McKintyre & McKitrick publish again !

12 views
Skip to first unread message

peroxisome

unread,
Jan 27, 2005, 3:05:46 PM1/27/05
to
A new paper in Energy and Environment
http://www.multi-science.co.uk/mcintyre-mckitrick.pdf
A new paper in Geophysical Research Letters
http://www.climate2003.com/pdfs/2004GL012750.pdf

So, apparently in contradiction to much of the verbal abuse spouted
about these authors, M&M's work is sufficiently good to pass
peer-review in Geophysical Research Letters. Does that make them bona
fide scientists ?

Couldn't resist the spectacle of Michael Mann making some pretty
undignified commentary about M&M; and he imagines that no-one will
notice his own vested interest in making these comments.
http://www.realclimate.org/index.php?p=111#more-111

per

David Ball

unread,
Jan 28, 2005, 9:08:30 AM1/28/05
to
On 27 Jan 2005 12:05:46 -0800, "peroxisome" <perox...@ntlworld.com>
wrote:

LOL. If you say so, Per. The realclimate link is quite right
and you, as usual, don't have a clue. BTW, are you affiliated in some
way with M&M? You only seem to make an appearance here when they
publish their bogus material.

peroxisome

unread,
Jan 28, 2005, 12:12:15 PM1/28/05
to
David Ball wrote:
> LOL. If you say so, Per. The realclimate link is quite right
> and you, as usual, don't have a clue. BTW, are you affiliated in some
> way with M&M? You only seem to make an appearance here when they
> publish their bogus material.

So david, I can't remember but I would be fairly sure that you were one
of the guys who made the case that M&M's work was not to be trusted
because (a) it wasn't in a "real" peer-reviewed journal (b) M&M aren't
"real" environmental scientists. Isn't there a feeling of eating crow,
now that M&M have published in a bona fide environmental journal.

And what is even better, their peer-reviewed comments about MBH98 !
Since it is in the peer-reviewed literature, it must be true, no ? Or
are you in the camp that is now backing quickly away from MBH98 ?
yours
per

w...@bas.ac.uk

unread,
Jan 28, 2005, 1:17:57 PM1/28/05
to
peroxisome <perox...@ntlworld.com> wrote:

>David Ball wrote:
>> BTW, are you affiliated in some
>> way with M&M? You only seem to make an appearance here when they
>> publish their bogus material.

You don't seem to have replied to Davids point.

-W.

--
William M Connolley | w...@bas.ac.uk | http://www.antarctica.ac.uk/met/wmc/
Climate Modeller, British Antarctic Survey | Disclaimer: I speak for myself
I'm a .signature virus! copy me into your .signature file & help me spread!

Lloyd Parker

unread,
Jan 28, 2005, 11:00:57 AM1/28/05
to
In article <lohkv055a7jmeuac8...@4ax.com>,

Intresrtingly, his link doesn't take you to GRL or the AGU. Going there
and doing their "search issues back to 1994" returns the following for
either M:

"No records found"

Thomas Palm

unread,
Jan 28, 2005, 6:09:10 PM1/28/05
to
lpa...@emory.edu (Lloyd Parker) wrote in news:cte96a$iqn$3
@puck.cc.emory.edu:

http://www.realclimate.org/index.php?p=111

"MM however, continue to promote false and specious claims. McIntyre and
McKitrick (2005), in a paper they have managed to slip through the
imperfect peer-review filter of GRL, now simply recycle the very same false
claims made by them previously in their comment on MBH98 that was rejected
by Nature."

If Mann says the paper exist, I believe it does, even if it is in an issue
that isn't out yet.

Steve Schulin

unread,
Jan 28, 2005, 9:14:42 PM1/28/05
to
In article <1106856346.6...@f14g2000cwb.googlegroups.com>,
"peroxisome" <perox...@ntlworld.com> wrote:

The last couple of days has seen extensive coverage of the "Hockey
Stick" in Canada's National Post and its Financial Post. Here are four
articles, including one from front page yesterday:

---sbs--- ARTICLE 1 OF 4

Source: Marcel Crok (editor of Natuurwetenschap & Techniek, a Dutch
science magazine), "Breaking the hockey stick: The famous graph that
supposedly shows that recent temperatures are the highest in a thousand
years has now been shown by careful analysis to have been based on
faulty data", Financial Post (Canada), January 27, 2005, p. FP11

Few people dispute that the earth is getting warmer, but there are
people -- so-called "climate skeptics" -- who question whether the
change is historically unique and whether it is the result of human
activity. These skeptics are generally outsiders, reviled by "true"
climate researchers.

On the one hand, Michael Mann, the first author of the two noted
hockey-stick papers (in Nature in 1998 and in Geophysical Research
Letters in 1999), is the unofficial king of climate research. In 2002,
Scientific American included him as one of the top 50 visionaries in
science. On the other hand, the two Canadian skeptics are outsiders:
Ross McKitrick is a professor of economics and Stephen McIntyre is a
mineral exploration consultant -- which Mann likes to call a conflict of
interest.

Climate skeptics are most prolific on the Internet, a platform for
novices, the scatterbrained and the experienced alike. Not surprisingly,
the climate researchers whom we consulted (predominantly Dutch) presumed
the work of the two Canadians to be unconvincing. We at Natuurwetenschap
& Techniek were initially skeptical about these skeptics as well.
However, McIntyre and McKitrick have recently had an article accepted by
Geophysical Research Letters -- the same journal that published Mann's
1999 article. This, together with the positive responses of the referees
to that article, quickly brought us around.

Even Geophysical Research Letters, an eminent scientific journal, now
acknowledges a serious problem with the prevailing climate
reconstruction by Mann and his colleagues. This undercuts both Mann's
supposed proof that human activity has been responsible for the warming
of the earth's atmosphere in the 20th century and the ability to place
confidence in the findings and recommendations of the influential
Intergovernmental Panel on Climate Change (IPCC). The political
implication is a serious undermining of the Kyoto Protocol with its
worldwide agreements on reducing emissions of carbon dioxide and other
greenhouse gases.

In their two seminal papers, Mann and his colleagues purported to
reconstruct Northern Hemisphere temperatures for the last thousand
years. Since 1000, temperatures gradually decreased (the shaft of the
hockey stick), only to increase sharply from 1900 onwards (the
blade).The implication is obvious: Human interference caused this trend
to change. McIntyre and McKitrick merely attempted to replicate this
oft-quoted study. In doing so, they identified mistake after mistake.
They also discovered that this fundamental reconstruction had never
actually been replicated by the IPCC or any other scientist. In their
replication, basically derived from the same data, temperatures in the
15th century were just as high as they are today -- an outcome that
takes the edge off the alarmist scenario of anthropogenic global
warming. The criticism by the Canadians is mostly technical in nature:
They claim that Mann and his colleagues have misused an established
statistical method -- principal component analysis (PCA) -- so that
their calculations simply mined data for hockey-stick shaped series and
that Mann's results are statistically meaningless.

The scientists that we consulted did not immediately recognize the
implications of Mann's eccentric method, suggesting the possibility he
himself may not have been aware of the apparent mistake. However, in
response to our inquiries, Mann denies any errors and rejects any
criticism in strident terms.

Up to January, 2005, none of McIntyre and McKitrick's findings had been
published by major scientific journals. Thus, in the opinion of
established climate researchers, there was no reason to take them
seriously. Climate researchers were quite comfortable in their consensus
and repeatedly referred to this "consensus" as a basis for policy. The
official expression of the consensus comes from the IPCC. This group,
under the flag of the United Nations, comes out with a bulky report
every five years on the state of affairs in climate research. Hundreds
of climate researchers from every corner of the world contribute to it.
In the third report in 2001, Mann himself was a lead author of the
chapter on climate reconstructions.

Mann's hockey-stick graph was the only climate reconstruction to make it
to the IPCC "Summary for Policy Makers." Its conclusion read: "It is
likely that, in the Northern Hemisphere, the 1990s was the warmest
decade and 1998 the warmest year during the past thousand years." This
statement has been used by governments the world over to promote the
Kyoto Protocol.

Stephen McIntyre first came across the hockey stick in late 2002. The
Canadian government used the graph to promote the Kyoto treaty. McIntyre
explains by telephone: "When I first saw the graph, it reminded me of
dot.com profit forecasts, which were also hockey sticks. It was a
compelling graphic, but, in the mineral exploration industry, my own
field, compelling graphics are one of the techniques used to interest
investors in financing mineral exploration."

McIntyre has scrutinized promotional graphics and large data sets for
years. "From my own experience, I thought that the graphic looked
excessively promotional," he said. "A trick of mining promoters is to
overemphasize some isolated results. I wondered if this had been the
case with the hockey stick as well. I thought that it would be
interesting to look at the data underlying this graphic -- as though I
was looking at drill core from an exploration project. The interest was
simply personal; I had no intention of writing academic articles and
never expected what happened afterward."

McIntyre sent an e-mail to Michael Mann in spring 2003, asking him for
the location of the data used in his study. "Mann replied that he had
forgotten the location," he said. "However, he said that he would ask
his colleague Scott Rutherford to locate the data. Rutherford then said
that the information did not exist in any one location, but that he
would assemble it for me. I thought this was bizarre. This study had
been featured in the main IPCC policy document. I assumed that they
would have some type of due-diligence package for the IPCC on hand, as
you would have in a major business transaction. If there was no such
package, perhaps there had never been any due diligence on the data, as
I understood the term. In the end, this turned out to be the case. The
IPCC had never bothered to verify Mann, Bradley and Hughes' study."

Despite billions of dollars spent on climate research, academic and
institutional researchers had never bothered to replicate Mann's work
either. In 2003, McIntyre tackled the job and, from an unusual hobby,
the task has since grown to become almost a full-time occupation. On an
Internet forum for climate skeptics, he met Ross McKitrick, professor of
economics at the University of Guelph, just outside of Toronto. Since
meeting in person in September of 2003, the two have been working on the
project together. McIntyre does most of the research and McKitrick asks
questions and assists in the writing of papers.

Reliable temperature measurements have only been available since around
1850. Before this period, researchers have to rely on indirect
indicators, or "proxies," such as tree rings, ice cores, sedimentary
layers and corals, of which tree rings are the most commonly used.
Scientists studying tree rings will summarize the growth at one site
into a single index or chronology, which might start, for instance, at
1470 and end at 1980.

Mann's study is the best known of the multi-proxy studies. For a
realistic reproduction of the temperature in the entire Northern
Hemisphere, Mann and others attempt to have a relatively even geographic
distribution of proxies. This posed a difficulty. The majority of
proxies were tree-ring "chronologies," especially from the U.S.
Southwest. To achieve more even geographic distribution (and avoid being
swamped by North American tree-ring data), Mann used principal component
analysis to summarize networks of tree-ring sites, the largest of which
was in North America. The 1998 article reported the use of 112 proxy
series.

