.NASA data: Greenland, Antarctic ice melt worsening
WASHINGTON (AP) - New satellite information shows that ice sheets in Greenland and western Antarctica continue to shrink faster than scientists thought and in some places are already in runaway melt mode.
British scientists for the first time calculated changes in the height of the vulnerable but massive ice sheets and found them especially worse at their edges. That's where warmer water eats away from below. In some parts of Antarctica, ice sheets have been losing 30 feet a year in thickness since 2003, according to a paper published online Thursday in the journal Nature.
Some of those areas are about a mile thick, so they've still got plenty of ice to burn through. But the drop in thickness is speeding up. In parts of Antarctica, the yearly rate of thinning from 2003 to 2007 is 50 percent higher than it was from 1995 to 2003.
These new measurements, based on 50 million laser readings from a NASA satellite, confirm what some of the more pessimistic scientists thought: The melting along the crucial edges of the two major ice sheets is accelerating and is in a self-feeding loop. The more the ice melts, the more water surrounds and eats away at the remaining ice.
"To some extent it's a runaway effect. The question is how far will it run?" said the study's lead author, Hamish Pritchard of the British Antarctic Survey. "It's more widespread than we previously thought."
The study doesn't answer the crucial question of how much this worsening melt will add to projections of sea level rise from man-made global warming. Some scientists have previously estimated that steady melting of the two ice sheets will add about 3 feet, maybe more, to sea levels by the end of the century. But the ice sheets are so big it would probably take hundreds of years for them to completely disappear.
As scientists watch ice shelves retreat or just plain collapse, some thought the problem could slow or be temporary. The latest measurements eliminate "the most optimistic view," said Penn State University professor Richard Alley, who wasn't part of the study.
The research found that 81 of the 111 Greenland glaciers surveyed are thinning at an accelerating, self-feeding pace.
The key problem is not heat in the air, but the water near the ice sheets, Pritchard said. The water is not just warmer but its circulation is also adding to the melt.
"It is alarming," said Jason Box of Ohio State University, who also wasn't part of the study.
Worsening data, including this report, keep proving "that we're underestimating" how sensitive the ice sheets are to changes, he said.
MyWay
British scientists for the first time calculated changes in the height of the vulnerable but massive ice sheets and found them especially worse at their edges. That's where warmer water eats away from below. In some parts of Antarctica, ice sheets have been losing 30 feet a year in thickness since 2003, according to a paper published online Thursday in the journal Nature.
Some of those areas are about a mile thick, so they've still got plenty of ice to burn through. But the drop in thickness is speeding up. In parts of Antarctica, the yearly rate of thinning from 2003 to 2007 is 50 percent higher than it was from 1995 to 2003.
These new measurements, based on 50 million laser readings from a NASA satellite, confirm what some of the more pessimistic scientists thought: The melting along the crucial edges of the two major ice sheets is accelerating and is in a self-feeding loop. The more the ice melts, the more water surrounds and eats away at the remaining ice.
"To some extent it's a runaway effect. The question is how far will it run?" said the study's lead author, Hamish Pritchard of the British Antarctic Survey. "It's more widespread than we previously thought."
The study doesn't answer the crucial question of how much this worsening melt will add to projections of sea level rise from man-made global warming. Some scientists have previously estimated that steady melting of the two ice sheets will add about 3 feet, maybe more, to sea levels by the end of the century. But the ice sheets are so big it would probably take hundreds of years for them to completely disappear.
As scientists watch ice shelves retreat or just plain collapse, some thought the problem could slow or be temporary. The latest measurements eliminate "the most optimistic view," said Penn State University professor Richard Alley, who wasn't part of the study.
The research found that 81 of the 111 Greenland glaciers surveyed are thinning at an accelerating, self-feeding pace.
The key problem is not heat in the air, but the water near the ice sheets, Pritchard said. The water is not just warmer but its circulation is also adding to the melt.
"It is alarming," said Jason Box of Ohio State University, who also wasn't part of the study.
Worsening data, including this report, keep proving "that we're underestimating" how sensitive the ice sheets are to changes, he said.
MyWay
posted by madtom at 9:00 PM
5 Comments:
http://www.ocregister.com/ocregister/opinion/columns/article_1245606.php
I won't get into a duel, but the ocean temps are cooling, not warming. Why is the artic going through a melting stage as is Greenland? I dunno and neither do this eggheads whose livliehoods and reputations are based on their convincing us poor dumb fucks that only they can save us. I read and alarming article the other day that some ancient human settlements had been revealed by the retreating ice--- that told me something entirely different that the intended warning, like this is normal. You do know that the Antarctic ice is growing? Why? I'm sure the eggheads have a reason and only they can explain it, but they need more money to get a firm answer--- and even more money to stop it, or speed up the growth, or whatever fits your fear--- they can fix it, but it's gonna cost you money and more importantly, your freedom.
"Antarctic ice is growing?"
But Will, that would be cause for alarm. The Antarctic is one of the driest deserts on the planet.
Of course it's cause for alarm. If the ice were shrinking, that would be cause for alarm. If it was steady, that would be cause for alarm. Let's all be alarmed together.
Well when you get sudden changes in the weather patterns of a place like Antarctica people take notice.
And of course if its raining in one of the driest places in the world, really you guys should stop repeating that little nugget of information. If I were you I would hide that fact, not touted it like proof.
http://www.theregister.co.uk/2009/09/29/yamal_scandal/
More cherry picking in the data that is the Gospel of Global Warming and the cover up of the facts.
''From this we know that the Yamal data set uses just 12 trees from a larger set to produce its dramatic recent trend. Yet many more were cored, and a larger data set (of 34) from the vicinity shows no dramatic recent warming, and warmer temperatures in the middle ages.''
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