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Messages - AbruptSLR

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1
The linked reference (& associated article) indicate that recent studies of glacial earthquakes associated with Thwaites Glacier Calving events can help to improve projections of future ice mass loss from this key glacier:

J. Paul Winberry et al. (15 January 2020), "Glacial Earthquakes and Precursory Seismicity Associated With Thwaites Glacier Calving", Geophysical Research Letters, https://doi.org/10.1029/2019GL086178

https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2019GL086178

Abstract
We observe two (~MS 3) long‐period (10–30 s) seismic events that originate from the terminus of Thwaites Glacier, Antarctica. Serendipitous acquisition of satellite images confirm that the seismic events were glacial earthquakes generated during the capsizing of icebergs. The glacial earthquakes were preceded by 6 days of discrete high‐frequency seismic events that can be observed at distances exceeding 250 km. The high‐frequency seismicity displays an increasing rate of occurrence, culminating in several hours of sustained tremor coeval with the long‐period events. A series of satellite images collected during this precursory time period show that the high‐frequency events and tremor are the result of accelerating growth of ancillary fractures prior to the culminating calving event. This study indicates that seismic data have the potential to elucidate the processes by which Thwaites Glacier discharges into the ocean, thus improving our ability to constrain future sea level rise.

Plain Language Summary
Thwaites Glacier is one of the largest sources of Antarctic ice mass loss; however, the physics of the processes that control its discharge into the ocean remains incomplete. The long‐term stability of glaciers, such as Thwaites, that discharge directly into the ocean is linked to the rate of calving, the process of iceberg production. Spaceborne observations are crucial to understanding the calving processes; however, the typical repeat time of a satellite imagery is much longer than the typical duration of a calving event (minutes to hours). Increasingly, the seismic signals generated during calving are being used to complement other observations. For larger calving events, seismic energy can be recorded by remote seismic observation (hundreds to thousands of kilometers away from a glacier). While these glacier earthquakes are now regularly used to study calving in Greenland, only a limited number of glacial earthquakes have been observed in Antarctica. We show that Thwaites Glacier has now begun generating glacial earthquakes similar to those observed in Greenland. Additionally, we show that enhanced rates of fracturing can be seismically observed before the event. Our observations open a new avenue for understanding the behavior of Antarctica's leading source of mass loss.

See also:

Title: "Thwaites Glacier in Antarctica is Now Causing Earthquakes"

https://glacierhub.org/2020/03/05/thwaites-glacier-in-antarctica-is-now-causing-earthquakes/

Extract: "Combing through seismograph readings collected in West Antarctica during a large calving event at Thwaites on February 8th 2014, a team of researchers found evidence of two low frequency earthquakes, each about 10-30 seconds long. Their hunch—that the quakes came from the calving—was confirmed when they matched the seismograph readings with satellite images taken on the same day.

They also discovered high frequency blips of seismic activity that chirped on and off in the week preceding the event. Glaciologist and lead author of the study, Paul Winberry, explained to GlacierHub that in these short bursts they were actually “hearing all these little cracks start to propagate.” It was the sound of countless cracks forming and popping apart, heralding the large break about to come.

Thwaites is the only known glacier in Antarctica to exhibit seismic behavior, whereas glaciers in Greenland have been recorded causing earthquakes for some time. This difference can be explained by the fact that the majority of Greenland’s icebergs capsize when they break off into the water. The result is a more boisterous form of calving that produces detectable earthquakes. Why Greenland’s icebergs capsize and Antarctica’s do not has to do with the physical makeup of each landmass’s ice sheets and where they start to float on the water."

2
The linked Nature article discusses an ozone hole that has currently formed over the Arctic, and that this hole is worse than what happened in 1997 and 2011.  While a temporary Arctic ozone hole would not likely have a meaningful impact on climate change; nevertheless, it is discomforting that this event is worse than all previous events, and that if it is prolonged, or if future such events happen more frequently, this might have an impact on Arctic wind patterns; which might then have an impact of Arctic sea ice flow patterns.

Title: "Rare ozone hole opens over Arctic — and it’s big"

https://www.nature.com/articles/d41586-020-00904-w

Extract: "Cold temperatures and a strong polar vortex allowed chemicals to gnaw away at the protective ozone layer in the north.

A vast ozone hole — likely the biggest on record in the north — has opened in the skies above the Arctic. It rivals the better-known Antarctic ozone hole that forms in the southern hemisphere each year.

Record-low ozone levels currently stretch across much of the central Arctic, covering an area about three times the size of Greenland (see ‘Arctic opening’). The hole doesn’t threaten people’s health, and will probably break apart in the coming weeks. But it is an extraordinary atmospheric phenomenon that will go down in the record books.

The Arctic experienced ozone depletion in 1997 and in 2011, but this year’s loss looks on track to surpass those. “We have at least as much loss as in 2011, and there are some indications that it might be more than 2011,” says Gloria Manney, an atmospheric scientist at NorthWest Research Associates in Socorro, New Mexico. She works with a NASA satellite instrument that measures chlorine in the atmosphere, and says there is still quite a bit of chlorine available to deplete ozone in the coming days."

3
While currently 'Big Oil' is not leading the charge into renewable energy; however, their eventual adoption of more renewable energy would speed the transition to more sustainable power infrastructure.  Thus, 'Big Oil's currently wavering investments into sustainable energy is not good news.

Title: "Big Oil's interest in renewable energy investments expected to waver: report"

https://www.nsnews.com/big-oil-s-interest-in-renewable-energy-investments-expected-to-waver-report-1.24108471

Extract: "Budget cutting in response to the twin challenges of COVID-19 demand destruction and low oil prices mean the world's oil and gas industry will likely spend less on renewable energy going forward.

"In a US$60 per barrel oil price environment, most companies were generating strong cash flow and could afford to think about carbon mitigation strategies," said Valentina Kretzschmar, vice-president, corporate analysis, at Wood Mackenzie.

"But now ... all discretionary spend will be under review — that includes additional budget allocated for carbon mitigation. And companies that haven't yet engaged in carbon reduction strategies are likely to put the issue on the back burner.""

4
The linked research '... suggests that substantial reductions or instabilities of the AMOC could also occur in a future warmer climate.'

Thomas F. Stocker ( 27 Mar 2020), "Surprises for climate stability", Science, Vol. 367, Issue 6485, pp. 1425-1426, DOI: 10.1126/science.abb3569

https://science.sciencemag.org/content/367/6485/1425

Summary
Instabilities in Earth's climate system have intrigued scientists ever since analyses from Greenland ice cores revealed climate variations over the last hundred thousand years (1, 2). Abrupt changes were not singular events but a pervasive feature of the last ice age. Studies pointed to the ocean, specifically the Atlantic Meridional Overturning Circulation (AMOC), as a possible origin of these large swings (3, 4). Their occurrence in the distant past of the last ice age and their absence in the past 8000 years suggested that we are living in times of relative climate stability. On page 1485 of this issue, Galaasen et al. (5) report that over the past 500,000 years, there were disruptions in the formation of the North Atlantic Deep Water mass—an essential driver of the AMOC—during interglacial periods. This suggests that substantial reductions or instabilities of the AMOC could also occur in a future warmer climate.

http://www.sciencemag.org/about/science-licenses-journal-article-reuse

5
The linked article discusses the probability that the modern global socio-economic system is fragile to shocks whether from pandemics, climate change, or other perturbations from the norm:

Title: "Professor Sees Climate Mayhem Lurking Behind Covid-19 Outbreak"

https://www.bloomberg.com/news/articles/2020-03-28/professor-sees-climate-mayhem-lurking-behind-covid-19-outbreak

Extract: "“In modern industrial societies, the fallout from Covid-19 feels like a dress rehearsal for the kind of collapse that climate change threatens,” Bendell said in an interview. “This crisis reveals how fragile our current way of life has become.”

The University of Cumbria social-science professor is well-known among environmentalists for his theory of “deep adaptation.” In a 2018 paper, Bendell said that time was up for gradual measures to combat global warming. Without an abrupt transformation of society, changes in the planet’s climate would bring starvation, destruction, migration, disease and war -- the collapse of civilization -- within a decade."

6
The linked article indicates that many banks are still significantly supporting the fossil fuel industry via loans/finance:

Title: "Study: global banks 'failing miserably' on climate crisis by funneling trillions into fossil fuels"

https://www.theguardian.com/environment/2020/mar/18/global-banks-climate-crisis-finance-fossil-fuels

Extract: "Analysis of 35 leading investment banks shows financing of more than $2.66tn for fossil fuel industries since the Paris agreement"

7
'Banked' CFCs still represent a risk to accelerated climate change; and merit appropriate action:

Lickley, M., Solomon, S., Fletcher, S. et al. Quantifying contributions of chlorofluorocarbon banks to emissions and impacts on the ozone layer and climate. Nat Commun 11, 1380 (2020). https://doi.org/10.1038/s41467-020-15162-7

https://www.nature.com/articles/s41467-020-15162-7

Abstract
Chlorofluorocarbon (CFC) banks from uses such as air conditioners or foams can be emitted after global production stops. Recent reports of unexpected emissions of CFC-11 raise the need to better quantify releases from these banks, and associated impacts on ozone depletion and climate change. Here we develop a Bayesian probabilistic model for CFC-11, 12, and 113 banks and their emissions, incorporating the broadest range of constraints to date. We find that bank sizes of CFC-11 and CFC-12 are larger than recent international scientific assessments suggested, and can account for much of current estimated CFC-11 and 12 emissions (with the exception of increased CFC-11 emissions after 2012). Left unrecovered, these CFC banks could delay Antarctic ozone hole recovery by about six years and contribute 9 billion metric tonnes of equivalent CO2 emission. Derived CFC-113 emissions are subject to uncertainty, but are much larger than expected, raising questions about its sources.

