The Instigator
Thaumaturgy
Con (against)
Losing
10 Points
The Contender
RoyLatham
Pro (for)
Winning
14 Points

The Hockey Stick is Bad Science

Do you like this debate?NoYes+6
Add this debate to Google Add this debate to Delicious Add this debate to FaceBook Add this debate to Digg  
Post Voting Period
The voting period for this debate has ended.
after 6 votes the winner is...
RoyLatham
Voting Style: Open Point System: 7 Point
Started: 5/10/2012 Category: Science
Updated: 5 years ago Status: Post Voting Period
Viewed: 6,180 times Debate No: 23535
Debate Rounds (4)
Comments (87)
Votes (6)

 

Thaumaturgy

Con

As a follow on to a recent comment Roy made in the Science forum on the topic of possible upcoming debates that a "narrow" "global warming" debate may be in order. He specifically posed the possibility of a debate on the Hockey Stick of Mann et al. (1998 et seq.)

I propose to argue against the proposition that "The Hockey Stick is Bad Science". My position will be that the so called Hockey Stick graph as originally developed in 1998 by Mann, Bradly and Hughes, further expanded by Jones et al in 1998 (see references below) and Mann et al in 1999 is "good science" in that it fufills the following criteria:

1. It represents a legitimate analysis of temperature and paleotemperature data using appropriate statistical tools and proxies

2. It was honestly undertaken

3. Relying on the information available it shows significant warming in the recent past that can be reasonably assumed to be in support of the anthropogenic climate change hypothesis

I will also ask that other studies be allowed in evidence (in that science always benefits from repeated analyses from different viewpoints). I will ask that standard climatological, physical, chemical, paleoenvironmental and statistical terminology and techniques be adhered to.

The first round will be for Acceptance

Second-Third Round Presentations and Rebuttals

Fourth Round Summary.


Starting Resources:
MBH98: Mann, M. E.; Bradley, R. S.; Hughes, M. K. (1998). Nature 392 (6678): 779–787

MBH99: Mann, M.E.; Bradley, R.S.: Hughes M.K. (1999)
Northern Hemisphere Temperatures During the Past Millennium: Inferences, Uncertainties, and Limitations, GEOPHYSICAL RESEARCH LETTERS, VOL. 26, NO. 6, PP. 759-762

Jones, P.D.; Briffa, K.R.; Barnett, T.P.; Tett, S.F.B. (1998). "High-resolution palaeoclimatic records for the last millennium: interpretation, integration and comparison with General Circulation Model control-run temperatures". The Holocene 8 (4): 455–471
RoyLatham

Pro

I accept the challenge.

For those unfamiliar with a subject now ancient history, the Global Warming Hockey Stick is graph of global temperature versus time. It's named for the shape of a recumbant hockey stick. Temperatures are nearly flat for a thousand years, then they rise exponentitally in the last two decades of the Twentieth Century. The exponential rise in recent years was cited as proof of human-caused global warming. The rapid rise was cited as a good reason to believe that there wuld be a very sharp temperature rise after the 2000, and that therefore mmediate action was required to stop fu CO2.

I won't contest that the derivation of the Hockey Stick was honestly undertaken. The errors were in selcting invalid proxies, not estalishing that the proxies had a physical tie to what wasbeing measured, and using the poxies outside of the range for which they were validated, I am not arguing any of these things in this round, but since con initiated the debate as Con, I'm giving him a head's up as what I will argue so he can make his case for validity.

About everyone agrees there has been global waror the past 150 years. What's contested is whether it is entirely anthropogenic and has an exponential character as he Hockey Stick purported to show. The Hockey Stick also made The Little Ice Age and the Medieval Warm Perid disappear. I will argue that they existed.
Debate Round No. 1
Thaumaturgy

Con


The hockey stick which started out in the earlier cited MBH98 citation (see Round 1) was predicated on the idea of extending the surface temperature record back beyond the current instrumental record which, at best is only about 150 years. The use of “proxy” data is what MBH and others over the past years have used to achieve this task.


Proxies are merely items that contain some aspect that relates to some other physical attribute. Proxies are quite commonly used in all manner of paleoenvironmental and geochemical studies and are in no way controversial.


The proxies in question for the hockeystick were chosen as temperature or climate proxies. Climate proxies include things like tree rings, corals, ice cores, lake sediment cores, speleothems, etc. Since the original MBH98 citation there have been numerous additional studies each of which shows the now famous “hockey stick” pattern as Roy described. A 2008 study by Mann et al. expanded the number of proxies to about 9 different types of temperature proxy [1].


Since the use of proxies is extremely common in paleoenvironmental analyses we cannot fault the reliance on proxies for the development of the hockey stick. If the choice of proxy is problematic then we must know exactly why this is the case. If there is objection to tree ring proxies then why do speleothems (cave formations) [2] show a hockey stick shape to the data? Why do glacier measurements show a hockey stick shape?[3] Why do borehole analyses [4] show a hockey stick shape? Why would coral or ice core paleoclimate proxies show a hockeystick shape? It is quite difficult to imagine how so many disparate techniques can show the same general trends and yet one or two are “controversial”.


As for Pro’s contentions: “What's contested is whether it is entirely anthropogenic and has an exponential character as he Hockey Stick purported to show.” This is a mischaracterization. No serious climate scientist thinks climate change is solely due to anthropogenic factors as even a cursory examination of the IPCC report will show [5]. Natural forcings are explicitly considered and factored into the calculations. Many of these are actually positive forcings as well.


The second contention: “ The Hockey Stick also made The Little Ice Age and the Medieval Warm Perid disappear. ..” Is also problematic. The MWP and LIA are known to be real and if they show up as less than Pro would prefer that is only due to how the data lined up. (The MWP is still under debate as to it’s geographic extent.)


If Pro wishes to bring this point into the debate it will have to be in the context of the original debate. He will have to show that the relative temperature change due to the MWP compared to modern temperature increase is due to “bad science”. As such Pro bears the burden of showing the error in the science .


SOURCES:



  1. Mann, M.E., Zhang, Z., Hughes, M.K., Bradley, R.S., Miller, S.K.,Rutherford, S., Ni, F., Proxy-based reconstructions of hemispheric and global surface temperature variations over the past two millennia , Proceedings of the National Academy of Sciences Vol. 105, No. 36, pp. 13252-13257, September 9, 2008.

