Earth & Sky

Study predicts more intense, but fewer, hurricanes

A new study – based on computer modeling – indicates that, while Atlantic hurricanes can be expected to become more intense as climate warms, there might not be as many of them.

Tom Knutson: We re-ran experiments where we changed the climate to be a much warmer climate such as we would expect by late in this 21st century. And we found that in the warmer climate there were fewer hurricanes simulated than for the present climate.

That’s Tom Knutson, a research meteorologist at NOAA’s Geophysical Fluid Dynamics Laboratory in Princeton, New Jersey.

Tom Knutson: We think the most important result coming out of this study is that it does not support the idea that there’s a large, greenhouse-gas driven increasing trend in Atlantic hurricane or tropical storm frequency.

Knutson’s model showed a 27 percent drop in the tropical storm count and an 18 percent decrease in the number of hurricanes in the warmer climate expected at the end of this century. The same study also showed a link between climate warming and stronger hurricanes.

Tom Knutson: And we also found that the hurricanes that did occur had higher intensities than those in the present climate, by a few percent, and also higher rainfall rates.

Knutson spoke of continued uncertainties.

Tom Knutson: This is not the last word on this topic by any stretch.

To predict the amount of climate change through 2099, Knutson’s team took the average climate change from more than a dozen models. He admitted this is a source of uncertainty in the study.

Tom Knutson: There is quite a bit of spread in the results depending on what global climate model you use. Another limitation of our study, an important limitation, is that our model does not simulate hurricanes as strong as those that occur in nature.

He plans to address these limitations in future studies.

Our thanks to NOAA, the Natioanal Oceanic and Atmospheric Administration.