See also:

Title: "Long Phased-Out Refrigeration and Insulation Chemicals Still Widely in Use and Warming the Climate"

https://insideclimatenews.org/news/17032020/cfc-ozone-layer-short-lived-climate-pollutants

Extract: "New study concludes that “banked” CFCs have greenhouse gas impacts equal to all registered U.S. cars and slow the shrinking of the ozone hole."

8
Apparently, the COVID-19 outbreak gave the Trump administration an excuse, last Thursday, to give the U.S. oil & gas industry 'an open license to pollute.'

Title: "Trump’s Move to Suspend Enforcement of Environmental Laws is a Lifeline to the Oil Industry"

https://insideclimatenews.org/news/27032020/coronavirus-covid-19-EPA-API-environmental-enforcement

Extract: "The American Petroleum Institute sought the EPA’s help for companies hurt by COVID-19. One former EPA official called the suspension “an open license to pollute.""

9
The linked reference indicates that climate sensitivity increases with increasing CO2 concentration faster than previously realized due to higher cloud feedback than previously assumed.

Jiang Zhu, Christopher J. Poulsen, Jessica E. Tierney. Simulation of Eocene extreme warmth and high climate sensitivity through cloud feedbacks. Science Advances, 2019; 5 (9): eaax1874 DOI: 10.1126/sciadv.aax1874

https://advances.sciencemag.org/content/5/9/eaax1874

Abstract
The Early Eocene, a period of elevated atmospheric CO2 (>1000 ppmv), is considered an analog for future climate. Previous modeling attempts have been unable to reproduce major features of Eocene climate indicated by proxy data without substantial modification to the model physics. Here, we present simulations using a state-of-the-art climate model forced by proxy-estimated CO2 levels that capture the extreme surface warmth and reduced latitudinal temperature gradient of the Early Eocene and the warming of the Paleocene-Eocene Thermal Maximum. Our simulations exhibit increasing equilibrium climate sensitivity with warming and suggest an Eocene sensitivity of more than 6.6°C, much greater than the present-day value (4.2°C). This higher climate sensitivity is mainly attributable to the shortwave cloud feedback, which is linked primarily to cloud microphysical processes. Our findings highlight the role of small-scale cloud processes in determining large-scale climate changes and suggest a potential increase in climate sensitivity with future warming.

See also:

Title: "Study of ancient climate suggests future warming could accelerate"

https://www.sciencedaily.com/releases/2019/09/190918142035.htm

Extract: ""We were surprised that the climate sensitivity increased as much as it did with increasing carbon dioxide levels," said first author Jiang Zhu, a postdoctoral researcher at the U-M Department of Earth and Environmental Sciences.

"It is a scary finding because it indicates that the temperature response to an increase in carbon dioxide in the future might be larger than the response to the same increase in CO2 now. This is not good news for us.""

10
The linked reference indicates that the MOC is subject to short-term disruptions that could abruptly cause it to slowdown in the future.

Eirik Vinje Galaasen, Ulysses S. Ninnemann, Augustin Kessler, Nil Irvalı, Yair Rosenthal, Jerry Tjiputra, Nathaëlle Bouttes, Didier M. Roche, Helga (kikki) F. Kleiven, David A. Hodell. Interglacial instability of North Atlantic Deep Water ventilation. Science, 2020 DOI: 10.1126/science.aay6381

https://science.sciencemag.org/content/367/6485/1485

Abstract
Disrupting North Atlantic Deep Water (NADW) ventilation is a key concern in climate projections. We use (sub)centennially resolved bottom water δ13C records that span the interglacials of the last 0.5 million years to assess the frequency of and the climatic backgrounds capable of triggering large NADW reductions. Episodes of reduced NADW in the deep Atlantic, similar in magnitude to glacial events, have been relatively common and occasionally long-lasting features of interglacials. NADW reductions were triggered across the range of recent interglacial climate backgrounds, which demonstrates that catastrophic freshwater outburst floods were not a prerequisite for large perturbations. Our results argue that large NADW disruptions are more easily achieved than previously appreciated and that they occurred in past climate conditions similar to those we may soon face.

11
Hopefully, lessons learn from the referenced study of tidal pressures near the grounding zone of the Ross Ice Shelf will be applied to models of the PIIS, and the TEIS, ocean interactions:

Carolyn Branecky Begeman, Slawek Tulaczyk, Laurie Padman, Matt King, Matthew R. Siegfried, Timothy O. Hodson and Helen A. Fricker1(6 March 2020), "Tidal pressurization of the ocean cavity near an Antarctic ice shelf grounding line", JGR Oceans, https://doi.org/10.1029/2019JC015562

https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2019JC015562?af=R

Abstract
Mass loss from the Antarctic Ice Sheet is sensitive to conditions in ice‐shelf grounding zones, the transition between grounded and floating ice. To observe tidal dynamics in the grounding zone, we moored an ocean pressure sensor to Ross Ice Shelf, recording data for 54 days. In this region the ice shelf is brought out of hydrostatic equilibrium by the flexural rigidity of ice, yet we found that tidal pressure variations at a constant geopotential surface were similar within and outside of the grounding zone. This implies that the grounding zone ocean cavity was overpressurized at high tide and underpressurized at low tide by up to 10 kPa with respect to glaciostatic pressure at the ice shelf base. Phase lags between ocean pressure and vertical ice‐shelf motion were tens of minutes for diurnal and semidiurnal tides, an effect that has not been incorporated into ocean models of tidal currents below ice shelves. These tidal pressure variations may affect the production and export of meltwater in the subglacial environment and may increase basal crevasse heights in the grounding zone by several meters, according to linear elastic fracture mechanics. We find anomalously high tidal energy loss at the K1 constituent in the grounding zone and hypothesize that this could be explained by seawater injection into the subglacial environment at high tide or internal tide generation through interactions with topography. These observations lay the foundation for improved representation of the grounding zone and its tidal dynamics in ocean circulation models of sub‐ice‐shelf cavities.

Plain language summary
One of the challenges for sea level rise prediction is understanding how the Antarctic ice sheets and the Southern Ocean interact. Ocean tides are an important component of this interaction, influencing ice shelf melting and the flow rate of grounded ice toward the coast. We report new observations relevant to this interaction: tidally‐varying ocean pressures where the ice first goes afloat to become an ice shelf. These tidal ocean pressure variations influence tidal currents below the ice shelf, and we propose that they also push seawater beneath the ice inland of the ice shelf and extend fractures at the ice‐shelf base. This study identifies tidal processes that may affect melt and fracture near the inland edge of ice shelves, a highly sensitive zone for ice dynamics.

Key Points
•   We present the first concurrent observations of ocean pressure and ice flexure in the grounding zone of an Antarctic ice shelf
•   Peak ocean pressure in the grounding zone at high tide exceeded glaciostatic pressure and preceded the peak ice shelf tidal deflection
•   These pressure variations may enhance basal crevassing and influence subglacial hydrology near the grounding line

12
The linked reference indicates that the interaction of oceanic induced ice melting and the calving of tidewater glaciers is not linear.  This implies that most consensus climate models of this interaction err on the side of least drama at higher oceanic ice melting rates (such as for the PIG and the Thwaites Glacier):

R. Mercenier, M.P. Lüthi  and A. Vieli (22 March 2020), "How oceanic melt controls tidewater glacier evolution", Geophysical Research Letters, https://doi.org/10.1029/2019GL086769

https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2019GL086769

Abstract
The recent rapid retreat of many Arctic outlet glaciers has been attributed to increased oceanic melt, but the relationship between oceanic melt and iceberg calving remains poorly understood. Here, we employ a transient finite‐element model that simulates oceanic melt and ice break‐off at the terminus. The response of an idealized tidewater glacier to various submarine melt rates and seasonal variations is investigated. Our modeling shows that for zero to low oceanic melt, the rate of volume loss at the front is similar or higher than for intermediate oceanic melt rates. Only very high melt rates lead to increasing volume losses. These results highlight the complex interplay between oceanic melt and calving and question the general assumption that increased submarine melt leads to higher calving fluxes and enhanced retreat. Models for tidewater glacier evolution should therefore consider calving and oceanic melt as tightly coupled processes rather than as simple, additive parametrizations.

Key Points
•   The effect of oceanic melt on tidewater glacier evolution is investigated using a transient calving model based on damage evolution
•   Oceanic melt has a complex influence on tidewater glacier evolution and increased melt rates may not necessarily lead to more volume loss
•   The calving and oceanic melt processes are not additive which has implications on the forcing of models for tidewater glacier evolution

13
The linked reference finds 60% more subglacial lakes in the Ellsworth Subglacial Highlands than previously assumed and also finds that the water catchment area for the Thwaites Glacier is much larger than previously assumed (see attached image). Both of these findings imply that current consensus models for the WAIS underestimate the risks for increasing ice mass loss with continued global warming.

