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AbruptSLR

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Re: Ice Apocalypse - MULTIPLE METERS SEA LEVEL RISE (narrated video)
« Reply #3150 on: May 08, 2020, 04:06:03 PM »
The linked reference used a survey of experts to indicate that AR5 likely underestimated the likely range of SLR.  For those who do not know it is common for consensus climate science to increase their SLR projections every few years, and I expect this trend for increasing consensus SLR projections every few years to continue until MICI-type failures are seen in the field by which time it will be too late to prevent abrupt SLR:

Horton, B.P., Khan, N.S., Cahill, N. et al. Estimating global mean sea-level rise and its uncertainties by 2100 and 2300 from an expert survey. npj Clim Atmos Sci 3, 18 (2020). https://doi.org/10.1038/s41612-020-0121-5

https://www.nature.com/articles/s41612-020-0121-5

Abstract: "Sea-level rise projections and knowledge of their uncertainties are vital to make informed mitigation and adaptation decisions. To elicit projections from members of the scientific community regarding future global mean sea-level (GMSL) rise, we repeated a survey originally conducted five years ago. Under Representative Concentration Pathway (RCP) 2.6, 106 experts projected a likely (central 66% probability) GMSL rise of 0.30–0.65 m by 2100, and 0.54–2.15 m by 2300, relative to 1986–2005. Under RCP 8.5, the same experts projected a likely GMSL rise of 0.63–1.32 m by 2100, and 1.67–5.61 m by 2300. Expert projections for 2100 are similar to those from the original survey, although the projection for 2300 has extended tails and is higher than the original survey. Experts give a likelihood of 42% (original survey) and 45% (current survey) that under the high-emissions scenario GMSL rise will exceed the upper bound (0.98 m) of the likely range estimated by the Fifth Assessment Report of the Intergovernmental Panel on Climate Change, which is considered to have an exceedance likelihood of 17%. Responses to open-ended questions suggest that the increases in upper-end estimates and uncertainties arose from recent influential studies about the impact of marine ice cliff instability on the meltwater contribution to GMSL rise from the Antarctic Ice Sheet."
“It is not the strongest or the most intelligent who will survive but those who can best manage change.”
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Re: Ice Apocalypse - MULTIPLE METERS SEA LEVEL RISE (narrated video)
« Reply #3151 on: May 08, 2020, 05:27:17 PM »
The linked article presents an edited extract from The Future We Choose: Surviving the Climate Crisis by Christiana Figueres and Tom Rivett-Carnac; which considers a consensus climate science evaluation of a worst case scenario for the climate in 2050; which is bad enough for most people:

Title: "‘The only uncertainty is how long we’ll last’: a worst case scenario for the climate in 2050"

https://www.theguardian.com/environment/2020/feb/15/worst-case-scenario-2050-climate-crisis-future-we-choose-christiana-figueres-tom-rivett-carnac

“It is not the strongest or the most intelligent who will survive but those who can best manage change.”
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Re: Ice Apocalypse - MULTIPLE METERS SEA LEVEL RISE (narrated video)
« Reply #3152 on: May 08, 2020, 06:48:50 PM »
The linked reference, & associated article, discusses the reasons why the SST for the Southern Ocean cooled between the early 1980s and the early 2010s, and concludes that: "… these trends are predominantly caused by an increased wind‐driven northward sea‐ice transport, enhancing the extraction of freshwater near Antarctica and releasing it in the open ocean."

The study also concludes that: "In our model, the resulting freshening leads to a surface cooling, because the mixing of these waters with the warmer waters below is hindered. Thereby, the heat stays below the ocean's surface and cannot be released to the atmosphere. This retention of large amounts of heat at the subsurface possibly enhanced the melting of the Antarctic glaciers and possibly contributed to the slowdown of global warming over this period."

Therefore, the wind-driven (likely accelerated by the Antarctic ozone hole) northward transport of Antarctic sea-ice enhanced the upwelling of warm CDW, which was then advected beneath key Antarctic ice shelves to key marine glacier grounding lines.  This mechanism is included in Hansen et al (2016) ice-climate simulations:

F. Alexander Haumann, Nicolas Gruber, Matthias Münnich. Sea‐Ice Induced Southern Ocean Subsurface Warming and Surface Cooling in a Warming Climate. AGU Advances, 2020; 1 (2) DOI: 10.1029/2019AV000132

https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2019AV000132

Abstract
Much of the Southern Ocean surface south of 55° S cooled and freshened between at least the early 1980s and the early 2010s. Many processes have been proposed to explain the unexpected cooling, including increased winds or freshwater fluxes. However, these mechanisms so far failed to fully explain the surface trends and the concurrent subsurface warming (100 to 500 m). Here, we argue that these trends are predominantly caused by an increased wind‐driven northward sea‐ice transport, enhancing the extraction of freshwater near Antarctica and releasing it in the open ocean. This conclusion is based on factorial experiments with a regional ocean model. In all experiments with an enhanced northward sea‐ice transport, a strengthened salinity‐dominated stratification cools the open‐ocean surface waters between the Subantarctic Front and the sea‐ice edge. The strengthened stratification reduces the downward mixing of cold surface water and the upward heat loss of the warmer waters below, thus warming the subsurface. This sea‐ice induced subsurface warming mostly occurs around West Antarctica, where it likely enhances ice‐shelf melting. Moreover, the subsurface warming could account for about 8 ± 2% of the global ocean heat content increase between 1982 and 2011. Antarctic sea‐ice changes thereby may have contributed to the slowdown of global surface warming over this period. Our conclusions are robust across all considered sensitivity cases, although the trend magnitude is sensitive to forcing uncertainties and the model's mean state. It remains unclear whether these sea‐ice induced changes are associated with natural variability or reflect a response to anthropogenic forcing.

Plain Language Summary
While most of the global ocean surface has been warming in response to increasing atmospheric greenhouse‐gas concentrations, parts of the polar Southern Ocean surface have been cooling over recent decades. This cooling seems surprising, since most climate models suggest that also this region should have been warming. Using a regional ocean model, we find that the cooling can be reproduced when forcing the model with observed sea‐ice changes. Sea ice forms during the cold winter mostly along the Antarctic coast, leaving the salt that is contained in the seawater behind, and is then being pushed to the open ocean by strong winds. In the open ocean, the sea ice melts and makes the surface waters fresher there. This lateral sea‐ice transport has strengthened over recent decades, most likely due to stronger winds. In our model, the resulting freshening leads to a surface cooling, because the mixing of these waters with the warmer waters below is hindered. Thereby, the heat stays below the ocean's surface and cannot be released to the atmosphere. This retention of large amounts of heat at the subsurface possibly enhanced the melting of the Antarctic glaciers and possibly contributed to the slowdown of global warming over this period.

See also:

Title: "One small area of ocean not changed by global warming"

https://www.sciencedaily.com/releases/2020/05/200506123738.htm

Extract: "In a paper just published in the journal AGU Advances, the scientists use a series of simulations to show that sea-ice changes are the most probable cause for the cooling of the surface waters in the Southern Ocean. Only when Alex Haumann, lead author and Professor Gruber's former doctoral student, and the team incorporated the observed changes in sea ice into the model were they able to correctly replicate the observed pattern of the temperature changes. When they omitted this effect and only took into account the other potential factors -- such as a more vigorous ocean circulation or increased freshwater fluxes from the melting of the Antarctic glaciers -- the pattern was not accurately simulated.

Cooling in just one area of the ocean should not be interpreted as a reduction of the long-term warming of the global climate system as a whole. It is merely a redistribution of heat in the Southern Ocean from the surface to the deeper layers of the ocean. "We assume the strong winds pushing the sea ice in the Southern Ocean northward are potentially a side-effect of climate change," Gruber stresses. "Climate change is clearly man-made and cannot be disputed simply because one area of the ocean shows signs of cooling."

In addition, the current study went only up to 2011. "We have observed a trend reversal since 2015. The sea ice around the Antarctic is now starting to recede at a rapid rate," says the ETH Professor. "And this is very much in line with the overall trend of continuing global warming.""
« Last Edit: May 09, 2020, 12:04:05 AM by AbruptSLR »
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Re: Ice Apocalypse - MULTIPLE METERS SEA LEVEL RISE (narrated video)
« Reply #3153 on: May 09, 2020, 12:03:12 AM »
The linked article discusses research that confirms that climate change is contributing to increasing frequency and intensity of extreme weather events:

Title: "Climate change attribution"

https://www.technologyreview.com/technology/climate-change-attribution/

Extract: "The group, World Weather Attribution, had compared high-resolution computer simulations of worlds where climate change did and didn’t occur. In the former, the world we live in, the severe storm was as much as 2.6 times more likely—and up to 28% more intense."
“It is not the strongest or the most intelligent who will survive but those who can best manage change.”
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Re: Ice Apocalypse - MULTIPLE METERS SEA LEVEL RISE (narrated video)
« Reply #3154 on: May 09, 2020, 09:31:43 AM »
The linked reference, and associated article, indicates that the combination of heat and humidity is making many areas of the Earth to severe for human tolerance decades sooner than previously projected by consensus climate scientists.  Also, remember that water vapor is a GHG.

Colin Raymond et al. (08 May 2020), "The emergence of heat and humidity too severe for human tolerance", Science Advances, Vol. 6, no. 19, eaaw1838, DOI: 10.1126/sciadv.aaw1838

https://advances.sciencemag.org/content/6/19/eaaw1838

Abstract: "Humans’ ability to efficiently shed heat has enabled us to range over every continent, but a wet-bulb temperature (TW) of 35°C marks our upper physiological limit, and much lower values have serious health and productivity impacts. Climate models project the first 35°C TW occurrences by the mid-21st century. However, a comprehensive evaluation of weather station data shows that some coastal subtropical locations have already reported a TW of 35°C and that extreme humid heat overall has more than doubled in frequency since 1979. Recent exceedances of 35°C in global maximum sea surface temperature provide further support for the validity of these dangerously high TW values. We find the most extreme humid heat is highly localized in both space and time and is correspondingly substantially underestimated in reanalysis products. Our findings thus underscore the serious challenge posed by humid heat that is more intense than previously reported and increasingly severe."

Caption: "Fig. 2 Global trends in extreme humid heat.
(A to D) Annual global counts of TW exceedances above the thresholds labeled on the respective panel, from HadISD (black, right axes, with units of station days) and ERA-Interim grid points (gray, left axes, with units of grid-point days). We consider only HadISD stations with at least 50% data availability over 1979–2017. Correlations between the series are annotated in the top left of each panel, and dotted lines highlight linear trends. (E) Annual global maximum TW in ERA-Interim. (F) The line plot shows global mean annual temperature anomalies (relative to 1850–1879) according to HadCRUT4 (40), which we use to approximate each year’s observed warming since preindustrial; circles indicate HadISD station occurrences of TW exceeding 35°C, with radius linearly proportional to global annual count, measured in station days."

See also:

Title: "Lethal levels of heat and humidity are gripping global ‘hot spots’ sooner than expected"

https://www.sciencemag.org/news/2020/05/lethal-levels-heat-and-humidity-are-gripping-global-hot-spots-sooner-expected

Extract: "From the shores of the Persian Gulf to the foothills of Mexico’s Sierra Madre Occidental mountains, hot weather is reaching levels humans can’t endure. An analysis of 4 decades of data from thousands of weather stations shows that a handful of hot spots around the globe are experiencing a potentially lethal mix of heat and humidity—something most of these places weren’t expected to experience until midcentury.

“Previous studies projected that this would happen several decades from now, but this shows it’s happening right now,” says Colin Raymond, a postdoctoral researcher at NASA’s Jet Propulsion Laboratory who led the study."

“It is not the strongest or the most intelligent who will survive but those who can best manage change.”
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Re: Ice Apocalypse - MULTIPLE METERS SEA LEVEL RISE (narrated video)
« Reply #3155 on: May 09, 2020, 08:32:56 PM »
The reported recent surge in deforestation of the Amazon rainforest pushes this somewhat fragile ecosystem closer to a climate tipping point:

Title: "Deforestation in Brazil's Amazon surges, Bolsonaro readies troops"

https://www.reuters.com/article/us-brazil-environment/deforestation-in-brazils-amazon-surges-in-april-idUSKBN22K1U1

Extract: "Deforestation in Brazil’s Amazon rainforest rose sharply in April, government data showed on Friday, as the coronavirus outbreak keeps many environmental enforcers out of the field and the country prepares to deploy troops to fight illegal logging.

Destruction in Brazil’s portion of the Amazon increased 64% in April, compared with the same month a year ago, according to preliminary satellite data from space research agency INPE.

