A Terrifying Sea-Level Prediction Now Looks Far Less Likely
But experts warn that our overall picture of sea-level rise looks far scarier today than it did even five years ago.
ROBINSON MEYER
JAN 4, 2019
One of the scariest scenarios for near-term, disastrous sea-level rise may be off the table for now, according to a new study previewed at a recent scientific conference.
Two years ago, the glaciologists Robert DeConto and David Pollard rocked their field with a paper arguing that several massive glaciers in Antarctica were much more unstable than previously thought. Those key glaciers—which include Thwaites Glacier and Pine Island Glacier, both in the frigid continent’s west—could increase global sea levels by more than three feet by 2100, the paper warned. Such a rise could destroy the homes of more than 150 million people worldwide.
[…]
It is a reassuring constraint placed on one of the most alarming scientific hypotheses advanced this decade. The press had described DeConto and Pollard’s original work as an “ice apocalypse” spawned by a “doomsday glacier.” Now their worst-case skyrocketing sea-level scenario seems extremely unlikely, at least within our own lifetimes.
[…]
Yet their work—and the work of other sea-level-rise scientists—still warns of potential catastrophe for our children and grandchildren. If every country meets its current commitment under the Paris Agreement, the Earth will warm about 2.7 degrees Celsius by the end of the century compared with its pre-industrial average. In their new research, DeConto and his colleagues say that there’s a tipping point, somewhere between 2 and 3 degrees Celsius of temperature rise, after which the West Antarctic Ice Sheet will slip into rapid and shattering collapse.
[…]
The new results inform one of the biggest outstanding questions—and most fervent debates—concerning how climate change will reshape our world: How much will the seas rise, and how fast will that upheaval occur? DeConto and several other American glaciologists—including Richard Alley, a professor at Penn State and a co-author of the new research—represent something like the vanguard of that discussion. They champion an idea called “marine ice-cliff instability,” or MICI, which maintains that West Antarctic glaciers will eventually crumble under their own weight. By the middle of next century, they warn, this mechanism could send ocean levels soaring at a rate of several feet per decade. For reference: Along the U.S. East Coast, the Atlantic Ocean has risen by only about a foot over the last 12 decades.
While “marine ice-cliff instability” might be clunky, the idea is cinematic.
[…]
Other researchers find this possible future somewhat fantastic. “We, as European modelers, are slightly more skeptical of the marine-cliff idea,” Frank Pattyn, a glaciologist at the Free University of Brussels, told me. “It has not been observed, not at such a scale.”
[…]
There is only one place in the world where MICI is definitely happening: Jakobshavn Glacier, on the west coast of Greenland.
[…]
Alley, the Penn State glaciologist, addressed the sapphire-colored elephant in the room immediately after taking the dais. As he sees it, it’s just common sense that Antarctic glaciers will develop problematic ice cliffs.
[…]
In this scenario, he warned, “We will not have analogues … We are going to move outside the instrumental data that we use to calibrate our models.”
Then came the skeptics. Dan Martin, a computational scientist at Lawrence Berkeley National Lab, argued that his and his colleagues’ work showed that ice cliffs might simply be a product of running a computer model of ice physics at a too-low resolution. Eric Larour, a physicist at NASA, presented the possibility that the physics of the Earth itself might slightly counteract some rapid ice-cliff collapse. As the ice sitting on West Antarctica melts, the bedrock below it will bounce back up.
“When ice melts or thins, you can think that the Earth [below it] is going to rebound,” he said. That bedrock will rise, lifting the glacier partly out of the water. Such a mechanism could buy humanity some time, he said, giving us a “23 to 30 year delay” in the total collapse of West Antarctica. This effect might hold off the collapse of West Antarctica until 2250 or 2300, but then the ice sheet would disintegrate as fast as ever.
The meeting arrived at no clear conclusion.
[…]
MICI remains a young idea, first proposed only six years ago. It need not be rejected simply because scientists haven’t arrived at hard conclusions yet, Fricker, the Scripps glaciologist, said.
[…]
“It might not happen,” Fricker said. “But if there’s a chance that it could happen, then shouldn’t you involve that in your planning? If you’re hosting a picnic and it might rain, you don’t necessarily move the whole event, but you probably do make a Plan B. If you’re planning a city … you might as well keep this in the back of your mind.”
We want to hear what you think about this article. Submit a letter to the editor or write to letters@theatlantic.com.
I thought about submitting a letter… But I doubt they would want to hear what I think about this article. Robinson Meyer is a twenty-something year old staff writer for The Atlantic with a 2013 B.A. in music.
I love this bit: “Then came the skeptics.” Why were they even invited? I thought they had all been banished from the AGU. How dare they throw cold water on a perfectly good model-derived catastrophe… /Sarc.
Marine ice cliff instability (MICI) “has not been observed, not at such a scale,” “might simply be a product of running a computer model of ice physics at a too-low resolution,” ignores post glacial rebound, couldn’t occur before ” until 2250 or 2300″… Yet “the idea is cinematic,” “it’s just common sense that Antarctic glaciers will develop problematic ice cliffs” and something we should plan for…
Figure 1. AEUHHH????
