From NASA JPL and Lamont-Doherty Earth Observatory, something that maybe journo-hacktivist Susanne Goldenberg should pay attention to before she writes another screed.
Reports that a portion of the West Antarctic Ice Sheet has begun to irretrievably collapse, threatening a 4-foot rise in sea levels over the next couple of centuries, surged through the news media last week. But many are asking if even this dramatic news will alter the policy conversation over what to do about climate change.
Glaciers like the ones that were the focus of two new studies move at, well, a glacial pace. Researchers are used to contemplating changes that happen over many thousands of years.
This time, however, we’re talking hundreds of years, perhaps — something that can be understood in comparison to recent history, a timescale of several human generations. In that time, the papers’ authors suggest, melting ice could raise sea levels enough to inundate or at least threaten the shorelines where tens of millions of people live.
“The high-resolution records that we’re getting and the high-resolution models we’re able to make now are sort of moving the questions a little bit closer into human, understandable time frames,” said Kirsty Tinto, a researcher from Lamont-Doherty Earth Observatory who has spent a decade studying the Antarctic.
“We’re still not saying things are going to happen this year or next year. But it’s easier to grasp [a couple of hundred years] than the time scales we’re used to looking at.”
The authors of two papers published last week looked at a set of glaciers that slide down into the Amundsen Sea from a huge ice sheet in West Antarctica, which researchers for years have suspected may be nearing an “unstable” state that would lead to its collapse. The West Antarctic Ice Sheet is mostly grounded on land that is below sea level (the much larger ice sheet covering East Antarctica sits mostly on land above sea level).
Advances in radar and other scanning technologies have allowed researchers to build a detailed picture of the topography underlying these glaciers, and to better understand the dynamics of how the ice behaves. Where the forward, bottom edge of the ice meets the land is called the grounding line. Friction between the ice and the land holds back the glacier, slowing its progress to the ocean. Beyond that line, however, the ice floats on the sea surface, where it is exposed to warmer ocean water that melts and thins these shelves of ice. As the ice shelves thin and lose mass, they have less ability to hold back the glacier.
What researchers are finding now is that some of these enormous glaciers have become unhinged from the land – ice has melted back from earlier grounding lines and into deeper basins, losing its anchor on the bottom, exposing more ice to the warmer ocean water and accelerating the melting.
In their paper published in Geophysical Research Letters, Eric Rignot and colleagues from the University of California, Irvine, and NASA’s Jet Propulsion Laboratory in Pasadena, Calif., described the “rapid retreat” of several major glaciers over the past two decades, including the Pine Island, Thwaites, Haynes, Smith and Kohler glaciers.
“We find no major bed obstacle upstream of the 2011 grounding lines that would prevent further retreat of the grounding lines farther south,” they write. “We conclude that this sector of West Antarctica is undergoing a marine ice sheet instability that will significantly contribute to sea level rise in decades to come.”
The region studied holds enough ice to raise sea levels by about 4 feet (Pine Island Glacier alone covers about 62,000 square miles, larger than Florida). If the whole West Antarctic Ice Sheet were to melt, it could raise the oceans about 16 feet.
In the second paper, Ian Joughlin and colleagues from the University of Washington used models to investigate whether the Thwaites and Haynes glaciers, which together are a major contributor to sea level change, were indeed on their way to collapsing. “The simulations indicate that early-stage collapse has begun,” they said. How long that would take varies with different simulations – from 200 to 900 years.
“All of our simulations show it will retreat at less than a millimeter of sea level rise per year for a couple of hundred years, and then, boom, it just starts to really go,” Joughin said in a news release from the University of Washington.
Many scientists who’ve been studying the region were already braced for the storm.
“It’s gone over the tipping point, and there’s no coming back,” said Jim Cochran, another Lamont researcher with experience in the Antarctic. “This … confirms what we’ve been thinking for quite a while.”
Cochran is principal lead investigator for Columbia University in Ice Bridge, the NASA-directed program that sends scientists to Antarctica and Greenland to study ice sheets, ice shelves and sea ice using airborne surveys. Much of the data used in the new papers came from the Ice Bridge project.
Tinto, also an Ice Bridge veteran, agreed. “I thought it was pretty exciting, because we’ve all been working on this area for a long time, and that potential for the West Antarctic Ice Sheet to behave in this way, we’ve been aware of it for a long time,” she said. “[It] made me want to get in there and look at the rest of the area, what else is going on.”
