Hurricane scientists are divided.....

[dixiebreeze]

as to the cause of increasing tropical storms:


http://www.washtimes.com/world/20060529 ... -7254r.htm

[x-y-no]

Not usually a big fan of the Washington Times, but that was a well-written and balanced article.

Thanks for the link.

[wxmann_91]

There is absolutely no proof Global Warming is causing increased storms.

"The best available data shows that the number of Category 4 and 5 hurricanes globally has almost doubled since 1970," said Ms. Curry at Georgia Tech

Best available data for most storms around the world is based on satellite estimates. As shown with storms like Hugo and Opal, those estimates can be wrong.


And well later Dr. Landsea addresses this issue:

Regarding Georgia Tech, Mr. Landsea's argument is that primitive measuring techniques, here and especially in Asia, where most of the major tropical storms occur, made for imperfect data, and inaccurate "data sets" generate incorrect conclusions.

It is true that Atlantic hurricanes have been on the rise in both numbers and intensity, and one must realize the AMO in 2005 was in record territory. But - we have only 120 years of recorded history. Who says that with a record high AMO cycle (with cycles averaging about 20 yrs, so we only have had about six out of infinite amount of cycles in our database), that we cannot see a low one coming in around a decade?


Then it goes on to say...

"The key issue is whether you can distinguish a Category 4 from a Category 1 hurricane from satellite [data], the answer is almost always yes," she said.

I thought we were talking about Cat 4's and 5's? Can you distinguish a high-end Cat 3 and low-end 4 based on sat data alone? Look at the numbers of high-end 3's and low-end 4's in the past hundred years. Sure would make a huge difference.

Hurricanes are only one way to transfer heat from the tropics to the poles. To say global warming would cause an increase in hurricanes is a premature statement to make.

[Hybridstorm_November2001]

I know I know no political posts, but I just can't help saying this little bit:

Gore is an idiot! What qualifies him as an 'expert' (as many media outlets have been tooting him as) on 'Global Warming'? What meteorological training does he have? He is just another politician/celebrity trying to tell us all what to believe.

Sorry, but I just had to say it.

[x-y-no]

I know I know no political posts, but I just can't help saying this little bit:

I see ... you know the rules and you know you're breaking the rules but you're going to go ahead and do it anyway ...

[Hybridstorm_November2001]

Well it isn't really political. I didn't say he was a moron because he is a _________, for example. Though I thought I'd warn people that it could be seen as political, just in case.

[x-y-no]

Whatever.

There is such a thing as an informed layman. And I'm not going to agree that the public discourse should be restricted to some priesthood of certified experts.

My impression is Gore has put a lot of effort into understanding these issues. While he does get some things wrong (such as the claim that there's a consensus among hurricane experts that AGW is causing or will cause more frequent or intense hurricanes) he does a pretty good job overall of getting the facts right.

I won't get into his policy proposals, as that would certainly be political.

[Hybridstorm_November2001]

I think he is just doing it for personal gain quite frankly, and is twisting some of the facts to serve said purpose. At least that is the impression I received from watching his film. Just my two cents.

[x-y-no]

Not being a telepath, I don't know with complete certainty anyone's motivations but my own. Neither, I suspect, do you.

Therefore I prefer to confine such discussions to facts.

[Hybridstorm_November2001]

Well I can't say much more with out getting deeply into political topics (such as wedge issues, and political props for example), thus I'll leave it at that.

[ronjon]

The Emanuel and Webster papers are deeply flawed. Webster and others (2005) indicated that CAT 4-5 hurricanes had almost doubled between 1975-1989 and 1990-2003 globally and they attributed this to global warming. Phil Klotzbach from CSU recently published a paper that blows Webster's findings out of the water. He examined trends in CAT 4 & 5 storms over the last 20 years and found no global increase in intense storms. The increase in the atlantic basin since 1995 is due to the warm phase of the AMO (Atlantic Multidecadal Oscillation) which may last another 10 to 40 years. Globally, there have not been increases in CAT 4 or 5 storms over the last 20 years - yet ocean temps have increased 0.2 to 0.4 deg C. The database for West Pacific & Indian Ocean storm intensity is poor prior to the mid-1980s. The biggest hole in Webster's data is that he heavily relied upon the west Pacific ocean storms (which have the most intense hurricanes of all basins) to provide the majority of evidence to support his theory. However, the early record (1975-1989) is deeply flawed because the intensity forecasts were mostly based on Satellite estimated intensity's and the simple fact is that the Satellites weren't very good (low resolution, Dvorak method not refined till 1984) for estimating hurricane intensity back then.

