Global Warming and Hurricanes

by Don Boudreaux on August 21, 2006

in Environment, Risk and Safety

With the one-year anniversary of hurricane Katrina fast
approaching, I want to share some findings reported by Bjorn Lomborg in his
2001 book The Skeptical Environmentalist (pages 294-295).

The observed evidence counts against the idea of increased
frequency of tropical cyclones.  Generally,
it has been impossible to establish a reliable global record of variability of
tropical cyclones through the twentieth century because of changing observing
systems and population changes in tropical areas.  Based on relatively short time series, the
Northwest Pacific basin has shown an increase in tropical cyclones since 1980,
preceded by an almost identical decrease in frequency from about 1960 to 1980.  Since the 1960s, the Northeast Pacific has
experienced a significant upward trend in tropical cyclone frequency, the North
Indian Ocean a significant downward trend, and not appreciable long-term
variation was observed in the Southwest Indian Ocean and Southwest Pacific.  Finally, the
numbers of tropical cyclones occurring in the Australian region have decreased
since the mid-1980s.

However, the North Atlantic has good cyclone data because weather aircraft have reconnoitered there since
the 1940s. Here, it turns out that
although there are great decadal variations, the trends are generally
declining, with a noticeable quiet period in the 1970s and 1980s.  Particularly, it turns out that the number of
intense cyclones (those that cause the greatest damage) has been declining, as
has the number of cyclone days.  Equally,
and as shown in Figure 152 [unavailable on line], the average [maximum sustained] wind [speed] of an
Atlantic cyclone has been decreasing over the past half-century.

These data, of course, are pre-Katrina (which was a category
three storm when it made landfall on August 29, 2005, just east of New Orleans – and which, despite being a major
tragedy, doesn’t come close to being a killer of the magnitude of the hurricane that hit Galveston, Texas, in 1900).

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{ 8 comments }

Mcwop August 21, 2006 at 2:55 pm

People may want to check this out:

"Mixing Politics and Science in Testing the Hypothesis That Greenhouse Warming Is Causing a Global Increase in Hurricane Intensity"

http://ams.allenpress.com/pdfserv/10.1175%2FBAMS-87-8-1025

kebko August 21, 2006 at 4:33 pm

In my paper today (sorry, no link) was, I think, an AP story about a group of economists (from Britain I think?) who had published "research" about the effects of global warming on levels of tourism in different parts of the world a CENTURY from now. Using a very complicated computer model they had developed, they concluded things such as, the U.S. will experience an 18% increase in tourism by the year 2100 due to the effects of climate change. This is off the top of my head, but the numbers were in the ballpark of this. Insanity.

I also noticed a report on NPR recently on wetlands in China:
http://www.npr.org/templates/story/story.php?storyId=5516296

Where environmental issues were partly blamed on global warming. It seems to me that the issues at hand were entirely local, tying it to "global warming" would require an unimaginably large amount of further research into the connection between the local climate, the world climate system, and the changes that even climatologists are still trying to understand. This was certainly just a tacked on interpretive comment on what was probably good local research. The constant use by scientists of the idea of "global warming" as a knee-jerk explanation for everything, in a most un-scientific way, seems to me to feed a hype machine, which, if anything, hinders our ability to actually understand what exactly is going on.

spencer August 21, 2006 at 5:10 pm

"the North Atlantic has good cyclone data because weather aircraft have reconnoitered there since the 1940s"

Yes, but a year ago you argued with me that this government activity that gave warnings
of impending storms in time for people to take defensive measures was not the major reasons deaths from huricanes have been much lower since WW II.

Are your anti-government feeling being tempered with age?

Randy August 21, 2006 at 5:11 pm

I remember from one of my CIS classes a discussion about the use of computers to predict the weather. Bottom line was that predicting the weather accurately for more than a few days in advance was impossible for even the most powerful super computers due to the enormous number of variables involved. And yet somehow these folks claim to have an algorithm to accurately predict the climate of the entire earth several years in advance. Let's just say I'm skeptical.

James Pyrich August 21, 2006 at 9:13 pm

Predicting which direction the climate will go and what its effects on local weather systems will be is sort of like predicting which direction the economy will go and what its effects on coffeehouses will be.

It's not so much that you can't do it, but likely as not, your prediction will fail in the general sense, and it is doomed in the specific sense.

That is to say, you may be able to indicate general trends, but that's just about it. And I don't think it's a matter of not having enough variables. Accurately modeling an individual human being's behavior from moment to moment is nigh impossible due to the vast complexity of what makes up a person. Even if an individual was modeled perfectly in an instant, once a human being acts, or refrains from acting, that person is physically changed–a synapse in the brain is strengthened or weakened, thus subtly throwing off what might have been a perfect model.

That being said, when we know others well, we get a pretty good sense of what will happen next given a set of circumstances.

All of what I have said merely serves the purpose of illustrating that reality is not purely deterministic. There are trends and laws which we are bound by, but they are by no means predictive in anything but the most general sense.

True_Liberal August 21, 2006 at 11:02 pm

Donald, I am surprised and disappointed that you have been suckered into the journo-speak "one-year anniversary" – an illiterate redundancy IMHO. How can an anniversary have an connotation other than ANNUAL? Why not "first anniversary"?

On the other hand – I should be glad you haven't fallen for "six-week anniversary"!

shane August 22, 2006 at 6:54 am

Global warming-an alarm,which is rising temprature of head's sweat and worries.Considerations are precurably neccesity.

Noah Yetter August 22, 2006 at 11:24 am

spencer,
You do realize you're quoting Lomborg not Boudreaux, right?

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