In the first four months of the year, Amazon deforestation was up 55% from a year ago to 1,202 square kilometers (464 square miles), according to the INPE data."
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Re: Ice Apocalypse - MULTIPLE METERS SEA LEVEL RISE (narrated video)
« Reply #3156 on: May 10, 2020, 01:55:05 AM »
Using models accounting for future warming, the authors of the linked reference predict a future decline in the African carbon sink and a rapid weakening of the Amazonian carbon sink.  After the 2030s, the Amazonian tropical forests will stop sequestering carbon, according to their analysis. They conclude that the uptake of carbon from intact tropical forests peaked in the 1990s.

Wannes Hubau et al. (2020), "Asynchronous carbon sink saturation in African and Amazonian tropical forests", Nature, Vol. 579, https://doi.org/10.1038/s41586-020-2035-0

https://www.nature.com/articles/s41586-020-2035-0.epdf?referrer_access_token=1JyC8Qk9bocUSjMvwF1ScNRgN0jAjWel9jnR3ZoTv0NOJ2x2BsrUNZyzCBuuL0UUqQjPW2euF71wbnss7bZVTypLc0eJu3wcwXkQBGokyA9HW2k-okTMHDdectG92AB7UCaAEYubgKcBIjfvWwAarBHNAQlggxcW6gKC8EBuatXyyNG4lsNoKGBuz6jwneDBL85C6ZibPhm8YlwdenuepVVP3nfandk-FdksbHp95BMzbOlkWsOdA_w-AgEHUgpR--O3YMfs5rGobLgW3dErAFzL2HiJnxMDdXmrUYWB9BmXvV6tOn6btzbsOf6thVTa&tracking_referrer=www.theguardian.com&utm_campaign=Hot%20News&utm_source=hs_email&utm_medium=email&utm_content=84317976&_hsenc=p2ANqtz-8UPQfxoelrSvfbdYQCIkzqlCfBROkJ5jKELKAq3Pgh1uafh2U1uOzeDyMDWDEuNhhanL130IV3OuvMP6uUTYnT4uig2Q&_hsmi=84317976

« Last Edit: May 10, 2020, 05:42:36 PM by AbruptSLR »
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Re: Ice Apocalypse - MULTIPLE METERS SEA LEVEL RISE (narrated video)
« Reply #3157 on: May 10, 2020, 05:41:58 PM »
Just a quick reminder that not only with the American West trending towards a 'megadrought' that will promote more wildfires; but also that climate change will continue to make currently dry regions more dry and currently wet regions more wet; which will stress vegetation around the world:

Title: "Ominous trend in American West could signal a looming "megadrought""

https://www.msn.com/en-us/news/other/ominous-trend-in-american-west-could-signal-a-looming-megadrought/ar-BB13QqsP

Extract: ""The persistence of the drought conditions, in the Colorado River basin especially, is essentially unprecedented in human history," John Fleck, author of "Water is for Fighting Over," told CBS News' John Blackstone. 

A team of scientists is researching megadroughts that have lasted as long as 40 years, using tree ring evidence going back 1,200 years."
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Re: Ice Apocalypse - MULTIPLE METERS SEA LEVEL RISE (narrated video)
« Reply #3158 on: May 10, 2020, 05:59:45 PM »
The linked reference, and associated article, indicate that consensus climate science is currently significantly underestimating CO2 emissions from inland waters that exhibit complete or partial desiccation or that have vanished due to global change that has exposed the underlying sediments to the atmosphere.  Their research also indicates that this underestimated source of CO2 emissions will likely increase with continuing climate change:

Keller, P.S., Catalán, N., von Schiller, D. et al. Global CO2 emissions from dry inland waters share common drivers across ecosystems. Nat Commun 11, 2126 (2020). https://doi.org/10.1038/s41467-020-15929-y

https://www.nature.com/articles/s41467-020-15929-y

Abstract: "Many inland waters exhibit complete or partial desiccation, or have vanished due to global change, exposing sediments to the atmosphere. Yet, data on carbon dioxide (CO2) emissions from these sediments are too scarce to upscale emissions for global estimates or to understand their fundamental drivers. Here, we present the results of a global survey covering 196 dry inland waters across diverse ecosystem types and climate zones. We show that their CO2 emissions share fundamental drivers and constitute a substantial fraction of the carbon cycled by inland waters. CO2 emissions were consistent across ecosystem types and climate zones, with local characteristics explaining much of the variability. Accounting for such emissions increases global estimates of carbon emissions from inland waters by 6% (~0.12 Pg C y−1). Our results indicate that emissions from dry inland waters represent a significant and likely increasing component of the inland waters carbon cycle."

See also:

Title: "CO2 emissions from inland waters are vastly underestimated"

https://www.earth.com/news/co2-emissions-from-inland-waters-hugely-underestimated/

Extract: "Global calculations of CO2 emissions from inland waters have been widely underestimated, according to a study led by scientists at the Helmholtz Centre for Environmental Research (UFZ). The researchers found that lakes and reservoirs that dry up periodically play an important role in the global carbon cycle, yet have been largely unaccounted for."
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Re: Ice Apocalypse - MULTIPLE METERS SEA LEVEL RISE (narrated video)
« Reply #3159 on: May 10, 2020, 06:04:28 PM »
The linked reference indicates that improved modeling of future thermokarst behavior in northeast Siberia indicates that:

"... by 2100 thaw-affected carbon could be up to three-fold (twelve-fold) under RCP4.5 (RCP8.5), of what is projected if thermokarst-inducing processes are ignored."

AR5 projections ignored this significant positive feedback mechanism.

Nitzbon, J., Westermann, S., Langer, M. et al. Fast response of cold ice-rich permafrost in northeast Siberia to a warming climate. Nat Commun 11, 2201 (2020). https://doi.org/10.1038/s41467-020-15725-8

https://www.nature.com/articles/s41467-020-15725-8

Abstract: "The ice- and organic-rich permafrost of the northeast Siberian Arctic lowlands (NESAL) has been projected to remain stable beyond 2100, even under pessimistic climate warming scenarios. However, the numerical models used for these projections lack processes which induce widespread landscape change termed thermokarst, precluding realistic simulation of permafrost thaw in such ice-rich terrain. Here, we consider thermokarst-inducing processes in a numerical model and show that substantial permafrost degradation, involving widespread landscape collapse, is projected for the NESAL under strong warming (RCP8.5), while thawing is moderated by stabilizing feedbacks under moderate warming (RCP4.5). We estimate that by 2100 thaw-affected carbon could be up to three-fold (twelve-fold) under RCP4.5 (RCP8.5), of what is projected if thermokarst-inducing processes are ignored. Our study provides progress towards robust assessments of the global permafrost carbon–climate feedback by Earth system models, and underlines the importance of mitigating climate change to limit its impacts on permafrost ecosystems."
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Re: Ice Apocalypse - MULTIPLE METERS SEA LEVEL RISE (narrated video)
« Reply #3160 on: May 10, 2020, 06:13:00 PM »
The linked article indicates that:

"The boreal forest that rings the northern tier of the world is burning at a rate unseen in 10,000 years."

This is not good news, especially when we consider that the COVID-19 outbreak in Russia will suppress wildfire fighting effort in Siberia this year:

Title: "Siberian Wildfires Have Burned an Area More Than Three Times the Size of Delaware"

https://earther.gizmodo.com/we-should-probably-talk-about-the-huge-wildfires-in-sib-1843205527

Extract: " Russia has had a rough go of it this year. It set a record for its hottest winter ever and Moscow basically skipped the season entirely. The heat has continued into spring, and now, the Siberian countryside is on fire. Emergencies Minister Yevgeny Zinichev called it a “critical situation,” according to the Siberian Times.

The boreal forest that rings the northern tier of the world is burning at a rate unseen in 10,000 years. Rising temperatures have played a role by drying out forests and priming them to burn and creating conditions where fires are more likely to spread. That releases carbon dioxide, ensuring ever larger fires by heating up the planet further."
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Re: Ice Apocalypse - MULTIPLE METERS SEA LEVEL RISE (narrated video)
« Reply #3161 on: May 10, 2020, 06:50:43 PM »
The linked reference not only finds that the mean annual air temperature, MAAT, in Northwestern Alaska is already within the range that consensus climate models projected would not occur until 2100 following RCP6.0, but also that the projected drainage of future thermokarst lakes will reduce the ability of the associate permafrost areas to sequester carbon in the lake bed sediments as indicated by the following extract:

"Recent MAAT are already within the range of predictions by UAF SNAP ensemble climate predictions in scenario RCP6.0 for 2100.  With MAAT in 2019 exceeding 0 °C at the nearby Kotzebue, Alaska climate station for the first time since continuous recording started in 1949, permafrost aggradation in drained lake basins will become less likely after drainage, strongly decreasing the potential for freeze-locking carbon sequestered in lake sediments, signifying a prominent regime shift in ice-rich permafrost lowland regions."

Nitze, I., Cooley, S., Duguay, C., Jones, B. M., and Grosse, G.: The catastrophic thermokarst lake drainage events of 2018 in northwestern Alaska: Fast-forward into the future, The Cryosphere Discuss., https://doi.org/10.5194/tc-2020-106, in review, 2020.

https://www.the-cryosphere-discuss.net/tc-2020-106/

Abstract. Northwestern Alaska has been highly affected by changing climatic patterns with new temperature and precipitation maxima over the recent years. In particular, the Baldwin and northern Seward peninsulas are characterized by an abundance of thermokarst lakes that are highly dynamic and prone to lake drainage, like many other regions at the southern margins of continuous permafrost. We used Sentinel-1 synthetic aperture radar (SAR) and Planet CubeSat optical remote sensing data to analyze recently observed widespread lake drainage. We then used synoptic weather data, climate model outputs and lake-ice growth simulations to analyze potential drivers and future pathways of lake drainage in this region. Following the warmest and wettest winter on record in 2017/2018, 192 lakes were identified to have completely or partially drained in early summer 2018, which exceeded the average drainage rate by a factor of ~ 10 and doubled the rates of the previous extreme lake drainage years of 2005 and 2006. The combination of abundant rain- and snowfall and extremely warm mean annual air temperatures (MAAT), close to 0 °C, may have led to the destabilization of permafrost around the lake margins. Rapid snow melt and high amounts of excess meltwater further promoted rapid lateral breaching at lake shores and consequently sudden drainage of some of the largest lakes of the study region that likely persisted for millenia. We hypothesize that permafrost destabilization and lake drainage will accelerate and become the dominant drivers of landscape change in this region. Recent MAAT are already within the range of predictions by UAF SNAP ensemble climate predictions in scenario RCP6.0 for 2100. With MAAT in 2019 exceeding 0 °C at the nearby Kotzebue, Alaska climate station for the first time since continuous recording started in 1949, permafrost aggradation in drained lake basins will become less likely after drainage, strongly decreasing the potential for freeze-locking carbon sequestered in lake sediments, signifying a prominent regime shift in ice-rich permafrost lowland regions.

Extract: "The recent events potentially show the fate of lake-rich landscapes in continuous permafrost along its current southern margins, where near-surface permafrost degradation accelerates and permafrost will become discontinuous in the next decades. The colder less dynamic lake-rich coastal plain of northern Alaska may become more dynamic once climatic patterns will have moved towards the middle-to-end of the century.

Under a rapidly warming and wetting climate, in conjunction with ongoing sea ice loss in the Bering Strait, we expect a further intensification of permafrost degradation, reshaping the landscape and a transition from continuous to discontinuous permafrost, and significant changes in hydrology and ecology."
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Re: Ice Apocalypse - MULTIPLE METERS SEA LEVEL RISE (narrated video)
« Reply #3162 on: May 11, 2020, 12:29:25 AM »
As the linked article indicates, it is not a surprise that consensus climate model projections are being exceeded in real time as per the article:

"Most scientists don’t think climate change predictions are too dire — rather, they might not be dire enough. In addition to reducing emissions, municipalities need to prepare for the worst."

Title: "The Planet Is Probably in Worse Shape Than We Can Even Predict"

https://www.vice.com/en_us/article/ep4gyw/the-planet-is-probably-in-worse-shape-than-we-can-even-predict

Extract: "Scientists rely on elaborate computer simulations that use data from the past to predict what will happen in the future, as people pump more greenhouse gases into the atmosphere. The first climate models, developed in the 1960s, were eerily accurate: They correctly predicted how much hotter the world would be today given the increase in greenhouse gas emissions.

Since then, models have been the basis for the UN’s gold-standard reports that have helped policymakers glimpse into what the climate will look like in the coming decades. They’ve also helped politicians figure out, for example, how high to build sea walls to protect cities from sea level rise.

