A few days ago, Jochem Marotzke, an IPCC Coordinating Lead Author and, according to Der Spiegel, “president of the German Climate Consortium and Germany’s top scientific representative in Stockholm”, was praised (e.g. Judy Curry here) for his promise that the IPCC would address the global warming hiatus “head on” despite pressures from green factions in government ministries and for his declaration that “climate researchers have an obligation not to environmental policy but to the truth”.

However, it turned out that Marotzke’s promise was merely another trick. Worse, it turns out that Marotzke already knew that the report would not properly deal with the hiatus – which, in a revealing interview, Marotzke blamed on an ” oversight” (h/t to Judy Curry here). Worse, it turns out that IPCC authors were themselves complicit during the plenary session in causing information about the discrepancy between models and observations to be withheld from the SPM, as shown by thus far undiscussed minutes of the IPCC plenary session.

Just before the release of the IPCC SPM Judy Curry drew attention to Marotzke’s interview with Der Spiegel (Sep 23, 2013) prior to release of the SPM on Sep 27, 2013, the interview in which Marotzke promised that IPCC would deal “head on” with the hiatus.

In my post here, I pointed to an ad hoc and desperately cobbled box (Box 9.2) in the Government Draft as IPCC’s belated and completely unsatisfactory effort to deal with the Pause, pointing out that the IPCC’s ability to assess the Pause from peer-reviewed literature was compromised because of accumulated failure both by IPCC and its community:

But the problem not arise “last week”. While the issue has only recently become acute, it has become acute because of accumulating failure during the AR5 assessment process, including errors and misrepresentations by IPCC in the assessments sent out for external review; the almost total failure of the academic climate community to address the discrepancy; gatekeeping by fellow-traveling journal editors that suppressed criticism of the defects in the limited academic literature on the topic.

In a post entitled How the IPCC Forgot to Mention the Pause, Judy now draws attention to an article in the Christian Science Monitor (Sep 27, 2013) containing an interview with Marotzke in which he tells an entirely different story than the one told to Der Spiegel.

Thomas Stocker, WG1 Co-Chair and Climategate correspondent, who was also interviewed, conceded my observation that there was negligible peer-reviewed literature on the topic as follows (but was not asked about the role of IPCC-sympathizing journal editors in rejecting submissions):

the group, which relies on studies published in peer-reviewed journals for its overviews, didn’t have much to go on, acknowledges Working Group 1’s co-chairman, Dr. Stocker. “I’m afraid to say there is not a lot of published literature that allows us to delve deeper into the required depth of this emerging scientific question,” he says,

Marotzke blamed IPCC’s failure to adequately address the pause as an “oversight”, rather than a deliberate intent to mislead, “explaining” to the reporter that authors in each chapter thought that someone else was handling the problem. Here is an extended quote:

Scientists in the first working group also have tried to tackle the issue of the pause in surface warming that has marked the past 15 years – although they came to the issue a bit late in the process, acknowledges Jochem Marotzke, director of the Max Planck Institute for Meteorology in Hamburg and a lead author on one of the main volume’s chapters. Some 200 authors involved in the first report met in Hobart, Australia, in January for a final gathering to hammer out wording, in light of reviews they had received on a previous draft. “We got quite a few review comments on various chapters saying: What’s going on here? We need to assess what we know” about the hiatus, he said during a briefing Friday morning. He attributed the oversight to a tendency of each group working on each of the 14 chapters to rely on some other chapter to deal with the issue. And anyone who was thinking about it at all thought some other chapter should handle the issue.

Here one has to watch the pea. Marotzke’s excuse – lack of coordination among authors of various chapter – might have been valid for the Zero Order Draft, but not for the next two drafts. The “Second Order Draft” discussed at Hobart was (at least) the third draft distributed to Lead Authors. The “oversight” observed in Hobart in January 2013 could just as easily been identified in the Zero Order Draft or the First Order Draft. The problem was not a single incident, but accumulating failure.

Making matters worse were interventions of IPCC Coordinating Lead Authors (including presumably Marotzke and Stocker) in the plenary session (see here h/t commenter at Judy Curry’s), where the CLAs actively fought against disclosure of the inconsistency between models and observations in the Summary for Policy-makers – an incident that I plan to report on separately:

In the explanation of the observed reduction in the surface warming trend over the period 1998-2012, Saudi Arabia strongly urged incorporating language from the Technical Summary on models overestimating the warming trend. The CLAs advised against including this statement in the SPM, noting that: the research is currently inconclusive; overestimation of the models is too small to explain the overall effect and not statistically significant; and it is difficult to pinpoint the role of changes in radiative forcing in causing the reduced warming trend, with Co-Chair Stocker referring to this issue as an “emerging science topic.”

While I will discuss this incident separately, the claim that the effect is “not statistically significant” is untrue.



