Reviving the Debate: The Truth Behind the Hockey Stick Controversy

[Andre]

I hope that title is not too adacious. We have been discussing hockeysticks every once and a while here, you know, http://www.grida.no/climate/ipcc_tar/wg1/figspm-1.htm about the alleged global temperatures of the last millenium.

After the repeated debunking of Soon and Baliunas, Hans van Storch, and compared to multiple other reconstructions like Moberg that differ markedly enough from the hockeystick to consider it flawed, we thought we had buried it especially with the serious http://www.climate2003.com/pdfs/2004GL012750.pdf .

So whaddyaknow. a rigorous revival coming up? The replication of the hockeystick is http://www.ucar.edu/news/releases/2005/ammann.shtml. Were all the others wrong after all?

thriller or slapstick?

 

[Andre]

Anyway Steve McIntyre is trying his very best to find out what is new. It may even seem that A&W have succeeded in emulating the M&M05 hockeystick much more than replicating MBH98. He sees the same problems:

I pointed out the particular problem in emulating MBH98 early 15th century results and it’s reassuring to see that WA have exactly the same problem (although their advertising doesn’t disclose this.)

In psychogical terms http://www.ucar.edu/news/releases/2005/ammann.shtml is called demagogy.

 

[Andre]

Anyway, as Spence puts it

"rumours of the hockey stick’s vindication were greatly exaggerated."

 

[emotionalmachine]

That rule only applies to fiberglass sticks, which I may add are priced around a ridiculous $200 CDN price tag.

 

[Andre]

And now the House of Representatives wants to know what's going on.

http://energycommerce.house.gov/108/Letters/062305_Pachauri.pdf

http://energycommerce.house.gov/108/Letters/062305_Bement.pdf

http://energycommerce.house.gov/108/Letters/062305_Mann.pdf

 

[Andre]

But it's not how politics works because this is way past science. Please count the fallacies in this letter:

http://www.democrats.reform.house.gov/Documents/20050701123028-71010.pdf

You can take it the other way around. If the work on the hockeystick was 100% correct, wouldn't these climate scientist with "impeccable records, widely regarded as among the leading researchers", have welcomed the opportunity to give full, true and plain disclosure and proof beyond any doubt how malicious the relentless attacks of those devious climate sceptics were?

 

[hypatia]

I wonder were the answers to these questions made public?

 

[pattylou]

But it's not how politics works because this is way past science. Please count the fallacies in this letter:

http://www.democrats.reform.house.gov/Documents/20050701123028-71010.pdf

I'm sorry, I must be a bit daft. I counted, and only got to (maybe) one, "appeal to authority."

Is the answer one? Thanks for your help.

 

[pattylou]

:

So whaddyaknow. a rigorous revival coming up? The replication of the hockeystick is http://www.ucar.edu/news/releases/2005/ammann.shtml. Were all the others wrong after all?

thriller or slapstick?

I don't follow you. Are you mocking scientists for trying to understand whether warming is best described by a sharp increase in recent years?

The way science "works" is to gather evidence to identify whether a hypothesis can be disproven, or alternatively supported. The goal is to have a better idea of physical processes in our world. The goal *isn't* to say "we're right and everyone else is wrong."

Thank you for the report. I am impressed that the authors invite everyone to look at their code in order to evaluate their methodology.

 

[pattylou]

If the work on the hockeystick was 100% correct, wouldn't these climate scientist with "impeccable records, widely regarded as among the leading researchers", have welcomed the opportunity to give full, true and plain disclosure and proof beyond any doubt how malicious the relentless attacks of those devious climate sceptics were?

uhhh... no? Their purpose in life isn't to do battle with Exxon. They are working scientists who presented evidence that warming has accelerated in recent years. I am sure that they were happy to publish as soon as they had a publishable amount of work. I likewise believe that they are happy to have their understanding modified as work continues by their lab and others. Science isn't static.

And I'm sure that they don't describe themselves as "impeccable, leading scientists in the field." That was politics. You're letting your arguments overlap. I think you might even be guilty of demagogey (sp?).

 

[hypatia]

I don't see a problem with the government asking about the amount funding, asking about methods used..or where the archives are. It seems to me if you made millions of dollars via funding you would of hired a person to organize it all so that this information would be available at the click of a button. It sort of keeps everything on the up and up.
It makes me wonder what/why there hiding.

Its not one or two people challenging the results of Manns means to a end, there is now a whole lot of other science groups looking into it, and asking for more information on his data.

 

[Andre]

and only got to (maybe) one, "appeal to authority."

