IPCC denies newspaper claim that it overstated costs of natural disasters

UN body rebutts Sunday Times allegation that it exaggerated link between costs of natural disasters and climate change
James Randerson
guardian.co.uk, Tuesday 26 January 2010 16.48 GMT
The UN body that summarises climate science for governments has condemned as "misleading and baseless" claims that it overstated the effect of global warming on natural disasters.
A newspaper report alleged a section in the Intergovernmental Panel on Climate Change's 2007 report incorrectly stated that the cost of natural disasters had risen gradually since 1970 due to climate change. Yesterday, the IPCC issued a statement saying the Sunday Times report was wrong on "two key points".
The IPCC, and its head Rajendra Pachauri, are currently under fire following the inclusion in the same report erroneous of a claim that Himalayan glaciers could melt completely by 2035. The statement was not based on peer reviewed data and the true figure for Himalayan glacier melt is thought to be closer to 300 years. The IPCC has admitted the claim was incorrect, but all senior scientists emphasise that glaciers are melting at historically high rates and that the role of human activity in causing global warming remains very likely. Pachauri said yesterday: "I am not going to stand down, I am going to stand up."
Bob Ward, policy director of the Grantham Research Institute on Climate Change at the London School of Economics, said the row over natural disasters is neither a blunder or a new criticism of the report. He said the row is the result of criticisms that date back to 2006 that are being raked over because the IPCC's procedures for reviewing scientific work is currently under the spotlight.
The controversy centres on why the cost of repairs after hurricanes, floods and other natural disasters, has risen from $75.5bn in the 1960s to $659.9bn in the 1990s. Much of the increase is because economic growth has given people more to lose, but some could be due to more destructive natural disasters as the Earth warms. The infrequency of natural disasters coupled with the short period of data also means that a small number of events in a rich region of the world could have a large impact on the figures.
The IPCC's report said that one study by Dr Robert Muir-Wood had identified a "small statistically significant trend" of annual catastrophe losses increasing by 2% a year since 1970, after economic growth had been taken into account. This claim is under attack because the original finding was presented at a scientific workshop in 2006 and was not peer-reviewed. When it was peer reviewed and subsequently published the authors reached the same conclusion but noted the statistical trend disappears when the particularly heavy 2004/05 hurricane season was omitted from the data.
In its rebuttal, the IPCC says its report made clear other studies disagreed with the Muir-Wood finding and that it provided a "balanced treatment of a complicated and important issue." The statement continues, "It clearly makes the point that one study detected an increase in economic losses, corrected for values at risk, but that other studies have not detected such a trend...In writing, reviewing, and editing this section, IPCC procedures were carefully followed to produce the policy-relevant assessment that is the IPCC mandate." The IPCC report also refers to three other studies by Professor Roger Pielke Jr of the University of Colorado and colleagues. Ward said that Pielke has criticised both the IPCC report and the Stern review - the influential report on climate change by the economist Lord Stern - several times on his blog since 2006 for citing the Muir-Wood study.
But even if the 2% a year trend is not correct, Pielke's own data suggest there is cause for alarm, said Ward. "He is right that an increase in the number of valuable properties in high-risk areas is overwhelmingly the cause of increased financial losses from extreme weather events over the past few decades," he said. "That in itself is a worrying conclusion given that climate change is expected to lead to changes in the occurrence and severity of such events."