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Author Topic: Ice Apocalypse - MULTIPLE METERS SEA LEVEL RISE (narrated video)  (Read 19895 times)

RoxTheGeologist

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Re: Ice Apocalypse - MULTIPLE METERS SEA LEVEL RISE (narrated video)
« Reply #200 on: October 26, 2018, 06:00:41 PM »
As continued global warming should increase the frequency with which atmospheric rivers reach Greenland, we may be in for some rude surprises in the coming decades (w.r.t. increasing rates of ice mass loss from the Greenland Ice Sheet):

William Neff (2018), "Atmospheric rivers melt Greenland", Nature Climate Change 8, 857-858, DOI: https://doi.org/10.1038/s41558-018-0297-4

http://www.nature.com/articles/s41558-018-0297-4

Abstract: "Recent years have seen increased melting of the Greenland Ice Sheet, contributing to accelerated rates of sea-level rise.  New research suggests that this melting due to an increased frequency of atmospheric rivers, narrow filaments of moist air moving polewards."

It worries me that we have this huge gravitationally unstable mass of ice on top of Greenland that is gradually warming, getting wet and having more snow piled on top of it, causing more pressure melting at it's base. The only thing keeping it up is the friction along it's base and its mechanical integrity. Once it loses mechanical integrity all bets are off. Whats to stop the whole damn thing sliding into the ocean in chunks?

An underlying principle in geology is that "The present is the key to the past". Unfortunately that doesn't really help us understand events that might happen once every 100,000 years.

Hefaistos

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Re: Ice Apocalypse - MULTIPLE METERS SEA LEVEL RISE (narrated video)
« Reply #201 on: October 27, 2018, 07:28:28 AM »

It worries me that we have this huge gravitationally unstable mass of ice on top of Greenland that is gradually warming, getting wet and having more snow piled on top of it, causing more pressure melting at it's base. The only thing keeping it up is the friction along it's base and its mechanical integrity. Once it loses mechanical integrity all bets are off. Whats to stop the whole damn thing sliding into the ocean in chunks?
...

I don't think it's "gravitationally unstable", especially as compared to parts of Antarctic's ice.
It's got to be a very slow process warming the glaciers up, especially as it seems that Greenland is about to replace the Arctic sea as the north cold pole, once ASI is gone.

Even if there are 'rain rivers' coming in, the quantity of rain water is negligible compared to the thousands of meters of glacier ice.
"Whats to stop the whole damn thing sliding into the ocean in chunks?" - I wouldn't worry about this particular scenario.

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Re: Ice Apocalypse - MULTIPLE METERS SEA LEVEL RISE (narrated video)
« Reply #202 on: October 27, 2018, 08:02:11 AM »
Are you sure about that Hefaistos?
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magnamentis

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Re: Ice Apocalypse - MULTIPLE METERS SEA LEVEL RISE (narrated video)
« Reply #203 on: October 27, 2018, 06:52:00 PM »
just in case that someone's understanding is otherwise, sea ice does NOT add to weight of the region, it will displace the amount of weight in water equivalent. only land-ice would add weight, hence in case that greenland keeps it's approximate ice-volume for another while not much (nothing ) will change and in case greenland would loose a lot of it's ice-shield the balance should improve because a lot of weight (mass) that's not centered by now would disappear while in the centers, south and north there won't be much of a mass-shift.


antarctic ice-shield is sufficiently centered over the pole and the north pole i mentioned above.

only should greenland significantly gain ice volume would things be different while i'm sure, in that case so would other regions and neutralize some (most) of the effect.
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AbruptSLR

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Re: Ice Apocalypse - MULTIPLE METERS SEA LEVEL RISE (narrated video)
« Reply #204 on: October 27, 2018, 11:02:36 PM »
just in case that someone's understanding is otherwise, sea ice does NOT add to weight of the region, it will displace the amount of weight in water equivalent. only land-ice would add weight, hence in case that greenland keeps it's approximate ice-volume for another while not much (nothing ) will change and in case greenland would loose a lot of it's ice-shield the balance should improve because a lot of weight (mass) that's not centered by now would disappear while in the centers, south and north there won't be much of a mass-shift.


antarctic ice-shield is sufficiently centered over the pole and the north pole i mentioned above.

only should greenland significantly gain ice volume would things be different while i'm sure, in that case so would other regions and neutralize some (most) of the effect.