  2. Smith, C.L, Baker, A., Fairchild, I.J., Frisia, S., Barsato, A., 2006, Reconstructing hemispheric-scale climates from multiple stalagmite records. International Journal of Climatology Vol. 26, Issue 10, pp. 1417 – 1424

  3. Oerlemans, J., 2005, Extracting a Climate Signal from 169 Glacier Records, Science 29 April 2005: Vol. 308 no. 5722 pp. 675-677

  4. Huang, S., Pollack H., Shen, P-O, 2000, Temperature trends over the past five centuries reconstructed from borehole temperatures, Nature, v 403 p 756

  5. http://www.ipcc.ch...

RoyLatham

Pro

Climate Reconstruction Using Proxies

Con correctly states that proxies are widely used in the historical reconstruction of temperatures. That is because there have only been reliable widespread direct temperature measurements for about a century. Scientist would like to know what temperatures were like before that. There are quite a number of measurements that can be used to deduce temperatures. con mentioned a few, but there are more. Some are better than others. Tree rings depend upon rainfall as well as temperature, and only reflect climate during the growing season. Trees of different species or at different altitudes or in different local climates will produce different indications of climates. Some species grow more rapidly due to the carbon dioxide rise in the 20th century.

Local variations affect virtually every type of proxy. Scientists must use statistical methods to attempt to derive correct temperature reconstructions. By 2003, at least 350 historical temperature reconstructions had been published, with contributions from around the world. If all the data are combined, the picture of climate for the past thousand years is not a hockey stick. Con asks why there are four of the 350 that show hockey sticks. With 350 to choose from, finding four for almost any shape is not be surprising, given the variability. However, it seems that Prof. Mann and his colleagues shared tips on processing techniques, and the methods they derived works to make a hockey stick result out of any large data set.

I don't believe there is any deliberate attempt to falsify data and I'm not alleging any malfeasance. The group seized upon a bad method and believes to this day it is correct. This is not shocking. Climate scientists are not experts in statistical methods, so it took experts in mathematical statistics to unravel the errors.

The graphs below are scaled versions of those in [1. http://www.john-daly.com... ] The IPCC report of 1990 (A) had an entirely different graph of climate history. That graph showed a Medieval Warm Period (MWP), warmer than the present and lasting to about 1300, followed by the Little Ice Age, a period much colder than the present lasting through the early 1800's. Both disappeared in the hockey stick. (B) [1] shows a number of climate reconstructions confirming (A) and disconfirming (B).


conventional temperature reconstruction (A) Mann's Hockey Stick reconstruction (B) of world climate

Mann's Errors

Why did major climate variations disappear in the hockey stick? Scientists, led by Ross McKitrick, a professor at the University of Guelph in Canada, spent enormous effort trying to reconstruct Mann's work to find out. Mann refused to supply his data or the computer program that he used to process the data. Under intense pressure, enough of the data was revealed and enough information about the algorithms was revealed to allow reconstructing and analyzing the methodology. The actual software had never been released.

The details of the analysis are provided in full in a thirty page article by scientist Ross McKitrick, [2] "The Mann et al Northern Hemisphere 'Hockey Stick': A Tale of Due Diligence." published in the book "Shattered Consensus" edited by Patrick Michaels. A good summary by a scientist who believes in human-caused global warming is from the MIT magazine Technology Review: [3. http://www.technologyreview.com...]

The basic errors in the hockey stick derivation are:

1. Mann used an algorithm that normalized past data based upon the data of the last 78 years. This algorithm was tested by putting noise into the algorithm. Noise is fake data that just bounces around with no trends. When processed through the Mann algorithm, a hockey stick is produced. It makes hockey sticks out of nothing.

2. Mann used a method called "component analysis" as part of his method. When the raw climate data is put into a standard off-the-shelf computer program that does component analysis, the MWP and Little Ice Age reappear as they were in the 1990 IPCC report.

3. A variety of different types of data were used as inputs to Mann's analysis. The data are various proxies for temperature, like tree ring growth. Most of the data does not show a hockey stick, but one data set from the rings of trees growing at high altitudes did show a hockey stick. Mann not only included it, but weighted it 380 times more highly than other data.

"Almost all of the ... series selected for overweighting [by Mann] were of a single type and from a single researcher, Donald Graybill. The series were high-altitude bristlecone pine tree-ring chronologies, many of which had been studied by Graybill and Sherwood Idso as possible examples of CO2 fertilization of tree growth, following a similar study by Lamarche et al. on Sheep Mountain. The sites were selected for "cambial dieback," that is, the bark had died around the circumference of the tree. ... They related that the anomalous twentieth century growth was unrelated to the temperature from nearby weather stations." McKitrick in Michaels, [2] p 41

Mann didn't hand-select the odd data to be overweighted, his computer processing did it automatically. The method selected matches to recent instrumental data and weighted them as the best proxies. Since the match was a matter of chance, earlier data from those proxies was mostly noise. Later examination of the chosen proxies showed they didn't track the next decade at all.

4. There were errors in the method of filling in missing data.

Expert Evaluation

Mann said he didn't have the time to reveal his data or computer programs, and that no matter what critics did to reconstruct his work, Mann claimed they were not doing it right. Pressure mounted, and ultimately the National Science Foundation was asked to investigate the matter. They came back with an obfuscated report that seemed to confirm the criticisms, but at the same time didn't say the hockey stick was wrong.

The matter was finally referred by Congress to a panel of statistical experts experienced in the processing of climate data. The panel featured Edward Wegman. Wegman is a statistics professor at George Mason University, and past chair of the National Research Council's Committee on Applied and Theoretical Statistics. He holds a Ph.D. in mathematical statistics and is a Fellow of the American Statistical Association. He was selected to provide the highest level of expertise on the statistical methods employed. Wegman and the panel determined unambiguously that the critics were correct, and that the hockey stick was invalid.

Harvard Smithsonian Metastudy

In 2003, the Harvard Smithsonian Center for Astrophysics reviewed 350 published reconstructions and concluded:

"... the 20th century is neither the warmest century nor the century with the most extreme weather of the past 1000 years. The review also confirmed that the Medieval Warm Period of 800 to 1300 A.D. and the Little Ice Age of 1300 to 1900 A.D. were worldwide phenomena not limited to the European and North American" continents. [4. http://www.cfa.harvard.edu...]

Aside from the data reconstructions, books have been published documenting the exceptional nature of the MWP [5. http://www.amazon.com...] and the LIA [6. http://www.amazon.com...]. the MWP had Greenland named for its greenery and grapes growing in northern Scotland. The LIA produced painting of ice skaters on the canals of Holland and a yearly festival on the ice of the Thames.

Why the Hockey Stick is Bad Science

The hockey stick was derived using incorrect procedures. It wrongly claimed temperatures were soaring exponentially, and because it was allegedly unprecedented, we should expect that to continue. So have they continued to soar exponentially since the late 90s? No, actually the trend was slightly downward after 1995. [7. http://www.factsandarts.com...]
Debate Round No. 2
Thaumaturgy

Con

The four examples I chose were randomly chosen as disparate techniques which share almost nothing in common but are all published reconstructions showing hockey stick shape.