Napoleoni, F., Jamieson, S. S. R., Ross, N., Bentley, M. J., Rivera, A., Smith, A. M., Siegert, M. J., Paxman, G. J. G., Gacitúa, G., Uribe, J. A., Zamora, R., Brisbourne, A. M., and Vaughan, D. G.: Subglacial lakes and hydrology across the Ellsworth Subglacial Highlands, West Antarctica, The Cryosphere Discuss., https://doi.org/10.5194/tc-2020-68, in review, 2020.

https://www.the-cryosphere-discuss.net/tc-2020-68/
https://www.the-cryosphere-discuss.net/tc-2020-68/tc-2020-68.pdf

Abstract. Subglacial water plays an important role in ice sheet dynamics and stability. It is often located at the onset of ice streams and has the potential to enhance ice flow downstream by lubricating the ice-bed interface. The most recent subglacial lake inventory of Antarctica mapped nearly 400 lakes, of which ~ 14 % are found in West Antarctica. Despite the potential importance of subglacial water for ice dynamics, there is a lack of detailed subglacial water characterization in West Antarctica. Using radio-echo sounding data, we analyse the ice-bed interface to detect subglacial lakes. We report 37 previously uncharted subglacial lakes and present a systematic analysis of their physical properties. This represents a ~ 60 % increase in subglacial lakes in the region. Additionally, a new digital elevation model of basal topography was built and used to create a detailed hydropotential model of Ellsworth Subglacial Highlands to simulate the subglacial hydrological network. This approach allows us to characterize basal hydrology, subglacial water catchments and connections between them. Furthermore, the simulated subglacial hydrological catchments of Rutford Ice Stream, Pine Island Glacier and Thwaites Glacier do not match precisely with their ice surface catchments.

Extract: "We observe that most of the subglacial water draining towards ASE is routed through the Bentley Subglacial Trench in the upper part of the hydrological catchment and driven through the Byrd Subglacial Basin towards the trunk of Thwaites Glacier. The high topography in the mid PIG catchment (Vaughan et al., 2006) means that the hydrological drainage system does not link to the faster flowing trunk of PIG. Instead, the basal hydrological system is captured by Thwaites. This drainage pattern has two main implications. Firstly, the subglacial hydrological catchments of PIG and Thwaites do not correspond to the ice catchments; they do not coincide either in position or size. Secondly, the hydrological system of TG trunk (Schroeder et al., 2013) may be fed by water sourced in the upper glaciological catchment of PIG, within the ESH. Any change in the water catchment of the TG, at the head of PIG, could therefore have important glaciological consequences for the ice dynamics of Thwaites Glacier and the wider ASE. This is particularly critical since the subglacial water drainage area of TG is bigger than previously thought and recent investigations (e.g., Smith et al., 2017) have demonstrated the presence of active subglacial lakes, in a cascade system-type, beneath the trunk of TG. Any water accumulation/drainage (e.g., chain of active subglacial lakes) in this area may affect the basal friction of the ice and therefore the ice flow velocity."

Partial Caption: "The red line indicates the boundary of the water catchment. The blue lines show the subglacial water drainage and the arrows indicates the general flow direction."


14
The linked reference discusses state of the art work on modeling geothermal heat flow in Antarctica.  The attached summary image makes it clear that the findings are not good news for the stability of key portions of the WAIS:

Burton-Johnson, A., Dziadek, R., and Martin, C.: Geothermal heat flow in Antarctica: current and future directions, The Cryosphere Discuss., https://doi.org/10.5194/tc-2020-59, in review, 2020.

https://www.the-cryosphere-discuss.net/tc-2020-59/
https://www.the-cryosphere-discuss.net/tc-2020-59/tc-2020-59.pdf

Abstract. Antarctic geothermal heat flow (GHF) affects the temperature of the ice sheet, determining its ability to slide and internally deform, as well as the behaviour of the continental crust. However, GHF remains poorly constrained, with few and sparse local, borehole-derived estimates, and large discrepancies in the magnitude and distribution of existing continent-scale estimates from geophysical models. We review the methods to extract GHF, compile borehole and probe-derived estimates from measured temperature profiles, and recommend the following future directions: 1) Obtain more borehole-derived estimates from the subglacial bedrock and englacial temperature profiles. 2) Estimate GHF beneath the interior of the East Antarctic Ice Sheet (the region most sensitive to GHF variation) via long-wavelength microwave emissivity. 3) Estimate GHF from inverse glaciological modelling, constrained by evidence for basal melting. 4) Revise geophysically-derived GHF estimates using a combination of Curie depth, seismic, and thermal isostasy models. 5) Integrate in these geophysical approaches a more accurate model of the structure and distribution of heat production elements within the crust, and considering heterogeneities in the underlying mantle. And 6) continue international interdisciplinary communication and data access.

Caption: "Fig. 16. Difference in heat flow values between the most recent magnetic (Martos et al., 2017) and seismic (An et al., 2015b) heat flow models."

15
The linked reference (& associated article) estimates that previous estimates of methane emissions associated with coal mining are about half of what they actually are, and that abandoned mine methane (AMM) emissions will continue for long after the coal mines are shut-down.  This is not good news:

Kholod, N. et al. (2020) Global methane emissions from coal mining to continue growing even with declining coal production, Journal of Cleaner Production, doi:10.1016/j.jclepro.2020.120489

https://www.sciencedirect.com/science/article/pii/S0959652620305369

Highlights
• This study presents estimates of global coal mine methane emissions through 2100.
• Methane emissions related to coal extraction are higher than reported from previous estimates.
• Coal mines continue emitting methane even if coal production is ceased.
• Evidence-based emission factors are applied to account for increasing mining depth.
• A new methodology for calculating emissions from abandoned mines is proposed.

Abstract
This paper presents projections of global methane emissions from coal mining under different coal extraction scenarios and with increasing mining depth through 2100. The paper proposes an updated methodology for calculating fugitive emissions from coal mining, which accounts for coal extraction method, coal rank, and mining depth and uses evidence-based emissions factors. A detailed assessment shows that coal mining-related methane emissions in 2010 were higher than previous studies show. This study also uses a novel methodology for calculating methane emissions from abandoned coal mines and represents the first estimate of future global methane emissions from those mines. The results show that emissions from the growing population of abandoned mines increase faster than those from active ones. Using coal production data from six integrated assessment models, this study shows that by 2100 methane emissions from active underground mines increase by a factor of 4, while emissions from abandoned mines increase by a factor of 8. Abandoned mine methane emissions continue through the century even with aggressive mitigation actions.

See also:

Title: "Coal mines emit more methane than oil-and-gas sector, study finds"

https://www.carbonbrief.org/coal-mines-emit-more-methane-than-oil-and-gas-sector-study-finds

Extract: "Methane emissions from coal mines could be more than double previous estimates, according to a new study."

The authors also note that, for the first time, they developed a methodology for estimating global methane emissions from old mining sites, suggesting a considerable role for abandoned mine methane (AMM), which in the past has been largely ignored. When factoring this in, coal methane emissions in 2020 rise to 114Mt.

“When active mines are closed, it is important to preserve information on the mine and prepare the mine to extract AMM in the future…it is clear that methane from closed mines will be a problem for years to come.”

16
The linked article discusses the possibility that as an economic stimulus measure associated with the novel corona virus outbreak, China's 14th five-year plan may (or may not) promote investments in coal-fire power plants.  All I can say is that I hope that other national leaders around the world do not possibly give in to similar temptations to simulate their economies by returning to their old habits of subsidizing/promoting the use of fossil fuels:

Title: "Analysis: Will China build hundreds of new coal plants in the 2020s?"

https://www.carbonbrief.org/analysis-will-china-build-hundreds-of-new-coal-plants-in-the-2020s

Extract: "China’s 14th five-year plan (FYP), setting out its national goals for 2021-2025, will arguably be one of the world’s most important documents for global efforts to tackle climate change.

The overarching plan for economic and social development in the world’s largest emitter is to be finalised and approved in early 2021, followed by more detailed sectoral targets over the next year. A power sector plan can be expected around winter 2021-22.

Ahead of the FYP’s publication, powerful stakeholders, such as the network operator State Grid and industry body the China Electricity Council, are lobbying for targets that would allow hundreds of new coal-fired power stations to be built. And a recent update to the “traffic light system” for new coal-power construction signaled further relaxation of permitting.
This is all despite significant overcapacity in the sector, with more than half of coal-power firms already loss-making and with typical plants running at less than 50% of their capacity.

As the country grapples with the coronavirus pandemic, however, controls on overcapacity may be vulnerable to the political priority of propping up economic growth. As a result, the restraints on another coal power boom are likely to be financial and economic, rather than regulatory.

Many experts and industry bodies argue for a move away from top-down targets and controls, to investment driven by market forces. However, the spending needed to fuel a new stimulus program can only be mobilized if investment is directed at the behest of the state, rather than the market – as a rule, China does not fund stimulus with on-budget spending, but by directing state-owned enterprises and commercial banks to spend more. In these circumstances, lack of controls on capacity additions runs a high risk of over-investment.

For example, efforts to control overcapacity might be vulnerable to the political priority of boosting investment spending to reach economic targets. An indication of this was the loosening of “traffic lights” for new coal-plant approvals, published by the National Energy Administration in February.

A new wave of coal power in China would pose clear risks for global efforts to limit climate change and could greatly complicate the country’s own energy transition. Yet even if the 14th five-year plan targets another coal boom, it could end up falling short due to economic and financial constraints.

There is a parallel in the 12th five-year plan. This created major overcapacity in the sector, but still fell far short of the target set for coal-power growth. Such an outcome would, however, create significant uncertainty, both for the domestic power industry and the international community."

17
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

See also:

Title: "East Antarctica's Denman Glacier has retreated almost 3 miles over last 22 years"

https://phys.org/news/2020-03-east-antarctica-denman-glacier-retreated.html

Extract: "East Antarctica's Denman Glacier has retreated 5 kilometers, nearly 3 miles, in the past 22 years, and researchers at the University of California, Irvine and NASA's Jet Propulsion Laboratory are concerned that the shape of the ground surface beneath the ice sheet could make it even more susceptible to climate-driven collapse.:

18
GRACE and GRACE-FO satellites indicate that Greenland's ice mass loss in the summer of 2019 was twice that of the 2002-2019 average.  When combined with the observed high ice mass loss rates from West Antarctica, that is not good news:

Title: "GRACE, GRACE-FO Satellite Data Track Ice Loss at the Poles"

https://scitechdaily.com/nasa-satellites-track-how-quickly-the-poles-are-melting-greenland-lost-600-billion-tons-of-ice-in-2-months/

Extract: "During the exceptionally warm Arctic summer of 2019, Greenland lost 600 billion tons of ice — enough to raise global sea levels by nearly a tenth of an inch (2.2 millimeters) in just two months, a new study shows.