But scientists worry that today’s climate models might not be as good at predicting the next fifty years — even as tools and data have gotten better. Why? Models are only as good as their inputs. Because the facts on the ground are changing so fast, predictive climate models are getting less reliable, and scientists know it.

“It’s not a surprise that we’re being surprised,” said Theodore Scambos, who studies Antarctic ice sheets at the University of Colorado at Boulder. “We're seeing things occur now that we weren’t anticipating because the world has never been like this before.”
...
The bad news is that most of the new research isn’t about processes that could take carbon out of the atmosphere and make climate change less severe. Quite the opposite: Most of the data that scientists are collecting suggests that global heating will be worse than predicted.

“If you watch how the reports have changed,” said Jessica Hellman, the director of the University of Minnesota’s Institute on the Environment, “more of our errors have tended to be underestimations of how bad things could be.”
...
The upshot of that cycle, which is only just starting to be fully understood and worked into the models, is that doubling the amount of carbon dioxide in the atmosphere could lead to warming of up to 5.6 degrees Celsius. That’s a cataclysmic increase and especially concerning because we’re already halfway to doubling CO2 from pre-industrial levels.
...
But there’s a big difference between four and nine feet — and both could be too low. And the models don’t all take into account the worst-case scenario where the ice sheets in West Antarctica collapse, which could raise sea levels more — by about 12 feet.
...
Most scientists don’t think climate change predictions are too dire — rather, they might not be dire enough. In addition to reducing emissions, municipalities need to prepare for the worst."
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Re: Ice Apocalypse - MULTIPLE METERS SEA LEVEL RISE (narrated video)
« Reply #3163 on: May 11, 2020, 04:26:10 PM »
The linked opinion piece indicates that some (many) consensus climate scientists err on the side of least drama, ESLD, because they are concerned that the general public 'can't handle the truth'.  However, this piece suggests that effect climate action will not be taken until humankind reaches a tipping point and moves into what the article call 'emergency mode'.  If so then the ESLD behavior of many consensus climate scientists is delaying the transition of the general public into a mode where it can reach the level of commitment needs transform our collective actions/systems:

Title: "Climate change: Are we getting into emergency mode?"

https://www.rnz.co.nz/news/on-the-inside/399190/climate-change-are-we-getting-into-emergency-mode

Extract: "Opinion - The poet T.S. Eliot once said that 'humankind cannot bear very much reality'. The truth of these words is about to be tested as humanity increasingly wakes up to the reality of climate change.

In the past, some experts have been concerned that if people are presented with the brutal reality of what may be the consequences of climate change, it may overwhelm them. There may be reactions of panic, denial, despair or a head-in-the-sand approach. However another school of thought, lead by ex-NASA climate scientist Dr Jim Hansen, is that scientists should actually be 'less reticent' when talking to the public.

So as public worry about climate change increases, how will it be manifested? Mass panic maybe? Psychologist Dr Margaret Salamon has another theory. She believes that what is happening now, as evidenced by things like Extinction Rebellion and the school strikes, is that people are adopting what she calls emergency mode. She sees this as a very positive climate change development that should be encouraged. She talks about how the US during the second world war moved full-on into such an emergency mode. It then massively transformed its economy and society in the face of an existential threat. Emergency mode is characterised by focusing on the problem as a top priority; making huge allocations of resources to attempt to reduce it; and, citizens pitching in with their talents and resources to address the predicament."
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Re: Ice Apocalypse - MULTIPLE METERS SEA LEVEL RISE (narrated video)
« Reply #3164 on: May 11, 2020, 04:29:18 PM »
This is just a brief reminder of the work of Alley et al. (2019) entitled: "Troughs developed in ice-stream shear margins precondition ice shelves for ocean-driven breakup"; which, includes assessments of one mechanism contributing to the accelerated calving of the PIIS (see images) and other key ice shelves:

Karen E. Alley, Ted A. Scambos, Richard B. Alley and Nicholas Holschuh (09 Oct 2019), "Troughs developed in ice-stream shear margins precondition ice shelves for ocean-driven breakup", Science Advances, Vol. 5, no. 10, eaax2215, DOI: 10.1126/sciadv.aax2215

https://advances.sciencemag.org/content/5/10/eaax2215

Abstract
Floating ice shelves of fast-flowing ice streams are prone to rift initiation and calving originating along zones of rapid shearing at their margins. Predicting future ice-shelf destabilization under a warming ocean scenario, with the resultant reduced buttressing, faster ice flow, and sea-level rise, therefore requires an understanding of the processes that thin and weaken these shear margins. Here, we use satellite data to show that high velocity gradients result in surface troughs along the margins of fast-flowing ice streams. These troughs are advected into ice-shelf margins, where the locally thinned ice floats upward to form basal troughs. Buoyant plumes of warm ocean water beneath ice shelves can be focused into these basal troughs, localizing melting and weakening the ice-shelf margins. This implies that major ice sheet drainages are preconditioned for rapid retreat in response to ocean warming.
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Re: Ice Apocalypse - MULTIPLE METERS SEA LEVEL RISE (narrated video)
« Reply #3165 on: May 11, 2020, 07:36:48 PM »
As Earth System Models become more complex assessing causal relationships between radiative forcing scenarios and frequently nonlinear/dynamic feedback mechanisms becomes more challenging.  Therefore, I provide the linked reference discusses an improved causal discovery algorithm that can improve the attribution process for future climate model projections:

Jakob Runge et al. (27 Nov 2019), "Detecting and quantifying causal associations in large nonlinear time series datasets", Science Advances, Vol. 5, no. 11, eaau4996, DOI: 10.1126/sciadv.aau4996

https://advances.sciencemag.org/content/5/11/eaau4996

Abstract
Identifying causal relationships and quantifying their strength from observational time series data are key problems in disciplines dealing with complex dynamical systems such as the Earth system or the human body. Data-driven causal inference in such systems is challenging since datasets are often high dimensional and nonlinear with limited sample sizes. Here, we introduce a novel method that flexibly combines linear or nonlinear conditional independence tests with a causal discovery algorithm to estimate causal networks from large-scale time series datasets. We validate the method on time series of well-understood physical mechanisms in the climate system and the human heart and using large-scale synthetic datasets mimicking the typical properties of real-world data. The experiments demonstrate that our method outperforms state-of-the-art techniques in detection power, which opens up entirely new possibilities to discover and quantify causal networks from time series across a range of research fields.

Caption: "Fig. 4 Real-world applications.
(A) Tropical climate example of dependencies between monthly surface pressure anomalies for 1948–2012 (T = 780 months) in the West Pacific (WPAC; regions depicted as shaded boxes below nodes), as well as surface air temperature anomalies in the Central (CPAC) and East Pacific (EPAC), and tropical Atlantic (ATL) (65). The left panel shows correlation (Corr), and the right panel shows PCMCI in the ParCorr implementation with τmax = 7 months to also capture long time lags. Significance was assessed at a strict 1% level."
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Re: Ice Apocalypse - MULTIPLE METERS SEA LEVEL RISE (narrated video)
« Reply #3166 on: May 11, 2020, 11:39:47 PM »
The linked reference and two related articles indicate that since 1997 the Beaufort Gyre (associated with the high pressure atmospheric condition shown in the first image) has accumulated an anomalously high amount of ocean heat content within the relatively fresh water accumulated in the gyre; which, could rapidly be released into the Arctic Ocean during sustained atmospheric conditions with a low pressure system over the Beaufort Gyre (see the second image).  Not only would such a relatively rapid release of relatively warm relatively fresh water from the Beaufort Gyre slow down the MOC (which would accelerated warming of the tropical sea surface temperatures) but would also likely result in a relatively abrupt reduction of Arctic sea ice as discussed in the second linked article from 2019.

Mary-Louise Timmermans John Toole and Richard Krishfield (29 Aug 2018), "Warming of the interior Arctic Ocean linked to sea ice losses at the basin margins", Science Advances, Vol. 4, no. 8, eaat6773, DOI: 10.1126/sciadv.aat6773

https://advances.sciencemag.org/content/4/8/eaat6773

Abstract
Arctic Ocean measurements reveal a near doubling of ocean heat content relative to the freezing temperature in the Beaufort Gyre halocline over the past three decades (1987–2017). This warming is linked to anomalous solar heating of surface waters in the northern Chukchi Sea, a main entryway for halocline waters to join the interior Beaufort Gyre. Summer solar heat absorption by the surface waters has increased fivefold over the same time period, chiefly because of reduced sea ice coverage. It is shown that the solar heating, considered together with subduction rates of surface water in this region, is sufficient to account for the observed halocline warming. Heat absorption at the basin margins and its subsequent accumulation in the ocean interior, therefore, have consequences for Beaufort Gyre sea ice beyond the summer season.

&

Title: "Signs of Big Change in the Arctic - A once-predictable system shifts out of balance"

https://www.whoi.edu/oceanus/feature/signs-of-big-changes-in-the-arctic/

Extract: "For at least half a century and probably longer, the climate in the Arctic has run like a clock. As reliably as a pendulum, it has oscillated every five to seven years between two distinct self-regulating phases that shift the region’s winds, ice, currents, and other conditions.

But in a new study, scientists say the system has been stuck in one phase since 1997. The monkey wrench that’s jamming the works, they suspect, may be warming temperatures that are accelerating the melting of the Greenland Ice Sheet.

When ice melts, it can no longer play the important role of reflecting sunlight. Instead, the melting gives the sun unfettered access to the open water, allowing the ocean to absorb more heat.

As that heat diffuses upward over time, it stalls the growth of the sea ice during the winter in the region, said Toole. “And, if the deeper, warmer water starts mixing more vigorously with the cold water above it, we will see even more sea ice thinning during the summer.”"

&

Title: "A ‘Ticking Time Bomb’ in the Arctic - Waters are warming beneath the ocean's sea ice"

https://www.whoi.edu/oceanus/feature/a-ticking-time-bomb-in-the-arctic/

Extract: "When it comes to the ocean, deeper usually means colder. But there are exceptions. In the Arctic Ocean, for example, a warm layer of water is trapped 150 feet under the ocean’s chunky ice floes by a ceiling of cold fresh water near the surface. The cold layer insulates the sea ice from the warmer waters below.

In a 2018 study, scientists have found that the amount of heat in the trapped warm layer in the Beaufort Gyre, a major Arctic Ocean circulation system north of Alaska, has doubled over the past 30 years. And, if the temperatures continue to spike, it could eventually spell trouble for the ice above.

“At some point, the heat from this layer is going to have to come up to the surface, and it’s going to impact the ice,” said John Toole, a scientist at Woods Hole Oceanographic Institution (WHOI) and co-author of the study. “It’s a ticking time bomb.”

The study is yet another case in point of why melting Arctic sea ice is a problem: When ice melts, it can no longer play the important role of reflecting sunlight. Instead, the melting gives the sun unfettered access to the open water, allowing the ocean to absorb more heat.

As that heat diffuses upward over time, it stalls the growth of the sea ice during the winter in the region, said Toole. “And, if the deeper, warmer water starts mixing more vigorously with the cold water above it, we will see even more sea ice thinning during the summer.”"

Just is just a quick post to remind readers that Arctic Sea Ice contains a significant volume of freshwater, thus if the Beaufort Gyre were to release a significant pulse of its accumulated freshwater, that now only would the freshwater from the Beaufort Gyre advect to the North Atlantic but so would much of the volume of freshwater from the melted sea ice (due to the disruption of the halocline triggers by the Beaufort Gyre release).  Thus the combined volume of freshwater from the Beaufort Gyre and the associated melted sea ice would impact the AMOC, which would slow the MOC more than consensus climate scientist previously assumed.
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Re: Ice Apocalypse - MULTIPLE METERS SEA LEVEL RISE (narrated video)
« Reply #3167 on: May 12, 2020, 01:45:23 AM »
The linked reference discusses findings that increased Antarctic sea ice extent results in more CO2 being sequestered in the ocean, while when Antarctic sea ice extent decreases more CO2 leaves the ocean and enters the atmosphere.  Therefore, as global warming is projected to decrease Antarctic sea ice extent this implies that more CO2 will be emitted from the ocean in the coming decades.

