NOAA ATTRIBUTES RECENT INCREASE IN HURRICANE ACTIVITY
TO NATURALLY OCCURRING MULTI-DECADAL CLIMATE VARIABILITY

Nov. 29, 2005 - The nation is now wrapping up the 11th year of a new era of
heightened Atlantic hurricane activity. This era has been unfolding in the
Atlantic since 1995, and is expected to continue for the next decade or
perhaps longer. NOAA attributes this increased activity to natural occurring
cycles in tropical climate patterns near the equator. These cycles, called
"the tropical multi-decadal signal," typically last several decades (20 to
30 years or even longer). As a result, the North Atlantic experiences
alternating decades long (20 to 30 year periods or even longer) of above
normal or below normal hurricane seasons. NOAA research shows that the
tropical multi-decadal signal is causing the increased Atlantic hurricane
activity since 1995, and is not related to greenhouse warming.

http://www.magazine.noaa.gov/stories/mag184.htm