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Messages - AbruptSLR

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1
Yes but .
The error goes both ways .
You think because the models are not perfect you can discount the result .
Unfortunately there is plenty of evidence  that models underestimate the result of our unfortunate experiment in atmospheric physics.


Still think you should be banned for spreading denial  FUD .
 

2
That Stokes paper referenced in the conversation article is 

doi:10.1038/s41598-019-50343-5

open access. I have commented implications for Amery at

https://forum.arctic-sea-ice.net/index.php/topic,2578.msg232196/topicseen.html#msg232196

That paper references and earlier paper by Alley et al.  (doi: 10.1016/j.rse.2018.03.025 )  who evalued antarctic ice shelf vulnerability to hydrofracture. The measure of vulnerability is the fraction of ice saturated firn. I attach a figure showing that most ice shelves are vulnerable.

sidd

3
earlier today
Quote
"... If the higher CMIP6 ECS estimates hold true as the archive fills out, this will represent a departure from over four decades of research. Higher-sensitivity climates experience a greater probability of long-term temperature pauses and short-term trends, which can translate to more warming hiatuses or periods of fast temperature increase."
very interesting, indeed.  More data for deniers ("pauses") and then ghost-white faces.  :'(

4
Thanks for another nice selection of articles.

Enjoyed the animal ones and i cross posted the CAA glaciers (to What is new in the Arctic) and the Cerrado article.

5
The linked article explains how the current (and relatively rare) sudden stratospheric warming event over Antarctica can push cold air away from the surface ice.
Is the attached graph connected with the SSW? The EU severe weather site shows the area of the SSW moving over the S Pole in the coming days.

http://ds.data.jma.go.jp/tcc/tcc/products/clisys/STRAT/

6
I added fig 10 from Schroeder to the thwaites discussion thread. I attach here also.

sidd

7
The scientific method is the same regardless the phenomena. However it might be too late to define baseline and departure from baseline for a lot of ecosystems as they are changing rapidly.

8
Unfortunately the changes are faster than we can study them...

9
So Hawkins is redefining preindustrial to be 1720-1800 instead of 1850-1900. So of course it would show greater warming, but the underlying observations havent changed. That doesnt mean that sensitivity has gone up, it just means that we compare with a lower baseline.

One difficulty with Hawkins baseline is that measurements are scarcer the further back you go in time. So i can see why people use 1850-1900.

sidd

But Hawkins is working from a more sensible baseline because we know the the 1850-1900 period already includes human influences:

However, some anthropogenic warming is estimated to have already occurred by 1850 (Hegerl et al. 2007; Schurer et al. 2013; Abram et al. 2016) as greenhouse gas concentrations had started increasing around a century earlier (Fig. 1).

Sensitivity did not change but if you start from the wrong baseline it looks lower...


10
cross post (highlight added):  things are sometimes worse then modeled!
I think sometimes can replaced by usually.

It is just hard to accurately model the whole planet with many missing variables (trouble with clouds and many other things we just had not thought of before).

Once serious trouble in the Arctic was expected in the 2040s and nobody thought much about antarctica. Seemed to gain mass so probably ok for a long time after 2040.

Well that did not turn out to be true on both ends and i really can´t think of an example of a model that predicted things to be way worse.

First we are using a broad brush but we are painting the picture with missing details. So we did not know how warm the cold water coming up near the glaciers was or their topography which is relevant or the way they collapse.

And i think that rate of change is also doing something, maybe especially on land.

There was an interesting discussion in the science subforum about Tietsche et all 2011 and i read that paper then actually looked up the paper on the model they used. Lots of stuff in there. Quite detailed but so much is not in there.

The model mainly does land surface and temperatures and water level.

Every 20 years between 1980 and 2060, three such experiments are started in consecutive years (e.g., 2019,2020, 2021), so that we can analyze five different time slices with a three-member ensemble each.


What the model does not see is all the damage we do in the meantime (which is not that important for the paper i am quoting from but it is more important if you want to predict how much time we have to act.

