No Significant Trend in Extreme Weather Events

Published April 11, 2011

Eric Neumayer and Fabian Barthel, researchers with the London School of Economics Department of Geography and Environment, have published a paper in the peer-reviewed journal Global Environmental Change looking into the question, “Has economic damage from natural disasters increased over time?” Noting there was only one study of trends in economic losses at the global level which, moreover, used a database assembled from ad hoc sources of “very varied quality,” Neumayer and Barthel conducted a global analysis using a database of more uniform quality compiled by the reinsurance company MunichRe for 1990-2008.

The researchers also undertook separate analyses for developed countries, developing countries, the United States and Canada (as one unit), Western Europe, Latin America and the Caribbean, and South and East Asia.

Many Events, Regions Studied
The researchers used two different methods of normalizing economic losses from natural disasters to look for evidence of trends in economic losses from (a) all natural disasters and (b) all weather-related disasters. They also examined loss trends from convective weather events (flash floods, hailstorms, tempest storms, tornados, and lightning) in the United States and Western Europe, and from hurricanes in the United States and the Caribbean. They also examined temporal trends in the number of disasters in the database.

No Significant Trend
The researchers found no significant upward trend in normalized economic losses for either all natural disasters or weather related disasters regardless of which normalization method is used. This was true at the global level, for developed and developing countries, and for the specific regions examined.

Similarly, they found no trends in normalized losses for convective events or hurricanes. Finally, they report there is no method of determining whether the lack of trend is due to adaptive measures or to changes in the intensities of the weather-related events.

In sum, this paper does not bear out claims that global warming will intensify damages from extreme weather events. It reaffirms the results of several other studies that have looked at loss trends under a variety of extreme weather events for specific areas/regions, finding any increasing trend disappears once population or increased wealth is accounted for.

Craig D. Idso, Ph.D. ([email protected]) is lead author of Climate Change Reconsidered, published by the Nongovernmental International Panel on Climate Change (NIPCC). An earlier version of this article appeared on the NIPCC Web site. Subscriptions to the NIPCC email distribution list are free of charge and can be ordered at

Internet Info:

“Normalizing economic loss from natural disasters: A global analysis”: