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imported_Dutch
09-12-2004, 07:18 PM
Devastation linked to global warming

Gaby Hinsliff and Robin McKie
Sunday September 12, 2004
The Observer

Scientists are claiming that the unprecedented ferocity and frequency of the hurricanes that have battered the Caribbean this year can be blamed on one factor: the unexpectedly warm water that has been building up in the Atlantic over the past year.
But some leading US meteorologists reject the idea that this heating is in turn directly linked to global warming. The real villain is the great ocean conveyor belt that ferries warm water from the Equator to the poles, they say. Man-made climate change is a peripheral issue.

Every two or three decades, the conveyor belt picks up speed, scientists have discovered, and in doing so warms tropical waters. In turn, this heating alters atmospheric conditions around Africa, the origin of many major storm fronts. Greater storms are created and more make it to hurricane force.

According to Eric Blake of the National Hurricane Centre in Miami, sea surface temperatures are now 5C higher than recent averages and these have been directly responsible for spawning Hurricanes Ivan, Frances and Charley this summer.

The end result has been devastation. This is the first time in history that one season has produced two storms that have caused more than $1 billion in damage. Combined, Charley and Frances have resulted in insurance claims of more than $20bn. Ivan is likely to match this.

The meteorologists say there is more to come. The warming of the Atlantic that began last year is likely to linger for a couple of decades, creating large numbers of hurricanes.

This idea is backed by historical analysis which has shown that from the Forties to the early Sixties, hurricanes were relatively commonplace in the Caribbean. Then came relative tranquillity, when much of Florida's coastal population took up residence in the state. Now they face a return to the bad old days of tropical storms.

The images of Hurricane Ivan sweeping over Jamaica have added yet another image of climatic devastation in recent months. Although not directly linked to global warming, they have - along with pictures of wrecked harvests and summer deluges - intensified popular concerns about the climate. These fears will be directly tackled by Michael Howard this week when he gives a speech in which he will demand that Americans co-operate more closely on efforts to cut greenhouse gases. Howard will argue that the Prime Minister has failed to capitalise on his relationship with the White House by getting George Bush to sign the Kyoto pact.

'Like the war on terrorism or the drive for responsible free trade, climate change is an international issue that depends on international co-operation,' Howard will say. 'No one can opt out of the fight against global warming. That means persuading the Americans to join the battle against climate change.'

At the same time Tony Blair will make his own speech on global warming but will not directly criticise President Bush. However, he will not shy away from pointing out his well-known disagreement with the White House over global warming. 'It's obvious when it comes to issues like climate change that there are differences,' said a Downing Street source.

Blair has been repeatedly urged by ministers to make more of his differences with Bush to show voters he is capable of standing up to the Republican right on issues of principle. However, he has less room for manoeuvre than Howard, who has already burnt his bridges with the White House after a public spat prompted by the Bush administration's refusal to grant him photo opportunities with the President.

Jim H
09-12-2004, 11:29 PM
In 1964, 3 hurricanes struck Florida, so much for this piece of science. BTW looks like this one may be heading for the Mexican or Texas coast, Ivan's making for the Yucatan channel and a very warm Gulf of Mexico.

Meerkat
09-12-2004, 11:42 PM
A faster "conveyer belt" suggests less heating not more to me - the water is moved into and out of the tropical region faster so it is heated less.

Joe (SoCal)
09-13-2004, 12:06 AM
That's the idea Meerkat, with global warming some suggest the fresh water melting from the North polar caps is infiltrating the gulf stream creating the disturbance. Just a theory

Kev Smyth
09-13-2004, 01:31 AM
Global warming doesn't have anything to do with it- read a little on your own. Hurricane severity follows a roughly 100 year cycle, and we're about midway through the worst part of the deal. Another 10 years or so and things will calm down again.

Despite their elevated sense of importance, America's "boomers" have neither caused nor survived the worst this planet has to offer. :rolleyes: ;) But it is fun to add to the hysteria! :D

Oyvind Snibsoer
09-13-2004, 06:21 AM
As far as the northern part of the Gulf Stream* is concerned, measurements in the North Sea show that the current is more saline than before. This would seem to indicate that, although more polar ice may be melting and adding fresh weater to the sea, increased evaporation caused by increased sea temperature more than compensates for the added influx of fresh water.

Speculations that increased influx of fresh water in the North Atlantic current would hinder the formation of deep water in the Barents sea, thought to be the driving force behind the ocean conveyor, thus seem to be unfounded so far. Deep water is formed when the surface water is cooled, thus becoming more dense, sinks to the bottom and starts flowing south along the bottom of the ocean**. Increased salinity thus far seems to compensate for the higher water temperature.