I know, when you agree with somebody then the fallacies don't show. However I just lost an hours work of listing and explaining bandwagons, strawmans, tu quoiques, Argumentum ad Superbiums, etc.

Perhaps I may refer to the discussion about this in another distinguished forum http://www.ukweatherworld.co.uk/forum/forums/thread-view.asp?tid=22066&start=1 . It may surprise you how many people have their thoughts about the hockeystick there.

Their purpose in life isn't to do battle with Exxon.

I don't understand, I though we would limit ourselves to science. Did anybody mention oil companies? And they don't have to battle, merely share how it was done, getting a paradigm shift through unquestioned (even with flying colors), against the mainstream of multiple detailed research of the past that clearly suggested the existence of a global Medieval Warming Period and a little ice age. this has intrigued a lot of people independent of Exxon.

Perhaps take note of the discussion in Wikipedia

A new reconstruction by Moberg, et al, published in Nature 433, 613 - 617 (10 February 2005) shows both the Medieval Warm Period and Little Ice Age anomalies (although not by name) and concludes that the temperatures around 1000 and 1100 AD were comparable to those of the 20th century before 1990. "Moberg's reconstruction will help to put the record straight in one of the most contested issues in palaeoclimatology," says Hans von Storch. "But it does not weaken in any way the hypothesis that recent observed warming is a result mainly of human activity."[8]. Moberg's results are consistent with those of Von Storch, et al, who conducted a modeling analysis that showed the variability to be about twice as great as previously published [9]Science 306, 679 - 682 (2004).

Mann concedes that past climate variations may be larger than thought, but that "The contrarians would have us believe that the entire argument of anthropogenic climate change rests on our hockey-stick construction...

And the simple question now is if the hockeystick was a mandatory conclusion that was inevitable when considering the data but even then the question remains how it has been possible to slam away (that’s what you do with sticks I guess) the Medieval Warming Period and the Little Ice Age unquestioned.

... But in fact some of the most compelling evidence has absolutely nothing to do with it, and has been around much longer than our curve" [10].

That can only be the ice age idea that we discuss elsewhere. He will be utterly surprised.

 

[pattylou]

Maybe part of the problem here, is that until about a month ago I was unaware of the hockeystick.

Are you saying that Mann fudged data?

If so, then that was very, very wrong.

Are you also saying that therefore the entire warming argument fails?

 

[Andre]

Are you saying that Mann fudged data?

McIntyre and McIttrick M&M's have analysed this and do say so. I tend to see more reasons for them to be right, than for Mann et al. But I realize that this is the standard problem. Who do you want to believe and why? Perhaps read http://www.technologyreview.com/articles/03/12/wo_muller121703.asp of Richard Muller on the correlation between scientific standards and attractiveness of conclusions.

Obviously, reading the papers is not enough, I should scrutinize http://www.uoguelph.ca/~rmckitri/research/trc.archive.html to be sure. But there are obvious limitations. That's why a completely independent, fallacy free inquiry is so extremely important. That should have the final word.

Hence the disgrace of the letter of that congressman.

Are you also saying that therefore the entire warming argument fails?

No that would be another fallacy. Every argument its own problems; there used to be three elements that fuel global warming. The interpretation of the ice ages, that went nowhere however, because of the essential errors. Hence(?), the Hockeystick came to replace it and show “proof” beyond any doubt that the main driver of climate change is CO2 concentration. The third one, obviously, is the general surface warming as experienced in the last decades. This has it’s own fields of problems like accuracy, (under) estimation of urban heat island effect, conflicting satellite- and balloon radio-sonde temperature records and a clear cause – effect reasoning.

 

[pattylou]

The third one, obviously, is the general surface warming as experienced in the last decades. This has it’s own fields of problems like accuracy, (under) estimation of urban heat island effect, conflicting satellite- and balloon radio-sonde temperature records and a clear cause – effect reasoning.

And changes in bloom time and migration routes through North America (and presumably elsewhere) in recent decades.

Thermometers may have problems, but biological systems are pretty reliable.

 

[Andre]

Posting http://w3g.gkss.de/staff/storch/ vision on the hockeystick debate, as he presented on a conference in Boulder.

big file: http://w3g.gkss.de/staff/storch/PPT/paleo/050708.ncar.ppt

• Science no longer curiosity-driven but potentially of great importance for policy definition and social practice.
• High stakes,
high uncertainty.
• Other motives than quest for “truth”.
• … is definitely in a post-normal stage.
• It is heavily politicized.
• The distinction between activists and scientists is blurred.
• The community is split between a large majority of “pro’s” and a small minority of “con’s”.
• The “con’s” are EVIL.
• … is it also in a post-sensible phase?
• Dennis Bray defines post-sensible science as follows; “when moral entrepreneurship begins to infuse the objectivity of scientific thought. This is not limited to any particular perspective but rather to the process of dissemination of scientific information excessively shaped by any moral persuasion.”