Statistics Critiques

Pro raises an interesting point about the statistical basis used for the analyses of MBH. Pro incorrectly refers to it as “component analysis”. It is actually PCA (Principal Component Analysis) and yes it is a somewhat advanced technique but Pro’s assessment that climatologists are not statistics experts and failed for this reason is undercut almost immediate when his first reference is Ross McKitrick, an economist. In point of fact many scientists (myself included) have to have some experience with statistical analysis of data as part of our tool box. But no one argues that more statistical expertise (on both sides) would be of value

The critiques cited by Pro attributed to Ross McKitrick in the book “Shattered Concensus” (not a peer reviewed scientific publication) are not available to me, but I am very much aware of McKitrick and analyses of Mann et al’s data as described in the article he co-authored with Stephen McIntyre [1], and, in many ways, it appears to be flawed statistically.

First of all the centering convention chosen does not significantly impact important factors of the PCA analysis in this case. The MBH98 analysis is very insensitive to the centering convention whether it is that baseline chosen by McKitrick and McIntyre (M&M) or MBH. Apparently the argument against the centering convention by M&M is predicated on their failure to use the proper number of PC’s base on “selection rules” (Priesendorfers Rule N). With the M&M centering they should have retained 5 principal components whereas with MBH 2 should be retained. With MBH the hockey stick shape shows up in the first PC whereas in the M&M’s constructions it shows up in the 4th PC. It’s still there. BUT McKitrick and McIntyre erroneously truncated THEIR PC’s down to 2. So yes, when you misapply the procedure you can, if needed, eliminate the hockeystick shape.

In addition M&M incorrectly eliminated several proxy data sets resulting in spurious warming in the 15th century [2]

Pro then also notes the large reliance on a small set of tree data from Graybill and Idso. MBH’s reliance on a technique of PCA called an “eigenvector-based CFR Technique” takes into account the regional climatic effects that Graybill and Idso were originally focusing on and, according to a study by Wahl (2007) [3] this data carries “important climate information at the level of eigenvector patterns in global surface temperatures. These results are valid notwithstanding issues concerning these proxies’ empirical relationship to local/regional surface temperatures after 1850…” (so the implication that this data is somehow improper is ameliorated to some extent). Further “…these proxies do not generate spurious increases in calibration fit that thereby downweight the value of other (presumably more locally climate-correlated) proxy series.” Wahl even finds that eliminating the Bristlecone/Foxtail pine data set still results in a single bladed hockey stick shape! Finally Wahl’s analysis do NOT support the upward “correction” of McIntyre and McKitrick in the 15th century and “leave unaltered the single-bladed hockey stick conclusion of strongly anomalous late 20th century temperatures. “ Further they conclude that M&M’s reconstruction showing 15th century temperatures higher than those of the mid 20th century “…do not have climatological meaning.”[3]

As for the point about “infilling” errors on the data, this is presumably in reference to the St. Anne (“Gaspe”) data. Removal of this data set may result in a slight upward adjustment of only about 0.05deg) but does not alter the finding of anomalous warming in the late 20th century.

Wahl finally notes:

“Overall, the primary outcome from our results is that the work reported in MM03, MM05a, and MM05b does not provide substantive reason to invalidate the general conclusion of anomalous warmth in the later 20th century derived from the MBH reconstruction method and proxy data framework. We find that this result is neither an artifact of selection of the proxy series nor the result of formation or application of PC summaries in the reconstruction procedure”

The Wegman hearing

It should be noted that during this hearing Wegman was only asked to provide information about the “centering” of the PCA analysis, and strangely not whether it altered the final hockeystick result (!) His finding was that centering made a difference in the first principal component. Which was already acquiesced to. The key is that McKitrick and McIntyre appear to have incorrectly eliminated the PC that did show the hockey stick, whereas MBH did not! So Wegman is correct in his point, but that does not mean that McKitrick and McIntyre’s point is correct.

Interestingly enough, if you throw out all the fancy PCA statistics altogether YOU STILL GET A HOCKEYSTICK! Rutherford et al (2005)[2] did this very thing and still got a hockeystick!

Harvard-Smithsonian Meta Study of Soon et al. (2003)

This been largely discredited in a number of journals such as EOS and Science. In fact the editor of the journal in which Soon and Baliunus published this went so far as to publish the following statement: “While these statements may be true, the critics point out that they cannot be concluded convincingly from the evidence provided in the paper. CR should have requested appropriate revisions of the manuscript prior to publication.” The Soon et al article even lead to one of the lead editors of CR to resign in protest. A detailed rebuttal to Soon et al. as published in EOS can be found in reference [4] below.


There is still much debate within the climate community about the nature of the Medieval Warm Period. The primary problem with this is that the MWP doesn’t seem to show “synchronous” warming on a hemispherical scale. It appears to show localized warming in different areas at different times. This is why this is still not a settled issue. And certainly not to the level of decreeing it somehow more extreme than the current warming which so far has not been possible to explain without explicit reliance on anthropogenic factors along with natural factors.

It is clearly possible to disagree on statistical and analytical methodology as we all know. The Hockey Stick was done using appropriate statistical methods (and indeed the critics appear to have used inappropriate methods) but even if there is a difference in opinion on the choices of analytical methods does not change the quality of the science. The hockey stick is robust. And, indeed, seen in numerous reconstructions by different groups using different methods with and without PCA and using different proxies.

Good science is reproducible science and this is reproducible science.

SOURCES

[1] McIntyre, S., McKitrick, R., 2003, Corrections to the Mann et. al. (1998) Proxy Data Base and Northern Hemispheric Average Temperature Series, Energy and Environment, v14, pp751-771

[2]Rutherford, S., Mann, M.E., Osborn, T.J., Bradley, R.S., Briffa, K.R., Hughes, M.K., Jones, P.D., Proxy-based Northern Hemisphere Surface Temperature Reconstructions: Sensitivity to Method, Predictor Network, Target Season, and Target Domain, 2005, J. Climate, V18

[3] Wahl,E., Ammann, C.M, 2007, Robustness of the Mann, Bradley, Hughes reconstruction of Northern Hemisphere surface temperatures: Examination of criticism based on the nature and processing of proxy climate evidence, Climate Change, v85 pp33-69

[4] http://holocene.meteo.psu.edu...

