Atlantic Multidecadal Oscillation is a widely held belief that decades-long cycles are responsible for storms. An active period ended in 1900, followed by relative calm until 1930, high activity until about 1970, and calm again until the recent period of higher-than-normal storm activity began in 1995, scientists say.
Emanuel, a respected hurricane researcher at Massachusetts Institute of Technology, disagrees. The recent upswing in storms is largely due to human-induced climate change, he contends.
His calculations show a rise in activity to about 1950, followed by a decline to about 1980, then a rapid increase, the Houston Chronicle reported. This does not conform to temperature cycles, Emanuel says.
Arriving at solid answers is difficult because historical records are not as reliable as current measurements gathered from satellites, airplanes and sophisticated sea equipment.
One problem with the accepted theory is that -- despite the apparent relationship between oscillating sea temperatures, atmospheric changes and hurricane activity -- scientists have yet to find an explanation in nature for why such a cycle would exist, the newspaper said.
Copyright 2006 by United Press International
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