Tuesday, 15 January 2002: 3:00 PM
The recent increase in Atlantic hurricane activity: Causes and implications
The years 1995 to 2000 experienced the highest level of North Atlantic hurricane activity in the reliable record. Compared with the generally low activity of the previous 24 years (1971 to 1994), the last six years have seen a doubling of overall activity for the whole basin, a 2.5-fold increase in major hurricanes (>=50 m/s), and a fivefold increase in hurricanes affecting the Caribbean. The greater activity is caused by simultaneous increases in North Atlantic sea surface temperatures and decreases in vertical wind shear, both of which are known to favor hurricane formation. Because these changes exhibit a multidecadal time scale, the present high level of hurricane activity is likely to persist for an additional ~10 to 40 years. The shift in climate calls for a reevaluation of preparedness and mitigation strategies.