RoyLatham

Pro

Bad Science

If the hockey stick is good science, then ice skating on Dutch canals and ice festivals on the Thames during the Little Ice Age must have been faked. The Hockey stick shows them to be impossible. Con acknowledged that natural phenomena play a role in climate change. However, the Hockey stick shows that nothing whatsoever has happened in climate for a thousand years, until humans caused global warming in the 20th century.

It was bad science for Mann et al to conceal how the hockey stick was derived, claiming it was proprietary. That defeats peer review.

The hockey stick analysis ended on what is now widely recognized as a temperature spike caused by an unusually strong El Nino event in the 1990s, which had nothing to do with CO2. Does the good science of the Hockey Stick cancel the obvious El Nino transient. Con points to Mann and his colleagues being able to continue to construct hockey stick graphs. Every confirming paper con sites included Mann as a coauthor. No doubt about it, they know how to make hockey sticks. For a small fee, I'll make a hockey stick out of climate data as well. The method is to write software that heavily over-weights anything that looks like a hockey stick and underweight everything hat doesn't.

Statistical Analysis is an expert specialty

Con attacks McKitrick as being a professor in the Economics Department of his university, the University of Guelph in Canada. He specializes in environmental economics. Economics is probably closer to the field of statistics than climate science, but no matter, the analysis stands on its own. McKitrick was also a consulting expert in statistical analysis of mineral exploration data for validity. People trying to sell mining claims would use every statistical technique available to attempt to establish the value of a claim from limited assay data. McKitrick sorted valid claims from every bogus use of statistics in the book,.

Statistical expertise is not tied to a particular discipline. It is certainly possible for Mann to have been an expert in statistics; it just turns out that he was not. A PhD in climate science may not require s much as a single course in statistics. As part of the Senate hearings, the scientists who provided peer review for the original Mann paper all acknowledged they lacked the expertise in statistics needed to review it properly. Wegman showed that Mann confined his work to a small group o like-mined associates and never subjected it to mainstream statistical expertise. [8. http://www.uoguelph.ca...]


Con suggests that Wegman only objected to one minor point that had no effect on the conclusion. Here are some excerpts from the Senate expert panel's report:

“In general, we found MBH98 and MBH99 to be somewhat obscure and incomplete and the criticisms of MM03/05a/05b to be valid and compelling. … It is not clear that Dr. Mann and his associates even realized that their methodology was faulty at the time of writing the MBH paper. The net effect of the decentering is to preferentially choose the so-called hockey stick shapes. … [paraphrasing here:] MBH method creates a PC1 statistic dominated by bristlecone and foxtail pine tree ring series (closely related species). However there is evidence in the literature, that the use of the bristlecone pine series as a temperature proxy may not be valid (suppressing "warm period" in the hockey stick handle); and that bristlecones do exhibit CO2-fertilized growth over the last 150 years (enhancing warming in the hockey stick blade). “ [9. http://en.wikipedia.org...]


Wegman separately stated, “We explicitly looked at the first principle component of the North American Tree Ring series and demonstrated that the hockey stick shows up when the data are decentered, but not when properly centered.” [8, http://www.uoguelph.ca...] Wegman explicily stated that the hockey stick was "bad science."

McKitrick's book article was not peer reviewed, but all the material was also published in Geophysical Research Letters in 2005, and was nominated as a journal highlight by the American Geophysical Union.

The Mann Team

Wegman showed that Mann confined his work to a small group o like-mined associates and never subjected it to mainstream statistical expertise. [8.] They review each others papers, defend the hockey stick, generate new hockey sticks, and work to prevent critics from being published. The group is defined primarily by observing the small universe of paper reviewers that comprise the group, but they also contribute to Mann's blog, work together on committees, and sometimes e-mail is published.


In the Climategate scandal, e-mail among global warming advocates revealed that they worked to prevent publication of any papers contrary to their theory. [9. http://reason.com... ] That has undermined confidence in the peer review process. Mann and his associates have continued to rationalize their methods, but they are amateurs at statistical analysis compared to McKitrick and rank amateurs compared to Wegman.

Additional hockey sticks are generated by the Team. These pretend to be independent, but they actually share the methodology of selecting and over-weighting data that looks like a hockey stick, and they share faulty tree ring data that produces the hockey sticks. [10. http://climateaudit.files.wordpress.com... ] The trees exhibiting the hockey stick were resampled ten years later, and the new grown did not show a continuation of the hockey stick and, even more surprisingly, Simple taken as little as six inches away on the twisted trees from those selected for hockey stick inclusion showed a different pattern. [10]


The Mann rationalizations they are weasel-worded with claims that the MWP was not proved to be warmer than the present, as if that were the key issue at stake. No, the key issue was that the Hockey Stick incorrectly wiped out all natural variations in climate for the past thousand years, a claim disproved by paintings of the Dutch ice skating, never mind McKitrick. As far as I know, everyone in paleoclimatology agrees that the Holocene Optimum, about 4000 to 8000 years age, was warmer than the present. So whether the MWP was few tenths of degree warmer or cooler than the present isn't significant.. Another weasel-wording is to produce curves that are sort of U-shaped and say they confirm the Hockey Stick.

The MWP

Con claims the Harvard study verifying the existed other MWP has been discredited. Only in the minds of the Mann Team. Many others disagree:

The conclusion of Soon & Baliunas? That the vast majority of published, peer-reviewed papers on the MWP conclude that it was both geographically widespread (not, as Warmists and their amen corner in Wikipedia like to pretend, a little local anomaly confined to Northern Europe) and significantly warmer than now.

This irritates Michael Mann and his Hockey Team no end, for it contradicts their view that late 20th century warming is both unprecedented and catastrophic. So how do they respond? Do they counter it with new, learned papers demonstrating in closely illustrated detail just where Soon & Baliunas have got it wrong?

Of course they don't!

Instead, what they do is gang up to shoot the messenger. They conspire to have Climate Research closed down; to have Chris de Freitas sacked; then, they write to the head of his university in Auckland to see if they can't get de Freitas deprived of his living too. Nice!

http://blogs.telegraph.co.uk...

We are not dead from the exponential rise in temperatures the curve predicted. Instead temperatures have bounced around at about the same level. Bad methods make bad predictions which make bad science.


Debate Round No. 3
Thaumaturgy

Con

I would like to thank Roy for a spirited debate. I will take the first part of this response to rebut his last points and then summarize my contention.

Firstly: there is nothing about the hockeystick that makes cold weather in the Little Ice Age an “impossibility”. It is equally incorrect to say that the hockey stick shows “no climate change” for thousands of years. In my original proposal I explicitly stated that the discussion was about the hockey stick as originally developed and further expanded. As an example of the “change” available in the hockey stick reconstructions throughout its history I provide the following illustration from Mann et al, 2003 [1]



There appears to be quite a bit of change in the climate. The problem Pro has with the hockey stick is that it doesn’t show his preferred issues as “large” as he would like them to be. Unfortunately GOOD science is done without preconceived notions. The data fall where they fall. Unless Roy can point to a significant and obvious error in treatment of the data then the data shows what the data shows.