How can you plan for something that’s never been observed? May not ever happen? Won’t happen for 200-300 years, if it does happen? What’s the point in even keeping “this in the back of your mind.” No one with this in the back of their mind today will be alive in 2250. Their children won’t be alive. Their grandchildren probably won’t be alive. In 2250, we can just let Star Fleet take care of this.
This comment was most reassuring…
“We will not have analogues … We are going to move outside the instrumental data that we use to calibrate our models.”
–Richard B. Alley, Penn State University
That will certainly be a relief to climate modelers, Their models will no longer have to be constrained by reality… Which won’t be much of a change. RCP8.5 is already unconstrained by reality.
Speaking of RCP8.5 and DeConto & Pollard, that’s how all of this got started…
Polar temperatures over the last several million years have, at times, been slightly warmer than today, yet global mean sea level has been 6–9 metres higher as recently as the Last Interglacial (130,000 to 115,000 years ago) and possibly higher during the Pliocene epoch (about three million years ago). In both cases the Antarctic ice sheet has been implicated as the primary contributor, hinting at its future vulnerability. Here we use a model coupling ice sheet and climate dynamics— including previously underappreciated processes linking atmospheric warming with hydrofracturing of buttressing ice shelves and structural collapse of marine-terminating ice cliffs—that is calibrated against Pliocene and Last Interglacial sea-level estimates and applied to future greenhouse gas emission scenarios. Antarctica has the potential to contribute more than a metre of sea-level rise by 2100 and more than 15 metres by 2500, if emissions continue unabated. In this case atmospheric warming will soon become the dominant driver of ice loss, but prolonged ocean warming will delay its recovery for thousands of years.
The “more than a metre of sea-level rise by 2100 and more than 15 metres by 2500″ is based on bad science fiction (RCP8.5)…
Figure 2. Figure 5 from DeConto & Pollard, 2016. “Large Ensemble model analyses of future Antarctic contributions to GMSL. a, RCP ensembles to 2500. b, RCP ensembles to 2100. Changes in GMSL are shown relative to 2000, although the simulations begin in 1950. Ensemble members use combinations of model parameters (Methods) filtered according to their ability to satisfy two geologic criteria: a Pliocene target of 10–20 m GMSL and a LIG target of 3.6–7.4 m. c and d are the same as a and b, but use a lower Pliocene GMSL target of 5–15 m. Solid lines are ensemble means, and the shaded areas show the standard deviation (1σ) of the ensemble members. The 1σ ranges represent the model’s parametric uncertainty, while the alternate Pliocene targets (a and b versus c and d) illustrate the uncertainty related to poorly constrained Pliocene sea-level targets. Mean values and 1σ uncertainties at 2500 and 2100 are shown.”
DeConto & Pollard essentially asserted that we are headed back to the Pliocene over the next few hundred years.
Not likely.
Figure 3. High Latitude SST (°C) From Benthic Foram δ18O (Zachos, et al., 2001) and HadSST3 ( Hadley Centre / UEA CRU via www.woodfortrees.org) plotted at same scale, tied in at 1950 AD.
We’ve already experienced nearly 1 ºC of warming since pre-industrial time. Another 0.5 to 1.0 ºC between now and the end of the century doesn’t even put us into Eemian climate territory, much less the Pliocene. Beyond that, who knows what will happen? While fossil fuels will dominate the energy mix for much of this century, does anyone really believe that better source of energy won’t be added to the mix between 2100 and 2250?
There is only one place in the world where MICI is definitely happening: Jakobshavn Glacier, on the west coast of Greenland.
Jakobshavn Glacier is not an MICI analogy for Antarctica. It’s not even an analogy for any other glaciers in Greenland.
Jakobshavn Glacier Calving Front Recession from 1850 to 2006
Visualizations by Cindy Starr Released on January 5, 2007
Jakobshavn Isbrae is located on the west coast of Greenland at Latitude 69 N. The ice front, where the glacier calves into the sea, receded more than 40 km between 1850 and 2006. Between 1850 and 1964 the ice front retreated at a steady rate of about 0.3 km/yr, after which it occupied approximately the same location until 2001, when the ice front began to recede again, but far more rapidly at about 3 km/yr. After 2004, the glacier began retreating up its two main tributaries: one to the north, and a more rapid one to the southeast.
These changes are important for many reasons. As more ice moves from glaciers on land into the ocean, it causes a rise in sea level. Jakobshavn Isbrae is Greenland’s largest outlet glacier, draining 6.5 percent of Greenland’s ice sheet area. The ice stream’s speed-up and near-doubling of the ice flow from land into the ocean has increased the rate of sea level rise by about .06 millimeters (about .002 inches) per year, or roughly 4 percent of the 20th century rate of sea level increase.
This image of the Jakobshavn glacier on 07/07/2001 shows the changes in the glacier’s calving front between 1851 and 2006. Historic calving front locations, 1851 through 1964, were compiled by Anker Weidick and Ole Bennike and are shown here in gray. Recent calving front locations, 2001 through 2006, derived from satellite imagery are show in colors. A distance scale is provided.
The calving lines were overlaid on a 2001 Landsat image.
This article was updated in July 2007 with a new image…
Figure 4. “The recession of calving front locations is shown over an image of the Jakobshavn glacier on 08/06/2006. Historic calving front locations from 1851 through 1964, compiled by Anker Weidick and Ole Bennike, are shown here in gray. Recent calving front locations, 2001 through 2006, derived from satellite imagery are show in colors.”
