Some of us have been waiting quite a while now, especially since the ‘road tour’ meant to present the Special Report on Managing the Risks of Extreme Events and Disasters to Advance Climate Change Adaptation starting in Oslo on January 24th this year. The summary for policymakers (SPM) was released already in 18 November 2011 (Kampala) and now the report is finally available (link).

People may have been a little annoyed that references last January were made to a report that was not yet available, and I hope that next time, the IPCC releases the SPM together with the main report. This is apparently a common way of doing things at the IPCC/UN/UNEP level, and I think the common opinion in the science community is that we wish they wouldn’t do it that way.

Perhaps this order of releasing the report was the reason for some disappointing comments I overheard from the people responsible for the ‘road tour’ about a lack of media interest (why would media they come when the big points already were old news?). However, I guess that may not have been a bad thing, since one could get the impression of lacking coordination between different presenters, as some slides were presented several times (which some people may find a bit annoying), perhaps giving a wrong impression of a limited range of new results.

I think the SREX report really provides a useful overview of the state of our knowledge about climate extremes. I’m also sure that a many scholars will scrutinize the report and check its account of all various aspects about extreme events and severe consequences. I already wrote my first comment about the storms when the summary for policy-makers came out.

My first response to the released main report was to turn the pages of the report to topics for which I have particular interests. We have already written several posts here on RealCimate about the type of information we can glean from the statistics of record-breaking events (for instance here, here, and here), and I wonder whether this notion seems to be a bit difficult to grasp for some scholars (here and here). It is a new way of looking at the data, and I notice that even the SRES report (p. 125) makes a statement that puzzles me:

One approach is to count the number of record-breaking events in a variable and to examine such a count for any trend. However, one would still face the problem of what to do if, for instance, hot extremes are setting new records, while cold extremes are not occurring as frequently as in the past. In such a case, counting the number of records might not indicate whether the climate was becoming more or less extreme, rather just whether there was a shift in the mean climate.

I think that this passage reveals a misunderstanding about the use of the record-breaking statistics, and how the number of records can be used to see whether the extreme tails of a statistical distribution is stretched over time. We can rephrase this as testing whether the data are independent and identically distributed (IID), or apply what we call an ‘IID-test’ (link to the Benestad_2008EO410002; an R-package for iid-tests are available here).

Hopefully, this way of looking at extremes will be more appreciated in the upcoming AR5 report.