A hundred Katrinas: Climate change and the threat to the U.S. coast

Mother Jones: As the atmosphere heats up and polar ice caps melt, sea levels are projected to rise significantly, sending water lapping against coastal flood defenses around the world. And if that added heat fuels bigger hurricanes, as many scientists now believe, Katrina-like storms won't strike once a century, but possibly once a generation. And if that still seems infrequent enough, consider this: For every catastrophic storm, we experience dozens of minor disasters, and many of those will strike harder, or in unexpected places. If so far you've been among the majority of Americans who haven't had to worry about floods or hurricanes, that may soon change.

…It's relatively easy to prepare for a high tide. The far less predictable threat from rising seas will be storms. Not every hurricane is a Katrina, but rising sea levels increase the likelihood and the intensity of flooding even from smaller tropical storms and nor'easters….

New Orleans is the American city most vulnerable to this threat, but it's far from the only one. Galveston, Houston, Tampa, Charleston, and even New York are also exposed, and residents all along the Atlantic and Gulf coasts, from Maine to Texas, will face increasing risks...

In some sense, we had it coming. Ever-expanding shoreline development has steadily increased the size and costs of disasters—there is simply more stuff to be destroyed along the coast than there used to be…

What's the best approach to this problem? A 2005 report by the Association of British Insurers suggested that reducing carbon emissions could reduce insured losses from extreme weather events by 80 percent, or $35 to $50 billion per year, the equivalent of two Hurricane Andrews. But Roger Pielke Jr., a professor of environmental studies at the University of Colorado, says that even if the world enacts the principal fix for global climate change—reducing carbon dioxide emissions—it will probably be too slow and indirect to have much effect on disasters. Instead, he suggests nations do it the old-fashioned way—either protect people or move them out of harm's way.