The glacier had indeed retreated from 2001-2006 after nearly 40 years of little movement. However, all of the retreat has occurred on the “floating ice tongue”…
Figure 5. “The calving front line from 07/07/2001 deliniates the area of floating icebergs from the solid glacial ice. Semi-transparent overlays identify the portion of the glacier which is over water (blue) and over land (tan).”
Jakobshavn Isbrae – Greenland Glacier Has Always Changed With The Climate
By News Staff | July 16th 2011
New research on Jakobshavn Isbrae, a tongue of ice extending out to sea from Greenland’s west coast, shows that large, marine-calving glaciers don’t just shrink rapidly in response to global warming, they also grow at a remarkable pace during periods of global cooling. *Glaciers change.
[…]
Jakobshavn Isbrae has been the focus of intense scientific interest because it is one of the world’s fastest-flowing glaciers, releasing enormous quantities of Greenland’s ice into the ocean. It is believed that changes in the rate at which icebergs calve off from the glacier could influence global sea level rise. The decline of Jakobshavn Isbrae between 1850 and 2010 has been documented, mostly recently through aerial photographs and satellite photographs.
“We know that Jakobshavn Isbrae has retreated at this incredible rate in recent years, and our study suggests that it advanced that fast, also,” said Jason Briner, the associate professor of geology at the University of Buffalo, who led the research. “Our results support growing evidence that calving glaciers are particularly sensitive to climate change.”
Figure 6. Jakobshavn Isbrae. (Wikipedia and Google Earth)
“Our results support growing evidence that calving glaciers are particularly sensitive to climate change.” Greenland’s climate is always changing… Always has and always will change… And the climate changes observed over the last few decades are not unprecedented. The Greenland ice sheet is no more disappearing this year than it was last year and it is physically impossible for the ice sheet to “collapse” into the ocean.
Each and every [fill-in-the-blank]-sized iceberg to calve off Greenland or Antarctica triggers the same alarmist nonsense and glacial junk science journalism. Glaciers are rivers of ice. They flow downhill. Downhill is generally toward the ocean, where they calve icebergs. Increased calving of icebergs is indicative of excess ice accumulation, not melting. Past glacial stages and stadials are associated with an increase in dropstones in marine sediment cores because icebergs calve more frequently when the source of ice is expanding.
From 1850 through 2006, Jakobshavn Isbrae’s floating ice tongue has calved into the ocean. Prior to 1850, glaciers had mostly been advancing since the end of the Holocene Climatic Optimum, a period known as “Neoglaciation.” While the retreat of Jakobshavn Isbrae’s floating ice tongue was punctuated with a prolonged hiatus associated with the mid-20th century cooling period, this process began at the end of Neoglaciation. The end of Neoglaciation was a “good thing”…
Figure 7. The Ice Age Cometh? Science News, March 1, 1975. Had Neoglaciation not ended, the “Ice Age” might just have “cometh,”
References
DeConto, Robert & Pollard, David. (2016). Contribution of Antarctica to past and future sea-level rise. Nature. 531. 591-597. 10.1038/nature17145.
Zachos, J. C., Pagani, M., Sloan, L. C., Thomas, E. & Billups, K. Trends, rhythms, and aberrations in global climate 65 Ma to present. Science 292, 686–-693 (2001).
… and long before that its luminosity will increase enough to sterilize planet Earth of all life above ground and vaporize the oceans.
u.k.(us)
January 5, 2019 3:58 pm
Terrifying, is when the favorite is closing in on your horse, you’re at 20-1 and the horse is begging for the wire,
the jockey is trying to lose weight and become one with the horse’s momentum….
Tom Abbott
January 5, 2019 3:59 pm
From the article: “If every country meets its current commitment under the Paris Agreement, the Earth will warm about 2.7 degrees Celsius by the end of the century compared with its pre-industrial average.”
Pure speculation. This is what passes for climate science.
The fact is they have no idea if the Earth will warm that much or even at all by the end of the century. Yet they make these declarations as if they are rock-solid.
Alarmist climate science is just one unsubstantiated claim after another. It’s infuriating.
To make it true, they will place the beginning of the industrial age at the coldest point of the Maunder Minimum, and annually adjust that temperature until it is 2.7 degrees colder than 2100. “He who controls the present controls the past; he who controls the pas controls the future.” Is one of the 3 main slogans of the party Ingsoc (Labour/Tories).
Robert Osborn
January 5, 2019 5:25 pm
Cinematic, yep! All they need is a good cast and a good script. Perfect for Al Gore as producer.