Led by scientists at NASA’s Jet Propulsion Laboratory and the University of California, Irvine, the study also concludes that Antarctica continues to lose mass, particularly in the Amundsen Sea Embayment and the Antarctic Peninsula on the western part of the continent; however, those losses have been partially offset by gains from increased snowfall in the northeast.

For context, last summer’s losses are more than double Greenland’s 2002-2019 yearly average.
“In Antarctica, the mass loss in the west proceeds unabated, which will lead to an even further increase in sea level rise,” Velicogna said. “But we also observe a mass gain in the Atlantic sector of East Antarctica caused by an uptick in snowfall, which helps mitigate the enormous increase in mass loss that we have seen in the last two decades on other parts of the continent.”"

19
...
The objective of Governments, Central Banks and the Private Sector Oligarchs is to get through the covid-19 ASAP, enter a solid V-shaped recovery and BAU by the end of the year.

This will no doubt include throwing a few squillions of dosh at the fossil fuel industries, legacy auto-makers and aviation etc.  And guess who in the end will have to pay? You, me, the kids,and  their kids.
...

Maybe we should all feel lucky that the novel corona virus doesn't have the multi-billion dollar disinformation campaign budgets that the fossil fuel industry uses each year to delay effective climate action, otherwise, we wouldn't be entering a solid V-shaped recovery.  :P

20
People want wealth and wealthy people use more energy as discussed in the linked reference:

Oswald, Y., Owen, A. & Steinberger, J.K. Large inequality in international and intranational energy footprints between income groups and across consumption categories. Nat Energy 5, 231–239 (2020). https://doi.org/10.1038/s41560-020-0579-8

https://www.nature.com/articles/s41560-020-0579-8

Abstract: "Inequality in energy consumption, both direct and indirect, affects the distribution of benefits that result from energy use. Detailed measures of this inequality are required to ensure an equitable and just energy transition. Here we calculate final energy footprints; that is, the energy embodied in goods and services across income classes in 86 countries, both highly industrialized and developing. We analyse the energy intensity of goods and services used by different income groups, as well as their income elasticity of demand. We find that inequality in the distribution of energy footprints varies across different goods and services. Energy-intensive goods tend to be more elastic, leading to higher energy footprints of high-income individuals. Our results consequently expose large inequality in international energy footprints: the consumption share of the bottom half of the population is less than 20% of final energy footprints, which in turn is less than what the top 5% consume."

21
Paul Ehrlich makes some good points in the linked article about our current, and likely future, global situation:

Title: "Paul R. Ehrlich: A pandemic, planetary reckoning, and a path forward"

https://www.dailyclimate.org/pandemic-population-covid-19-2645545497.html

Extract: "The COVID-19 pandemic is bringing environmental destruction and the deterioration of social and cultural systems into sharp focus. But we can learn from this.

But nothing is more impractical than civilization trying to continue business as usual as it circles the drain.

The current pandemic disaster may end up damping down consumerism and improving the environment – there are reports of the lethal smog usually blanketing some Chinese cities clearing during pandemic lockdowns.

Maybe there's some chance that people are learning lessons.

We can always hope."

22
Many pundits ignore effective radiative forcing when discussing the likely impacts of reactive gases (like methane) and aerosols on GMSTA projections.  Nevertheless, these impacts are real and the linked reference helps to quantify such effective radiative forcings:

Thornhill, G. D., Collins, W. J., Kramer, R. J., Olivié, D., O'Connor, F., Abraham, N. L., Bauer, S. E., Deushi, M., Emmons, L., Forster, P., Horowitz, L., Johnson, B., Keeble, J., Lamarque, J.-F., Michou, M., Mills, M., Mulcahy, J., Myhre, G., Nabat, P., Naik, V., Oshima, N., Schulz, M., Smith, C., Takemura, T., Tilmes, S., Wu, T., Zeng, G., and Zhang, J.: Effective Radiative forcing from emissions of reactive gases and aerosols – a multimodel comparison, Atmos. Chem. Phys. Discuss., https://doi.org/10.5194/acp-2019-1205, in review, 2020.

https://www.atmos-chem-phys-discuss.net/acp-2019-1205/

Abstract. This paper quantifies the effective radiative forcing from CMIP6 models of the present-day anthropogenic emissions of NOx, CO, VOCs, SO2, NH3, black carbon and primary organic carbon. Effective radiative forcing from pre-industrial to present-day changes in the concentrations of methane, N2O and halocarbons are quantified and attributed to their anthropogenic emissions.

Emissions of reactive species can cause multiple changes in the composition of radiatively active species: tropospheric ozone, stratospheric ozone, secondary inorganic and organic aerosol and methane. We therefore break down the ERFs from each emitted species into the contributions from the composition changes.

The 1850 to 2014 mean ERFs are 1.1 ± 0.07 W m−2 for sulfate, −0.24 ± 0.01 W m−2 for organic carbon (OC), and 0.15 ± 0.04 W m−2 for black carbon (BC), and for the aerosols combined it is −0.95 ± 0.03 W m−2. The means for the reactive gases are 0.69 ± 0.04 W m−2 for methane (CH4), 0.06 ± 0.04 W m−2 for NOx, −0.09 ± 0.03 W m−2 for volatile organic carbons (VOC), 0.16 ± 0.03 W m−2 for ozone (O3), 0.27 W m−2 for nitrous oxide (N2O) and −0.02 ± 0.06 W m−2 for hydrocarbon (HC). Differences in ERFs calculated for the different models reflect differences in the complexity of their aerosol and chemistry schemes, especially in the case of methane where tropospheric chemistry captures increased forcing from ozone production.

23
While the linked reference focuses on how SLR will influence estuarine hydrodynamics in populated areas; I note that the indicated changes in parameters including: tidal range and tidal bores will also serve to reduce the stability of key Antarctic marine glaciers and key Greenland marine terminating glaciers:

Danial Khojasteh et al. (16 March 2020), "Sea level rise and estuarine tidal dynamics: A review", Earth-Science Reviews, 103166, https://doi.org/10.1016/j.earscirev.2020.103166

https://www.sciencedirect.com/science/article/abs/pii/S0012825219307640?dgcid=rss_sd_all

Highlights
• A critical review is provided on how sea level rise (SLR) will influence estuarine hydrodynamics and knowledge gaps are identified.
• Current literature is inconclusive regarding the influences of SLR on estuarine hydrodynamics.
• Hydrodynamic modelling, rather than static approaches, is needed when assessing estuarine responses to SLR.
• Under SLR, the estuarine shape, bathymetry, friction, reflection and tidal resonance influence estuarine hydrodynamic parameters, including tidal range, tidal wave asymmetry, saltwater intrusion, and mixing.
• A conceptual framework is provided to highlight the likely responses of different types of estuaries to SLR.

Abstract
Sea level rise (SLR) poses a hazard to assets, ecosystems, and economies in coastal zones, including over 600 million people worldwide who currently reside near estuaries. SLR implications include more frequent oceanic inundation, shoreline erosion, and the failure of stormwater and drainage infrastructure. To predict and manage these potential impacts, a comprehensive understanding of SLR on estuarine hydrodynamics was assessed via a review of existing theory and available literature. The review highlighted that the most common method of assessing SLR impacts in estuaries has been via simplistic static approaches, such as elevation-based water level projections, that are of limited value as they do not include fundamental hydrodynamic responses to estuarine entrance restriction, geometry, bathymetry, friction, and floodplain connectivity. A much smaller number of studies have conducted hydrodynamic modelling of SLR in estuaries showing that estuarine shape, bathymetry, friction, reflection and resonance have a strong influence on estuarine hydrodynamic parameters such as tidal range and asymmetry, saltwater intrusion, and mixing. The majority of the existing SLR estuarine hydrodynamic literature has focused on the influence of estuarine tidal parameters providing conflicting results in terms of influence of SLR on estuarine tidal dynamics and patterns. For most studies, the saltwater intrusion length of the estuary was shown to increase under SLR, whereas very few studies examined the influence of SLR on estuary entrance condition, friction, reflection, resonance, and mixing. A significant knowledge gap identified was the lack of a generic framework to conceptualise how different estuary types respond to SLR based on shape, bathymetry, and entrance condition. To this aim, several conceptual models are introduced to highlight the role of tidal friction, resonance and tidal wave penetration in estuaries under SLR.

24
The linked reference indicates that most likely future Arctic sea ice losses will increase the frequency of Central Pacific El Nino events; which is particularly bad news for WAIS stability due to the like increase of Equatorial Pacific energy advected to West Antarctica via atmospheric Rossby Waves:

Hyerim Kim et al. (11 March 2020), "Arctic sea ice loss as a potential trigger for Central Pacific El Niño events", Geophysical Research Letters, https://doi.org/10.1029/2020GL087028

https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2020GL087028?af=R

Abstract
Little attention has been paid to the influence of Arctic sea ice loss on climate variability in the tropical Pacific. By analyzing observational datasets, we hypothesized that anomalous Arctic sea ice concentration variations have the potential to influence tropical Pacific sea surface temperature (SST) variability via atmosphere‐ocean coupled processes in the eastern subtropical North Pacific. To test this hypothesis, we conducted idealized model experiments with 15 ensembles in which historical SSTs for 1951‐2016 were restored in the Arctic only with different initial conditions. We found that a positive phase of North Pacific Oscillation–like atmospheric circulation, which is modulated by a sea ice reduction in the Pacific Arctic sector, triggers El Niño–like warming in the central tropical Pacific. This implies that connections between the Arctic and the tropics should be considered for further understanding of changes in El Niño and other tropical Pacific climate variability in a changing climate.