However, for some reason, Mann and his colleagues did not accurately
document the data they had actually used. McIntyre says: "Of the series
and sites listed in the original documentation, 35 were not actually
used. To further confuse matters, in November, 2003, over five years
after publication, Mann stated that they had actually used 159 series,
instead of the 112 mentioned in his Nature article or in Rutherford's
e-mail."

We decided to ask Dr. Eduardo Zorita of the GKSS Research Center in
Geesthacht, Germany, who has also recently examined the calculations
behind the hockey stick. His response: "This is the first time that I've
heard of the number 159. In our analysis of the hockey stick, we do not
use the actual data, but a series of pseudo proxies, proxies we take
from our simulations. We have always assumed 112 pseudo proxies."

McIntyre decided to check the PC calculations for tree-ring networks, by
doing fresh calculations with original data from the World Data Center
for Paleoclimatology (WDCP). His results were very different from
Mann's. He and McKitrick then sent the full data set (originally
downloaded from Mann's FTP site from the address provided by Rutherford)
back to Mann for confirmation that this was actually the data set used.
In response, Mann stated that he did not have the time to answer this or
any other request.

McIntyre and McKitrick then tried to replicate Mann's Northern
Hemisphere temperature calculations from scratch. The results largely
coincided with the hockey stick, except for the 15th century, when their
calculated temperatures were considerably higher than Mann's and were
even higher than corresponding estimates in the 20th century. McIntyre
emphasized: "We did not claim to have discovered a warm medieval period;
we only stated that, given the many defects in the study, it could not
be used to assert that the 1990s were the warmest years of the past
millennium."

Their findings were published in the interdisciplinary journal Energy
and Environment in October, 2003. Mann's early responses were quite
unexpected. McIntyre: "Mann stated that we had used the wrong data and
somehow we failed to notice errors in the data. This was outrageous, as
we had downloaded the data from his own FTP site from the location
provided by his own colleague, Scott Rutherford; we had described
countless errors in great detail and had re-collated over 300 series to
avoid these problems. Now, according to Mann, we should have taken the
data off a different address at his FTP site, but this new address had
never been mentioned in any publication or even on his own Web site."

A little later, Mann and his colleagues said that they had used a
step-wise procedure to deal with missing data, while McIntyre and
McKitrick had not. McIntyre says: "This was when the figure of 159
series first appeared. There is no mention of this stepwise method in
his Nature article. A PCA calculation fails if there is any missing
data."

But McIntyre and McKitrick were most intrigued by the attribution by
Mann and his colleagues of the difference in results to three "key
indicators" -- most notably a North American data series -- showing
that, with different handling of these three series, they also obtained
high early-15th-century results. McIntyre and McKitrick decided, for the
time being, to concentrate on the years 1400 to 1450, the period with
the biggest discrepancies.

"Mann's own response showed that his temperature reconstruction for the
first half of the 15th-century depended on [data] from the North
American network. We decided to find out everything that we could about
these three indicators."

Because of the discrepancy between the published methodology and the
methods actually used, the ambiguity over the data sets, and the sudden
claim that 159 series had to be used, McIntyre and McKitrick requested
original source code from Mann in order to fully reconcile their
results. Mann refused. But McIntyre did make an interesting find at
Mann's FTP site -- a Fortran program of about 500 lines for the
calculation of tree-ring series, virtually the only source code on the
entire site. They carefully studied the script and found a highly
unusual procedure that had not been mentioned in the Nature article.

McIntyre says: "The effect is that tree-ring series with a hockey-stick
shape no longer have a mean of zero and end up dominating the first
principal [data] component; in effect, Mann's program mines for series
with a hockey-stick shape."

At our request, Dr. Mia Hubert of the Katholieke Universiteit Leuven in
Belgium, who specializes in robust statistics, checked to see if Mann's
unusual standardization influenced the climate reconstruction. She
confirms: "Tree rings with a hockey-stick shape dominate the PCA with
this method."

McIntyre and McKitrick decided to perform another check. Using computer
simulations of so-called "red noise," they generated networks of
artificial tree-ring data over the period of 1400 to 1980. Red noise is
commonly used in climatology and oceanography. McIntyre says: "If we
used Mann's method on red noise, we consistently obtained hockey sticks
with an inflection at the start of the 20th century. We have repeated
the simulation thousands of times and in 99% of the cases, the result of
the PCA was a hockey stick."

Mann's climate reconstruction methodology would have yielded a
hockey-stick graph from any tree-ring data set entered into the model,
as long as there is sufficient red noise.

The two Canadians are no longer just one voice crying in the wilderness.
On Oct. 22, 2004, in Science, Dr. Zorita and his colleague Dr. Hans von
Storch, a specialist in climate statistics at the same institute,
published a critique of a completely different aspect of the 1998
hockey-stick article. After studying McIntyre's finding at our request,
Von Storch agrees that "simulations with red noise do lead to hockey
sticks. McIntyre and McKitrick's criticism on the hockey stick from 1998
is entirely valid on this particular point."

GRAPHIC: Chart/Graph: McIntyre & McKitrick, National Post; THE HOCKEY
STICK RECONSTRUCTED: Northern Hemisphere temperatures for the last 600
years: Corrected temperature reconstruction by McIntyre and McKitrick,
IPCC temperature reconstruction by Mann: (See print copy for complete
chart/graph.); Graphic/Diagram: The Northern Hemisphere.

Copyright 2005 National Post. All Rights Reserved

---sbs--- ARTICLE 2 OF 4

Source: Terence Corcoran, "Let science debate begin", Financial Post
(Canada), January 27, 2005, p. FP11

For some time now this page has been publishing comment on The Hockey
Stick, the central piece of scientific evidence for the United Nation's
claim that the world is warmer now than at any time in the last 1,000
years. Today we begin a major two-part investigation that delves deeper
into the foundations for what may well be the most important economic,
scientific and business graphic in world history.

Created by Michael Mann, currently assistant professor, department of
environmental science, University of Virginia, the hockey stick purports
to plot temperatures in the Northern Hemisphere back 1,000 years. For
the most part, the line appears relatively stable leading up to the 20th
century, when it turns sharply upward, forming the blade of the hockey
stick.

The hockey-stick image has appeared in countless documents and hundreds
of speeches. The opening graphic in the recently-published Arctic
Climate Impact Assessment report reproduces the Mann chart as the main
springboard to hundreds of pages on climate risks in the Arctic. It is
also the core justification for the Kyoto Protocol, which comes into
effect on Feb. 16.

Until now, criticisms of the hockey stick have been dismissed as fringe
reports from marginal global warming skeptics. Today, however, the
critical work of two Canadian researchers, Ross McKitrick, an economics
professor at Guelph University, and Toronto consultant Stephen McIntyre,
will be published by Geophysical Research Letters, the prestigious
journal that published one of the early versions of Michael Mann's
1,000-year tracking of Northern Hemisphere temperatures,

Publication in Geophysical Research sets McIntyre and McKitrick's
analysis and conclusions in direct opposition to the Mann research.
Their criticism can no longer be dismissed as if it were untested
research posted on obscure Web sites by crank outsiders. Their work is
now a full challenge to the dominant theme of the entire climate and
global warming movement.

The story of McIntyre and McKitrick's research, and their attempt to
recreate the hockey stick, is the subject of the special two-part
commentary that begins today. Written by Marcel Crok, an editor with the
Dutch science magazine Natuurwetenschap & Techniek, the article
chronicles the mystery behind the unraveling of the hockey stick.

It is a story filled with intrigue, conflict and amazing facts about how
science is made, especially climate science. It's also a story about the
inner workings of science journals and, especially, the UN panel on
climate change that is at the heart of climate politics and the
economics of the Kyoto Protocol. Above all, the story threatens to rock
the foundations of climate science.

Rob van Dorland of the Royal Netherlands Meteorological Institute
believes the McIntyre and McKitrick paper in Geophysical Research
justifies an investigation by the UN's International Panel on Climate
Change (IPCC). Van Dorland is a lead author on the next IPCC report due
in 2007. "It is strange," he said, "that the climate reconstruction of
Mann has passed both peer review rounds of the IPCC without anyone ever
really having checked it. I think this issue will be on the agenda of
the next IPCC meeting in Peking in May."

Other scientists around the world have yet to weigh in on the
Geophysical Research paper and another work just published by McIntyre
and McKitrick in another science magazine, Environment and Energy. In
that paper, posted yesterday at www.multi-science.co.uk, McIntyre and
McKitrick also raise important questions about the methods and practices
of scientists and science journals whose material becomes the basis for
public policy.

Climate science, long thought settled by many if not most Canadians and
the rest of the world, is anything but. Let the debate begin.

Copyright 2005 National Post. All Rights Reserved

---sbs--- ARTICLE 3 OF 4

Source: James Cowan, "Canadians find flaw in Kyoto 'hockey stick':
Global warming debate", National Post (Canada), January 27, 2005, p. A1

A pivotal global warming study central to the Kyoto Protocol contains
serious flaws caused by a computer programming glitch and other faulty
methodology, according to new Canadian research.

Ross McKitrick, an economics professor at Guelph University, and Stephen
McIntyre, a mineral exploration consultant, refute the claim
temperatures have sharply increased in the past century, saying
prevailing climate research is wrong. Their study is published today in
Geophysical Research Letters, one of two prominent journals that in 1998
published the research they are now challenging.

In particular, the researchers challenge a study by University of
Virginia professor Michael Mann, which used tree-ring data to determine
the 1990s was the warmest decade in the past thousand years.

The hockey-stick-shaped graph created by Dr. Mann to reflect the trend
was adopted by the UN's Intergovernmental Panel on Climate Change and
used by Canada to promote the Kyoto plan. But according to the Canadian
researchers, the program used to generate the graph had a computer error
that caused it to favour data that would lead to a hockey stick shape.

Mr. McIntyre said yesterday he fed random information into the program
to see what would happen. In 10,000 attempts using the meaningless data,
a hockey stick shape occurred 99% of the time.

"That would seem to be an unattractive statistical property," Mr.
McIntyre said.

In a response posted on the Internet, Dr. Mann characterizes Mr.
McIntyre's work as a "fishing expedition."

"Given a large enough number of analyzes, one can of course produce a
series that is arbitrarily close enough to just about any chosen
reference series," Dr. Mann said.

Andrew Weaver, a professor and Canadian Research Chair at the University
of Victoria, also dismissed the research.

"This is simply pure and unadulterated rubbish," he said."

For his part, Prof. Weaver described the researchers' focus on Dr.
Mann's work as "vindictive," noting numerous independent studies have
reflected the hockey stick trend.

"If you look in Intergovernmental Panel on Climate Change [reports],
there are four hockey sticks and they all show the same thing. And they
were all done with very different techniques, so why focus on just the
work of Dr. Mann?" Prof. Weaver said.