In order to further help avoid confusion, the weight of sea ice is opposed by the opposite force of buoyancy, meaning that it is essentially free floating; however, the great majority of the Greenland Ice Sheet, GIS, consists of marine-terminating glaciers that have a very large component of something called Volume above Floatation.  This means that marine glaciers and marine-terminating glaciers rest on the seafloor, and the weight of the volume above floatation holds these glaciers down from floating.  Thus all portions of the volume above floatation for the GIS (and the EAIS and WAIS) would contribute to sea-level-raise if they were to either melt, and/or move/slide/calve into water depths so deep that they float.

Edit, see also:

Title: "Calculating glacier ice volumes and sea level equivalents"

http://www.antarcticglaciers.org/glaciers-and-climate/estimating-glacier-contribution-to-sea-level-rise/

Extract:

Table 1. Sea level equivalent (SLE) from various land ice sources. From IPCC AR5 (Vaughan et al, 2013).

Ice on land                                   Sea level equivalent (m)
Antarctic Ice Sheet                                           58.3
Greenland Ice Sheet                                         7.36
Glaciers and ice caps                                        0.41
« Last Edit: October 27, 2018, 11:24:02 PM by AbruptSLR »
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Hefaistos

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Re: Ice Apocalypse - MULTIPLE METERS SEA LEVEL RISE (narrated video)
« Reply #205 on: October 30, 2018, 07:06:19 AM »
Are you sure about that Hefaistos?

Yeah. In comparison to e.g. WAIS we shouldn't worry too much about GIS.

GIS rests in a 'cradle' of mountain chains. Sure, there are some weak spots, but with Greenland becoming the new Northern cold pole, I suppose dramatic melt due to 'rain rivers' will be restrained.

+Historical evidence from Eemian:

"Efforts to extract a Greenland ice core with a complete record of the Eemian interglacial (130,000 to 115,000 years ago) have until now been unsuccessful. The response of the Greenland ice sheet to the warmer-than-present climate of the Eemian has thus remained unclear. Here we present the new North Greenland Eemian Ice Drilling (‘NEEM’) ice core and show only a modest ice-sheet response to the strong warming in the early Eemian. We reconstructed the Eemian record from folded ice using globally homogeneous parameters known from dated Greenland and Antarctic ice-core records. On the basis of water stable isotopes, NEEM surface temperatures after the onset of the Eemian (126,000 years ago) peaked at 8 ± 4 degrees Celsius above the mean of the past millennium, followed by a gradual cooling that was probably driven by the decreasing summer insolation. Between 128,000 and 122,000 years ago, the thickness of the northwest Greenland ice sheet decreased by 400 ± 250 metres, reaching surface elevations 122,000 years ago of 130 ± 300 metres lower than the present."

https://www.nature.com/articles/nature11789

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Re: Ice Apocalypse - MULTIPLE METERS SEA LEVEL RISE (narrated video)
« Reply #206 on: October 30, 2018, 07:37:22 AM »
Are you sure about that Hefaistos?

Yeah. In comparison to e.g. WAIS we shouldn't worry too much about GIS.
Of course, because Greenland melt will end up in the the southern hemisphere and Antarctic melt will end up here. As for the rest, I wouldn't be sure or suppose anything with current warming rates.
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AbruptSLR

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Re: Ice Apocalypse - MULTIPLE METERS SEA LEVEL RISE (narrated video)
« Reply #207 on: October 30, 2018, 10:08:58 PM »
It seems to me that the behavior of the NEGIS during the Holocene Optimum ~7.8 – 1.2 ka, provides a point of concern as to how much ice mass loss may occur for this key marine terminating ice stream in the coming decades:

Nicolaj K. Larsen et al. (14 May 2018), "Instability of the Northeast Greenland Ice Stream over the last 45,000 years", Nature Communications, Volume 9, Article number: 1872, doi:10.1038/s41467-018-04312-7

http://www.nature.com/articles/s41467-018-04312-7

Abstract: "The sensitivity of the Northeast Greenland Ice Stream (NEGIS) to prolonged warm periods is largely unknown and geological records documenting such long-term changes are needed to place current observations in perspective. Here we use cosmogenic surface exposure and radiocarbon ages to determine the magnitude of NEGIS margin fluctuations over the last 45 kyr (thousand years). We find that the NEGIS experienced slow early Holocene ice-margin retreat of 30–40 m a−1, likely as a result of the buttressing effect of sea-ice or shelf-ice. The NEGIS was ~20–70 km behind its present ice-extent ~41–26 ka and ~7.8–1.2 ka; both periods of high orbital precession index and/or summer temperatures within the projected warming for the end of this century. We show that the NEGIS was smaller than present for approximately half of the last ~45 kyr and is susceptible to subtle changes in climate, which has implications for future stability of this ice stream."
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litesong