* Or more correctly: the North Atlantic Current. The Gulf Stream branches just off Newfoundland, and the main continuation eastward is correctly known as the North Atlantic Current. The NAC gets about 20 Sverdrup (Sv) from the GS, and an additional 15 Sv from the Slope Water Current, a south moving current along the E coast of Canada, for a total estimated water flow of 35 Sv. 1 Sv = 1,000,000 m3/second.

** The natural vertical transportation of sea water is very slow, and is hardly measurable
with ordinary mechanical current measuring devices. The volume of water transported, however, is massive.

WWheeler
09-13-2004, 07:36 AM
Conveniently, for your hypothesi, Kev, we only have accurate data for the last 100 years. According to the graph below, it looks more like a 50 year cycle, which last peaked in the 50s. Note however, that the number of storms has risen to a new peak in the 2000s, and during the low point of the cycle the number of storms is at a higher point than during the previous cycle. Also, the intensity of storms (measured in wind speeds) has risen during the last 100 years.

http://www.atl.ec.gc.ca/weather/hurricane/climatology/images/frequencychart1a.png

NormMessinger
09-13-2004, 09:49 AM
Global warming bodes well for the English wine industry which, I read recently, is beginning to develop.

Bruce Hooke
09-13-2004, 12:40 PM
Originally posted by Jim H:
In 1964, 3 hurricanes struck Florida, so much for this piece of science. BTW looks like this one may be heading for the Mexican or Texas coast, Ivan's making for the Yucatan channel and a very warm Gulf of Mexico.The article is addressing the "unprecedented ferocity and frequency of the hurricanes...this year." With that in mind your comment that 3 hurricanes hit Florida in 1964 strikes me as fairly irrelevant information.

On the other side of the coin, trying to do comparisons, as the article does, based on property damage, also strikes me as a quite absurd. Property damage is obviously linked to:

- How much property there is in hurricane prone areas.
- Whether the hurricanes in question hit areas with high densities of valueable property.
- How well designed and built the property in the storm track was (note that this point and the previous one probably work in opposition to each other -- wealthy nations will have more valueable property but it will also probably be better built).
- How well prepared the property is -- we are doing much better in this area than we could 75 years ago when there was little or no warning in many cases.

None of the above have anything to do with the relationship between hurricanes and global warming so property damage is a pretty dicey basis for comparison. I'm betting that the real science behind this article used more scientifically valid comparisons.

Finally, for the record, there is little debate in the scientific community about the following two points:

1. That global warming/climate change is happening.

2. That it is partly due to natural patterns and partly due to the burning of fossil fuels -- both factors make substantial contributions to the changing global climate.

What is much harder to pin down and agree on are the specific impacts in any one part of the world -- this is where debates like the one addressed in this article come into play. However, we should not let such debates distract us from the basic facts of of the overall pattern and its causes.

WWheeler
09-13-2004, 01:01 PM
According to the data I seen on CBC, the intensity of the storms over the last 100 hundred years has been increasing, in terms of the wind speeds. Leaving aside the issue of property damage, which is a red herring, the question is whether this is due to a man-made phenomenon such as global warming, in which case we presumably can (and should) do something about it (and it will keep getting worse unless we do something about it), or alternatively, it's a natural phenomenon and there's nothing we can do about and let's just calm about the politics of it and just focus on riding it out. There is, of course, a third scenario, in that it's a natural phenomenon but we can do something about it, just as dumping silver nitrate or some such material into it.

Alan D. Hyde
09-13-2004, 01:03 PM
WWheeler, that graph you posted is about WEATHER.

To talk intelligently about matters of geology, geography, and climate, we require a MUCH longer record.

One hundred years is spit in the ocean.

Alan

WWheeler
09-13-2004, 01:12 PM
Alan, I'm not sure what your point is -- that because we don't have detailed meteorological records, we can't study long-term weather patterns? that global warming is actually a phenomenon of geology (volcanoes), rather than weather?

WWheeler
09-13-2004, 01:24 PM
http://www.giss.nasa.gov/research/observe/surftemp/2002fig1_s.gif

For comparison, how about this chart from NASA (Goddard Institute) for global temperature. Note the correlation between the mid-century peak in the 40's/50's, and the mid-century peak on the previous chart. This does not link hurricanes with man-made phenomenon, but with warming per se.

Alan D. Hyde
09-13-2004, 01:25 PM
CLIMATE describes long-term weather characteristics observable over decades, centuries and millenia.

A look at one hundred years doesn't tell us all that much. Are we looking at a long-term trend, something fundamental? or at a mere blip? What could a potential WWheeler biographer do in the way of a thorough, fair and accurate life of WWheeler after observing you for five seconds?

Geographic and geologic evidence help us look at the longer term: core borings in the earth, and in icecaps, study of ocean-bottom sedimentation, study of tree rings on long-lived species like bristlecone pines, etc. I don't think we know enough along these lines to draw any sound probative conclusions yet...