So in between 1980 and now we have paved over many a grassland for parking lots and build many more roads. Added a couple of cities. Cut away some mangrove forests. Went fracking. Saw bark beetles eat whole forests. Indonesia had some nice fires while they were converting the local jungles to palm tree plantations. Now the Amazon is going to be a cattle ranch and then there is just the Congo left.

Basically you have to vary only some factors. But the models look at what current CO2 etc does in a natural world. It is a bit like the Houston 100 year flood maps. If you update the data you will get a refreshing new picture.

So basically the long term model is mostly run from the initial state while the changes between 1980 and now are quite large even if only looking at extra cities and decline of tropical forests.

Basic line: we are actively eating into all our carbon sinks so we might run out.

11
You didn't read the article. It is about how an increased vapor pressure deficit causes more water to be lost through the leaves, which causes plants to close their stomata to prevent water loss, which in turn reduces the amount of photosynthesis that takes place, so they grow more slowly. Nothing about the amount of water in total available to the plant.

12
The ozone hole has caused upper and middle stratospheric cooling which has contributed to the tightening of winds around Antarctica that led to the upwelling of CDW.

Of course, there are many other variables, but the damage to the ozone layer has cooled the stratosphere at both poles in the months of polar daylight.

13

I think if you really want to know where we are heading with emissions you simply have to follow the money, and investment banks have yet to actually stop funding oil, coal and gas infrastructure, and we have yet to control deforestation and industrial farming. It's not looking good.

That infrastructure has a long lead time to spend the money, 2 years or so, and then usually has a ROI over 10 years and thereafter it makes money. If the money is still flowing towards oil and gas how can we expect emissions to stop growing?

14
Those gravity studies of Antarctic geology are very interesting to me. It appears to me that the WARS is not inactive, but similar to the tectonic situation in the Arctic ocean where there's very slow spreading along ridge segments.

It's impossible to do typical GPS land based tectonic studies there because the ice moves much faster than the rifting. However, the ongoing volcanic activity, while not definitive, is evidence supportive of ongoing activity along the long rift/transform fault system that crosses Antarctica.

Of course, this tectonic situation is relevant to glacial melting, isostatic adjustment and sea level rise. This rift zone will be a potential region of increasing volcanism as glaciers retreat and depressure deep magma reservoirs. Yes, this is a potential positive feedback.

15
How hazardous algae blooms respond to changing oceans conditions may be illustrative of how microbial life responds. Here is an abstract for a webinar by Dave Hutchns that our ocean acidification group ( C-CAN )is sponsoring .
"How ocean acidification works hand-in-hand with warming and other global change stressors to promote toxic Pseudo-nitzschia harmful algal blooms along the West Coast
 
Toxic harmful algal blooms are an increasing problem globally, and the West Coast of the U.S. is no exception. In particular, massive neurotoxic blooms of the domoic acid-producing diatom Pseudo-nitzschia have recently appeared that are larger, more frequent, longer lasting, and much more toxic than any that have been historically recorded.  In recent years, these blooms have caused extensive damage to our Dungeness crab fishery, and they pose an increasing threat to other shellfish and finfish industries. It has become clear that this unprecedented intensification of toxic domoic acid events is very likely linked to ocean environmental change.  For instance, research in my laboratory has shown that ocean acidification can benefit the growth and increase the toxicity of many harmful algal bloom species, including Pseudo-nitzschia. At present day atmospheric CO2 concentrations, obtaining enough dissolved CO2 from the water to support growth can be a problem for Pseudo-nitzschia, which can thus be “carbon dioxide-limited”, and so it may actually directly benefit from higher CO2 levels. There is a definite potential for future CO2 fertilization of more frequent and more intense toxic algal blooms. However, we are now realizing that to understand and predict how ocean acidification will influence harmful algal blooms, we also need to consider a number of other interacting global change impacts. These other direct and indirect human disturbances include sea surface warming, losses of dissolved oxygen, stratification of the surface ocean, and modification of natural nutrient cycles by urban and agricultural pollution. For instance, in addition to ocean acidification, we have also shown that ocean warming strongly promotes domoic acid production by Pseudo-nitzschia.  I will discuss the complex network of interactions between ocean acidification and these many other global change multiple stressors that my lab group is currently working to understand, in order to help predict and perhaps mitigate the tremendously damaging toxic algal blooms that increasingly threaten our coastal fisheries and marine food webs."
 

