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)
Of course the melting glaciers result in isosatic rebound of the land in exactly the proportion to the ice loss – like in Norway and the sea basin deepens. They make this correction for sea level so why not do that when it is happening in the WAIS.
I know of no coastal infrastructure that was not rebuilt several times since the Napoleonic Wars.
Also, that last remark about Florida deserves attention. Is a there a large scale real estate scam in the works? Who’s going to buy there at those splendid depressed prices?
see: Miami Herald / Rising sea levels, falling real estate values
The definition Guy 12:14 pm
I think your son should shoot higher. He has all the qualifications needed to be a Democratic presidential nominee.
Eugene WR Gallun
Yes, this researcher has a problems convincing people that the sea is rising especially since satellites say there is no problem. This person can’t or doesn’t want to believe that that the coast can sink therefore making it appear that the sea level is rising!
Logic problem
The authors are quoted “We find no major bed obstacle upstream of the 2011 grounding lines that would prevent further retreat of the grounding lines farther south,”
……….
This can mean that the ice in question has changed, or is changing, from resting on bedrock to resting on water. As often stated, ice melting from floating on water hardly changes sea levels (Archimedes) whereas ice melting from above bedrock does change sea levels.
Has anyone modelled to transition from grounded to floating and any changes in sea level produced?
There is a confirmation bias going on in each of these “research scientists” who have been loking for this evidence since 2001-2002 timeframe. Who is their check and balance? What is their quality assurance? They have been sitting around tables and classrooms and labs looking for this very paper 9writing this paper and its antecedents since 2002-2005. Of course they will say nothing to contradict their peer group!
Apparently their logic is as follows: Leading edge of glacier is underwater, stuck on a rising underwater ridge. This blocks ice movement “upstream”, so upstream ice piles up and blocks the sea between the underwater ridge and the continental shelf. This blocks ice uphill on the continental mountains, which then backs up further uphill. Thus, in their minds, if you remove the single blockage at the underwater ridge, then EVERYTHING begins sliding downhill and melts and the sea level rises and we have to sell property in Florida.
As evidence, we have all of their carefully timed press releases with the national administrations’ National Climate Ass., the EPA’s July 2 new restrictions on coal and a tripling of electricty prices, new EPA requirements on gasoline that increase gas and food prices, new drought regulations coming from California, etc. And all timed before the 2014 November elections and the 2015 Paris energy agreements.
SO, how much area does the WAIS actually represent?
How much of the three glacier is over the water, and how much is on land?
What are the thickness of the three WAIS glaciers over water, and what is the percent thickness over that part is on land? What is the top of ice altitude of the three glaciers?
How fast are the three glaciers actually moving? How fast are they moving BEFORE the past 20 years of movement?
How much area of each of the three glaciers is actually moving at what speed now, and how much is … well, not moving at all? How much ice is actually blocked by this very small! little area of deep water under the glacier? (Yes, there is deep water between the underwater ridge and the grounding line, but the deep areas are only a few hundred square km^2.)
Where does the “warm water” come from that is supposedly melting the toe of the three glaciers deep underwater, if the edge of the Antarctic Sea Ice for the past three years been consistently hundreds of kilometers further out to sea from the edge of the three glaciers?
It takes time – 50 to 100 years! – for a single piece of ie falling as ice at the top of the Pine Island glacier to move downhill and over the sea and then to the toe of the glacier at the grounding line? If the grounding line is moved by 10 kilometers, what is their justification in stating melt rates that require that the travel time will suddenly become 10 or 20 years?
If the toe of the glacier melts out, why do they assume that the glacier ice immediately behind the tiny melted region will not just spread out and immediately replace the melted toe of ice ?
ehtyler says:
May 26, 2014 at 12:19 pm
I just returned from an inside passage/Alaskan cruise aboard the Coral Princess. The view of Glaciers in Glacier Bay and the College Fjord were breathtaking but, the continual recitation of the government view that Glaciers were melting because of human activity resulting from climate change, warming of the air and sea, was enough to nauseate anyone with the ability to both read and think.
Took that itinerary a couple years back on another line and the day cruising in glacier bay was awesome! The biggest surprise to me was the sound of the glaciers at their face – up close it sounded exactly like a thunderstorm with the “cracking” of close lightning followed by the booming thunder. I had never heard of that before concerning glaciers and it was a surprise. The unpleasant surprise was the same as yours… supposedly well educated park rangers spewing pure unadulterated nonsense to everyone about how man is destroying these beautiful glaciers by using fossil fuels. Amazingly the talk at the dinner table that night seemed to indicate that everyone pretty much thought they were full of it.
The “fear” here is simply a failure to pay attention to history. Ocean levels have been overall much higher than now, and much lower than now, in the relatively recent (10k years) past. The lure of building on the coastlines is just too great to worry about such things. There’s no reason to worry about it now. It’s going to happen (or not) eventually. And if ocean levels drop, people will continue to build closer to the receding water. Live and learn (or not).
“It’s gone over the tipping point, and there’s no coming back,”
Whew! For a while there I thought we would have to keep funding them.
Now that we know what’s happening and whats going to happen.
Future funding is unnecessary.
