With America's eyes fixed on Hurricane Katrina's destructive force, we naturally look for an explanation or a cause. Eyes in times past would have roved upward to the heavens; now they fix themselves firmly on science, eager to hear explanations of a link between global warming and impressive natural disasters.
There are many out there ready to indulge this notion and use a terrible calamity to further their own political ends. They glibly contend hurricanes are exactly the sort of result we can expect if we keep contributing to global warming and that New Orleans has reaped the fruit of our irresponsibility.
Chief among this new band of augurs is Robert F. Kennedy Jr. who has directly blamed President Bush and Mississippi Gov. Haley Barbour for the destruction caused by Katrina. He is working in tandem with self-proclaimed expert Ross Gelbspan who suggests the link between global warming and the disaster is so clear the hurricane should be re-named "Global Warming."
Both cite Kerry Emanuel of the Massachusetts Institute of Technology, who recently published a paper arguing there is a clear correlation between climate change and hurricanes. As man warms the oceans, the argument says, hurricanes intensify and cause greater damage. The result: More houses and property destroyed and damaged and higher insurance costs.
Yet there is much evidence this is all just hot air. The alarmists notably fail to cite the cyclical nature of hurricane behavior. From the late 1920s to the 1960s there was high hurricane activity. If global warming is to blame for more hurricanes now, what caused the last cycle?
As leading hurricane scientist William Gray argues, North Atlantic surface temperatures vary naturally. They were cool from the 1970s to the 1990s, but warm during the last period of intense hurricane activity from the late '20s to the 1960s. He says, "Instead of seeing a long-term trend up or down, we do see a quasicyclic multidecade regime that alternates between active and quiet phases for major Atlantic hurricanes on the scale of 25-40 years each."
The global warming-hurricane theory is flawed; Mr. Emanuel and others have tracked the buildup of a natural cycle, not discovered a linear trend. It is apparent the intuitive ideas forwarded by the likes of Mr. Emanuel inevitably result from classic "cherry picking" science. Given that patterns in hurricanes seem driven by 20-40 year cycles, to draw solid conclusions from a period that began in the 1970s and neglect prior natural patterns is a bit like staying up from 5 a.m. to 9 a.m. and finding there is a trend the Earth is getting brighter.
Further, global warming alarmists contradict their own scientific case. If, as the models suggest, warming occurs mostly toward the poles, the north-south temperature gradient should narrow. If this is so, the frequency and intensity of hurricanes should diminish. If they believe their own science, the alarmists should argue global warming is reducing hurricanes.
And there is no answer forthcoming why, if global warming is to blame, its results seem to specifically target the Atlantic and ignore the Pacific and Indian oceans.
It is equally misleading to use rising property damage costs to suggest increased hurricane intensity. It is true there is more property destroyed in hurricanes now than 50 years ago. This is not, however, due to hurricanes getting stronger but of more property development being in their paths.
According to Christopher Landsea of the National Oceanic and Atmospheric Administration, "Southeast Florida including metropolitan Miami went 42 years (1950-1992) between strikes by intense hurricanes. During that time, the population increased by more than 600 percent."
Even if hurricane intensity declined, economic damage would rise. In a 1996 paper titled "Downward trends in the frequency of intense Atlantic hurricanes during the past five decades," Mr. Landsea argued a "large portion of [the] immense toll" of high-profile hurricanes "is due to the property development and population increases along the U.S. coastal states."
There is little or no rigorous scientific evidence global warming has contributed anything significant to the recent strong hurricane seasons, yet alarmists -- including some scientists who should know better -- continue making the link.
Even Kerry Emanuel told the British newspaper the Independent he didn't think Katrina could be blamed on global warming. In days past, Katrina would have been called an Act of God. Today some, for the basest political reasons, want to call it an act of man. Our forefathers were nearer the truth.