John Woods, Director of Friends of the Earth Northern Ireland, asserts in his September 11 opinion piece: "The UN's Intergovernmental Panel on Climate Change, which draws together the work of over 2,500 scientists, has concluded that most of the increase in global temperatures since the mid-20th century is very likely due to the increase in greenhouse gases from human activity."
This is a highly misleading statement.
Here's the real situation.
The UN's Intergovernmental Panel on Climate Change (IPCC) puts out "assessment reports" every five years or so, its latest being the much cited 2007 Fourth Assessment Report.
Each assessment report covers the work of three working groups.
The approximately 1,000-page Working Group I (WG I) report, entitled The Physical Science Basis, contains the assertion made by Mr Woods above; its exact wording is found in Chapter 9, Understanding and Attributing Climate Change, and is the following: "Greenhouse gas forcing has very likely caused most of the observed global warming over the last 50 years."
So how many of the 2,500 scientists who reviewed parts of the complete IPCC report actually reviewed this statement?
Very few indeed.
We know this because, for the first time ever in 2007, the UN released on the Web scientist reviewers' comments concerning the drafts of the WG I report and the IPCC editors' responses.
An examination of reviewers' comments on the last draft of the WG I report before final report assembly (i.e. the Second Order Revision) 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. What we find is that a grand total of 62 reviewers commented on the critical Chapter 9; in other words, 2.5 per cent of the total 2,500 participants.
Of the comments received from the 62 reviewers of this critical chapter, almost 60 per cent of them were rejected by IPCC editors.
And of the 62 expert reviewers of this chapter, 55 had serious vested interests (being employees of governments that already had decided on the outcome, for example), leaving only seven expert reviewers who appear impartial.
Two of these seven had interesting comments about the IPCC Chapter 9 statement that Mr Woods implies 2,500 IPCC reviewers support:
Dr Ross McKitrick of the University of Guelph, Canada said, "A categorical summary statement like this is not supported by the evidence in the IPCC WG I report.
The full article contains 419 words and appears in News Letter newspaper.