25
As my schedule has become busier than previously, I will likely maker fewer posts than recent years.  Thus, I thought I would make a somewhat more philosophical post today by raising the question of what does the Paris Agreement mean when it set a goal of staying 'well below 2C'?

Furthermore, I raise the following sub-topics:

1. As I have previously noted the Paris Agreement probably would not have even adopted the 'well below 2C' goal if it had not been concerned about fat right-tailed risks, which raises the question of what right-screwed PDF did Paris assume and how much has the shape of that PDF changed since 2015?

2. What baseline did Paris assume and what baseline should have it used to measure 2C?

3. Evidently, Paris did not feel comfortable defining what it meant by 'well below' otherwise, it would have used a specific value, or a specific range, like 0.25C to 0.4C below 2C.  Possible reasons that Paris may not have felt comfortable include that 'well below' depends on:
a) Which socio-economic pathway we collectively choose to follow;
b) How much climate variability increases with increasing GMSTA and,
c) How much confidence did Paris have in the AR5 projections w.r.t. variables like: climate sensitivity, ice-climate feedbacks and initial boundary conditions.

4. What confidence range did Paris assume was appropriate when considering issues like:
a) Tipping points,
b) Reversibility and
c) Socio-economic fragility.

5. Much of the current progress in reduction in CO2 emissions has been achieved by substituting coal with natural gas; thus:
a) Do decision makers currently think that collectively we have made more progress in the fight against climate change than we actually have because we are discounting the methane emissions associated with the increased use of natural gas?
b) Will it become more difficult to reduce crude oil and natural gas consumption that it was to reduce coal consumption because of a lack of economically available substitutes?
c) If economic times become harder, will coal consumption increase again in future years?

6. If consensus climate scientists have underestimated the negative feedback associated with anthropogenic aerosol emissions; will future reductions in anthropogenic aerosol emissions drive GMSTA closer to 'well below 2C' even with declining GHG emissions?

26
While the PALeo constraints on SEA level rise (PALSEA) program will not be complete until the end of 2021; it is still worth remembering that the paleo-record contains numerous instances of extremely rapid sea level rise with durations ranging from decades to centuries.  It will be good to learn what PALSEA finally reports after 2021:

Title: "PALSEA - PALeo constraints on SEA level rise"

http://pastglobalchanges.org/science/wg/palsea/intro

Extract: "PALSEA is a continuation of PALSEA1, which operated from 2008 to 2012, and PALSEA2, which operated from 2013-2017.
This third phase of the group runs from 2019-2021.

Sea-level rise due to polar ice-sheet retreat in a warming world is one of the most important, and uncertain aspects associated with future climate change. The geologic record, features major, and sometimes rapid, changes in ice sheets and sea level that offers an excellent opportunity to assess the rates, magnitudes, and processes involved in ice-sheet and sea-level change, as well as their connection to climate forcings."

See also:

Title: "Ocean Circulation and Carbon Cycling"

http://pastglobalchanges.org/products/pages-magazine/12916

Edit: Also, I note that the image is from 2015 when GMSTA was about 0.9C but it is now officially over 1.1C.

27
I think the goal is to offer 3 scenarios of policy changes.
...

If it is not clear in the cartoon, the figure with the hat is the decision maker and the figures without hats are consensus climate scientists.

28
Consequences / Re: COVID-19
« on: March 13, 2020, 02:09:32 PM »
The attached image from Vox showing the ratio of COVID-19 test kits vs the population of key countries, shows how ill prepared the Trump Administration is to address this epidemic in the U.S.A.

Edit, see also:

Title: "Why the U.S. is so far behind on coronavirus testing"

https://www.axios.com/coronavirus-testing-labs-delay-a3868ece-a2e5-4ed2-8822-44d20c73774d.html

Extract: "Some of the nation’s best academic laboratories wanted to begin developing their own coronavirus diagnostic tests early last month, but were blocked by federal rules about test development.

Why it matters: The U.S. is woefully behind in mass deployment of tests to detect coronavirus, determine its spread and isolate hot spots. Once given the go-ahead to develop tests under more relaxed terms, some of these labs were able to get tests up and running in a matter of days.
...
The bottom line: As of yesterday, the U.S. has the capacity to test about 22,000 people a day, although it's unclear how many people are actually being tested. South Korea — which has a significantly smaller population — is testing nearly 20,000 people a day, the BBC reports."

29
The linked article discusses a new government-industries guide for UK pension funds as to how they might assess up-coming climate change risk, and they recommend including an analysis of at least one scenario assuming a "no transition, pathway to 4+oC":

Title: "UK pension trustees presented with guide to climate-related risks"

https://www.ipe.com/news/uk-pension-trustees-presented-with-guide-to-climate-related-risks/10044243.article

Extract: "The Pensions Climate Risk Industry Group (PCRIG), as it was named, described the guide, as “structured sequentially based on the way a pension trustee board might typically approach decision-making”.

It recommends scenario analysis as “a helpful technique for trustees to assess their scheme’s resilience to different future outcomes”. Three scenarios are recommended: an orderly transition to a 2⁰C or lower scenario; an abrupt transition to a 2⁰C or lower scenario, and a “no transition, pathway to 4+⁰C scenario”.

30
Paleontologists discover solid evidence of formerly elusive abrupt sea-level jump

...

https://www.sciencedaily.com/releases/2020/03/200310094223.htm

For those who do not like to click on links, I provide the following reference that presents findings that kassy discussed.  Also, I note that much of the abrupt sea level rise contributions for the Meltwater pulses during the transition to the Holocene came from marine glaciers situated in various portions of the current Antarctic continental shelf.

Skye Yunshu Tian, Moriaki Yasuhara, Yuanyuan Hong, Huai-Hsuan M. Huang, Hokuto Iwatani, Wing-Tung Ruby Chiu, Briony Mamo, Hisayo Okahashi, Tine L. Rasmussen. Deglacial–Holocene Svalbard paleoceanography and evidence of meltwater pulse 1B. Quaternary Science Reviews, 2020; 233: 106237 DOI: 10.1016/j.quascirev.2020.106237

https://www.sciencedirect.com/science/article/abs/pii/S0277379119309485?via%3Dihub

Abstract
Better understanding of deglacial meltwater pulses (MWPs) is imperative for future predictions of human-induced warming and abrupt sea-level change because of their potential for catastrophic damage. However, our knowledge of the second largest meltwater pulse MWP-1B that occurred shortly after the start of the Holocene interglacial remains very limited. Here, we studied fossil ostracods as paleoenvironmental indicators of water depth, salinity, and temperature in two marine sediment cores from Storfjorden, Svalbard margin (the Arctic Ocean), to investigate near-field (i.e. areas located beneath continental ice sheets at the Last Glacial Maximum) evidence of MWP-1B. The depositional environment changed from a cold bathyal environment to a warmer bathyal environment at ∼11,300 yr BP indicating incursion of warm Atlantic water into the Nordic seas, and eventually to a cold neritic environment by ∼11,000 yr BP because of melting of the Svalbard-Barents Sea ice sheet and resultant isostatic rebound. This process corresponds to rapid relative sea-level fall of 40–80 m of MWP-1B from ∼11,300 to 11,000 yr BP.

31
To those who follow this thread, the linked article and associated reference come a no surprise:

Title: "Six-fold jump in polar ice loss lifts global oceans"

https://phys.org/news/2020-03-six-fold-polar-ice-loss-global.html

Extract: "Greenland and Antarctica are shedding six times more ice than during the 1990s, driving sea level rise that could see annual flooding by 2100 in regions home today to some 400 million people, scientists have warned."

See also:

Shepherd, A., Ivins, E., Rignot, E. et al. Mass balance of the Greenland Ice Sheet from 1992 to 2018. Nature 579, 233–239 (2020). https://doi.org/10.1038/s41586-019-1855-2

https://www.nature.com/articles/s41586-019-1855-2

Abstract: "The Greenland Ice Sheet has been a major contributor to global sea-level rise in recent decades, and it is expected to continue to be so3. Although increases in glacier flow and surface melting have been driven by oceanic and atmospheric warming, the magnitude and trajectory of the ice sheet’s mass imbalance remain uncertain. Here we compare and combine 26 individual satellite measurements of changes in the ice sheet’s volume, flow and gravitational potential to produce a reconciled estimate of its mass balance. The ice sheet was close to a state of balance in the 1990s, but annual losses have risen since then, peaking at 345 ± 66 billion tonnes per year in 2011. In all, Greenland lost 3,902 ± 342 billion tonnes of ice between 1992 and 2018, causing the mean sea level to rise by 10.8 ± 0.9 millimetres. Using three regional climate models, we show that the reduced surface mass balance has driven 1,964 ± 565 billion tonnes (50.3 per cent) of the ice loss owing to increased meltwater runoff. The remaining 1,938 ± 541 billion tonnes (49.7 per cent) of ice loss was due to increased glacier dynamical imbalance, which rose from 46 ± 37 billion tonnes per year in the 1990s to 87 ± 25 billion tonnes per year since then. The total rate of ice loss slowed to 222 ± 30 billion tonnes per year between 2013 and 2017, on average, as atmospheric circulation favoured cooler conditions and ocean temperatures fell at the terminus of Jakobshavn Isbræ. Cumulative ice losses from Greenland as a whole have been close to the rates predicted by the Intergovernmental Panel on Climate Change for their high-end climate warming scenario17, which forecast an additional 70 to 130 millimetres of global sea-level rise by 2100 compared with their central estimate."