16
A 2016 paper (Rising atmospheric methane: 2007–2014 growth and isotopic shift   -   summarizedhere) indicated the 2014 'large' increase in atmospheric methane appeared to be largely from tropical wetlands.  I couldn't find a more recent study of methane fingerprinting.

17
Which of course goes alongside this.

https://science.sciencemag.org/content/364/6440/548
Ocean winds blowing harder
Quote
Two frequently asked questions about how climate warming will affect the environment are whether windiness might change and what effects that might have on ocean waves. Young and Ribal analyzed global satellite data over the period from 1985 to 2018 to determine if there are any trends in oceanic wind speed and wave height. They found small increases in both quantities, with the strongest increases in extreme conditions and in the Southern Ocean. These findings are important for understanding air-sea exchange of energy and carbon dioxide and for projecting sea levels during storms.

Science, this issue p. 548
Abstract

In this study, global satellite data were analyzed to determine trends in oceanic wind speed and significant wave height over the 33-year period from 1985 to 2018. The analysis uses an extensive database obtained from 31 satellite missions comprising three types of instruments—altimeters, radiometers, and scatterometers. The analysis shows small increases in mean wind speed and significant wave height over this period, with larger increases in extreme conditions (90th percentiles). The largest increases occur in the Southern Ocean. Confidence in the results is strengthened because the wind speed trends are confirmed by all three satellite systems. An extensive set of sensitivity analyses confirms that both the mean and 90th percentile trends are robust, with only small impacts caused by satellite calibration and sampling patterns.

The higher sea states are  already impacting on west coast erosion rates here in NZ along with the anomalous regional rise in sea level.

18
James Hansen gave us an initial target of 350ppm for atmospheric CO2... Carbon capture is required and has been for well over a decade.

19
With sea level rise it will be higher storm surge that has significant impacts first.
We have already seen New York badly impacted with tropical cyclone  sandy.
It will not be the slow  rise of sea level that causes eventual retreat it will be weather events causing catastrophic damage and sane evaluation of the costs and futility of repeated repair. The developed world is far more susceptible to such costly events than the poor regions of Bangladesh.

Seeing as I have commented on this thread.
Thanks ASLR I have been reading your output for years and appreciate the immense amount of effort  your do in constructing your well supported narrative.

There are many factors contributing to inundation risks besides eustatic SLR, and storm surge, as illustrated by the attached three images.

Edit: I also note that recent research finds that for Hurricane/Typhoon cases, wave run-up is worse than previously assumed due to larger (than previously assumed) infragravity waves.

I would propose one small change to that first chart. Under tidal range, it suggests a "daily-yearly" cycle. Maximum tidal values occur during along an 18.6 year orbital cycle.  The cycle last peaked in 2015 and is declining. The next peak will be in 2034. King tides then in places like Miami Beach and Norfolk will be epic.

20
With sea level rise it will be higher storm surge that has significant impacts first.
We have already seen New York badly impacted with tropical cyclone  sandy.
It will not be the slow  rise of sea level that causes eventual retreat it will be weather events causing catastrophic damage and sane evaluation of the costs and futility of repeated repair. The developed world is far more susceptible to such costly events than the poor regions of Bangladesh.

Seeing as I have commented on this thread.
Thanks ASLR I have been reading your output for years and appreciate the immense amount of effort  your do in constructing your well supported narrative.

