article by Mr. Spiegler was published in the South Florida Sun-Sentinel
Opinion Editorial section on Monday, December 24, 2007.
Global Warming and
I read with interest the
article by Ken Kaye on two scientist's challenge of other scientist’s
linking warmer oceans to more intense hurricanes (Sun-Sentinel page
1, December 13, 2007).
The consensus belief, as
reported by the media and the article is that “global warming eventually
will spawn super-strong storms – the warmer the oceans the more powerful the
hurricanes.” Also stated in the article is that “a large segment of the
scientific community say a growing number of studies hold that global
warming is steadily increasing the intensity, duration, and number of
tropical systems”. Those beliefs imply that global warming is THE major
factor for hurricane intensity and for more, longer lasting, storms. To
characterize it that way, is at best, overly simplistic. In fact, it is
There are many complex
and interrelated factors that determine the intensity of tropical cyclones
(“hurricanes” in the Atlantic Basin – “typhoons” in the tropical north
Pacific). The recent season had 15 named storms – an above average season.
NOAA predicted an above average season, based in part on above average sea
temperatures in the tropical waters. It was an above average season for the
number of storms. Six of the 15 storms became hurricanes. However, 9 of the
15 storms existed as a tropical storm or hurricane for only 2 days and
another lasted 3 days. Clearly, the higher sea surface temperatures did not
play the major role in either the intensity or the duration of the storms
during this season.
I agree with the idea
alluded to by the authors of the study (Vecchi and Soden) that challenged
the concept implying that global warming would be the major factor for more
intense hurricanes. I believe that large-scale hemispheric wind patterns, in
conjunction with atmospheric thermodynamics are the very important factors
for determining the intensity of tropical cyclones.
Hard evidence of that
belief is based, in part, on an average of about 100 tropical disturbances
travelling over warm tropical waters with only about 10%, on average,
developing further into named storms and an average of a little more than 5%
becoming hurricanes. There needs to be both necessary and sufficient
atmospheric and oceanic conditions to generate hurricanes, and in
particular, very strong hurricanes.
One can say, other
things being equal, the temperature of the sea surface IS a major
factor for the intensity of hurricanes. To imply, or make a blanket
statement, that global warming is, by itself, to blame for more, and
stronger, longer duration hurricanes, is incorrect.
David B. Spiegler of DBS Weather Impact
Corporation, Delray Beach, is a Certified Consulting Meteorologist
and a Fellow of the American Meteorological Society. He has studied
hurricanes and has published research in peer-reviewed scientific journals.