Posted on 02/24/2005 11:55:07 AM PST by Einigkeit_Recht_Freiheit
LONDON — The current retreat of ice shelves in the Antarctic due to global warming is nothing new -- but this time the problem is manmade and therefore potentially more serious, according to research released Wednesday.
Writing in the latest issue of the journal "Geology," British scientists said a survey had shown that ice shelves had retreated thousands of years ago as a result of rising air and ocean temperatures.
"What this tells us is that ice shelves don't just break up because they get too big -- as the global warning skeptics argue," said Dominic Hodgson, a scientist with the British Antarctic Survey and one of the leading investigators.
He said previous periods of warming -- about 9,500 years ago and some 2,000 years to 4,000 years ago -- were caused by natural causes, including the ending of ice ages, rather than man's emissions and the ice shelves had been able to reform.
"This time, the problem is man-made and if we don't take steps, the damage will be worse," he said. "There is no room for complacency."
The study, by scientists from the universities of Durham, Edinburgh and from the British Antarctic Survey, or BAS, said the George VI Ice Shelf on the Antarctic Peninsula is the first to show that a currently 'healthy' ice shelf experienced an extensive retreat about 9,500 years ago, more than anything seen in recent years.
BAS scientists Carol Pudsey and Jeff Evans reported that the Prince Gustav Ice Shelf, which collapsed in 1995, had also collapsed several thousand years ago.
This, along with the recent collapse of other ice shelves like Larsen B, has been put down to an overall increase in temperatures caused by damage to the ozone layer that protects the earth from the sun.
The study is particularly relevant for other surveys on the West Antarctic Ice Sheet where scientists have found that a relatively warm current, Circumpolar Deep Water, is causing high melt rates on the underside of an ice shelf in Pine Island Bay.
The gradual removal of this ice shelf may be causing the glaciers inland to flow faster, which could lead to enhanced drainage of part of the West Antarctic Ice Sheet, and a rise in sea level.
The BAS says that over the past 900,000 years, there has been an average of 280 parts per million of carbon dioxide in the atmosphere, one of the main causes of global warming. In the period since the Industrial Revolution, and particularly in recent years, that has risen to 350 parts per million.
The scientists analyzed sediments from the bottom of a freshwater lake close to the edge of the present George VI Ice Shelf. The results revealed that about 9,500 years ago the shelf retreated, allowing the sea to flood into the lake. The ice shelf didn't reform until 1,500 years later, and has been present ever since.
Ice shelves are formed when glaciers flow into the sea and freeze, then coalesce with other frozen flows.
But, this article is makes me seriously rethink my understanidng of the situation.
Somehow, they are saying this all happened before, but pay no attention to the man behind the curtain.
The risk is greater than the sacrifice, but what if the sacrifice is for naught. . . .
A climatologist I'm not, but do you notice how the first thing they do now, always, is to address why the new data disproves skeptics? Remember when, a few years ago, most articles on the subject maintained there were no skeptics? If they're so sure of themselves, why does this seem so much like a rearguard action?
Global Warming WILL change things around. We can kiss the boardwalk in Venice Ca. goodbye but then it will be a better world without it. Coastlines will change. Venice Italy is probably history. It won't be the end of the world. Alaska will be a much more inviting place. Change is good. It'll be fun.
This is not a thread about homosexuality. At least I did not think it was.
And we know this how? The 'scientist' says because the hockey stick non-sense shows this. They assume the earth's tempreture had been constant then evil man came along and upset our perfect little equilibrium.
But, this article is makes me seriously rethink my understanidng of the situation.
I would hope so. Now the theory seems to be, well the earth was changing before, but now since man might be causing it, it is somehow much more dangerous. As if a 1 degree natural temperature increase is so much better than a man-made one. Scientifically, they offer no explaination for this assertion.
Somehow, they are saying this all happened before, but pay no attention to the man behind the curtain.
Yep, and their curtain is no different than OZ's, just a bunch of smoke and mirrors. Easily manipulated computer models pretending to be science.
Of course as we see our shipping ports destroyed the Europeans will become vegetarians and the South Americans will become carniovres and the Asians will . . .(starve) but God bless America things won't change all that much unless some other countries start launching intercontinental missiles in their pursuit of resoures.
IT WILL BE FUN!
Basically, the article says point blank that the "first" retreat had nothing to do with humans. I will make a fairly educated guess...that instead of talking of two episodes here...there might well have been over 100 episodes...and nothing can really be placed on the table to say that 100 percent of the problem is human-caused. We may yet have a relationship between the sun and earth...which might surprise a few educated folks. And that relationship, may not be a steady thing. Valleys and peaks may be part of a earth-sun relationship...and affect the glacer & ice shelves.
The end of the ice caused natural Global Warming or natural global warming caused an end of the ice age? Which is it prof?
I appreciate your deconstruction of my post rather than taking it as a whole. I guess there is a liberal somewhere in that body of yours.
Okay, first, it was my understanding that the ozone layer issue did not have anything to do with global warming, but with protection from UV rays. Second: Man made? Proof? It happened before naturally and there's no documentation that I know of showing that this cycle - repeat, CYCLE - is any worse or even any different. This is more fearmongering over a system that is so complex we can neither completely understand nor hope to control it.
2. If global warming is occurring, is that bad?
3. If global warming is occurring and it is bad, are humans causing it?
4. If global warming is occurring and it is bad and humans are causing it, can something be done now to reverse it?
5. If global warming is occurring and it is bad and humans are causing it and something can be done now to reverse it, are the costs of stopping global warming outweighed by the costs of doing nothing?
If you can provide factual support that demonstrates that each of those questions can honestly be answered in the affirmative, then I will support a campaign to stop human-caused global warming.
Coastlines have always changed, mostly due to errosion. Venice is safe for a long time. For as much as they spew about the oceans rising, despite over 100 years of mans assult on the global climate with greenhouse gases, oceans have yet to rise one inch. Oceans are at the same levels they were 150 years ago. They have just asserted this claim so many times, people assume it is true.
How, then, can he now FLATLY state that today's occurences are IN FACT man-made? How does he or any scientist worth their salt know without a doubt that the cycle is not now returning to a point on the wheel where the earth naturally gets warmer? Precession of the poles and earth orbit fluctuation?.......
Makes you wonder what happened 1000 years ago when the earth's average temperature was 6 degrees warmer than it is now.
If that's true, then how can they claim they are SURE this time, that the situation is caused by human activity?
I am going to steal this and use it elsewhere. I hope you think it is a compliment and are not offended.
If you are offended, then you are in the wrong place.
When will these enviroweenies get it? The earth is a living system, it adjusts as needed.. and is constantly changing. Millions of years ago microorganisms took CO2 and converted it to Oxygen... so much so, that they eventually made the air so oxygen rich that they all but died out.. yet had they not existed and done this, large animal life as we know it today based on oxygen couldn't exist....
Chop down trees in the rain forests, tree growth goes bonkers in europe... its a system, it changes and evolves and is hardly in any way shape or form on the verge of a complete collapse.
I never bought into the "ozone depletion by Freon" argument. Ozone layer is at the edge of the atmosphere and the Freon chloro-flourocarbon chemicals' molecules are heavier than air. How then does it get up there to destroy ozone? They have never really explained that to any satisfactory level........
Well, I would take this response as a whole, but it really makes little sense.
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