21

Title: "PP11A-05: Absence of the West Antarctic ice sheet during the last interglaciation" Carlson et al (2018)

https://agu.confex.com/agu/fm18/meetingapp.cgi/Paper/421418

Summary: "During the last interglaciation (LIG; ~129-116 ka), global mean sea level (GMSL) was >6 m above present. Based on evidence of only modest LIG Greenland ice-sheet retreat, Antarctic ice sheets may also have contributed to LIG GMSL, but direct data for a contribution is lacking. Here we investigate the LIG extent of the West Antarctic (WAIS) and Antarctic Peninsula (APIS) ice sheets using Sr-Nd-Pb isotopes of silt from ODP Site 1096 in the Bellingshausen Sea. Based on our shelf Sr-Nd-Pb provenance data and a stable-isotope age model, we document WAIS-APIS erosion of all radiogenically-discernable terranes from the latter part of marine isotope stage (MIS) 5 up through the Holocene, consistent with independent ice-margin chronologies showing ice presence on all of these terranes from MIS 2 through the Holocene. For the LIG/early MIS 5, we only find evidence of silt sourced from the erosion of the APIS and the mountain ranges that rim the northern modern WAIS, with an absence of silt from Pine Island glacier. Ice-sheet models link Pine Island glacier absence to full WAIS collapse into ice caps on mountains. Our record thus provides the first direct indication of a much smaller LIG WAIS, providing paleo-context for the susceptibility of the WAIS to collapse."

Some direct evidence of the collapse that is shown by the genetic distribution of octopi found in 2012.  At the time this was a primary indication that WAIS will collapse sooner under global warming than was thought at the time. 

https://www.sciencedaily.com/releases/2012/05/120509111453.htm
Scientists at the University have found that genetic information on the Antarctic octopus supports studies indicating that the West Antarctic Ice Sheet could have collapsed during its history, possibly as recently as 200,000 years ago.


Quote
Dr Phill Watts, from the University's Institute of Integrative Biology, explains: "We looked at information gathered by the Census of Antarctic Marine Life, which allowed us to examine genetic data on a scale that had not been done before in this area of the world. We expected to find a marked difference between Turguet's octopuses living in different regions of the ocean, particularly between areas that are currently separated by approximately 10,000km of sea. These creatures don't like to travel and so breeding between the populations in the Ross and Weddell Seas would have been highly unusual.

"We found, however, that they were genetically similar, suggesting that at some point in their past these populations would have been in contact with each other, perhaps at a time when the oceans were connected and not separated by the West Antarctic Ice Sheet. These findings agree with climate models indicating repeated periods in history when the climate was warmer, which would have released water from the ice and increased the sea levels, allowing dispersal of creatures between the Ross and Weddell Seas."

22
"While glaciovolcanism (defined as “the interactions of magma with ice in all its forms, including snow, firn and any meltwater”), may still be in its infancy; nevertheless, I provide the following links to relevant information (& two images about geomagnetism), and I note that there is more information in the 'Antarctic Tectonics' thread in the Antarctic folder; for those who are interested in learning more about this topic:

J.L. Smellie (2018), "Chapter 10 – Glaciovolcanism: A 21st Century Proxy for Palaeo-Ice",
Past Glacial Environments (Second Edition), Pages 335–375, https://doi.org/10.1016/B978-0-08-100524-8.00010-5

https://www.sciencedirect.com/science/article/pii/B9780081005248000105

Abstract: "Glaciovolcanism is a young science that has undergone a major transformation during the last 15 years. It is important for a variety of reasons but it is set to play a major role in deriving critical parameters of past ice sheets and thus greatly improve the accuracy of their reconstruction. Glaciovolcanic studies can deduce a wider range of parameters than any other methodology currently existing, including: establishing the presence of ice, its age, ice thickness, ice surface elevation, and basal thermal regime. These attributes can be acquired routinely for many glaciovolcanic sequences and, uniquely, several are quantifiable. Most glaciovolcanic terrains provide punctuated rather than continuous records of the coeval ice sheet, i.e., with numerous time gaps. Despite the gaps, glaciovolcanic studies of ice sheets have been completed successfully in the three major glaciovolcanic regions of the Earth: mainly Antarctica, but also Iceland and British Columbia (Canada). Future studies in these and other glaciovolcanic regions will considerably improve our knowledge of Earth’s water inventory and contribute to a better understanding of past ice dynamics and the impact of the cryosphere on global climate."

