09 July 2005

It's not Dennis' Fault, He's a Victim of Global Warming

It happened again. Tonight at about 6:38 p.m. (pdt), ABC News was reporting on all things Dennis. The telecast was going smoothly, for me, until the host took the turn many of us had been dreading since Ivan slammed the panhandle of Florida ten months ago. Global warming. Once again, the MSM pulled the global warming theory into what is already a tragic event (the ABC host also used the word diabolical...but that is a different topic for a different time).
In Florida, they know just how powerful hurricanes can be: Over the last year, they have been reminded more than they care to count.

But it could get even worse.

Could get worse? What's next...reduced air pollution leads to global warming, as well?

According to a recent study, hurricanes will become even more intense because of global warming — the idea that greenhouse gases are heating the earth's atmosphere and oceans.

"Those storms that do occur are going to have the potential to be significantly stronger in a warmer climate," said Tom Knutson, a climate modeler for the Geophysical Fluid Dynamics Lab, and the lead author of the study that used one the world's most powerful computers to simulate 1,300 virtual storms.

Hurricanes get their strength from warm ocean water, so higher water temperatures mean more energy for the storms.

As I recall from Oceanography class, the main energy force that drives hurricanes is, in fact, heat. But heat from a source other than the tailpipe of my truck. The heat that drives hurricanes is caused by warm air rising and condensing to form vapor or clouds -- the folks in the lab call this the latent heat of condensation. Since we all know that Mother Nature abhors a vacuum, more air will be pulled into the system, it will rise, condense and release latent heat of condensation and the cycle continues. This cycle causes a pattern of wind that circulates around a center. In short, an eye is born.

"As a storm is moving across the ocean, it's evaporating water from the ocean's surface, and that's supplying fuel for the storm," Knutson said.

That's right, but what does that have to do with the fact that a physical and chemical process is driving the storm. If ambient air and water temperatures were the sole forces in determining the energy or destructive power of a storm, wouldn't all hurricanes be Cat 5, or Cat 2 for that matter? What is a fact is that we have Cat 5 and Cat 2 storms, yet the air and water temps remain fairly constant within any period of observation during the season. For example, Dennis is turning out to be a very destructive storm, while Cindy never made it to the evening news.

Knutson's study found that within 80 years, the average hurricane strength will increase by half a category in the five-step scale of destructive power.
Funny that. According to The Deadliest, Costliest and Most Intense United States Hurricanes from 1990 through 2000 (and other frequently requested hurricane facts), which was prepared by Mr. Knutson's employer NOAA, hurricanes tend to follow a cyclical pattern. Some decades were lions and others were lambs, as listed below.

Table 5 which lists hurricanes by decades since 1900, shows that during the twenty year period 1960-1979 both the number and intensity of landfalling U.S. hurricanes decreased sharply! Based on 1900-1959 statistics, the expected number of hurricanes and major hurricanes during the period 1960-1979 was 36 and 15, respectively. But, in fact, only 27 (or 75%) of the expected number of hurricanes struck the U.S. with only 10 major hurricanes or 67% of that expected number. The decade of the eighties showed little change to this trend. Even the decade of the nineties, showed below average landfall frequencies. It could be noted that of the most recent four decades, only the 70's and 90's were significantly below normal.











Despite what NOAA reported in the study above, the ABC report goes on to state...
"It could be the difference between, say, a roof staying on a house and the roof being ripped off," said Robert Tuleya of the Center for Oceanography at Old Dominion University.
Or, it could be the differencee between a study that is based in fact and one that uses words such as "potential," "may" and "could."
Average wind speed could jump 15 miles an hour, rainfall two inches and storm surges several feet.
What if it was an abnormally cold, dry day with really low tides?
"In our simulations, you end up with some of these really monster storms," Knutson said.

The study says nothing about how global warming might affect the frequency of hurricanes. The researchers say that is next on their agenda.
I do believe the key word in the last sentence is "agenda."

Open Post Thanks to The Mudville Gazette.
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