Quirin Schiermeier has an article in the current issue of Nature on our recent workshop on disaster loss trends and climate change. The workshop executive summary can be found here and a PDF here. The article, unfortunately, has a few mistakes and is subject to misinterpretation.


1. The Nature article does not recognize that the workshop participants used the IPCC definition of “climate change” to mean a change irrespective of causes. At several points the author of the Nature article conflates “climate change” and “global warming” which is something we at the workshop were careful not to do. Here is the opening paragraph of the Nature story:

Insurance companies, acutely aware of the dramatic increase in losses caused by natural disasters in recent decades, have been convinced that global warming is partly to blame. Now their data seem to be persuading scientists, too. At a recent meeting of climate and insurance experts, delegates reached a cautious consensus: climate change is helping to drive the upward trend in catastrophes. . .

Delegates seem to have found the record persuasive. Their consensus statement, to be released on 8 June, says there is “evidence that changing patterns of extreme events are drivers for recent increases in global losses”.

Clearly climate change has played a role in driving recent increases in losses. On attribution to human causes see below.

2. The article does not distinguish my collaborator’s personal views from those of the workshop consensus, thereby creating room for confusion. Here is the relevant passage:

There was no agreement on how big a role global warming has played, however. “Because of issues related to data quality, it is still not possible to determine the portion of the increase in damages that might be attributed to climate change,” the workshop concluded.

“Dissent over the issue is clearly waning,” says Peter Höppe, head of Munich Re’s Geo Risks department, who co-chaired the workshop with Roger Pielke Jr, director of the University of Colorado’s Center of Science and Technology Policy Research. “Climate change may not be the dominant factor, but it has become clear that a relevant portion of damages can be attributed to global warming.”

The workshop consensus is worth repeating:

11. Because of issues related to data quality, the stochastic nature of extreme event impacts, length of time series, and various societal factors present in the disaster loss record, it is still not possible to determine the portion of the increase in damages that might be attributed to climate change due to GHG emissions

and

13. In the near future the quantitative link (attribution) of trends in storm and flood losses to climate changes related to GHG emissions is unlikely to be answered unequivocally.

3. Nature unfortunately trots out the worn “skeptic” label to describe my views:

Previously sceptical, Pielke says that he is now convinced that at least some of the increased losses can be blamed on climate: “Clearly, since 1970 climate change has shaped the disaster loss record.”

He adds a note of caution, however: “Disaster damage is not the place to look for early indications of climate change,” he says. “Policy advocates should exercise caution in using disaster losses to justify climate mitigation, lest they go beyond what science can support.”

I was accurately quoted, but my use of the term “climate change” was as we used it at the workshop. [Update- Upon checking I was misquoted! See comments. RP] I am increasingly convinced that since 1970 a portion of the increase in disaster losses is due to changes in climate, clearly, and largely due to US hurricanes. But it is less clear that such trends exist if the record dates to 1950 or 1920.

4. Nature cites GermanWatch as a group who has used attributed disaster losses to human-caused climate change, but does not mention that a representative of the group participated in the workshop and signed on to the workshop consensus.

Overall, I am disappointed with this story.