Klotzbach's conclusions:

These findings are contradictory to the conclusions
drawn by Emanuel [2005] and Webster et al. [2005].
They do not support the argument that global TC
frequency, intensity and longevity have undergone
increases in recent years. Utilizing global ‘‘best track’’
data, there has been no significant increasing trend in
ACE and only a small increase (
10%) in Category 4–5
hurricanes over the past twenty years, despite an increase
in the trend of warming sea surface temperatures during
this time period.

http://hurricane.atmos.colostate.edu/In ... ch2006.pdf

[x-y-no]

The Emanuel and Webster papers are deeply flawed. Webster and others (2005) indicated that CAT 4-5 hurricanes had almost doubled between 1975-1989 and 1990-2003 globally and they attributed this to global warming. Phil Klotzbach from CSU recently published a paper that blows Webster's findings out of the water. He examined trends in CAT 4 & 5 storms over the last 20 years and found no global increase in intense storms.

I don't think one can fairly say that Klotzbach's work blew Webster's findings out of the water. The fact that the bulk of the apparent increase in Webster's findings occurred prior to 1981 was very clear in Webster's own published results - so obvious that it took very little time before several people (Klotzbach, Landsea etc.) pointed this out. Therefore, it's no surprise that Klotzbach's analysis of 1986-present came out as it did.

Now I'll certainly agree that Klotzbach's methodology looks good and that his result makes a persuasive argument for suspecting the accuracy of the earlier data (and thus Webster & Emmanuel's results) but that's a far cry from saying their paper is deeply flawed. It could be that it's Klotzbach's result which is flawed because the timeframe is so short.

Note, please, I'm not criticizing his choice of timeframe. He had ample justification based on the data quality questions regarding the earlier data. My point is only that Klotzbach did not prove Webster & Emmanuel wrong, rather he kept the issue undetermined.

The increase in the atlantic basin since 1995 is due to the warm phase of the AMO (Atlantic Multidecadal Oscillation) which may last another 10 to 40 years.

Can you list for me the physical phenomena which define the AMO? I ask this because I've never seen one despite the fact that definitive statements are regularly made about this purported cycle. I thought Dr. Gray had offered one relating to the rate of the thermohaline circulation, but as he mysteriously reversed himself on that definition earlier this year I'm not sure what to think about that anymore.

Globally, there have not been increases in CAT 4 or 5 storms over the last 20 years - yet ocean temps have increased 0.2 to 0.4 deg C. The database for West Pacific & Indian Ocean storm intensity is poor prior to the mid-1980s. The biggest hole in Webster's data is that he heavily relied upon the west Pacific ocean storms (which have the most intense hurricanes of all basins) to provide the majority of evidence to support his theory. However, the early record (1975-1989) is deeply flawed because the intensity forecasts were mostly based on Satellite estimated intensity's and the simple fact is that the Satellites weren't very good (low resolution, Dvorak method not refined till 1984) for estimating hurricane intensity back then.

I agree this is a fair issue to raise concerning the earlier data. I agree that this issue is serious enough to call their result into question. I don't agree that this proves their result was wrong.

Klotzbach's conclusions:

These findings are contradictory to the conclusions
drawn by Emanuel [2005] and Webster et al. [2005].
They do not support the argument that global TC
frequency, intensity and longevity have undergone
increases in recent years. Utilizing global ‘‘best track’’
data, there has been no significant increasing trend in
ACE and only a small increase (
10%) in Category 4–5
hurricanes over the past twenty years, despite an increase
in the trend of warming sea surface temperatures during
this time period.

http://hurricane.atmos.colostate.edu/In ... ch2006.pdf

I have no quarrel with Klotzbach's work. I read his paper carefully and his methodology seems impeccable to me. The only issue I have is the short timeframe. Unfortunately, this appears to me to be an issue that we really won't be able to answer until a significant amount of additional data is in, since I can think of no reliable way to improve the quality of the old data.

[Aslkahuna]

My view of this (and I follow Tropical Cyclones worldwide), is that given the shabby condition of the WPAC, Indian Ocean and Southern Hemisphere databases it is premature to assert that there is or is not a Global increase of intensities due to GW. Should it ever be possible to optimize all of the databases it should then be possible to pinpoint any trends if they exist.

Steve

[ronjon]

x-y-no wrote:

Note, please, I'm not criticizing his choice of timeframe. He had ample justification based on the data quality questions regarding the earlier data. My point is only that Klotzbach did not prove Webster & Emmanuel wrong, rather he kept the issue undetermined.