32
For those who want to read more about the International Thwaites Glacier Collaboration (ITGC) five-year program, I provide the following link to a relevant article:

Title: "Investigating Thwaites: the riskiest glacier on Earth"

http://geographical.co.uk/nature/polar/item/3606-investigating-thwaites-the-riskiest-glacier-on-earth

Extract: "Dubbed the riskiest glacier on Earth, an ongoing project to learn more about Thwaites is vital to ensure the accuracy of sea-level rise predictions"

33
The linked article and WMO State of the Global Climate in 2019 report card indicates that climate change continued advance in 2019:

Title: "We've Officially Passed The Threshold of 1.1 Degree Celsius Warming"

https://www.sciencealert.com/the-last-five-years-were-the-warmest-ever-recorded-again

Extract: "Global average temperatures in 2019 were 1.1 degrees Celsius above pre-industrial levels. Only 2016 was hotter, but that year came at the end of an extreme El Niño, which typically has a warming influence on global temperatures."

See also:

Title: "WMO Statement on the State of the Global Climate in 2019"

https://library.wmo.int/index.php?lvl=notice_display&id=21700#.XmkbKHOSmUk
https://library.wmo.int/doc_num.php?explnum_id=10211

Caption: "Figure 14. Annual (blue) and cumulative (red) mass balance of reference glaciers with more than 30 years of ongoing glaciological measurements. Global mass balance is based on an average for 19 regions to minimize bias towards well-sampled regions. Annual mass changes are expressed in meter water equivalent (m w.e.) which corresponds to tonnes per square meter (1 000 kg m-2) (Source: World Glacier Monitoring Service (WGMS, 2020, updated)."

34
The analysis at the linked website find that whether considering only long-lived GHG emissions or both long and short-lived GHG emissions from food; it is a good idea to become a vegetarian:

Title: "The carbon footprint of foods: are differences explained by the impacts of methane?"

https://ourworldindata.org/carbon-footprint-food-methane

Extract: "This data suggests that the most effective way to reduce the climate impact of your diet is to eat less meat overall, especially red meat and dairy

In this post I want to investigate whether these conclusions depend on the particular metric we rely on to quantify greenhouse gas (GHG) emissions. It could be argued that red meat and dairy have a much higher footprint because its emissions are dominated by methane – a greenhouse gas that is much more potent but has a shorter lifetime in the atmosphere than carbon dioxide. Methane emissions have so far driven a significant amount of warming – with estimates ranging from around 23% to 40% of the total – to date."

35
Antarctic ice shelves have a variety of bathymetry/ice shelf/water column/etc. configurations and thus different Antarctic ice shelves have responded differently to the recent increase in the upwelling of warm CDW (Circumpolar Deep Water) associated with the recent increase in peak westerly wind velocities over the Southern Ocean.  While the PIIS, TEIS and the Thwaites Ice Tongue are examples of ice shelves that have already been significantly impacted by the westerly wind driven increase in upwelled CDW; the linked reference and associated article discuss the findings of field research on the Getz Ice Shelf, that indicates that the geometry of its ice face limits the transmission of the upwelled CDW beneath the ice shelf to the depth-varying (baroclinic) component, which is typically much smaller than the full upwelled flux of CDW.  However, the researchers warn that a projected increase of low-pressure atmospheric systems near such ice faces could increase the flux of warm beneath such ice shelves (as the Getz Ice Shelf) with continued global warming:

A. K. Wåhlin, N. Steiger, E. Darelius, K. M. Assmann, M. S. Glessmer, H. K. Ha, L. Herraiz-Borreguero, C. Heuzé, A. Jenkins, T. W. Kim, A. K. Mazur, J. Sommeria and S. Viboud (26 February 2020), “Ice front blocking of ocean heat transport to an Antarctic ice shelf”, Nature, DOI: 10.1038/s41586-020-2014-5

https://www.nature.com/articles/s41586-020-2014-5

Abstract: "Mass loss from the Antarctic Ice Sheet to the ocean has increased in recent decades, largely because the thinning of its floating ice shelves has allowed the outflow of grounded ice to accelerate. Enhanced basal melting of the ice shelves is thought to be the ultimate driver of change, motivating a recent focus on the processes that control ocean heat transport onto and across the seabed of the Antarctic continental shelf towards the ice. However, the shoreward heat flux typically far exceeds that required to match observed melt rates, suggesting that other critical controls exist. Here we show that the depth-independent (barotropic) component of the heat flow towards an ice shelf is blocked by the marked step shape of the ice front, and that only the depth-varying (baroclinic) component, which is typically much smaller, can enter the sub-ice cavity. Our results arise from direct observations of the Getz Ice Shelf system and laboratory experiments on a rotating platform. A similar blocking of the barotropic component may occur in other areas with comparable ice–bathymetry configurations, which may explain why changes in the density structure of the water column have been found to be a better indicator of basal melt rate variability than the heat transported onto the continental shelf. Representing the step topography of the ice front accurately in models is thus important for simulating ocean heat fluxes and induced melt rates."

See also:

Title: "Physics Shows Antarctic Glacier Ice Walls Are Vital Protection for the Climate"

https://scitechdaily.com/physics-shows-antarctic-glacier-ice-walls-are-vital-protection-for-the-climate/

Extract: "“What we found here is a crucial feedback process: the ice shelves are their own best protection against warm water intrusions. If the ice thins, more oceanic heat comes in and melts the ice shelf, which becomes even thinner etc. It is worrying, as the ice shelves are already thinning because of global air and ocean warming,” says Céline Heuzé, climate researcher at the Department of Earth Sciences of Gothenburg University."

“From the Getz glacier, we are receiving measurements of heat transport in the ocean that correspond with the melting ice being measured by satellites. This also means that the floating glaciers – the ice fronts in particular – are key areas that should be closely monitored. If the ice walls were to disappear, much greater levels of thermal energy would be released towards the ice on land.”

“Consequently, we no longer expect to see a direct link between increasing westerly winds and growing levels of melting ice. Instead, the increased water levels can be caused by the processes that pump up warmer, heavier water to the continental shelf, for example as low-pressure systems move closer to the continent.”

Researchers believe that the studies have provided them with significantly better tools to be able to predict future water levels and create more accurate climate prognoses."

36
This article, from early 2016, explains why Russia and Saudi Arabia are so desperate that they're willing to risk a global recession.

...

Ken,

As no one actually knows how much anthropogenic GHG emissions there will be in coming decades, I will agree to stop posting information on that topic if you do so also, in order not to swamp this thread with information on that topic; which is covered well in other threads of this forum.

Best,
ASLR

37
Consequences / Re: COVID-19
« on: March 10, 2020, 10:41:38 PM »
The linked 'The Atlantic' article from yesterday quantifies the dangerous delays in U.S. COVID-19 testing:

Title: "The Dangerous Delays in U.S. Coronavirus Testing Haven’t Stopped"

https://www.theatlantic.com/health/archive/2020/03/coronavirus-testing-numbers/607714/

Extract: "Nearly two weeks after the new coronavirus was first found to be spreading among Americans, the United States remains dangerously limited in its capacity to test people for the illness, an ongoing investigation from The Atlantic has found.

After surveying local data from across the country, we can only verify that 4,384 people have been tested for the coronavirus nationwide, as of Monday at 4 p.m. eastern time. These data are as comprehensive a compilation of official statistics as currently possible.

The sluggish rollout of the tests has become a debilitating weakness in America’s response to the spread of the coronavirus. By this point in its outbreak, South Korea had tested more than 100,000 people for the disease, and it was testing roughly 15,000 people every day. The United Kingdom, where three people have died of COVID-19, has already tested more than 24,900 people."

38
The linked reference indicates that the Amazon rainforest could collapse within the next 50-years.

Cooper, G.S., Willcock, S. & Dearing, J.A. Regime shifts occur disproportionately faster in larger ecosystems. Nat Commun 11, 1175 (2020). https://doi.org/10.1038/s41467-020-15029-x

https://www.nature.com/articles/s41467-020-15029-x

Abstract: "Regime shifts can abruptly affect hydrological, climatic and terrestrial systems, leading to degraded ecosystems and impoverished societies. While the frequency of regime shifts is predicted to increase, the fundamental relationships between the spatial-temporal scales of shifts and their underlying mechanisms are poorly understood. Here we analyse empirical data from terrestrial (n = 4), marine (n = 25) and freshwater (n = 13) environments and show positive sub-linear empirical relationships between the size and shift duration of systems. Each additional unit area of an ecosystem provides an increasingly smaller unit of time taken for that system to collapse, meaning that large systems tend to shift more slowly than small systems but disproportionately faster. We substantiate these findings with five computational models that reveal the importance of system structure in controlling shift duration. The findings imply that shifts in Earth ecosystems occur over ‘human’ timescales of years and decades, meaning the collapse of large vulnerable ecosystems, such as the Amazon rainforest and Caribbean coral reefs, may take only a few decades once triggered."

See also:

Title: "Amazon and other large ecosystems at risk of rapid collapse: study"

https://www.reuters.com/article/us-climate-change-collapse/amazon-and-other-large-ecosystems-at-risk-of-rapid-collapse-study-idUSKBN20X2MF

Extract: "Large ecosystems such as the Amazon rainforest and coral reefs could collapse faster than scientists had previously assumed, according to a study published on Tuesday."

Researchers crunched data on changes in dozens of ecosystems to conclude that Caribbean coral reefs could collapse in 15 years while the Amazon rainforest could die back within 50 years - although that finding was questioned by some experts."

39
Policy and solutions / Re: Oil and Gas Issues
« on: March 10, 2020, 08:33:40 PM »
Remember back a few weeks ago when the projections (by the fossil fuel shills) for the US shale patch was an increase in production of over a million barrels per day?

https://seekingalpha.com/news/3550186-u-s-oil-production-take-20-hit-on-shale-retreat-pioneer-ceo-says

Quote
U.S. oil production could take 20% hit on shale retreat, Pioneer CEO says
Mar. 10, 2020

According to the Washington Post, the White House will likely pursue federal aid to help support the U.S. shale industry.