Karl Stein el al., "Timing and magnitude of Southern Ocean sea ice/carbon cycle feedbacks," PNAS (2020).  https://doi.org/10.1073/pnas.1908670117

https://www.pnas.org/content/117/9/4498

Significance
Atmospheric carbon was sequestered in the ocean during glacial periods, but the processes responsible are not understood. Southern Ocean (SO) sea ice has been proposed as a link between several processes of carbon sequestration. This study analyzes the effect of SO sea ice on ocean ventilation in a 784,000-y climate model simulation. The results show that SO sea ice can dramatically reduce ocean ventilation by reducing the atmospheric exposure time of surface waters and by decreasing the vertical mixing of deep ocean waters. Sensitivity tests of the two mechanisms with a carbon cycle model show a 40-ppm reduction of atmospheric CO2, half the glacial/interglacial difference, with ocean stratification playing the leading role in both magnitude and timing.

Abstract
The Southern Ocean (SO) played a prominent role in the exchange of carbon between ocean and atmosphere on glacial timescales through its regulation of deep ocean ventilation. Previous studies indicated that SO sea ice could dynamically link several processes of carbon sequestration, but these studies relied on models with simplified ocean and sea ice dynamics or snapshot simulations with general circulation models. Here, we use a transient run of an intermediate complexity climate model, covering the past eight glacial cycles, to investigate the orbital-scale dynamics of deep ocean ventilation changes due to SO sea ice. Cold climates increase sea ice cover, sea ice export, and Antarctic Bottom Water formation, which are accompanied by increased SO upwelling, stronger poleward export of Circumpolar Deep Water, and a reduction of the atmospheric exposure time of surface waters by a factor of 10. Moreover, increased brine formation around Antarctica enhances deep ocean stratification, which could act to decrease vertical mixing by a factor of four compared with the current climate. Sensitivity tests with a steady-state carbon cycle model indicate that the two mechanisms combined can reduce atmospheric carbon by 40 ppm, with ocean stratification acting early within a glacial cycle to amplify the carbon cycle response.
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Re: Ice Apocalypse - MULTIPLE METERS SEA LEVEL RISE (narrated video)
« Reply #3168 on: May 12, 2020, 04:59:05 PM »
The linked reference used simulations from the Precipitation Driver and Response Model Intercomparison Project (PDRMIP); which included a lot of high-end ESMs that also participated in CMIP6; thus, their findings imply that the high-end simulations from CMIP6 (with typically high values of ECS) do a good job of matching historical records when using effective radiative forcing (ERF) for comparisons.  Unfortunately, AR5 and AR6 include a lot of low-end energy balance model simulations that use instantaneous radiative forcing which as the following quote indicates can result in efficacies that deviate considerably from unity; which can result in the calculation of low estimates of ECS (which are averaged together with more accurate estimates of ECS to result in a low bias for ECS in AR5 and likely in AR6).

"Efficacies calculated from instantaneous radiative forcing deviate considerably from unity across forcing agents and models. Effective radiative forcing (ERF) is a better predictor of global mean near‐surface air temperature (GSAT) change."

T. B. Richardson et al. (20 November 2019), "Efficacy of Climate Forcings in PDRMIP Models", JGR Atmospheres, https://doi.org/10.1029/2019JD030581

https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2019JD030581

Abstract
Quantifying the efficacy of different climate forcings is important for understanding the real‐world climate sensitivity. This study presents a systematic multimodel analysis of different climate driver efficacies using simulations from the Precipitation Driver and Response Model Intercomparison Project (PDRMIP). Efficacies calculated from instantaneous radiative forcing deviate considerably from unity across forcing agents and models. Effective radiative forcing (ERF) is a better predictor of global mean near‐surface air temperature (GSAT) change. Efficacies are closest to one when ERF is computed using fixed sea surface temperature experiments and adjusted for land surface temperature changes using radiative kernels. Multimodel mean efficacies based on ERF are close to one for global perturbations of methane, sulfate, black carbon, and insolation, but there is notable intermodel spread. We do not find robust evidence that the geographic location of sulfate aerosol affects its efficacy. GSAT is found to respond more slowly to aerosol forcing than CO2 in the early stages of simulations. Despite these differences, we find that there is no evidence for an efficacy effect on historical GSAT trend estimates based on simulations with an impulse response model, nor on the resulting estimates of climate sensitivity derived from the historical period. However, the considerable intermodel spread in the computed efficacies means that we cannot rule out an efficacy‐induced bias of ±0.4 K in equilibrium climate sensitivity to CO2 doubling when estimated using the historical GSAT trend.

Plain Language Summary
Does the climate respond in the same way to carbon dioxide as it does to methane or aerosol changes? The simple way of thinking about forcing and response in the Earth system assumes that it does, such that, a Watt per square meter forcing from CO2 has the same response as an equivalent forcing from aerosols. Recent work has suggested that this might not be true and that differences in how effective different forcings are at increasing surface temperature (their efficacy) may account for a low estimate of climate sensitivity when examining historical change. We show this all depends on how you estimate your Watts per meter squared forcing in the first place. Using the effective radiative forcing concept to estimate forcing strength makes temperature changes far more predictable, and a lot of these issues with efficacy variation are not as pronounced as they were with earlier definitions.
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Re: Ice Apocalypse - MULTIPLE METERS SEA LEVEL RISE (narrated video)
« Reply #3169 on: May 12, 2020, 06:05:40 PM »
Kate Marvel has spent most of her career studying cloud feedback (which has proven to be key w.r.t. the high values of ECS projected by the high-end CMIP6 model projections) and in the linked opinion piece she acknowledges a good amount of uncertainty about projections of future climate change; which from a risk point of view is not good:

Title: "Global Warming: How Hot, Exactly, Is it Going to Get?"

https://blogs.scientificamerican.com/hot-planet/global-warming-how-hot-exactly-is-it-going-to-get/

Extract: "All climate models simulate a changing planet in response to a changing temperature. And, increasingly, we know why they disagree on that final warming. In the climate models that warm more, low, thick clouds appear to be changing in ways that reduce their sun-blocking power. In the models that warm less, these changes are smaller.

So scientists have devoted their time to measuring clouds, understanding them, and figuring out how to represent them in climate models. This work has paid off: the range of uncertainty is now changing. Unfortunately, it’s increased. Climate models that use more modern techniques to simulate clouds are now projecting more warming: five or six degrees Celsius in response to a doubling of carbon dioxide. To put those numbers in context, four and a half degrees is the difference between now and the last Ice Age.

But the past is not the future, and we have good reason to believe that there are no analogues for the future into which we are hurtling."
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Re: Ice Apocalypse - MULTIPLE METERS SEA LEVEL RISE (narrated video)
« Reply #3170 on: May 13, 2020, 03:21:03 PM »
While I have frequently posted to cite evidence that climate sensitivity (including ice-climate feedback mechanisms and freshwater hosing events) is probably higher that assumed by consensus climate science; while the linked post reminds us that climate impacts will likely be higher than currently assumed by documents like AR5; which means that climate risk (probability times impact) is likely considerably higher than currently acknowledged by consensus climate science:

Kai Kornhuber et al (2019), "Extreme weather events in early summer 2018 connected by a recurrent hemispheric wave-7 pattern", Environ. Res. Lett. Vol.14, No. 054002, https://doi.org/10.1088/1748-9326/ab13bf

https://iopscience.iop.org/article/10.1088/1748-9326/ab13bf
https://iopscience.iop.org/article/10.1088/1748-9326/ab13bf/pdf

Abstract
The summer of 2018 witnessed a number of extreme weather events such as heatwaves in North America, Western Europe and the Caspian Sea region, and rainfall extremes in South-East Europe and Japan that occurred near-simultaneously. Here we show that some of these extremes were connected by an amplified hemisphere-wide wavenumber 7 circulation pattern. We show that this pattern constitutes an important teleconnection in Northern Hemisphere summer associated with prolonged and above-normal temperatures in North America, Western Europe and the Caspian Sea region. This pattern was also observed during the European heatwaves of 2003, 2006 and 2015 among others. We show that the occurrence of this wave 7 pattern has increased over recent decades.

See also:

Title: "Newly Identified Jet-Stream Pattern Could Imperil Global Food Supplies"

https://blogs.scientificamerican.com/eye-of-the-storm/newly-identified-jet-stream-pattern-could-imperil-global-food-supplies/

Extract: "A new study finds a 20-fold increase in the risk of simultaneous heat waves in major crop-producing regions when the pattern is in place.

Unfortunately, extreme jet stream patterns like those of 2018 may be getting more common and more extreme, representing a significant danger to global food security. An April 26 paper, Extreme weather events in early summer 2018 connected by a recurrent hemispheric wave-7 pattern, by climate scientist Kai Kornhuber of Columbia University and co-authors, found that the 2018 extremes were associated with a particular mode of “stuck in place” jet stream behavior—one that has increased in frequency and persistence in recent decades."

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Re: Ice Apocalypse - MULTIPLE METERS SEA LEVEL RISE (narrated video)
« Reply #3171 on: May 13, 2020, 03:32:52 PM »
The linked article cites research findings into extreme atmospheric and climate events and demonstrates unambiguously that abrupt transitions to the Earth's equatorial superrotation is possible (with continued climate change) due to a feedback mechanism between equatorial atmospheric waves and the background wind (with the currently prevail equatorial easterlies abruptly transitioning to prevailing westerlies [the characterize El Nino events]).

Title: "Understanding Extreme Events in Turbulent Flows"

https://cordis.europa.eu/article/id/415960-understanding-the-extreme-events-in-turbulent-flows

Extract: "The scientific aim of the project was to investigate whether spontaneous transitions between bi-stable states existed at all in the atmosphere and whether they were like noise-induced transitions studied in statistical physics. “Although it is impossible to know when the transition will happen, the dynamics are generally predictable as the system always follows the same path to produce the rare event,” explains Herbert.

The phenomenon the project focused on, called equatorial superrotation, is a reversal in the direction of tropical surface winds.

“While easterlies prevail on Earth, westerlies are observed on many planetary atmospheres like Venus,” says Herbert. “Abrupt transitions to superrotation might provide a new example of a tipping point for global climate, or more speculatively, for anthropogenic climate change.”

Using theoretical computations and numerical simulations, the project has unambiguously shown that a feedback mechanism between equatorial waves in the atmosphere and the background wind lead to bi-stability and abrupt transitions. The project also clarified under which conditions this happens."
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Re: Ice Apocalypse - MULTIPLE METERS SEA LEVEL RISE (narrated video)
« Reply #3172 on: May 14, 2020, 02:05:50 AM »
The research cited in the linked article finds that '… even the smallest changes in atmospheric conditions could trigger a hurricane …'.  Thus imagine what future storms that climate change can trigger:

Title: "Researchers find even small disturbances can trigger catastrophic storms"

https://phys.org/news/2020-05-small-disturbances-trigger-catastrophic-storms.html

Extract: "After decades of research, meteorologists still have questions about how hurricanes develop. Now, Florida State University researchers have found that even the smallest changes in atmospheric conditions could trigger a hurricane, information that will help scientists understand the processes that lead to these devastating storms."
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Re: Ice Apocalypse - MULTIPLE METERS SEA LEVEL RISE (narrated video)
« Reply #3173 on: May 14, 2020, 04:01:08 PM »
The linked associated articles suggest that the co-evolution of technological promises modeling have contributed to over three decades of irrational decision making on climate change policy.

McLaren, D., Markusson, N. The co-evolution of technological promises, modelling, policies and climate change targets. Nat. Clim. Chang. 10, 392–397 (2020). https://doi.org/10.1038/s41558-020-0740-1

https://www.nature.com/articles/s41558-020-0740-1

Abstract
The nature and framing of climate targets in international politics has changed substantially since their early expressions in the 1980s. Here, we describe their evolution in five phases—from ‘climate stabilization’ to specific ‘temperature outcomes’—co-evolving with wider climate politics and policy, modelling methods and scenarios, and technological promises (from nuclear power to carbon removal). We argue that this co-evolution has enabled policy prevarication, leaving mitigation poorly delivered, yet the technological promises often remain buried in the models used to inform policy. We conclude with a call to recognise and break this pattern to unleash more effective and just climate policy.

See also:

Title: "Guest post: A brief history of climate targets and technological promises"

https://www.carbonbrief.org/guest-post-a-brief-history-of-climate-targets-and-technological-promises

Extract: "Over the past three decades, the perceived wisdom for how to approach climate targets has changed several times.

… my research into this history, published in Nature Climate Change with my coauthor Dr Nils Markusson and part of a project examining the cultural political economy of carbon removal, suggests that the process has been much less rational – and more problematic – than this explanation might imply.

In particular, our analysis highlights that each shift in target framing has opened the door to new hopes of future technological solutions, such as widespread nuclear power or carbon capture and storage. Yet, while these technologies have promised much, as promises they have instead delayed the immediate acceleration of action to change behaviours or transform economies.