Now, mysteriously, Pro wishes to bring up some nefarious hidden actions by Mann and associates and intimates that they are setting out to make software that heavily weights certain data, preventing critics from being published and ultimately resorts to the “climategate e-mails” (which have been examined by numerous panels and none so far have found evidence of fraudulent science). This sounds very much like an accusation of dishonesty. Yet in Round 2 Roy explicitly agreed that the hockey stick was likely honestly undertaken. Here is his exact phrasing:

“I won't contest that the derivation of the Hockey Stick was honestly undertaken. The errors were in selcting invalid proxies, not estalishing that the proxies had a physical tie to what was being measured, and using the poxies outside of the range for which they were validated…”

It seems that Pro wishes now to recapture a conceded point here. And since none of these issues are related to Pro’s original I cannot allow this.

Pro fails to substantively discuss the details of the principal component analysis which underlays the primary critique of McKitrick and McIntyre against Mann. I showed how McKitrick and McIntyre failed and how Mann et al explicitly followed standard statistical procedure (whereas McKitrick and McIntyre explicitly FAILED to follow standard procedure). In order for Pro to make a valid critique of this as “bad science” he must show how the proper application of accepted statistical analyses was in error for Mann and how misapplication (incorrect truncation of the number of PC’s) was somehow ‘correct’ for McKitrick and McIntyre.

Wegman’s testimony is very interesting. It would be great if Wegman would take his work to the statistics community via regular publication rather than just testimony before Congress. Perhaps this would open it up to peer review? (Note I am not questioning Dr. Wegman’s statistics at all! Quite the contrary. If I am to believe Roy’s point in the last post if this is a good, legitimate critique it would be best put to the broader statistical community and not just a Congressional Committee). It appears that Wegman spent an inordinate amount of time explaining “social networks” FIRST before launching into a critique of Mann et al.’s actual statistics. But it is also interesting that Wegman took a swipe at Wahl and Amman’s 2006 paper. Interestingly enough if Wegman wished to question the use of real statisticians it appears that Wahl and Amman actually consulted the National Center for Atmospheric Research’s Geophysical Statistics group head.

But again, back on statistics, Wegman appears to have focused on the first PC (Pg 9 of the Testimony) and the impact on centering which was really not controversial to begin with.

Wegman was by no means the only statistician in attendance. Hans Von Storch (coauthor of one of the leading books on statistics in climatology) also testified [2], and his testimony found that decentering had only a minor effect on the final outcome after all the PC’s were added into the reconstruction. Interestingly von Storch himself found things he disagreed with in MBH and found the ensuing canonization of the hockey stick should have been moderated. This is par for the course in any scientific publication. This even happens to “good” science!

I addressed the regional effects of the choice of the Bristlecone and foxtail pine proxies by reference to the eigenvector-based CFR Technique as discussed in Wahl (2007) and how those were factored in. In addition I noted that Wahl removed that data and still found a single-bladed hockey stick shape to the data. This indicates that it is not clearly just “bad” form for MBH to utilize these techniques. There may be disagreements but is not dispositive for “bad science”.

Pro’s repeated reliance on some small circle of Mann’s associates seems somewhat strange since easily more than half of the publications I cited do not include Mann. One is from LDEO, one is from NCAR, one is the IPCC. I feel I have shown a variety of independent sources.

Pro also appears to want to expand the debate to the Holocene Optimum and other points in the earth’s history. Indeed the earth has had very warm periods in it. However, these say nothing about the possibility of anthropogenic warming today. The debate here was limited to the proposition of the hockey stick as "bad science".

I must say that Pro’s continual reliance on non-peer reviewed citations, congressional testimony, Wikipedia and the Telegraph newspaper in critique of science is somewhat of a mystery to me.

SUMMARY

In order for science to bad it must be either:

  1. Undertaken dishonestly
  2. Reliant on such misapplication of standard scientific or analytical techniques as to make it patently obvious to a majority it was flawed
In this debate Pro initially agreed that it was not #1 when he stated he felt it was honestly undertaken. And as to the application of standard scientific or analytical techniques I substantively responded to those points and even noted that the primary critiques of McKitrick and McIntyre relied on inappropriate truncation of the principal components.

In order for science to be “good” it must be:
  1. Honestly undertaken
  2. Rely on standard scientific and analytical techniques (or failing that to provide ample explanation of why different techniques were considered
  3. Show robust findings
  4. Be reproducible

I have shown these things to be true of the hockey stick. We both agreed it was honestly undertaken (even if Roy seemed to attempt to backpedal on this point in the recent round), while some may disagree with the techniques chosen, it is not exclusive to MBH. I further provided evidence of the robustness of the analysis by reference to Wahl and Amman (2007). I provided evidence of the reproducibility of the hockey stick in a number of ways relying not just on alternate proxies, but also without reliance on the PCA technique!

This does not mean the hockey stick is “perfect”. No science ever is. It cannot be. But it is “good” science in that there is little reason to doubt the results since external groups have analyzed the results, found them acceptable, and even were able to reproduce the hockey stick without reliance on the statistical techniques.

Mere disagreement over the outcomes (or rather what some would prefer the outcomes to be) does not equate to science being “bad”.

SOURCES

  1. Mann, M.E., Ammann, C.M., Bradley, R.S., Briffa, K.R., Crowley, T.J., Hughes, M.K., Jones, P.D., Oppenheimer, M., Osborn, T.J., Overpeck, J.T., Rutherford, S., Trenberth, K.E., Wigley, T.M.L., On Past Temperatures and Anomalous Late 20th Century Warmth, Eos, 84, 256-258, 2003
  2. House Hearing, 109th Congress - QUESTIONS SURROUNDING THE 'HOCKEY STICK' TEMPERATURE STUDIES: IMPLICATIONS FOR CLIMATE CHANGE ASSESSMENTS (http://tinyurl.com...)
RoyLatham

Pro

I thank Con for a good debate.

I don't dispute that making of the hockey stick was honestly undertaken. All those involved were, I believe, convinced they were correct. I do question the peer review process, a point that I raised in response to Con's objection that results of the Senate panel were not subjected to peer review. That objection is not to the undertaking of making the hockey stick, which was completed prior to 2000, but rather to the later corruption of the peer review process. Of course, the Wegman work stands on it's merits.

