SIR — 

It is fascinating how myths persist once established in popular culture and how they are even repeated in the Economist.  Regardless of your enviornmental orientation or your belief in anthropogenic global warming, Hurricane Katrina was not, at you say, an extreme weather event, but an ordinary category 3 hurricane (the maximum strength hurricane is a category 5).  The devastation it wrought was not so much due to its strength, but that it hit an ill-prepared area some of which was below sea level and which was protected by levees that were not properly maintained and were breached.  Hurricane Katrina, responsible for approximately 1,200 deaths, was not even the most devastating storm in modern history.  That title belongs to the category 4 Galveston Hurricane of 1900 which was responsible for an estimated 8,000 deaths.  The next most devastating hurricane was the San Felipe-Okeechobee Hurricane of 1928, which was the fourth strongest hurricane on record to hit the US mainland (a candidate to be designated an extreme weather event) and was responsible for 1,836 deaths in Florida when Florida had far fewer people than it has now.

While 2006 was unusual in that no hurricanes hit the US, 2007 is currently forecast to be more normal, consisting of 14 named storms, including three major hurricanes and four other hurricanes.

Hurricane Katrina was much more about human folly in living in harm's way and below sea level without adequate protection and safety measures than it was about global warming or extreme weather events.

It was extremely effective, however, in generating urban legends.

Kit Webster