July 19, 2018
Dear Friends and Family,
This is Segment 7 of the Climate Change Series. It is the first of two skeptic counterpoints to Michael Mann’s Hockey Stick (Segment 6). The excerpts used in the counterpoint come from The Hockey Stick Illusion by A. W. Montford and Unstoppable Global Warming by Fred Singer and Dennis Avery.
This segment gets quite technical. For those of you who enjoy getting into technical scientific detail, you will find this most interesting on a number of fronts. For those who don’t, you may possibly find it frustrating. So, in an attempt to avoid any frustration, I will take a stab at a simplified explanation of what the authors are attempting to convey.
2. In using proxy date to determine temperatures in eras where no thermometers existed, Dr. Mann used tree core data from a single tree that had been strip-barked. This resulted in data that was highly flawed.
3. Some of the historical proxy temperature data was manipulated to exclude some warmer temperature data in the Medieval Warm Period
4. Some of the statistical methodology utilized by Dr. Mann was not recognized as providing accurate analysis by the scientific community.
5. In the final analysis: Dr. Mann’s Hockey Stick shape comes from two sets of flawed proxies in his data base – the bristlecone tree ring proxies and the Tijander proxies from Finland.
I hope this helps. You will have to draw your own conclusions on whether these assertions are valid, how much they impact the validity of the Hockey Stick, and how important the Hockey Stick is to the overall Climate Change debate.
The following are the answers from The Hockey Stick Illusion and Unstoppable Global Warming books relative to the list of questions we utilized in the introductory parts of segments 2 through 6.
1. Is there a 20th century temperature rising trend acknowledged? Yes
2. Is that trend attributed to fossil fuel emissions? No. The Hockey Stick Illusion is devoted to exposing the flaws of data gathering, data flaws, miscalculations, and misrepresentations in Dr. Michael Mann’s creation of the “Hockey Stick.” In doing so, the author concludes there was indeed a Medieval Warm Period with temperatures greater than today devoid of any fossil fuels emissions. The second referenced book Unstoppable Global Warming reports the same thing, as illustrated in this graph (published in Wikipedia, https://commons.wikimedia.org/wiki/File:NH_temperature_2ka.png.)
Dear Friends and Family,
This is Segment 7 of the Climate Change Series. It is the first of two skeptic counterpoints to Michael Mann’s Hockey Stick (Segment 6). The excerpts used in the counterpoint come from The Hockey Stick Illusion by A. W. Montford and Unstoppable Global Warming by Fred Singer and Dennis Avery.
This segment gets quite technical. For those of you who enjoy getting into technical scientific detail, you will find this most interesting on a number of fronts. For those who don’t, you may possibly find it frustrating. So, in an attempt to avoid any frustration, I will take a stab at a simplified explanation of what the authors are attempting to convey.
- The first International Panel on Climate Change (IPCC) assessment report stated that it wasn’t yet possible to attribute any significant temperature increase trend due to an increase in greenhouse gases. The third IPCC assessment report stated the greenhouse effect was the primary contributor to the temperature increase starting in 1880 and it was unique in the planet’s history, because of fossil fuels emissions. The change in the IPCC’s perspective between the first and third assessment was due primarily to the Hockey Stick technical analysis.
- A. W. Montford reports that the technical work supporting the Hockey Stick was very sloppy, lacked transparency in the sources of data, and contained numerous mistakes. The mistakes and/or misrepresentations included:
2. In using proxy date to determine temperatures in eras where no thermometers existed, Dr. Mann used tree core data from a single tree that had been strip-barked. This resulted in data that was highly flawed.
3. Some of the historical proxy temperature data was manipulated to exclude some warmer temperature data in the Medieval Warm Period
4. Some of the statistical methodology utilized by Dr. Mann was not recognized as providing accurate analysis by the scientific community.
5. In the final analysis: Dr. Mann’s Hockey Stick shape comes from two sets of flawed proxies in his data base – the bristlecone tree ring proxies and the Tijander proxies from Finland.