Honesty was the first of four criteria Con offered for science to judged "good." I'm not sure the list is exhaustive, but I'll use it to summarize the debate.

Standard Techniques were not used

The original hockey stick paper was never reviewed by a scientist qualified to check the statistical methodology. The Senate committee investigation put the paper reviewers on record as admitting they were not qualified. No one on Mann Team was associated with anyone versed in mainstream statistics.

Te hockey stick analysis relied heavily on bristlecone data, which the scientific literature states are should not be used as a temperature proxy.

A panel of three expert statisticians, headed by Prof. Wegman, found that the statistical techniques used in the derivation of the hockey stick were wrong, and the critics were correct. Wegman specifically called the hockey stick "bad science."

Con suggests that von Storch fond the errors "minor." He found one aspect minor, but, as Wikipedia summaries,"In late 2004 [von Storch's] team published an article in Science that tested multiproxy methods such as those used by Mann, Bradley and Hughes, 1998, often called MBH98, or Mann and Jones to obtain the global temperature variations in the past 1000 years. The test showed that the method used in MBH98 would inherently underestimate large variations had they occurred; ..." [12. http://en.wikipedia.org... Of course the Mann Team continues to dispute von Storch's assessment, but von Storch and the Senate panel are clearly the most qualified practitioners of the specialty of statistical analysis.

Wegman and von Storch agreed on the result of the error in the Mann analysis. The hockey stick has a flat part showing that climate never varied significantly until the recent "blade" part of the graph. The blade part, showing recent temperature rise was not disputed; in fact proxies were not used for that part of the graph. So when Wegman says the hockey stick disappears, he means the long flat part becomes irregular. The error was that past climate variation were suppressed.

In the last round, Con showed a recent revised graph in which some of the past temperature variations are shown. It's good that at least some errors have been corrected, but our debate is about the hockey stick graph presented in the 2000 IPCC report, shown in my R2, that eliminated all natural variations in climate. Note that even the more recent version of the graph does not show the last decade, when temperature have been flat.

The hockey stick does not show robust findings

The purpose of the hockey stick graph was to show that there had been no natural variations in climate for a thousand years and that CO2-induced global warming was causing an exponential increase in temperatures. The result allegedly showed that mankind was facing a climate crisis requiring immediate government action. The hockey stick theory was subsequently tested by comparison the temperatures that occurred subsequent to it's publication in 1998. It failed completely. Temperatures were supposed o increase exponentially, but they bounced around a constant level. If there was any trend at all it was slightly downward.

As a work of analysis, McKitrick and Wegman and others showed that putting trendless noise into the hockey stick processing produced a hockey stick. A "robust" method, in scientific terms means that the method works accurately under a variety of conditions, When the supplied data has to trend, it should not produce one. that's inaccurate. therefore is fails as an analytical technique.

Con maintains that Medieval Warm Period and the Little Ice Age might be compatible with the hockey stick. The idea s that they might have been local events, akin to weather rather than climate. he hockey stick purports to show that whatever natural forces affect climate, they have not operated for a thousand years. But the MWP and the Little Ice Age are documented to have persisted over very large areas for hundreds of years. More studies show they were worldwide.

The hockey stick was not reproducible

Mann fought to keep both the data and the processing method secret. Good science requires tat both be given to other scientists so the results can reproduced. With enormous pressure, Mann gave up much of his data and enough clues about the processing method so that other could show the errors in the method. the exact processing algorithm is stills as proprietary to the investigators.

Another test of how robust the findings are is to apply standard principle component analysis to the data and see if the hockey stick emerges. It does not.

Con claimed that because others on the Mann Team have produced hockey stick results, the results are reproducible. McKitrick showed that in fact the results were not independent, but relied on the e faulty tree ring data and faulty processing techniques.

What is happening is not dishonesty, but rather "group think." Each person the Mann Team believes their analysis to be correct and they confirm each other in that opinion. It's a mild version of adherence to a religious doctrine by a core group of believers; none are dishonest, but they cannot be impressed by any objection. Con charges that Wegman working on finding the closeness of the group first, then applied it to the critique. It was the other way around. The Network Analysis was subsequent to the Senate Committee work, as the dates on the references show. What the network analysis a likely reason for the mutual confirmation of bad science, not the fundamental errors which were previously revealed.

Comparing Experts

Expert opinion is critical to the evaluation of this debate. It is not the case that when scientists disagree, one is free to choose who to believe. Science is highly specialized, and statistics is difficult specialty. McKitrick, Wegman and the other two panellists on the Senate committee and von Storch are level of expertise available in the subject. While Mann et al use statistical methods, they neither had expertise themselves nor did they not seek it in review. (I seek a colorful analogy. Mann vs. Wegman is like Gilbert Godfried vs. Chuck Norris or the Girl Scouts vs. the Oakland Raiders or ... never mind.) Wegman was distinguished as president of the American Statistical Association, Von Storch received the IMSC achievement award at the International Meetings on Statistical Climatology in Edinburgh in 2010, to "recognize his key contributions to statistical downscaling, reconstruction of temperature series, analyses of climatic variability, and detection and attribution of climate change." [12]

Con can do no more than to quote the arguments made by the Mann Team as to why they are correct and the experts are wrong. As noted, a degree in climate science doesn't require a single course in statistical analysis.

Summary

Con says that the problem I have with the hockey stick is that it doesn't show what I want it to. The problems I have are that the data and algorithms were concealed, it was not peer reviewed by qualified statisticians, it has been found to be incorrectly derived by six highly qualified experts in statistics. It also found by experts to make hockey sticks out of trendless noise, and to suppresses past climate variations. Most importantly, it's prediction of an an exponential rise in temperature in the past decade was completely false. That makes it bad science.

Debate Round No. 4
87 comments have been posted on this debate. Showing 1 through 10 records.
Posted by citizenschallenge 3 years ago
citizenschallenge
OK too distracted - he's my last correction, though I got a couple other typos hiding in there -

to repeat:

----------------------------------------------------------------------
Roy writes: My opponent in the debate Is a PhD in chemistry and actually understands a good deal of the statistics and science involved. The debate was pathetic because you guys are operating on a much higher plane ... right?
~ ~ ~

Not at all - he's simply not versioned in the art of the jujitsu political debate -

Thaumaturgy kept thinking in terms of a constructive scientific debate with both parties having learning as the main goal.

Thaumaturgy's information was solid, his responses to your fancy disingenuous footwork, not so good >>>
but, that is not to disparage his knowledge or what he shared -

He could teach you (us) a lot, if only you weren't so focused on avoiding his information.
Posted by citizenschallenge 3 years ago
citizenschallenge
Roy writes: Let's assume that the hockey stick is good science, and that nothing has affected climate until recent times. So what does that say about CO2 as a factor in climate? I'll help you with some choices: (a) CO2 now completely dominates climate, because all other possible explanations have been removed, (b) it means climate is driven by many factors, ... or what?
~ ~ ~

But the thing is - NO CLIMATOLOGIST EVER claimed: "that nothing has affected climate until recent times."

