Tuesday, August 18, 2009

The IPCC 2500 Climate Scientists and the Consensus of Opinion

The IPCC (AR4) includes reports from the three working groups. Working Group 1 is to report on the extent and possible causes of past climate change and future projections. Working groups 2 and 3 were to report “Impacts, Adaptation and Vulnerability” and “Mitigation of Climate Change” respectively. The WG1 report is approximately 1000 pages long and is highly technical in its information so a Summary for Policy Makers was used to be given and in most cases is the only report read by politicians and non scientists. This Summary is accused of being highly politically motivated in its make up as much detail is removed, altered or watered down so that ordinary people can read it.

Much has been made of this “consensus of scientific opinion” as is often touted from the IPCC (AR4). Most politicians who are advocating the introduction of schemes such as Emissions trading use it as a primary justification of their position. The simple fact remains, however that science should never be done by consensus but by scepticism, testing of theories against practical outcomes and testing of repeatability of results. In fact consensus can lead to corruption of the science as other theories aren’t challenged or tested due to an element of peer pressure to conform and group think eventuates. To demonstrate this Dr. Roy W. Spencer (PhD, Climatologist, Principle Research Scientist, Earth System Science Centre, The University of Alabama, Huntsville) wrote in June 2008:

Proof that this indeed happens is in the recent medical theory that stomach ulcers are caused by bacteria. Two Australian medical researchers were scoffed at by the medical community for 20 years before the bacterial basis explanation was finally accepted.

More famously was the attempt by Nazi Germany to discredit Albert Einstein’s theory of relativity.

The Nazis enlisted other physicists, including Nobel laureates Philip Lenard and Johannes Stark, to denounce Einstein. One Hundred Authors Against Einstein was published in 1931. When asked to comment on this denunciation of relativity by so many scientists, Einstein replied “that to defeat relativity one did not need the word of 100 scientists, just one fact.”

He is also quoted as saying on the issue of scientific consensus: “In order to be an immaculate member of a flock of sheep, one must above all be a sheep oneself.”

But how accurate is this claim about the 2500 top climate scientists advocating that climate change is real and entirely man made? It would seem there is some reason to doubt these figures.

According to an article written by Malcolm Wallop, Quoting Citizens for a Sound Economy he states:
fewer than 10 percent of these “scientists” know anything about climate. Amongst the signers: a plastic surgeon, two landscape architects, a hotel administrator, a gynaecologist, seven sociologists, a linguist, and a practitioner of traditional Chinese medicine.

In another article written by Tom Harris (Mechanical Engineer and Executive Director of the International Climate Science Coalition) and John McLean (PhD, Climate data analyst, computer scientist) called “The UN climate change numbers Hoax” in June 2008
they detailed aspects of the IPCC Working Group 1, how many reviewers commented on the reports 11 chapters and how the IPCC’s editors often ignored or flatly rejected comments from reviewers. In it they wrote the following extracts: (Any emphasis is mine.)

The number of scientist reviewers involved in WG1 is actually less than a quarter of the whole, a little more than 600 in total. The other 1,900 reviewers assessed the other working group reports. They had nothing to say about the causes of climate change or its future trajectory. Still, 600 “scientific expert reviewers” sounds pretty impressive After all, they submitted their comments to the IPCC editors who assure us that “all substantive government and expert review comments received appropriate consideration.” And since these expert reviewers are all listed in Annex III of the report, they must have endorsed it, right?


..An examination of reviewers’ comments on the last draft of the WG1 report before final report assembly (i.e. the Second Order Revision or SOR) completely debunks the illusion of hundreds of experts diligently poring over all the chapters of the report and providing extensive feedback to the editing teams. Here is the reality.

A total of 308 reviewers commented on the SOR, but only 32 reviewers commented on more than three chapters and only five reviewers commented on all 11 chapters of the report. Only about half the reviewers commented on more than one chapter. It is logical that reviewers would generally limit their comments to their areas of expertise but it’s a far cry from the idea of thousands of scientists agreeing to anything.

Compounding this is the fact that the IPCC editors could, and often did, ignore reviewers comments. Some editors responses were banal and others showed inconsistencies with other comments. Reviewers had to justify their requested changes but the responding editors appear to have been under no such obligation. Reviewers were sometimes flatly told they were wrong but no reasons or reliable references were provided.

In other cases reviewers tried to dilute the certainty being expressed and they often provided supporting evidence, but their comments were flatly rejected. Some comments were rejected on the basis of a lack of space – an incredible assertion in such an important document.
The attitude of the editors seemed to be that simple corrections were accepted, requests for improved clarity tolerated but the assertions and interpretations that appear in the text were to be defended against any challenge.

An example of rampant misrepresentation of IPCC reports is the frequent assertion that “hundreds of IPCC scientists” are known to support the following statement, arguably the most important of the WG1 report, namely “Greenhouse gas forcing has very likely caused most of the observed global warming over the last 50 years.”

In total, only 62 scientists reviewed the chapter in which this statement appears, the critical chapter 9, “Understanding and Attributing Climate Change.” Of the comments received from the 62 reviewers of this critical chapter, almost 60 per cent of them were rejected by the IPCC editors. And of the 62 expert reviewers of this chapter, 55 had serious vested interest, leaving only seven expert reviewers who appear impartial.”

…Determining the level of support expressed by reviewers’ comments is subjective but a slightly generous evaluation indicates that just five reviewers endorsed the crucial ninth chapter. Four had vested interests and the other made only a single comment for the entire 11 chapter report. The claim that 2,500 independent scientist reviewers agreed with this, the most important statement of the UN climate reports released this year, or any other statement in the UN climate reports, is nonsense.

