 |
 |
 |
 |
 |
|||
September 07, 2005
Correction of Misquote in AP Story
Posted to Author: Pielke Jr., R. | Climate Change
It has been called to my attention that a widely-circulated AP story article from September 1, 2005 by Joe Verrengia has this statement:
"Roger Pielke Jr., who studies the social impacts of natural disasters and climate change at the University of Colorado, said any link between the intensity of Katrina and other recent hurricanes and global warming is "premature.""
This not quite accurate - the difference here is between "hurricanes" and "hurricane impacts". Here is what we say in our BAMS paper (PDF) on this, and presumably where the reference to "premature" comes from:
"To summarize, claims of linkages between global warming and hurricane impacts are premature for three reasons. First, no connection has been established between greenhouse gas emissions and the observed behavior of hurricanes (IPCC 2001; Walsh 2004). Emanuel (2005) is suggestive of such a connection, but is by no means definitive. In the future, such a connection may be established (e.g., in the case of the observations of Emanuel 2005 or the projections of Knutson and Tuleya 2004) or made in the context of other metrics of tropical cyclone intensity and duration that remain to be closely examined. Second, the peer-reviewed literature reflects a scientific consensus exists that any future changes in hurricane intensities will likely be small in the context of observed variability (Knutson and Tuleya 2004, Henderson-Sellers et al 1998), while the scientific problem of tropical cyclogenesis is so far from being solved that little can be said about possible changes in frequency. And third, under the assumptions of the IPCC, expected future damages to society of its projected changes in the behavior of hurricanes are dwarfed by the influence of its own projections of growing wealth and population (Pielke at al. 2000). While future research or experience may yet overturn these conclusions, the state of knowledge today is such that while there are good reasons to expect that any conclusive connection between global warming and hurricanes or their impacts will not be made in the near term."
And Kerry Emanuel says something quite similar on this subject:
"There is a huge upward trend in hurricane damage in the U.S., but all or almost all of this is due to increasing coastal population and building in hurricane-prone areas. When this increase in population and wealth is accounted for, there is no discernible trend left in the hurricane damage data. Nor would we expect to see any, in spite of the increase in global hurricane power. The reason is a simple matter of statistics: There are far too few hurricane landfalls to be able to discern any trend. Consider that, up until Katrina, Hurricane Andrew was the costliest hurricane in U.S. history. But it occurred in an inactive year; there were only 7 hurricanes and tropical storms. Data on U.S. landfalling storms is only about 2 tenths of one percent of data we have on global hurricanes over their whole lifetimes. Thus while we can already detect trends in data for global hurricane activity considering the whole life of each storm, we estimate that it would take at least another 50 years to detect any long-term trend in U.S. landfalling hurricane statistics, so powerful is the role of chance in these numbers."
Posted on September 7, 2005 11:02 AM
Comments
I guess the "premature" doesn't exactly reference intensity, but from this sentence: "First, no connection has been established between greenhouse gas emissions and the observed behavior of hurricanes", it seems like it is still an accurate reflection of your position, is it not?
Posted by: Dylan Otto Krider at September 7, 2005 11:26 AM
Dylan-
Thanks much for these comments. The statement that you reference is a characterization not of a "position" but our assessment of what you will find in the peer-reviewed literature. I am aware of no studies that focus on attributing changes in hurricane behavior to greenhouse gases. Emanuel's paper is suggestive of such a link, but it is not an attribution study.
Here is what Emanuel himself says on this point:
"How can you assert that the upswing in the last 50 years is a consequence of global warming?
A: We cannot say for sure. What we can say is that everywhere we have looked, the change in hurricane energy consumption follows very closely the change in tropical sea surface temperature. When the sea surface temperature falls, the energy consumption falls, and conversely, when it rises, so too does the energy consumption. Both theory and models of hurricane intensity predict that this should be so as well. In contrast to the hurricane record, the record of tropical ocean temperature is less prone to error and goes back 150 years or so. Moreover, geochemical methods have been developed to infer sea surface temperature from corals and from the shells left behind by micro-organisms that live near the surface; these can be used to estimate sea surface temperature for the past several thousand years. These records strongly suggest that the 0.5 degree centigrade (1 degree Fahrenheit) warming of the tropical oceans we have seen in the past 50 years is unprecedented for perhaps as long as a few thousand years. Scientists who work on these records therefore believe that the recent increase is anthropogenic."
It is critical to distinguish what scientists say in the media versus what you will find in the peer reviewed literature. There will no doubt be attribution studies published in the future, and clearly, folks like Trenberth and Gray have different expectations about what those studies will show. Time will tell, and we acknowledge this in our paper. For my part however, I think that the statement that you quote in our paper is a fair and accurate assessment of the current knowledge reflected in the peer-reviewed literature.
Posted by: Roger Pielke Jr. at September 7, 2005 12:31 PM
Link to Kerry Emanuel's statement:
http://wind.mit.edu/~emanuel/anthro2.htm
Posted by: Roger Pielke Jr. at September 7, 2005 12:40 PM
I was just trying to get at clearer idea of where you thought you were misrepresented. Having quoted scientists before, I'm interested in figuring out how we laymen get led astray. It seemed like the "premature" was not referring to intensity but impacts - I get that. But it also seemed like the characterization of your assessment of the peer reviewed literature was correct. I'm clearer now. Thanks.
Posted by: Dylan Otto Krider at September 7, 2005 12:56 PM
Dylan-
I see. The "premature" was OK. It was the reference to "global warming and hurricanes" that was incorrect. Our paper acknowledges the possibility for an effect of global warming on hurricanes. It is premature however to assert a linkage between "global warming and hurricane impacts."
Posted by: Roger Pielke Jr. at September 7, 2005 01:00 PM
Stefan Ramsdorf has kindly pointed out to me that a recent article in Der Speigel that quotes me includes the same confusion between "global warming and hurricanes" and "global warming and hurricane impacts." This is a subtle point, perhaps, and I am going to make sure I emphasize it with reporters in the future, thought most, by far, accurately have reported my views.
Posted by: Roger Pielke, Jr. at September 8, 2005 10:26 AM
Similarly, Katy Human makes the exact same mistake confusing "global warming and hurricanes" with "global warming and hurricane imapcts" in a Denver Post article today:
http://www.denverpost.com/search/ci_3033681
Posted by: Roger Pielke, Jr. at September 16, 2005 11:30 AM