EVIDENCE OF STABILITY OF THE WEST ANTARCTIC ICE SHEET
In May, 2015, a New York Times headline stated “Scientists Warn of Rising Oceans from Polar Melt” and goes on to say: “A large section of the mighty West Antarctica ice sheet has begun falling apart and its continued melting now appears to be unstoppable” and “the melting could destabilize neighboring parts of the ice sheet and a rise in sea level of 10 feet or more may be unavoidable in coming centuries.” Virtually every newspaper and TV news show went ballistic with dire predictions of the “unstoppable” catastrophe about to unfold. Two papers on the Pine Island and Thwaites glaciers in West Antarctica triggered this renewed outburst of catastrophic predictions. AWashington Post headline stated “Research casts alarming light on decline of West Antarctic Glaciers” and goes on to say that “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” and “the region’s mile-thick ice sheet could collapse and raise sea levels as much as 11 feet.The consequences of such an amount of sea-level rise for the United Stateseor for any other coastal regiondare staggering to contemplate.12.8 million Americans live on land less than 10 feet above their local high-tide line.$2.4 trillion worth of property is occupying this land, excluding Hawaii and Alaska.The cities that would be most affected include Miami, New Orleans, and New York.Within 100e200 years, one-third of West Antarctica could be gone.The effects of climate change are outpacing scientific predictions, driven in part, scientists say, by soaring levels of greenhouse gases in the atmosphere.” In apaper titled “Widespread,Rapid Grounding Line Retreat ofPine Island, Thwaites, Smith, and Kohlerglaciers, West Antarctica from 1992 to 2011,” Rignot et al. (2014) contend that increased flow velocity of several small outlet glaciers of the West Antarctic Ice Sheet as a result of increased rates of calving into the sea will lead to “unstoppable collapse” of the entire West Antarctic Ice Sheet and raising of sea level by 4 ft, which will displace tens of millions of people from coastal areas around the world. According to Rigot, an electrical engineer, “Warm ocean currents and geographic peculiarities have helped kick offachain reaction at the AmundsenSea-areaglaciers, melting them faster than previously realized and pushing them ‘past the point of no return’.The system [becomes] a chain reaction that is unstoppable, [with] every process of retreat feeding the next one.The glacial retreat there appears unstoppable.” Curiously, Rignot asserts that “heat makes the grounding line retreat inland, leaving a less massive ice shelf above. When ice shelves lose mass, they can’t hold back inland glaciers from flowing toward the sea.” Apparently he believes that the terminal area of the glacier acts like a dam, “holding back” the rest of the glacier, and if it is removed, the glacier will essentially slide into the sea. That’s a false premisedevery glaciologist knows that where a glacier terminates is determined by its mass balance between the amount of accumulation of new ice every year and the amount of ice loss by melting or calving. Thus, an important factor for the Rignot “unstoppable collapse” of the West Antarctic Ice Sheet is based on a false premise. In a paper titled “Marine Ice Sheet Collapse Potentially Underway for the Thwaites Glacier Basin, West Antarctica,” Joughin et al. (2014) also infer that the entire West Antarctic Ice Sheet will soon disappear, resulting in a sea level rise of up to 10 ft. The authors contend that recent retreat of the Pine Island and Thwaites glaciers has occurred because warm ocean water has caused melting of ice on the underside of the glaciers, causing them to thin and calve more rapidly. Because the base of most of the West Antarctic Ice Sheet lies below sea level, the authors contend that ocean water will melt its way up several small embayments under the ice sheet, which is more than 1000 miles across, and cause it to collapse abruptly. They refer to this as “unstoppable” because the glacier base is below sea level and they claim that there is nowhere that the glacier can ground, resulting in total collapse of the ice sheet into the sea. To get a perspective of what is happening now and what might or might not happen in the future requires a look at the overall geologic setting and the scale of the size and thickness of the West Antarctic Ice Sheet relative to the Pine Island and Thwaites outlet glaciers. The West Antarctic Ice Sheet makes up only about 8½ % of Antarctic ice, and the Pine Island glacier makes up about 10% of the West Antarctic Ice Sheet. Most of the West Antarctic Ice Sheet lies SE of the Pine Island glacier and at its SW margin is about 1000 miles from the Pine Island and Thwaites outlet glaciers. Ice in the SE region flows into the Ross Sea, making the Ross Ice Shelf, and has little if anything to do with the part of the ice sheet that flows through the Pine Island and Thwaites outlet glaciers far to the north beyond the ice divide. The Pine Island and Thwaites glaciers are not independent glaciersdthey are ice streams from the NW part of the West Antarctic Ice Sheet flowing through narrow embayments bounded by mountains. Their termini calve into the Amundsen Sea, but the rest of the ice sheet is grounded and all of the southwestern part discharges into the Ross Sea. The entire western and southern margins of the West Antarctic Ice Sheet are separated from the ocean by mountains, so these are virtually the only outlets for the ice. The total width of the Pine Island and Thwaites outlet glaciers makes up only about 60 miles of the 2500 miles of coastline along the western and southern margins of the
IV. POLAR ICE
8. EVIDENCE OF STABILITY OF THE WEST ANTARCTIC ICE SHEET 131
ice sheet. The major ice discharge from the SW margin into the Ross Ice Shelf is not affected by what goes on in the northern part of the ice sheet. Scale is importantdonly when looking a map of the size of the West Antarctic Ice Sheet does it become apparent just how tiny the Pine Island and Thwaites outlet glaciers are relative to the size of the West Antarctic Ice Sheet (Figs. 7.13 and 7.16). The rate of glacial retreat is estimated at 10e23 ft per year. The West Antarctic Ice Sheet is roughly 800e1000 miles across, depending on where you measure it. So melting at 10 ft per year would take 528,000 years and at 23 ft per year would take 229,565 years.