I hope this helps. You will have to draw your own conclusions on whether these assertions are valid, how much they impact the validity of the Hockey Stick, and how important the Hockey Stick is to the overall Climate Change debate.
The following are the answers from The Hockey Stick Illusion and Unstoppable Global Warming books relative to the list of questions we utilized in the introductory parts of segments 2 through 6.
1. Is there a 20th century temperature rising trend acknowledged? Yes
2. Is that trend attributed to fossil fuel emissions? No. The Hockey Stick Illusion is devoted to exposing the flaws of data gathering, data flaws, miscalculations, and misrepresentations in Dr. Michael Mann’s creation of the “Hockey Stick.” In doing so, the author concludes there was indeed a Medieval Warm Period with temperatures greater than today devoid of any fossil fuels emissions. The second referenced book Unstoppable Global Warming reports the same thing, as illustrated in this graph (published in Wikipedia, https://commons.wikimedia.org/wiki/File:NH_temperature_2ka.png.)
Note: The Medieval Warming period extended from 900 to 1300 and the Little Ice Age was from 1300 until 1850.
3. What is the evidence in support of point 2 above?
-- Miscalculation of multi-variant proxies.
-- Use of non-validated principal component (PC) analyses.
-- Arbitrarily filling in missing data in proxy data series
-- Substituting summer average temperatures for annual average temperatures.
-- Shortening the time series on temperature data to flatten the Little Ice Age temperatures and to discard the warmest 25 years of the Medieval Warm Period.
-- Use of two flawed proxies for reconstructed temperature data – specifically Bristlecone pines and Tijander lake sediment in Finland.
4. Is the trend attributed to natural causes? For the most part yes
5. Are there severe consequences predicted? No
6. Is there any additional scientific information presented concerning the debate? No
The next segment will be the second of two counterpoint segments to Dr. Mann’s Hockey Stick book. The segment excerpts will come from A Disgrace to the Profession which contains different viewpoints from 120 different people in the scientific community. The book was compiled and edited by Mark Steyn.
Happy Learning,
Harley
-- Miscalculation of multi-variant proxies.
-- Use of non-validated principal component (PC) analyses.
-- Arbitrarily filling in missing data in proxy data series
-- Substituting summer average temperatures for annual average temperatures.
-- Shortening the time series on temperature data to flatten the Little Ice Age temperatures and to discard the warmest 25 years of the Medieval Warm Period.
-- Use of two flawed proxies for reconstructed temperature data – specifically Bristlecone pines and Tijander lake sediment in Finland.
4. Is the trend attributed to natural causes? For the most part yes
5. Are there severe consequences predicted? No
6. Is there any additional scientific information presented concerning the debate? No
The next segment will be the second of two counterpoint segments to Dr. Mann’s Hockey Stick book. The segment excerpts will come from A Disgrace to the Profession which contains different viewpoints from 120 different people in the scientific community. The book was compiled and edited by Mark Steyn.
Happy Learning,
Harley
CLIMATE CHANGE – SEGMENT 7
THE HOCKEY STICK FIRST COUNTERPOINT – EXCERPTS
From The Hockey Stick Illusion by A.W. Montford
THE IPCC'S FIRST ASSESSMENT REPORT: In the executive summary the report's authors said
THE HOCKEY STICK FIRST COUNTERPOINT – EXCERPTS
From The Hockey Stick Illusion by A.W. Montford
THE IPCC'S FIRST ASSESSMENT REPORT: In the executive summary the report's authors said
We conclude that despite great limitations in the quantity and quality of the available historical temperature data, the evidence points consistently to a real but irregular warming over the last century. A global warming of larger size has almost certainly occurred at least once since the end of the last glaciation without any appreciable increase in greenhouse gases. Because we do not understand the reason for these past warming events, it is not yet possible to attribute a specific proportion of the recent, smaller warming to an increase of greenhouse gases.