However, the allegations raised by Prof. McKitrick and Mr. McIntyre have
caused some to reconsider their reliance on the hockey stick graph. Rob
Van Dorland, who works with the Intergovernmental Panel on Climate
Change, told a European science magazine: "It is strange that the
climate reconstruction of Mann has passed both peer review rounds of the
IPCC without anyone ever really having checked it."

Mr. McIntyre identifies other problems with Dr. Mann's work. He claimed
the method used by Dr. Mann relied too heavily on the growth pattern of
one type of tree, the high altitude bristlecone pine. These trees have
experienced increased growth but that trend is not linked to temperature
increases, he said.

"There has been a growth pulse for the pines in the 20th century, so
their growth index does look like a hockey stick. But specialists are
puzzled about what caused that, because they've concluded it isn't
related to temperature," Mr. McIntyre said.

Copyright 2005 National Post. All Rights Reserved

---sbs--- ARTICLE 4 OF 4

Source: Marcel Crok (editor of Natuurwetenschap & Techniek, a Dutch
science magazine), "Breaking the Hockey Stick: The lone Gaspe cedar",
Financial Post (Canada), January 28, 2005, p. FP15

This is the second of our two-part series on the flawed science behind
the famous "Hockey Stick" chart of historic global temperatures that
forms the basis for claims that the world climate is in the midst of
unprecedented warming. In yesterday's first installment, Dutch science
journalist Marcel Crok outlined the story of two Canadians researchers,
Stephen McIntyre and Ross McKitrick, who found serious flaws in the
statistical methods used to construct the chart. The McIntyre/McKitrick
critique of the chart, created by U.S. scientist Michael Mann, will be
published in February by Geophysical Research Letters, the eminent
scientific publication. In today's report, Crok explores the rest of the
story of how the Canadian researchers uncovered the serious failures
that cast the whole chart into doubt.

- - -

There was yet another important discovery. McIntyre:"When we compared
data as used by Mann with original archived data, we found one and only
one example where the early values of a series had been extrapolated --
a cedar tree ring series from the Gaspe peninsula in Canada. The
extrapolation, from 1404 back to 1400, had the effect of allowing this
series to be included in the critical early 15th-century calculations.
When we did calculations both including and excluding the series, we
found that the difference was considerable. In some cases, the
temperature was as much as 0.2 degrees Celsius lower using the modified
Gaspe series as compared with the archived version.

"More strangely," said McIntyre, "the series appears twice in Mann's
data set, as an individual proxy, and in the North American network. But
it is only extrapolated in the first case, where its influence is very
strong." McIntyre and McKitrick went back to the source of the Gaspe
series and then to the archived data at the World Data Center for
Paleoclimatology."We found that although the Gaspe series begins in
1404, up until 1421, it is based on only one tree. Dendrochronologists
(tree ring researchers) generally do not use data based on one or two
trees. The original authors only used this series from 1600 onwards in
their own temperature reconstructions. This series should never have
been used in the 15th century, let alone counted twice and extrapolated."

McIntyre and McKitrick submitted a paper to Nature in January, 2004.
Mann and his colleagues were invited to respond. McIntyre: "They raised
an interesting point. They stated that the critical North American PC1
[a technical term: the first Principal Component (PC1) of a Principal
Component Analysis (PCA)] was not just based on the top-weighted Sheep
Mountain series, but that 14 other series were also highly weighted in
it. In late March, we sent in a second version of the article in which
we demonstrated that these 14 tree rings were all from highly
controversial bristlecone pine series, studied by Graybill and Idso in
1993, which showed an unusual growth spurt in the 20th century. Graybill
and Idso themselves attributed the growth spurt to higher concentrations
of CO2 in the air, because they were able to show that it was not caused
by increased temperatures. Oddly enough, in their 1999 article, Mann and
his colleagues had actually admitted the same thing: 'A number of tree
ring series at high altitudes in the western part of the United States
seem to show a prolonged growth spurt that is more pronounced than can
be explained with the measured increase in temperature in these
regions.' "

Now, a number of years later, Mann's defence includes the remark that
these same series form the "dominant" part of the Northern American PC1,
and accordingly, justifies their inordinate influence on the temperature
reconstruction of the entire Northern Hemisphere.

As the story unraveled, more intrigue came to the surface. McIntyre: "On
Mann's FTP site, the directory for the North American network contains a
subdirectory with the striking name BACKTO_1400-CENSORED. The folder
contains PCs that looked like the ones we produced, but it was not clear
how they had been calculated. We wondered if the folder had anything to
do with the bristlecone pine series: This was a bulls eye. We were able
to show that the 14 bristlecone pine series that effectively made up
Mann's PC1 (and six others) had been excluded from the PC calculations
in the censored folder. Without the bristlecones sites, there were no
hockey sticks for Mann's method to mine for, and the results came out
like ours. The calculations used in Mann's paper included the
controversial bristlecone pine series, which dominate the PC1 and impart
the characteristic hockey stick shape to the PC1 and thereafter to the
final temperature reconstruction. Mann and his colleagues never reported
the results obtained from excluding the bristlecone pines, which were
adverse to their claims."

McIntyre finds some irony in Mann's response. " After we published our
findings in Energy and Environment, Mann accused us of selectively
deleting North American proxy series. Now it appeared that he had
results that were exactly the same as ours, stuffed away in a folder
labeled CENSORED."

When McIntyre and McKitrick submitted the second version of their
article to Nature, they discussed the dubious role of the bristlecone
pine series and reported the CENSORED subdirectory." Nature then asked
us to shorten our article to a mere 800 words and we did. Months went by
and then we were told that they were now only willing to permit us 500
words and the content was too 'technical' to be dealt with in 500 words."

In January, 2005, an adapted version of McIntyre and McKitrick's paper
was accepted for publication by Geophysical Research Letters (GRL).
Judging by the reactions of the referees of GRL, which McIntyre made
available to us, the tide may be turning in the climatology field. One
referee stated: "S. McIntyre and R. McKitrick have written a remarkable
paper on a subject of great importance. What makes the paper significant
is that they show that one of the most important and widely known
results of climate analysis, the 'hockey stick' diagram of Mann et
al.,was based on a mistake in the application of a mathematical
technique known as principal component analysis (PCA)."

The same referee also writes: "McIntyre and McKitrick found a
non-standard normalization procedure in the Mann et al. analysis. Their
paper describes this procedure; it was an apparently innocent one of
normalization, but it had a major effect on their results. The Mann et
al. normalization tends to significantly increase the variance of data
sets that have the hockey-stick shape. In the Mann et al. data set, this
turned out to be bristlecone pines in the western United States. Thus
the hockey stick plot, rather than representing a true global average of
climate for the past thousand years, at best represented the behavior of
climate in the western U.S. during that period.This is an astonishing
result. I have looked carefully at the McIntyre and McKitrick analysis,
and I am convinced that their work is correct."

The referee ends with: "I urge you not to shy away from this paper
because of its potential controversy. The whole field of global warming
is currently suffering from the fact that it has become politicized.
Science really depends for its success on an open dialogue, with critics
on both sides being heard. McIntyre and McKitrick present a cogent
analysis of the global warming data. They do not conclude that global
warming is not a problem; they don't even conclude that the medieval
warm period really was there. All they do is correct the analysis of
prior workers, in a way that must ultimately help us in our
understanding of past climate, and predictions of future climate. That
makes this a very important paper. I strongly urge you to publish it."

Climate researchers can now no longer dismiss McIntyre and McKitrick's
efforts with the remark that they didn't publish in an authoritative
journal. Mann, Bradley and Hughes, meanwhile, continue to defend
themselves quite aggressively. One of the Nature referees noticed this
as well: "I am particularly unimpressed by the MBH style of 'shouting
louder and longer so they must be right.' "

Mann has obviously decided to defend his graph to the bitter end. Not
too long ago, he and his team launched a weblog, www.realclimate.org, in
which they strike back very aggressively. Mann's main criticism of
McIntyre and McKitrick's previous calculations is that they should have
expanded the list of North American PCs from two to five, so that the
bristlecone pines in the fourth PC (PC4) could be included.

Not surprisingly, McIntyre is unfazed by the criticism: "Mann claims
that his PC1 (essentially the bristlecone pine series) represents a
dominant trend in the North American network. Using his incorrect
standardization, the PC1 does account for 38% of the NOAMAER [North
American] network variance. However, in a correct calculation, the
bristlecones are demoted to the PC4 and only account for 8% of the
variation. Hardly a dominant trend, like Mann claims. His argument to
increase the number of PCs is simply a desperate move to salvage the
hockey stick. Look at this from a robustness point of view: Mann has
claimed in print that his result is so robust that even removing all his
tree ring data will not overturn it. Now all of a sudden, he insists
that a single PC4 based on the controversial bristlecone pine data plays
the deciding role in the temperature history of the entire Northern
Hemisphere."

When we put forward some of the criticism to Mann, Bradley and Hughes in
an e-mail, we received an elaborate response within the hour. Apart from
the stock arguments that McIntyre and McKitrick are not real scientists,
Mann rationalized the presence of the directory BACKTO_1400-CENSORED on
his FTP site: "After publication of the first hockeystick in 1998, we
ran a number of sensitivity tests to determine if we could come to a
reliable reconstruction without having to correct certain tree ring
series at high altitudes for non-climatological effects, like the
influence of CO2. We reported on this in the publication of 1999."

McIntyre is not satisfied: "In his second publication, Mann mentioned
problems with the bristlecone pines, but only with regards to the period
of 1000-1399 and not the 15th century that is in this file. More
importantly, if you know there are problems with the bristlecone pines,
the obvious test would be to eliminate them from the calculation and see
what the effect is. This is exactly what Mann did in the directory
BACKTO_1400-CENSORED. When he did not like the results, he did not
report them and proceeded to include the bristlecone pines in his final
analysis."

We asked Mann about the apparent inconsistency between the claimed
robustness and the evidence that the shape of his hockey stick relies
heavily on the bristlecone pines. Mann responds that he can reach the
same results even without doing a PCA, arguing that you could simply use
all 95 proxies individually in the calculations: "There is no clearer
proof that McIntyre and McKitrick claims are false."

"Mann is a clever debater," McIntyre points out. "That he can produce a
hockey stick with another method that also allows the bristlecone pines
to dominate is completely irrelevant. The bristlecone pine series are
still essential for this new result. When you do the calculation without
the bristlecone pines, the result does not resemble a hockey stick in
any way."

Mann further argued that he is not the only scientist to have found the
hockey stick graph: "Over a dozen other estimates based on proxy data
yield basically the same result." That argument is not new to McIntyre.

