Global warming increases intensity of hurricanes and cyclones

The debate so far. Using computer modeling conventional scientific wisdom had it that the .5 degree increase in ocean surface temperatures over the past 50 years was not causing an increase in the intensity and frequency of hurricanes.

I checked this up after Hurricane Katrina, curious to know whether global warming was making weather events more extreme. The conventional wisdom was that this would not really happen until 2050 at the current rate of the ocean's surface temperature increase.

Then I heard that someone decided to compare the results of the computer modeling with real historical weather data, getting results that challenge this conventional wisdom:

The analysis by climatologist Kerry Emanuel of the Massachusetts Institute of Technology shows for the first time that major storms spinning in both the Atlantic and the Pacific since the 1970s have increased in duration and intensity by about 50 percent.

This conclusion is also being backed up by independent new research conclusions:

Global warming could be behind a dramatic rise in the number of ferocious hurricanes and tropical cyclones, new research suggests.

As the oceans have warmed, the incidence of Category 4 and 5 storms like Hurricane Katrina has almost doubled.

"What we found was rather astonishing," said Peter Webster, of the Georgia Institute of Technology in Atlanta, whose team studied the number, duration and intensity of hurricanes worldwide in the past 35 years.

In the 1970s there were, on average, 10 intense storms with winds above 200 kilometres an hour each year. Since 1990 this figure has risen to 18.

Professor Webster said the findings established a link between sea surface temperature, which has risen by about half a degree since 1970, and increasing storm intensity.

Professor Webster also pointed that the link is not simple and that more research was needed. The debate continues.