By Bill Kovarik
The probability of a storm like Hurricane Katrina hitting the New Orleans area was high, according to historical and paleohistorical records studied by paleotempestologist Kam-biu Liu, a professor in Louisiana State University's Department of Geography and Anthropology. Dr. Liu's discipline involves the use of fossils to study hurricane activity on a millennial scale. A variety of other experts on various hurricane subjects can be found at the LSU Hurricane Center.
The Environment Writer newsletter says Professor William Gray at Colorado State University is the "unofficial guru of Atlantic seasonal hurricane prediction." Dr. Gray has posted forecasts on the Colorado State Web site. "Our seasonal analogs continue to point toward a very active season," Gray said in early August 2005. The National Weather Service's Climate Prediction Center also issued a hurricane forecast, which said 2005 was shaping up to be "hyperactive."
One obvious question is whether Katrina was fierce because of global warming or because other factors dominated. "The evidence strongly suggests more intense storms and risk of greater flooding events," said Kevin Trenberth of the National Center for Atmospheric Research. But global warming is only one of many factors.
The effects of global warming on hurricanes are minor at most, say Chris Landsea, new director of science for the National Hurricane Center, and Roger Pielke, atmospheric science professor at Colorado State.
The Pew Center on Global Climate Change notes that scientists have found a multi-decade cycle of storm activity that is not directly related to global warming. "We see periods of high hurricane activity that last for several decades followed by periods of low hurricane activity," the Pew report said. "Unfortunately, during the mid-1990s, it looks like we reentered an active phase that will persist for some time." Also see the American Geological Institute's Web site for more information.
These studies tended to focus on numbers of hurricanes. A scientist who looked at the intensity of hurricanes found they have grown significantly more powerful and destructive over the last three decades due in part to global warming.
"Future warming may lead to an upward trend in [hurricanes'] destructive potential, and -- taking into account an increasing coastal population -- a substantial increase in hurricane-related losses in the 21st century," said Kerry Emanuel in a paper appearing in the July 31 online edition of the journal Nature.
An important blog that lets scientists debate detailed facts and helps inform journalists is RealClimate.org. The blog was originally put together by Gavin Schmidt and Michael Mann. One section of RealClimate.org has a detailed debate on the connections between global warming and hurricanes.
Most regions have universities with scientists who are part of the international climate science community. Finding them and interviewing them means taking time to get briefed first, but the experience is not as exotic or as difficult as many reporters believe. One good resource for local scientific experts with real research credentials is the Science Citation Index, a research tool available in most university libraries. The index can help you find out who is publishing research at your local universities.
