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]
So… let me get this straight… as I read it, they’ve discovered:
“Ice does not infinitely build up in Antarctica” Who knew…
Then concluded that having X-30% or X-60% of new ice, constantly building up, causes the sea level to rise? What?
@mpainter:
Hmmm… good one… but doesn’t that also mean one could say:
“There has been no global warming this millennium!” ???
(Hey, if THEY can bend the truth, invent bogus stats, and generally make all out of proportion panic doomsaying out of nothing, then I can dress up a truth with some ‘seller puff’ 😉
BTW, if my post (above) seemed a bit off topic, my point was that these same people keep pumping out these same reports, based on the same weak science or no science. They KNOW their models are faulty. They’ve known that for years. And, while they are in it for the money, they must KNOW that roll-on effect is catastrophic for civilization and all of humankind. They KNOW what they are doing. When are they going to face up to themselves?
“Between 30 and 65 percent of the ice gain due to enhanced snowfall in Antarctica is countervailed by enhanced ice loss along the coastline,” Unless basic percentage maths has changed since I was at secondary school (college) 50 years ago, then it follows that 35-70% of the enhanced snow-fall accretes and adds to ice gain, taking water out of the oceans. Anyway you look at it, it’s a net gain for the frozen waste. Don’t they teach logic or maths at warmist school any more?
What if (ha) my pen was blue, and I use my blue pen everyday. what if (ha) tomorrow I changed the type of pen I used. What color would my blue pen be?
Answers on a self addressed envelope please.
Some of those glaciers must be awfully long if they all “reach the sea” as this paper seems to claim.
Louis:
There isn’t any logic.
That is the main problem.
As Don Easterbrook says: “The authors apparently didn’t bother to check the temperature records at the South Pole and Vostok, which go back to 1957 and show no warming whatsoever over the past 55 years.” Surely this must worry both the editors of Nature and those funding the work. All they have to ask is for the authors to produce the empirical data supporting their claims about Antarctic temperature history. What the hell is happening to science these days?
Remarkable. More snow and ice = higher sea levels. Higher sea levels = even more snow and ice. A perfect feedback loop, creating H2O (as snow and ice) out of nothing. Who’d have thought it? (sarc off).
Bull 541t.
More on antarctic ice, this time from the British Antarctic Survey. It appears they’re all at it together.
H/T NoTricksZone
http://notrickszone.com/2012/11/12/study-confirms-antarctic-sea-ice-expanding-due-to-climate-change-british-antarctic-survey-scientists-claim/
The more snow that falls on Antarctica the heavier the glaciers become, and eny fule kno that heavy bodies fall faster than light bodies.
Actually it’s not because of CO2. The real warming started when Daylight Saving Time was instituted. All that extra Daylight gets turned into heat and that has to go somewhere. The really scary part is that extra hour 7 months of the year is actually depleting the sun’s energy about 2.4% faster! This means the sun will run out of energy a lot sooner than we planned, and then we will really have a problem to deal with!
/sarc just in case one of the alarmists is reading this
Are their hindcasts compatible with earth orientation parameter & oblateness records?
(These are rigid constraints. My guess is they ignore inconvenient observed aggregate constraints. Nobody wants to get caught suggesting violations of the laws of large numbers and conservation of angular momentum.) This press release smells particularly foul & corrupt. In order for mainstream institutions to maintain the trust of sensible members of the public, this work should be audited by capable parties with lucid awareness of aggregate constraints. (Paywalls also don’t help with maintaining public trust.)
We better hope the volume of ice on Antarctica doesn’t grow appreciably. As we know, the earth wobbles on its axis. Due to centrifugal force, the more weight accumulated off-axis will logically increase the wobble. In time, this will cause the earth to explode and the pieces go flying off in all directions. That could spoil your whole day.
/sarc off
They’ve discovered a maximum amount of ice that can be supported by a continent after which it slides off? And with that scientific discovery, they can predict that at some point in the fuiture that almost all of the ice will fall of Antarctica due to unstoppable global warming and those of us not already fried will drown. Doesn’t sound all that scientific and full of crevices.