• Spiral of ongoing practice of slight exaggeration results in the formation of significant misinformation in the public realm.
• Scientists are part of the public realm, and experts only in a rather narrow field.

Examples of overselling
premature claims

• The hockey stick
• The link of disaster damages and ongoing climate change.
• The claim of universal agreement to the IPCC assessment among climate scientists (the Oreskes case)

Scientific debate constrained by …

• concern for the “evil” “skeptics”, and
• concern for the “good” process of “Kyoto”.
• Thus, the set of scientific knowledge claims enshrined in the IPCC reports must not be doubted.
• Any failure of a key statement of the IPCC assessment reports is made to represent a failure of the entire concept of anthropogenic climate change.
• Any statement, which may be used by the skeptics, is fended off.

Socio-politically constrained scientific discourse

• The historical lesson of the emergence of new, with the contemporary scientific paradigm hardly consistent evidence, is not acknowledged in favor a socio-political correctness.
• Science is downgraded to a repair-shop of contemporary knowledge claims.
• Under the veil of socio-political benevolence, a variety of subjective self-centered agendas are pursued, and deviating, scientifically possible valid approaches are fended off.
• This practice is unsustainable and damages the social institution “science”.

Conclusion

• Science is a social process.
• Long-term acceptance of explanations (theories) is mostly based on evidence and logic, but on short time scales, social arguments and pre-scientific contexts are also important.
• We need to confront claims-making with the same vigor, independently if the claims serve skeptic’s or Kyoto-agendas.
• Break the power of “alarmists” disguised as scientists.
• Engage “skeptics” in a constructive dialogue.

Just for the fun of it ….

… who are the beneficiaries when the perception of anthropogenic, catastrophic climate change prevails?

• climate scientists, who are rewarded with attention, public recognition, careers and funding.
• insurance companies, who find their clients more willing to proactively pay for perceived enhanced risks.
• green political movements, who use the threat of severe man-made climatic interruptions as most useful argument to push other environmental agendas as well.

 

[CobblyWorlds]

Hi again Andre,

The recent warming is unusual for the past 1 or 2 millenia. From the depths of the last Ice Age 20k years ago 1/5 of the warming to current temperatures has occurred in the last 100 years. i.e. 20% of the warming in 0.5% of the time. That is a remarkable and troubling fact. And there are no factors to account for this anomaly.

http://www.realclimate.org/dummies.pdf is an interesting and fair attempt to explain the issues between MBH and MM. To quote from point 8 in this doc. “If you use the MM05 convention and include all the significant PCs, you get the same answer. If you don’t use any PCA at all, you get the same answer. If you use a completely different methodology (i.e. Rutherford et al, 2005), you get basically the same answer. Only if you remove significant portions of the data do you get a different (and worse) answer.”. And their final point “As of now, all of the ’Hockey Team’ reconstructions (shown left) agree that the late 20th century is anomalous in the context of last millennium, and possibly the last two millennia.”

The authors Scmidt and Amman are saying that this is the case inclusive of MM05. Thus MM's data does not show that the current warming is typical of the last 1 to 2 millenia.

 

[Andre]

The recent warming is unusual for the past 1 or 2 millenia. From the depths of the last Ice Age 20k years ago 1/5 of the warming to current temperatures has occurred in the last 100 years. i.e. 20% of the warming in 0.5% of the time. That is a remarkable and troubling fact. And there are no factors to account for this anomaly.

One set of goal poles please. One factor is the last 2 millenia, the other factor is pertaining the last 20 millenia. So what are we talking about? How about the last 1000 millenia, with apparently the same general type of (glacial) cycles. Have we solved that yet? And what do we think about the apparent warming 14,800 cal years BP and 11,670 years BP. 10 degrees within a decade?

If you use a completely different methodology (i.e. Rutherford et al, 2005), you get basically the same answer.

If I use Von Storch 2004 or Moberg 2005 I get a completely different answer.

edit
hmm ...

seeing that Rutherford et al 2005 is Rutherford, Mann, Hughes, Bradley et al, I think I'm not surprised that the results are basically the same. Furthermore I wonder why RealClimate only talks MBH98 avoiding to address the pre 1400AD era (MBH99), which is where M&M found the most problems. Finally "Dummies guide ..." may be a too accurate description

 

[CobblyWorlds]

I'll leave the points regarding MBH and MM for you to take up with the authors of that paper, I think that aside from the pdf version there is also a blog type entry with the facility to post responses, in any case they have had recent discussions on the 'hockey stick'.

