Scientist no longer sees hurricane-warming link
(My comment: careful, this is another computer model)
ASSOCIATED PRESS
Global warming isn't to blame for the recent jump in hurricanes in the Atlantic, according to a study by a prominent federal scientist whose position has shifted on the subject.
Not only that, higher temperatures will actually reduce the number of hurricanes in the Atlantic and those making landfall, research meteorologist Tom Knutson reported in a study released yesterday.
In the past, Mr. Knutson has raised concerns about the effects of climate change on storms. His new paper has the potential to heat up a simmering debate among meteorologists about current and future effects of global warming in the Atlantic.
Since Hurricane Katrina in 2005, hurricanes have often been seen as a symbol of global warming's wrath. Many climate change experts have tied the rise of hurricanes in recent years to global warming and hotter waters that fuel them.
Another group of experts, those who study hurricanes and who are more often skeptical about global warming, say there is no link. They attribute the recent increase to a natural multidecade cycle.
What makes this study different is Mr. Knutson, a meteorologist with the National Oceanic and Atmospheric Administration's fluid dynamics lab in Princeton, N.J.
He has warned about the harmful effects of climate change and has complained in the past about being censored by the Bush administration on past studies on the dangers of global warming.
He said his new study, based on a computer model, argues "against the notion that we've already seen a really dramatic increase in Atlantic hurricane activity resulting from greenhouse warming."
The study, published online yesterday in the journal Nature Geoscience, predicts that by the end of the century, the number of hurricanes in the Atlantic will fall by 18 percent.
The number of hurricanes making landfall in the U.S. and its neighbors will drop by 30 percent because of wind factors.
The biggest storms — those with winds of more than 110 mph — would only decrease in frequency by 8 percent. Tropical storms, those with winds between 39 and 73 mph, would decrease by 27 percent.
It's not all good news from Mr. Knutson's study, however. His computer model also forecasts that hurricanes and tropical storms will be wetter and fiercer. Rainfall within 30 miles of a hurricane should jump by 37 percent, and wind strength should increase by about 2 percent, Mr. Knutson's study says.
Mr. Knutson said this study significantly underestimates the increase in wind strength. Some other scientists criticized his computer model.
Massachusetts Institute of Technology hurricane meteorologist Kerry Emanuel, while praising Mr. Knutson as a scientist, called his conclusion "demonstrably wrong" based on a computer model that doesn't look properly at storms.
Kevin Trenberth, climate analysis chief at the National Center for Atmospheric Research in Boulder, Colo., said Mr. Knutson's computer model is poor at assessing tropical weather and "fail to replicate storms with any kind of fidelity."
Mr. Knutson acknowledges weaknesses in his computer model and said it primarily gives a coarse overview, not an accurate picture on individual storms and storm strength. He said the latest model doesn't produce storms surpassing 112 mph.
Hurricane season starts June 1 in the Atlantic, and a Colorado State University forecast predicts about a 50 percent more active than normal storm season this year. NOAA puts out its own seasonal forecast on Thursday. |
