NARRAGANSETT – August 5, 2011 – Scientists have been predicting for years that the Northeast would see more frequent and intense hurricanes as temperatures increase due to climate change.

Isaac Ginis, a hurricane expert at the University of Rhode Island, has some good news. It appears, based on new scientific data and improved ways of analyzing existing data, that there isn’t any discernable, significant trend towards more hurricanes. In fact, forecasting models suggest that the number of hurricanes may actually decrease.

Why the change? A major factor is atmospheric stability—the more unstable the atmosphere, the greater the probability that a potential storm will grow from a tropical depression to a hurricane. However, once atmospheric temperature reaches a given level of “hot,” the upper air masses actually become more stable and create conditions that don’t promote the formation of hurricanes. Therefore, we should see fewer Category 1, 2, and 3 hurricanes.

However, there is a down side, and that is confirmation of the prediction for more powerful hurricanes. A hotter atmosphere creates the conditions—lots of hot air, which holds more moisture—that generate hurricanes that are bigger and more powerful. So while we may see fewer hurricanes overall, we may see more Category 4 and 5 hurricanes. And more moist air may increase rainfall rates, too.

Ginis spoke about the recent projections of future hurricane activity at a symposium on the research undertaken as part of the University of Rhode Island Climate Collaborative funded by Rhode Island Sea Grant. The collaborative’s goals are to improve what is known about climate change, particularly in the Northeast, and to share that information to help communities adapt to climate change. For more information, see seagrant.gso.uri.edu/coast/a_hazard_theme.html .