Has it already sank in that Greenlandic mass-loss has increased five-fold in 20-years, and that Antactic mass-balance is also somewhat negative (Shepherd et. al. 2012):
http://imbie.org/imbie-2012/results/
ps. Greenland has warmed up a lot in the last 20 years, both from above and via the sea.
“MostlyHarmless says:
December 13, 2012 at 12:32 am
Some of those glaciers must be awfully long if they all “reach the sea” as this paper seems to claim.”
Yes, on Antarctica the longest ice-streams are 1000+ km long, see nice animation over here:
http://www.ess.uci.edu/videos/rignotanim
A.D Everard, NO you are not off topic, there is little evidence of science, the scientific method or rational thinking about the planet and its weather systems.
All of the above seem to be cover, a cloak for a humourless self hating bunch. Persons so afraid, that they must control everything and everyone.
The CRU emails woke me up, the unease I was developing about the UN-IPCC and CAGW as I observed the battles for data exposed at Climate Audit& WUWT.
Also from my personal inability to access empirical science that supported the UN’s conjecture.
I would have called you a conspiracy nut, if you had told me what was in the contrast between the IPCC-FAR, the endless press statements from the team and the CRU emails.
Since late 2009 I have been in the grip of a growing anger, the alarm sounding crew are devious and foolish. After near 30 years of “The sky is falling because of our sin of civilized living”, all the deliberate falsehoods and attacks on our society these UN clowns and enablers probably believe they can just fade away and keep their ill-gotten gains and or pensions.
Guess we will see.
Why then did the last major glaciation melt from SE Wisconsin back to above the arctic circle? Must of been a lot of global warming going on 10-12 thousand years ago.
For what it is worth, a map of Antarctica without ice and the flows of ice labeled in meters per year, Source University of California
http://sciencedude.blog.ocregister.com/files/2011/08/GlacierAntartica.jpg
Volcanoes in Antarctica map
http://icecap.us/images/uploads/AntarcticVolcanoes2.jpg
And the WUWT article: http://wattsupwiththat.com/2008/01/22/surprise-theres-an-active-volcano-under-antarctic-ice/
grumpyoldmanuk completely nailed it. The press release is at war with itself.
If only 30-65 % of the mass gain from increased snowfall is balanced by increased loss, that
means the ice gains mass. Period.
I read this a couple of times and can’t understand it. Based on the article It seems that if it stopped snowing in Antarctica the glaciers would grow ever and ever bigger? or am i meant to conclude that whatever happens the glaciers are all going to rush into the sea and we’ll all drown
“Between 30 and 65 percent of the ice gain due to enhanced snowfall in Antarctica is countervailed by enhanced ice loss along the coastline”
As Penny on Big Bang Theory would say, “Holy crap on a cracker!”
I was a glaciology student. Okay, I have an edge. A very little edge. As Anthony says, the author of the above comment (at least) fails on the concept. Since the snowfall comes from the ocean (the first principle), 35 – 70% of the increased, held (short-term) snowfall means a LOWERING of sea-level.
The second principle of glaciology that appears lost on all climate warmists is that glaciers move because the accumulated weight (force) of ice causes the solid (ice) to become plastic and flow. All glaciers, ice masses that move, are by definition unstable: they will continue to “thin-out” until the weight (causing flowage) is equal to the resistive pressures of friction and crystalline rigidity. Glacial movement does not indicate climate change, warming weather at all, but the current result of an earlier, historical period in which the rate of mass additions exceeded the rate of melting, sublimation and plastic flow.
There is still a third principle of glaciology that is lost on climate warmists: that all glacial mass reductions are attributable to three processes:
1) plastic flowage that terminates in the ocean or large lakes (so that calving occurs and movement to warmer climes),
2) sublimation, and
3) melting.
All glacial mass increases are due to one process: snowfall.