First, merely adding new technologies is unlikely to bring the climate challenge under control, unless we also deliver behavioural, cultural and economic transformations.

Second, technological promises allow those benefiting from the continued exploitation of fossil fuels and the comfortable lifestyles it enables to justify those practices to themselves. This allows their activities to impose ever greater burdens and risks on those most vulnerable to climate change – today’s poor and future generations."
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Re: Ice Apocalypse - MULTIPLE METERS SEA LEVEL RISE (narrated video)
« Reply #3174 on: May 14, 2020, 04:59:11 PM »
The linked associated articles suggest that the co-evolution of technological promises modeling have contributed to over three decades of irrational decision making on climate change policy.

McLaren, D., Markusson, N. The co-evolution of technological promises, modelling, policies and climate change targets. Nat. Clim. Chang. 10, 392–397 (2020). https://doi.org/10.1038/s41558-020-0740-1

https://www.nature.com/articles/s41558-020-0740-1
...

Probably the biggest problem with taking effective global socio-economic action to deal with climate change.
« Last Edit: May 15, 2020, 03:37:38 PM by AbruptSLR »
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Re: Ice Apocalypse - MULTIPLE METERS SEA LEVEL RISE (narrated video)
« Reply #3175 on: May 15, 2020, 02:59:58 AM »
For anyone who doesn't know, beef is the worst food that one can eat w.r.t. accelerating climate change.

Title: "The food to avoid if you care about climate change"

https://www.vox.com/videos/2020/5/14/21257118/food-avoid-climate-change-emissions-beef

Extract: "But it doesn’t explain everything — the farming process for some foods, like coffee, uses fertilizers that emit the powerful greenhouse gas, nitrous oxide. And the biology of some animals, known as ruminants, is responsible for emitting tons of methane into the atmosphere."

Edit: There is little Americans won't sacrifice for a steak, sad but true.

Title: "How Cheap Meat Became an “Essential” American Value"

https://slate.com/human-interest/2020/05/meat-production-essential-american-value-coronavirus.html

Extract: "Keeping meat production moving during the pandemic is dangerous. But history shows that there’s little Americans won’t sacrifice for a steak."
« Last Edit: May 15, 2020, 03:12:52 AM by AbruptSLR »
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Re: Ice Apocalypse - MULTIPLE METERS SEA LEVEL RISE (narrated video)
« Reply #3176 on: May 15, 2020, 03:23:30 AM »
People's brains are making it hard to solve climate change.

Title: "How our brains make it hard to solve climate change"

https://www.washingtonpost.com/climate-solutions/2020/05/14/how-our-brains-make-it-hard-solve-climate-change/

Extract: "Shahzeen Attari, 38, is an associate professor at the School of Public and Environmental Affairs at Indiana University. She’s particularly focused on the way people perceive their personal energy use and the decisions they make in their daily lives, and how that impacts greenhouse gas emissions linked to a warming planet.

She published a paper earlier this year that examined how people understand the energy system in the United States and what they hoped it would look like in 2050. She and her team of researchers found that both liberals and conservatives expect the energy system of the future will be dominated by renewable sources, such as solar and wind."

See also:

Deidra Miniard, Joseph Kantenbacher, and Shahzeen Z. Attari (March 31, 2020), "Shared vision for a decarbonized future energy system in the United States", PNAS, 117, (13), 7108-7114; https://doi.org/10.1073/pnas.1920558117

https://www.pnas.org/content/117/13/7108

Significance
We explore public perceptions of the current and future energy mixes in the United States. Participants tend to underestimate contributions of oil and natural gas (although coal does not match this pattern) and overestimate contributions of solar and wind to the current national energy mix, problematically misperceiving that the current mix is more decarbonized than it really is. Both conservatives and liberals want a decarbonized future energy mix for 2050—a significant decrease in fossil fuel use and a significant increase in solar and wind energy. Although there is a shared vision of a decarbonized future energy mix, there are strong differences between liberal and conservative participants in their support for policies to achieve this future.

Abstract
How do people envision the future energy system in the United States with respect to using fossil fuels, renewable energy, and nuclear energy? Are there shared policy pathways of achieving a decarbonized energy system? Here, we present results of an online survey (n = 2,429) designed to understand public perceptions of the current and future energy mixes in the United States (i.e., energy sources used for electric power, transportation, industrial, commercial, and residential sectors). We investigate support for decarbonization policies and antidecarbonization policies and the relative importance of climate change as an issue. Surprisingly, we find bipartisan support for a decarbonized energy future. Although there is a shared vision for decarbonization, there are strong partisan differences regarding the policy pathways for getting there. On average, our participants think that climate change is not the most important problem facing the United States today, but they do view climate change as an important issue for the world today and for the United States and the world in the future.
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AbruptSLR

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Re: Ice Apocalypse - MULTIPLE METERS SEA LEVEL RISE (narrated video)
« Reply #3177 on: May 15, 2020, 04:11:28 AM »
The linked article cites consensus climate science values and still calculates a 13% chance of human extinction before 2100:

Title: "Author C.S Goldsmith Weighs in on The Climate Crisis and the Crucial Decade Ahead"

https://www.prweb.com/releases/author_c_s_goldsmith_weighs_in_on_the_climate_crisis_and_the_crucial_decade_ahead/prweb17058095.htm

Extract: "According to Mathematicians from the University of Barcelona, there is a 13 % chance that we too will become extinct before the end of this century."

« Last Edit: May 15, 2020, 03:34:39 PM by AbruptSLR »
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Re: Ice Apocalypse - MULTIPLE METERS SEA LEVEL RISE (narrated video)
« Reply #3178 on: May 15, 2020, 04:25:00 AM »
Anyone who thinks that mankind is going to do well with major ecosystems collapsing around us all, is kidding themselves:

Title: "Climate tipping point ecosystem collapses may come faster than thought: Studies"

https://news.mongabay.com/2020/05/climate-tipping-point-ecosystem-collapses-may-come-faster-than-thought-studies/

Extract: "Two recent studies shine a light on a relatively new field of study: the means by which climate tipping points can lead to ecosystem collapse, and how quickly such crashes might occur.

The first study modeled a database of aquatic and terrestrial ecosystems and found that large ecosystems, while seeming more stable, can collapse disproportionately faster than small ones due to a domino effect by which interrelated habitats and species within a system can impact each other, causing a rapid cascading collapse.

Some scientists praised the study for being pathfinding, while others faulted it for looking at too few ecosystems, and then making overlarge generalizations about the crashing of large systems, like the Amazon rainforest, a biome which was not included in the study database.

A second study found that even small changes in an ecosystem can, via evolution, ripple outward, creating bigger and bigger alterations leading eventually to a system collapse. Scientists agree that much more research will be needed to refine collapse forecasts.
"

See also:

Cooper, G.S., Willcock, S. & Dearing, J.A. Regime shifts occur disproportionately faster in larger ecosystems. Nat Commun 11, 1175 (2020).

Chaparro-Pedraza, P.C., de Roos, A.M. Ecological changes with minor effect initiate evolution to delayed regime shifts. Nat Ecol Evol 4, 412–418 (2020).
« Last Edit: May 15, 2020, 03:33:59 PM by AbruptSLR »
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Re: Ice Apocalypse - MULTIPLE METERS SEA LEVEL RISE (narrated video)
« Reply #3179 on: May 15, 2020, 04:58:32 AM »
Thanks a bunch AbruptSLR for these postings and for your stance. Both are much appreciated.
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Re: Ice Apocalypse - MULTIPLE METERS SEA LEVEL RISE (narrated video)
« Reply #3180 on: May 15, 2020, 11:22:36 AM »
Thanks a bunch AbruptSLR for these postings and for your stance. Both are much appreciated.
I agree wholeheartedly.
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Re: Ice Apocalypse - MULTIPLE METERS SEA LEVEL RISE (narrated video)
« Reply #3181 on: May 15, 2020, 11:07:19 PM »
NOAA has now updated their Annual Greenhouse Gas Index (AGGI) and associated annual CO2-equivalent values through the end of 2019 (see the attached image).  They calculate a value of 500ppm for CO2-eq, however, NOAA uses a GWP-100 value of 28 to calculate this value; which means that this 500ppm value likely errs on the side of least drama.

Title: "NOAA's Annual Greenhouse Gas Index"

https://www.esrl.noaa.gov/gmd/aggi/
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Re: Ice Apocalypse - MULTIPLE METERS SEA LEVEL RISE (narrated video)
« Reply #3182 on: May 15, 2020, 11:10:02 PM »
Thanks a bunch AbruptSLR for these postings and for your stance. Both are much appreciated.
I agree wholeheartedly.

Thank you both, and thank you to future generations who willingly, or unwillingly, will be inheriting the world that we leave for them in the coming decades.
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Re: Ice Apocalypse - MULTIPLE METERS SEA LEVEL RISE (narrated video)
« Reply #3183 on: May 15, 2020, 11:49:04 PM »
Might not be the coming decade.
Might be coming years... or past years.
SHARKS (CROSSED OUT) MONGEESE (SIC) WITH FRICKIN LASER BEAMS ATTACHED TO THEIR HEADS

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Re: Ice Apocalypse - MULTIPLE METERS SEA LEVEL RISE (narrated video)
« Reply #3184 on: May 16, 2020, 12:22:28 AM »
The linked reference uses a combination of paleodata and climate modeling to verify that Arctic Amplification in raising the Holocene thermal maximum GMSTA above that for preindustrial.  This suggests that Arctic Amplification will play an important role in future global warming:

Hyo-Seok Park et al. (11 Dec 2019), "Mid-Holocene Northern Hemisphere warming driven by Arctic amplification", Science Advances, Vol. 5, no. 12, eaax8203, DOI: 10.1126/sciadv.aax8203

https://advances.sciencemag.org/content/5/12/eaax8203

Abstract
The Holocene thermal maximum was characterized by strong summer solar heating that substantially increased the summertime temperature relative to preindustrial climate. However, the summer warming was compensated by weaker winter insolation, and the annual mean temperature of the Holocene thermal maximum remains ambiguous. Using multimodel mid-Holocene simulations, we show that the annual mean Northern Hemisphere temperature is strongly correlated with the degree of Arctic amplification and sea ice loss. Additional model experiments show that the summer Arctic sea ice loss persists into winter and increases the mid- and high-latitude temperatures. These results are evaluated against four proxy datasets to verify that the annual mean northern high-latitude temperature during the mid-Holocene was warmer than the preindustrial climate, because of the seasonally rectified temperature increase driven by the Arctic amplification. This study offers a resolution to the “Holocene temperature conundrum”, a well-known discrepancy between paleo-proxies and climate model simulations of Holocene thermal maximum.
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Re: Ice Apocalypse - MULTIPLE METERS SEA LEVEL RISE (narrated video)
« Reply #3185 on: May 16, 2020, 12:27:51 AM »
This is a reminder that the linked reference indicates that ozone-depleting substances, ODSs, likely have contributed to up to half of the observed Arctic Amplification in recent decades.

Polvani, L.M., Previdi, M., England, M.R. et al. Substantial twentieth-century Arctic warming caused by ozone-depleting substances. Nat. Clim. Chang. 10, 130–133 (2020). https://doi.org/10.1038/s41558-019-0677-4

https://www.nature.com/articles/s41558-019-0677-4

Abstract
The rapid warming of the Arctic, perhaps the most striking evidence of climate change, is believed to have arisen from increases in atmospheric concentrations of GHGs since the Industrial Revolution. While the dominant role of carbon dioxide is undisputed, another important set of anthropogenic GHGs was also being emitted over the second half of the twentieth century: ozone-depleting substances (ODS). These compounds, in addition to causing the ozone hole over Antarctica, have long been recognized as powerful GHGs. However, their contribution to Arctic warming has not been quantified. We do so here by analysing ensembles of climate model integrations specifically designed for this purpose, spanning the period 1955–2005 when atmospheric concentrations of ODS increased rapidly. We show that, when ODS are kept fixed, forced Arctic surface warming and forced sea-ice loss are only half as large as when ODS are allowed to increase. We also demonstrate that the large impact of ODS on the Arctic occurs primarily via direct radiative warming, not via ozone depletion. Our findings reveal a substantial contribution of ODS to recent Arctic warming, and highlight the importance of the Montreal Protocol as a major climate change-mitigation treaty.
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Re: Ice Apocalypse - MULTIPLE METERS SEA LEVEL RISE (narrated video)
« Reply #3186 on: May 16, 2020, 12:50:45 PM »
As I said that I would make a few posts (which I take to mean three posts today), I provide the following like to an article that cites research that confirms that current ice mass loss is contributing (see blue line in the attached image) to the drift of the Earth's rotational axis about the poles:

Scientists Identified Three Reasons Responsible for Earth’s Spin Axis Drift

http://www.geologyin.com/2018/09/scientists-identified-three-reasons.html

Extract: "A typical desk globe is designed to be a geometric sphere and to rotate smoothly when you spin it. Our actual planet is far less perfect—in both shape and in rotation.