At this point, McIntyre has growing doubts about the other studies as
well. His initial impression is that they are also dubious. It is almost
certain, or so he states, that the other studies have not been checked
either. McIntyre: "Mann's archiving may be unsatisfactory, but other
researchers, including Crowley, Lowery, Briffa, Esper, etc, are even
worse. After 25 e-mails requesting data, Crowley advised me that he had
misplaced his original data and only had a filtered version of his data.
Briffa reported the use of 387 tree ring sites, but has not disclosed
the sites. Other researchers haven't archived their data or methods or
replied to requests."

"Mann speaks of independent studies, but they are not independent in any
usual sense. Most of the studies involve Mann, Jones, Briffa and/or
Bradley. Some data sets are used in nearly every study. Bristlecone pine
series look like they affect a number of other studies as well and I
plan to determine their exact impact. I'm also concerned about how the
proxies are selected. There is a distinct possibility that researchers
have either purposefully or subconsciously selected series with the
hockey stick shape. I'm planning to use simulations to test if the
common practice of selecting the so-called "most temperature sensitive"
series also yield hockey sticks from red noise."

McIntyre and McKitrick draw far reaching conclusions from their
research: "When the IPCC decides to base their policy on such studies,
triggering the spending of billions of dollars, there should be more
thorough checks. At some point, some one should have done an elementary
check on the principal component calculations. This never happened and
there is no excuse for this."

Rob van Dorland of the Royal Netherlands Meteorlogical Institute has
read the article that will appear in Geophysical Research Letters and is
convinced it will seriously damage the image of the IPCC. "For now, I
will consider it an isolated incident, but it is strange that the
climate reconstruction of Mann has passed both peer review rounds of the
IPCC without anyone ever really having checked it. I think this issue
will be on the agenda of the next IPCC meeting in Peking this May."

This brings climate research back to square one. McIntyre: "Our research
does not say that the earth's atmosphere is not getting warmer. But the
evidence from this famous study does not allow us to draw any
conclusions about its extent, relative to the past 1000 years, which
remains as much a mystery now as it was before Mann's article in 1998."

[Graphs] McIntyre and McKitrick, National Post; THE HOCKEY STICK
RECONSTRUCTED: Northern Hemisphere temperatures for the last 600 years:
Corrected temperature reconstruction by McIntyre and McKitrick, IPCC
temperature reconstruction by Mann: (See print copy for complete
chart/graph.); [Diagram]: The Northern Hemisphere.

Copyright 2005 National Post. All Rights Reserved

---sbs--- END OF THE 4 ARTICLES

Very truly,

Steve Schulin
http://www.nuclear.com

Message has been deleted

peroxisome

unread,
Jan 28, 2005, 9:53:03 PM1/28/05
to
Dear Lloyd
if you read the html for the link, you will see it is a reprint hosted
on Steve McIntyre's site.
Is that interesting enough for you ?
per

peroxisome

unread,
Jan 28, 2005, 10:16:52 PM1/28/05
to
It is interesting to read what Michael Mann (& Gavin Schmidt) writes at
the above blog.
Apparently referring to M&M, he says "All of their original claims have
now been fully discredited ...."
This is the same Michael Mann who wrote a corrigendum to MBH 98,
wherein he acknowledged M&M for pointing out to him that there were
errors in the description of the methodology in MBH 98. How can Michael
Mann write two such seemingly inconsistent statements ?

I think the emotional tenor in the realclimate piece speaks volumes
about Mann. M&M's work doesn't need to be "deeply flawed"; you don't
need "all" of M&M's claims to be "fully discredited"; you don't need to
talk about "false and specious claims". All you need to be able to do
is demonstrate one error in M&M's work.

The really bizarre thing is that everybody knows that Mann's reputation
is on the line in a big way. If MBH98 were to be shown to be flawed as
a direct result of M&M's criticism, and if MBH had to retract, it is
self-evident that Mann would have a difficult job maintaining his
credibility. Mann has considerable self-interest in killing off M&M's
claims, and everyone can see it in the emotional tone of his writing.
Mann has now publically disparaged the peer-review process at GRL; I am
guessing the anonymous referees who conducted the peer-review, and the
relevant editor of the journal, may not be impressed by this
implications of this statement.

yours
per

James Annan

unread,
Jan 28, 2005, 10:19:48 PM1/28/05
to
peroxisome wrote:


> Isn't there a feeling of eating crow,
> now that M&M have published in a bona fide environmental journal.

Yes. Although I don't know about the significance of the results for
climate science in general (there appear to be serious problems with
M&M's approach, and Mann has given what appears to be a reasonable
defence of the results) it is certainly a bit of an embarassment for
those involved - or should be.

James
--
If I have seen further than others, it is
by treading on the toes of giants.
http://www.ne.jp/asahi/julesandjames/home/

James Annan

unread,
Jan 28, 2005, 10:35:10 PM1/28/05
to
peroxisome wrote:


> I think the emotional tenor in the realclimate piece speaks volumes
> about Mann.

I agree and I think it devalues realclimate. I didn't think it was
supposed to be a hobby-horse for personal spats.

peroxisome

unread,
Jan 28, 2005, 10:40:07 PM1/28/05
to
Hi there W
can I take your advice as a learned Climate Modeller and Environmental
Scientist ?

M&M have now published a paper in GRL, a peer-reviewed journal in the
scientific literature. What is your take on this paper ? Is it valid,
or do you subscribe to the same view of the paper and peer-review
process as Mann has published on the realclimate blog ?
yours
per

Joshua Halpern

unread,
Jan 28, 2005, 11:49:50 PM1/28/05
to
James Annan wrote:
> peroxisome wrote:
>
>
>> Isn't there a feeling of eating crow,
>> now that M&M have published in a bona fide environmental journal.
>
Nah: http://tinyurl.com/539d7

Thomas Palm

unread,
Jan 29, 2005, 3:16:47 AM1/29/05
to
"peroxisome" <perox...@ntlworld.com> wrote in
news:1106968612.2...@z14g2000cwz.googlegroups.com:

> It is interesting to read what Michael Mann (& Gavin Schmidt) writes at
> the above blog.
> Apparently referring to M&M, he says "All of their original claims have
> now been fully discredited ...."
> This is the same Michael Mann who wrote a corrigendum to MBH 98,
> wherein he acknowledged M&M for pointing out to him that there were
> errors in the description of the methodology in MBH 98. How can Michael
> Mann write two such seemingly inconsistent statements ?

I don't think they are inconsistent. Go back and check what M&M claimed
in their first article, and it was all about how M&M had gotten the wrong
result, used the wrong methods etc. I'm not sure they ever claimed
something as trivial as that MBH had made an error in specifying what
data series they had used.



> I think the emotional tenor in the realclimate piece speaks volumes
> about Mann. M&M's work doesn't need to be "deeply flawed"; you don't
> need "all" of M&M's claims to be "fully discredited"; you don't need to
> talk about "false and specious claims". All you need to be able to do
> is demonstrate one error in M&M's work.

Well, no, you need to demonstrate an error large enough to significantly
change the result. You rarely find papers that contains no errors. So far
M&M are the ones who have made the known, serious mistakes.

Given how long this feud has been going on it would be a good idea if
some climate researchers totally independend from MBH and M&M took the
time to try to replicate the results. Usually scientists don't bother
since they are busy trying to get better results instead, but this has
become so infected it may be necessary to make an exception.

> claims, and everyone can see it in the emotional tone of his writing.
> Mann has now publically disparaged the peer-review process at GRL; I am
> guessing the anonymous referees who conducted the peer-review, and the
> relevant editor of the journal, may not be impressed by this
> implications of this statement.

As far as disparaging goes his statement "McIntyre and McKitrick (2005),

in a paper they have managed to slip through the imperfect peer-review

filter of GRL" is fairly mild, abaout as mild as it can be if he
considers the paper junk. It is no secret that bad papers slip through
occasionally in all journals. If you want real disparaging you'll have to
go to the contrarians, such as this pearl by Roy Spencer of MSU fame:

"I will admit to being uneasy about airing scientific dirty laundry in an
op-ed. But as long as these popular science journals insist on putting
news value ahead of science, then I have little choice. The damage has
already been done. A paper claiming to falsify our satellite temperature
record has been published in the "peer reviewed" literature, and the
resulting news reports will never be taken back. This is one reason
increasing numbers of scientists regard Science and Nature as "gray"
scientific literature."
http://www.techcentralstation.com/050504H.html

peroxisome

unread,
Jan 29, 2005, 6:57:41 AM1/29/05
to
>Go back and check what ­M&M claimed
>in their first article, and it was all about how M&M had got­ten the
wrong
>result, used the wrong methods etc. I'm not sure they ever c­laimed
>something as trivial as that MBH had made an error in specif­ying

what
>data series they had used.
the original M&M paper is freely accessible on the web. Your
understanding of that paper is in error; M&M specifically claim that
there are data errors in the original MBH98- indeed, this is a major
point of their paper, and this is why MBH were obliged to acknowledge
them in their correction.
yours
per

peroxisome

unread,
Jan 29, 2005, 6:53:25 AM1/29/05
to
your link goes to :
http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JAPIAU000096000006003095000001&idtype=cvips&gifs=yes
Water bath calorimetric study of excess heat generation in "resonant
transfer" plasmas
a bit cryptic perhaps ?

David Ball

unread,
Jan 29, 2005, 9:12:20 AM1/29/05
to
On 28 Jan 2005 18:51:09 -0800, "peroxisome" <perox...@ntlworld.com>
wrote:

>Dear W
>you seem to be correct.
>you may also recall that this question has been asked and answered
>before on this forum.
>And while we are asking stupid questions, are you either McIntyre or
>McKitrick ?
>per

I asked it last time and you never responded, but then my
newsreader has the annoying habit of dropping the odd post. Why don't
you repost it again? It's awfully interesting that you take no part in
any discussions here. I even went to the archives and plugged in your
e-mail address into the Google archives. I found 264 posts made by you
dating back to last year. Aside from a single post on the thread
"Toxicity of 4 phenylcyclohexane?", every post was on some aspect of
M&M's work. Rather an odd coincidence, don't you think?