9. CREDIBILITY OF THE “UNSTOPPABLE COLLAPSE OF THE WEST ANTARCTIC ICE SHEET”
The base of most of the West Antarctic Ice Sheet lies below sea level (Figs. 7.17 and 7.18) and it is because of this that the West Antarctic Ice Sheet is predicted to collapse. The deepest parts of the subglacial basin are mostly about 10,000 ft (3300 m) deep and lie beneath the central portion of the ice sheet where the ice is the thickest (Fig. 7.19). More important than just depth below sea level is how thick the ice is relative to the depth below sea level. If the ice is thicker than the depth of its base below sea level, the ice will not float.
9.1 Thickness of the West Antarctic Ice Sheet
Fig. 7.19 shows the thickness of the West Antarctic Ice Sheet. Most of the ice sheet is more than 6000 ft (2000 m) thick and in places, reaches up to 10,000 ft (3000 m) thick. The importance of ice thickness is that virtually all of the ice sheet is considerably thicker than the depth below sea level to bedrock, so the ice is grounded and will not float. Also important is the source area of the outlet glaciers. Fig. 7.20 shows ice divides and ice drainage areas. The Pine Island outlet glacier drains only a relative small portion of the West Antarctic Ice Sheet, so it is difficult to see how events there could result in collapse of the entire Antarctic Ice Sheet.
FIGURE 7.16 Pine Island outlet glacier and the northwestern part of the West Antarctic Ice Sheet.
FIGURE 7.17 Subglacial topography of the West Antarctic Ice Sheet.
IV. POLAR ICE
7. EVIDENCE THAT ANTARCTICA IS COOLING, NOT WARMING132
The authors assert that “we find no major bed obstacle that would prevent the glaciers from further retreat and draw down of the entire basin.” But that is contrary to what is shown in Fig. 7.21, which is a profile of the West Antarctic Ice Sheet from the east coast to the Transantarctic Mountains, showing thickness of the ice sheet, sea level, and the subglacial floor. At its deepest part, the subglacial floor is 2000 m (6500 ft) below sea level, but almost all of the subglacial floor in this profile is less than 1000 m (3300 ft) below sea level. The ice is mostly more than 2500 m (8000 ft) thick, so basic physics tells us it will not float in 1000 m (3300 ft) of water nor will sea water melt its way under the ice. At 200 km (125 miles) up-ice from the terminus, the ice sheet is about 1600 m (5200 ft) thick and the subglacial floor is above sea level. At 300 km from the terminus, the subglacial floor is 1000 m (3300 ft) above sea level. About 700 km from the terminus, the ice is about 1700 m (5500 ft) thick and the subglacial floor is near sea level. About 1050 to 1150 km (650e700 miles) from the terminus, bedrock occurs at sea level. Because the depth of the subglacial floor below sea level is substantially less than the thickness of ice, it will not float and collapse!
Such physical facts do not deter alarmist rhetoric to the uneducated masses. The climate Alarmists depend on stupified Arts majors journalists to spew their propaganda fact-free.
The history of deglaciation of the West Antarctic Ice Sheet (WAIS) gives clues about its future. Southward grounding-line migration was dated past three locations in the Ross Sea Embayment. Results indicate that most recession occurred during the middle to late Holocene in the absence of substantial sea level or climate forcing. Current grounding-line retreat may reflect ongoing ice recession that has been under way since the early Holocene. If so, the WAIS could continue to retreat even in the absence of further external forcing…
H. Conway et al, 1999. Past and Future Grounding-Line Retreat of the West Antarctic Ice Sheet. Science 8 October 1999: Vol. 286 no. 5438 pp. 280-283
The collapse (retreat of the grounding line) began about 20,000 years ago. It is irreversible because “the WAIS could continue to retreat even in the absence of further external forcing” and there are no topographic obstacles to prevent it from flowing downhill into the ocean.
Baiscally, the “collapse” has been ‘irreversible” since the last glacial maximum and will remain “irreversible” until the onset of the next glacial stage.
“Our findings overturn the assumption of progressive retreat of the grounding line during the Holocene in West Antarctica, and corroborate previous suggestions of ice-sheet re-advance”
Yes, I saw that paper. It is quite interesting. It is difficult to explain the presence of detectable quantities of radiocarbon under the WAIS without a readvance of the grounding line.
A I’ve pointed out before it is most unfortunate that the WAIS Divide ice coring project deliberately avoided drilling all the way to bedrock.
“If the ice is thicker than the depth of its base below sea level, the ice will not float.”
Actually “If the ice is thicker than 113% of the the depth of its base below sea level, the ice will not float.” Salt water is appreciably denser than glacier ice.
‘And where are those figures you refer to? Not in Joughin et al. or Rignot et al.
noaaprogrammer
January 5, 2019 7:54 pm
If these climastrologists want to gorge themselves on catastrophes, just go to the Book of Revelation: the sun scorches people with intense heat; the sea turns to blood, hailstones that weigh a hundred pounds, etc., etc.
Johann Wundersamer
January 6, 2019 3:34 am
“MICI, which maintains that West Antarctic glaciers will eventually crumble under their own weight.”
No. Miezi or Miauzi is the pet name for cats.