Their words show what the global warming movement faced. If they were going to persuade policymakers to vote them still more funds and to take drastic action in terms of changing the working of the economy and the way people lived, it was going to be necessary to persuade the public as well, and the public were unlikely to be convinced by science that was sparse and limited in quality. The report included a chart showing how global temperatures had varied in previous ages. This was something of a dampener for the argument for catastrophic global warming because it suggested that past temperatures had been warmer than today in a long period lasting from the 11th to the 15th centuries. This period had been followed by two or three hundred years of much cooler temperatures lasting until the 18th century. Since then warming had recommenced, but current temperatures were still thought to be well short of those reached during the medieval warming. This then was a huge problem for those promoting the idea of global warming – how would they convince anyone that a rise of a fraction of a degree in temperature portended something dangerous when the climate had been much warmer in the past? Climate science wanted big funding and big political action; that was going to require definitive evidence. In order to strengthen the arguments for the current warming being unprecedented, there was going to have to be a major study to present evidence that the Medieval Warm Period was a chimera. Enter the Hockey Stick.
THE HOCKEY STICK: The Hockey Stick paper, written by Michael Mann, made its grand entrance in an article published in Nature on April 23, 1998. The key graphic in the paper was a chart on the reconstruction of Northern Hemisphere temperatures for the full length of the record from 1400 right through to 1980. The picture presented was crystal clear. From the very beginning of the series the temperature line meandered gently, first a little warmer, then a little cooler, never varying more than half a degree or so from peak to trough. This was the 500-year-long handle of the Hockey Stick, a sort of steady state that had apparently reigned, unchanging, throughout most of recorded history. Then suddenly, the blade of the stick appeared at the start of the 20th century, shooting upwards in an almost straight line. It was a startling change. The Medieval Warm Period had vanished. The conclusions were stark: current temperatures were unprecedented.
The two Hockey Stick papers were good for Mann. Within months of the first paper’s publication, he found himself advancing rapidly through the academic ranks with a speed that was breathtaking. Prizes and titles flowed his way too, with papers he has written lauded on all sides. In 2002, Scientific American selected him as one of the 50 leading visionaries in science. One of Mann’s most significant accolades was his appointment as the lead author of the paleoclimate chapter in the IPCC’s Third Assessment Report of 2001. Again, we can only stand back in admiration that someone who had published his PhD a matter of a year or so earlier could be invited to head the team writing one of the most critical chapters in one of the most important scientific reports for decades. Mann’s position as lead author did present an apparent problem, however, since in that position he had a clear conflict of interest in assessing the published literature – he was going to be considering his own work. It is unfortunate then that the Hockey Stick was given extraordinary prominence in the Third Assessment Report, particularly in Mann’s own chapter on paleoclimate.
CLIMATE SKEPTIC INVESTIGATION: At the start of 2003 a short comment was posted on an Internet forum for global warming skeptics by a Dutchman. Hans Erren. He had developed an interest in Mann’s 1999 update on the Hockey Stick and had decided to dig into the study in a little more detail. It quickly became apparent to him that it was not a simple task. Mann’s paper was opaque and difficult to understand. He could make little sense of the way the proxies were calibrated against temperature, for example. So, as people in the skeptic community would often do in these circumstances, he threw the question open to the forum to see if anyone could help or shed any light on the problem. One responder was Steve McIntyre, a semi-retired mining consultant from Toronto. McIntyre became absorbed in reading the IPCC’s Third Assessment Report with its prominent display of the Hockey Stick. To someone with long experience of mining promotions it immediately struck McIntyre that someone had spent a great deal of time and money making an effective sales tool out of Mann’s graph. McIntyre was used to the corporate world, where tight regulation and nervous investors meant that clear explanations of method and results were an absolute necessity. In the mining industry, a garbled explanation of what a drill core contained would send potential investors running for the door, so McIntyre had been completely bemused by the obscure language and vague allusions that littered Mann’s papers.
MBH98 involved a multivariate calibration – in other words here were multiple sets of data needing to be calibrated: the 112 proxies and the 16 temperature PCs. But how Mann had gone about this complex process was a mystery that was not revealed in the text of the paper.
The use of PC analysis was new in the realm of paleoclimate and Mann had made no attempt to prove the validity of the technique, instead relying on a bold assertion that it was better than the alternative.
