WASHINGTON, May 19, 2008

Global Warming-Hurricane Link Questioned

U.S. Scientist Shifts Positions, Says Warmer Weather Will Reduce Number Of Hurricanes

  • In a normal year about 10 named storms form. Six become hurricanes and two become major hurricanes. On average, about five hurricanes hit the United States every three years.

    In a normal year about 10 named storms form. Six become hurricanes and two become major hurricanes. On average, about five hurricanes hit the United States every three years.  (AP Photo/NOAA)

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(AP)  Global warming isn't to blame for the recent jump in hurricanes in the Atlantic, concludes a study by a prominent federal scientist whose position has shifted on the subject.

Not only that, warmer temperatures will actually reduce the number of hurricanes in the Atlantic and those making landfall, research meteorologist Tom Knutson reported in a study released Sunday.

In the past, 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.

Ever 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 multi-decade cycle.

What makes this study different is 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 even 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 Sunday 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 United States and its neighbors - anywhere west of Puerto Rico - 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 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, Knutson's study says.

And Knutson said this study significantly underestimates the increase in wind strength. Some other scientists criticized his computer model.

MIT hurricane meteorologist Kerry Emanuel, while praising Knutson as a scientist, called his conclusion "demonstrably wrong" based on a computer model that doesn't look properly at storms.

Kevin Trenberth, a climate scientist, said Knutson's computer model is poor at assessing tropical weather and "fail to replicate storms with any kind of fidelity."

Trenberth, climate analysis chief at the National Center for Atmospheric Research in Boulder, Colo., said it is not just the number of hurricanes "that matter, it is also the intensity, duration and size, and this study falls short on these issues."

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.

But NOAA hurricane meteorologist Chris Landsea, who wasn't part of this study, praised Knutson's work as "very consistent with what's being said all along."

"I think global warming is a big concern, but when it comes to hurricanes the evidence for changes is pretty darn tiny," Landsea said.

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 May 22.

In a normal year about 10 named storms form. Six become hurricanes and two become major hurricanes. On average, about five hurricanes hit the United States every three years.

© MMVIII The Associated Press. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed.
Add a Comment See all 41 Comments
by erasmus81 May 20, 2008 4:09 PM EDT
well its one out of many that gore should be changing..now have gore made such an impression on you that you are doing something about global warming??

any solar panels on your house?

Posted by algoresarse at 02:50 AM : May 20, 2008

Yes, I am doing things about global warming. Everything that I can afford to do. There are a lot of things that people can do that cost very little.

Do I have solar panels? No, but I do have skylights. And just from having skylights, the furnace hasn''t come on for more than a few times in the past month or longer. And the temperatures outside have actually been a bit cool until recently.

What are you doing? Nothing, I bet, because you are one of those people still living in DENIAL. Right?

Reply to this comment
by algoresarse May 20, 2008 5:50 AM EDT
hawksprings, are you there?

Did you hear how Al Gore is making changes to his house? One of those changes is putting solar panels in his roof. That is one less thing you can complain about, right?:)

Posted by erasmus81 at 01:55 PM : May 19, 2008
+ report abuse

********

well its one out of many that gore should be changing..now have gore made such an impression on you that you are doing something about global warming??

any solar panels on your house?
Reply to this comment
by algoresarse May 20, 2008 5:47 AM EDT
1) I''''m Republican.
2) Those were NASA figures.
3) Scientists around the world agree with these figures. How is this a Democrat thing?

You have truly stepped off the deep end.

Posted by FloydZepp at 02:09 PM : May 19, 2008
+ report abuse

****************

you change your colors more often than you change underwear you d amn liberal..democrat..this story pretty much suggest that even nasa dont know shi*t..it is a democrat thing because ''global warming'' is something every liberal democrat is exploiting JUST GORE
Reply to this comment
by cfin5 May 20, 2008 1:52 AM EDT
There are 32,000 scientist who beg to differ Mr. Gore. They''ve all signed the Oregon Petition. Since plants breath Carbon Dioxide, why won''t vegetation flourish all the more to give us Oxygen and filter the air all the more?
Reply to this comment
by obamawhama May 19, 2008 9:56 PM EDT
one thing is for sure...scientists DOES NOT KNOW EVERYTHING.
Reply to this comment
by speakinup May 19, 2008 8:45 PM EDT
Watch Gore try to claim merit here.
Reply to this comment
by zykracosmos May 19, 2008 6:20 PM EDT
Agreed FloydZepp. Global Warming only becomes a political issue if you try to link Republicans to the propaganda released by fossil fuel industries like Exxon, who see their $40 billion in profits from last year as endangered. Although Republicans are historically pro-business, that doesn''t mean endorsing all mega-multinational corporations whose priorities are not necessarily good for America. A true Republican perspective would envision global warming as an issue that could stimulate American business ingenuity towards non-fossil resources, development of new products and technology for non-fossil energy supplies, and most importantly (from the GOP perspective) a reason to distance ourselves from foreign conflicts (traditionally a Republican strongpoint). This issue can and should be an issue that unites all Americans, regardless of whether their priorities as environmentalists or businessmen. It''s time we all rallied around ourselves and help put these changes on the fast track.
Reply to this comment
by erasmus81 May 19, 2008 4:55 PM EDT
hawksprings, are you there?

Did you hear how Al Gore is making changes to his house? One of those changes is putting solar panels in his roof. That is one less thing you can complain about, right?:)
Reply to this comment
by demslie May 19, 2008 4:39 PM EDT
NASA figures from 2006:

The result indicates that a strong underlying warming trend is continuing. Global warming since the middle 1970s is now about 0.6 degrees Celsius (C) or about 1 degree Fahrenheit (F). Total warming in the past century is about 0.80 C or about 1.40 F.