Kyle in Upstate NY
January 6, 2019 3:37 am
What’s absolutely amazing and astounding is that these idiots actually think they can accurately predict what might happen in hundreds of years, AND how it supposedly would affect humans because apparently they think they can predict a couple of hundred years worth of technological and economic development before it has happened. The next one hundred years alone is going to see far more scientific and technological development than the last one hundred, given how fast such development happens now, and the last one-hundred saw quite a bit. The next one hundred years after that…!?
eternaloptimist
January 6, 2019 5:22 am
For those of you that are truly concerned about your descendants in 300 years,
put 100 bucks into the bank.
if you can get 7% it will be worth $92,089,449,276
“It might not happen,” Fricker said. “But if there’s a chance that it could happen, then shouldn’t you involve that in your planning? If you’re hosting a picnic and it might rain, you don’t necessarily move the whole event, but you probably do make a Plan B.”
Here we go again with the “could”. Note the clever misdirection: “Could”, to a scientist, means that it is not logically impossible. That includes a whole pile of absurdly unlikely events.
But “might”, to a picnic-goer, means some reasonable chance of rain: maybe 10%, maybe 50%, depending on how much you want your picnic dry. It doesn’t mean 0.0001%, which is definitely included in a scientist’s “could”.
Now, the next question to ask is were those coding errors accidental or deliberate.
And the question after that is should we be spending trillions of extra dollars fighting CO2 before we even know the quality of the computer models that claim CO2 is detrimental and huge sums need to be spent to mitigate the problem?
Hocus Locus
January 6, 2019 5:34 pm
How can you plan for something that’s never been observed?
In 10B years the sun will burn out. Its just something to keep in the back of your mind.
Before it does that, it will envelope the Earth.
… and long before that its luminosity will increase enough to sterilize planet Earth of all life above ground and vaporize the oceans.
Terrifying, is when the favorite is closing in on your horse, you’re at 20-1 and the horse is begging for the wire,
the jockey is trying to lose weight and become one with the horse’s momentum….
From the article: “If every country meets its current commitment under the Paris Agreement, the Earth will warm about 2.7 degrees Celsius by the end of the century compared with its pre-industrial average.”
Pure speculation. This is what passes for climate science.
The fact is they have no idea if the Earth will warm that much or even at all by the end of the century. Yet they make these declarations as if they are rock-solid.
Alarmist climate science is just one unsubstantiated claim after another. It’s infuriating.
Their use of a decimal point shows they have a sense of humor.
Only when they are predicting doom.
When doom fails to materialize, they are most dour, and thoroughly unamused.
To make it true, they will place the beginning of the industrial age at the coldest point of the Maunder Minimum, and annually adjust that temperature until it is 2.7 degrees colder than 2100. “He who controls the present controls the past; he who controls the pas controls the future.” Is one of the 3 main slogans of the party Ingsoc (Labour/Tories).
Cinematic, yep! All they need is a good cast and a good script. Perfect for Al Gore as producer.
Wait a second, we were already told years ago that the WAIS is collapsing and there is nothing that can stop it.
EVIDENCE OF STABILITY OF THE WEST ANTARCTIC ICE SHEET
In May, 2015, a New York Times headline stated “Scientists Warn of Rising Oceans from Polar Melt” and goes on to say: “A large section of the mighty West Antarctica ice sheet has begun falling apart and its continued melting now appears to be unstoppable” and “the melting could destabilize neighboring parts of the ice sheet and a rise in sea level of 10 feet or more may be unavoidable in coming centuries.” Virtually every newspaper and TV news show went ballistic with dire predictions of the “unstoppable” catastrophe about to unfold. Two papers on the Pine Island and Thwaites glaciers in West Antarctica triggered this renewed outburst of catastrophic predictions. AWashington Post headline stated “Research casts alarming light on decline of West Antarctic Glaciers” and goes on to say that “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” and “the region’s mile-thick ice sheet could collapse and raise sea levels as much as 11 feet.The consequences of such an amount of sea-level rise for the United Stateseor for any other coastal regiondare staggering to contemplate.12.8 million Americans live on land less than 10 feet above their local high-tide line.$2.4 trillion worth of property is occupying this land, excluding Hawaii and Alaska.The cities that would be most affected include Miami, New Orleans, and New York.Within 100e200 years, one-third of West Antarctica could be gone.The effects of climate change are outpacing scientific predictions, driven in part, scientists say, by soaring levels of greenhouse gases in the atmosphere.” In apaper titled “Widespread,Rapid Grounding Line Retreat ofPine Island, Thwaites, Smith, and Kohlerglaciers, West Antarctica from 1992 to 2011,” Rignot et al. (2014) contend that increased flow velocity of several small outlet glaciers of the West Antarctic Ice Sheet as a result of increased rates of calving into the sea will lead to “unstoppable collapse” of the entire West Antarctic Ice Sheet and raising of sea level by 4 ft, which will displace tens of millions of people from coastal areas around the world. According to Rigot, an electrical engineer, “Warm ocean currents and