Right?
the grounding line over at the Ross Ice Shelf has been retreating at an average rate of 120 ft/year for the last 7600 years…no different from the modern rate. I’d wager that these West Antarctic ice shelves are doing something similar
The Sea Ice Index page shows that the sea ice on the west side of Antarctica has been in a decline, but you can see that the rest of the coastline, almost 80% of total, has been increasing. Isn’t that mainly due to Drakes Passage constricting the westerly flow? Last years sst anoms for the region were well above average. Looking back to Jan 2013, there was a large region of surface flow that was +2 to +3 above normal. This large area was tucked in fairly close to the continent, with the main body just to the west of Drakes Passage. It stayed like that till the end of June 2013, which is when the rate of growth of the ice shield took a big jump and was off to the races and a new record high. Ever since then, Antarctica has remained surrounded by – sst anomalies. When the next large warm sst area formed again it ended up residing and still resides about a 1/4 of the way up the west South American coast, well north of its earlier position. Will this lead to a change in the melt rate on the WAIS and points west? How current is the data in these projections which form the basis for their claim?
I have some questions about the net effect of all this on sea level rise, i.e., the mass balance.
Glaciers move usually because more weight, i.e., snow, is piled onto the upper parts of the glacier and gravity causes it to flow. Were does the snow come from? Evaporation from the ocean which reduces sea level.
In West Antarctica, the glaciers are “grounded” below sea level and are therefore displacing ocean water. Since water as ice has more volume per weight than liquid water, melting of “grounded” ice should also decrease sea level.
Floating ice already displaces its weight with an equal weight of water so the net effective on sea level of melting floating ice is near zero.
Only ice/snow that was always above sea level could raise sea level once it melted into the sea. How much is that compared to the evaporated water which produced the ice/snow on the upper parts of the glacier in the first place? What is the mass balance?
The definition Guy says:
May 26, 2014 at 12:14 pm
————————————————————–
Absolutely brilliant!!!!!
Brought a smile and a chuckle.
nice work.
cn
OK,let us assume your comment is right – we have, after all, no reason to doubt it.
120 feet/year = 36.5 meters/year.
What if the current grounding line – that “depth of water” where the glacier ice (assumed equally deep all the way across a 30 kilometer wide moving stream of ice!) hits the bedrock and “stalls out” thereby blocking the ice upstream from moving further. What if the grounding line is “retreating upstream” into deeper water because the glacier ice coming “downstream” is just a little bit deeper now?
Assume for example, that the undersea bedrock has a 1:20 slope at today’s grounding line.
Thus, if the edge of the flowing glacier ice is not melting underwater, but is now 2 meters deeper than it was last year, then the glacier ice would “stop” 40 meters further away from the reference point. 40 meters closer to the continental land mass. Remember, in these three glaciers, the sea gets deeper little ways away from the original shoreline, then gets shallower again as you get further out. it is this “shallow area” where the WAIS is claimed to be grounding out. The glacier would appear to be “retreating” when it fact it actually is deeper and heavier and has more ice than it is “supposed to have” .. but would be 40 meters further “retreated” ….
Theo Goodwin says:
May 26, 2014 at 12:39 pm
‘“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.’
Aha, a wolf among sheep. A skeptic among believers. How long before Wolovik is shunned?
———————————————————–
I wonder what his twitter page looks like.
They don’t pull punches these tolerant folks.
My guess is he may not last the week before his co-authors pull their names.
At least Jacobs was smart enough to cover his backside:
“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.”
And they may well be looking to further their own causes.
cn
Latitude says:
May 26, 2014 at 2:45 pm
Catcracking says:
=====
“The West Antarctic Ice Sheet is mostly grounded on land that is below sea level”
pretty much…so when it does collapse it’s also going to defy the laws of gravity
——————————
Oh noes! It’s worse than we thought.
cn
Nice balance in the projected collapse of the ice sheets there.
Just short enough that the public can still feel uncomfortable with the idea of the collapse of what seemed fixed in perpetuity ice sheets.
Just long enough to comfortably see out the researchers working lives and collect their munificent funding until the end of their working lives plus collect their generous retirement benefits.
And just far enough into the future for them to be good and dead so as not have to explain to the public who paid them for this crap, why the ice sheets didn’t catastrophically collapse as they so blatantly predicted.
Climate science is no longer science of any description.
It has degenerated into a non stop chicken entrails based model prediction and divination process of trying to foretell the future.
This from a formerly respected branch of a modern civilisation, that of science, that has in the past gone to great lengths to denigrate and disparage the predictions and divinations of the ancient’s Oracles as based on nothing more than complete ignorance and a deliberate and sophisticated obfuscation so as to hide the lack of ability to foretell the future but still collect the lucrative payments for the Oracle’s divinations..
Climate alarmist science of which the “predictions” for a catastrophic collapse of the Antarctic ice sheets are just another example, is nothing more than the equivalent of the ignorance based predictions for future events that emanated from the oracles and shamans of the ancients.
And maybe those ancient Oracles were a good deal more accurate in their predictions than today’s climate science as those predictions and divinations were made after considerable care was taken to surreptitiously try and exam any factors that might underlay an Oracle’s predictions so the priests could translate the Oracles stutterings to be in line with the expectations of the funders of the Oracle’s divinations.
