Hurricanes and Global Warming....

The press seems to love hurricanes - seeing them as proof of global warming. But is it? Here's a nice piece from the Cato Institute.

Here's the simplistic argument. Hurricanes require warm water. Global warming means more of that. Therefore, more hurricanes.

The fact is that there's plenty of warm water for hurricanes every year--virtually the entire tropical ocean is hot enough, and yet there are only about 10 per year in the Atlantic. The real research question on these storms is not why there are so many but, rather, why there are so few, given the massive expanse of warm water available to them?

And here's the real scientific inconvenience in Blair's story. The planet warmed slightly--much less than forecast by people like King--in the last half of the last century, but while that happened, maximum winds in Atlantic hurricanes DECLINED significantly.

Yep. As shown by scientist Chris Landsea of the National Oceanic and Atmospheric Administration, maximum winds measured by hurricane-hunter aircraft over the last 50 years have declined significantly.

Further, there's a logical (if lawyerly) argument that pins this salutary change on global warming. It goes like this: Atlantic hurricanes are much more delicate than their destruction suggests. One thing they cannot tolerate is a west wind blowing into them because it wrecks their symmetry. As a result, their maximum winds decline.

El Niño--another climate hype machine--generates precisely this type of wind over the Atlantic. That's why, in El Nino years, the forecast is for a weak hurricane season.

In the latter part of the last century, there were an unusual number of El Niño years compared to previous decades. Some scientists (like David King) claim that global warming is increasing the frequency of El Nino. But if that's the case, then global warming would be responsible for the decline in maximum hurricane winds.

How much could that be worth? The decline has been about 15 mph since 1950. That's not a small number because the force of a hurricane's wind goes up with the square of the velocity. In the high Category Three/low Four range, this change reduces the power by 25 percent. Given that the U.S. experiences about 15 strong hurricanes every decade, and that the average cost is now about $5 billion for one of those hits, you could, if you buy the El Niño argument (I don't but some others do), thank global warming saving about $13 billion per decade.

These numbers won't stop the hype machine on hurricanes. But you'd think that Great Britain's science adviser would have been sufficiently well informed that he would have kept his prime minister from asking John Kerry to sow the whirlwind.