Digging into the proxy records turned up a different kind of error: proxy number 45 had the same value in every year from 1978 to 1982. Series 46, on the other hand was identical from 1974 to 1980. Series 51 was the same as was 52, 54, 56, and 58. It looked as though some of the numbers had been missing from the series, and rather than discard the proxy or locating the missing data, someone had infilled the missing numbers with the final available figure. Most of the infilling was happening during the modern era which is when you would expect it to be easiest to obtain complete data, but importantly it was during the calibration. Inaccurate results here would have a direct knock-on effect on the reconstruction of historical temperatures. In all, more than a third of the series had been affected in this way, and for Mann to have been fair to the reader this should have been disclosed, together with some assessment of the potential impact on the reconstruction. It got worse, series 10 and 11 were two instrumental records – actual temperatures. When McIntyre checked these back to the original publicly archived data he found that the figures didn’t match. Where was Mann getting his numbers from? With a little digging the answer turned out to be that figures were actually based on the average of June, July, and August for each year, rather than the full year average. The problem with this was Mann was trying to recreate an annual average temperature, not a summer average.
The Central Europe Temperature Record (CETR) is one of the oldest uninterrupted temperature records in the world. It was started in the year 1659, giving it the best part of 350 years of uninterrupted measurements. It is hard then to understand why Mann should have truncated the record at 1730, reducing the length of the series to 250 years. Cynical observers might, however, have noticed that the late 17th century numbers for CETR were distinctly cold, so the effect of this truncation may well have been to flatten the Little Ice Age. When McIntyre transferred his attentions to the Central Europe series, he came across a similar problem – the data had been truncated at 1550, when the full series went back to 1525. Here the warmest part of the record was removed from the series, and the effect was presumably to flatten the Medieval Warm Period. In neither case were these truncations disclosed or justified.
McIntyre emailed Mann again to try to get clarification of some the ambiguous calculation steps but received little useful information in return. He was going to have to reconcile his own work to Mann’s. With a good approximation of Mann’s methodology, McIntyre now reached the moment of truth. It was clear that the hunches he’s had when looking through the graphs of the proxies were entirely borne out. With the database corrected, the handle of the Hockey Stick was warped – that is to say, there was a pronounced Medieval Warm Period. In fact, the temperatures of the reconstructed 15th century were higher than those reached in the 20th.
McIntyre’s findings were clearly going to be highly controversial and it was therefore important to make the paper scientifically watertight. To make sure nothing had been missed, he and McKitrick recruited a number of external reviewers to examine the findings and the draft paper. Then, to check that their work was unassailable from a statistical perspective, they also commissioned a review from a professional statistician with paleoclimate expertise. The paper was published on October 27, 2003. Mann’s reply was just as forthright as his previous pronouncements on McIntyre and McKitrick’s work. He took issue with almost all of the paper, saying that the two Canadians were “incorrect with respect to each major point” they raised and that their work did “not demand serious consideration.” However, Mann put up no substantive defense of his use of an obsolete data version. McIntyre had discovered that the early part of the series was based on only a single tree, which appeared to be the reason this part of the record had been removed. They were all from bristlecone pines and all had been collected by a single researcher, Donald Graybill. These records all had a distinct hockey stick shape with a dramatic growth spurt in the 20th century but unremarkable growth levels in the 15th century. About the same time a new source of evidence about the origins of the growth spurt in bristlecone pines. A student at the University of Arizona published her thesis on the difference between the stripbark and wholebark trees, specifically looking at sites visited by Graybill. It was immediately apparent that her results didn’t confirm the existence of the growth spurt that Graybill had reported. The significance of these findings is hard to overestimate: not only had Mann used incorrect statistics to force his temperature reconstruction into the hockey stick shape of the bristlecone pines, but it now appeared as though the shape was merely and artifact of stripbarking. Nor was MBH98 the only paper where Sheep Mountain was a key proxy. The results now seemed unarguable. Evidence from multiple sources was now demonstrating unequivocally that the bristlecone pines, which gave the Hockey Stick its attention-grabbing shape, were not in fact capturing temperature information at all. After so many flaws had been uncovered and demonstrated to the satisfaction of all but its most dogmatic supporters, surely the Hockey Stick was broken.