David Ball

unread,
Jan 29, 2005, 9:14:50 AM1/29/05
to
On Fri, 28 Jan 2005 21:14:42 -0500, Steve Schulin
<steve....@nuclear.com> wrote:

>In article <1106856346.6...@f14g2000cwb.googlegroups.com>,
> "peroxisome" <perox...@ntlworld.com> wrote:
>
>> A new paper in Energy and Environment
>> http://www.multi-science.co.uk/mcintyre-mckitrick.pdf
>> A new paper in Geophysical Research Letters
>> http://www.climate2003.com/pdfs/2004GL012750.pdf
>>
>> So, apparently in contradiction to much of the verbal abuse spouted
>> about these authors, M&M's work is sufficiently good to pass
>> peer-review in Geophysical Research Letters. Does that make them bona
>> fide scientists ?
>>
>> Couldn't resist the spectacle of Michael Mann making some pretty
>> undignified commentary about M&M; and he imagines that no-one will
>> notice his own vested interest in making these comments.
>> http://www.realclimate.org/index.php?p=111#more-111
>>
>> per
>>
>
>The last couple of days has seen extensive coverage of the "Hockey
>Stick" in Canada's National Post and its Financial Post. Here are four
>articles, including one from front page yesterday:
>

Still getting your science from the funny papers, I see.

peroxisome

unread,
Jan 29, 2005, 9:24:40 AM1/29/05
to
well, I can tell you you are missing a lot of information.
I am not, and not "affiliated to", M or M
Your observation is not a coincidence. As I have explained, I find the
response to M&M's work profoundly unscientific, and the issue
consequently of interest.
yours
per

Eric Swanson

unread,
Jan 29, 2005, 11:11:53 AM1/29/05
to
In article <1106970006.9...@f14g2000cwb.googlegroups.com>, perox...@ntlworld.com says...

Wrong.

The paper has not been published as yet (29 Jan), according to the AGU web
site. McKitrick claims that the paper has been ACCEPTED FOR PUBLICATION as
2004GL012750. I suggest one should wait until the paper has actually reached
the official GRL web page before calling it "published".

Of course, the denialists propaganda machine was all over it, just in time for
Davos...

--
Eric Swanson --- E-mail address: e_swanson(at)skybest.com :-)
--------------------------------------------------------------

peroxisome

unread,
Jan 29, 2005, 11:33:46 AM1/29/05
to
Dear Thomas, you wrote:"So far M&M are the ones who have made the
known, serious mistakes. "
May I direct you towards
http://holocene.evsc.virginia.edu/shared/articles/MBH98-corrigendum04.pdf
? It is common ground that this corrigendum corrects numerous and
significant errors in MBH 98.

You describe the link at techcentral as a "pearl"
(http://www.techcentralstation.com/050504H.html). Strange, but I look
at the article, and come to exactly the opposite conclusion to you. In
the paragraph you cite, the author doesn't call the other guys names,
there is no "misleading", "false", "multiple errors", etc; indeed in
the whole article, the author complains that the Nature paper has made
a methodological "mistake", and spends four paragraphs and a figure
explaining why this is a mistake. That looks pretty reasonable to me.

By contrast, at http://www.realclimate.org/index.php?p=111 , I count 17
phrases as sneering in the first two paragaphs, and then I gave up. If
the authors had a clear case to make to justify their sneers, they
failed to make it clear to me. However, I am prepared to accept that
you are happier with Mann's style of writing.
yours
per

peroxisome

unread,
Jan 29, 2005, 11:37:17 AM1/29/05
to
Dear Eric
thanks for your accurate contribution. Perhaps I can ask you a question
?

M&M have now had a paper ACCEPTED FOR­ PUBLICATION in GRL, a
peer-reviewed jour­nal in the
scientific literature. What is your take on this paper, and will it
change when it is published on the GRL web site ? Is­ it valid,
or do you subscribe to the same view of the paper and peer-­review

peroxisome

unread,
Jan 29, 2005, 11:42:17 AM1/29/05
to
Dear David
you will notice that I have now responded to your question. Will you
now respond to my question ?
Just in case you can't remember:
So david, I can't remember but I would be fairly sure that y­ou were

one
of the guys who made the case that M&M's work was not to be ­trusted
because (a) it wasn't in a "real" peer-reviewed journal (b) ­M&M
aren't
"real" environmental scientists. Isn't there a feeling of ea­ting
crow,
now that M&M have published in a bona fide environmental jou­rnal.

And what is even better, their peer-reviewed comments about ­MBH98 !

Since it is in the peer-reviewed literature, it must be true­, no ? Or

are you in the camp that is now backing quickly away from MB­H98 ?
yours
per

Thomas Palm

unread,
Jan 29, 2005, 12:16:02 PM1/29/05
to
"peroxisome" <perox...@ntlworld.com> wrote in
news:1107016426.1...@z14g2000cwz.googlegroups.com:

> Dear Thomas, you wrote:"So far M&M are the ones who have made the
> known, serious mistakes. "
> May I direct you towards
> http://holocene.evsc.virginia.edu/shared/articles/MBH98-corrigendum04.pdf
> ? It is common ground that this corrigendum corrects numerous and
> significant errors in MBH 98.

"None of these errors affect our previously published results." Errors that
don't affect the result are not what I would call serious.

> You describe the link at techcentral as a "pearl"
> (http://www.techcentralstation.com/050504H.html). Strange, but I look
> at the article, and come to exactly the opposite conclusion to you. In
> the paragraph you cite, the author doesn't call the other guys names,
> there is no "misleading", "false", "multiple errors", etc; indeed in
> the whole article, the author complains that the Nature paper has made
> a methodological "mistake", and spends four paragraphs and a figure
> explaining why this is a mistake. That looks pretty reasonable to me.

Does it really look reasonable to you to call the two scientific journals
that have the highest impact factors "gray literature"?

peroxisome

unread,
Jan 29, 2005, 12:38:56 PM1/29/05
to
> Dear Thomas, you wrote:"So far M&M are the ones who have m­ade the

> known, serious mistakes. "
> May I direct you towards
>
http://holocene.evsc.virginia.edu/shared/articles/MBH98-corrigendum04...

> ? It is common ground that this corrigendum corrects numer­ous and


> significant errors in MBH 98.


"None of these errors affect our previously published result­s."


Errors that
don't affect the result are not what I would call serious.

Dear Thomas
perhaps you misunderstand. Nature's policy is that ONLY significant
corrigenda are published. MBH admit in their corrigenda to not using
data series they said they did, using data series they didn't mention,
and numerous other issues. These are all serious defects in their
description of MBH 98; which is why there was a corrigendum.
Their case is that their error was simply in the description of what
they did; an issue which would obviously not change the underlying
result. It is a serious error if you are trying to replicate the
findings of MBH98, and Nature policy is that it was a significant
error. However, I accept that you may think it is entirely acceptable
to publish a misleading account of your methods which is replete with
errors.

>"Does it really look reasonable to you to call the two scient­ific


journals that have the highest impact factors "gray literature"? "

They don't have the highest impact factor; though I appreciate that is
only a detail for you. I am quite clear that there are very good papers
in science and nature; but then, there do seem to be a surprising
number of papers in these journals which are subsequently shown to be
non-reproducible, or which are published for political reasons. The
original super-additivity of endocrine disruptors paper, the high
toxicity of ecstasy to primates paper were both withdrawn. The recent
science paper on dioxin/ pops in fish was a splendid example of a paper
which contained no novel findings, but gave lots of newspaper headlines
about non-existent health risks.
yours
per

Eric Swanson

unread,
Jan 29, 2005, 1:25:48 PM1/29/05
to
In article <1107016637....@f14g2000cwb.googlegroups.com>,
perox...@ntlworld.com says...

>
>Dear Eric
>thanks for your accurate contribution. Perhaps I can ask you a question
>?
>
>M&M have now had a paper ACCEPTED FOR=AD PUBLICATION in GRL, a
>peer-reviewed jour=ADnal in the

>scientific literature. What is your take on this paper, and will it
>change when it is published on the GRL web site ? Is=AD it valid,
>or do you subscribe to the same view of the paper and peer-=ADreview
>process as Mann has published on the realclimate blog ?=20

Sorry to say that M&M's work is not an area that I have great knowledge of.
In any event, I have not studied their GRL paper, so I have no comment.

Vendicar Decarian

unread,
Jan 29, 2005, 6:20:44 PM1/29/05
to

"Steve Schulin" <steve....@nuclear.com> wrote in message
news:steve.schulin-70D...@comcast.dca.giganews.com...

> The last couple of days has seen extensive coverage of the "Hockey
> Stick" in Canada's National Post and its Financial Post. Here are four
> articles, including one from front page yesterday:

Ah yes. Canada's versions of the National Enquirer and the Washington Post.

One wonders how long these newspapers can continue to bleed red, and what
conservative funding is keeping them operating.


Steve Schulin

unread,
Jan 29, 2005, 6:17:39 PM1/29/05
to
In article <5i6nv01h5gl9oe3bc...@4ax.com>,
David Ball <wra...@mb.sympatico.ca> wrote:

> Still getting your science from the funny papers, I see.

I recall that more of your countrymen claim to support Kyoto Protocol
than claim to know anything about it. I'm heartened at the prospect of
how this may change. There's much in these National Post and Financial
Post articles in recent days, which you disparage, which is of interest
to me, and I suspect, to others.

w...@bas.ac.uk

unread,
Jan 29, 2005, 6:25:23 PM1/29/05
to
peroxisome <perox...@ntlworld.com> wrote:
>Dear Thomas, you wrote:"So far M&M are the ones who have made the
>known, serious mistakes. "
>May I direct you towards
>http://holocene.evsc.virginia.edu/shared/articles/MBH98-corrigendum04.pdf
>? It is common ground that this corrigendum corrects numerous and
>significant errors in MBH 98.

This is silly. Its common ground that the corrigendum makes *absolutely
no difference to the results* and only concerns description/documentation.

-W.

--
William M Connolley | w...@bas.ac.uk | http://www.antarctica.ac.uk/met/wmc/
Climate Modeller, British Antarctic Survey | Disclaimer: I speak for myself
I'm a .signature virus! copy me into your .signature file & help me spread!

w...@bas.ac.uk

unread,
Jan 29, 2005, 6:30:57 PM1/29/05
to
peroxisome <perox...@ntlworld.com> wrote:
>can I take your advice as a learned Climate Modeller and Environmental
>Scientist ?

Yes indeed. Advice is what you need.

>M&M have now published a paper in GRL, a peer-reviewed journal in the
>scientific literature. What is your take on this paper ? Is it valid,
>or do you subscribe to the same view of the paper and peer-review
>process as Mann has published on the realclimate blog ?

Well, they haven't yet, though its scheduled for publication in Feb,
according to M&M. My take is that GRL have published a bit of septic
stuff recently (there was a pair of Singer ones that shouldn't have got
through in the form they did). Not having read MM05 yet, I don't know if
it falls into that class. As for peer review in general, I recommend:

http://www.realclimate.org/index.php?p=109

for a nice discussion.

Hans Erren

unread,
Jan 29, 2005, 7:11:53 PM1/29/05
to
Thomas Palm wrote:
> http://www.realclimate.org/index.php?p=111

> "MM however, continue to promote false and specious claims. McIntyre and

> McKitrick (2005), in a paper they have managed to slip through the

> imperfect peer-review filter of GRL, now simply recycle the very same false
> claims made by them previously in their comment on MBH98 that was rejected
> by Nature."

