As the world watched New Orleans’ devastating descent into squalor last week, questions about connections between global warming and hurricanes reemerged. A few politicians and activists leapt to offer their views, most of which were unmeritorious. So what does the science say?
Investigations of the climatology of tropical cyclones (the generic name for the storms we call tropical storms or hurricanes in the Western Hemisphere) must be broken into at least two separate categories. The first involves storm formation: Is the number of storms changing with time? On a related note, do the regions of tropical cyclone genesis change with climate? The second involves intensity: Is the average or peak wind speed affected? What about a storm’s lifetime (the time from inception to decay or landfall)?
The first of these questions is easiest to answer. The number of storms is not increasing, and there is no theoretical basis to believe that it will. Globally, roughly 90 tropical cyclones form each year. This number has been remarkably stable for as long as a global record has existed — typically var... Read more