A NEW HOCKEY STICK: Despite all the evidence that proxy records were not reaching new levels in the 20th century, Mann was apparently still maintaining that modern temperatures were unprecedented: the new study was another hockey stick, this time suggesting that modern temperature were the highest they had been in 1300 years. There were some new data series as well and McIntyre started to post graphs of these for his readers to view. They were devoured, several people noticing few of them showed any modern warming. The sole exception among the first batch was a group of four lake sediment series from Finland, known as the Tijander proxies. I turned out that the 20th century uptick in Tijander’s proxies was caused by artificial disturbance of the sediment caused by ditch digging, rather than anything climatic. Mann had shown that the Tijander proxis were valid by removing them from the database and showing that you still got a hockey stick. However, when he did this test, the hockey shape of the final reconstruction came from the bristlecones. Then he argues that he could remove the tree ring proxies (including the bristlecones) and still get a hockey stick – and of course he could, because in this case the hockey stick shape came from the Tijander proxies. His arguments therefore rested on having two sets of flawed proxies in the database, but only removing one at a time. He could then argue that he still got the hockey stick either way.
SUMMARY: The Hockey Stick was, from the very beginning, a test of the IPCC’s impartiality. It was clear before the publication of Mann’s paper that the Medieval Warm Period was a major problem for those who argued that man’s activities were having an adverse effect of the climate. The public would simply not be convinced of the case for drastic action if temperatures appeared to have been warmer a few hundred years ago. The arrival of the Hockey Stick and its startling rise to prominence should have given the IPCC pause for thought on these grounds alone. Their handling of the paper represented an opportunity for IPCC officials to demonstrate that their organization could be an “honest broker” between the environmentalists and skeptics, a chance for it to show that its procedures were fair and balanced and that it could be a reliable source of advice to politicians. On each count, its failure was complete and catastrophic. It has chosen to be an advocate rather than a judge.
There is one final aspect to the story of the National Academy of Science (NAS) panel on the hockey stick that bears repeating. In the aftermath of the Hockey Stick report Gerry North, panel leader, was in much demand, and one of the lectures he gave on the panels work gave some interesting insights into the nature of their review. North explained to the audience the way the panel had worked.
THE HOCKEY STICK: The Hockey Stick paper, written by Michael Mann, made its grand entrance in an article published in Nature on April 23, 1998. The key graphic in the paper was a chart on the reconstruction of Northern Hemisphere temperatures for the full length of the record from 1400 right through to 1980. The picture presented was crystal clear. From the very beginning of the series the temperature line meandered gently, first a little warmer, then a little cooler, never varying more than half a degree or so from peak to trough. This was the 500-year-long handle of the Hockey Stick, a sort of steady state that had apparently reigned, unchanging, throughout most of recorded history. Then suddenly, the blade of the stick appeared at the start of the 20th century, shooting upwards in an almost straight line. It was a startling change. The Medieval Warm Period had vanished. The conclusions were stark: current temperatures were unprecedented.
The two Hockey Stick papers were good for Mann. Within months of the first paper’s publication, he found himself advancing rapidly through the academic ranks with a speed that was breathtaking. Prizes and titles flowed his way too, with papers he has written lauded on all sides. In 2002, Scientific American selected him as one of the 50 leading visionaries in science. One of Mann’s most significant accolades was his appointment as the lead author of the paleoclimate chapter in the IPCC’s Third Assessment Report of 2001. Again, we can only stand back in admiration that someone who had published his PhD a matter of a year or so earlier could be invited to head the team writing one of the most critical chapters in one of the most important scientific reports for decades. Mann’s position as lead author did present an apparent problem, however, since in that position he had a clear conflict of interest in assessing the published literature – he was going to be considering his own work. It is unfortunate then that the Hockey Stick was given extraordinary prominence in the Third Assessment Report, particularly in Mann’s own chapter on paleoclimate.
CLIMATE SKEPTIC INVESTIGATION: At the start of 2003 a short comment was posted on an Internet forum for global warming skeptics by a Dutchman. Hans Erren. He had developed an interest in Mann’s 1999 update on the Hockey Stick and had decided to dig into the study in a little more detail. It quickly became apparent to him that it was not a simple task. Mann’s paper was opaque and difficult to understand. He could make little sense of the way the proxies were calibrated against temperature, for example. So, as people in the skeptic community would often do in these circumstances, he threw the question open to the forum to see if anyone could help or shed any light on the problem. One responder was Steve McIntyre, a semi-retired mining consultant from Toronto. McIntyre became absorbed in reading the IPCC’s Third Assessment Report with its prominent display of the Hockey Stick. To someone with long experience of mining promotions it immediately struck McIntyre that someone had spent a great deal of time and money making an effective sales tool out of Mann’s graph. McIntyre was used to the corporate world, where tight regulation and nervous investors meant that clear explanations of method and results were an absolute necessity. In the mining industry, a garbled explanation of what a drill core contained would send potential investors running for the door, so McIntyre had been completely bemused by the obscure language and vague allusions that littered Mann’s papers.
MBH98 involved a multivariate calibration – in other words here were multiple sets of data needing to be calibrated: the 112 proxies and the 16 temperature PCs. But how Mann had gone about this complex process was a mystery that was not revealed in the text of the paper.
The use of PC analysis was new in the realm of paleoclimate and Mann had made no attempt to prove the validity of the technique, instead relying on a bold assertion that it was better than the alternative.
Digging into the proxy records turned up a different kind of error: proxy number 45 had the same value in every year from 1978 to 1982. Series 46, on the other hand was identical from 1974 to 1980. Series 51 was the same as was 52, 54, 56, and 58. It looked as though some of the numbers had been missing from the series, and rather than discard the proxy or locating the missing data, someone had infilled the missing numbers with the final available figure. Most of the infilling was happening during the modern era which is when you would expect it to be easiest to obtain complete data, but importantly it was during the calibration. Inaccurate results here would have a direct knock-on effect on the reconstruction of historical temperatures. In all, more than a third of the series had been affected in this way, and for Mann to have been fair to the reader this should have been disclosed, together with some assessment of the potential impact on the reconstruction. It got worse, series 10 and 11 were two instrumental records – actual temperatures. When McIntyre checked these back to the original publicly archived data he found that the figures didn’t match. Where was Mann getting his numbers from? With a little digging the answer turned out to be that figures were actually based on the average of June, July, and August for each year, rather than the full year average. The problem with this was Mann was trying to recreate an annual average temperature, not a summer average.
The Central Europe Temperature Record (CETR) is one of the oldest uninterrupted temperature records in the world. It was started in the year 1659, giving it the best part of 350 years of uninterrupted measurements. It is hard then to understand why Mann should have truncated the record at 1730, reducing the length of the series to 250 years. Cynical observers might, however, have noticed that the late 17th century numbers for CETR were distinctly cold, so the effect of this truncation may well have been to flatten the Little Ice Age. When McIntyre transferred his attentions to the Central Europe series, he came across a similar problem – the data had been truncated at 1550, when the full series went back to 1525. Here the warmest part of the record was removed from the series, and the effect was presumably to flatten the Medieval Warm Period. In neither case were these truncations disclosed or justified.
McIntyre emailed Mann again to try to get clarification of some the ambiguous calculation steps but received little useful information in return. He was going to have to reconcile his own work to Mann’s. With a good approximation of Mann’s methodology, McIntyre now reached the moment of truth. It was clear that the hunches he’s had when looking through the graphs of the proxies were entirely borne out. With the database corrected, the handle of the Hockey Stick was warped – that is to say, there was a pronounced Medieval Warm Period. In fact, the temperatures of the reconstructed 15th century were higher than those reached in the 20th.