Posted by FloydZepp

Democrats like FloydZepp cand show these figures but that is not what causes the problem of the Global Warming Subject. Hurricane Katrina and Global Warming are blamed on George Bush. Al Gore went to Congress and Testified that Global Warming is not a Republican or Democrat issue. Later that week he exclaimed, "George Bush has Betrayed us on the Environment". Global Warming has always been used by Democrats as a political tool. And most Environmentalist (Tree Huggers who vote Democrat) Claim that all enviromental problems, as well as every problem in the world started on January 20th 2001.
Reply to this comment
by libh8er May 19, 2008 4:11 PM EDT
The earth, with a climate that has been changing for billions of years, has been trending warmer for about a hundred years now by a few degrees. Posted by lochlan at 11:16 AM : May 19, 2008

Actually, by about 1 degree C over the last hundred years.
Reply to this comment
by jimfinster May 19, 2008 3:48 PM EDT
ZykraCosmos:

Thanks for the insightful comments.

The new supercomputer at the National Center for Atmospheric Research should help. It''s called "Bluefire." Bluefire is one of the top 25 most powerful computers in the world, and it will triple NCAR''s computing power. Pretty neat - it is water cooled!

Reply to this comment
by zykracosmos May 19, 2008 3:21 PM EDT
A few observations of my own- While there is strong scientific evidence to link global warming with increased intensity of hurricanes (almost obvious, because hurricanes feed on warm water, and global warming has raised surface seawater temperatures), there are problems with predicting an increase in frequency for hurricanes or tropical storms. I had a conversation with Trenberth myself about this years ago, in suggesting global warming may increase the intensity of El Nino events (instead of an El Nino current 60 miles wide, you now have west to east currents that reach 600 miles in width). El Ninos now are so strong that they can actually reverse the Trade Winds, sending westerly winds across from the Pacific that provide formidable wind shear on any developing tropical storms. The storms get torn apart from the top down before they can develop into anything very powerful. This is exactly what happened in the El Nino year after the summer of Katrina. Climatology is a very complex science, and we still are trying to understand all the variables that need to be entered into a reliable computer model. We are much better at it than we were ten years ago, but it is definitely an evolving science.
Reply to this comment
by sistatee-2009 May 19, 2008 3:18 PM EDT
Global warming''s wrath? What BS. Get Al Gore''s fat _ss off that Gulfstream IV and watch the Earth cool down.
Reply to this comment
by lochlan-2009 May 19, 2008 3:15 PM EDT
I''''m and electrical engineer doing research. And I doubt you are even in science.

Posted by FloydZepp

I can tell, with words like "nucular". Tell me the site you would prefer.
Reply to this comment
by zykracosmos May 19, 2008 3:13 PM EDT
What you are witnessing is how science works and is meant to work. Real science is peer reviewed, and studies aren''t necessarily conclusive. No one should critize Knutson for his study. Computer modeling is an evolving field, and although his model is flawed, it deserves to be thoroughly reviewed as unbiased science. Trenberth is the reigning expert in climate modeling, and his comments are most important here. This is part of the process. Knutson''s work was at least serious enough to gain a comment from Trenberth. No one is threatened by the scientific process. You can''t disprove truth. The search for truth in science is based upon peer review, repetition, and conclusions based upon probability, not absolutes. Even the most established theories of all time are constantly under review. This process is what separates science from politic or philosophical debate.
Reply to this comment
by questionnews May 19, 2008 2:33 PM EDT
And what sort of education level do you have again. A degree in NASCAR?


Posted by FloydZepp

I don''''t like to brag, but I am a nuclear engineer.

Posted by lochlan at 11:28 AM : May 19, 2008

Careful there FloydZepp!! You might want to just stay with your normal insults & flee without a scentific response.
Reply to this comment
by lochlan-2009 May 19, 2008 2:29 PM EDT
FloydZepp-

And you?
Reply to this comment
by lochlan-2009 May 19, 2008 2:28 PM EDT
And what sort of education level do you have again. A degree in NASCAR?


Posted by FloydZepp

I don''t like to brag, but I am a nuclear engineer.
Reply to this comment
by lochlan-2009 May 19, 2008 2:27 PM EDT
2005 U.S. Senate Bill 517 and U.S. House Bill 2995
U.S. Senate Bill 517[15] and U.S. House Bill 2995[16] were two laws proposed in 2005 that would have allowed experimental weather modification by artificial methods, established a Weather Modification Operations and Research Board, and implemented a national weather modification policy. Neither ever became law.
Reply to this comment
by lochlan-2009 May 19, 2008 2:16 PM EDT
All right global warming nuts, let me get this straight.

The earth, with a climate that has been changing for billions of years, has been trending warmer for about a hundred years now by a few degrees. And now you people want to stop it from getting any warmer. The whole planet, you want to keep it at its current temperature, is that right?

CO2 is the greenhouse gas you are talking about reducing correct? Just Facts From Wikipedia (for those with a brain):

Nitrogen 78.0842%
Oxygen 20.9463%
Argon 0.93422%
-- Carbon dioxide 0.03811%
Water vapor about 1%
Other 0.002%

"Existence of the greenhouse effect as such is not disputed. Naturally occurring greenhouse gases have a mean warming effect of about 33 0C (59 0F), without which Earth would be uninhabitable.[24][25] On Earth, the major greenhouse gases are water vapor, which causes about 36%u201370% of the greenhouse effect (not including clouds); carbon dioxide (CO2), which causes 9%u201326%; methane (CH4), which causes 4%u20139%; and ozone, which causes 3%u20137%."

"The atmospheric concentrations of CO2 and CH4 have increased by 31% and 149% respectively since the beginning of the industrial revolution in the mid-1700s."
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