A Reexamination of Climate Change Issues

Normalized Hurricane Damage in the United States: 1925 - 1995

 November 18, 2009



This article contains excerpts from a study by Roger Pielke and Christopher Landsea which “normalizes” the trends of the costs of hurricane damage over the past century.  The report shows that after corrections have been factored in there is no link between global warming and the amount of damage caused by storm intensity.

View the original study


"..  More appropriate trends in the United States hurricane damages can be calculated when a normalization of the damages are done to take into account inflation, and changes in coastal population and wealth."


"With this normalization, the trend of increasing damage amounts in recent decades disappears.  Instead, substantial multidecadal variations in normalized damages are observed: the 1970s and 1980s actually incurred less damages than in the preceding few decades.  Only during the early 1990s does damage approach the high level of impact seen back in the 1940s through the 1960s, showing that what has been observed recently is not unprecedented.  Over the long-term, the average annual impact of damages in the continental United States is about $4.8 billion (1995 $) - substantially more than previous estimates.  Of these damages, over 83% are accounted for by the intense hurricanes (Saffir-Simpson 3, 4 and 5), yet these make up only 21% of the U.S.-landfalling tropical cyclones."





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"The normalized data indicate clearly that the United States has been fortunate in recent decades with regard to storm losses as compared with earlier decades.  The data further refute recent claims that the rapid increase in non-normalized damages are due to climatic changes (cf. Changnon et al. 1997).  When inflation, wealth, and population changes are taken into account, instead of increases, normalized damages actually decreased in the 1970s and 1980s.  The 1990s, so far, are more akin to the normalized damages that occurred during the 1940s and 1960s, and are by no means unprecedented.  Thus, caution is urged in interpreting statements regarding the increasing number of "billion-dollar losses" or other such measures (e.g., Flavin 1994).  With respect to hurricanes, the clearest evidence for increases in losses is changes in society, not in climate fluctuations.  Indeed, a climate signal is present in the normalized data, and this is of decreased impacts in recent decades."