McIntyre’s findings were clearly going to be highly controversial and it was therefore important to make the paper scientifically watertight. To make sure nothing had been missed, he and McKitrick recruited a number of external reviewers to examine the findings and the draft paper. Then, to check that their work was unassailable from a statistical perspective, they also commissioned a review from a professional statistician with paleoclimate expertise. The paper was published on October 27, 2003. Mann’s reply was just as forthright as his previous pronouncements on McIntyre and McKitrick’s work. He took issue with almost all of the paper, saying that the two Canadians were “incorrect with respect to each major point” they raised and that their work did “not demand serious consideration.” However, Mann put up no substantive defense of his use of an obsolete data version. McIntyre had discovered that the early part of the series was based on only a single tree, which appeared to be the reason this part of the record had been removed. They were all from bristlecone pines and all had been collected by a single researcher, Donald Graybill. These records all had a distinct hockey stick shape with a dramatic growth spurt in the 20th century but unremarkable growth levels in the 15th century. About the same time a new source of evidence about the origins of the growth spurt in bristlecone pines. A student at the University of Arizona published her thesis on the difference between the stripbark and wholebark trees, specifically looking at sites visited by Graybill. It was immediately apparent that her results didn’t confirm the existence of the growth spurt that Graybill had reported. The significance of these findings is hard to overestimate: not only had Mann used incorrect statistics to force his temperature reconstruction into the hockey stick shape of the bristlecone pines, but it now appeared as though the shape was merely and artifact of stripbarking. Nor was MBH98 the only paper where Sheep Mountain was a key proxy. The results now seemed unarguable. Evidence from multiple sources was now demonstrating unequivocally that the bristlecone pines, which gave the Hockey Stick its attention-grabbing shape, were not in fact capturing temperature information at all. After so many flaws had been uncovered and demonstrated to the satisfaction of all but its most dogmatic supporters, surely the Hockey Stick was broken.
A NEW HOCKEY STICK: Despite all the evidence that proxy records were not reaching new levels in the 20th century, Mann was apparently still maintaining that modern temperatures were unprecedented: the new study was another hockey stick, this time suggesting that modern temperature were the highest they had been in 1300 years. There were some new data series as well and McIntyre started to post graphs of these for his readers to view. They were devoured, several people noticing few of them showed any modern warming. The sole exception among the first batch was a group of four lake sediment series from Finland, known as the Tijander proxies. I turned out that the 20th century uptick in Tijander’s proxies was caused by artificial disturbance of the sediment caused by ditch digging, rather than anything climatic. Mann had shown that the Tijander proxis were valid by removing them from the database and showing that you still got a hockey stick. However, when he did this test, the hockey shape of the final reconstruction came from the bristlecones. Then he argues that he could remove the tree ring proxies (including the bristlecones) and still get a hockey stick – and of course he could, because in this case the hockey stick shape came from the Tijander proxies. His arguments therefore rested on having two sets of flawed proxies in the database, but only removing one at a time. He could then argue that he still got the hockey stick either way.
SUMMARY: The Hockey Stick was, from the very beginning, a test of the IPCC’s impartiality. It was clear before the publication of Mann’s paper that the Medieval Warm Period was a major problem for those who argued that man’s activities were having an adverse effect of the climate. The public would simply not be convinced of the case for drastic action if temperatures appeared to have been warmer a few hundred years ago. The arrival of the Hockey Stick and its startling rise to prominence should have given the IPCC pause for thought on these grounds alone. Their handling of the paper represented an opportunity for IPCC officials to demonstrate that their organization could be an “honest broker” between the environmentalists and skeptics, a chance for it to show that its procedures were fair and balanced and that it could be a reliable source of advice to politicians. On each count, its failure was complete and catastrophic. It has chosen to be an advocate rather than a judge.
There is one final aspect to the story of the National Academy of Science (NAS) panel on the hockey stick that bears repeating. In the aftermath of the Hockey Stick report Gerry North, panel leader, was in much demand, and one of the lectures he gave on the panels work gave some interesting insights into the nature of their review. North explained to the audience the way the panel had worked.