geographic peculiarities have helped kick offachain reaction at the AmundsenSea-areaglaciers, melting them faster than previously realized and pushing them ‘past the point of no return’.The system [becomes] a chain reaction that is unstoppable, [with] every process of retreat feeding the next one.The glacial retreat there appears unstoppable.” Curiously, Rignot asserts that “heat makes the grounding line retreat inland, leaving a less massive ice shelf above. When ice shelves lose mass, they can’t hold back inland glaciers from flowing toward the sea.” Apparently he believes that the terminal area of the glacier acts like a dam, “holding back” the rest of the glacier, and if it is removed, the glacier will essentially slide into the sea. That’s a false premisedevery glaciologist knows that where a glacier terminates is determined by its mass balance between the amount of accumulation of new ice every year and the amount of ice loss by melting or calving. Thus, an important factor for the Rignot “unstoppable collapse” of the West Antarctic Ice Sheet is based on a false premise. In a paper titled “Marine Ice Sheet Collapse Potentially Underway for the Thwaites Glacier Basin, West Antarctica,” Joughin et al. (2014) also infer that the entire West Antarctic Ice Sheet will soon disappear, resulting in a sea level rise of up to 10 ft. The authors contend that recent retreat of the Pine Island and Thwaites glaciers has occurred because warm ocean water has caused melting of ice on the underside of the glaciers, causing them to thin and calve more rapidly. Because the base of most of the West Antarctic Ice Sheet lies below sea level, the authors contend that ocean water will melt its way up several small embayments under the ice sheet, which is more than 1000 miles across, and cause it to collapse abruptly. They refer to this as “unstoppable” because the glacier base is below sea level and they claim that there is nowhere that the glacier can ground, resulting in total collapse of the ice sheet into the sea. To get a perspective of what is happening now and what might or might not happen in the future requires a look at the overall geologic setting and the scale of the size and thickness of the West Antarctic Ice Sheet relative to the Pine Island and Thwaites outlet glaciers. The West Antarctic Ice Sheet makes up only about 8½ % of Antarctic ice, and the Pine Island glacier makes up about 10% of the West Antarctic Ice Sheet. Most of the West Antarctic Ice Sheet lies SE of the Pine Island glacier and at its SW margin is about 1000 miles from the Pine Island and Thwaites outlet glaciers. Ice in the SE region flows into the Ross Sea, making the Ross Ice Shelf, and has little if anything to do with the part of the ice sheet that flows through the Pine Island and Thwaites outlet glaciers far to the north beyond the ice divide. The Pine Island and Thwaites glaciers are not independent glaciersdthey are ice streams from the NW part of the West Antarctic Ice Sheet flowing through narrow embayments bounded by mountains. Their termini calve into the Amundsen Sea, but the rest of the ice sheet is grounded and all of the southwestern part discharges into the Ross Sea. The entire western and southern margins of the West Antarctic Ice Sheet are separated from the ocean by mountains, so these are virtually the only outlets for the ice. The total width of the Pine Island and Thwaites outlet glaciers makes up only about 60 miles of the 2500 miles of coastline along the western and southern margins of the
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8. EVIDENCE OF STABILITY OF THE WEST ANTARCTIC ICE SHEET 131
ice sheet. The major ice discharge from the SW margin into the Ross Ice Shelf is not affected by what goes on in the northern part of the ice sheet. Scale is importantdonly when looking a map of the size of the West Antarctic Ice Sheet does it become apparent just how tiny the Pine Island and Thwaites outlet glaciers are relative to the size of the West Antarctic Ice Sheet (Figs. 7.13 and 7.16). The rate of glacial retreat is estimated at 10e23 ft per year. The West Antarctic Ice Sheet is roughly 800e1000 miles across, depending on where you measure it. So melting at 10 ft per year would take 528,000 years and at 23 ft per year would take 229,565 years.
9. CREDIBILITY OF THE “UNSTOPPABLE COLLAPSE OF THE WEST ANTARCTIC ICE SHEET”
The base of most of the West Antarctic Ice Sheet lies below sea level (Figs. 7.17 and 7.18) and it is because of this that the West Antarctic Ice Sheet is predicted to collapse. The deepest parts of the subglacial basin are mostly about 10,000 ft (3300 m) deep and lie beneath the central portion of the ice sheet where the ice is the thickest (Fig. 7.19). More important than just depth below sea level is how thick the ice is relative to the depth below sea level. If the ice is thicker than the depth of its base below sea level, the ice will not float.
9.1 Thickness of the West Antarctic Ice Sheet
Fig. 7.19 shows the thickness of the West Antarctic Ice Sheet. Most of the ice sheet is more than 6000 ft (2000 m) thick and in places, reaches up to 10,000 ft (3000 m) thick. The importance of ice thickness is that virtually all of the ice sheet is considerably thicker than the depth below sea level to bedrock, so the ice is grounded and will not float. Also important is the source area of the outlet glaciers. Fig. 7.20 shows ice divides and ice drainage areas. The Pine Island outlet glacier drains only a relative small portion of the West Antarctic Ice Sheet, so it is difficult to see how events there could result in collapse of the entire Antarctic Ice Sheet.
FIGURE 7.16 Pine Island outlet glacier and the northwestern part of the West Antarctic Ice Sheet.
FIGURE 7.17 Subglacial topography of the West Antarctic Ice Sheet.
