid=10&md5=d5e7322abd76dd8091e129e41fd3f4f9, do show a different story.

Now it's time for the fallacies. Mainly ad hominems:

"From an intellectual point of view, these contrarians are pathetic, because there's no scientific validity to their arguments whatsoever," Mann says. "But they're very skilled at deducing what sorts of disingenuous arguments and untruths are likely to be believable to the public that doesn't know better."

Mann thinks that the attacks will continue, because many skeptics, such as the Greening Earth Society and the Tech Central Station Web site, obtain funds from petroleum interests. "As long as they think it works and they've got unlimited money to perpetuate their disinformation campaign," Mann believes, "I imagine it will go on, just as it went on for years and years with tobacco until it was no longer tenable--in fact, it became perjurable to get up in a public forum and claim that there was no science" behind the health hazards of smoking...

Recognized all of them? this paragraph only is a priceless example of very skilled demagogery.
 
  • #15
Anyone interested in seeing McIntyre and McKitrick debunked should start here and follow some of the links.

And of course one should follow the money.

http://www.environmentaldefense.org/article.cfm?contentid=3804&CFID=21084385&CFTOKEN=29888831
 
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  • #16
I'm a bit surprised with that post. Not sure what it's all about.

Skyhunter said:
Anyone interested in seeing McIntyre and McKitrick debunked should start here and follow some of the links.

About here, here, perhaps note that it is dated 2004, well before both the North commitee report and the Wegman report both admitting that M&M were right in their assertions about the 'technical' errors in the hockeystick construction.

And of course one should follow the money.

http://www.environmentaldefense.org/article.cfm?contentid=3804&CFID=21084385&CFTOKEN=29888831

And exposing the bankrupcy of the global warming science, when the scientifical arguments have failed, then the last ressort is mud throwing, or ressorting to fallacies like the Argumentum ad Hominem. Ironically enough this shot was aimed badly as well, since McIntyre has refused any refunding of expenses up until this year, when his repeated show ups at those commitee hearings, etc, became too frequent to be financed privately.

One should also observe how very few times this ad honimem is used to other way around by pointing to the securing of research money for the warming gang for more global warming scaremongering. Neither way it contributes to finding the truth. And for those who can see through the fallacy it may indicate, which site of the debate can rely on evidence and facts and which side needs to revert to appeals to subjective nonsense.
 
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FAQ: Is the Hockeystick Theory Finally Dead?

1. What is "Requiem for a Hockeystick"?

"Requiem for a Hockeystick" is a scientific paper written by Michael E. Mann, Raymond S. Bradley, and Malcolm K. Hughes, published in 1998. It presents a reconstruction of global temperatures over the past thousand years, using data from tree rings, ice cores, and historical records.

2. Why is the paper controversial?

The paper's findings suggest that recent global warming is unprecedented in the context of the past millennium, which challenges the beliefs of some individuals and organizations who deny the existence or human contribution to climate change. As a result, the paper has faced criticism and attempts to discredit its methods and conclusions.

3. How is the "hockeystick" graph created?

The "hockeystick" graph is created by combining multiple sources of climate data, including tree rings, ice cores, and historical records, to reconstruct global temperatures over the past thousand years. This data is then analyzed using statistical methods to remove any non-climatic influences and create a smoothed graph of temperature changes over time.

4. What is the significance of the "hockeystick" graph?

The "hockeystick" graph is significant because it provides evidence for the existence of global warming and its acceleration in recent decades. It also shows that current global temperatures are outside the range of natural variability in the past thousand years, indicating that human activities have played a significant role in driving current climate change.

5. Has the "hockeystick" graph been replicated by other studies?

Yes, multiple studies using different data sources and methods have replicated the findings of the "hockeystick" graph, including a 2006 study published in the journal Science. These studies provide further support for the existence of recent global warming and the accuracy of the "hockeystick" graph as a representation of past temperature changes.

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