One set of goals? What I am saying is that the current warming has not been accounted for by anyone, except those behind the theory of warming due to CO2. Thus the factors behind glaciation(M cycles) and the LIA(Solar radiation reduction) are not present now. Yet we have had a warming in excess of 0.6 deg C, this being in line with what I state.

Climate is variable, no-one with any relevant knowledge finds that a surprise. And I am not here to discuss the vaguaries of paleo-climate I'd rather leave that to those with expertise in that field.

What is this "10 degrees within a decade?" that you allude to? And is it regional or global. If global it seems highly doubtful (unless some aeons ago) if regional - no surprise.

 

[Andre]

What I am saying is that the current warming has not been accounted for by anyone, except those behind the theory of warming due to CO2. Thus the factors behind glaciation(M cycles) and the LIA(Solar radiation reduction) are not present now. Yet we have had a warming in excess of 0.6 deg C, this being in line with what I state.

How about this warming:

http://www.ingentaconnect.com/content/ap/qr/2000/00000053/00000003/art02123 Holocene Treeline History and Climate Change Across Northern Eurasia Quaternary Research 53, 302–311 (2000)
doi:10.1006/qres.1999.2123

Radiocarbon-dated macrofossils are used to document Holocene treeline history across northern Russia (including Siberia). Boreal forest development in this region commenced by 10,000 yr B.P. Over most of Russia, forest advanced to or near the current arctic coastline between 9000 and 7000 yr B.P. and retreated to its present position by between 4000 and 3000 yr B.P. Forest establishment and retreat was roughly synchronous across most of northern Russia. Treeline advance on the Kola Peninsula, however, appears to have occurred later than in other regions. During the period of maximum forest extension, the mean July temperatures along the northern coastline of Russia may have been 2.5° to 7.0°C warmer than modern.

Somewhat different than the possible 0,6 degrees, no? And without any significant carbon dioxide level changes.

 

[Andre]

What is this "10 degrees within a decade?" that you allude to?

That was the horror scenario that started the global warming hype, concerning the discovery of the isotope spikes around the Younger Dryas, recently even increased in magnitude:

Alexi M. Grachev, and Jeffrey P. Severinghaus A revised +10±4 °C magnitude of the abrupt change in Greenland temperature at the Younger Dryas termination using published GISP2 gas isotope data and air thermal diffusion constants, Quaternary Science Reviews Volume 24, Issues 5-6 , March 2005, Pages 513-519

Abstract
We revisit the portion of (Nature 391 (1998) 141) devoted to the abrupt temperature increase reconstruction at the Younger Dryas/Preboreal transition. The original estimate of +5 to +10 °C abrupt warming is revised to +10±4 °C. The gas isotope data from the original work were employed, combined with recently measured precise air thermal diffusion constants (Geochim. Cosmochim. Acta 67 (2003a) 345; J. Phys. Chem. 23A (2003b) 4636). The new constants allow a robust interpretation of the gas isotope signal in terms of temperature change. This was not possible at the time of the original work, when no air constants were available. Three quasi-independent approaches employed in this work all give the same result of a +10 °C warming in several decades or less. The new result provides a firm target for climate models that attempt to predict future climates.

The question is, if this can be backed by other types of proxy evidence not equal to isotopes.

 

[CobblyWorlds]

Sorry I didn't get back more promptly Andre,

Thanks for the info re the 10 degrees, I agree that further proxy data would be useful. At least we're not facing that kind of warming now. If these figures are global, not local then such a rise would be stunning, in the case of impacts on human society, literally so!

However I stand by what I've said, I can't see any mechanism that accounts for the tropo. warming and upper strato cooling. And with only a 1/3 increase (from pre-industrial) of a minor GHG, CO2, that is troubling. What's happened in the past is useful, but at present, with the panoply of technology we have, there seems no alternative to the CO2 warming theory.

 

[Andre]

I can't see any mechanism that accounts for the tropo. warming and upper strato cooling.

The radiosondes which are the only to measure the tropo pause temperatures directly do have a different story to tell. I believe that Fu still has not succeeded in cranking up the satellite trend readings that agree with the radio-sondes. But all this is futile having only a few decades of data, way short of distinguishing chaotic cycles from one way trends

What's happened in the past is useful, but at present, with the panoply of technology we have, there seems no alternative to the CO2 warming theory.

Make that “understanding the past is essential for seeing what is happening”. Why not check the adjacent extinction thread for alternatives derived from another understanding of the past?