And there are still many questions about what’s going on: How fast the ocean that swirls around Antarctica is warming, how those ocean currents shift, and to what extent that is influenced by global warming.
“I have a problem with the widespread implication (in the popular press) that the West Antarctic collapse can be attributed to anthropogenic climate change,” said Mike Wolovik, a graduate researcher at Lamont-Doherty who studies ice sheet dynamics. “The marine ice sheet instability is an inherent part of ice sheet dynamics that doesn’t require any human forcing to operate. When the papers say that collapse is underway, and likely to last for several hundred years, that’s a reasonable and plausible conclusion.”
But, he said, the link between CO2 levels and the loss of ice in West Antarctica “is pretty tenuous.”
The upwelling of warmer waters that melt the ice has been tied to stronger westerly winds around Antarctica, which have been linked to a stronger air pressure difference between the polar latitudes and the mid-latitudes, which have in turn been linked to global warming.
“I’m not an atmospheric scientist, so I can’t evaluate the strength of all of those linkages,” Wolovik said. “However, it’s a lot of linkages.” And that leaves a lot of room for uncertainty about what’s actually causing the collapse of the glaciers, he said.
Researchers have been discussing the theory of how marine ice sheets become unstable for many years, said Stan Jacobs, an oceanographer at Lamont-Doherty who has studied ocean currents and their impact on ice shelves for several decades.
“Some of us are a bit wary of indications that substantial new ground has been broken” by the two new papers, Jacobs said. While ocean temperatures seem to be the main cause of the West Antarctic ice retreat, there’s a lot of variability in how heat is transported around the ocean in the region, and it’s unclear what’s driving that, he said. And, he’s skeptical that modeling the system at this point can accurately predict the timing of the ice’s retreat.
But, he added, “this is one more message indicating that a substantial sea level rise from continued melting of the West Antarctic Ice Sheet could occur in the foreseeable future. In the absence of serious near-term greenhouse gas mitigation efforts, such as an escalating tax on carbon, they may well be right.”
“It starts bringing it a little closer to home,” said Tinto. “It’s a significant amount of change, but something we can start planning for. Hopefully [this will] make people stop procrastinating and start planning for it.”
Cochran agreed: The papers’ message is “that … over the next couple hundred years, there’s going to be a significant rise in sea level, and at this point we can’t stop it.” But, he added, “it doesn’t say give up on trying to cut emissions. … [Just] don’t buy land in Florida.”
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Source: http://blogs.ei.columbia.edu/2014/05/23/clock-is-ticking-in-west-antarctic/
h/t to Marc Morano of Climate Depot
The two papers in question:
Widespread, rapid grounding line retreat of Pine Island, Thwaites, Smith and Kohler glaciers, West Antarctica from 1992 to 2011, E. Rignot, J. Mouginot, M. Morlighem, H. Seroussi, B. Scheuchl, Geophysical Research Letters (2014)
Marine Ice Sheet Collapse Potentially Underway for the Thwaites Glacier Basin, West Antarctica, Ian Joughin, Benjamin E. Smith, Brooke Medley, Science (2014)
During the last interglacial (Eemian) about 100,000 years ago, sea level was at least 3 meters (10 feet) higher than now. Sea level was about 20 meters (65 feet) higher during MIS11 a particularly long interglacial (50,000 years) about 400,000 years ago.
What this suggests is that the amount of glacier melting depends on the length of the time as well as the temperature.
Something everyone knows who has ever put ice cubes in drinks.
They are fairly loose with their use of English, using terms like “slow” and “fast” without giving any numbers. However my favorite usage is, “Runaway Glaciers.”
Next time my wife asks me to do something, I’ll tell her I’ll be onto the task “with the speed of a runaway glacier.” That will reassure her, for that is a lot faster than my usual glacial pace.
Surely these guys flunked English classes. Not only do they use a word usually used to denote slowness to alarm us with speed, but they misuse the word “runaway.” The word implies uncertainty, but they suggest they are certain. The word implies lack of control, but who controls a glacier? The word suggests someone fleeing rules, responsibilities, and consequences, which are things inanimate objects like glaciers don’t care a hoot about.
“Hey you! Mr. Glacier! Get back here!”
“No! I’m running away!”
Mr. Glacier is a lot faster than you would think a glacier could be. He is so fast he is retreating from the grounding line….ummm…err…how fast is that?
It is so fast Mr. Glacier is losing weight, and is a “thinning” glacier. Nothing worse than a fat glacier, you know. And obesity is a real problem, these days. Mr. Glacier is setting a good example, for, by moving more mass more quickly he winds up with less…umm…errr…
Either that, or maybe Mr. Glacier moves with glacial speed, and is so slow to respond that what we are seeing is a response to warming that ended twenty years ago.
Quote:
The level shore platform has been eroded by wave
action across the rocky coastline during the past
7000 years. The big fold was formed during the
mountain building about 500 million years ago.
During the Recent ice age about 20 000 years ago,
sea level was about 130 metres lower than today
and South Australia’s coastline was about 150
kilometres south of where Victor Harbor now is.
The ice cap started to melt about 15 000 years ago.
Sea level began to rise and reached its present level
about 6000–7000 years ago.
Yes folks before that 130M sea level rise, the aboriginal folk could walk on land from Adelaide to Edithburgh across what is now Gulf St Vincent and south of Kangaroo Island but their descendants today will need to catch the diesel ferry there. Damned inconsiderate of those past aboriginal folk with their cooking fires and bush burnoffs to flush out game, although much of Australia’s flora needs bushfire to regenerate today as a result.
http://www.sa.gsa.org.au/Brochures/HallettCoveBrochure.pdf
Not hard to see why geology buffs like Ian Plimer think we should be concentrating on the rocks in the ground instead of the rocks in Big Climate heads.
And since Big Climate do like their averages and decimal points, 130,000 mm divided by 7000 years equals 18.571428mm per year give or take a decimal point or two so relax guys. OTOH we’ve got a wee bit of catching up to do if sea levels can rise 130 metres in a 1000 years wouldn’t you say chaps?
But the best bit for Big Climate idiots is the light bulb moment in 1875 less than 40 years after whitefellas like Edward Gibbon Wakefield rolled up from merry old England to set up a model free Utopia is this-
Hallett Cove is one of the best known geological sites
in Australia, because of the evidence of an ancient
glaciation discovered in 1875 by Professor Ralph Tate
from the University of Adelaide. The polished and
striated glacial pavements, and sediments associated
with the glaciation, are now known throughout the
world.
The area has been declared a Geological Monument
by the Geological Society of Australia and placed on
both the South Australian Heritage Register and the
former Register of the National Estate because of its
significance for educational and scientific purposes.
Don’t forget to look it up if yer down our way anytime, treemometer and coremometer people.
It’s quite amazing to witness how these people (are they actually ‘glaciologists’ one wonders, do they actually know how glaciers work?) continue to spew their nonsense. Ground stations in the West Antarctic and especially in the Peninsula do not show warming over the last three decades. The satellites don’t either. The sea surface temperatures in the regions haven’t warmed over that same period. Any warming stopped 30-40 years ago. And OHC, well who’s to know? We basically haven’t got any measurements at all prior to the ARGO era, that’s the last ten years …!
This is all about glacier dynamics. Cycles in a glacier’s life. Don’t these people know about glaciers’ RESPONSE TIME to a change in local climate? Don’t these people know how gigantic the glaciers in question are? Like another commenter on this thread pointed out, do people seriously think that after 50 years (or rather 25-30, from 1976 to 2001) of alleged ‘anthropogenic global warming’, warming that hasn’t even been observed in the Antarctic region, in the western part only up until the earliest part of the 80s, that the huge glaciers down there now all of a sudden starts collapsing as a result of ‘this’? How ridiculously unscientific can you get?
Don’t these people know about the TIDEWATER GLACIER CYCLE?
http://en.wikipedia.org/wiki/Tidewater_glacier_cycle
“The size of tidewater glaciers is such that the tidewater glacier cycle is several hundred years in length. A tidewater glacier is not sensitive to climate during the advancing and drastically retreating phases of its cycle.”
“What researchers are finding now is that some of these enormous glaciers have become unhinged from the land – ice has melted back from earlier grounding lines and into deeper basins, losing its anchor on the bottom, exposing more ice to the warmer ocean water and accelerating the melting.” – If the ice is floating surely any impact it has on sea levels has already happened?
1. Make model
2. Input data
3. Run hundreds of years into the future
4. BOOM[Joughin said], it explodes.
As Gomer Pyle would say: ‘Surprise Surprise Surprise!” Not.
Probably a consequence of their assumptions. I think they need to watch “Boom goes the dynamite.”
As my economics professor used to say, “Constants seldom are, and variables always do.”…
The 0.75C of global warming experienced since the Little Ice Age ended in 1850, has obviously contributed to global glacier loss, but who cares?
During the Little Ice Age (1280~1850), global glacial ice increased rapidly, and many villages in glacier valleys were destroyed by advancing ice; scary stuff, but you can’t fight Mother Nature.
For example, during the end of the Wolf Grand Solar Minimum (1280-1350), European winters were so severe, that roughly 25% the European population froze to death or died of famines caused by a string of awful crop seasons, brought about by very late springs, very early autumn frosts and insufficient sunlight and rainfall; it was a dark and dreary time..
This was followed by the Black Death coupe de grace (1346~1352), which managed to wipeout 50% of the remaining European population that had not died of exposure or famine over the previous few decades….
Just as now, the ruling elites of the time exploited these natural tragedies to persuade their citizens to change their evil ways (and pay the piper) or suffer the dire consequences of their lifestyles; a kind of fire (and brimstone) insurance policy, if you will.
“Never let a crisis go to waste”~ Rohm Emmanuel, Chief of Staff (the Obama Administration)
Isn’t funny how history repeats itself?
The Little Ice Age continued on for another 500 years, but when man started harnessing the power of fossil fuels and building machines to replace animal and human power, the human condition and living standards rose exponentially.
I guess the fire (and brimstone) insurance policies finally paid off…just 400 years too late…. Oh, wait a minute.. that’s post hoc, ergo proctor hoc.
But wait, the Industrial Revolution started at about the same time as the Little Ice Age ended, so it must have been the Industrial Revolution that caused the Little Ice Age to end… Oh, wait, that’s post hoc, ergo proctor hoc, too… Darn.
Never mind.
‘Advances in radar and other scanning technologies have allowed researchers to build a detailed picture of the topography underlying these glaciers, and to better understand the dynamics of how the ice behaves.’
So in reality they do not have historic data from which they can ‘know’ that in the past the situation was very different , they can speculate it was and from there guess what the future will hold .
In reality the Antarctic’s failure to melt , even worse its getting bigger , has been a real head ache for those pushing ‘the cause’ and this speculation give them a ‘solution’ by which even has it grows they can claim where doomed anyway unless we take action now . Tails you lose , heads I win , PP science but normal for climate ‘science’.
Can someone explain how climate responds to carbon taxes? How does the transferring of funds from.one group of people to another lower temperature or stabilize ice sheets?
Well, if the sea water is warm enough to melt ice and the wind blows inland then we should get more snow – meaning the snow/ice pack in central Antarctica is getting bigger!
That should offset the sea water rise by the melting doesn’t it?
Why are the glaciers melting inland? Maybe vulcanic activity? This is detected on the West-peninsular!
Are there any seismic activities? The reason I ask is that all other land masses move North, only Antarctica is stagnant at the moment…
I am so tired of the “tipping point” BS! Prove one tipping point in historical climate data and I will give the term some respect. The scare tactic of the alarmists implying that ” now nothing can be done”. I assume they are including natural processes and variations, known and unknown, and wonder how this can be considered fact with out testing using some kind of control.
It is a meaningless term when used in a chaotic system such as climate. Another political term being forced into science by those who prostitute their names and positions to politics for money. I doubt I can use the W**** word, but I am sure you get my meaning
During at least the last four interglacial periods sea level has been several meters higher and temperatures several degrees warmer (at their climate optimums), so everything they’ve concluded MIGHT happen is well within the natural variability of global conditions during this interglacial.
Peter Foster says:
May 26, 2014 at 11:14 am
The temperature of the water under the Ross Ice shelf and under the sea ice is -1.96°C – the freezing point of sea water. The glacial ice coming off the land into the sea is pure water with a melting point of 0°C. Therefore unless the water temperature rises above 0°C then there will be no melting.
Seconded by:
tim maguire says:
May 26, 2014 at 11:57 am
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Sorry, ice melts and freezes at the same temperature, given seawater of the same composition. In fact melting ice reduces the local salinity while freezing increases it, so it does have to be a little cooler to freeze than to melt.
As for this grounded ice behaving like floating ice, that’s pretty silly, but as someone noted, reducing perimeter ice should cause the perimeter to rise, reducing the slope. The models probably take this into account. Or do they?
More pertinent questions are, to what extent is glacial behavior a response to the end of the LIA, and to what extent is it a response to the end of the last big ice age. Ice is a good insulator, flow rates are temperature dependent, and it takes a real long time for ice to warm up or cool down. Ultimately any news of warming is good news–the longer we have to wait for the next LIA or BIA, the better. –AGF
agfosterjr says;
“Sorry, ice melts and freezes at the same temperature, given seawater of the same composition” and
“As for this grounded ice behaving like floating ice, that’s pretty silly”
Perhaps I misunderstood you.. The point is that the melting point of ice is 0°C but the water under the ice is -1.96°C – therefore no melting. Glacial ice is formed on the land from accretion of water vapour in the air plus the rare snow fall. (The annual precipitation at the head of the Wright Valley in 1985 for example was 5mm but there is also the possibility that some of that was simply blown snow from the Polar Plateau)
Sea Ice on the other hand is formed from sea water and your comment re salinity is correct but sea ice still contains a lot of salt – try melting it for drinking water – well you will only try once.
Re sea ice holding back the flow of glacial ice – this is quite obvious. Many smaller glaciers have a fluted appearance due to winter sea ice slowing the glacier and causing the snout to broaden and thicken during the winter and then flow more quickly in the summer when the sea ice has melted. The Ice shelves are glacial ice and in bays their snouts float and accumulate to form the shelves. The Ross Ice Shelf is about 350 m thick at the front and definitely holds back its contributing glaciers. It has also totally broken out during every past interglacial with the exception of this one and since we are headed back into the ice age (look at the declining temps of Minoan, Roman, Medieval and Modern warm periods in the GISPII ice cores) it probably wont break out.
These papers were submitted in Nov. and Dec. of 2013. A new volcano was discovered under the ice in the same general area in Nov. 2013. The outflow of melt water from that volcano would be upstream of this area.
It is likely these papers had been completely written before the volcano was known to exist. Would that change the papers? Since the warm water upwelling is a computer modeled claim I think the chances that is really true is questionable. Now, if you were a betting man what would you think is the most likely cause of the melting?
Peter Foster says:
May 27, 2014 at 9:50 am
“The point is that the melting point of ice is 0°C but the water under the ice is -1.96°C – therefore no melting.”
======================================================================
I repeat, melting point=freezing point. Period. Your statement is utter nonsense. At -2°C (depending on salinity) ice and water are at equilibrium. Add energy, ice melts. Remove energy, ice freezes. This is done through the slightest T changes, like the ice cubes in the pan experiment.
“Sea Ice on the other hand is formed from sea water and your comment re salinity is correct but sea ice still contains a lot of salt – try melting it for drinking water – well you will only try once.”
=======================================================================
Sea ice has little to do with the immediate problem. When glaciers hit sea water they don’t freeze–they melt. The water temperature is governed by glacier melt. The melting lowers near surface T till it reaches equilibrium. Warmer water must be brought in to continue the melting. Polar water has a negative thermocline near the surface. Warmer saltier water lies under the cold fresh water. Because of melting. –AGF
Is it me, or has NASA gone from sending people to the moon to simply barking at it?
Dr. Det Riedel says:
May 27, 2014 at 7:02 am
Are there any seismic activities? The reason I ask is that all other land masses move North, only Antarctica is stagnant at the moment…
——————————————————————————————————
There were three 5+ quakes to the east of the peninsula around 9 days ago. They hit at a triple junction where a west to east connector between the main north/south fractures of East Pac/Mid Atlantic are joined to the only fault that leads into Antarctica. That fault line leads directly to the tip of the peninsula. My impression of it is that the movement shows Antarctica shifting to the west vs the upper plates. This has led to the easterly drift of the fracture line coming off of the tip of the peninsula. The triple junction sits closer to the Mid Atlantic fault line, and to the east of the peninsula.
If you live on the Florida coast, panic. If you live on the California coast next to Al Gore, no worries.
How’s this for a new theory: Glaciers are the earth’s automatic balancing mechanism. They advance and retreat as necessary to hold down the “wobble” in our spin. Right now, there are just too many people in China and it threw us “out of balance”. So some of the glaciers had to retreat while others had to advance. I calculate that if we move just a couple million, tightly packed Chinese into Al Gore’s neighborhood, all the glaciers will stop in their tracks, the sun will shine, birds will sing and Democrats will lie down with Republicans. Al will just have to suck it up.