Posted on 09/28/2005 6:27:13 PM PDT by blam
Arctic ice cap 'will disappear within the century'
By Roger Highfield, Science Editor
(Filed: 29/09/2005)
The Arctic ice cap is on track to disappear within a century, according to a study published yesterday.
The satellite survey by the US National Snow and Ice Data Centre (NSIDC), and the space agency Nasa reveals that for the fourth consecutive year there has been "a stunning reduction" in Arctic sea ice at the end of the northern summer, placing species such as polar bears at risk.
The reduction in ice levels places Arctic wildlife at risk
The survey recorded the lowest sea-ice extent yet seen - 2.06 million square miles on Sept 19 - 20 per cent below the mean average September sea-ice extent from 1978 to 2001.
That is the equivalent of 500,000 square miles - an area about twice the size of Texas.
This year "will almost certainly surpass 2002 as the lowest amount of ice cover in more than a century", said Julienne Stroeve, of the Centre. If current rates of decline in sea ice continue, the summertime Arctic could be ice-free well before the end of this century.
A recent assessment of trends throughout the past century indicates that the current decline also exceeds past low ice periods in the 1930s and 1940s.
From 1979 until 2001, the rate of September decline was slightly more than 6.5 per cent a decade. In 2002, the trend steepened to 7.3 per cent and is now approximately 8 per cent.
Walt Meier, of NSIDC, said: "Having four years in a row with such low ice extents has never been seen before in the satellite record. It indicates a downward trend, not just a short-term anomaly."
Cooler winter temperatures allow the sea ice to "rebound" after summer melting. But with the exception of May 2005, every month since December 2004 has set a new record low ice extent for that month. The winter recovery of sea ice extent in the 2004-05 season was also the smallest observed by satellites.
"Even if sea ice retreated a lot one summer, it would make a comeback the following winter, when temperatures fall well below freezing," said Florence Fetterer, of NSIDC. "But in the winter of 2004-05, sea ice didn't approach the previous wintertime level."
Compared to the past half century, average surface air temperatures from January until August 2005, were up to 3C (5.4F) warmer than average across most of the Arctic Ocean. Since 2002, satellite records have also revealed that springtime melting is beginning unusually early north of Alaska and Siberia.
This summer, the Northwest Passage was open except for a 60-mile swath of scattered ice floes, a far cry from earlier centuries when expeditions were lost as their crews tried to beat through thick ice. The Northeast Passage, north of the Siberian coast, was ice-free from Aug 15 until Sept 28.
The Arctic may be caught in a feedback loop caused by global warming. As sea ice melts there is less to reflect the sun's radiation back into space and experts fear that the downward trend is reaching a point from which the ice will not recover.
Yeah we usually see the first of our global warming about the end of October but it doesn't usually stick until the end or November.
Nailed it. Just nailed it. Well done.
I heard on the news last night that the interior got some global warming yesterday.
I have to insulate and heat tape, my new pitless well connection, and my new certified septic, before we start getting global warming down here in the northern Susitna.
We get lots of birds here. But they spread out in the summer. In winter I have to stand in the dog yard after I feed them or the Ravens will get more food than the mutts.
The most Ravens we've ever had here was almost thirty! The Magpies and Grey Jays run clean up.
See? This is the second magpie I have seen here. All this summer. This is PROOF of global warming. That, plus there is enough global warming from the front stoop to see on my global warming shovel.
Not if they are talking about ice that is floating. You see, if it is floating on the water, then it has already displaced all the water it is ever going to.
Ice on land, yes, but take a good look at a satelite image of the earth, and compare the amount of ice on land with the surface area of the oceans. To me, it looks like only a few percentage points, at most. And if all of it melted in our lifetime, how much higher could that amount of icemelt possibly raise the level of the water?
Sorry to burst your bubble.
:-)
So what will happpen to Santa Claus???
I guess he'll just have to get a job in Congress, or better yet, the U.N.
Now that sounds like an investment opportunity! Buy a mountain, build a ski resort.
Money lenders; please FReepmail me with your best offer.
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