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.
I haven't either, to tell you the truth. The premise is that the UV rays' energy actually creates ozone by combining O2 and free oxygen into O3 (please, please keep me honest on this, folks). The CFCs suck up the free oxygen by combining with it, thereby robbing the outer layer of the atmosphere of the free oxygen needed to create the ozone and thereby suck the energy out of the UV rays.
Having said that, there is no connection between any supposed ozone layer effect and global warming. Two different issues.
I'd recommend Michael Crichton's "State of Fear".
If the earth was 6 degrees warmer 1000 years ago, shouldn't all of the antarctic ice have melted then? Is 1000 years long enough for it to refreeze? Was Manhattan Island completely under water?
If 6 degrees didn't melt the antarctic ice, why would anyone think a half degree of warming would melt it?
I think we're on the same page.
Is is just me, or is this statement 180degrees out of whack?
I heartily second that!
The envirowhacks are scrambling at this point. There is so much data contradicting their premises that they've switched from "Global Warming" to "Climate Change" as the big issue.
It is the land masses, islands, etc. that have risen or sunk that give some the view that the ocean level is going up/down. Just look at the before and after maps of the recent Asian Tsunami disaster.
You know its proof how stupid most people are that you and those who think like you are not in charge.
<-/sarcasim>
I love you homepage, comrade
You do know people who think like you killed 100 MILLION of their own people last century.
Now what was the theme for the first 'earth-day'?????....I remember! THE COMMING MAN MADE ICEAGE!
idiots.....
Ozone is regenerated constantly by the interaction of the solar winds, and the electromagnetic forces at the poles, as well as lightning strikes worldwide, and the Viking Kitties.
PERSPECTIVES: RISING CO2 LEVELS - THE REASON WHY ~~The earth has a cycle
"Retreat of Antarctic Ice Shelves Is Not New, Report Says"
I've heard of Italian ice but could it be that we have discovered "French ice"?
I note from reading Michael Crichton's new book, that global warming adherents often mention that the ice sheets are retreating in Antarctica. What they do not mention is that this is happening in only one relatively small area of Antarctica. Ice sheets in the rest of Antarctica, the vast majority of them are, in fact, advancing. So the question is: can we also blame the advancing ice sheets on mankind?
Those heavy chloro-flouro-carbon molecules get to our outer atmosphere the same way those heavy ozone molecules do...
"Social" promotion
LOL!
I knew it! That's the same thing my wife says.
This article is a grab bag of bad science and bad statistic driven by an agenda. for example:
The ozone layer blocks UV, and is purported to be diminished by chloroflourocarbons. There's no linkage of ozone "depletion" to global temperatures is there?
The average atmospheric CO2 level for the last 900K years may be 280 ppm, but there have been large, cyclical variations with the maxima puntuated by ice ages.
As long as we're talking personal beliefs, it's mine that the Earth is doing what it's always done. The evidence points toward a future iceage. If man has done anything to hasten or delay the onset of climate change it's more akin to a fart in a hurricane than to one in church.
Alaska will become a desert. It already would be a dusty desert except for the permafrost, and when the permafrost is gone the one foot a year of precipitation won't amount to much.
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