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Re: Ice Apocalypse - MULTIPLE METERS SEA LEVEL RISE (narrated video)
« Reply #208 on: October 31, 2018, 01:03:24 AM »
I don't think it's "gravitationally unstable", especially as compared to parts of Antarctic's ice......  Even if there are 'rain rivers' coming in, the quantity of rain water is negligible compared to the thousands of meters of glacier ice.
First, comparing Greenland to Antarctica can't be done for many reasons, one being that West Antarctica is nearly a set of above sea level islands & underwater grounding rock islands. Second, already the center core of Greenland is in uplift. Third, those 'rain rivers' aren't considered "iffy", since Greenland is losing sea ice, as much as 400+ cubic kilometers per year, even tho total solar irradiation has been low for 12 years. When the Pineapple Express pours on our Cascade Mountains in Washington state, the rain rivers, not only pour into our valleys, but melt the snows & glaciers, which also exit with the rains. Some of our glaciers are gone & the majority on in recession. When the sun upgrades to normal, will Hefaistos consider Greenland 'rain rivers' iffy, when Greenland ice loss hits 1000 cubic kilometers per year, or 5000 per year, or 10,000 per year? 
« Last Edit: October 31, 2018, 01:09:26 AM by litesong »

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Re: Ice Apocalypse - MULTIPLE METERS SEA LEVEL RISE (narrated video)
« Reply #209 on: October 31, 2018, 01:15:37 PM »
We’ve entered some profoundly unfamiliar planetary territory.
https://mashable.com/article/climate-change-carbon-pollution-15-million-years/
Omnia mirari, etiam tritissima.

Hefaistos

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Re: Ice Apocalypse - MULTIPLE METERS SEA LEVEL RISE (narrated video)
« Reply #210 on: October 31, 2018, 03:04:35 PM »
I don't think it's "gravitationally unstable", especially as compared to parts of Antarctic's ice......  Even if there are 'rain rivers' coming in, the quantity of rain water is negligible compared to the thousands of meters of glacier ice.
First, comparing Greenland to Antarctica can't be done for many reasons, one being that West Antarctica is nearly a set of above sea level islands & underwater grounding rock islands. Second, already the center core of Greenland is in uplift. Third, those 'rain rivers' aren't considered "iffy", since Greenland is losing sea ice, as much as 400+ cubic kilometers per year, even tho total solar irradiation has been low for 12 years. When the Pineapple Express pours on our Cascade Mountains in Washington state, the rain rivers, not only pour into our valleys, but melt the snows & glaciers, which also exit with the rains. Some of our glaciers are gone & the majority on in recession. When the sun upgrades to normal, will Hefaistos consider Greenland 'rain rivers' iffy, when Greenland ice loss hits 1000 cubic kilometers per year, or 5000 per year, or 10,000 per year?
Sorry, but when you quoted me, you omitted an important part of the argument. Here is what I wrote: "I don't think it's "gravitationally unstable", especially as compared to parts of Antarctic's ice.
It's got to be a very slow process warming the glaciers up, especially as it seems that Greenland is about to replace the Arctic sea as the north cold pole, once ASI is gone.
Even if there are 'rain rivers' coming in, the quantity of rain water is negligible compared to the thousands of meters of glacier ice."

GIS is on high altitudes, it's freezing temperatures most of the year. Rain rivers will eat the ice sheet away on the edges, at lower altitudes, but higher up, where most of GIS is, 'rain rivers' will be 'snow cannons', and the snow that falls will eventually be compressed to form new ice.

