London, May 19 : A new study has suggested that hurricanes might become rarer in the Atlantic throughout the 21st century if the world continues to warm.
According to a report in Nature News, Thomas Knutson of the US National Oceanic and Atmospheric Administration (NOAA) and colleagues carried out the study.
They used a regional climate model of the Atlantic basin to simulate the observed increase in hurricane activity between 1980 and 2006, on the basis of observed sea-surface temperatures and atmospheric conditions.
They then used two versions of the model, one assuming climate warming of 2.8ºC by 2100, and one without warming, to estimate whether hurricane activity will continue to increase in the region as a result of human-induced climate change.
"The study does not support the notion that rising greenhouse gases are causing an increase in tropical storm frequency," said Knutson.
Knutson and his team have estimated that overall, the number of hurricanes will decrease, with weaker storms feeling the greatest impacts. They predict a 27% drop in tropical storms, 18% fewer hurricanes and 8% fewer 'major hurricanes'.
So, despite the fact that hurricane activity has increased dramatically in the Atlantic over the past 25 years, this trend will not continue until the end of the century under warmer conditions.
"We can't simply extrapolate the trend from the past 25 years into the future," says co-author Issac Held, from NOAA.
The study focused primarily on changes in the number of hurricanes, but also projected a shift towards more intense storms and heavier rainfall events.
This largely concurs with recent work by Kerry Emanuel, a hurricane expert at the Massachusetts Institute of Technology in Cambridge.
Using a different type of model, Emanuel projected that global warming will result in fewer hurricanes globally, but that they will become more intense in some locations.
According to Kevin Trenberth, a climatologist at the National Center for Atmospheric Research in Boulder, Colorado, "The results suggest fewer tropical storms in the Atlantic, and this seems reasonable given everything else we know."