Here is another paper that "managed to slip through the imperfect
peer-review filter of GRL":

Mann, M., R. Bradley, and M.K. Hughes. 1999. Northern hemisphere
temperatures during the past millennium: Inferences, uncertainties,
and limitations. Geophysical Research Letters, Vol. 26, No. 6, pp.
759-762

peroxisome

unread,
Jan 29, 2005, 7:35:58 PM1/29/05
to
Dear W
>It is common ground that this corrigendum corrects numero­us and

>significant errors in MBH 98.
> >This is silly.
Let me quote to you what the corrigendum says.
"the listing of the 'proxy' data set in the Supplementary
Information published with this Article contained several errors."
So when I say that the corrigendum corrects significant errors, am I
not simply repeating what the authors have written ? Nature will only
allow corrigenda which it ajudges to be significant. M&M believed that
MBH98 was in error; MBH have stated that the original paper had errors.
It is common ground. Why is this silly, W ?

> > Its common ground that the corrigendum makes ­*absolutely
> > no difference to the results*

MBH assert that their corrigendum makes no difference to the results.
However, I am not aware the M&M have accepted this; indeed, I believe
that they objected in writing to this phrase. I am struggling to
discern how you can establish that this statement is "common ground",
unless you mean that the statement is common ground to Mann, Bradley
and Hughes alone.

Even if you accept that MBH got their description of the methods wrong
by "merely" omitting data sets they used, claiming to use data sets
they didn't, and publishing a methods section which is wholly
inadequate, if not actually positively inconsistent, with their new
methods, the idea that publishing a completely inadequate and
misleading methods section is trivial beggars belief. Do you believe
that it is acceptable to publish a paper with a misleading and
inaccurate methods section, W ?
yours
per

peroxisome

unread,
Jan 29, 2005, 8:09:39 PM1/29/05
to
Dear W
>Not having read MM05 yet, I d­on't know if

>it falls into that class.
let me commend you on your circumspection. Do you want a copy of this
manuscript ? I provided a link at the top of this topic, and I am
assuming you have Acrobat reader installed ?

I know you have strongly held views on this subject, so I would be very
interested to hear what you think when you examine the evidence. When
could I expect your view ?

>As for peer review in general, I r­ecommend:

Thank you for recommending an article by Michael Mann on scientific
standards. I have read alleged records of email correspondence between
Mann, and MM, as posted on McKitrick's web site. It would appear that
when Mann was confronted with problems about a seminal paper he
published in Nature, he was distinctly unhelpful. Yet after M&M03, it
must have been obvious to MBH that there were defects in their paper in
Nature. It appears that Mann addressed his scientific responsibility
for full and honest disclosure ony after a direct Materials complaint
to Nature.

I am just waiting for you to recommend me an article written by Mann on
"full and honest disclosure in scientific publishing"; presumably right
after the article on "respect for people with competing hypotheses".
sheesh
per

peroxisome

unread,
Jan 29, 2005, 8:43:19 PM1/29/05
to
> A new paper in Geophysical Research Letters
> http://www.climate2003.com/pdfs/2004GL012750.pdf
turns out that one of the GRL referees comments are online at:
http://www.uoguelph.ca/~rmckitri/research/Climate_L.pdf
"S.McIntyre

and R. McKitrick have written a remarkable paper on a
subject of great importance.What makes the paper significant is

that they show that one of the most important and widely
known results of climate analysis, the "hockey stick" diagram of
Mann et al.,was based on a mistake in the application of a mathematical
technique known as principal component analysis
(PCA)."

wonder what invective this is going to bring down on the referee from
realclimate ?
yours
per

Joshua Halpern

unread,
Jan 29, 2005, 8:49:11 PM1/29/05
to
Read it. Follow up on the authors.

josh halpern

peroxisome

unread,
Jan 29, 2005, 9:08:52 PM1/29/05
to
Dear Josh
re: Journal of Applied Physics -- September 15, 2004 -- Volume 96,
Issue 6, pp. 3095-3102

> Read it. Follow up on the authors.
i don't have access to J App Phys. The authors are from Uni of New
Mexico, and Black Light power.
I am struggling to find the link here. In response to :

>> Isn't there a feeling of eating crow,
>> now that M&M have published in a bona fide environmental ­journal.
you said "Nah" and gave this link.
I feel that David Ball did hand out a lot of abuse that M&M weren't fit
to comment, on account of their background. Now they have published in
the peer-reviewed scientific literature, I think DB should be eating
crow.
I just don't see how your link applies.
apologies
per

James Annan

unread,
Jan 30, 2005, 12:23:55 AM1/30/05
to
peroxisome wrote:

>>A new paper in Geophysical Research Letters
>>http://www.climate2003.com/pdfs/2004GL012750.pdf
>
> turns out that one of the GRL referees comments are online at:
> http://www.uoguelph.ca/~rmckitri/research/Climate_L.pdf
> "S.McIntyre
> and R. McKitrick have written a remarkable paper on a
> subject of great importance.What makes the paper significant is
> that they show that one of the most important and widely
> known results of climate analysis, the "hockey stick" diagram of
> Mann et al.,was based on a mistake in the application of a mathematical
> technique known as principal component analysis
> (PCA)."


I don't believe they have shown that at all. While M&M have shown that
the method was unusual and asked some valid questions about its
suitability, Mann's response on the particular point above (ie, the
final result of the reconstruction) seems quite convincing to me. M&M
(and their fans) seem to equate the first principle component with the
eventual reconstruction, which isn't correct at all.

James
--
If I have seen further than others, it is
by treading on the toes of giants.
http://www.ne.jp/asahi/julesandjames/home/

Joshua Halpern

unread,
Jan 30, 2005, 1:55:56 AM1/30/05
to
That's enough to find what I am talking about

josh halpern

David Ball

unread,
Jan 30, 2005, 3:02:04 AM1/30/05
to
On 29 Jan 2005 08:42:17 -0800, "peroxisome" <perox...@ntlworld.com>
wrote:

LOL. You just don't get it. M&M's work is flawed from the
get-go and numerous studies have shown it to be. The fact that it
managed to make it through a misstep in the peer-review process
doesn't validate their efforts. M&M's work is still not to be trusted.

Thomas Palm

unread,
Jan 30, 2005, 5:19:05 AM1/30/05
to
"peroxisome" <perox...@ntlworld.com> wrote in
news:1107049399.6...@c13g2000cwb.googlegroups.com:

>> A new paper in Geophysical Research Letters
>> http://www.climate2003.com/pdfs/2004GL012750.pdf
> turns out that one of the GRL referees comments are online at:
> http://www.uoguelph.ca/~rmckitri/research/Climate_L.pdf
> "S.McIntyre
> and R. McKitrick have written a remarkable paper on a
> subject of great importance.What makes the paper significant is
> that they show that one of the most important and widely
> known results of climate analysis, the "hockey stick" diagram of
> Mann et al.,was based on a mistake in the application of a mathematical
> technique known as principal component analysis
> (PCA)."

I thought referee comments were supposed to remain confidential, and I have
the distinct memory the M&M were forced to remove some from Nature from
their website earlier. I wonder if GRL is going to be any happier that
McIntyre sends referee comments around like that.

peroxisome

unread,
Jan 30, 2005, 8:45:51 AM1/30/05
to
>I thought referee comments were supposed to remain confidenti­al
Referees frequently have the opportunity of providing advice to the
editor which may well be confidential; but it is also standard practice
to provide the authors with comments from the referee which are written
to be publically available.
yours
per

Roald B. Larsen

unread,
Jan 30, 2005, 8:31:11 AM1/30/05
to

"Steve Schulin" <steve....@nuclear.com> skrev i melding

news:steve.schulin-70D...@comcast.dca.giganews.com...
>>
> The last couple of days has seen extensive coverage of the "Hockey
> Stick" in Canada's National Post and its Financial Post. Here are four
> articles, including one from front page yesterday:
>
> ---sbs--- ARTICLE 1 OF 4
>
> Source: Marcel Crok (editor of Natuurwetenschap & Techniek, a Dutch
> science magazine), "Breaking the hockey stick: The famous graph that
> supposedly shows that recent temperatures are the highest in a thousand
> years has now been shown by careful analysis to have been based on
> faulty data", Financial Post (Canada), January 27, 2005, p. FP11

I don't think so:

www.natutech.nl/nieuwsDetailP.lasso?ID=2564

Onze vragen aan Mann

Dear dr Mann, dr Bradley and dr Hughes,

I am working on a long (10 page) cover story on the Hockey
Stick for Natuurwetenschap & Techniek, a Dutch monthly science magazine
which is comparable with Scientific American.

I have made a detailed analysis of MBH98 and also of the work
of McIntyre & McKitrick (MM) and Von Storch & Zorita. I also studied your latest
comment on MM04 on the weblog www.realclimate.org (dd 4 December)

In my opinion there are some issues still open on which I
would like to hear your comment. This could be done by email, but I
would prefer to call one of you and discuss the topic by phone.

Here are the issues:

1) How do you explain the existence of the directory
BACKTO_1400-CENSORED on Mann's ftp-server? MM show that it contains
the results of the calculation of the NOAMER PC's without using the bristlecone
pine series, giving a higher NH temperature in the 15th century.

2) There is a severe debate between you and MM about the skill
of the calculation. You claim a high RE-statistic. MM show that their simulated
hockey sticks also give a high RE-statistic but a very low R^2 statistic. In
MBH98 you didn't calculate the R^2 statistic, but in Mann and Jones (2003) you
did. I asked Eduardo Zorita questions about this and he said he would calculate
both. Why didn't you calculate the R^2 in MBH98?

3) On the weblog www.realclimate.org you state that MM should
use 5 PC's in the NOAMER-network if they use conventional PCA. Especially the
PC4 is important while it accounts for the bristlecone pine series. This means
that the overall result in MBH98 depends on a single PC4. This is in contrary
with the claimed robustness of the MBH98 method. Do you agree now that the
robustness of MBH98 is lower than originally claimed?

I am looking forward to discuss these issues with one of you.
If for time or other reasons you're not able to respond to this email before
Friday, January 7, could you please give me a short reply.

Yours sincerely,

Marcel Crok

N&T 26/01/2005

--------------------------------------------------------------------
© 2005 - Natuurwetenschap & Techniek

***


www.natutech.nl/nieuwsDetailP.lasso?ID=2565

Het antwoord van Mann

Dear Mr. Crok,

Below are some responses to your questions. Unfortunately, I
will be unable to reply in any more detail for more than another week due to
surgery I am having (and post-surgery recovery), so you should direct
further inquiries to my colleagues Bradley and Hughes, as well as the
other scientists I mention below.