AbruptSLR

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Re: Ice Apocalypse - MULTIPLE METERS SEA LEVEL RISE (narrated video)
« Reply #211 on: October 31, 2018, 04:41:50 PM »
While certainly the WAIS is more susceptible to rapid collapse from hydrofacturing of ice shelves followed by cliff failures of the subsequently exposed marine glacier ice cliffs; nevertheless, the GIS has a significant number of marine terminating glacier that are subject to accelerating rates of cliff failures (with continued global warming) as indicated by the linked reference and associated image:

Tanja Schlemm and Anders Levermann (2018), "A simple stress-based cliff-calving law", The Cryosphere Discuss., https://doi.org/10.5194/tc-2018-205

https://www.the-cryosphere-discuss.net/tc-2018-205/tc-2018-205.pdf

Abstract. Over large coastal regions in Greenland and Antarctica the ice sheet calves directly into the ocean. In contrast to ice-shelf calving, an increase in cliff calving directly contributes to sea-level rise and a monotonously increasing calving rate with ice thickness can constitute a self-amplifying ice loss mechanism that may significantly alter sea-level projections both of Greenland and Antarctica. Here we seek to derive a minimalistic stress-based parameterization for cliff calving. To this end we compute the stress field for a glacier with a simplified two-dimensional geometry from the two-dimensional Stokes equation. First we assume a constant yield stress to derive the failure region at the glacier front from the stress field within the ice sheet. Secondly, we assume a constant response time of ice failure due to exceedance of the yield stress. With this strongly constraining but very simple set of assumption we propose a cliff-calving law where the calving rate follows a power-law dependence on the freeboard of the ice with exponents between 2 and 3 depending on the relative water depth at the calving front. The critical freeboard below which the ice front is stable decreases with increasing relative water depth of the calving front. For a dry water front it is, for example, 75m. The purpose of this study is not to provide a comprehensive calving law, but to derive a particularly simple equation with a transparent and minimalistic set of assumptions.

Edit: At risk of stating the obvious, as the calving face retreats down a negatively slope into a marine basin such as either the Byrd Subglacial Basin, BSB (in West Antarctica), or the central basin beneath the Greenland Ice Sheet, both the relative water depth and the freeboard of the associated ice cliff increase which leads to a positive feedback on the rate of acceleration of calving.  Furthermore, the keel draft of the associated calved icebergs are always shallower than the associated water depth, and thus the associated icebergs may float out of the glacier gateway into the open ocean, and/or contribute immediately to sea level rise by floating above the submerged basin floor and pushing associate water out the glacier gateway into the open ocean.

Edit2: Of course it is also true that if the calving face of marine glacier retreats into a submerged basin (like BSB or the central Greenland Basin) that the calved icebergs might (or might not) form a sufficiently dense ice mélange that could buttress and thus inhibit further ice cliff failures until the ice mélange disperses.
« Last Edit: October 31, 2018, 05:49:32 PM by AbruptSLR »
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AbruptSLR

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Re: Ice Apocalypse - MULTIPLE METERS SEA LEVEL RISE (narrated video)
« Reply #212 on: October 31, 2018, 06:05:09 PM »
Pretty scary news (that CaCO3 is currently being dissolved from the seafloor) even for Halloween, in that this happened during the PETM, and it took Earth over 100,000 years to recover from that event:

Olivier Sulpis, Bernard P. Boudreau, Alfonso Mucci, Chris Jenkins, David S. Trossman, Brian K. Arbic, and Robert M. Key (published ahead of print October 29, 2018), "Current CaCO3 dissolution at the seafloor caused by anthropogenic CO2", PNAS, https://doi.org/10.1073/pnas.1804250115

http://www.pnas.org/content/early/2018/10/23/1804250115

Significance

The geological record contains numerous examples of “greenhouse periods” and ocean acidification episodes, where the spreading of corrosive (CO2-enriched) bottom waters enhances the dissolution of CaCO3 minerals delivered to the seafloor or contained within deep-sea sediments. The dissolution of sedimentary CaCO3 neutralizes excess CO2, thus preventing runaway acidification, and acts as a negative-feedback mechanism in regulating atmospheric CO2 levels over timescales of centuries to millennia. We report an observation-based indication and quantification of significant CaCO3 dissolution at the seafloor caused by man-made CO2. This dissolution is already occurring at various locations in the deep ocean, particularly in the northern Atlantic and near the Southern Ocean, where the bottom waters are young and rich in anthropogenic CO2.