We didn’t do any research in this project, we just took a look at the papers that were existing and we tried to draw some kinds of conclusions from them. So here we had twelve people around the table, all with very different backgrounds from one another and we just kind of winged it to see … so that’s what you do in that kind of expert panel.
North said these words, not with any sense of dissatisfaction or of concern. His tone was matter-of-fact; this was the way things were in expert panels. It was just one more dismaying revelation from the Hockey Stick affair – faced with the most important scientific questions for decades, asked to study and report on a subject of incalculable economic, political and social importance, a group of distinguished scientists get around a table, talked about some papers and just “kind of winged it.”
Source: The Hockey Stick Illusion by A. W. Montford
From: Unstoppable Global Warming by Fred Singer & Dennis Avery (also found in the PDF file attachment of segment 3.
THE “HOCKEY STICK” SCANDAL: The Medieval and Roman warming with their intervening cold periods, present a huge problem for the advocates of man-made global warming. If the Medieval and Roman warming were warmer than today – without greenhouse gases – what would be so unusual about modern times being warm as well? The IPCC’s second assessment report, Climate Change 1995, included a graph of temperatures for the last 1,000 years. It showed a Medieval Warm Period with warmer temperatures than today and a Little Ice Age with temperatures lower than today. Six years later, the IPCC was either bolder or more desperate. In Climate Change 2001, the graph based on a 1998 study led by Michael Mann, a young PhD from the University of Massachusetts. The Mann et al. study used several temperature proxies (but primarily tree rings) as a basis for assessing past temperature changes from 1000 to 1980. He then grafted the surface temperatures recorded for the 20th century onto the pre-1980 proxy record. The effect was visually dramatic. Gone were the Medieval Warming and the Little Ice Age. The Mann study contradicted hundreds of historical sources on the Medieval Warming and Little Ice Age and hundreds of previous scientific papers with evidence of those major past changes in the Earth’s climate. In effect, the IPCC told us to ignore the overwhelming historic and physical evidence that the world’s mean temperatures dropped sharply from about 1300 until at least 1859. They suggested that Earth’s climate didn’t get colder during the Little Ice Age. Global circulation just got a little “constricted.”
Source: Unstoppable Global Warming by Fred Singer & Dennis Avery
The unabbreviated version of the above can be found in the pdf document below.
Source: The Hockey Stick Illusion by A. W. Montford
From: Unstoppable Global Warming by Fred Singer & Dennis Avery (also found in the PDF file attachment of segment 3.
THE “HOCKEY STICK” SCANDAL: The Medieval and Roman warming with their intervening cold periods, present a huge problem for the advocates of man-made global warming. If the Medieval and Roman warming were warmer than today – without greenhouse gases – what would be so unusual about modern times being warm as well? The IPCC’s second assessment report, Climate Change 1995, included a graph of temperatures for the last 1,000 years. It showed a Medieval Warm Period with warmer temperatures than today and a Little Ice Age with temperatures lower than today. Six years later, the IPCC was either bolder or more desperate. In Climate Change 2001, the graph based on a 1998 study led by Michael Mann, a young PhD from the University of Massachusetts. The Mann et al. study used several temperature proxies (but primarily tree rings) as a basis for assessing past temperature changes from 1000 to 1980. He then grafted the surface temperatures recorded for the 20th century onto the pre-1980 proxy record. The effect was visually dramatic. Gone were the Medieval Warming and the Little Ice Age. The Mann study contradicted hundreds of historical sources on the Medieval Warming and Little Ice Age and hundreds of previous scientific papers with evidence of those major past changes in the Earth’s climate. In effect, the IPCC told us to ignore the overwhelming historic and physical evidence that the world’s mean temperatures dropped sharply from about 1300 until at least 1859. They suggested that Earth’s climate didn’t get colder during the Little Ice Age. Global circulation just got a little “constricted.”
Source: Unstoppable Global Warming by Fred Singer & Dennis Avery
The unabbreviated version of the above can be found in the pdf document below.
| 07_cc_long_first_hockey_stick_illusion_--_segment_7.pdf |