Tuesday, August 30, 2005

Global warming and Mother Nature

Rich Lowry wrote in National Review Online If cable TV had existed in 1886, everyone in the U.S. might have been whipped into a hurricane panic. A record seven hurricanes made landfall that year, including a Category 4 storm that hit Texas and would have had on-the-spot cable newscasters dramatically fighting the wind to deliver their reports. All during the 1890s, reporters could have done the same along the Atlantic seaboard, as it was hammered by more powerful hurricanes than it would be in any decade except the 1950s. Hurricane Katrina, which slammed the Gulf Coast and got eyewall-to-eyewall media coverage, is sure to increase the sense that there is an epidemic of hurricanes (along, of course, with an epidemic of shark attacks and missing blond girls). Which inevitably raises the question: "What can we do about it?" For some scientists and activists — working on the assumption that anything they don't like must be caused by industrial emissions — the answer is stop global warming. There is hardly an undesirable natural event, from wildfires to hurricanes, that former Vice President Al Gore hasn't blamed on global warming. As if it weren't for fossil-fuel emissions, the weather would always be predictable and pleasant. An outfit called Scientists and Engineers for Change put up a billboard in Florida before last year's presidential election stating it starkly: "Global warming = Worse hurricanes. George Bush just doesn't get it." Ah, yes: Why are Bush and the neocons focused on the war in Iraq, when there is a very real threat to the U.S. they should be addressing in the waters of the Atlantic? Has global warming increased the frequency of hurricanes? One of the nation's foremost hurricane experts, William Gray, points out that if global warming is at work, cyclones should be increasing not just in the Atlantic but elsewhere, in the West Pacific, East Pacific, and the Indian Ocean. They aren't.

There was a Tsunami, but you can't blame an underseas earthquake on global warming, at least if you have any sense.
The number of cyclones per year worldwide fluctuates pretty steadily between 80 and 100. There's actually been a small overall decline in tropical cyclones since 1995, and Atlantic hurricanes declined from 1970 to 1994, even as the globe was heating up. It seems that Atlantic hurricanes come in spurts, or as the National Oceanic and Atmospheric Administration puts it in more technical language, "a quasi-cyclic multi-decade regime that alternates between active and quiet phases." The late 1920s through the 1960s were active; the 1970s to early 1990s quiet; and since 1995 — as anyone living in Florida or Gulfport, Miss., can tell you — seems to be another active phase.

But if hurricanes aren't more frequent, are they more powerful? Warm water fuels hurricanes, so the theory is that as the ocean's surface heats up, hurricanes will pack more punch. An article in Nature — after questionable jiggering with the historical wind data — argues that hurricanes have doubled in strength because of global warming. Climatologist Patrick Michaels counters that if hurricanes had doubled in their power it would be obvious to everyone and there would be no need to write controversial papers about it. Indeed, if you adjust for population growth and skyrocketing property values,
Including a LOT more building of expensive houses right on the ocean, as well as in areas subject to major forest fires, mudslides, earquakes, etc.
hurricanes don't appear to be any more destructive today. According to the work of Roger Pielke of the University of Colorado, of the top five most destructive storms this century, only one occurred after 1950 — Hurricane Andrew in 1992. An NOAA analysis says there have been fewer Category 4 storms throughout the past 35 years than would have been expected given 20th-century averages.

None of this data matters particularly, since proponents of global warming will continue to link warming with hurricanes. It generates headlines in a way that debates about tiny increments of warming don't. And it feeds a conceit that is oddly comforting: that whatever is wrong with the world is caused by us and fixable by us. Alas, it's not so. Mother Nature can be a cruel and unpredictable mistress, and sometimes all we can do is head for the high ground.

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