Abstract

Oceanic uptake of anthropogenic CO2 leads to decreased pH, carbonate ion concentration, and saturation state with respect to CaCO3 minerals, causing increased dissolution of these minerals at the deep seafloor. This additional dissolution will figure prominently in the neutralization of man-made CO2. However, there has been no concerted assessment of the current extent of anthropogenic CaCO3 dissolution at the deep seafloor. Here, recent databases of bottom-water chemistry, benthic currents, and CaCO3 content of deep-sea sediments are combined with a rate model to derive the global distribution of benthic calcite dissolution rates and obtain primary confirmation of an anthropogenic component. By comparing preindustrial with present-day rates, we determine that significant anthropogenic dissolution now occurs in the western North Atlantic, amounting to 40–100% of the total seafloor dissolution at its most intense locations. At these locations, the calcite compensation depth has risen ∼300 m. Increased benthic dissolution was also revealed at various hot spots in the southern extent of the Atlantic, Indian, and Pacific Oceans. Our findings place constraints on future predictions of ocean acidification, are consequential to the fate of benthic calcifiers, and indicate that a by-product of human activities is currently altering the geological record of the deep sea.
« Last Edit: October 31, 2018, 06:43:14 PM by AbruptSLR »
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litesong

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Re: Ice Apocalypse - MULTIPLE METERS SEA LEVEL RISE (narrated video)
« Reply #213 on: October 31, 2018, 06:12:47 PM »
Rain rivers will eat the ice sheet away on the edges, at lower altitudes, but higher up, where most of GIS is, 'rain rivers' will be 'snow cannons', and the snow that falls will eventually be compressed to form new ice.
With AGW warming the planet, some warmer snows which used to "be compressed to form new ice" aren't forming new ices. Also, any rain that is falling is warmer rain, that melts more snow & ice. Classic examples are lower latitude mountains which are now losing their glaciers. Our Washington state Cascade Mountains are losing glaciers rapidly, even on Mt. Rainier. Many of our late summer rivers into early fall have decreased their mass flow rates due to no longer existing glaciers which used to supply river & creek waters in the last times before fall rains & snows began. Increasing AGW effects as at the low latitude conditions, are already nibbling at the fringes of Greenland (& yes, at Antarctica too) & surprisingly at higher Greenland elevations.
 Yeah, the Greenland Ice Sheet is not stable.

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Re: Ice Apocalypse - MULTIPLE METERS SEA LEVEL RISE (narrated video)
« Reply #214 on: October 31, 2018, 06:29:16 PM »
We’ve entered some profoundly unfamiliar planetary territory.
https://mashable.com/article/climate-change-carbon-pollution-15-million-years/
First, it was less than 600,000 years ago, then 600,000 years ago, then 800,000 years ago. Now scientists are saying CO2 is higher than 15 million years ago? This here AGW stuff.... its a time machine.

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Re: Ice Apocalypse - MULTIPLE METERS SEA LEVEL RISE (narrated video)
« Reply #215 on: October 31, 2018, 09:24:55 PM »
Unfortunately litesong, no-one has invented a time machine that can take us back.
It's the speed that's the big issue here, followed by the speed and then in third place, the speed.

Using the Eeemian as an analogy, with Greenland as the new "cold pole" doesn't really work. First, we now know that the year-to-year variability in SMB can be high and is highly dependent on the weather. Second, the ice on Greenland covers "only" ~1,700,000 km², the Arctic Ocean ~14,000,000 km². Third, during the Eemian it was warmer summers that melted the ice thanks to different orbital parameters. Fourth, CO2 levels during the Eemian peaked around 280ppm.



Hopefully GRACE-FO starts producing soon. It won't help us mitigate though.
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AbruptSLR

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Re: Ice Apocalypse - MULTIPLE METERS SEA LEVEL RISE (narrated video)
« Reply #216 on: November 01, 2018, 03:54:43 PM »
The linked research indicates that: a) the oceans have absorbed 60% heat than assumed by AR5; b) The carbon budget assumed by AR5 must be decreased by at least 25%; and c) the range of climate sensitivity is higher than assumed by AR5:

Title: "Earth's oceans have absorbed 60 percent more heat than previously thought"

https://m.phys.org/news/2018-10-earth-oceans-absorbed-percent-previously.html

Extract: "First author Laure Resplandy, an assistant professor of geosciences and the Princeton Environmental Institute, said that her and her co-authors' estimate is more than 60 percent higher than the figure in the 2014 Fifth Assessment Report on climate change from the United Nations Intergovernmental Panel on Climate Change (IPCC).