Earth is not a perfect sphere. When it rotates on its spin axis—an imaginary line that passes through the North and South Poles—it drifts and wobbles. These spin-axis movements are scientifically referred to as "polar motion." Measurements for the 20th century show that the spin axis drifted about 4 inches (10 centimeters) per year. Over the course of a century, that becomes more than 11 yards (10 meters).

Using observational and model-based data spanning the entire 20th century, NASA scientists have for the first time identified three broadly-categorized processes responsible for this drift—contemporary mass loss primarily in Greenland, glacial rebound, and mantle convection.

"The traditional explanation is that one process, glacial rebound, is responsible for this motion of Earth's spin axis. But recently, many researchers have speculated that other processes could have potentially large effects on it as well," said first author Surendra Adhikari of NASA's Jet Propulsion Laboratory in Pasadena, California."

The Magnetic North Pole is continuing to move rapidly towards Siberia as documented by the linked reference and associated article:

Livermore, P.W., Finlay, C.C. & Bayliff, M. Recent north magnetic pole acceleration towards Siberia caused by flux lobe elongation. Nat. Geosci. 13, 387–391 (2020). https://doi.org/10.1038/s41561-020-0570-9

https://www.nature.com/articles/s41561-020-0570-9.epdf?sharing_token=S9rGiu_2ZWLFbRUwPa8CYNRgN0jAjWel9jnR3ZoTv0NKkhOOgKzOVqiZYU4nlxXxWIa8QRdBhLYpnuGEXoit2P7MvnZRdEETQKcjQOtHKEGbVr0HBkTMUJCPbHzXVqdGRseQatIZjoo5TaAXKYfJsvnWmrzbh0P3Z0S6Ihgc1KsAUXDXxM0QUQPH320GwUJpm7eJLJnGVneOESP2IhwEILjI_9NwV864lOJS_LlnuHUrKGsvkXxhn0eiW4dbn8_zMAxgE-068GUXg50Q8Osj-w==&tracking_referrer=www.livescience.com
or
https://www.nature.com/articles/s41561-020-0570-9

Abstract: "The wandering of Earth’s north magnetic pole, the location where the magnetic field points vertically downwards, has long been a topic of scientific fascination. Since the first in-situ measurements in 1831 of its location in the Canadian arctic, the pole has drifted inexorably towards Siberia, accelerating between 1990 and 2005 from its historic speed of 0–15 km yr−1 to its present speed of 50–60 km yr−1. In late October 2017 the north magnetic pole crossed the international date line, passing within 390 km of the geographic pole, and is now moving southwards. Here we show that over the last two decades the position of the north magnetic pole has been largely determined by two large-scale lobes of negative magnetic flux on the core–mantle boundary under Canada and Siberia. Localized modelling shows that elongation of the Canadian lobe, probably caused by an alteration in the pattern of core flow between 1970 and 1999, substantially weakened its signature on Earth’s surface, causing the pole to accelerate towards Siberia. A range of simple models that capture this process indicate that over the next decade the north magnetic pole will continue on its current trajectory, travelling a further 390–660 km towards Siberia."

See also:

Title: "The Magnetic North Pole Is Rapidly Moving Because of Some Blobs"

https://www.popularmechanics.com/science/environment/a32496561/why-magnetic-north-pole-moving/

Extract: "In 2017, the magnetic north pole fell within 240 miles of the geographic north pole. The movement has been so rapid that the British Geological Survey and U.S. National Geophysical Data Center, which update the World's Magnetic Model, had to accelerate their process in order to keep up.

The scientists generated a series of models of Earth's core in an effort to understand how it might move in the future. "Our predictions are that the pole will continue to move towards Siberia, but forecasting the future is challenging and we cannot be sure," the study's lead author, geophysicist Phil Livermore of the University of Leeds, told Live Science."
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Tom_Mazanec

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Re: Ice Apocalypse - MULTIPLE METERS SEA LEVEL RISE (narrated video)
« Reply #3187 on: May 16, 2020, 02:27:40 PM »
Maybe this is a sign of a geomagnetic reversal this millennium?
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Re: Ice Apocalypse - MULTIPLE METERS SEA LEVEL RISE (narrated video)
« Reply #3188 on: May 16, 2020, 10:23:58 PM »
Maybe this is a sign of a geomagnetic reversal this millennium?

Per the first linked article, in extreme cases, magnetic pole reversals took less than 100 years and per the second linked article true polar wander can trigger can ice sheet formation; thus it is logical that the abrupt loss of an ice sheet like the WAIS might possibly trigger a magnetic pole reversal this century (in an extreme case):

Title: "Shifting Magnetic North may be caught in 'tug of war' between Canada and Siberia"

https://www.theweathernetwork.com/ca/news/article/shifting-magnetic-north-pole-caught-in-tug-of-war-between-canada-siberia-blobs

Extract: "Based on the width of the sea-floor bands, in extreme cases, some pole reversals took less than 100 years. Some lasted only around 200 years before they flipped back.

&

Title: "'True polar wander' may have caused ice age"

https://www.sciencedaily.com/releases/2018/11/181119160239.htm

Extract: "Like any spinning object, Earth is subject to centrifugal force, which tugs on the planet's fluid interior. At the equator, where this force is strongest, Earth is more than 26 miles larger in diameter than at the poles. Gordon said true polar wander may occur when dense, highly viscous bumps of mantle build up at latitudes away from the equator."

If the mantle anomalies are massive enough, they can unbalance the planet, and the equator will gradually shift to bring the excess mass closer to the equator. The planet still spins once every 24 hours and true polar wander does not affect the tilt of the Earth's spin axis relative to the sun. The redistribution of mass to a new equator does change Earth's poles, the points on the planet's surface where the spin axis emerges.

Woodworth said the hot spot data from Hawaii provides some of the best evidence that true polar wander was what caused Earth's poles to start moving 12 million years ago. Islands chains like the Hawaiians are formed when a tectonic plate moves across a hot spot."

Edit, see also:

Daniel Woodworth, Richard G. Gordon. Paleolatitude of the Hawaiian Hot Spot Since 48 Ma: Evidence for a Mid-Cenozoic True Polar Stillstand Followed by Late Cenozoic True Polar Wander Coincident With Northern Hemisphere Glaciation. Geophysical Research Letters, 2018; DOI: 10.1029/2018GL080787

https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2018GL080787

Abstract
Paleospin axis locations since 48 Ma inferred from the distribution of equatorial sediment accumulation rates on the Pacific plate, together with paleomagnetic poles from magnetic anomaly skewness, indicate that the Hawaiian hot spot was nearly fixed in latitude from 48 to 12 Ma, but ≈3° north of its current latitude. From 48 to 12 Ma in the Pacific hot spot reference frame, which we take to be equivalent to the global hot spot reference frame, the spin axis was located near 87°N, 164°E, recording a stillstand in true polar wander. Global hot spots shifted coherently relative to the spin axis since ≈12 Ma, consistent with an episode of true polar wander, which may continue today. The motion of the spin axis away from the Hawaiian hot spot and toward Greenland since ≈12 Ma coincided with, and may have contributed to, the onset of northern hemisphere glaciation.

Plain Language Summary
The Earth has shifted relative to its spin axis over the past 12 million years (Ma). This shift, which geoscientists call true polar wander, caused the Earth's mantle beneath the tropical Pacific to move southward while causing Greenland to move northward. The latter motion may have contributed to the onset of the current ice age, which began ≈3 Ma before present. These conclusions follow our analysis of the history of motion of the Pacific tectonic plate relative to the spin axis, which is preserved in sediments and rocks on the Pacific seafloor. We also infer the motion of the Pacific plate relative to the solid Earth from the plate's history of motion relative to hot spots, such as Hawaii. Hot spots are sites of voluminous volcanism, thought to lie over rising plumes of hot rock from deep in the Earth's mantle. As the Pacific plate moves over the Hawaiian plume, it creates a line of extinct volcanoes that record the motion of the plate relative to the plume. Combining this information, we find that Hawaii and other global hot spots were nearly fixed in latitude from 48 to 12 Ma before present, which marks a 36‐Ma‐long time interval preceding the shift.

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Re: Ice Apocalypse - MULTIPLE METERS SEA LEVEL RISE (narrated video)
« Reply #3189 on: May 16, 2020, 10:36:09 PM »
The first linked reference (& associated article & image) indicate that the Erta 'Ale volcano in Ethiopia has been unusually active recently and is continuing to discharge magma.  Could abrupt SLR this century trigger still more magmatism, and if so could such magmatism trigger a polar wander event?

C. Moore, T. Wright, A. Hooper and J. Biggs (23 November 2019), "The 2017 Eruption of Erta 'Ale Volcano, Ethiopia: Insights Into the Shallow Axial Plumbing System of an Incipient Mid‐Ocean Ridge", Geochemistry, Geophysics, Geosystems,
 
https://doi.org/10.1029/2019GC008692

https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2019GC008692

Abstract: "The final stage of continental breakup is often accompanied by abundant magmatism. Erta 'Ale volcano lies on the Nubia‐Arabia extensional boundary in Afar, Ethiopia, an incipient mid‐ocean ridge. A fissure on the south flank of Erta 'Ale began erupting on 21 January 2017 and has remained active until at least July 2019. We use Sentinel‐1 synthetic aperture radar acquisitions to create a time series of ground displacement measurements at Erta 'Ale from October 2014 to June 2019, covering the eruption and its buildup. In the preeruption period, we observe gradual extension centered on the lava lake, consistent with the opening of an axis‐aligned dike. Using synthetic aperture radar intensity shadows, we show that the long‐lived Erta 'Ale lava lake was stable in this period, indicative of a steady pressure state in the shallow plumbing system. During the initial eruption, we observe surface displacements consistent with a shallow dike intrusion below the eruption site and conduit contraction below the lava lake. The pressure change associated with the cointrusive drop in the lava lake level is sufficient to reproduce the deformation pattern suggesting that the lava lake is well connected to the shallow plumbing system. Subsidence and contraction during the long‐lived eruption indicates the presence of an off‐rift vertically extensive source. We suggest that this may represent a system of stacked sources throughout the upper crust, with melt being more distributed. We also propose that high magma flux on the slow‐spreading Erta 'Ale segment may be facilitating the presence of shallow axial magma bodies."

&

Title: "Are We Seeing a New Ocean Starting to Form in Africa?"

https://eos.org/articles/are-we-seeing-a-new-ocean-starting-to-form-in-africa?utm_source=eos&utm_medium=email&utm_campaign=EosBuzz051420


Extract: "The entire Afar region in eastern Africa finds itself in the middle of changes that could split the continent, forming a new ocean basin. The magmatism at Erta Ale might be offering signs of this switch by mimicking the characteristics of a mid-ocean ridge.

The eruption at Erta Ale continues today. Moore’s research has shown that the volcano’s magmatic plumbing is a close continental analogue to the mid-ocean ridge magmatism in the East Pacific Rise. The question remains whether that similarity is a sign of things to come."

