EDIT
In the end, however, Bush held firm. Washington vetoed all references to mandatory emissions cuts or timelines, and the climate-change issue was overshadowed by African debt relief, which had been publicized by Bob Geldof's Live 8 concerts. "There were no tough targets at Gleneagles because we would not have got all signatures on the document," says King, who adds, "We might well have" gotten seven—that is, every nation but the U.S. The farthest the G-8 leaders went—and even this required a battle, says King—was to include a sentence that read, in part, "While uncertainties remain in our understanding of climate science, we know enough to act now." But seven weeks later, nature acted first, and it was the United States she hit.
No one can say for sure whether global warming caused Hurricane Katrina, which slammed into the Gulf Coast on August 29, 2005. But it certainly fit the pattern. The scientific rule of thumb is that one can never blame any one weather event on any single cause. The earth's weather system is too complex for that. Most scientists agree, however, that global warming makes extra-strong hurricanes such as Katrina more likely because it encourages hot oceans, a precondition of hurricane formation. "It's a bit like saying, 'My grandmother died of lung cancer, and she smoked for the last 20 years of her life—smoking killed her,'" explains Kerry Emanuel, a professor at the Massachusetts Institute of Technology who has studied hurricanes for 20 years. "Well, the problem is, there are an awful lot of people who die of lung cancer who never smoked. There are a lot of people who smoked all their lives and die of something else. So all you can say, even
the evidence statistically is clear connecting lung cancer to smoking, is that upped her probability."
Just weeks before Katrina struck, Emanuel published a paper in the scientific journal Nature demonstrating that hurricanes had grown more powerful as global temperatures rose in the 20th century. Now, he says, by adding more greenhouse gases to the earth's atmosphere, humans are "loading the climatic dice in favor of more powerful hurricanes in the future."
But most Americans heard nothing about Hurricane Katrina's association with global warming. Media coverage instead reflected the views of the Bush administration—specifically, the National Oceanic and Atmospheric Administration, which declared that the hurricane was the result of natural factors. An outcry from N.O.A.A.'s scientists led the agency to backtrack from that statement in February 2006, but by then conventional wisdom was set in place. Post-Katrina New Orleans may eventually be remembered as the first major U.S. casualty of global warming, yet most Americans still don't know what hit us.
EDIT
http://www.vanityfair.com/commentary/content/articles/060424roco03