Recent Increase in Hurricane Intensity Related to Climate Change, Scientists Conclude
The Epoch Times | Recent Increase in Hurricane Intensity Related to Climate Change, Scientists Conclude
By Nicholas Zifcak
The Epoch Times Washington D.C. Staff Oct 10, 2005
Nasa Image/AFPThere is a clear link “between increasing hurricane events, intensity, and global warming,” concluded Dr. Judith Curry Tuesday while speaking at the World Bank. Dr. Curry and Dr. Peter Webster presented the findings of the article they, G.J. Holland, and H.R. Chang published in the September 16th issue of Science, a national scientific journal. “We haven’t proved this beyond a reasonable doubt, but we have preponderance of evidence,” she continued.
The authors based their research on global hurricane data from 1970 to 2004. Hurricanes are classified on a scale of 1 to 5 from depending on their wind speed, with 1 being the slowest and 5 the fastest. Over the last thirty-five years, category 1 hurricanes have decreased, while categories 2 and 3 have remained stable. But Category 4 and 5 hurricanes have grown from forty per year in the 1970s to ninety per year in the 1990s and has maintained that rate up through the present. Hurricane Katrina was a category 4 hurricane when it struck Louisiana, though off shore it reached category 5.
To evaluate possible causes of the hurricanes Dr. Curry and her colleagues looked for correlations between rising global sea surface temperatures and the frequency and intensity of hurricanes.
“There are several ingredients to get a hurricane. Sea surface temperature is absolutely necessary,” stated Dr. Curry. Other important factors are wind patterns and air moisture. She indicated that the Gulf of Mexico had warm surface water this year, warm water a couple hundred feet deep. When the powerful winds of the hurricane churn this warm water intensify the hurricane. In this warm Gulf water Dennis, Emily, Katrina, and Rita developed into category 4 and 5 hurricanes. “This is the greatest cluster of storms we have seen” Mr. Webster explained, “this is the first time category 4 or 5 storms have been in the Gulf this early in the year.”
Sea surface temperature increases of 0.5 degrees have been measured across the globe in all ocean basins. But the dramatic increase in hurricane number and intensity seen in the North Atlantic is not common to all oceans. Most basins have seen only an increase in hurricane intensity (as indicated above). If global increased hurricane intensity correlates with increasing sea surface temperature, then why is the sea surface temperature rising? Rising sea surface temperature is one aspect of the general global warming effect. While it is difficult to deny data showing rising sea surface temperatures across the globe, the exact cause is yet to be isolated. Dr. Curry has, however, made her conclusions as to the cause of rising sea surface temperatures, namely increasing pollution of greenhouse gases such as carbon dioxide (CO2). She cautioned that the “increased hurricane intensity represents the greatest near term socioeconomic impact of greenhouse warming.”
Some have claimed that the recent upswing in land falling hurricanes is related to a larger cycle of hurricane patterns. But global data shows that the number of land falling hurricanes in the U.S. is 0.2% of global hurricanes. U.S. land falling hurricanes can’t “explain anything about global variability.” To understand global weather shifts, global weather patterns must be examined.
By Nicholas Zifcak
The Epoch Times Washington D.C. Staff Oct 10, 2005
Nasa Image/AFPThere is a clear link “between increasing hurricane events, intensity, and global warming,” concluded Dr. Judith Curry Tuesday while speaking at the World Bank. Dr. Curry and Dr. Peter Webster presented the findings of the article they, G.J. Holland, and H.R. Chang published in the September 16th issue of Science, a national scientific journal. “We haven’t proved this beyond a reasonable doubt, but we have preponderance of evidence,” she continued.
The authors based their research on global hurricane data from 1970 to 2004. Hurricanes are classified on a scale of 1 to 5 from depending on their wind speed, with 1 being the slowest and 5 the fastest. Over the last thirty-five years, category 1 hurricanes have decreased, while categories 2 and 3 have remained stable. But Category 4 and 5 hurricanes have grown from forty per year in the 1970s to ninety per year in the 1990s and has maintained that rate up through the present. Hurricane Katrina was a category 4 hurricane when it struck Louisiana, though off shore it reached category 5.
To evaluate possible causes of the hurricanes Dr. Curry and her colleagues looked for correlations between rising global sea surface temperatures and the frequency and intensity of hurricanes.
“There are several ingredients to get a hurricane. Sea surface temperature is absolutely necessary,” stated Dr. Curry. Other important factors are wind patterns and air moisture. She indicated that the Gulf of Mexico had warm surface water this year, warm water a couple hundred feet deep. When the powerful winds of the hurricane churn this warm water intensify the hurricane. In this warm Gulf water Dennis, Emily, Katrina, and Rita developed into category 4 and 5 hurricanes. “This is the greatest cluster of storms we have seen” Mr. Webster explained, “this is the first time category 4 or 5 storms have been in the Gulf this early in the year.”
Sea surface temperature increases of 0.5 degrees have been measured across the globe in all ocean basins. But the dramatic increase in hurricane number and intensity seen in the North Atlantic is not common to all oceans. Most basins have seen only an increase in hurricane intensity (as indicated above). If global increased hurricane intensity correlates with increasing sea surface temperature, then why is the sea surface temperature rising? Rising sea surface temperature is one aspect of the general global warming effect. While it is difficult to deny data showing rising sea surface temperatures across the globe, the exact cause is yet to be isolated. Dr. Curry has, however, made her conclusions as to the cause of rising sea surface temperatures, namely increasing pollution of greenhouse gases such as carbon dioxide (CO2). She cautioned that the “increased hurricane intensity represents the greatest near term socioeconomic impact of greenhouse warming.”
Some have claimed that the recent upswing in land falling hurricanes is related to a larger cycle of hurricane patterns. But global data shows that the number of land falling hurricanes in the U.S. is 0.2% of global hurricanes. U.S. land falling hurricanes can’t “explain anything about global variability.” To understand global weather shifts, global weather patterns must be examined.
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