It al sounds horribly familiar doesn’t it?.
The predictions, pronouncements and quite deliberate obfuscation’s of Climate Science today all sound awfully familiar to anybody who knows a little of the history of those ancient Oracle’s divinations and predictions.
And 2500 years later climate science’s predictions carry about as much or maybe even less credibility than those old Oracle’s predictions and divinations.
All long range predictions should come with a disclaimer that explains the law of accelerating returns as it applies to technology.
A further thought. Please check my logic and geometry here, surely these “scientists” would not have missed this.
They claim the WAIS (actually, three glaciers feeding from the WAIS, or 5% of the WAIS ice itself) are retreating catastrophically.
Fine.
They claim the “retreating” is due to, or a symptom of, or is occurring simultaneously with, or is measured by a “retreat of the grounding line” towards deeper water. This deeper water is between the original grounding line, and the original continental bedrock at the original shoreline way back upstream of the glacier.
OK, fine.
So … If the moving glacier were melting on the bottom (due to an assumed “warmer water” current getting blown in somehow underneath 450 – 550 kilometers of packed antarctic sea cie!) then the glacier ice would be shallower at least near the tip, right? If not shallower completely across the toa of the glacier, it would be weaker or less consistent and less able to resist the relentless pressure
pushing down from the billions of tons of glacier ice higher up (further away from the grounding line), right?
So, if the bottom “toe” of the glacier were melting and were weakening or were disappearing completely, would not that relentless force of the upstream glacier ice FORCE the tip of the glacier to move DOWNSTREAM and further away from the continental sea coast? If it were melting underneath, then it would be shallower, and the glacier would move further UP the shallow slope of the grounding line bedrock?
So, the shallower the glacier ice -> the less ice there is underwater -> for the same force pushing the glacier “downstream” the tip of the glacier must be expanding (getting longer!) or getting pushed further “up” the sloping bedrock underwater -> the further forward the top of the glacier must be observed!
The deeper the glacier ice, the quicker it hits the sloped grounding line underwater, the further BACK the glacier is touching the grounding line bedrock, and the further back the “top” of the glacier appears to be moving.
The definition Guy says:
May 26, 2014 at 12:14 pm
Your son is indeed well equipped for success in the 21st century.
Unfortunately.
God only knows
God makes his plan
The information’s unavailable
To the mortal man
We work in our jobs
Collect our pay
Believe we’re gliding down the highway
When in fact we’re slip slidin’ away
The inevitability of the WAIS collapse came with the rise of the 120 m ocean rise 8000 yrs bp.
But what really scares the Liberals is the inevitability of the collapse of the US discretionary budget due to the Great Society healthcare and welfare programs unleashed in 1965. As those gorillas grow, their appeptite for tax revenues are set wipe out US government discretionary spending, which includes grant funding for science research within 2 decades.
Rather than dismantle those Great Society programs, climate change alarmism is needed to gain support for new taxes. Liberals are unable to prioritize cuts. thus a way must be found to keep paying for everything. Carbon tax anyone?
I had always heard that a glacier that is advancing is advancing because it’s growing and a glacier that’s retreating is one that’s basically melting. What is it with these guys? And a glacier grounded on land (does it really make any difference if it’s below sea level?) is held back from a further advance (which would somehow be considered a collapse?), not by the land, no, by ice floating on the sea? And a 0.8 degree Centigrade increase in air temperature magically found its way through the surface and into the Southern Ocean (at a 1,000 to 1 density ratio) so as to melt that floating (stable, huh?) sea ice barrier.
Ok, I just got home from watching Godzilla. And it taught me that if you see a movie go to a movie made by people who know how to make movies. You’ll get your money’s worth and I think I got my money’s worth. Not with the above science fiction however. Why is NASA investigating glaciers anyway? I think the problem is that NASA stands for National Aeronautics and Space Administration but, since they’ve now got to hitch rides from the Russians, they’ve branched out into the inner space between the gullible public’s ears.
And I’m 6′ 4″ and in my sixties and I’m taller on average this last 5 years than all the preceding 5 year averages put together so I’m gunna be a giant among men. Either that or a Big Climate guru.
Wayne Delbeke says:
May 26, 2014 at 2:49 pm
“I was in Glacier Bay a few years ago and picked up a National Parks Services brochure. It actually noted that “glaciers advance and glaciers retreat”. They show NO Glacier Bay in 1680, then a rapid advance of the glaciers in the Little Ice Age around 1750 that scoured out and created Glacier Bay; then the subsequent retreat. I was surprised to see ‘real’ information based on geology and verbal history in the brochure. The pertinent information from the Brochure is here:
http://tinypic.com/r/2me7e5j/8 ”
It’s great to see that in their brochure, that’s nice, but here is what is on their website:
http://www.nps.gov/glba/naturescience/climate-change.htm
It’s on every National Park website and just about every Government website, in the schools and universities, k-12, the Main Stream Media, the US administration – it’s settled, we have lost the battle of truth in climate – get over it – lets go on to other issues.