Alan

WWheeler
09-13-2004, 01:39 PM
Nonsense. Global climate is capable of rapid shifts according to well-documented sources of data such as glacial core samples, vegetation samples etc.

According to the following article, the global climate changed rapidly ie within a decade during the last age.


Can Global Climate Change Abruptly?

How fast will climate change in the future? How fast has climate changed in the past? Did climate change happen simultaneously around the world? Scientists from many countries are investigating such questions by studying the remains of plants in lakes and bogs. Seeds, needles, pollen and other plant parts are very well-preserved in lake muds because of the lack of oxygen in these sediments. By analyzing this detritus, layer by layer from bottom to top, the history of vegetation and climate can be extracted.

From analysis of these sediments, we now know that since the last ice age (21000 years ago), the climate has experienced at least one major climatic reversal to cold conditions, called the "Younger Dryas" for an arctic-alpine plant "Dryas" which populated Europe during the cold conditions. The flip to cold conditions is clearly seen in records throughout Greenlands and in Europe, and it occurred suddenly, within a decade.

http://www.giss.nasa.gov/research/intro/peteet_01/plot.GIF

Dorothy Peteet (NASA/GISS) has shown through field and laboratory work in New Jersey and Connecticut that the climate also flipped rapidly in southern New England, where a warm mixed boreal-hardwood forest was replaced suddenly by a cold boreal forest. Furthermore, her work on Kodiak Island, Aslaska, reveals that the climate there also reversed rapidly, and a lush coastal environment changed to a cold, dry tundra for almost a thousand years. Do other continents reveal this change? According to Peteet, the localities marked in the accompanying world map show evidence of this change. Future work will continue to pinpoint the geographic distribution, precise timing, and magnitude of the Younger Dryas. The final goal is to understand why this dramatic change happened in order to better understand our climate system.

Alan D. Hyde
09-13-2004, 01:41 PM
Or with sunspot activity.

Or with the number of female voters, globally.

Or with nude sunbathers per square foot of beachfront...

Causation is found in company with correlation, but it's by no means the entire story.

Otherwise, we'd be correct in concluding that a prevalence of snow tires in a vicinity CAUSES enhanced winter snowfall there.

Alan

Kev Smyth
09-13-2004, 01:48 PM
Originally posted by Alan D. Hyde:
Otherwise, we'd be correct in concluding that a prevalence of snow tires in a vicinity CAUSES enhanced winter snowfall there.

AlanI knew it!! I'm getting rid of my snow tires today- and writing my senator to suggest she sponsor legislation ridding the entire country of snow tires! :D ;)

I'll stand corrected on the 100 years of data being the complete cycle. It seems Bruce has the real take.

Alan D. Hyde
09-13-2004, 01:53 PM
WWheeler, the NONSENSE, Sir, is your own.

Show me, if you will, please, where I said that substantial and fundamental climate change cannot occur rapidly? I only said that weather conditions must be viewed and evaluated over the long term when drawing sustainable conclusions as to climate...

The sudden disappearance of the dinosaurs has long been attributed by many (though certainly not without disagreement and dispute by others) to a sudden change in climate. The large meteor that may have caused the Gulf of Mexico may have, thru several mechanisms, produced marked climate change. Even Krakatoa caused substantial, though short-term change.

Alan

Meerkat
09-13-2004, 01:57 PM
Originally posted by Alan D. Hyde:
Or with sunspot activity.

Or with the number of female voters, globally.

Or with nude sunbathers per square foot of beachfront...

AlanOr with rude Hydes masquarding as gentlemen.

Or with Jeckyls Hyding in trees.

Or with Alans (aliens?) Hyding their head in the sand.

:D

WWheeler
09-13-2004, 02:21 PM
"Sir" Imagine my surprise. It's been a while I've been called Sir outside of a fast food joint. (Anyway, hardly a mark of respect is it. These days, it seems to be synonymous with "pops" or "old man".)

Anyway, to use your definition, Mr. Hyde, I took your definition to mean that rapid changes would not qualify as climate change, since it is only observable in the short term. However, what we're talking about it the definition of what constitutes sustained changes.

The issue is, I think you will agree, whether a 100 year period is long enough to represent a sustained trend. Given the rapidity of climate change, it certainly looks that way to me, given the overall context of related long-term climate data.

Alan D. Hyde
09-13-2004, 02:27 PM
My point is that within the circumscribed period of one hundred years, we are talking about WEATHER changes, not about CLIMATE changes.

Respectfully,

Alan :D

WWheeler
09-13-2004, 02:37 PM
Agreed. And now to bring this discussion up to the present, here's a Hurricane Ivan projection from a Navy weather site.

http://www.nrlmry.navy.mil/htdocs_dyn/thumbnails/tc_thumbs/smal092004.04091300.gif

[ 09-13-2004, 03:40 PM: Message edited by: WWheeler ]