Sunday, May 31, 2009

Lies, damned lies, statistics and 300,000 dead people

I'd have to say that I am completely unsurprised that that incompetent fraud Kofi Annan is behind this absurd claim, ie that climate change is killing 315,000 people a year.
Here we have another example of the adage that there are "lies, damned lies and statistics."
It of course reemphasises a critical point - do not accept at face value claims made in studies without first checking the methods used to arrive at their results and the assumptions that underpin them.
And in this case, the assumptions are as dodgy as hell.
Even stranger, the private company that did the report for the UN, (the Geo-Risks group in Munich Re), was arguing only a few months ago that it was not possible to distinguish deaths that could be attributed to climate change from the general statistical noise relating extreme weather events etc!
But I suspect Munich Re delivers what its customers are seeking.
Roger A. Pielke Jr, a political scientist at the University of Colorado, Boulder, who studies disaster trends said in The New York Times that the report was "a methodological embarrassment."
As he observes here, in a longer and more considered response to the report, it relied upon a "cooked up comparison between earthquakes and weather related disasters."
Here is the bit where he talks directly about the problems with the method used:
On p. 84 the GHF report itself says:
However, there is not yet any widely accepted global estimate of the share of weather related disasters that are attributable to climate change.
One would think that would be the end of the story. However, to fill in for the fact that there is no accepted estimate, the report conjures up a number using an approach that is grounded in neither logic, science, or common sense.

2. Specifically, to get around the fact that there has been no attribution of the relationship of GHG emissions and disasters, this report engages in a very strange comparison of earthquake and weather disasters in 1980 and 2005. The first question that comes to mind is, why? They are comparing phenomena with many “moving parts” over a short time frame, and attributing 100% of the resulting difference to human-caused climate change. This boggles the mind. The IPCC itself says that 30 years are needed for the detection of changes in the climate system, and this time frame does not even reach that threshold. More to the point earthquakes and weather events do not have the same variability and earthquake disasters affect only a small part of the total inhabited area of the earth, whereas weather disasters occur much more widely. The assumption that weather disasters should track earthquake disasters is flawed from the outset for both geophysical and socio-economic reasons.

An alternative, more scientifically robust approach would be to look specifically at weather-related disasters, and consider the role of socio-economic changes, and to the extent possible, try to remove that signal and see what trends remain. When that has been done, in every case (US floods, hurricanes, Australia, India TCs, Latin America and elsewhere, all in the peer-reviewed literature) there is not a remaining signal of increasing disasters. In other words, the increase in disasters observed worldwide can be entirely attributed to socio-economic changes. This is what has been extensively documented in the peer reviewed literature, and yet — none of this literature is cited in this report. None of it! Instead they rely on this cooked up comparison between earthquakes and weather related disasters.

(Consider also that in no continental location has there been an observed increase in tropical cyclone landfalls, and yet this accounts for almost all of the windstorm disasters cited in the report. The increase must therefore be due to factors other than geophysical changes. This fact renders the comparison with earthquakes even more meaningless).

Munich Re’s own peer-reviewed work supports the fact that socio-economic factors can explain the entire increase in global disasters in recent decades.

Consider that in 2005 there were 11 earthquakes magnitude 7 or higher and in 1980 there were 14. by contrast, 1980 was a quiet weather year, and 2005 was very active, and included Katrina.


3. The report cites and undates the Stern Review Report estimates of disaster losses, however, in a peer-reviewed paper I showed that these estimates were off by an order of magnitude and relied on a similar sort of statistical gamesmanship to develop its results (and of course this critique was ignored):

Pielke, Jr., R. A., 2007. Mistreatment of the economic impacts of extreme events in the Stern Review Report on the Economics of Climate Change,
Global Environmental Change, 17:302-310. (PDF)

This report is an embarrassment to the GHF and to those who have put their names on it as representing a scientifically robust analysis. It is not even close.

To finish I'll raise yet again this question - if the alarmists' case is so strong, then why do they need to constantly exaggerate and over-hype things?

Posted via email from Garth's posterous

No comments: