The wailing today is that the collapse of the Antarctic ice sheet has already begun.
It’s pretty bad when other environmental reporters start calling you out on it, such as NYT’s Andrew Revkin did today.
Awful misuse of "Collapse" in headlines on centuries-long ice loss in W. Antarctica. See rates in papers. Same as '09 http://t.co/kk48ztySvZ
— Andrew Revkin 🌎 ✍🏼 🪕 ☮️ (@Revkin) May 12, 2014
Yes, a slow affair indeed. Truly an abuse of the headline. Buried below the headline in the article, there is agreement with Revkin:
But the researchers said that even though such a rise could not be stopped, it is still several centuries off, and potentially up to 1,000 years away.
A lot can happen in several centuries, why even in the last couple of years Antarctic has seen record levels on Antarctic sea ice.
And the temperature isn’t cooperating either:
RSS Southern Polar Temperature Lower Troposphere (TLT) – 1979 to Present for the area where sea ice forms (60 to 70S)
Remote Sensing Systems (RSS) – Microwave Sounding Units (MSU) – Click the pic to view at source
[previous graph removed – wrong latitude span and no replacement, my mistake -Anthony]
UPDATE: Revkin gives more reasoning on “collapse” here:
Consider Clashing Scientific and Societal Meanings of ‘Collapse’ When Reading Antarctic Ice News
Here is the paper the claim is based on:
Widespread, rapid grounding line retreat of Pine Island, Thwaites, Smith and Kohler glaciers, West Antarctica from 1992 to 2011.
Abstract
We measure the grounding line retreat of glaciers draining the Amundsen Sea Embayment of West Antarctica using Earth Remote Sensing (ERS-1/2) satellite radar interferometry from 1992 to 2011. Pine Island Glacier retreated 31 km at its center, with most retreat in 2005–2009 when the glacier un-grounded from its ice plain. Thwaites Glacier retreated 14 km along its fast-flow core and 1 to 9 km along the sides. Haynes Glacier retreated 10 km along its flanks. Smith/Kohler glaciers retreated the most, 35 km along its ice plain, and its ice shelf pinning points are vanishing. These rapid retreats proceed along regions of retrograde bed elevation mapped at a high spatial resolution using a mass conservation technique (MC) that removes residual ambiguities from prior mappings. Upstream of the 2011 grounding line positions, we find no major bed obstacle that would prevent the glaciers from further retreat and draw down the entire basin.
And here is the press release from AGU:
New study indicates loss of West Antarctic glaciers appears unstoppable
12 May 2014
Joint Release
WASHINGTON, D.C. — A new study finds a rapidly melting section of the West Antarctic Ice Sheet appears to be in an irreversible state of decline, with nothing to stop the glaciers in this area from melting into the sea.
The study presents multiple lines of evidence, incorporating 40 years of observations that indicate the glaciers in the Amundsen Sea sector of West Antarctica “have passed the point of no return,” according to glaciologist and lead author Eric Rignot, of the University of California Irvine and NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, California. The new study has been accepted for publication in Geophysical Research Letters, a journal of the American Geophysical Union.
These glaciers already contribute significantly to sea level rise, releasing almost as much ice into the ocean annually as the entire Greenland Ice Sheet. They contain enough ice to raise global sea level by 4 feet (1.2 meters) and are melting faster than most scientists had expected. Rignot said these findings will require an upward revision to current predictions of sea level rise.
“This sector will be a major contributor to sea level rise in the decades and centuries to come,” Rignot said. “A conservative estimate is it could take several centuries for all of the ice to flow into the sea.”
Three major lines of evidence point to the glaciers’ eventual demise: the changes in their flow speeds, how much of each glacier floats on seawater, and the slope of the terrain they are flowing over and its depth below sea level. In a paper published in Geophysical Research Letters in April, Rignot’s research group discussed the steadily increasing flow speeds of these glaciers over the past 40 years. This new study examines the other two lines of evidence.
The glaciers flow out from land to the ocean, with their leading edges afloat on the seawater. The point on a glacier where it first loses contact with land is called the grounding line. Nearly all glacier melt occurs on the underside of the glacier beyond the grounding line, on the section floating on seawater.
Just as a grounded boat can float again on shallow water if it is made lighter, a glacier can float over an area where it used to be grounded if it becomes lighter, which it does by melting or by the thinning effects of the glacier stretching out. The Antarctic glaciers studied by Rignot’s group have thinned so much they are now floating above places where they used to sit solidly on land, which means their grounding lines are retreating inland.
“The grounding line is buried under a thousand or more meters of ice, so it is incredibly challenging for a human observer on the ice sheet surface to figure out exactly where the transition is,” Rignot said. “This analysis is best done using satellite techniques.”
The team used radar observations captured between 1992 and 2011 by the European Earth Remote Sensing (ERS-1 and -2) satellites to map the grounding lines’ retreat inland. The satellites use a technique called radar interferometry, which enables scientists to measure very precisely — within less than a quarter of an inch — how much Earth’s surface is moving. Glaciers move horizontally as they flow downstream, but their floating portions also rise and fall vertically with changes in the tides. Rignot and his team, which includes researchers from UC Irvine and JPL, mapped how far inland these vertical motions extend to locate the grounding lines.
The accelerating flow speeds and retreating grounding lines reinforce each other. As glaciers flow faster, they stretch out and thin, which reduces their weight and lifts them farther off the bedrock. As the grounding line retreats and more of the glacier becomes waterborne, there’s less resistance underneath, so the flow accelerates.
Slowing or stopping these changes requires pinning points — bumps or hills rising from the glacier bed that snag the ice from underneath. To locate these points, researchers produced a more accurate map of bed elevation that combines ice velocity data from ERS-1 and -2 and ice thickness data from NASA’s Operation IceBridge mission and other airborne campaigns. The results confirm no pinning points are present upstream of the present grounding lines in five of the six glaciers. Only Haynes Glacier has major bedrock obstructions upstream, but it drains a small sector and is retreating as rapidly as the other glaciers.
The bedrock topography is another key to the fate of the ice in this basin. All the glacier beds slope deeper below sea level as they extend farther inland. As the glaciers retreat, they cannot escape the reach of the ocean, and the warm water will keep melting them even more rapidly.
The accelerating flow rates, lack of pinning points and sloping bedrock all point to one conclusion, Rignot said.
“The collapse of this sector of West Antarctica appears to be unstoppable,” he said. “The fact that the retreat is happening simultaneously over a large sector suggests it was triggered by a common cause, such as an increase in the amount of ocean heat beneath the floating sections of the glaciers. At this point, the end of this sector appears to be inevitable.”
Because of the importance of this part of West Antarctica, NASA’s Operation IceBridge will continue to monitor its evolution closely during this year’s Antarctica deployment, which begins in October. IceBridge uses a specialized fleet of research aircraft and the most sophisticated suite of science instruments ever assembled to characterize changes in thickness of glaciers, ice sheets and sea ice.
For additional images and video related to this new finding, visit: http://go.nasa.gov/1m6YZSf
For additional information on the West Antarctic Ice Sheet and its potential contribution to sea level rise, visit: http://go.nasa.gov/1oIfSlO
For more information on Operation IceBridge, visit: http://www.nasa.gov/icebridge
###
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Wrong, Bob, my logic is impeccable but your reading comprehension is deficient.
You are not understanding either the sentences in the head posting or the clear statement in my comment. The thread is clearly about discrepancies and exaggeration comparing the authors’ claimed results of the study with the hysteria of the Guardian deadline and article.
That is why my statement said “putative scientific facts.”. Assume the Abstract’s summary of the study’s findings to be correct. Does the Guardian headline and article provide an accurate and precise summary, or not?
This is a perfectly legitimate activity, taking the summary which the study’s author provide and assessing whether or not the journalists have given an appropriate review of the findings.
You are free to compare the Abstract in detail with the contents of the paper(s) (which you have yet to do here, since you prefer cheap shots at Anthony and the commenters). The thread (and my comment) OBVIOUSLY refererence the journalistic exaggerations of the authors’ own summary of their study. Consider the plain meaning of Revkin’s statement quoted near the top of the thread:
I know two polar ice experts. The new study doesn’t contain anything that they haven’t been saying for years.
So…. it all depends on the meaning of “collapse”, right?
/snark
These climate alarmists have no credibility predicting weather in the short term so they have now picked a time frame that is more safe for them, namely a 1000 years away. Unable to predict even the next season (as we saw with the last US and UK winter predictions and the 17 years of global temperature pause instead of unprecedented warming , they are now grasping at straws with even worse predictions .
Seems like we have two problems here: (1) the authors need to go back to Glaciology 101 and learn how glaciers work, and (2) the journalists need to stop hyping things they know nothing about. Keep in mind we’re talking here about a small part of the glacial system of West Antarctica which makes up a tiny fraction of the total glacial ice in Antarctica. This is not the main Antarctic ice sheet, which is the East Antarctic glacier.
What glaciers do is determined by the amount of accumulation of ice and snow in their upper parts and the amount of ice lost in their lower parts. The terminus of a glacier that ends in the sea can be affected by changes in the position of the grounding line (the place where sea water reaches beneath the glacier and separates the glacier from its bed. The entire glacier is NOT controlled by the position of the grounding line. Shifts of the grounding from time to time occurs also in Alaskan glaciers and what happens is the calving rate goes up and a section of the lower glacier may break up until a new grounding line is established. The terminus of the glacier then stabilizes and the effect is not felt in the upper reaches at the glacier source. These folks seem to think that a glacier is controlled by its grounding line (like a stopper in a bottle) and if it moves the entire glacier will slide into the sea! Nonsense. What will probably happen to these four small glaciers is the position of the grounding line will simply move upstream a bit, re-establish, and the glaciers will stabilize at the new terminal position. The West Antarctic ice sheet is NOT collapsing, the retreat of these small glaciers is NOT caused by global warming (neither the globe nor Antarctica have warmed in almost 18 years), and sea level is NOT going to rise 10 feet.
As for journalistic hype, the only thing you can say is that it’s total crap. The Guardian hype is laughable–all they have done is destroy what is left of their credibility. The NY Times continues to lose its credibility with Gillis’s statement:
“The finding, which had been feared by some scientists for decades, means that a rise in global sea level of at least 10 feet may now be inevitable. The rise may continue to be relatively slow for at least the next century or so, the scientists said, but sometime after that it will probably speed up so sharply as to become a crisis.” (Gillis, NY Times)
Some calving of the termini of these four small glaciers is not going to raise sea level 10 feet–
the rise of sea level will continue at about 7 inches per century and we will see little, if any, effect from changing the grounding line of these glaciers.
The most likely cause seems to be geothermal and not warm sea water. https://news.wustl.edu/news/Pages/25611.aspx Didn’t know there is a rift between E & W Antarctica.
Until the retreat in the grounding lines halt this is something to monitor closely. There is only a 5% chance of collapse in 200 years but I have witnessed how fast volcano’s can change topography at Mt St Helen’s.
More of the lazy MSM blogging from Adelaide South Australia-
http://www.adelaidenow.com.au/technology/antarctic-ice-sheet-collapse-unstoppable-scientists-say/story-fnjww4h6-1226915299389
And they wonder why newspapers are dying? Perhaps they need to comprehend why that’s become unstoppable in a lot less than 200 or a 1000 years?
Don Easterbrook says:
Don, you can’t compare WAIS with Alaskan glaciers. The WAIS sits on a basin that is up to 2500M below sea level. Once water gets between the land that anchors the glacier its flow can increase. This is what is being measured. The rates of flow have increased likely due to a lack of impingement at the grounding lines. No scientists are claiming the glaciers will collapse into the sea in a rapid manner. Just that the rate of loss will continue to increase due to positive feedbacks.
Don Easterbrook says: What will probably happen to these four small glaciers is the position of the grounding line will simply move upstream a bit, re-establish, and the glaciers will stabilize at the new terminal position.
Based on what? What are they going to re-establish and stabilize on? This is nothing like Alaska. The bedrock is below sea level and deepens as you go “inland”. The surface area of ice exposed to ocean water grows as the grounding line retreats. The process is described here:
http://www.nasa.gov/jpl/news/antarctic-ice-sheet-20140512/
Instead of sweeping one-size-fits-all statements about how glaciers behave, a response to what is actually being observed and discussed in West Antarctica would be more appropriate.
conscious1 says: The most likely cause seems to be geothermal and not warm sea water.
There is volcanic activity in the area, but it appears to be too localized to explain the changes observed along the length of the Amundsen Sea coast of West Antarctica. From the British Antarctic Survey:
http://www.antarctica.ac.uk/press/press_releases/press_release.php?id=341
And somehow you are trying to imply that the WAIS touches that 2500 meter-deep ocean floor somewhere under the WAIS? Nonsense.
Also, “This is what is being
measuredromanticized/predicted/publicized/propagandized.”You need to present a few simple facts, since you are trying to defend this propaganda as your religious acolytes write papers supporting their funding sources in their administration’s bureaucracies ….
What is the actual cross-section of the ocean floor from sea level out to the continental shelf under the WAIS?
What is the cross-section of the WAIS from top-of-mountain (inland, where WAIS thickness = 0.0 meters), out to the continental rock at sea level, out to the furthest edge?
What is the height of the WAIS at the 0,0 sea level intersection of the WAIS and the continental rock?
What is the height above sea level, and below sea level of the WAIS at its furthest edge?
What is the depth of the ocean floor under the WAIS at its furthest edge from the continental rock?
(See above, obviously.)
These so-called “scientists” writing for publicists and bureaucrats sucking the public tax dollars for their endless funding and energy control programs are similar to those who claim the Greenland ice sheets will “slide off into the sea” … when the central Greenland ice caps are sloped off of mountainous rings around Greenland that force the ice sheet back AWAY from the sea. Who predict in their publicity that Greenland glaciers (the tiny, short 50 kilometers around the OUTSIDE of Greenland’s mountains predict the behavior of the massive 1000 kilometer-wide central Greenland ice sheets.
RACookPE1978 says: “A few facts, since you are trying to defend this propaganda”
I’m not defending any propaganda. The media portrayal of this issue is absurd.
This issue has been studied since 1968 and the observed retreat of grounding lines, thinning of glaciers and increase in their flow rates is empirical evidence that this is a potentially unstable system. I think the authors are making some assumptions about future warming and I wonder if global cooling could reverse this trend but the fact is that water has come between below sea level grounding lines.
Are you going to deny the physically measured evidence because the media has wildly overblown the issue?
sure thing leo, it isnt the KNOWN HEAT coming from the volcano doing the melting it clearly has to be the HUMAN caused heating that we CANT FIND!
Not to be outdone in the alarming new department, NASA piles on:
http://science.nasa.gov/science-news/science-at-nasa/2014/12may_noturningback/
conscious1 says:
May 13, 2014 at 8:43 am
(criticising Don Easterbrook says:)
Don, you can’t compare WAIS with Alaskan glaciers. The WAIS sits on a basin that is up to 2500M below sea level. Once water gets between the land that anchors the glacier its flow can increase. This is what is being measured.
—————————————————
We are not to compare WAIS with Alaskan glaciers because (description of WAIS) WHEREAS (missing) (description of Alaskan glaciers)(missing).
Half a contrast is no contrast.
The same with the next sentence; the preposition ‘between’ needs an ‘and’ to make any sense.
We are left to infer what is meant in an incoherent sentence.
AFAIK, the termini of the glaciers in Prince William Sound are sitting on rock that is below sea level. They’re able to advance further as long as the terminal moraine prevents the sea from under-cutting the glacial snout. Eventually, the waves win and rapid retreat occurs. Once the terminus retreats to shore, the end moraine begins to reform and the glacier can advance.
Glaciers Columbia and Meares are only a few miles apart and yet one is strongly retreating and the other strongly advancing. Numerous other tidewater glaciers are known to have undergone multiple cycles of retreat and advance of tens of miles in the past.
“New study indicates loss of West Antarctic glaciers appears unstoppable”
If it’s unstoppable, there’s nothing we can do, right?
So let’s stop all the whining and demanding our money and just enjoy the (thousands of years of) life we’ve got left. 😀
Criticism for alarmism here should go to the paper’s author, not the Guardian, since Rignot used it in the press release – interview process:
“The collapse of this sector of West Antarctica appears to be unstoppable,”
Authors sometime have a hard time sticking to the text of their own papers.
mebbe says: -Yea my grammar sucks. Are you an English teacher?
You have a valid point about the termini of Alaskan glaciers but all of those originate above sea level. Once they retreat to land the ocean can’t continue to undercut it. The WAIS has no such limitation. That is why you can’t compare the two systems.
Until there is evidence that the retreat in grounding lines has stopped their theory of unstoppable loss has support. I think they are making linear projections based on limited data. It may be natural for grounding lines to retreat and advance there but the limited window of observation only shows rapid retreat.
It is my understanding that there is a scientific difference between land-ice and sea-ice. Is that understanding correct?
Doesn’t that seem like something that should be explained to us common-folk? Can we have a primer on how those two separate ice-bodies act? i.e. I’m assuming sea-ice melts and freezes every year while land-ice is slightly more permanent. Or is this incorrect? Anyway, it sounds like land-ice may be melting at a rate that is greater than historical trends. Is that true? It sounds like sea-ice is growing at a rate higher than historical trends. Is that true?
So . . . am I to understand that large glacial flows in the West Antarctic are flowing UPHILL as a result of CAGW?
Hmmm . . . this new learning amazes me.
Jacob says: Your understanding is correct.
There is a theory that states the increase in Antarctic sea ice is because of all the fresh water floating on top as a result of the melting of WAIS. I would love to know if this theory has any validity. I have been using Antarctic ice extent as proof CAWG fears are overblown for years. If the theory is correct I have been wrong about it being proof of a lack of warming.
conscious1,
It’s a very typical (but, to my mind, bizarre) assumption that only teachers appreciate perspicuous prose. I sure ain’t one and I don’t consider myself gratuitously pedantic, either. I just begrudge having to re-read a sentence because solecisms have made it ambiguous or undecipherable.
Many grammatical mistakes don’t confuse one too much but sometimes just an excess apostrophe can lead you down the wrong path for several words.
Anyway, there’s much about the descriptions of the dynamics of the WAIS that strains my credulity.
Bob Kutz says:
May 13, 2014 at 12:27 pm
“So . . . am I to understand that large glacial flows in the West Antarctic are flowing UPHILL as a result of CAGW? ”
No, the WAIS reaches heights of 3000M above sea level. The theory is that below sea level water is getting under the ice sheet making it flow faster. I believe it to be very dishonest blaming human emissions as the cause.
“And there’s not any significant warming over the entire continent, as it is nearly flat as well (from 70S to the pole” …
That graph looks like there has been no warming, even a decline, in the recent decade. So it is “nearly flat” if you start at the left, but, using Christopher’s technique, starting at today, and working backwards as far as you can go, while still keeping the slope of the trend line at zero or negative… it will go back a ways… no recent warming, even cooling in recent times
Or, to look at this another way, here is what should have been the headline for this story;
“One of the most striking features is they have been reacting almost simultaneously. We do think this is related to climate warming.” — lead author of the study Eric Rignot, glaciologist at the University of California, Irvine, and NASA’s Jet Propulsion Laboratory in Pasadena, Calif.
If it hasn’t anything to do with warming then it necessarily has nothing to do with anthropogenic warming.
The next time you see a news story that screams about Antarctic ice bergs floating in the southern oceans are a sure sign of global warming – show them this.
Someone at the Guardian recently suggested that global warming sank the Titanic. It was pointed out that ice-bergs at that time so far south were a sign of cooling. She backed down a little but kept pointing to her source. She forgot to read the caveats there.