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“HURRICANS AND GLOBAL WARMING”

By R A Pielke Jr, C Landsea, M Mayfield, J Laver, and R Pasch

Bulletin of the American Meteorological Society

November 2005






Ted Gerhard 6/9/2006

INTRODUCTION

This article called “Hurricanes and global warming” is about the potential for global warming to cause increased hurricane intensity and frequency. The idea is that increased carbon dioxide in the atmosphere caused by pollution will trap more heat from the sun on earth. This increased heat in the air would heat up the waters of the world, and of particular concern to America, the waters in the central Atlantic Ocean. One of the ingredients in hurricanes is water temperature, so some worry that a product of our pollution may be more hurricanes.
However, contradictory to people’s fears, the findings in this article suggest that global warming will have an exceedingly small effect on hurricanes. Compared to the damage that hurricanes will cause due to population growth and wealth increases in areas effected by hurricanes, the extra cost in hurricane damages caused by global warming will be negligible. Although there is always uncertainty in predicting the weather, this article says that we do not need to worry about bigger and larger hurricanes due to global warming.

SUMMATION
"There's a push on climatologists to say something about extremes, because they are so important. But that can be very dangerous if we really don't know the answer" (p.1) Because of the politics of climate change, there is pressure on climatologists to provide answers, which is hard when the subject is so full of uncertainty, the article stated.
This article talks about “event risk” and “out come risk.” Event risk is hurricane force projections. Out come risk takes into account vulnerability plus event risk projections to project overall loss. This article weighs global warming in the context of event risk and vulnerability.
The Authors first explore event risk of hurricanes from global warming. Lately there seems to be a hurricane season. Due to the recent spike in hurricane occurrence, some have speculated that global warming might be causing it. Nevertheless, according to the authors “The current state of climate science does not support so close a linkage” (p.2).
The writers concede that heat acts like fuel for hurricanes and that from that perspective it is logical to think that global warming will make a difference in the event risk of hurricanes. However, all models and understanding of hurricanes suggest that it would take much more heat than global warming will deliver to make a big change. The authors bring up a study in 2004 that extrapolated that by 2080 hurricane speeds would increase in average intensity by 5%, but a study in 2005 found that the increased intensity would be more like half of that. Theoretical work as early as 1987 suggests that it would require a 2 degree Celsius increase to cause a 10% increase in storm intensity, and global warming is not expected to get past one degree Celsius.
The authors also mention that although the number of hurricanes has been increasing rapidly since the early 90’s, that is just a part of a cycle. There were a lot of hurricanes from the 1940’s to the 1960’s, but few hurricanes from the 1970’s to the early 1990’s. This new surge in hurricanes appears to be from this cycle rather than global warming.
As for the vulnerability and out come risk, the authors say hurricane destruction will increase dramatically in the future, but it will not be from increased hurricane intensity. As more wealth accumulates in Florida and more people move there, the hurricane seasons will cause more destruction. The Article read “By 2050, for every additional dollar in damage that the IPCC expects to result from the effects of global warming on tropical cyclones, we should expect between $22 and $60 of increase in damage due to population growth and wealth.”(p.5)
The Article concluded that linking increasing green house gases to increased hurricanes is premature because no connection has been established. Furthermore, peer reviewed works demonstrate a scientific consensus that the effects of global warming will be small. Finally, much more devastation is going to be caused because of growth in the future than global warming in terms of hurricanes.

ANALYSIS
The first time through the article was difficult to make sense of, especially the first few pages. However, upon carefully reexamining the text, the article became clear. I noticed no spelling or punctuation errors, and the authors seem to have a great grasp of the English language. Overall, the article is very well written, but one can not skim over it very well. One must take it sentence for sentence to make good sense of it, particularly in the beginning.
The authors seemed excellently objective, as one would expect of authors from a scientific publication. Although critical of the effects global warming on hurricanes, they did not seem to be “Exxon mobile scientists” because they backed up all of their claims effectively. The authors of this piece did not stray form the subject at hand, and seemed to discuss all relative matters thoroughly.
It is hard for me to disagree with them because I do not know a lot on the subject, and the authors covered their bases well. Good science is very hard to argue with unless some new data comes along that challenge the preexisting notions. The authors said that if the growth in population and wealth in Florida stays at about 5% annually, than every 15 years the amount of damage caused by hurricanes there will double. Looking to the future, I would guess that this wouldn’t happen because eventually people will stop moving to Florida if the hurricanes there cost them so much. However, last time I checked, a lot of people keep moving to Florida.
I do have one question to ask the climatologists, what about the effects of the jet streams slowing down on hurricanes? As global warming melts the ice caps, that introduces fresh water into the North Atlantic Ocean. This decreases the amount of salt per volume of water in the North Atlantic. Because of the different heating characteristics of salt water and fresh water, this will slow down the ocean conveyers that circulate the ocean’s water.
Normally hot water from around the equator circulates to the north, and according to commonly accepted models, brings Europe about 40% of its heat. Likewise, cold waters from the north have a big effect on cooling the Atlantic in the vicinity of the equator. If the jet stream began to slow down, then there would be significantly hotter waters around the equator. Of course the hot water would promote hurricanes, but I would like to know what the effects of the ocean currents slowing down would be on hurricanes.