Quote
The U.S. could lose 2M-2.5M bbl/day in output - a nearly 20% drop - by the end of 2021 if oil prices stay around current levels as companies go into "maintenance mode," CEO Scott Sheffield tells Bloomberg.

Most shale producers will be forced to cut as many as half of their drilling rigs by the end of this year, when current hedges expire, the CEO says.

40
While the factory shutdowns in China may put a temporary slowdown on solar and wind projects, the damage to the oil and gas companies from the slowdown will result in more money being invested in renewables, not fossil fuel companies.

...

Even if western power companies do eventually decide to slow their investments in fossil fuels; the same economics do not apply to Russian and/or OPEC oil production as they have hundreds of years of oil&gas in the ground that is worthless to them unless they produce & sell those resources even at low prices.  Russia and Saudi Arabia have currently increased crude oil production primarily to damage the U.S. shale industry, and in the future they will not hesitate to repeat such actions if/when they feel threatened by renewable energy sources.

41
The linked pdf provides a convenient overview of many of the dynamical aspects of climate change.

Michael Ghil and Valerio Lucarini (2020), "The Physics of Climate Variability and Climate Change" by; arXiv:1910.00583v2

https://arxiv.org/pdf/1910.00583.pdf

Abstract: "The climate system is a forced, dissipative, nonlinear, complex and heterogeneous system that is out of thermodynamic equilibrium. The system exhibits natural variability on many scales of motion, in time as well as space, and it is subject to various external forcings, natural as well as anthropogenic. This paper reviews the observational evidence on climate phenomena and the governing equations of planetary-scale flow, as well as presenting the key concept of a hierarchy of models as used in the climate sciences. Recent advances in the application of dynamical systems theory, on the one hand, and of nonequilibrium statistical physics, on the other, are brought together for the first time and shown to complement each other in helping understand and predict the system’s behavior. These complementary points of view permit a self-consistent handling of subgrid-scale phenomena as stochastic processes, as well as a unified handling of natural climate variability and forced climate change, along with a treatment of the crucial issues of climate sensitivity, response, and predictability."

42
The Washington Post has reported today that the Trump Administration is likely to pursue federal aid for U.S. shale fracking companies; which is not good news in the fight against the climate crisis.

43
I hope that attribution science keeps a close watch on all of the 'Climate Questions' cited in the linked article, so that it can provide us all with as early of a warning as practicable as to what is coming in the coming decades:

Title: "These Are the Biggest Climate Questions for the New Decade"

https://www.scientificamerican.com/article/these-are-the-biggest-climate-questions-for-the-new-decade/

Extract: "We asked climate researchers across a variety of disciplines about the biggest priorities and hottest topics for the 2020s. Here's what they said.

The Arctic is warming faster than anywhere else on Earth, with temperatures rising at least twice as fast as the global average. Many scientists believe that understanding the consequences of Arctic warming is essential for making accurate predictions about climate change around the world.

Accurately predicting the pace of future sea-level rise is one of the biggest priorities in climate science. And one of the biggest uncertainties about future sea-level rise is the behavior of the Greenland and Antarctic ice sheets, both of which are pouring billions of tons of ice into the ocean each year.

The past decade saw leaps and bounds in a field of climate research known as "attribution science" — the connection between climate change and extreme weather events.

Predicting how much the Earth will warm, given a certain level of greenhouse gas emissions, may seem like the simplest goal of climate modeling. But it's harder than it sounds.

Climate models don't always agree on the Earth's exact sensitivity to greenhouse gas emissions — although they do tend to fall within a certain range."

44
I concur with the linked article that climate scientists should make more use of empirical orthogonal functions (EOFs) when analyzing data to identify patterns and attribution.  Indeed, I recommend that this method be used more to identify/attribute ice-climate feedback patterns.

Title: "Why not use a clever mathematical trick?"

http://www.realclimate.org/index.php/archives/2020/03/why-not-use-a-clever-mathematical-trick/

Extract: "There is a clever mathematical trick for comparing different data sets, but it does not seem to be widely used. It is based on so-called empirical orthogonal functions (EOFs), which Edward Lorenz described in a Massachusetts Institute of Technology (MIT) scientific report from 1956. The EOFs are similar to principal component analysis (PCA).


The EOFs and PCAs provide patterns of spatio-temporal covariance structure. Usually these techniques are applied to datasets with many parallel variables to show coherent patterns of variability.

t is not that there is little use of EOFs (they are widely used), but the question is how the EOFs are used and how the results are interpreted. I learned that EOFs can be used in many different ways from Doug Nychka, when I visited University Corporation for Atmospheric Research (UCAR) in 2011.

The clever trick is to apply these techniques to data compiled from more than one source of data. When used this way, the technique is labelled “common EOFs” or “common PCA”.

Common EOFs are also particularly useful for quantifying local effects of global warming through a process known as empirical-statistical downscaling (ESD). It's pity that common EOFs aren't even mentioned in the recent textbook on ESD by Maraun and Widmann (2019)  (they are discussed in Benestad et al. (2008))."

45
AbruptSLR:
And Covid-19 is bad news even in the short term, because dropping GHGs will be immediately offset by dropping aerosols.

Tom,

I concur as I noted in my Reply #2750 which noted reductions in China's aerosol emission through February 10, 2020, and that if/when a pandemic were to occur the temporary reduction in global anthropogenic aerosol emissions would have a significant impact on GMSTA.  Also, I note that with the current world population of around 7.77 billion people, settlements are currently encroaching on wildlife also over the world and so in coming decades we can expect an increase in the transmission of contagious diseases from wildlife to humans, thus raising the risk of more pandemics in the future.

Best,
ASLR

46
The linked article makes the case that the COVID-19 outbreak is likely to be terrible new for the effective fight against climate chaos:

Title: "Why the coronavirus outbreak is terrible news for climate change"

https://www.technologyreview.com/s/615338/coronavirus-emissions-climate-change/

Extract: "It appears increasingly likely that the global coronavirus outbreak will cut greenhouse-gas emissions this year, as deepening public health concerns ground planes and squeeze international trade.

But it would be a mistake to assume that the rapidly spreading virus, which has already killed thousands and forced millions into quarantine, will meaningfully reduce the dangers of climate change.

As with the rare instances when worldwide carbon pollution dipped in the past, driven by earlier economic shocks, diseases, and wars, emissions are likely to rise again as soon as the economy bounces back. In the meantime, if the virus leads to a full-blown global pandemic and economic crash, it could easily drain money and political will from climate efforts.

In fact, we absolutely should dedicate the bulk of our international attention and resources to the outbreak at this moment, given the grave and immediate public health dangers.

Still, the fear is that the highly contagious coronavirus could complicate the challenges of climate change—which presents serious, if longer-term, threats of its own—at a point when it was crucial to make rapid strides. There are several ways this could happen:

- If capital markets lock up, it’s going to become incredibly difficult for companies to secure the financing necessary to move ahead with any pending solar, wind, and battery projects, much less propose new ones.

- Global oil prices took a historic plunge on Monday, driven by a price war between Russia and Saudi Arabia as well as coronavirus concerns. Cheap gas could make electric vehicles, already more expensive, a harder sell for consumers. It’s why Tesla’s stock crashed on Monday.

- China produces a huge share of the world’s solar panels, wind turbines, and lithium-ion batteries that power electric vehicles and grid storage projects. Companies there have already said they’re grappling with supply issues as well as declines in production and shipments, which have in turn slowed some renewables projects overseas. Any resulting clampdown on trade with the nation where the outbreak originated, which some members of the Trump administration are pushing for, will only further disrupt these clean-energy supply chain and distribution networks.

- Rising health and financial fears could also divert public attention from the problem. Climate change has become an increasingly high priority for average voters in recent years, and the motivating force behind a rising youth activist movement around the world, building pressure on politicians to take serious action. But in the midst of an economic downturn and public health crisis, people would understandably become more focused on immediate health concerns and pocketbook issues—i.e. their jobs, retirement savings, and homes. The longer-term dangers of climate change would take a back seat."

47
The linked article indicates that many food companies are overestimating the soil carbon sequestration benefits of their newly implemented regenerative agriculture initiatives.

Title: "The Limits of Soil Carbon Sequestration"

https://thebreakthrough.org/issues/food/carbon-farming

Extract: "Over the past six months, major food companies, like General Mills, Danone North America, Kellogg, and others, have launched efforts to cut their carbon footprint, in part by expanding the use of regenerative agriculture (also called carbon farming) practices.  Regenerative agriculture refers to an array of management practices — such as cover cropping, compost amendment, or grazing management — that sequester carbon in agricultural soils.

While these practices have positive soil health benefits, efforts to increase agricultural soil carbon sequestration likely don’t have nearly the level of expected climate benefits. Such poor carbon accounting means that corporations, governments, or individuals seeking to offset their greenhouse gas (GHG) emissions through regenerative agriculture are fooling themselves and the general public.

… mitigation through carbon capture — no matter if through reforestation, direct air capture systems, or soil carbon sequestration — should meet the standards of carbon accounting systems and carbon offset programs. That is, the sequestered carbon should be permanent and measurable, mitigation efforts should account for inadvertently increased emissions elsewhere, and organizations shouldn’t count mitigation that would have occurred in the absence of their efforts.

Current efforts to sequester carbon by expanding regenerative farming practices rarely meet these standards and therefore overestimate the amount of carbon sequestered. In other words, an estimated one ton of CO2 sequestered in agricultural soils is not the same as an emissions reduction of one ton of CO2. In fact, some types of soil carbon sequestration efforts actually risk increasing emissions. Companies and other organizations should acknowledge and address this in their GHG emissions reporting and climate efforts."

