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August 31, 2005

Connecting the Dots -- Hurricane Katrina and Global Warming

Science published a new study suggesting that numbers and intensity of hurricanes are growing in the North Atlantic, but not in other oceans that are experiencing temperature increases.      At the beginning of August, we knew that there would be more tropical storms/hurricanes.  See post of 8/2/05.  Hurricane frequency/dead zone post.  That post reported NOAAs August hurricane outlook. ( Expert Assessments: Atlantic Hurricane Outlook Update).  We also knew that the increasing intensity of tropical storms/hurricanes has been tied to climate change.  See post of 8/1/05. Hurricane intensity post , Trenbarth Summary, discussion on the climate science scientists' blog: Real Climate Storms and Global Warming , NOAA site       , Knutson and Tuleya.   As hurricanes hit land, they increasingly encounter densely developed areas -- due to population growth and government policies that encourage development in vulnerable areas [I'm willing to go out on a limb here] -- that have lost their natural ability to absorb floods because of the destruction of wetlands [which is one of the principal reasons we protect wetlands].

    Population growth, development in vulnerable areas, wetlands destruction, poor engineering, failure to fund known and feasible preventative measures and inadequate response planning are all culprits.


    The way I connect the dots of climate change is that the climate change we are inducing is taking and will increasingly take a huge toll in human life -- including human lives destroyed in hurricanes like KatrinaHurricane Katrina impacts    The climate change approach that has been pursued by the United States, which fails to aggressively address climate change and prevent such tragedies (and the enormous array of other adverse impacts), is morally bankrupt.


    The number and intensity of hurricanes during a particular hurricane season vary widely.  However, intensification of even a naturally increasing or varying number of hurricanes means more destruction.  An individual hurricane like Katrina is not "caused" by global warming.   Several of my colleagues have pointed out that one should be careful about  linking hurricanes to climate change.    Because of the large natural variation in number and intensity of hurricanes during a given year and the natural cyclical nature of the variation, it is hard for scientists to prove (or disprove) a trend -- and it is, of course, impossible to say a particular hurricane was "caused" by global warming.   Another colleague has underscored this point by pointing to a paper released by Pielke Jr. as Katrina approached the Gulf Coast.  Hurricanes and Global Warming.  See also Pielke Jr. blog  Prometheus  [FYI: Pielke Jr is a political science/science policy person and Pielke Sr. is the meteorologist.  Both have been key players in questioning the accuracy of climate change modeling and stressing that the climate changes induced by humans are not limited to greenhouse gas emissions, but include landscape changes and aerosol emissions -- fair enough, but beside the point for purposes of this discussion]. 

    Another colleague points out that natural cycles and global warming are not mutually exclusive explanations of an increase in number or intensity of hurricanes.   

    Even if climate change is a small factor in increasing numbers of intense tropical storms and even if hurricanes are a "minor" part of the adverse impacts from climate change -- that does not make any intensification  of the increasing number of hurricanes unimportant.  The impacts we have witnessed from an "indirect hit" on New Orleans from a major hurricane hopefully put human faces on the word "intensification."





August 31, 2005 in Climate Change | Permalink


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» Katrina, hurricanes and global warming from Quicksilver כספית
I caution against blaming Katrina on global warming, as does Ross Gelbspan (generally a good environmental journalist). Granted, oil and energy policies should change, but Arthur Waskow overplays the Katrina card. See the analysis, links and debate at ... [Read More]

Tracked on Aug 31, 2005 4:34:00 PM


What do you think about the idea that the private sector (e.g., insurance companies) will push harder for greenhouse gas control, given these potential effects? It always seems that env. law changes are more likely, or perhaps work better, when economic interests are consistent with the change.

Posted by: Jerry Anderson | Aug 31, 2005 1:33:59 PM

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