Caption: "These maps show (left to right) the location of Erta Ale in the Afar region of eastern Africa and the thermal signature of its lava lakes, and the eruption from 2017 to the present. Abbreviations are EAVS, Erta Ale volcanic segment; TAVS, Tat Ale volcanic segment; AFVS, Afdera volcanic segment; ALVS, Alayta volcanic segment; DVS, Dabbahu volcanic segment; RSR, Red Sea Rift; GAR, Gulf of Aden Rift; and MER, Main Ethiopian Rift. Credit: Moore et al., 2019, https://doi.org/10.1029/2019GC008692"

See also:

Muttoni, G., & Kent, D. V. [2019]. Jurassic monster polar shift confirmed by sequential paleopoles from Adria, promontory of Africa. Journal of Geophysical Research: Solid Earth, 124. https://doi.org/10.1029/2018JB017199

https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2018JB017199

Abstract: "Jurassic paleomagnetic data from North America have long been contentious, generating ambiguities in the shape of the global‐composite apparent polar wander path. Here we show from a restudy of two subdivisions of the Late Jurassic Morrison Formation at the classic locality at Norwood on the Colorado Plateau that the derived paleopoles reflect variable overprinting probably in the Cretaceous and are of limited value for apparent polar wander determination. We instead assembled an updated set of Jurassic paleopoles from parauthocthonous Adria, the African promontory, using primary paleomagnetic component directions derived from stratigraphically superposed intervals and corrected for sedimentary inclination error. These paleopoles are found to be in superb agreement with independent igneous paleopoles from the literature across the so‐called Jurassic monster polar shift, which in North American coordinates is a jump of ~30° arc distance from the 190‐ to 160‐Ma stillstand pole at 79.5°N 104.8°E to a 148 ± 3.5‐Ma pole at 60.8°N 200.6°E defined by four Adria sedimentary paleopoles and the published Ithaca, Hinlopenstretet, and Swartsruggens‐Bumbeni igneous paleopoles. The implied high rate of polar motion of ~2.5°/Myr across the monster shift is compatible with maximum theoretical estimates for true polar wander. We include a critique of published Jurassic paleomagnetic data that have been variably used in reference APWPs but that as a result of their low quality muted the real magnitude of the Jurassic monster shift. Finally, we provide paleocontinental reconstructions to describe examples of the bold signature that the monster polar shift left in the distribution of climate‐sensitive sedimentary facies worldwide."
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Re: Ice Apocalypse - MULTIPLE METERS SEA LEVEL RISE (narrated video)
« Reply #3190 on: May 16, 2020, 10:49:12 PM »
The linked reference (& associated article and images) show that while the paleo marine portions of the Fennoscandian Ice Sheet and the Antarctic Ice Sheets made abrupt contributions to SLR during Melt Water Pulse 1a (MWP 1a) that the Younger Dryas event (circa 13kya to 11.5kya) may have been triggered by a MISI-type of collapse of part of the paleo Cordilleran Ice Sheet.  To me this added support to the idea that an abrupt collapse of major portions of the WAIS, and/or an abrupt freshwater hosing event from the Beaufort Gyre, could trigger rapid climate change this century:

T. Pico et al. Sea level fingerprinting of the Bering Strait flooding history detects the source of the Younger Dryas climate event, Science Advances (2020). DOI: 10.1126/sciadv.aay2935

https://advances.sciencemag.org/content/6/9/eaay2935

Abstract
During the Last Glacial Maximum, expansive continental ice sheets lowered globally averaged sea level ~130 m, exposing a land bridge at the Bering Strait. During the subsequent deglaciation, sea level rose rapidly and ultimately flooded the Bering Strait, linking the Arctic and Pacific Oceans. Observational records of the Bering Strait flooding have suggested two apparently contradictory scenarios for the timing of the reconnection. We reconcile these enigmatic datasets using gravitationally self-consistent sea-level simulations that vary the timing and geometry of ice retreat between the Laurentide and Cordilleran Ice Sheets to the southwest of the Bering Strait to fit observations of a two-phased flooding history. Assuming the datasets are robust, we demonstrate that their reconciliation requires a substantial melting of the Cordilleran and western Laurentide Ice Sheet from 13,000 to 11,500 years ago. This timing provides a freshwater source for the widely debated Younger Dryas cold episode (12,900 to 11,700 years ago).

Extract: "We refine the timing and geometry of relative sea level change in the Bering Strait during the last deglaciation by constructing an ice history within the CIS and western LIS that is consistent with available land dates. Our ice sheet reconstructions, which maintain fits to sea level records in the far-field (section S9), yield sea level predictions that reconcile disparate and previously enigmatic datasets recording the inundation history of the Bering Shelf. Our inferred ice-melting scenarios source substantial meltwater from the retreat between the CIS and LIS from 13 to 11.5 ka ago in the region west of 110°W, potentially initiated by marine retreat of the ice sheet (fig. S16). Part of the freshwater flux from this ice-mass loss (0.11 Sv over the period 13 to 11.5 ka ago) would have freshened the subpolar North Atlantic and may have been sufficient to suppress deepwater convection and thereby initiate Younger Dryas cooling (30–32). The end of the meltwater flux may have also had a role in terminating the anomalous Younger Dryas cooling and triggering the onset of early Holocene warmth."

Caption for the first image: "Fig. 3 Eustatic contributions of each ice sheet.
Cordilleran and western Laurentide Ice Sheet (CIS) in black, Laurentide Ice Sheet (east of 110°W; LIS) in gray, Fennoscandian Ice Sheet (FIS) in blue, and Antarctic Ice Sheet (AIS) in red, for both ICE-6G (solid) and an alternate ice model, GI-31 (dashed). The shaded gray rectangle highlights the interval of 13 to 11.5 ka. The Younger Dryas (YD; 12.9 to 11.7 ka) and Meltwater Pulse-1a (MWP-1a; 14.5 to 14 ka ago) are labeled. The inset compares total global eustatic histories for ICE-6G (gray) and GI-31 (pink), which differ by less than 2 m from 13 to 11.5 ka ago."

&

Supplementary Materials for Sea level fingerprinting of the Bering Strait flooding history detects the source of the Younger Dryas climate event T. Pico, J. X. Mitrovica, A. C. Mix

https://advances.sciencemag.org/content/suppl/2020/02/24/6.9.eaay2935.DC1
https://advances.sciencemag.org/content/advances/suppl/2020/02/24/6.9.eaay2935.DC1/aay2935_SM.pdf

Caption for the second image: "Fig. S17. Possible marine retreat of ice sheet. Modeled paleoelevation at 13 ka using GI-31 ice history. Contours show the margin and thickness of ice at 13 ka. Shaded regions show ice margin at 11.5 ka. Region with reverse bedrock slope (1m/km) is highlighted by black arrow. This region of ice may have been subject to a marine ice sheet instability, where water at the base of the ice sheet induces melting, causing a rapidly retreating grounding line to induce a large mass loss in this region"

&

Title: "Ancient flooding of Bering Strait shows us how ice sheets respond to climate change"

https://phys.org/news/2020-02-ancient-bering-strait-ice-sheets.html

Extract: "Despite the sea-level data from the Bering Strait, that hypothesis hasn't been universally accepted, Pico said, in part because the study places the melting of the "saddle"—the region where the two North American ice sheets meet—at a time significantly later than many believe it was.

"Most people assume that happened earlier because, even though sea level was rising quickly around the world, there was a period—called meltwater pulse 1A—when it rose especially fast," she said. "In that period, sea level rose by 15 to 20 meters in under 300 years. That would require a huge amount of ice melt, and many people have assumed the saddle melted during this time.

"But that assumed history doesn't fit the Bering Strait sea-level record," she continued. "When we use that flooding history as a sea-level record, it's not consistent with what everyone had assumed before.""
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Hefaistos

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Re: Ice Apocalypse - MULTIPLE METERS SEA LEVEL RISE (narrated video)
« Reply #3191 on: May 17, 2020, 12:04:33 AM »
...  Unfortunately, AR5 and AR6 include a lot of low-end energy balance model simulations that use instantaneous radiative forcing which as the following quote indicates can result in efficacies that deviate considerably from unity; which can result in the calculation of low estimates of ECS (which are averaged together with more accurate estimates of ECS to result in a low bias for ECS in AR5 and likely in AR6).


All climate models have to obey fundamental laws of physics. The two relevant laws are the Stefan-Boltzmann Law and Conservation of Energy. This is why climate models have to be balanced at TOA.
« Last Edit: May 17, 2020, 12:14:58 AM by Hefaistos »

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Re: Ice Apocalypse - MULTIPLE METERS SEA LEVEL RISE (narrated video)
« Reply #3192 on: May 17, 2020, 04:53:38 PM »
...  Unfortunately, AR5 and AR6 include a lot of low-end energy balance model simulations that use instantaneous radiative forcing which as the following quote indicates can result in efficacies that deviate considerably from unity; which can result in the calculation of low estimates of ECS (which are averaged together with more accurate estimates of ECS to result in a low bias for ECS in AR5 and likely in AR6).


All climate models have to obey fundamental laws of physics. The two relevant laws are the Stefan-Boltzmann Law and Conservation of Energy. This is why climate models have to be balanced at TOA.

Instantaneous radiative forcing when viewed in insolation  result in values of ECS that are too low [i.e. using only observation-based data in the attached image from Armour (2016)], while when considering the time-dependence of the numerous consensus climate feedback mechanisms one finds that ECS is much higher (see the image).  Furthermore, when one considers non-consensus feedback mechanisms such as ice-climate feedbacks, more active negative aerosol feedbacks and more active positive cloud feedbacks then one finds that the high-end CMIP6 model projections for ECS are more likely.
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Re: Ice Apocalypse - MULTIPLE METERS SEA LEVEL RISE (narrated video)
« Reply #3193 on: May 17, 2020, 06:49:10 PM »
Most current consensus climate models assume the biome is all forest; which is an omission that could seriously compromise their climate change projections for reasons including that, as cited in the linked reference and associated article, Future global warming will result in the dehydration of peatlands that will expose their dense carbon stores to accelerated decomposition, and will turn them from firebreaks into fire propagators before the end of this century.

Helbig, M., Waddington, J.M., Alekseychik, P. et al. Increasing contribution of peatlands to boreal evapotranspiration in a warming climate. Nat. Clim. Chang. (2020). https://doi.org/10.1038/s41558-020-0763-7

https://www.nature.com/articles/s41558-020-0763-7

Abstract
The response of evapotranspiration (ET) to warming is of critical importance to the water and carbon cycle of the boreal biome, a mosaic of land cover types dominated by forests and peatlands. The effect of warming-induced vapour pressure deficit (VPD) increases on boreal ET remains poorly understood because peatlands are not specifically represented as plant functional types in Earth system models. Here we show that peatland ET increases more than forest ET with increasing VPD using observations from 95 eddy covariance tower sites. At high VPD of more than 2 kPa, peatland ET exceeds forest ET by up to 30%. Future (2091–2100) mid-growing season peatland ET is estimated to exceed forest ET by over 20% in about one-third of the boreal biome for RCP4.5 and about two-thirds for RCP8.5. Peatland-specific ET responses to VPD should therefore be included in Earth system models to avoid biases in water and carbon cycle projections.

See also:

Title: "Increased Threat of Fierce Fires and Accelerated Global Warming From Water Loss in Northern Peatlands"

https://scitechdaily.com/increased-threat-of-fierce-fires-and-accelerated-global-warming-from-water-loss-in-northern-peatlands/

Extract: "As the climate warms, air gets drier and can take up more water. In response to the drying of the air, forest ecosystems – which make up most of the world’s natural boreal regions – retain more water. Their trees, shrubs and grasses are vascular plants that typically take up carbon dioxide and release water and oxygen through microscopic pores in their leaves. In warmer, dryer weather, though, those pores close, slowing the exchange to conserve water.

Together with lakes, the spongy bogs and fens called peatlands make up the remainder of the boreal landscape. Peatlands store vast amounts of water and carbon in layers of living and dead moss. They serve as natural firebreaks between sections of forest, as long as they remain wet.

Peatland mosses are not vascular plants, so as warming continues, they are more prone to drying out. Unlike forests, they have no active mechanism to protect themselves from losing water to the atmosphere. Dehydration exposes their dense carbon stores to accelerated decomposition, and turns them from firebreaks into fire propagators, as shown in previous research from Waddington’s ecohydrology lab.

Drier peatlands mean bigger, more intense fires that can release vast amounts of carbon into the atmosphere, accelerating global warming, Helbig says.

“It’s crucial to consider the accelerated water loss of peatlands in a warming climate as we project what will happen to the boreal landscape in the next 100 to 200 years,” he says."
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AbruptSLR

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Re: Ice Apocalypse - MULTIPLE METERS SEA LEVEL RISE (narrated video)
« Reply #3194 on: May 17, 2020, 07:13:38 PM »
The linked reference, and the associated linked article, indicates that the Denman Glacier in East Antarctica is currently retreating relatively rapidly, and that it could be destabilized if modified CDW keeps causing the grounding line to retreat:

V. Brancato et al. Grounding line retreat of Denman Glacier, East Antarctica, measured with COSMO-SkyMed radar interferometry data, Geophysical Research Letters (2020). DOI: 10.1029/2019GL086291

https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2019GL086291

Abstract
Denman Glacier, East Antarctica, holds an ice volume equivalent to a 1.5 m rise in global sea level. Using satellite radar interferometry from the COSMO‐SkyMed constellation, we detect a 5.4±0.3 km grounding line retreat between 1996 and 2017‐2018. A novel reconstruction of the glacier bed topography indicates that the retreat proceeds on the western flank along a previously unknown 5 km wide, 1,800 m deep trough, deepening to 3,400 m below sea level. On the eastern flank, the grounding line is stabilized by a 10 km wide ridge. At tidal frequencies, the grounding line extends over a several kilometer‐wide grounding zone, enabling warm ocean water to melt ice at critical locations for glacier stability. If warm, modified Circumpolar Deep Water reaches the sub‐ice‐shelf cavity and continues to melt ice at a rate exceeding balance conditions, the potential exists for Denman Glacier to retreat irreversibly into the deepest, marine‐based basin in Antarctica.