I hope you are not fooled by any of the "myths" about the
hockey stick that are perpetuated by contrarians, right-wing think tanks, and
fossil fuel industry disinformation. These myths are each dispelled here.

http://www.realclimate.org/index.php?p=11

Of particular relevant here is "myth #1" (that the "hockey
stick" depends only on Mann et al--more than a dozen other estimates
from proxy data and model simulations get essentially the same result
(i.e., the results agree within the estimated uncertainties). See:

http://www.realclimate.org/index.php?p=7#figures

I must begin by emphasizing that McIntyre and McKitrick are
not taken seriously in the scientific community. Neither are scientists, and one
(McKitrick) is prone to publishing entirely invalid results apparently without
apology (see below). "New Scientist" considered running an article (by David
Paterson) on the MM claims. The editor decided not to run an article, concluding
that their claims were suspicious and spurious after interviews with numerous
experts and after it was revealed that they had suspiciously close ties with the
fossil fuel/energy industry. See e.g.:
http://www.environmentaldefense.org/article.cfm?contentid=3804&CFID=21084385&CFTOKEN=29888831
You can see what USA Today science report Dan Vergano had to
say about MM here:
http://www.usatoday.com/weather/climate/2003-11-18-warming-debate_x.htm


I therefore hope that you will treat their claims with
appropriate suspicion, and I that hope you will solicit comments from
paleoclimate experts such as Phil Jones, Keith Briffa, Jonathan Overpeck,
and Tom Crowley, and not rely upon comments from individuals who have
little expertise in this area.

You should also discuss with Caspar Ammann and Gene Wahl of
NCAR (amm...@ucar.edu, wa...@alfred.edu). They have independently
discredited (paper in press, I believe) McIntyre and McKitrick. They
independently reproduce the results of MBH98, and reproduce the skill in
these results. They also show that the results of McIntyre and McKitrick
can only be reproduced through a censoring of the dataset.

In summary. please keep in mind that McIntyre and Mckitrick
(1) never published their results in a peer-reviewed scientific journal ("Energy
and Environment" is not considered a scientific journal, but a "social science"
journal), (2) The claims, which you repeat below, were REJECTED by Nature
because the reviewers and editors did not believe they had made their case,
and (3) There are now 2 peer-reviewed articles discrediting MM, one that
is in press:

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 Methodology,
http://www.realclimate.org/RuthetalJClim2004.pdf Predictor Network,
Target Season and Target Domain, Journal of Climate, in press (2005).

and another by Ammann and Wahl (whom you should contact
for more information, as mentioned above).

Replies to your specific inquiries provided below:

Best regards,

Mike Mann

[[At 10:22 AM 1/4/2005, Marcel Crok wrote:


Dear dr Mann, dr Bradley and dr Hughes,

I am working on a long (10 page) cover story on the Hockey
Stick for Natuurwetenschap & Techniek, a Dutch monthly science magazine
which is comparable with Scientific American.

I have made a detailed analysis of MBH98 and also of the work
of McIntyre & McKitrick (MM) and Von Storch & Zorita. I also studied your latest
comment on MM04 on the weblog http://www.realclimate.org/ (dd 4 December) ]]


You should be aware that a comment is in press in "Science"
casting significant doubt on the claims of Von Storch and Zorita, and another
paper, in review, suggests that their conclusions are incorrect. A 3rd paper,
by the Danish Meteorological Institute (DMI) group using the same model as von
Storch, cannot reproduce the von Stroch results (they find much less variability
than von Storch), suggesting that there were some serious problems with the
von Storch simulation as well as with their analysis of the simulation results.
I would suggest that you get in touch with these individuals (e.g. Keith Briffa:
k.br...@uea.ac.uk or Martin Stendel: m...@dmi.dk) for a more balanced
view of the Von Storch claims.


[[In my opinion there are some issues still open on which I
would like to hear your comment. This could be done by email, but I would
prefer to call one of you and discuss the topic by phone.

Here are the issues:
1) How do you explain the existence of the directory
BACKTO_1400-CENSORED on Mann's ftp-server? MM show that it contains
the results of the calculation of the NOAMER PC's without using the bristlecone
pine series, giving a higher NH temperature in the 15th century. ]]


It is sad that McIntyre and McKitrick have been reduced to
scouring our website for things like this, to take out of context, and make
false and misleading assertions. We performed a set of sensitivity tests to
determine if a skillful reconstruction was available without correcting certain
high-elevation tree-ring chronologies for sensitivity to possible non-climatic
(e.g. co2-fertilization) effects. These calculations were performed as part of
these analyses, after MBH98. This is all discussed quite clearly in our
follow-up paper to MBH98 published in the journal GRL in 1999:

Mann, M.E., Bradley, R.S. and Hughes, M.K., Northern
Hemisphere Temperatures During the Past Millennium: Inferences,
Uncertainties, and Limitations, Geophysical Research Letters,
26, 759-762, 1999:
ftp://holocene.evsc.virginia.edu/pub/mann/MBH1999.pdf


This claim by MM is just another in a series of disingenuous
(off the record: plainly dishonest) allegations by them about our work.


[[2) There is a severe debate between you and MM about the
skill of the calculation. You claim a high RE-statistic. MM show that their
simulated hockey sticks also give a high RE-statistic but a very low R^2
statistic. ]]


We showed in our reply to the REJECT MM comment to Nature,
that they incorrectly calculated all of their verification statistics, because
they didn't account for the changing spatial sampling of the Northern Hemisphere
temperature record back in time. See the attached supplementary information
("supplementary3.pdf"--read page 2) that was provided to the reviewers of the
rejected comment by McIntyre and McKitrick. Keep in mind that the reviewers of
their Nature comment, who had the expertise and full available material to judge
whether or not MM's claims were plausible, decided that they were not.

Our reconstruction passes both RE and R^2 verification
statistics if calculated correctly. Wahl and Ammann (in press) reproduce our
RE results (which are twice as high as those estimated by MM), and cannot
reproduce MM's results. There is little, if anything correct, in what MM have
published or claimed. Again, none of their claims have passed a legitimate
scientific peer review process!

See also Rutherford et al (in press--see above) for an
extensive discussion of cross-validation, and the relative merits of different
metrics (RE vs CE vs r2). It is well known to any scientists in meteorology
or climatology that RE is the preferred metric for skill validation because it
accounts for changes in mean and variance prior to the calibration interval
(which R^2 does not!). The preferred use of RE dates back to the famous
paper by Lorenz in evaluated skill in meteorological forecasts.

It must be stated that McKitrick has been shown to be prone to
making major errors in his published work. You should refer to the
discussions here:
http://www.realclimate.org/index.php?p=41

and here:
http://cgi.cse.unsw.edu.au/~lambert/cgi-bin/blog/2004/08#mckitrick6

particularly interesting, in the context of this discussion,
is his failure in an independent context (the Michaels and McKitrick paper
discussed in the first link) to understand the issue of cross-validation! That
is, in both the McIntyre and McKitrick '03 paper, and the Michaels and McKitrick
'05 paper, the authors failed to even understand the importance of performing
cross-validation! Such papers could never be published in a respected
scientific journal.


[[In MBH98 you didn't calculate the R^2 statistic, but in Mann
and Jones (2003) you did. I asked Eduardo Zorita questions about this
and he said he would calculate both. Why didn't you calculate the
R^2 in MBH98? ]]


Repeating what I said above, see Rutherford et al (in
press--see above) for an extensive discussion of cross-validation, and the
relative merits of different metrics (RE vs CE vs R^2). It is well known to any
scientists in meteorology or climatology that RE is the preferred metric for
skill validation because it accounts for changes in mean and variance
prior to the calibration interval (which R^2 does not!). The preferred
use of RE dates back to the famous paper by Lorenz in evaluated skill
in meteorological forecasts.


3) On the weblog http://www.realclimate.org/ you state that MM
should use 5 PC's in the NOAMER-network if they use conventional PCA.
Especially the PC4 is important while it accounts for the bristlecone pine
series. This means that the overall result in MBH98 depends on a single
PC4. This is in contrary with the claimed robustness of the MBH98 method.
Do you agree now that the robustness of MBH98 is lower than originally
claimed?


Not at all. I think you've misunderstood what is shown on the
RealClimate site. We show that we get essentially the same result, even if
you don't use PCA on the network at all, but use all 95 records available
separately. This is, in our view, the simplest possible demonstration one could
imagine that MM's claims are false. The MBH98 reconstruction doesn't depend
on whether PCA is used or not, let alone the centering convention (which, as
noted below, simply changes the order of the leading patterns). The earliest
part of the reconstruction does depend on certain key chronologists. This
was discussed in some detail in our followup paper (the GRL article referred
to earlier) more than 5 years ago, where we are quite clear about the
sensitivity of the earliest reconstructed values (15th century and earlier)
to certain important North American data. So if one eliminate important data
from the dataset, as McIntyre and McKitrick have done in every case, one
will get a different reconstruction. But such a reconstruction, as it will fail
cross-validation, would never be taken seriously by any legitimate
scientist!

I must also refer you to this page here:
http://www.realclimate.org/index.php?p=7
(see also http://www.realclimate.org/index.php?p=11), where it
is made quite clear that numerous reconstructions using entirely different data,
and different methods (or models) come to nearly the same conclusions (i.e.,
the reconstructions are consistent within the estimated uncertainties). It is
the fact that numerous groups come up with the same result that suggests
that the "hockey stick" is indeed robust.

N&T 26/01/2005

--------------------------------------------------------------------
© 2005 - Natuurwetenschap & Techniek
--------------------------------------------------------------------

peroxisome

unread,
Jan 30, 2005, 8:38:13 AM1/30/05
to
Dear James
I am delighted to see that someone is raising a scientific issue.
I would very much like to examine what you are saying. Can you please
point me to Mann's reponse on this point ? The realclimate blog is full
of so many "comprehensive refutations" it is difficult to follow, and I
believe the rutherford paper is not published yet.
I am not sure if some of the points you raise aren't addressed in the
first point at:
http://www.climate2003.com/mann.responses.htm

It seems that Mann et al are coming awfully close to accepting the
proposition that one pine series, containing only one tree for a good
part of this analysis, changes their "Northern hemisphere" temperature
record !

Under any circumstances, there seems to be a very important point here.
Full disclosure enables analysis of what your science is. The centred/
non-centred PCA wasn't disclosed in MBH98; yet M&M are arguing that it
makes a substantial difference to the end result.
cheers
per

James Annan

unread,
Jan 30, 2005, 8:58:16 AM1/30/05
to
peroxisome wrote:

> Dear James
> I am delighted to see that someone is raising a scientific issue.
> I would very much like to examine what you are saying. Can you please
> point me to Mann's reponse on this point ? The realclimate blog is full
> of so many "comprehensive refutations" it is difficult to follow, and I
> believe the rutherford paper is not published yet.

