The calm before the storm 18 August 06

It’s been ominously quiet so far in the tropical Atlantic. Not a single hurricane, and we’re already half-way through the season. Clearly it’s going to be a very different kettle of fish from last year’s sequence of disasters, despite the continuing presence of warmer-than-average waters in the region. It’s a different story too in the Pacific, which has seen a very active typhoon season, with the worst storm for 50 years causing serious problems in coastal China.

High Tide readers may remember one of my interviewees, James Elsner of Florida State University, who I interviewed in Tallahassee as a tropical storm poured down outside. Elsner has just published a paper in GRL which supports the contention that global warming is making hurricanes more intense, and that this trend will continue into the future.

“The large increases in powerful hurricanes over the past several decades, together with the results presented here, certainly suggest cause for concern,” says Elsner. “These results have serious implications for life and property throughout the Caribbean, Mexico, and portions of the United States.”

He continues: “I infer that future hurricane hazard mitigation efforts should reflect that hurricane damage will continue to increase, in part, due to greenhouse warming. This research is important to the field of hurricane science by moving the debate away from trend analyses of hurricane counts and toward a physical mechanism that can account for the various observations.”

This is all of much more than academic interest to anyone living in the Gulf Coast area of the United States – any repeat of the Katrina disaster could again displace millions and leave hundreds of thousands more homeless. Indeed, Lester Brown of the Earth Policy Institue refers to the quarter of a million people still displaced from New Orleans and surrounding areas by Katrina as the world’s first large-scale movement of climate refugees. He points out that New Orleans still has only half its pre-hurricane population.

Brown concludes: “More destructive storms are an early manifestation of global warming. The longer term risk is that rising temperatures will melt glaciers and polar ice caps, raising sea level and displacing coastal residents worldwide. The flow of climate refugees to date numbers in the thousands, but if we do not quickly reduce CO2 emissions, it could one day number in the millions.”

On a much smaller scale, some of the first indigenous people to be displaced by global warming could be the Torres Strait islanders off the north coast of Australia. Storm surges are battering down sea walls and flooding homes on an increasingly severe basis – leading many to consider evacuating the islands for good. Watch more on an excellent multimedia slideshow by CSIRO’s Donna Green.