&

Title: "Antarctic Glaciovolcanism:

https://www2.le.ac.uk/departments/geology/people/smellie-jl/personal/ant-glaciovolc
A dedicated topic would be great, but where would it fit in?

Glaciovolcanism https://en.wikipedia.org/wiki/Glaciovolcanism

See attached image for potential glaciovolcanism hot spots, via 2018 REVIEW by Cooper etal. http://eprints.whiterose.ac.uk/124024/ . However, active faults possibly with submarine landslides could become apparent too, hence not only about volcanoes.

See my recent blog here with related studies Study: Enhanced Seismic Activity Observed in Alaska Due To Climate Change http://climatestate.com/2019/06/06/enhanced-seismic-activity-observed-due-to-climate-change/

Attempt to capture this topic in video format, for sources see http://climatestate.com/2019/06/08/video-enhanced-seismic-activity-observed-in-alaska-due-to-climate-change/


Maybe this terminology should be dubbed

Glacioseismicity.


23
Maybe not the first, being rich enough to postpone being hit before some poorer parts of the world. But we'll be hit eventually, or that risk seems substantial, at least.

24
Knowing how and knowing when: unpacking public understanding of atmospheric CO2 accumulation
https://link.springer.com/article/10.1007%2Fs10584-019-02423-8

One image split in two (snipped out the top and bottom parts) says it all (although current numbers are higher).

25
Roughly twelve years late or so... Remember beeing highly annoyed a decade ago about scientific reticence. Still someone told me just a few days ago, that I can't say that RCP2.6 is dead. A trip down memory lane:

Hansen on scientific reticence and sea level rise. (2007)
https://pubs.giss.nasa.gov/abs/ha01210n.html

Van Vuuren from 2007 (a paper preceeding the RCP2.6 one from 2011...).
Stabilizing greenhouse gas concentrations at low levels: an assessment of reduction strategies and costs
https://link.springer.com/article/10.1007%2Fs10584-006-9172-9

Adding Fig. 3:  Global CO 2 -eq. emissions (all sources) for the B2 baseline emission and pathways to stabilization at a concentration of 650, 550 and 450 ppm CO 2 -eq.

Edit; also adding Fig. 12 from the Van Vuuren 2011 paper. Emissions for the IMAGE (IM) alternative RCP scenarios.

26
Thanks again AbruptSLR for this research.

27
Crossposting this by ivica along with my comments.

An effort to raise public awareness about sea level rise, The Royal Institution, published on 2019-05-29, filmed at the Ri on 2019-02-11:

   Sea Level Rise Can No Longer Be Stopped, What Next? - with John Englander

   Q&A part
Thanks ivica.

Edit; What's not discussed in the future part at the end is sustainability and resource use. Nothing really new around SLR and glaciers (for those who follow this) but other than that, it's all sound and a worthwhile watch. Adding the key messages below.




28
Yup, and then we also have the worst and unfortunately still present hysteresis, maybe best depicted with Meadows bathtub analogy? First an old quote by Donella and then Dennis version from last year in one image.
http://donellameadows.org/archives/on-bathtubs-carbon-dioxide-and-disrespect/
Quote
–August 23, 1990–
...
The real issues here, the underlying fears that trigger our anger, are that on the one hand a bunch of environmental alarmists will force unnecessary changes in our fossil-fuel-powered way of doing things, and that on the other hand a bunch of technological conservatives with heavy stakes in fossil-fuel industries will drive the climate and the earth’s ecosystems into overheated chaos.