48
The linked reference (& associated linked article) indicates that there are two distinct atmospheric Rossby wave trains leading from the Equatorial Pacific Ocean to West Antarctica.  One wave train originates in the Western Equatorial Pacific and one originates in the Central Equatorial Pacific.  The first attached image shows panels a and c from Figure 1 of the linked reference while the second image shows panels b, d and c from Figure 1.

Kyle R. Clem et al, Role of the South Pacific Convergence Zone in West Antarctic Decadal Climate Variability, Geophysical Research Letters (2019). DOI: 10.1029/2019GL082108

https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2019GL082108

Abstract
Regional atmospheric circulation along coastal West Antarctica associated with the Amundsen Sea Low (ASL) mediates ice shelf melt that governs Antarctica's contribution to global sea level rise. In this study, the South Pacific Convergence Zone (SPCZ) is identified as a significant driver of ASL variability on decadal time scales. Using the Community Earth System Model, we impose a positive sea surface temperature anomaly in the SPCZ that reproduces an increase in convective rainfall in the southwest SPCZ that has been observed in recent decades, consistent with the negative phase of the Interdecadal Pacific Oscillation (IPO). Many of the major climate shifts across West Antarctica during the 2000‐2014 period when the IPO was negative can be explained via a teleconnection over the ASL emanating from the SPCZ. Knowledge of these relationships significantly enhances our understanding and interpretation of past and future West Antarctic climate variability.

Plain Language Summary
Heavy convective rainfall in the South Pacific Convergence Zone (SPCZ) alters the regional atmospheric circulation along coastal West Antarctica, impacting the regional climate and potentially driving warm ocean water upwelling that melts ice shelves. Increases in SPCZ rainfall cause cooling on the Antarctic Peninsula and warming across the Ross Ice Shelf and portions of East Antarctica. Such conditions were observed during the 2000‐2014 period in which the phase of the Interdecadal Pacific Oscillation, a naturally occurring mode of tropical Pacific decadal variability, was negative. The influence of the SPCZ on West Antarctic climate is consistent with observed shifts in West Antarctic climate over the period 2000‐2014. Therefore, the SPCZ, though a tropical climate feature, is found to be an important driver of West Antarctic climate on decadal time scales governed by the Interdecadal Pacific Oscillation.

Extract: "Our results show that the IPO teleconnection to West Antarctica comprises two distinct and competing tropically forced Rossby wave trains, one forced by the central equatorial Pacific and another by the SPCZ. Neither mechanism fully captures the observed circulation trends seen for 1999‐2014, but when examined together the net response is highly consistent with the observed circulation changes and the resultant post‐1999 reversal in West Antarctic climate trends, including both their spatial and seasonal variability."

Caption: "Figure 1. West Antarctic climate and SPCZ variability tied to low frequency tropical Pacific variability. (a) Annual‐mean (January‐December) time series of Antarctic Peninsula sea ice concentration averaged over 90‐46°W, 60‐72°S, normalized surface air temperature (SAT) anomalies averaged over five Antarctic Peninsula stations: Rothera, Vernadsky, Bellingshausen, Esperanza, and Marambio, Byrd station SAT (Bromwich et al., 2012), and Ross Ice Shelf SAT from ERA‐Interim averaged over 160°E‐156°W, and (b) map showing the study area and stations used for analysis: AP, Antarctic Peninsula; WAIS, West Antarctic Ice Sheet; RIS, Ross Ice Shelf; EAIS, East Antarctic Ice Sheet; DP, Drake Passage; BS, Bellingshausen Sea; AS, Amundsen Sea; RS, Ross Sea. (c) Annual‐mean (May‐April) time series of normalized Interdecadal Pacific Oscillation (IPO) index (multiplied by ‐1 for visual comparison) and annual‐mean SST anomalies in the southwest SPCZ (15‐25°S, 160‐175°E, region denoted by black box in (d) and (e)). (d and e) Observed annual‐mean (May‐April) linear trend (thin contours) of (d) ERSSTv4 tropical SST (°C/decade) and (e) ERA‐Interim tropical precipitation (mm · day‐1 · decade‐1 ) over 1979‐2014 capturing the IPO transition from positive to negative around 1999. Statistical significance of linear trends in (d) and (e) is shaded (reference color bar at bottom). Also given in (a) is the linear trend line in climate parameter over 1979‐1999 (red) and 2000‐2014 (blue), and in (d) and (e) the thick black line is the 4 mm/day precipitation climatology (1979‐2017) showing where on‐average there is deep tropical convection/ascent."

See also:

Title: "Warming waters in western tropical Pacific may affect West Antarctic Ice Sheet"

https://phys.org/news/2019-06-western-tropical-pacific-affect-west.html

Extract: "Warming waters in the western tropical Pacific Ocean have significantly increased thunderstorms and rainfall, which may affect the stability of the West Antarctic Ice Sheet and global sea-level rise, according to a Rutgers University-New Brunswick study.

Rutgers researchers studied how warming ocean temperatures in the western tropical Pacific influence weather patterns around West Antarctica. This century, the Antarctic Peninsula and interior West Antarctica have been cooling while the Ross Ice Shelf has been warming—a reversal of what happened in the second half of the 20th century. From the 1950s to the 1990s, the Antarctic Peninsula and interior West Antarctica were the most rapidly warming regions on the planet, and the Ross Ice Shelf was cooling.

The temperature trends flipped at the start of this century. Coinciding with the flip in West Antarctic temperature trends, ocean temperatures in the western tropical Pacific began warming rapidly. Using a climate model, the researchers found that warming ocean temperatures in the western tropical Pacific have resulted in a significant increase in thunderstorm activity, rainfall and convection in the South Pacific Convergence Zone. Convection in the atmosphere is when heat and moisture move up or down.

A rainfall increase in the zone results in cold southerly winds over the Antarctic Peninsula and warm northerly winds over the Ross Ice Shelf, consistent with the recent cooling and warming in those respective regions. So the West Antarctic climate, although isolated from much of the planet, is profoundly influenced by the tropics. The findings may help scientists interpret the past West Antarctic climate as recorded in ice cores."

49
For those who want to read about how some climate scientist feel about the current climate crisis, I provide the following linked to an article with many direct quotes:

Title: "'I'm profoundly sad, I feel guilty': scientists reveal personal fears about the climate crisis"

https://www.theguardian.com/environment/2020/mar/08/im-profoundly-sad-i-feel-guilty-scientists-reveal-personal-fears-about-the-climate-crisis

Extract: "Feelings of powerlessness and despair for the future are evident in letters written for a six-year ‘passion project’

Prof Katrin Meissner
How do I feel about it? I am still very worried. I am also profoundly sad. I am probably sadder than I was five years ago.

I feel powerless and, to a certain extent, guilty. I feel like I have failed my duty as a citizen and as a mother because I was not able to communicate the urgency of the situation well enough to trigger meaningful action in time.

What we are doing right now is an uncontrolled, risky experiment with the planet we live on."

50
While I don't have time to properly evaluate the linked reference which evaluates ENSO simulations by both CMIP5/PIMP3 and CMIP6; it seems to me that CMIP6/PMIP4 exhibits more skill in hind casting ENSO than CMIP5/PIMP3:

Brown, J. R., Brierley, C. M., An, S.-I., Guarino, M.-V., Stevenson, S., Williams, C. J. R., Zhang, Q., Zhao, A., Braconnot, P., Brady, E. C., Chandan, D., D'Agostino, R., Guo, C., LeGrande, A. N., Lohmann, G., Morozova, P. A., Ohgaito, R., O'ishi, R., Otto-Bliesner, B., Peltier, W. R., Shi, X., Sime, L., Volodin, E. M., Zhang, Z., and Zheng, W.: Comparison of past and future simulations of ENSO in CMIP5/PMIP3 and CMIP6/PMIP4 models, Clim. Past Discuss., https://doi.org/10.5194/cp-2019-155, in review, 2020.

https://www.clim-past-discuss.net/cp-2019-155/
https://www.clim-past-discuss.net/cp-2019-155/cp-2019-155.pdf

Abstract. El Niño-Southern Oscillation (ENSO) is the strongest mode of interannual climate variability in the current climate, influencing ecosystems, agriculture and weather systems across the globe, but future projections of ENSO frequency and amplitude remain highly uncertain. A comparison of changes in ENSO in a range of past and future climate simulations can provide insights into the sensitivity of ENSO to changes in the mean state, including changes in the seasonality of incoming solar radiation, global average temperatures and spatial patterns of sea surface temperatures. As a comprehensive set of coupled model simulations are now available for both palaeoclimate time-slices (the Last Glacial Maximum, mid-Holocene and Last Interglacial) and idealised future warming scenarios (one percent per year CO2 increase, abrupt four times CO2 increase), this allows a detailed evaluation of ENSO changes in this wide range of climates. Such a comparison can assist in constraining uncertainty in future projections, providing insights into model agreement and the sensitivity of ENSO to a range of factors. The majority of models simulate a consistent weakening of ENSO activity in the Last Interglacial and mid-Holocene experiments, and there is an ensemble mean reduction of variability in the western equatorial Pacific in the Last Glacial Maximum experiments. Changes in global temperature produce a weaker precipitation response to ENSO in the cold Last Glacial Maximum experiments, and an enhanced precipitation response to ENSO in the warm increased CO2 experiments. No consistent relationship between changes in ENSO amplitude and annual cycle was identified across experiments.

Caption: "Table 1: List of models included in study and length of simulations based on number of years of data available for NINO3.4 in the CVDP archive. Additional information about CMIP6/PMIP4 models (indicated in bold) is provided in the Supplementary Material."

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