Study finds strong warming tie to hurricanes (except that hurricans aren't getting any stronger)

MSNBC ^ | 6/22/06

[presidio9]

Global warming accounted for about half of the extra hurricane-fueling warmth in Atlantic waters off the United States in 2005, while natural cycles were smaller factors, according to a study released Thursday by the National Center for Atmospheric Research.

"The global warming influence provides a new background level that increases the risk of future enhancements in hurricane activity," co-author Kevin Trenberth wrote in the study.

A statement issued by the center said that the study "contradicts recent claims that natural cycles are responsible for the upturn in Atlantic hurricane activity since 1995. It also adds support to the premise that hurricane seasons will become more active as global temperatures rise."

While researchers agree that the warming waters fuel hurricane intensity, they have been uncertain whether Atlantic waters have warmed because of a natural, decades-long cycle, or because of longer-term global warming.

The study found that during much of last year's hurricane season, which runs from June 1 to Nov. 30, sea-surface temperatures in Atlantic waters where many hurricanes form were a record 1.7 degrees F above the 1901-1970 average.

Comparing the Atlantic data to worldwide data since the early 20th century, the researchers calculated that global warming explained about 0.8 degrees of this rise.

The 2004-05 El Nino ocean cycle accounted for about 0.4 degrees, they calculated, while the 60-80 year natural cycle was thought to explain less than 0.2 degrees of the increase, according to Trenberth. The remainder is due to year-to-year variability in temperatures.

The center said the researchers "subtracted the global trend from the irregular Atlantic temperatures — in effect, separating global warming from the Atlantic natural cycle."

[capt. norm]

Note that hurricane-like activity has increased on Jupiter as well.

Our ultimate source of energy, the Sun, is for some reason, left out of the discussion.

[CedarDave]

A second red spot has been observed on the planet, no doubt due to all the SUV's driven by Jovians.

[GovernmentShrinker]

Okay. If global warming causes stronger hurricanes, and hurricanes aren't getting stronger, then that proves there's no global warming, right? See, I can do "science" (at least up to enviro-alarmist standards).

[capt. norm]

Algore reminds me of the primitive witch doctors or medicine men who tried to gain dominion over their people by claiming to have special knowledge and special powers.

He is essentially doing the same thing with "global warming".

[GovernmentShrinker]

Our ultimate source of energy, the Sun, is for some reason, left out of the discussion.

Probably because it's been documented that there's been a long period of significantly above-average sunspot activity, that is quite likely contributing to the warming. Mentioning that wouldn't fit well with the article's thesis.

[cogitator]

I think that the accurate characterization of the studies is: global warming causes increased sea surface temperature, which in turn leads to an increased probability of more Category 4 and 5 hurricanes compared to the probability distribution with no enhanced SST.

[presidio9]

Say that's pretty interesting. Now how come we aren't getting more category 4-5 hurricanes?

[cogitator]

Now how come we aren't getting more category 4-5 hurricanes?

Hurricanes Are Getting Stronger, Study Says (badly worded title!)

Quote: "The number of Category 4 and 5 hurricanes worldwide has nearly doubled over the past 35 years, even though the total number of hurricanes has dropped since the 1990s, according to a study by researchers at the Georgia Institute of Technology and the National Center for Atmospheric Research (NCAR). The shift occurred as global sea surface temperatures have increased over the same period. The research will appear in the September 16 issue of the journal Science, published by the AAAS, the science society, the world’s largest general scientific organization."

What was your question again?

[presidio9]

The numbers of hurricanes of particular intensities are incorrect. Go ahead and add them up for yourself if you don't believe me. Additionally, a real scientist would not simply pick two consecutive 15yr periods and use that to claim that this proves hurricanes are increasing. Your junk scientists really mean that that there were more hurricanes in the fifteen years between 1990-2004 than there were in the fifteen years between 1975-1989. That is an increase of sorts, but since the Earth is billions of years old, it is not an indication that high intensity hurricanes are increasing.

[cogitator]

The numbers of hurricanes of particular intensities are incorrect. Go ahead and add them up for yourself if you don't believe me.

While it might be an interesting exercise to determine if the number of Cat 4 and Cat 5 ATLANTIC hurricanes has increased or decreased over the time period of the database (feel free to post the numbers if you want to), this would not refute the Webster study meaningfully, because it was a GLOBAL study. I doubt that there is a reasonable assessement available of global hurricane intensities since 1900, as many Pacific hurricanes would have been undetected/unreported.

Your junk scientists really mean that that there were more hurricanes in the fifteen years between 1990-2004 than there were in the fifteen years between 1975-1989. That is an increase of sorts,

Well yes it is.

since the Earth is billions of years old, it is not an indication that high intensity hurricanes are increasing.

The age of the Earth is somewhat inconsequential to an evaluation of whether increasing SST encourages the formation of larger numbers of Cat 4 - Cat 5 hurricanes, considering that there's no way to make an assessment of hurricane frequency for prehistorical periods.