Martin Parry, Chair of IPCC AR4, working group 2, on 13 February 2010

I got a copy of this letter, which presumably was sent to Working Group II authors and others on 13. Februrary 2010 by the chair of Working Group II of  AR4, Prof Martin Parry. This part of the 4 Assessment report (AR4) of the IPCC has attracted significant criticism in the past. It seems that Martin Parry considers the critique inadquate.
When commenting on this, please pay attention to netiquette. I will not hesitate to delete inflammatory, insulting or otherwise stupid comments.


To WGII authors, co-chairs and vice-chairs

From Martin Parry:

Dear Colleagues:

I wanted to give you a personal view of the current media criticisms that have been made of the IPCC WG2 assessment and the IPCC response to these.

Firstly, in the current clamour it is easy to forget the big picture, which I think is this: That the WG2 volume represents a sound and reliable statement of our knowledge, and is the product of robust and rigorous assessment by you all.

However, you are probably perplexed, like me, at the way some apparently minor points can grab the headlines. Our tendency as scientists is to get on with our current work which now (3 or 4 years on from our 2007 assessment) is often unrelated to issues in the press. Yet the public is probably equally perplexed, and we can help them by continuing to be open about our workings and our conclusions. In this respect the IPCC has aimed to develop background information on each of the issues. Not all these are being posted on the IPCC website, but they are available from the IPCC Secretariat for the media and from the WG2 office to help authors in your reply to press questions. I am very grateful for Chris Field and his team taking the lead on preparing this information, with considerable help from Jean-Pascal van Ypersele.

If you can take the time to look at these ‘response statements’ you will see that the criticisms are generally unfounded and also marginal to the assessment. But they are partly based on a misunderstanding that we can all help to clear up: Some of the media have criticised us for using non-journal sources because these are not reviewed, but this a) wrongly assumes that IPCC assessment should not use non-journal literature (Annex 2 of the IPCC assessment procedures clearly spell out how they can and should be used), and b) mistakenly assumes that UN, government, agency and NGO reports are generally unreviewed. Many such reports are intensively reviewed, both internally and externally. Even if not peer-reviewed, there are reports that contain valuable information about experiences with adaptation, for example. You know that IPCC procedures ask that especially careful attention be given to the veracity of such sources because they can be variable in quality. It would therefore be helpful if, when asked about non-reviewed sources, you make clear what the IPCC assessment procedures are and how you followed them. The IPCC homepage now has a useful summary of these procedures.

Here is a summary of the response made to criticisms:

1. The IPCC has posted a notice on its website http://www.ipcc.ch/pdf/presentations/himalaya-statement-20january2010.pdf to the effect that assessment procedures should have been followed more carefully in the statement about the likely disappearance of Himalayan glaciers by 2035. The statement derived from evidence from an apparently reliable source who, I believe, was the chair of the Himalayan sub-group of the World Glacier Commission, but this evidence was not strong enough to support the level of confidence implied by the text.

2. IPCC authors have defended their statement in Chapter 1 that one study indicates an increase in economic losses due to disasters after normalizing for wealth and property while other studies do not. This rebuttal can also be found on the IPCC home page.
http://www.ipcc.ch/pdf/presentations/statement_25_01_2010.pdf

3. IPCC authors in Chapter 1 have defended their use of climbing records as part of the range of evidence of possible effects of changes in snow and ice cover on recreation. This source was not used as evidence for ice changes per se, which was a misunderstanding in the press comment. Their statement is available on request from the IPCC Secretariat and WG2 office.

4. Authors of the chapter on Latin America have demonstrated that their conclusion that ‘up to 40% of the Amazonian forests could react drastically to even a slight reduction in precipitation’ is based on peer-reviewed sources in their chapter, including information from the journal Nature. Their statement may be obtained from the IPCC Secretariat and WG2 office.

5. The chapter on Europe quotes 55% of the Netherlands as being below sea level, but there appear to be several definitions of this. The Dutch Ministry of Transport uses the figure 60% (which is below high water level during storms), while others use 30% which is below mean sea level. The statement may be obtained from the IPCC Secretariat and WG2 office.

6. The statement that in Africa ‘by 2020, in some countries, yields from rain-fed agriculture could be reduced by up to 50%’ relates to the combined effects of climate variability and climate change, as correctly reported in the chapter on Africa and in the WG2 TS and SPM. A similar qualifier should have been included in the SYR. The statement may be obtained from the IPCC Secretariat and WG2 office.

My conclusion from the above is that the criticisms have been marginal and very largely unfounded. I think you should take encouragement from this.

However, news can take a life of its own, and what began with a single unfortunate error over Himalayan glaciers has become a clamour without substance which many believe is being fed by critics and sceptics. Unfortunately the IPCC is not set up for rapid rebuttal of the kind the media now expect; and with good reason, because questions about science need careful investigation and a considered reply, not an immediate statement to the press. Thus, each of the queries raised has involved about a week of investigation and discussion by IPCC authors before a conclusion is published. This is why many colleagues feel our critics are having a ‘field day’ or ‘dream run’ and the press are not reflecting a balanced picture. But, is there any other way than for us to take our time and conduct a careful investigation of each query? We have to trust that in the long run common sense will prevail.

We can, however, all play a role in communicating with media to avoid unwarranted erosion of confidence in the IPCC. You should feel free to talk with the press to make the case for the broader picture, and encourage your non-IPCC colleagues to do likewise. As always, make clear at the outset whether you are speaking on the record and can be quoted, or off the record as background. I initially felt that I should leave comment to IPCC spokespersons who know the wider circumstances; and have been helping Chris Field and the authors develop the written responses. More recently I have felt I should give more press interviews (you’ll see a piece in Nature on line from 16th February).

I wish to repeat here, firstly, my thanks for your honest, solid and professional work and, secondly, my confidence in the ability of the IPCC to conduct rigorous and reliable assessments. Of course, our knowledge of climate change is always advancing and we should always be seeking ways of improving our assessments, but the WG2 AR4 assessment is a robust one. Let us make that clear to all who are willing to listen.

13 February 2010