 

[CobblyWorlds]

The radiosondes do nonetheless show a warming trend...

Understanding the past is of interest and is needed to ensure we're not missing anything. BUT I've yet to hear a coherent alternate explanation for the observed warming. Most of these are just plain wrong and poorly thought out.

 

[Andre]

The radiosondes do nonetheless show a warming trend...

http://home.wanadoo.nl/bijkerk/ghcn-sat-son-trends.jpg

Darn You are right indeed A full 0.04 degrees C per century.

source

I believe that the infallible CO2 global warming theory is still http://www.geology.yale.edu/~scs46/radproj/ with that rebellious radiosonde dataset. After all, it’s the only tool that can measure temperatures directly and unbiased.

So let's go over the greenhouse idea once more.

Facts & physics: The sunlight that hits the Earth surface is absorbed by the surface, heating it. CO2 is not interfering with this. The surface heating causes reradiating of heat waves (Infra red) and some of this is absorbed by the CO2 molecules in the air, warming the air.

Hypothesis: So with more CO2 in the lower atmosphere air, (troposphere) gets warmer and since this is the first effect this trend should be the strongest. The warmer troposphere is keeping the Earth warmer but this is secondary and hence this should be the weaker trend. Due to this resistance of IR radiation the higher atmosphere, or stratosphere cools.

Testing the hypothesis: Earth warming is strongest, troposphere warming by satellite observation is much less, radiosonde observation corrolates well with the satelllites but shows no significant trend. Not in the graph is strratosphere but it cools indeed as the hypothesis assumed. However The remainder is not, instead, we see the opposite. So that's two counts where the hypothesis fails against one to be correct.

The scientific method would now require atleast an adjustment of the hypothesis that CO2 is causing global warming. But why isn't that happening? Of course we do see attempts to crank up the troposphere satellite trends (Fu et al) to force the hypothesis to be right, but unfortunately, those radiosonde data are spoiling that.

 

[Andre]

OK Back on topic. The hockeystick saga only just has begun.

Mann et al have answered the questions of Barton:

http://www.realclimate.org/index.php?p=172

I wonder why Mann always includes his version of the CV's of McIntyre & McIttrick in whatever he writes. Anyway.

A lot of comments here ( note especially the R2 calculation problems) and here.
which makes you wonder if things are not a whole lot worse than http://www.technologyreview.com/forums/forum.asp?forumid=899&iPage=9 :

...It was unfortunate that many scientists endorsed the hockey stick before it could be subjected to the tedious review of time. Ironically, it appears that these scientists skipped the vetting precisely because the results were so important.

Let me be clear. My own reading of the literature and study of paleoclimate suggests strongly that carbon dioxide from burning of fossil fuels will prove to be the greatest pollutant of human history. It is likely to have severe and detrimental effects on global climate. I would love to believe that the results of Mann et al. are correct, and that the last few years have been the warmest in a millennium.

Love to believe? My own words make me shudder. They trigger my scientist's instinct for caution. When a conclusion is attractive, I am tempted to lower my standards, to do shoddy work. But that is not the way to truth. When the conclusions are attractive, we must be extra cautious.

The public debate does not make that easy. Political journalists have jumped in, with discussion not only of the science, but of the political backgrounds of the scientists and their potential biases from funding sources. Scientists themselves are also at fault. Some are finding fame and glory, and even a sense that they are important. (That's remarkably rare in science.) We drift into ad hominem counterattacks. Criticize the hockey stick and some colleagues seem to think you have a political agenda--I've discovered this myself. Accept the hockey stick, and others accuse you of uncritical thought...

I do wonder however, why the hockeystick-being-true is so incredibly attractive.

The soap continues...

 

[Andre]

News on the Hockeystick front:

Marcel Crok, the author of the article http://www.uoguelph.ca/~rmckitri/research/Climate_L.pdf has won a prestigious prize for that. http://www.natutech.nl/nieuwsDetail.lasso?ID=2620&-session=NTses:2866CA03D84BC6998390CDDA63F654C0/ of the Amsterdam Free University. He explains in a clear and well written way the flaws that McIntyre and McIttrick had found in the MBH hockeystick.

Is this a sign that the hype is over the hill?

Well done, Marcel, way to go!

 

[deckart]

I've just read the paper. What is it about human behavior that causes us to jump to sensationalism over reason so quickly? Thanks for the update, Andre.

 

[Andre]

My pleasure, decKart.

What is it about human behavior that causes us to jump to sensationalism over reason so quickly

I have attempted to ramble an answer for your question here:

https://www.physicsforums.com/showthread.php?t=54723