NOAA: Atlantic hurricanes fewer but stronger

As the aftermath of Myanmar's hurricane continues with the United Nations stuggling to send relief, a new model simulation of Atlantic hurricane activity for the last two decades of this century projects fewer but stronger hurricanes overall, according to the National Oceanic & Atmospheric Administration.
The study shows a "slight increase in intensity for hurricanes that do occur."
Hurricanes are also projected to have more intense rainfall, on average, in the future. The findings are reported in a study by scientists at NOAA's Geophysical Fluid Dynamics Laboratory in Princeton, N.J., published online on May 18 in Nature Geoscience.
In a preliminary study published last October in the Bulletin of the American Meteorological Society, the new model was shown to successfully reproduce Atlantic hurricane counts year-by-year from 1980 to 2006, including the observed increasing trend.
In the new study, the model was used to test the influence of greenhouse gas warming on Atlantic hurricane activity through the end of the 21st century. Simulations reveal higher levels of wind shear and other changes, which act to reduce the overall number of hurricanes in the model.
Tropical Atlantic sea surface temperatures have increased over the past century and several studies have reported strong correlations between increasing tropical Atlantic sea surface temperatures and measures of hurricane activity since at least 1950. Although it is widely accepted in the climate change research community that increases in greenhouse gases have caused most of the global warming of the last half century, the link between increasing greenhouse gases and hurricane activity has been a topic of wide debate and of little consensus.
This new study suggests that in the Atlantic basin, global warming from increasing greenhouse gases will have little impact, or perhaps cause some decrease, in tropical storm and hurricane numbers.
Large-scale environmental changes in circulation, such as wind shear, as well as possibly moisture, are likely the dominant factors producing the reduced storm frequency. These results support recent research showing that the primary driver of the recent increase in Atlantic hurricane numbers was the warming of the tropical Atlantic relative to the other tropical basins.
An increase in hurricane intensities globally is assessed as "likely" in the Intergovernmental Panel on Climate Change Fourth Assessment Report issued in 2007.
Provided by a NOAA press release