From the Potsdam Institute for Climate Impact Research (PIK) Alarmism, I think maybe they are a bit unclear on the concept of how glaciers work.
As snowfall varies with the seasons, the flow of ice speeds up and slows down.
Besides, it isn’t real data, but just another modeling scenario tweaked for a particular outcome. I had to laugh at this quote:
“We now know that snowfall in Antarctica will not save us from sea-level rise,”
More ice loss through snowfall on Antarctica
Stronger snowfall increases future ice discharge from Antarctica. Global warming leads to more precipitation as warmer air holds more moisture – hence earlier research suggested the Antarctic ice sheet might grow under climate change. Now a study published in Nature shows that a lot of the ice gain due to increased snowfall is countered by an acceleration of ice-flow to the ocean. Thus Antarctica’s contribution to global sea-level rise is probably greater than hitherto estimated, the team of authors from the Potsdam Institute for Climate Impact Research (PIK) concludes.
“Between 30 and 65 percent of the ice gain due to enhanced snowfall in Antarctica is countervailed by enhanced ice loss along the coastline,” says lead-author Ricarda Winkelmann. For the first time, an ensemble of ice-physics simulations shows that future ice discharge is increased up to three times because of additional precipitation in Antarctica under global warming. “The effect exceeds that of surface warming as well as that of basal ice-shelf melting,” Winkelmann says.
During the last decade, the Antarctic ice-sheet has lost volume at a rate comparable to that of Greenland. “The one certainty we have about Antarctica under global warming is that snowfall will increase,” Winkelmann explains. “Since surface melt might remain comparably small even under strong global warming, because Antarctica will still be a pretty chilly place, the big question is: How much more mass within the ice sheet will slowly but inexorably flow off Antarctica and contribute to sea-level rise, which is one of the major impacts of climate change.”
Since snowfall on the ice masses of Antarctica takes water out of the global water cycle, the continent’s net contribution to sea-level rise could be negative during the next 100 years – this is what a number of global and regional models suggest. The new findings indicate that this effect to a large extent is offset by changes in the ice-flow dynamics. Snow piling up on the ice is heavy and hence exerts pressure – the higher the ice the more pressure. Because additional snowfall elevates the grounded ice-sheet but less so the floating ice shelves, it flows more rapidly towards the coast of Antarctica where it eventually breaks off into icebergs and elevates sea level.
A number of processes are relevant for ice-loss in Antarctica, most notably to sub-shelf melting caused by warming of the surrounding ocean water. These phenomena explain the already observed contribution to sea-level rise.
“We now know that snowfall in Antarctica will not save us from sea-level rise,” says second author Anders Levermann, research domain co-chair at PIK and a lead author of the sea-level change chapter of the upcoming IPCC’s 5th assessment report. “Sea level is rising – that is a fact. Now we need to understand how quickly we have to adapt our coastal infrastructure; and that depends on how much CO2 we keep emitting into the atmosphere,” Levermann concludes.
Article: Winkelmann, R., Levermann, A., Martin, M.A., Frieler, K. (2012): Increased future ice discharge from Antarctica owing to higher snowfall. Nature [doi:10.1038/nature11616]
“Since snowfall on the ice masses of Antarctica takes water out of the global water cycle, the continent’s net contribution to sea-level rise could be negative during the next 100 years – this is what a number of global and regional models suggest. The new findings indicate that this effect to a large extent is offset by changes in the ice-flow dynamics.”
Models fighting models. I wonder if we can model the outcome of the discrepancy between the models…
On the subject of precipitation here’s news just in which could have some bearing on some global warming being blamed on some floods and intense rains.
The more you learn, the more you know
The more you know, the more you forget
The more you forget, the less you know
That must have been the first lesson they’ve learnt, but have already forgottent what it was about, so they reckon it’s related to snow, for a single letter should not matter much and that’s where the money comes from anyway. Is that clear?
I understand it, the more the entire planet warms (only the planet has not continued to warm since the cold war ended), and the more ice from Antarctica that melts as it evaporates into the atmosphere then the more it falls back as snow and ice on Antarctica. I understand that! Why is it, if it’s too cold for snow does Antarctica have all that frozen water? Maybe it was so warm Antarctica gained a lot of snow? or maybe the cold temperatures freeze H20. I see a catch 22 on the horizon.
Call me back when:
1. they have evidence of increased snowfall over a significant percentage of the Antarctic continent
and
2. they have RADARSAT evidence of increased stream velocities in the relevant Antarctic ice streams
Doug Proctor:
re your post at December 13, 2012 at 3:48 pm.
That is an excellent summary. I write to draw attention to it in hope that this will increase the number who gain from reading your post.
Richard
Well, call me when they do studies of previous sea levels much higher than we have today. Call me when they go to California to study the visible high stands. Call me when they realize sea level was much higher than today before the last glaciation began. It seems to me that some ‘scientists’ believe that sea level should be a static thing.
Even a warmist I saw on tv a few weeks ago after Sandy said sea level would not be rising as quickly as previously thought but even a millimeter a year or so alarmed him and he said we ‘have to prepare’. They simply cannot let go.
Syl says:
December 18, 2012 at 6:52 am
…..Even a warmist I saw on tv a few weeks ago after Sandy said sea level would not be rising as quickly as previously thought but even a millimeter a year or so alarmed him and he said we ‘have to prepare’. They simply cannot let go.
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
Boy is that evidence that they have ZERO math and science background. (A millimeter is about the same as three (female) fingernail thicknesses.) I am sure this guy thinks of a millimeter as about a foot or at least an inch (25.4 millimeters) or is hoping the audience is so ill-educated that THEY equate millimeters with meters or feet or at least inches .
Rivers are not in fact substantially fed by glaciers. So the whole disaster meme is a nullity.