Greenland and Antarctica lose glacial mass year-to-year ONLY IF the rate of loss is greater than the rate of gain. Of the three methods of ice mass, only two are in any way related to warming. Melting is an obvious result of warming, but as most of the continental ice volumes are in areas which are below zero for most of the year, you can easily determine the change of amount of ice potentially melted, IF YOU CONCLUDE that thermal conductivity of ice is low. Ratio delta ice melt = delta temp increase X ratio delta time above melting X 1/heat of solid-liquid state change.
I say, IF YOU CONCLUDE, because the second method of ice loss, increased plastic flowage to the sea, claimed by warmists to be significant, assumes a high thermal conductivity to ice. Only if the general ice mass has warmed can increases in flowrate be attributed to warming, but this consideration reduces the potential for melting (as heat is conducted into the lower zones rather than used to effect a state change). So plastic flowage and melting are opposing considerations, in that you cannot pump for one while pumping for the other. There is only so much energy around.
Sublimation, while impacted by warming, is only marginally impacted by warming when you are hovering around zero. Sublimation is only a real force when sunshine is strong under dry atmospheric conditions. The more you make water vapour rise, the less sublimation occurs, especially if you think more water vapour leads to more clouds (which reduces sunshine getting to the glacier).
With all the above considerations, what really causes loss of glacial mass is the non-deposition of replacement snow. Since the existing glacial flow is a function not of recent ice gain, but of historical gain, you must be very careful in attributing glacial net ice loss to current conditions: you first must determine that current snowfall is not significantly less than historical amounts.
I do not believe this has been determined. If winter precipitation has dropped below historical levels, then you have, like Kilamanjaro, a problem not of warming, but of precipitation sourcing.
So far I have heard absolutely zero increase in iceberg activity. The large shelves don’t count. They break off all the time, and do not contribute to sea-levels. We need to see icebergs increasing. And we still need to talk about replacement snow.
“Glacier speed can vary from virtually at rest to a kilometer or more per year. On average, though, glaciers move at the laggardly pace of a couple hundred feet per year. In general, a heavier glacier moves quicker than a lighter one, a steep glacier quicker than a less steep one, a warmer glacier quicker than a cooler one.”
So, just how much glacier ice (deposited in the last 30 years of supposed global warming) is getting MOVED into the oceans around Antarctica? Sea ice – and Antarctic sea ice is newly frozen every year, meled every summer – avcerages 1-1.5 meters thick. So one square km of sea ice = 1000 meters x 1000 meters x 1 meter thick. 10^6 cubic meters of ice. A glacier is (perhaps, or at most) 30 meters thick when it calves off and falls in the ocean. (Glaciers – at their tips – are NOT 1 meter thick. Few are 10 meters thick.) Glaciers are the width of their spawning valley (maybe 1 km wide at the most) it is the massive ice caps that are 100 to 1000 km wide. And THOSE do not “flow” to the sea. They are static,rarely breaking off; and when they do break off, they don’t break apart and spread out. they stay in massive thick island of ice. Those “islands” of ice DON’T spread out and increase sea ice extents!
Seems to me that – at MOST – about a 30 km “length” of glacier valley “ice” could be moved to the coast, and almost all of that was ice that was created hundreds (thousands) of years ago and is getting “moved” by ice + compressed snow getting deposited on top of the old ice.
Now, if today’s sea ice is 1,000,000 square to 1,500,000 square kilometers LARGER than any previous records for antarctic sea ice, then – if as these “scientist” apparently want us to believe – that new sea ice is coming (largely ?) from glacier snow newly deposited on top of old glacier ice that is moving less than 1 km per year towards the ocean edge …..
Where is the “new” sea ice coming from ?
The numbers PROVE it is NOT able to come from the glaciers previously attached to the rocks and contient of Antarctica.
I guess these guys don’t understand the concept of a “push”.
How smart do you have to be to assert that an increased ice flow that’s caused by a thicker, deeper, land-based ice sheet will raise sea levels? Seriously, I want to know how someone can make such an assertion.
My theory: years of public education grade inflation and University pH.D peddling are coming home to roost.