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7. EVIDENCE THAT ANTARCTICA IS COOLING, NOT WARMING132
The authors assert that “we find no major bed obstacle that would prevent the glaciers from further retreat and draw down of the entire basin.” But that is contrary to what is shown in Fig. 7.21, which is a profile of the West Antarctic Ice Sheet from the east coast to the Transantarctic Mountains, showing thickness of the ice sheet, sea level, and the subglacial floor. At its deepest part, the subglacial floor is 2000 m (6500 ft) below sea level, but almost all of the subglacial floor in this profile is less than 1000 m (3300 ft) below sea level. The ice is mostly more than 2500 m (8000 ft) thick, so basic physics tells us it will not float in 1000 m (3300 ft) of water nor will sea water melt its way under the ice. At 200 km (125 miles) up-ice from the terminus, the ice sheet is about 1600 m (5200 ft) thick and the subglacial floor is above sea level. At 300 km from the terminus, the subglacial floor is 1000 m (3300 ft) above sea level. About 700 km from the terminus, the ice is about 1700 m (5500 ft) thick and the subglacial floor is near sea level. About 1050 to 1150 km (650e700 miles) from the terminus, bedrock occurs at sea level. Because the depth of the subglacial floor below sea level is substantially less than the thickness of ice, it will not float and collapse!
Such physical facts do not deter alarmist rhetoric to the uneducated masses. The climate Alarmists depend on stupified Arts majors journalists to spew their propaganda fact-free.
Here’s a good one…
H. Conway et al, 1999. Past and Future Grounding-Line Retreat of the West Antarctic Ice Sheet. Science 8 October 1999: Vol. 286 no. 5438 pp. 280-283
The collapse (retreat of the grounding line) began about 20,000 years ago. It is irreversible because “the WAIS could continue to retreat even in the absence of further external forcing” and there are no topographic obstacles to prevent it from flowing downhill into the ocean.
Baiscally, the “collapse” has been ‘irreversible” since the last glacial maximum and will remain “irreversible” until the onset of the next glacial stage.
Another one.
“Our findings overturn the assumption of progressive retreat of the grounding line during the Holocene in West Antarctica, and corroborate previous suggestions of ice-sheet re-advance”
https://www.ncbi.nlm.nih.gov/pubmed/29899456
Cherry picked, to continue the fun.
Yes, I saw that paper. It is quite interesting. It is difficult to explain the presence of detectable quantities of radiocarbon under the WAIS without a readvance of the grounding line.
A I’ve pointed out before it is most unfortunate that the WAIS Divide ice coring project deliberately avoided drilling all the way to bedrock.
They also wound up with much lower resolution ice cores than they expected.
“If the ice is thicker than the depth of its base below sea level, the ice will not float.”
Actually “If the ice is thicker than 113% of the the depth of its base below sea level, the ice will not float.” Salt water is appreciably denser than glacier ice.
‘And where are those figures you refer to? Not in Joughin et al. or Rignot et al.
If these climastrologists want to gorge themselves on catastrophes, just go to the Book of Revelation: the sun scorches people with intense heat; the sea turns to blood, hailstones that weigh a hundred pounds, etc., etc.
“MICI, which maintains that West Antarctic glaciers will eventually crumble under their own weight.”
No. Miezi or Miauzi is the pet name for cats.
What’s absolutely amazing and astounding is that these idiots actually think they can accurately predict what might happen in hundreds of years, AND how it supposedly would affect humans because apparently they think they can predict a couple of hundred years worth of technological and economic development before it has happened. The next one hundred years alone is going to see far more scientific and technological development than the last one hundred, given how fast such development happens now, and the last one-hundred saw quite a bit. The next one hundred years after that…!?
For those of you that are truly concerned about your descendants in 300 years,
put 100 bucks into the bank.
if you can get 7% it will be worth $92,089,449,276
“It might not happen,” Fricker said. “But if there’s a chance that it could happen, then shouldn’t you involve that in your planning? If you’re hosting a picnic and it might rain, you don’t necessarily move the whole event, but you probably do make a Plan B.”
Here we go again with the “could”. Note the clever misdirection: “Could”, to a scientist, means that it is not logically impossible. That includes a whole pile of absurdly unlikely events.
But “might”, to a picnic-goer, means some reasonable chance of rain: maybe 10%, maybe 50%, depending on how much you want your picnic dry. It doesn’t mean 0.0001%, which is definitely included in a scientist’s “could”.
Take a look at this:
https://principia-scientific.org/nasa-whistleblower-exposes-huge-climate-model-gaffes/
and you’ll see why the “models” are a joke. This one is the first to admit it:
“We will not have analogues … We are going to move outside the instrumental data that we use to calibrate our models.”
Thanks for the link, Yooper.
Now, the next question to ask is were those coding errors accidental or deliberate.
And the question after that is should we be spending trillions of extra dollars fighting CO2 before we even know the quality of the computer models that claim CO2 is detrimental and huge sums need to be spent to mitigate the problem?
https://slate.com/business/2019/01/chicagos-deep-tunnel-is-it-the-solution-to-urban-flooding-or-a-cautionary-tale.html
[…] Harvey was a once-in-10,000-year storm […]
MICI…marine ice cliff instability ?
All cliffs are unstable whether constructed from marine ice or otherwise.
It’s the nature of cliffs