New study predicts fewer but more intense hurricanes as a result of global warming

By Michael J.W. Stickings

In the wake of Hurricanes Katrina and Rita a couple of years ago, there was a good deal of discussion about the relationship between global warming and hurricanes (and other such major natural phenomena). As I put it in a link-filled post at the time: Were these larger, more powerful hurricanes related to climate change, or not? Put another way, has global warming directly caused these larger, more powerful hurricanes?

While there is general consensus among scientists on the reality and causes of global warming, there has been disagreement over particulars, including the hurricane issue: How will global warming affect the frequency and intensity of hurricanes? The research I've come across -- and, admittedly, I'm hardly an expert on the matter -- suggests that hurricanes will be more intense overall but that they would not be more frequent. (For more on this, click on the link in the first paragraph, above.)

A new study backs this up:

Hurricanes and tropical storms will become less frequent by the end of the century as a result of climate change, US researchers have suggested.

But the scientists added their data also showed that there would be a "modest increase" in the intensity of these extreme weather events.

The findings are at odds with some other studies, which forecast a greater number of hurricanes in a warmer world.

The study was conducted by researchers at the National Oceanic and Atmospheric Administration's Geophysical Fluid Dynamics Laboratory (GFDL). "The model is simulating increased intensity of the hurricanes that do occur, and also increased rainfall rates," said Dr. Tom Knutson, the study's lead author. However, "[w]e do not regard this study as the last word on this topic."

It would seem to make sense, given rising sea-surface temperatures, that hurricanes would get more intense overall as a result of global warming, but the "reduction in hurricane frequency in the Atlantic" predicted by the GFDL (using a new model that "simulate[s] the fundamental fluid dynamics and thermodynamics that control hurricane genesis in the Atlantic in a numerical model to a very high resolution") seems to be a curious finding.

Regardless, whatever the frequency of hurricanes going forward, what seems to be more clear now is that they will be getting more intense. In other words, there will be more Katrinas and Ritas as global temperatures rise.

All the more reason -- not that there is not already reason enough -- to confront in a meaningful and sustainable way the most pressing crisis of our time, one that threatens everyone everywhere, not just the inhabitants of New Orleans.