The increase in the atlantic basin since 1995 is due to the warm phase of the AMO (Atlantic Multidecadal Oscillation) which may last another 10 to 40 years.

Can you list for me the physical phenomena which define the AMO? I ask this because I've never seen one despite the fact that definitive statements are regularly made about this purported cycle. I thought Dr. Gray had offered one relating to the rate of the thermohaline circulation, but as he mysteriously reversed himself on that definition earlier this year I'm not sure what to think about that anymore.

Response:

I think Klotzbach proved that Webster's work was bogus. If global ocean temperatures have increased 0.2 to 0.4 deg C during the last 20 years, then why hasn't there been an increase in CAT 4 or 5s? Did global warming suddenly turn itself off the last 20 years? Or that storm intensity responded to the warming prior to the mid-1980s but since that time it doesn't? That seems to be a pretty large logic trap for global warming/intensity proponents.

On the AMO, the physical phenomenon is the long-term cyclic warming and cooling of a large pool of water in the North Atlantic ocean that occurs every 20 to 50 years. There are temperature records that document this oscillating temperature since the late-1800s. There also exist proxy data from tree ring analysis in the southeast US that dates back several centuries. Lastly, isotope data from Greenland chronicles this periodic warming and cooling in the North Atlantic Ocean back some 12,000 years.

It is true that the origins or the physical processes that govern the AMO are not well understood - but, this doesn't make the phenomenon invalid. Current theory is that deep ocean currents (i.e. the Atlantic thermohaline Circulation) transport higher salinity water from the tropical Atlantic to the Northern Atlantic ocean. The speed of this circulation dictates whether the water warms or cools (speeds up warmer, slows down cooler). Dave Enfield and others (2001) have an excellent paper on the AMO and its influence on climate for peninsula Florida and the continental US.

[Air Force Met]

My view of this (and I follow Tropical Cyclones worldwide), is that given the shabby condition of the WPAC, Indian Ocean and Southern Hemisphere databases it is premature to assert that there is or is not a Global increase of intensities due to GW. Should it ever be possible to optimize all of the databases it should then be possible to pinpoint any trends if they exist.

Steve

Agreed....and given the extremely small...small...small period of time in the geological time scale we are speaking of here...we don't have near enough info to draw a conclusion. The datasets...even as flawed as they are...exist on an even smaller scale of geological time. As someone pointed out in a previous post...what we are seeing now could be (and we don't know) 80% normal of the long-term (1000 years) cycle of intense storms. What we are seeing may just be a normal cycle...and we have people jumping all over themselves trying to blame it on something else....without even considering the POSSIBILITY that this is normal.

In science, you consider EVERY possibility before you draw your conclusions. It's kinda like that in Theology.

In Theology, we have Exegesis and Eisegesis. In Exegesis, you let the text (data) speak its truth to you. In Eisegesis, you go in with a bias...looking for your answer in the text (data). We have too many scientists who are conducting eisegesis...they are going in with a bias to find that global warming is causing XYZ (or that it is NOT)...and they are looking at the data using eisegesis.

That's not they way we should be going about it...but it is the way it is being done...and then depending on which side of the debate you fall on...you flock to those scientists and their "eisegetical" research instead of looking at emperical data.

[Valkhorn]

What I don't get is either way, what is so wrong with decreasing emmissions, pollutants, and finding renewable/alternative sources of energy?

[Air Force Met]

What I don't get is either way, what is so wrong with decreasing emmissions, pollutants, and finding renewable/alternative sources of energy?

Nothing is...I'm all for the above. The problem is...the developing world is going to surpass us in all of this very soon. They are going to be where we were 20 years ago...and a far greater scale.

[MGC]

It is an easy conclusion to claim that Cat-4&5 hurricanes world wide have doubled since 1970. Of course, I believe that claim to be false. Why? Satellites! It is nearly imposible for a Cat-4 or 5 to esape detection since the satellites have been watching the oceans 24/7/365 since the 1960's. This is simply a case of flawed data. Earth has been warming now for several hundred years, it is a natural occurance......MGC

[dixiebreeze]

What I don't get is either way, what is so wrong with decreasing emmissions, pollutants, and finding renewable/alternative sources of energy?

Nothing is...I'm all for the above. The problem is...the developing world is going to surpass us in all of this very soon. They are going to be where we were 20 years ago...and a far greater scale.

If they do it will be with American tax dollars i.e. foreign aid.

[HurryKane]

What qualifies him as an 'expert'

He invented the internet, doncha know!