Wetenschap - 9 september 2010

Leemans has his work cut out with IPCC

The climate panel IPCC must go about its climate predictions more thoroughly, the Inter Academy Council (IAC) has advised. ‘This report has serious repercussions for me’, says Wageningen professor of Environmental Systems Analysis Rik Leemans.

Leemans and his Wageningen Colleague Paul Kabat have both been designated review editor for the following IPCC report, both having contributed to earlier reports. Leemans: 'The evaluation process goes like this: the authors review all the scientific literature on the causes and effects of climate change and the measures that could be taken against them. To this end they trawl through thousands of scientific articles and use data from institutes such as the KNMI, the FAO and the World Bank. The authors summarize all those articles in a text of ten thousand words. The first draft goes to fellow-scientists for comments. Five pages of comments come back for every page of text. As review editor I have to make sure the comments are processed in a transparent way and that the summaries are consistent with the texts they are about. We also have to check all statements thoroughly: are they really based on scientific articles? That takes more time.'

Things can go wrong during this process, so the IAC has advised the IPCC to stick more rigidly to procedures and explains its conclusions about the climate better. Leemans: 'So it is not a matter of mistakes: the science is beyond dispute. By now the suspected mistakes in IPCC reports have been investigated twelve times, and every time is turns out the suspicions are unfounded. What does happen is that the conclusions in the climate report are not always traceable. As editors we can help out with that too. I am satisfied with the IAC's report, which contains well-considered advice.'
Divergent opinions
The review editors of the IPCC should also assess better whether divergent opinions and controversies are adequately reflected in the reports, advises the IAC. 'There is certainly room for improvement to the work process', responds Leemans. 'The procedures are twenty years old and it is time they were updated. The IPCC office is staffed by just three people and has responded most inadequately to criticism. That will indeed have to be done more professionally.
'Every extra check will be very useful, but it will take time. The total process of arriving at an IPCC report costs well over 150 million euros in working hours by hundreds of scientists. They are still doing it on a voluntary basis. I put a lot of time into the IPCC work and Wageningen University is paying my salary for that.'