29
I just had a thought...
Could SLR (and other AGW effects) have a hysteresis? So say CO2e doubles (to 560 ppm) and these effects occur, then through superhuman effort we get the CO2e back down to 280 ppm, but the effects don't go back to "normal"?
I was looking at an ice shelf that collapsed, Larsens B I believe, and they said the last time their wasn't a shelf was something like 10,000 years ago. In some parts of the antarctic is over a mile thick! I would think some of that ice is much older. So any damage done is permanent in the short to medium term.

30
I just had a thought...
Could SLR (and other AGW effects) have a hysteresis? So say CO2e doubles (to 560 ppm) and these effects occur, then through superhuman effort we get the CO2e back down to 280 ppm, but the effects don't go back to "normal"?

31
Attaching the above paper.

32
This thread is about science, risks and reality Rich, then opinions.

<snip>
The recent SR 1.5 was a jolt which triggered a step up in activism with Greta, XR and the GND but it's not enough yet.
<snip>
I know we're going to figure this SLR shit out. I don't what the range is going to be, but when we do, it's probably going to impact financial markets that will impact billions of people.
<snip>
It's pretty much figured out already, apart from the replies posted above, you can also read what Rignot has published back towards 2013 regarding Antarctica, there's plenty of posts on that in here as well.
And Greta was talking before SR15 and XR, check the date here:

Another from the "We Don't Have Time" series (posted earlier in this thread).

A message to all adults out there who are busy defending an obsolete lifestyle.





Edit; added the quotes for clarity.

33
Rich, the real joke here is that there's little we can do to stop further melting glaciers even 200 years ahead. We can improve scientific projections of SLR but that's merely about when and how much.

We could step on the FF-brakes but few are interested. RCP2.6 is dead and this planet will go past two degrees like nothing since almost everything we build today are built using fossil fuels. Even if we succeed with a 100% PV/Wind/EV World, attitudes must change because we still can't create energy or the resources we need for maintaining our present lifestyles in the west (including current infinite growth mentality).

The only option left would be to cut back consumption and use renewables and the electric transports we can afford, as wisely as possible. And that's exactly what westerners don't want. That's also why we have a multitude of different failed incremental solutions and a new 2018 emissions record.

Adding an older comment of mine because I like this graph by Levermann.
It has no timescale, just temperature correlated to SLR.
http://www.pnas.org/content/110/34/13745.full.pdf
Fig 1E attached.
Quote
Paleo-Evidence
To compare the model results with past sea-level anomalies for
the temperature range up to 4 °C, we focus on three previous periods for which the geological record provides reasonable constraints on warmer climates and higher sea levels than preindustrial: the middle Pliocene, marine isotope stage 11, and the LIG (Fig. 1E).

34
We need to make changes today to stop worse things from happening further down the road and committing the system to Eemian era sea levels.

Rich, I suspect stopping Eemian sea levels is a train that has already left the station.

35
If someone would have told you 50 years ago how good we would become at predicting the path of a hurricane, you probably wouldn't have believed them.

We're going to get there with SLR.

Predicting the real time path of a hurricane involves understanding a number of small processes (wind sheer, water temperatures, location of lows, highs and fronts) in a very specific time frame. Predicting SLR involves understanding processes that are linked across the planet and occur over decades, an entire systems analysis. One is far more difficult than the other IMHO.

AbruptSLR's research rich posts here certainly demonstrate this complexity.

I visit this thread daily and always struggle to understand the research that AbruptSLR posts. If it were not for the abstracts and plain language summaries, it would be hopeless.

Did you even read my response?

This is a thread about sea level rise. I'm raising an important question about the science of predicting SLR.

Yes you are which is why I actually tried to draw a distinction between the degree of difficulty of understanding these two predictions.

I too value ASLR's contributions here and it is only because there is at least one such insightful and connected person on the topic that I ventured out to ask the question. It was a question which was hoping that there would be some expert insight in response.

We are certainly in agreement here as this is what I said about my reasons for visiting this thread daily.

Nothing personal, but you're not representing yourself as someone who has expertise to shed light on my question yet you are putting yourself in the position of being the arbiter of whether the question is a good one or not.

I am certainly not suggesting the question is not a good one and would not have tried to answer it if I thought this was the case.

