02 November 2009

Normalized Flood Losses in Europe: 1970-2006

J. I. Barredo of the European Commission published an interesting paper earlier this year titled, "Normalized Flood Losses in Europe: 1970-2006" (PDF) in the open access journal Natural hazards and Earth System Sciences of the EGU. The study looks at a relatively short period, 37 years, but its findings are interesting nonetheless. Here are a few excerpts (emphasis added):
Following the conceptual approach of previous studies, we normalised flood losses by considering the effects of changes in population, wealth, and inflation at the country level. Furthermore, we removed inter-country price differences by adjusting the losses for purchasing power parities (PPP). We assessed normalised flood losses in 31 European countries. These include the member states of the European Union, Norway, Switzerland, Croatia, and the Former Yugoslav Republic of Macedonia.

Results show no detectable sign of human-induced climate change in normalised flood losses in Europe. The observed increase in the original flood losses is mostly driven by societal factors.
And also:
Despite the existing evidence (see Table 1) of changes in temperature and precipitation in Europe (Alcamo et al., 2007; Rosenzweig et al., 2007; Trenberth et al., 2007) there is no conclusive evidence for a climate-related trend for hydrologic floods either on a continental or a regional scale in Europe (Glaser and Stangl, 2003; Mudelsee et al., 2003; Lindstr¨om and Bergstr¨om, 2004; Kundzewicz et al., 2005, 2007; Macklin and Rumsby, 2007). This supports the hypothesis that a positive trend in the increase of flood losses should be attributed to societal shifts in the exposed areas.
The paper concludes:
These results indicate that changes in population, inflation and per capita real wealth are the main factors contributing to the increase of the original raw losses. After filtering their influence there remains no evident signal suggesting any influence of anthropogenic climate change on the trend of flood losses in Europe during the assessed period.
Studies of disasters around the world are unambiguous and uncontested: Increasing damage over recent decades can be explained entirely by societal factors and there is no evidence to support the hypothesis that greenhouse-gas driven climate change has led to increasing disasters. The standard disclaimer applies -- this does not mean that action to address accumulating greenhouse gases does not make sense; as I've stated on many occasions, it does. What it does mean is that efforts to point to contemporary disasters as a basis for action on energy policies are misleading at best.

6 comments:

Andrew said...

"this does not mean that action to address accumulating greenhouse gases does not make sense; as I've stated on many occasions, it does."

On what basis? What is it that justifies the "action" if there are no consequences of "inaction"? Or do you believe there are consequences and what sort of consequences then? Because I suspect that many problems you believe will arise are just issue you haven't worked on.

Lessee-can't be floods. Can't be hurricanes. Can't be tornadoes. I don't think you are dumb enough to think heat related mortality will be an issue. Is it sea level that worries you? I don't see how the rather small rises predicted for the future can be taken as particularly troubling. I don't get it, how do you justify "action"?

glacierchange said...

I do not find Barredo Figure 2 and 3 convincing as to no trend in losses. Figure 2 illustrates that more years have significant events in the last two decades. Figure 3 indicates that since 1995 losses have been above the mean line shown and before 1980 losses were below. Looks like a trend, sure the significance can be quantified as not as important, but it is there.
Hoppe and Grimm from Munich Re have suggested that climate change does have a role. http://www.springerlink.com/content/u35366232u3321v7/
Munich Re itself in examining the issue notes on page 6 some of the observations of intense storm events in several European nations. These undoubtedly lead to more flooding and more flood losses.
http://www.munichre.com/publications/302-05482_en.pdf

Roger Pielke, Jr. said...

-2-glacierchange

I think that the following statement of the paper is probably where you might focus, rather than looking at wiggles in short-term data:

"... there is no conclusive evidence for a climate-related trend for hydrologic floods either on a continental or a regional scale in Europe (Glaser and Stangl, 2003; Mudelsee et al., 2003; Lindstr¨om and Bergstr¨om, 2004; Kundzewicz et al., 2005, 2007; Macklin and Rumsby, 2007)"

Laurens said...

Thanks, glacierchange, for the link to Höppe and Grimm, did not know that paper. They however do not go any further than *suggesting* that there might be a signal. Also their recent paper on hurricane losses has no conclusive proof: http://dx.doi.org/10.1016/j.eiar.2009.03.003

As Roger points out, there is no evidence for increase in flooding, so would there be a signal in losses then?

jgdes said...

This is the nub of the problem glacierchange: Anyone can "suggest" that anything is affected by climate change without proof or censure even when the data in their own paper demonstrates the exact opposite. There seem to be no reviewers willing to say to Hoppe, for example; "if your own data shows no trend over 50 years then your suggestions are obviously wrong."

Vinny Burgoo said...

Barredo's study contradicts the European Commission's regular report _1.2 Natural disasters linked to climate change_ (PDF available online), which claims that floods 'linked to climate change' have increased considerably in Europe since the 1980s and that in 2000-2008 they represented '50% of natural disaster linked to climate change, caused 548 deaths, 1.4 million affected and economic damage for around US$ 48 billion damage'. The report is compiled by picking more-or-less random categories of disaster in CRED's EM-DAT database and ascribing all disasters in those categories to climate change - a crazy approach.

The authors (Unit ENV.A.3: Civil Protection, if you want to get in touch) might quibble that they say only that the disasters are 'linked to climate change', but if 'linked to' doesn't mean 'caused wholly or partly by' then what are they talking about? Linked by whom? The man on the street? Certainly not CRED.

They might also point to the paragraph at the end of the report conceding that 'population vulnerabilities' are also implicated in disaster trends, but that only makes things worse. It shows that the authors know that their numbers are meaningless: 'Hamsters caused 864 traffic accidents in 2007 (no, they didn't).'

I e-mailed the Commission about this in August and had a friendly reply saying that the relevant people were on holiday. A while later, another friendly note: they were all busy preparing for the Copenhagen climate summit. Then silence. Finally, some time in October the report was modified: someone added a coloured version of the chart.

I wonder which disaster analysis Europe's leaders will take to Copenhagen: the convenient one-page report card with its pretty coloured chart, little red frowny face (no, really) and wholly bogus numbers or Barredo's, er, slightly more rigorous effort. Hmmm. Tricky one.

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