Plain Language Summary
Using satellite radar data from the Italian COSMO‐SkyMed constellation, we document the grounding line retreat of Denman Glacier, a major glacier in East Antarctica that holds an ice volume equivalent to a 1.5 m global sea level rise. The grounding line is retreating asymmetrically. On the eastern flank, the glacier is protected by a subglacial ridge. On the western flank, we find a deep and steep trough with a bed slope that makes the glacier conducive to rapid retreat. If warm water continues to induce high rates of ice melt near the glacier grounding zone, the potential exists for Denman Glacier to undergo a rapid and irreversible retreat, with major consequences for sea level rise.

Key Points
•   CSK interferometric SAR observations of Denman Glacier, East Antarctica, reveal a 5.4±0.3 km grounding line retreat in the last twenty years
•   Denman Glacier is retreating along a deep trough, with a retrograde bed slope, deepening to 3.4 km below sea level, one of the deepest basins in Antarctica
•   The retrograde glacier bed and likely presence of warm water in the sub‐ice‐shelf cavity makes this region likely prone to marine instability

....

The linked article elaborates on Brancato et al. (2020) and indicates that the Denman Glacier in East Antarctica is much more susceptible to rapid ice mass loss than previously assumed primarily to the combination of bed topology and the intrusion of warm CDW that is causing the grounding line to retreat and causing the ice velocity to accelerate (see the two attached images, respectively):

Title: "Scientists Concerned As Denman Glacier Retreats Both Above and Below the Water Line"

https://scitechdaily.com/scientists-concerned-as-denman-glacier-retreats-both-above-and-below-the-water-line/

Extract: "The map below provides a three-dimensional view of the bed topography—the shape of the land surface and seafloor under the ice—around Denman Glacier, as derived from measurements made by radar and gravity-sensing instruments. The pink line delineates the grounding line as measured in 1996, while yellow indicates the line observed during the new study. (Ice flows from left to right on the map.) The darker the blues, the deeper the seafloor. Note the depth around and behind (left) the grounding line.

“Because of the shape of the ground beneath Denman’s western side, there is potential for the intrusion of warm water, which would cause rapid and irreversible retreat and contribute to global sea level rise,” said lead author Virginia Brancato, a scientist at JPL, formerly at UCI.

On its eastern flank, Denman Glacier runs into a 10-kilometer (6-mile) wide underwater ridge. On its western flank, however, the glacier sits over an 1800-meter deep trough that stretches well inland. If the grounding line keeps retreating, seawater could get funneled into that trough—which is smooth and slopes inland—and penetrate far into the continent. (The trough eventually dives to 3500 meters below sea level, the deepest land canyon on Earth.)

The scientists are concerned by the changes at Denman’ grounding line because there is potential for the glacier to undergo a rapid and irreversible retreat. As global temperatures rise and atmospheric and ocean circulation changes, warm water is increasingly being pushed against the shores of Antarctica by westerly winds.

“East Antarctica has long been thought to be less threatened, but as glaciers such as Denman have come under closer scrutiny, we are beginning to see evidence of potential marine ice sheet instability in this region,” said Eric Rignot, a cryospheric scientist at JPL and UCI and one of the study authors. “The ice in West Antarctica has been melting faster in recent years, but the sheer size of Denman Glacier means that its potential impact on long-term sea level rise is just as significant.”

This map depicts the velocity of the ice surfaces on and around Denman Glacier, as measured by the JPL/UCI team. Ice flows from left (grounded ice) to right (floating ice) in the image. About 24,000 square kilometers (9,000 square miles) of Denman floats on the ocean, mostly on the Shackleton Ice Shelf and Denman Ice Tongue. That floating ice has been melting from the bottom up at a rate of about 3 meters (10 feet) annually. These measurements, as well as the grounding line and seafloor measurements above, were made through the use of synthetic aperture radar data from the German Aerospace Center’s TanDEM-X satellite and the Italian COSMO-SkyMed satellites, as well laser altimetry data from NASA’s Operation IceBridge.

Recent research found that Denman Glacier lost roughly 268 gigatons (billion tons) of ice, or 7.0 gigatons per year, between 1979 and 2017. Until recently, researchers believed that East Antarctica was more stable than West Antarctica because eastern glaciers and ice sheets were not losing as much ice as those in the western part of the continent. If all of Denman melted, it would result in about 1.5 meters (5 feet) of sea level rise worldwide."
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AbruptSLR

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Re: Ice Apocalypse - MULTIPLE METERS SEA LEVEL RISE (narrated video)
« Reply #3195 on: May 18, 2020, 04:43:05 PM »
While the linked article is primarily a human interest story, that story emphasizes just how thin and fragile the Arctic sea ice has already become:

Title: "The Largest Arctic Science Expedition in History Finds Itself on Increasingly Thin Ice"

https://insideclimatenews.org/news/16052020/arctic-coronavirus-climate-science-mosaic-research

Extract: ""I went into it ready to be surprised, and it still got out ahead of me," he told me. "How fragile the ice has been. I knew it was gonna be thin, but it's still thinner and more fragile than I thought it would be.""
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Re: Ice Apocalypse - MULTIPLE METERS SEA LEVEL RISE (narrated video)
« Reply #3196 on: May 18, 2020, 04:57:19 PM »
The linked reference, and associated article, indicate that due to industrialization the high latitude coniferous forests are providing less cooling feedback than previously, which is resulting in more rapid high latitude warming:

Pontus Roldin, Mikael Ehn, Theo Kurtén, Tinja Olenius, Matti P. Rissanen, Nina Sarnela, Jonas Elm, Pekka Rantala, Liqing Hao, Noora Hyttinen, Liine Heikkinen, Douglas R. Worsnop, Lukas Pichelstorfer, Carlton Xavier, Petri Clusius, Emilie Öström, Tuukka Petäjä, Markku Kulmala, Hanna Vehkamäki, Annele Virtanen, Ilona Riipinen, Michael Boy. The role of highly oxygenated organic molecules in the Boreal aerosol-cloud-climate system. Nature Communications, 2019; 10 (1) DOI: 10.1038/s41467-019-12338-8

https://www.nature.com/articles/s41467-019-12338-8

Abstract

Over Boreal regions, monoterpenes emitted from the forest are the main precursors for secondary organic aerosol (SOA) formation and the primary driver of the growth of new aerosol particles to climatically important cloud condensation nuclei (CCN). Autoxidation of monoterpenes leads to rapid formation of Highly Oxygenated organic Molecules (HOM). We have developed the first model with near-explicit representation of atmospheric new particle formation (NPF) and HOM formation. The model can reproduce the observed NPF, HOM gas-phase composition and SOA formation over the Boreal forest. During the spring, HOM SOA formation increases the CCN concentration by ~10 % and causes a direct aerosol radiative forcing of −0.10 W/m2. In contrast, NPF reduces the number of CCN at updraft velocities < 0.2 m/s, and causes a direct aerosol radiative forcing of +0.15 W/m2. Hence, while HOM SOA contributes to climate cooling, NPF can result in climate warming over the Boreal forest.

See also:

Title: "Aerosols from coniferous forests no longer cool the climate as much"

https://www.sciencedaily.com/releases/2019/09/190925115119.htm

Extract: "Emissions of greenhouse gases have a warming effect on the climate, whereas small airborne particles in the atmosphere, aerosols, act as a cooling mechanism. That is the received wisdom in any case. However, new research can now show that the tiniest aerosols are increasing at the expense of the normal sized and slightly larger aerosols -- and it is only the latter that have a cooling effect.

One of the important natural sources of aerosols is the fragrant terpenes from coniferous forests. For example, the boreal coniferous forest area "the taiga" that stretches like a ribbon across the whole world, accounts for 14 per cent of the world's vegetation coverage, and is thus the world's largest coherent land ecosystem.

Through chemical reactions with the ozone in the atmosphere, the terpenes are transformed into highlyeavily oxygenatedidised organic molecules which bind with otherstick to aerosol particles that are already in the air. This leads to more cloud droplets, as each cloud droplet is formed through steam condensing on a sufficiently large aerosol particle. More cloud droplets lead to denser clouds and reduced insolation.

However, the new study published in Nature Communications shows that this "coniferous forest effect" has diminished due to industrialisation."
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AbruptSLR

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Re: Ice Apocalypse - MULTIPLE METERS SEA LEVEL RISE (narrated video)
« Reply #3197 on: May 18, 2020, 05:05:49 PM »
The linked reference, and associated article, indicate that the aerosol-cloud feedback is more negative than previously assumed by consensus climate scientists.  Thus as aerosol emissions decrease (as they have done during the COVID-19 crisis) the Earth will warm faster than previously projected by consensus climate science (such as projected in AR5):

Otto P. Hasekamp et al. Analysis of polarimetric satellite measurements suggests stronger cooling due to aerosol-cloud interactions, Nature Communications (2019). DOI: 10.1038/s41467-019-13372-2

https://www.nature.com/articles/s41467-019-13372-2

Abstract
Anthropogenic aerosol emissions lead to an increase in the amount of cloud condensation nuclei and consequently an increase in cloud droplet number concentration and cloud albedo. The corresponding negative radiative forcing due to aerosol cloud interactions (RFaciaci) is one of the most uncertain radiative forcing terms as reported in the 5th Assessment Report of the Intergovernmental Panel on Climate Change (IPCC). Here we show that previous observation-based studies underestimate aerosol-cloud interactions because they used measurements of aerosol optical properties that are not directly related to cloud formation and are hampered by measurement uncertainties. We have overcome this problem by the use of new polarimetric satellite retrievals of the relevant aerosol properties (aerosol number, size, shape). The resulting estimate of RFaciaci = −1.14 Wm−2−2 (range between −0.84 and −1.72 Wm−2−2) is more than a factor 2 stronger than the IPCC estimate that includes also other aerosol induced changes in cloud properties.

See also:

Title: "Cooling role of particulate matter on warming Earth stronger than previously thought"

https://phys.org/news/2019-12-cooling-role-particulate-earth-stronger.html

Extract: "The emission of particulate matter in the atmosphere is expected to decrease. Hasekamp says, "This means that the temperature will therefore rise faster, because the cooling will partly disappear. From the various climate predictions, those based on pessimistic models that assume more global warming, are more likely to be correct.""
“It is not the strongest or the most intelligent who will survive but those who can best manage change.”
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AbruptSLR

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Re: Ice Apocalypse - MULTIPLE METERS SEA LEVEL RISE (narrated video)
« Reply #3198 on: May 18, 2020, 08:05:27 PM »
This is just a reminder that Hein et al. (2020) has found that global warming will release more CO2 from tropical sediments due to increase precipitation.  This feedback mechanism has not yet been included in consensus climate science projections:

Title: "Wetter climate is likely to intensify global warming"

https://www.sciencedaily.com/releases/2020/05/200506133623.htm

Extract: "New study indicates the increase in rainfall forecast by global climate models is likely to hasten the release of carbon dioxide from tropical soils, further intensifying global warming by adding to human emissions of this greenhouse gas into Earth's atmosphere.

Previous research has highlighted the threat that global warming poses to the permafrost soils of the Arctic, whose widespread thawing is thought to be releasing up to 0.6 billion tons of carbon to the atmosphere each year.

"We've now found a similar climate feedback in the tropics," says Hein, "and are concerned that enhanced soil respiration due to greater precipitation -- itself a response to climate change -- will further increase concentrations of CO2 in our atmosphere.""
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AbruptSLR

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Re: Ice Apocalypse - MULTIPLE METERS SEA LEVEL RISE (narrated video)
« Reply #3199 on: May 18, 2020, 08:12:06 PM »
Over in the Consequences folder rboyd has noted that according to NASA GISS the first four months (Jan, Feb, March & April) average for 2020 ran 1.64C above the pre-industrial baseline,  now that average may very well drop after averaging all 12 months of 2020; but this data confirms that 2020 is currently on track to most likely be the warmest year on record.

NASA GISS posted at 1.15C anomaly for April (first four month of 2020 are 1.17, 1.24, 1.18 and 1.15).

First four months average of 1.19C (1.44C when compared to 1880-1920 baseline / 1.64C compared to 1750).

Highest anomalies in the Arctic Ocean and across Siberia.
“It is not the strongest or the most intelligent who will survive but those who can best manage change.”
― Leon C. Megginson