Sunday, September 5, 2010

IAC Report: Statements on TV

Controversial statements concerning the IAC report on German TV by Hans von Storch and Ottmar Edenhofer (4min, in German). Including a fine differentiation by Hans von Storch: The task of the IPCC is not to declare the truth about climate change, but the truth about the knowledge on climate change.


Richard Tol said...

The first remark by Edenhofer is a lie. Edenhofer was a lead author in AR4 WG3. That chapter does not reflect the literature. Papers that were at odds with the IPCC authors' viewpoints were omitted or cited incorrectly.

Reiner Grundmann said...

Did Edenhofer say that the Himalaya statement (glaciers gone by 2035)could have been backed up by peer-reviewed literature?

Georg Hoffmann said...

No. He said it was not necessary to use gray and wrong literature. Better use available scientific literature which of course never said something like 2035.


"Edenhofer is a lier. Rahmstorf is an idot."

I am sure you have near infinite understanding for the climategate letters.

Richard Tol said...

Edenhofer is well aware of this:

He had a response on his website for a while, but Google cannot find it now.

plazamoyua said...

It is very different

- The first remark by Edenhofer is a lie


- "Edenhofer is a lier. Rahmstorf is an idot."

I am sure you have near infinite understanding for the climategate letters.

The later is name calling, the former, absolutely not.

sil_beck said...

I am unhappy how the discussion was closed down (perhaps due to the media format and respective time constraints).
I would like to come back to the line of argumentation as opened by the IAC report:
• First, the “IPCC gates” are not simply caused by the use of non-peer-reviewed literature as suggested by the ZDF report but by the insufficient evaluation of non-peer-reviewed literature and thus a lack of quality control.
• Second, the ZDF report suggested the simple solution that only peer-reviewed literature has to be used in IPCC assessments. This solution may work for Working group I but it will really constrain the assessments of Working Groups II and III
“that rely more heavily on non-peer-reviewed literature (sometimes called gray literature) and involve a smaller and more diverse set of experts who may have less experience working on large international projects” (IAC 2010: p. 9).
Moreover, governments are often interested in topics for which there is little peer-reviewed scientific and technical literature, such as the costs of adaptation. Last but not least, it will also contribute to marginalize the expertise for all three Working Groups outside developed countries.
In order to maintain the political relevance and legitimacy of IPCC reports, the question thus is not whether or not to use “gray” literature but how to strengthen procedures for the use of the so-called ‘gray literature’. The IAC recommended:
“The IPCC should strengthen and enforce its procedure for the use of unpublished and non-peer-reviewed literature, including providing more specific guidance on how to evaluate such information, adding guidelines on what types of literature are unacceptable, and ensuring that unpublished and non-peer-reviewed literature is appropriately flagged in the report” (IAC 2010: p. 20).
According to this view, the relevant questions are how these procedures may look like and how they can consistently implemented and efficiently enforced …

Richard Tol said...

I think we should take a step back. Is it true that the IPCC only uses gray literature when it has too?

The effect of climate policy on employment is discussed in Chapter 11, WG3, AR4. I guess we all agree that this topic is relevant to policy. The IPCC cites six studies, one of which was peer-reviewed (and misquoted, by the way). Patuelli et al. published a meta-analysis of the literature on this subject, citing a long list of peer-reviewed papers.


Chapter 7 cites two papers on the impact of climate change on natural resource intensive industries. One is a press release, the other a peer-reviewed paper. Neither is on topic. And again there is a substantive and academic literature out there.

The IPCC should use gray literature where appropriate, but it should first and foremost do a proper survey of the literature.

sil_beck said...

Thank you, Richard, for providing an excellent example how the IPCC processes work in practice.
What do you think of the IAC problem diagnosis and its recommendations?
• The IAC framed it as a question of compliance, namely that IPCC authors do not follow IPCC procedures, in part because the procedures are vague (Diagnosis).
• Clearer guidelines (on the nature of acceptable unpublished or non-peer-reviewed sources) and stronger mechanisms for enforcing them are needed (Need to act).
• Enforcement could perhaps be a job of the Review Editors, building on their role of ensuring that such literature is selected appropriately and used consistently in the report (Solution).
Are these procedural solutions (quality control through review processes) effective and robust enough to address the problem(s) at stake?

Richard Tol said...

That is of course not all that the IAC said.

I agree that the guidelines and vague and poorly enforced. However, the root problem is the selection of people -- and the IAC tiptoed around that.

In AR5, the experience is that people who wanted to put the IPCC on their CV but not do anything much, volunteered to be review editors. Hardly the enforcer types that the IAC (righly) calls for.

Marcel Severijnen said...

Hans von Storch: "The task of the IPCC is not to declare the truth about climate change, but the truth about the knowledge on climate change". And that knowledge is filled with uncertainties and facts different from common opinions about climate change. Jeroen van der Sluijs, co-author of the well received study of the Dutch Rathenau Institute "Room for Climate Debate: perspectives on the interaction between climate politics, science and the media" (
reported here on Klimazwiebel on August 10 2010 (, is an expert on uncertainty. He was one of the first to point to the overselling of certainties in the climate change debate and warned in an early stage for the loss of trust, of which we have been witnesses.

“…the truth about the knowledge on climate change” implies to my opinion the recognition of fundamental uncertainty inherent to the future itself. I agree with the following citation of another scientist, Marjolein van Asselt, Councillor of the Scientific Council for Governement Policy (WRR), professor Risk Governance at Maastricht University. She wrote an article in the journal NRC of September 2 titled: ”IPCC heeft bijgedragen aan waarheidsillusie à la Gore”.

“The problem is not, as the IAC suggests that the IPCC should have better stated what is certain or not. The IPCC has failed to emphasize that her core business - forecasting the future - is inherently uncertain. And that IPCC is doing its best to translate what scientists are trying to understand of the current climate into what the future might be. And that it's for politics to determine whether they take such scientifically informed vision of the future seriously.” (my translation)

At 27 september the WRR will publish a study “Studying the future with policy“ which will be presented by Professor van Asselt. Her NRC article was based on this study.(

Marcel Severijnen said...

"Are these procedural solutions (quality control through review processes) effective and robust enough to address the problem(s) at stake?"

No that's not enough. As I wrote before ( comment 1 and 9) review processes are part of quality control, they can support a quality management system (QMS). But then a solid QMS should be installed, securing all crucial procedures, certainly including selecting adequate people.
It's not enough to attract highly valued professionals, who are apt to employ all their creative capacity, while ignoring simple rules and procedures of the organisation, because they feel limited by those rules. Most professionals are not familiar with limiting rules and procedures in their jobs, they should be left free to maximize their output as they put it, they simply don't like rules like everyone. In my experience professionals must be kept to rules in a strict way, and introducing a QMS has proven to be a robust way to handle this problem. And once a QMS has been installed, even professionals will feel the benefits of the system and adapt to it. Review processes are an excellent manner to check whether our dear professionals obey the rules, which they won't being humans too.....And a QMS offers tools to correct deviations of procedures, thereby closing quality control circles.