In a diary a few weeks ago I indicated that the exaggeration of hurricane science, in the wake of the active 2005-2006 hurricane seasons and hurricane Katrina, didn't do harm to risk assessment and (re)insurance companies. I also indicated that science behind the 5-year projections of risk assessment companies have been shown to be flawed (and that, unsurprisingly, 5-year projections are horribly failing).
While commenting in said diary, I hit upon a feature that drew my interest: how much the world's largest reinsurance company just doesn't care about science, and continues to propagate nonsense, despite knowing better. You know, claims like these:
Except that increasing flood, windstorm and hurricane losses have not been attributed to global warming / climate change so far.
Meet Munich Re: the world's leading reinsurance company, based in Munich, Germany, and serial offender in communicating doom. This was the snippet that grabbed my attention:
First of, I do applaud companies speaking out for initiatives to curb anthropogenic greenhouse gas emissions, which Munich Re and other important companies in the reinsurance branch (like the competing Swiss Re) do prominently. Unfortunately, Munich Re seems to frequently suffer from cognitive dissonance between their PR department and their own considerably qualified science group. Let me explain what I mean with that.
Starting with tropical cyclones, that proud icon of climate change, first a backtrack to 2005, when two prominent publications gained wider traction in the public domain. Both articles were released briefly after hurricane Katrina had struck New Orleans, and many people on the world were wondering if climate change had anything to do with that catastrophe.
The Webster et al. (2005) article argued that there were appearing more tropical cyclones in the Atlantic Basin, in short, the frequency was increasing (but the same article also argued against a global increase). On top of that, the Nature paper by Emanuel that had been released shortly before, argued that particularly for the Atlantic Basin, hurricanes were becoming increasingly more violent, that is, an increasing intensity, beyond the scale of natural variation. All of that sounded indeed disconcerting, but the hurricane scientists were heavily divided over these announced results, particularly by how these scientists had gotten their results. Nevertheless, both papers became cornerstones for the conclusions of the IPCC 2007 report on tropical cyclones, summarising them as following:
While other basins do not show overall increases in activity,
While being perfect fodder for Munich Re's press releases, the papers exacerbated divisions in the hurricane science community, with a classic divide running between modellers and data scrutinizers. Yet, unlike the Climate Wars over temperature proxies, experts kept talking and discussing with each other. And the result? An authoritative, key paper in Nature Geosciences published early this year, written by hurricane experts encompassing several camps, including Emanuel. So what does it read?
Large amplitude fluctuations in the frequency and intensity of tropical cyclones greatly complicate both the detection of long-term trends and their attribution to rising levels of atmospheric greenhouse gases. Trend detection is further impeded by substantial limitations in the availability and quality of global historical records of tropical cyclones. Therefore, it remains uncertain whether past changes in tropical cyclone activity have exceeded the variability expected from natural causes.
Emphasis mine. That single sentence negates Webster et al. for the time being. How does it work out for Emanuel's paper?
The most significant cyclone intensity increases are found for the Atlantic Ocean basin, but the relative contributions to this increase from multidecadal variability (whether internal or aerosol forced) versus greenhouse-forced warming cannot yet be confidently determined.
And with one stroke, the IPCC chapter on tropical cyclones needs to be rewritten.
But wait! If we actually can't observe a global warming trend in tropical cyclones, how do we attribute a global warming signal to damage losses from Atlantic hurricanes - as Munich Re blithely announces? Well. We can't. And even before the recent Nature paper, damage losses from hurricanes in the Atlantic Basin had been analysed at least twice, with identical results:
Pielke et al. (2008):
Schmidt et al. (2009):
That last paper was actually written by scientists working for Munich Re... That's what I'd call cognitive dissonance - although the authors do stress that there is a higher chance climate change is playing a part in tropical cyclone losses. Except: it can't be shown.
Right, increasing hurricane damage for the USA can't be contributed just yet to climate change. Can happen. But USA is only a country. Doesn't say anything about the rest of the world! And I didn't even mention floods so far.
You know, I could next point everyone to this study on flood losses in Europe showing no correlation between increased flood damage and climate change, based on data amongst others from Munich Re but I think the point I wanted to make is clear by now.
All listed studies are prominent, solid science publications, all available in the public domain. I will post a diary the moment I find studies that conclusively show a linkage between climate change and catastrophe losses. Promise. Because, in all fairness, that there will be increasing (normalised) catastrophe losses with increasing global temperatures does look guaranteed - except that this is a long term prediction. But it's simply not the reality of today: in terms of major catastrophes losses, a climate change signal has not be attributed so far by scientific research. The subjects are complex, many factors contribute, the variability in the data has been too large so far to determine a trend.
Yet, incredibly convenient, unsubstantiated doom is sold by the world's leading company selling reinsurance. Whom would you believe?