I was talking about Mann's claim that even with zero-centred data, the
sharp rise in the 20th century appears in the PC series, albeit not PC1,
and that a recontruction of the total temperature series yields
essentially the same results irrespective of which method is used.

http://www.realclimate.org/index.php?p=98

Furthermore, MM's attempts seem to be skill-free - so all they can claim
is that the data (analysed by their method) does not show anything.
Which doesn't mean that a better method cannot generate useful results.

http://www.realclimate.org/index.php?p=111

I'll also note in passing that the late-centred method of MBH does NOT
tend to generate a trend in the 20th century of the PC1. It actually
generates a PC1 with a *step change* at the break-point (eg 1900, if you
set the 1900-1980 mean to be zero). Of course, with a lucky set of
random numbers, you might get something that looks like a positive trend
over that interval. In a previous ms, MM applied a heavy smoothing to
their output which of course turns the step into a slope. I haven't
bothered looking to see is they are still doing this now.

But basically I can't be bothered going over this. I am not going to
particularly defend MBH on the matter - their behaviour seems to have
been less than exemplary, although I can understand their patience
having been sorely tried by the malicious trolling. But a fair bit of
what MM have done seems specious and simply wrong. I fully expect a
robust rebuttal to appear in the relevant journals shortly. No matter:
the septics will continue to claim that there is no warming, or that it
is all just too uncertain, and cite MM as "proof".

peroxisome

unread,
Jan 30, 2005, 10:09:07 AM1/30/05
to
>I was talking about Mann's claim that even with zero-centred ­data,
the
>sharp rise in the 20th century appears in the PC series, alb­eit not
PC1,
I am not a statistician, but I would have thought it was quite
important when your method of data pretreatment changes your analysis
drastically. According to MBH in your links, the pine signal
(hockeystick) shifts from the PC1 to PC4 !

Is the line of argument "our methods were wrong; but we got the right
result" ?

>But basically I can't be bothered going over this.<snip>
> But a fa­ir bit of


>what MM have done seems specious and simply wrong.

Dear James,
I understand your difficulty; after all, why bother with data, logic
and peer-reviewed science, when you have made your mind up that MM are
simply wrong ?
yours
per

Harold Brooks

unread,
Jan 30, 2005, 10:29:30 AM1/30/05
to
In article <1107092751.4...@c13g2000cwb.googlegroups.com>,
perox...@ntlworld.com says...

The referee's comments to authors never have been intended to be
publicly available in my experience as an author, referee, and journal
editor.

Harold
--
Harold Brooks
hebrooks87 hotmail.com

peroxisome

unread,
Jan 30, 2005, 11:18:36 AM1/30/05
to
>The referee's comments to authors never have been intended t­o be
>publicly available in my experience as an author, referee, a­nd
journal
>editor.
>Harold
I have seen referee's comments to authors, both accepting and rejecting
for publication. None have ever been marked confidential.

I am quite clear that in the UK, these comments are treated as public.
I know this, because I know someone who was an editor for a journal.
One of his important jobs was to ensure that referee's comments that
were defamatory were not returned to the author; and these are
relatively common. I am quite clear that if a referee makes defamatory
comment, I have a perfect right to commence proceedings in a court of
law seeking damages. I have also seen referee's comments relating to
other people's publications; so yet another test that there is no
confidentiality.

It may be that there is normally insufficient interest to justify
making referee's comments widely public. That is a different issue.
yours
per

w...@bas.ac.uk

unread,
Jan 30, 2005, 11:31:10 AM1/30/05
to
peroxisome <perox...@ntlworld.com> wrote:
>>It is common ground that this corrigendum corrects numero­us and
>>significant errors in MBH 98.
>> >This is silly.
>Let me quote to you what the corrigendum says.
>"the listing of the 'proxy' data set in the Supplementary
>Information published with this Article contained several errors."
>So when I say that the corrigendum corrects significant errors...

You are snidely attempting to imply that the errors are substantive and
affect the results, which of course they don't.

>> > Its common ground that the corrigendum makes ­*absolutely
>> > no difference to the results*
>MBH assert that their corrigendum makes no difference to the results.

And indeed said so in the corrigendum, published in Nature, so we can
assume that Nature are happy with it too.

>However, I am not aware the M&M have accepted this; indeed, I believe
>that they objected in writing to this phrase.

Nice. And Nature told them where to get off.

w...@bas.ac.uk

unread,
Jan 30, 2005, 11:34:24 AM1/30/05
to
peroxisome <perox...@ntlworld.com> wrote:
>wmc:

>>Not having read MM05 yet, I d­on't know if
>>it falls into that class.

>I know you have strongly held views on this subject...

No, I think thats taking it too far. I have been interested enough to
investigate... see http://www.wmconnolley.org.uk/sci/mbh/ if you're
interested. My investigations don't bear out M&M's claims. So at the
moment I believe Mann. You're keen on preprints: I'm sure you've
read Rutherford et al?

I still find your obsession with just this one topic deeply suspicious.
I strongly suspect you of having undisclosed connections in this matter.

w...@bas.ac.uk

unread,
Jan 30, 2005, 11:38:10 AM1/30/05
to
peroxisome <perox...@ntlworld.com> wrote:
>>I was talking about Mann's claim that even with zero-centred 苓ata,
>the
>>sharp rise in the 20th century appears in the PC series, alb苟it not
>PC1,

>I am not a statistician, but I would have thought it was quite
>important when your method of data pretreatment changes your analysis
>drastically. According to MBH in your links, the pine signal
>(hockeystick) shifts from the PC1 to PC4 !

I think this is your problem: you're don't really understand any of
the issues, but have nonetheless firmly made up your mind. JA's
comments about the method being used to reconstruct the time series
are important: exactly what appears as PC1/2/3/4 is much less important.
You need to think about those comments: if you don't understand them,
you don't understand this at all.

w...@bas.ac.uk

unread,
Jan 30, 2005, 11:39:19 AM1/30/05
to

Referees comments should be considered confidential to the authors unless
given permission to disclose them. M&M got into trouble over this before,
and were obliged by Nature to remove some confidential comments they
had put up.

peroxisome

unread,
Jan 30, 2005, 11:53:50 AM1/30/05
to
>You are snidely attempting to imply that the errors are subs­tantive

and
>affect the results, which of course they don't.
well, I have stated clearly that MBH's case is that their mistakes only
affect their description of what they did, not their underlying data or
results. I have said that the MBH correction corrects errors (MBH's
position), and that the correction is significant (Nature's stated
position). These are matters of fact. Any snide implications are in
your imagination.

I am having trouble with your logic. When you wrote:
>> > Its common ground that the corrigendum makes ­*absolute­ly


>> > no difference to the results*

you must have been aware that MM dispute this. How can you possibly
describe this position as common ground ?
yours
per

peroxisome

unread,
Jan 30, 2005, 12:12:59 PM1/30/05
to
>My investigations don't bear out M&M's claims.
I lifted this from your site:
>>So... M&M do have a partial point: the PC1 shapes
>>(PC1 is the one in black) do tend to have a trend in 1900-on.

So when M&M make a point you can verify, they have a "partial point";
but anything wrong, and your investigations don't bear out M&M's
claims.

In faith, I am a bit bemused. You have access to MM's scripts; I don't
know what your access to MBH's stuff is like; and you have your own
data. Presumably you can now resolve the contradictions in the
analysis, and tell what the errors are and why ? This would be a
constructive way forward ?

Err, no I don't have access to Rutherford el al 2005. Is it available
on the web ?

It is interesting that you find a contrary view to your own to be
deeply suspicious; and that you suspect i have "undisclosed
connections". You will find that if you wear a tin-foil hat, people
won't be able to see what you are thinking !

per

Joshua Halpern

unread,
Jan 30, 2005, 12:23:32 PM1/30/05
to
peroxisome wrote:
>>I thought referee comments were supposed to remain confidenti苔l

>
> Referees frequently have the opportunity of providing advice to the
> editor which may well be confidential; but it is also standard practice
> to provide the authors with comments from the referee which are written
> to be publically available.
> yours
>
No they are not.

josh halpern

peroxisome

unread,
Jan 30, 2005, 12:30:32 PM1/30/05
to
>I think this is your problem: you're don't really understand­ any of
>the issues, but have nonetheless firmly made up your mind. J­A's

>comments about the method being used to reconstruct the time­ series
>are important: exactly what appears as PC1/2/3/4 is much les­s
important.
>You need to think about those comments: if you don't underst­and

them,
>you don't understand this at all.

Dear W
thank you for your condescencion. According to M&M, with non-centring,
the PC1 accounts for 38% of the North American variance; with centring,
the PC4 accounts for only 8 % of the variance. Maybe you can explain
why this is not important ?

I think I am beginning to understand what it means when a series with
one tree affects the whole of the 15th century reconstruction. I think
I am beginning to understand that it is common ground that MBH98 is
absolutely dependent on the North American bristlecone pine series; and
that the relationship between growth and temperature for these series
is not clear cut. But hey; forget the detail. They got the right
result.
per

Thomas Palm

unread,
Jan 30, 2005, 12:35:41 PM1/30/05
to
"peroxisome" <perox...@ntlworld.com> wrote in
news:1107101916.2...@c13g2000cwb.googlegroups.com:

>>The referee's comments to authors never have been intended t觔 be
>>publicly available in my experience as an author, referee, a要d


> journal
>>editor.
>>Harold
> I have seen referee's comments to authors, both accepting and rejecting
> for publication. None have ever been marked confidential.

It may be an unwritten rule, but a rule nevertheless.



> I am quite clear that in the UK, these comments are treated as public.
> I know this, because I know someone who was an editor for a journal.
> One of his important jobs was to ensure that referee's comments that
> were defamatory were not returned to the author; and these are
> relatively common.

That doesn't mean that the comments are public, only that the journal
doesn't want to infuriate an author who might send them better articles
in the future and who they may want to use as referees for other papers.
It is also valuable to censor the most inflammatory reviews because
otherwise there may be an inflation in defamation as people who read
harsh reviews will start to write ones themselves. It's better for the
editors to try to keep the referees as polite as possible.

> I am quite clear that if a referee makes defamatory
> comment, I have a perfect right to commence proceedings in a court of
> law seeking damages.

I'm not sure it has ever happened, but if it did it would be because the
referee defamed the author with respect to the journal, preventing him
from publishing the article.

> I have also seen referee's comments relating to
> other people's publications; so yet another test that there is no
> confidentiality.

Publications are, of course, not confidential so why shouldn't referees
be able to talk about them?



> It may be that there is normally insufficient interest to justify
> making referee's comments widely public. That is a different issue.
> yours

No, it is simply not considered ethical. That's why you only find people
like M&M who are not scientists doing it. The review system is based on
referees being able to remain anonymous, and if the reviews start getting
published people will often be able to guess from the way it is written
who wrote it, and that will mean the referees won't dare be as honest as
they should be in many cases.

peroxisome

unread,
Jan 30, 2005, 12:35:54 PM1/30/05