Nicholas Kristoff writes in The New York Times:
If the White House wants to move the debate about Hurricane Katrina beyond what it calls the "blame game" for bodies decomposing in the streets of New Orleans, then here's a constructive step that President Bush could take to protect people in the future: Tackle global warming.
True, we don't know whether Katrina was linked to global warming. But there are indications that global warming will produce more Category 5 hurricanes. Now that we've all seen what a Katrina can do - and Katrina was only Category 4 when it hit Louisiana - it would be crazy for President Bush to continue to refuse to develop a national policy on greenhouse gases.
"The available scientific evidence indicates that it is likely that global warming will make - and possibly already is making - those hurricanes that form more destructive than they otherwise would have been," declares an analysis by five climate scientists at http://www.realclimate.org
Hurricanes derive their power in part from warm water, and so forecasting models show future hurricanes becoming more severe as sea surface temperatures rise. One summary of 1,200 simulations published in the Journal of Climate last year showed that rising levels of greenhouse gases could triple the number of Category 5 hurricanes. (A link to this study and others appear below this column.)
Moreover, there's empirical evidence that hurricanes have already become more intense (but not more frequent). Nature magazine this summer reported a new study by Kerry Emanuel, a hurricane guru at M.I.T., indicating that by one measure hurricanes have almost doubled in intensity over the last 30 years.