This is supported by Dr. Timothy Ball (PhD, environmental consultant, former climatology professor, University of Winnipeg) who wrote:

The IPCC owe it to the world to explain who among their expert reviewers actually agree with their conclusions and who don’t. Other wise, their credibility, and the publics trust of science in general, will be further eroded.

The IPCC assessment reports and processes to produce them are often accused of being political in nature rather than scientific in the way they are put together and the specific wording they use. Professor John Christy (PhD, Professor of Atmospheric Science, University of Alabama, contributor to all four major IPCC assessments, including as a Lead author in 2001 and a Contributing Author in 2007) wrote an article: No consensus on IPCC’s level of ignorance in Nov 2007, detailing some of the inner workings of the IPCC in the lead up to the AR4. Some extracts are: (Any emphasis added is mine)

The IPCC is a framework around which hundreds of scientists and other participants are organised to mine the panoply of climate change literature to produce a synthesis of the most important and relevant findings.

These findings are published every few years to help policy makers keep tabs on where the participants chosen for the IPCC believe the Earth’s climate has been, where it is going, and what might be done to adapt to and/or even adjust the predicted outcome. While most participants are scientists and bring the aura of objectivity, there are two things to note:

This is a political process to some extent (anytime governments are involved it ends up that way)

Scientists are mere mortals casting their gaze on a system so complex we cannot precisely predict its future state even five days ahead.

The political process begins with the selection of the Lead Authors because they are nominated by their own governments.

Thus at the outset, the political apparatus of the member nations has a role in pre-selecting the main participants.

But it may go further.

At an IPCC Lead Authors meeting in New Zealand, I well remember a conversation over lunch with three Europeans, unknown to me but who served as authors on other chapters. I sat at their table because it was convenient.

After introducing myself, I sat in silence as their discussion continued, which boiled down to this: “We must write this report so strongly that it will convince the US to sign the Kyoto Protocol.”

Politics, at least for a few Lead Authors, was very much part and parcel of the process.

The tendency to succumb to group-think and the herd instinct ( now formally called the “informational cascade”) is perhaps as tempting amongst scientists as any group because we, by definition, must be the “ones who know.”

You dare not be thought of as “one who does not know”; hence we may succumb to the pressure to be perceived as “one who knows.”

This leads, in my opinion, to an overstatement of confidence in the published findings and a ready acceptance of the views of anointed authorities.

Scepticisms, a hallmark of science, is frowned upon.

The signature statement of the 2007 IPCC report may be paraphrased as this: “We are 90% confident that most of the warming in the past 50 years is due to humans.”

We are not told here that this assertion is based on computer model output, not direct observation. The simple fact is we don’t have thermometers marked with “this much is human caused” and “this much is natural.”

So, I would have written this conclusion as “Our climate models are incapable of reproducing the last 50 years of surface temperatures without a push from how we think greenhouse gasses influence the climate. Other processes may also account for much of this change.”

Professor Paul Reiter, Institut Pasteur; Paris states on the subject of scientific consensus:

Consensus is the stuff of politics, not of science. Science proceeds by observation, hypothesis and experiment. Professional scientists rarely draw firm conclusions from a single article, but consider its contribution in the context of other publications and their own experience, knowledge, and speculations. The complexity of this process, and the uncertainties involved, are a major obstacle to meaningful understanding of scientific issues by non-scientists.


  1. What makes you an expert on climate change? you work in telecommunications for gods sakes. I prefer to hear from the over 2000 CLIMATE SCIENTISTS who are working independently around the world. and if we don't do something about climate change and they are right, there will be NO economy or anything else to fight over because we won't have an environment to sustain human life! Are you willing to take that kind of risk? What oil company is paying you to blog? LOL

    1. What an interesting comment you make Jackie. Full of the usual array of emotionally charged, factually poor arguments that believers in climate change put forward as evidence of their position. If you had cared to read the above post you would have found that many of the claimed 2,500 scientists were in fact not climate scientists or indeed even scientists at all. Many were in fact activists from organisations such as WWF and Greenpeace or undergraduates who would write the desired way. If I can suggest you read Donna Laframboise's "The Delinquent Tennager Who Was Mistaken For The World's Top Climate Expert" then perhaps you would have a broader view of the issue than the narrow one you current express. Thank you for your input.

    2. I am surprised that you didn't try an drag out the old chestnut about ...98% of climate scientists agree that global warming is man made and is real, for it too was a fraud designed to create an image of certainty to the consensus argument put forward by believers such as yourself, Jackie. The reality is as follows:

      So where did that famous “consensus” claim that “98% of all scientists believe in global warming” come from? It originated from an endlessly reported 2009 American Geophysical Union (AGU) survey consisting of an intentionally brief two-minute, two question online survey sent to 10,257 earth scientists by two researchers at the University of Illinois. Of the about 3.000 who responded, 82% answered “yes” to the second question, which like the first, most people I know would also have agreed with.

      Then of those, only a small subset, just 77 who had been successful in getting more than half of their papers recently accepted by peer-reviewed climate science journals, were considered in their survey statistic. That “98% all scientists” referred to a laughably puny number of 75 of those 77 who answered “yes”.

      That anything-but-scientific survey asked two questions. The first: “When compared with pre-1800s levels, do you think that mean global temperatures have generally risen, fallen, or remained relatively constant?” Few would be expected to dispute this…the planet began thawing out of the “Little Ice Age” in the middle 19th century, predating the Industrial Revolution. (That was the coldest period since the last real Ice Age ended roughly 10,000 years ago.)

      The second question asked: “Do you think human activity is a significant contributing factor in changing mean global temperatures?” So what constitutes “significant”? Does “changing” include both cooling and warming… and for both “better” and “worse”? And which contributions…does this include land use changes, such as agriculture and deforestation?

      So once again, what is claimed and what is reality is very different.