Scientists know that the ocean takes up roughly 90 percent of all the excess energy produced as the Earth warms, so knowing the actual amount of energy makes it possible to estimate the surface warming we can expect, said co-author Ralph Keeling, a Scripps Oceanography geophysicist and Resplandy's former postdoctoral adviser.

"The result significantly increases the confidence we can place in estimates of ocean warming and therefore helps reduce uncertainty in the climate sensitivity, particularly closing off the possibility of very low climate sensitivity," Keeling said.

The researchers' findings suggest that if society is to prevent temperatures from rising above that mark, emissions of carbon dioxide, the chief greenhouse gas produced by human activities, must be reduced by 25 percent compared to what was previously estimated, Resplandy said."

See also:
 
Resplandy et al. (Oct 31 2018), "Quantification of ocean heat uptake from changes in atmospheric O₂ and CO₂ composition", Nature 563, 105-108, doi: https://doi.org/10.1038/s41586-018-0651-8

http://www.nature.com/articles/s41586-018-0651-8

Finally, I note that Resplandy's calculation that the carbon budget should be reduced by 25% is essentially the same thing as saying that TCR is 25% larger than estimated by AR5.
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AbruptSLR

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Re: Ice Apocalypse - MULTIPLE METERS SEA LEVEL RISE (narrated video)
« Reply #217 on: November 05, 2018, 11:44:56 PM »
The linked reference indicates that 128 kya, the bipolar seesaw contributed significantly to the warming of the Antarctic and Southern Ocean temperatures, due ice melting in the Northern Hemisphere.  This supports Hanson's ice-climate feedback mechanism and further indicates that ice mass loss from Greenland will accelerated ice mass loss from Antarctica:

Max D. Holloway et al. (23 October 2018), "Simulating the 128‐ka Antarctic Climate Response to Northern Hemisphere Ice Sheet Melting Using the Isotope‐Enabled HadCM3", Geophysical Research Letters, https://doi.org/10.1029/2018GL079647

https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2018GL079647

Abstract
Warmer than present Antarctic and Southern Ocean temperatures during the last interglacial, approximately 128,000 years ago, have been attributed to changes in north‐south ocean heat transport, causing opposing hemispheric temperature anomalies. We investigate the magnitude of Antarctic warming and Antarctic ice core isotopic enrichment in response to Northern Hemisphere meltwater input during the early last interglacial. A 1,600‐year HadCM3 simulation driven by 0.25 Sv of meltwater input reproduces 50–60% of the peak Southern Ocean summer sea surface temperature anomaly, sea ice retreat, and ice core isotope enrichment. We also find a robust increase in the proportion of cold season precipitation during the last interglacial, leading to lower isotopic values at the Antarctic ice core sites. These results suggest that a HadCM3 simulation including 0.25 Sv for 3,000–4,000 years would reconcile the last interglacial observations, providing a potential solution for the last interglacial missing heat problem.

Plain Language Summary
The Antarctic isotope and temperature maximum, which occurred approximately 128,000 years Before Present (yBP) during the warmer than present last interglacial period, is hypothesized to have resulted from a slowdown in northward ocean heat transport due to ice sheet melting into the North Atlantic—a mechanism known as the bipolar seesaw. We test this hypothesis by running and analyzing long, fully coupled, isotope‐enabled climate model simulations, which include meltwater entering the North Atlantic, for this critical period 128,000 yBP. Results are evaluated against ocean and ice core data. After 1,600 years, we simulate 55% of the peak Southern Ocean summer sea surface temperature anomaly, 50% of the estimated winter sea ice retreat, and 60% of the ice core isotope enrichment reconstructed during the early last interglacial Antarctic climate optimum.
« Last Edit: November 05, 2018, 11:56:38 PM by AbruptSLR »
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Re: Ice Apocalypse - MULTIPLE METERS SEA LEVEL RISE (narrated video)
« Reply #218 on: November 08, 2018, 07:11:23 AM »
Hopefully GRACE-FO starts producing soon. It won't help us mitigate though.
I'm a bit sleepy but amazing timing by NASA and GFZ.  ;D

News | November 1, 2018
GRACE-FO Resumes Data Collection
https://www.jpl.nasa.gov/news/news.php?feature=7276
Omnia mirari, etiam tritissima.