You are building your own straw man to tear down with ease.
~ ~ ~

NO CLIMATOLOGIST EVER claimed: "CO2 completely dominates climate."
The point your bias won't allow you to face is that Humanity completely dominates recent increases in atmospheric greenhouse gas levels.
And we have injected so much of them into our thin atmosphere that they are beginning to overwhelming other 'natural' factors in the system.
~ ~ ~

Yes, there are many components, elements and factor involved in to our global heat distribution engine... are you disputing that?

~ ~ ~ ~ ~ ~ ~

My opponent in the debate Is a PhD in chemistry and actually understands a good deal of the statistics and science involved. The debate was pathetic because you guys are operating on a much higher plane ... right?
~ ~ ~

Roy writes: Not at all - he's simply not versioned in the art of the jujitsu political debate -

Thaumaturgy kept thinking in terms of a constructive scientific debate with both parties having learning as the main goal.

Thaumaturgy's information was solid, his responses to your fancy disingenuous footwork, not so good >>>
but, that is not to disparage his knowledge or what he shared -

He could teach you a lot, if only you weren't so focused on avoiding his information.
Posted by citizenschallenge 3 years ago
citizenschallenge
Roy writes: "For example, we have a very good history of sunspot activity and that history correlates very closely with both the MWP and the LIA."
~ ~ ~

Why not point out how that correlation has broken down in the few decades?
Or that CO2 and other greenhouse gases are about a third greater these days than they were back then - thus overwhelming the impact of the sun's micro fluctuations in energy output.

Indeed, you have demonstrated without apparently knowing it - why we know today's warming situation is qualitatively and quantitatively different from what was happening back then.
And why this science skeptical obsession on the MWP is a disingenuous diversion from what we, collectively, need to be focusing on.
~ ~ ~ ~ ~ ~ ~

May I suggest some more substantive information:
http://www.skepticalscience.com...

Like Foster and Rahmstorf (2011), Lean and Rind (2008) performed a multiple linear regression on the temperature data, and found that while solar activity can account for about 11% of the global warming from 1889 to 2006, it can only account for 1.6% of the warming from 1955 to 2005, and had a slight cooling effect (-0.004"C per decade) from 1979 to 2005.
{...}
Other studies on solar influence on climate
This conclusion is confirmed by many studies finding that while the sun contributed to warming in the early 20th Century, it has had little contribution (most likely negative) in the last few decades:
Huber and Knutti (2011):
Erlykin 2009:
Benestad 2009:
Lockwood 2008:
Lean 2008:
Lockwood 2008:
Ammann 2007:
Lockwood 2007:
Foukal 2006
Scafetta 2006
Usoskin 2005
Solanki 2004
Haigh 2003
Stott 2003
Solanki 2003
Lean 1999
Waple 1999
Frolich 1998"
Posted by citizenschallenge 3 years ago
citizenschallenge
opps, those dastardly typos just won't leave me alone.

~~~
use
~~~
The graph -
as the IPCC presents it http://www.ipcc.ch...
~~~
learned
~~~
Posted by citizenschallenge 3 years ago
citizenschallenge
Roy writes: "Very good, that's getting there. The hockey stick showed that the MWP did not exist and the LIA did not exist. {1} So nothing happened in climate history until the period from about 1980 to 1998. {2} So now tell me, is this correct or incorrect? {3} Is it true that nothing happened in climate history in the previous thousand years?"{4}
~ ~ ~ ~ ~ ~ ~

{1} Nonsense! Various "hockey stick(s)" do indeed reflect both the MWP and LIA. Keep in mind not every "hockey stick" presented as "global" is in fact "global" many are based on regional proxies, thus reflect a regional record.

One of the frauds denialists often us is to misrepresent exactly what's what regarding the graphs they are sharing. Here's the graph as the IPCC resents it:
http://www.ipcc.ch...
~ ~ ~

{2} Just voicing that sort of untruth reveals you to be an insincere participant and that this "debate" has nothing to do with learning or solving problems - it's all just a rhetorical game, disconnected from what's actually happening upon our globe.

Want to learn what scientists have learn? Then go to some serious sources of information:
http://www.aip.org...
~ ~ ~

{3} Your assertion is false.

{4} Climatologists have been very aware of our planet's dynamic character and in fact they even understand how our atmosphere evolved into the life sustaining creature it is today. They also understand that our climate is a complex global heat distribution engine involving many elements and a rich history
~ ~ ~

Perhaps the most hideous aspect about the past couple decades of moribund economically/politically biased AGW "debate" - is the ease with which "skeptics" misrepresent what the scientists are actually saying.

It is sad to see Roy following that tradition.
Posted by RoyLatham 3 years ago
RoyLatham
@cit, You have not made a single point that I can find. What you are doing is like debating religion by saying "go read and study the Bible and all your questions will be answered." You need to make a factual claims. A general slander is not a factual claim. Start with the claim, "The hockey stick proves that CO2 currently dominates climate." or "The MWP does not exist." or whatever you think the hockey proves.
Posted by RoyLatham 3 years ago
RoyLatham
Cit said, " Because it demonstrated an increase in temperature anomaly during recent periods that was unprecedented, on a global scale, in recent geological history."

Very good, that's getting there. The hockey stick showed that the MWP did not exist and the LIA did not exist. So nothing happened in climate history until the period from about 1980 to 1998. So now tell me, is this correct or incorrect? Is it true that nothing happened in climate history in the previous thousand years?

For example, we have a very good history of sunspot activity and that history correlates very closely with both the MWP and the LIA. So therefore the hockey stick told us that sunspot activity has no effect on climate ... right? Or is that wrong? since nothing has happened in the past thousand years, clearly there is no Pacific Decadal Oscillation or any other natural climate cycle. There is no sign of it ever occurring in the past, right?

Let's assume that the hockey stick is good science, and that nothing has affected climate until recent times. So what does that say about CO2 as a factor in climate? I'll help you with some choices: (a) CO2 now completely dominates climate, because all other possible explanations have been removed, (b) it means climate is driven by many factors, ... or what?

My opponent in the debate Is a PhD in chemistry and actually understands a good deal of the statistics and science involved. The debate was pathetic because you guys are operating on a much higher plane ... right?

How is it possible to have read the debate and still ask what the standard methods of analysis are or what mistakes Mann et al made in the analysis?
Posted by citizenschallenge 3 years ago
citizenschallenge
Roy writes: "Neither one of you have read the debate let alone any of the actual articles you point to, have you? "
Bull poop - thing is ~ the debate was sort of pathetic.
But, now we are in the comments section so let's deal with it.
~ ~ ~
Roy writes: " You keep asking questions that were answered in the debate. You want me to read Mann's website (realclimate), find out what his arguments are, construct your case for you, then refute. If that is the way you think that debate works, then I invite you read McIntyre's refutations at climateaudit.org and work it out for yourself."
~ ~ ~

Actually, guess I make the mistake of thinking in terms of a genuine intellectual debate

one where the object is to teach each other perspectives we were not aware of and to help solve puzzles.

Where both side retain a certain skepticism towards their own notions
and are willing to put those notions to the test.

WHAT DO YOU THINK OF THAT SORT OF "DEBATE" ?

So far, all you, Roy, have done is dance around issues > and ignore every specific claim/charge I've made.

So back off with the high and mighty facade !

Want a debate >
start getting real about responding to your opponent's points/issues !

Rather than making an art-form out of avoiding them.
==========================================

You have done nothing to help understand or learn anything about your "skeptical" arguments except lot's of deflection, and misrepresentation. And it's obviously based on some high octane "conspiracy ideation" - lacking any substantive evidence.

Produce evidence. . .
or let's talk basic laws of physics.
Posted by Citrakayah 3 years ago
Citrakayah
No, that's not what I did at all.

1. Because it demonstrated an increase in temperature anomaly during recent periods that was unprecedented, on a global scale, in recent geological history.
2. See above.
Posted by RoyLatham 3 years ago
RoyLatham
@Cit, The way it works in debate is that you make a specific claim of fact, then you cite a reference supporting that claim. You gave a reading list from which I was supposed to figure ought what accusation you were making as well as their replies.

Answer the question?: Why was the hockey stick the centerpiece of the 2000 IPCC report? What was it purported to show? If you cannot answer such straightforward questions, I think you are disqualified from discussing the topic.
6 votes have been placed for this debate. Showing 1 through 6 records.
Vote Placed by Man-is-good 5 years ago
Man-is-good
ThaumaturgyRoyLathamTied
Agreed with before the debate:--Vote Checkmark0 points
Agreed with after the debate:--Vote Checkmark0 points
Who had better conduct:--Vote Checkmark1 point
Had better spelling and grammar:--Vote Checkmark1 point
Made more convincing arguments:-Vote Checkmark-3 points
Used the most reliable sources:--Vote Checkmark2 points
Total points awarded:03 
Reasons for voting decision: An interesting debate. While Roy could have demonstrate more in the final phase of the round, his contentions on the issues of Mann's work (the reliance on bristlecone data, the flaws in Mann's own procedure as well as his failure to submit it to public review, the lack of experience in the field of statistical analysis, and so forth) were not fully refuted nor shown to be false and such, among others, weighed on Pro's side.
Vote Placed by innomen 5 years ago
innomen
ThaumaturgyRoyLathamTied
Agreed with before the debate:--Vote Checkmark0 points
Agreed with after the debate:--Vote Checkmark0 points
Who had better conduct:--Vote Checkmark1 point
Had better spelling and grammar:--Vote Checkmark1 point
Made more convincing arguments:-Vote Checkmark-3 points
Used the most reliable sources:--Vote Checkmark2 points
Total points awarded:03 
Reasons for voting decision: Great debate, difficult to judge, but I found Roy's objection to be sound and not well refuted. Whether or not the results were what Roy wanted to see, the reasons for there being sufficient reason to doubt its results.
Vote Placed by 16kadams 5 years ago
16kadams
ThaumaturgyRoyLathamTied
Agreed with before the debate:-Vote Checkmark-0 points
Agreed with after the debate:-Vote Checkmark-0 points
Who had better conduct:--Vote Checkmark1 point
Had better spelling and grammar:--Vote Checkmark1 point
Made more convincing arguments:Vote Checkmark--3 points
Used the most reliable sources:Vote Checkmark--2 points
Total points awarded:50 
Reasons for voting decision: As con pointed out, the hockey stick has been reproduced by other scientists. CON also showed the people who made the hockey stick really did believe its findings and used proper scientific marriage. Although I think the hockey stick is BS, con had a good case and convinced me (when comparing cons and pros arguments) that the hockey stick was good science. CON proved it was good science, pro did not win this debate, though I agree with him anyway. Counter vote source point, explain it boone.
Vote Placed by tBoonePickens 5 years ago
tBoonePickens
ThaumaturgyRoyLathamTied
Agreed with before the debate:-Vote Checkmark-0 points
Agreed with after the debate:-Vote Checkmark-0 points
Who had better conduct:--Vote Checkmark1 point
Had better spelling and grammar:--Vote Checkmark1 point
Made more convincing arguments:-Vote Checkmark-3 points
Used the most reliable sources:-Vote Checkmark-2 points
Total points awarded:05 
Reasons for voting decision: In his last response, Con did not directly address all of Pro's point especially his crucial points. Great debate! Roy is great as always and Thaumaturgy was also very good. Learned a few new things about Global Warming/Climate Change.
Vote Placed by FourTrouble 5 years ago
FourTrouble
ThaumaturgyRoyLathamTied
Agreed with before the debate:--Vote Checkmark0 points
Agreed with after the debate:--Vote Checkmark0 points
Who had better conduct:--Vote Checkmark1 point
Had better spelling and grammar:--Vote Checkmark1 point
Made more convincing arguments:Vote Checkmark--3 points
Used the most reliable sources:Vote Checkmark--2 points
Total points awarded:50 
Reasons for voting decision: I'm not convinced by either side. Roy argues the Hockey Stick is bad science because it was not reviewed by "qualified statisticians." On the other hand, Thaumaturgy argues the Hockey Stick can be established as "good science" because it went through peer review. Roy counters by questioning the integrity of the "peer review" process undergone by the Hockey Stick. Arguments presented by both sides are appeals to authorities, nothing more. RFD continued in comments.
Vote Placed by Greyparrot 5 years ago
Greyparrot
ThaumaturgyRoyLathamTied
Agreed with before the debate:-Vote Checkmark-0 points
Agreed with after the debate:-Vote Checkmark-0 points
Who had better conduct:--Vote Checkmark1 point
Had better spelling and grammar:--Vote Checkmark1 point
Made more convincing arguments:-Vote Checkmark-3 points
Used the most reliable sources:--Vote Checkmark2 points
Total points awarded:03 
Reasons for voting decision: Con did not refute the bad peer evaluation of the Hockey stick study.