Let me take a step back and explain why I'm asking the question. Humanity obviously needs this information to plan and to provide motivation to take action. It is only relatively recently (the past decade or so) that we really began to get understand the situation threat more clearly as being related warm ocean circulation reaching the ice sheets at depth.
 

Certainly understanding the impacts of oceans warming at depth is crucial but I am of the opinion there are also other crucial things we need to understand (in situ melt of the Greenland and Antarctic ice sheets, etc.) Many of these processes are also not clearly understood.

Regardless of opinion degree of difficulty, the reason we can track hurricanes more accurately is because we recognized it as a priority and applied ourselves to solving it.
 

Yes.

Predicting SLR will not be easy, but it is not an insurmountable task. As you indicate, the time dimension of prediction is completely different.
 

I did not say it was insurmountable. I, in fact, used the term "far more difficult" and, because of this, I do not think we are close to being able to accurately predict SLR. In fact, well informed scientists have very different estimates of SLR by the end of the century for this very reason.

IMO, this is a perfectly healthy and rational topic to inquire about and discuss, yet somehow I feel like I've triggered the ASIF culture police. If you don't like my question, why not just ignore it?

I actually liked your question which is why I responded. And my attempt to do so is certainly not "triggering the ASIF culture police". In the future, I will be more cautious and careful in responding to your posts. It was not my intent to offend.

36
We are in general, including the experts, notoriously overconfident and optimistic when it comes to predictions.

This article is from 1976, by E.C. Capen and the Society of Petroleum Engineers.
https://doi.org/10.2118/5579-PA
Quote
Handling Uncertainty

Our schooling trained us well to handle the certainties of the world. The principles of mathematics and physics work. In Newton's day, force equaled mass times acceleration, and it still does. The physicists, when they found somewhat erratic behavior on the atomic and molecular level, were able to solve many problems using statistical mechanics. The extremely large number of items they dealt with allowed these probabilistic methods to predict behavior accurately.

So we have a dilemma. Our training teaches us to handle situations in which we can accurately predict the variables. If we cannot, then we know methods that will save us in the presence of large numbers. Many of our problems, however, have a one-time-only characteristic, and the variables almost defy prediction.

You may embark on a new project whose technology differs from that used on other projects. Or perhaps your task is to perform a familiar project in a harsh environment. Try to estimate the total cost and completion time. Hard! You cannot foresee everything. And, for some reason, that which you cannot foretell seems to bring forth more ill than good. Hence, the predictions we make are often very optimistic. Even though we see the whole process unfolding and see estimate after estimate turn out optimistic, our next estimate more than likely will be optimistic also.

Also:
https://metasd.com/2012/07/capen-quiz/
Quote
Ventana colleague Bill Arthur has been giving the quiz to clients for years. In fact, it turns out that the vast majority of takers are overconfident in their knowledge – they choose ranges that are too narrow, and get only a three or four questions right. CEOs are the worst – if you score zero out of 10, you’re c-suite material.
  :)

37
Nice, thanks.
Posting this here as well, about DAC but it also outlines the risks and challenges for the US.
https://rhg.com/research/capturing-leadership-policies-for-the-us-to-advance-direct-air-capture-technology/

Last year, global CO2 emissions reached an all-time high. Recent scientific research indicates that global emissions need to reach net-zero between 2045 and 2055 to limit global temperature rise to 1.5 degrees Celsius. DAC technology does not make it possible to bypass the difficult work of reducing emissions. We find that even with break-neck electrification of vehicles, buildings, and industry, unprecedented improvements in energy efficiency, completely decarbonized power generation, and carbon removal from enhanced natural sequestration, DAC technology will be essential for the US to decarbonize by midcentury. Our analysis indicates that for the US to reach net-zero emissions by 2045 (our “100by45” scenarios) between 560 and 1,850 million metric tons of CO2 will need to be removed by DAC technology and then permanently stored underground annually, depending on the availability of other carbon removal options, such as bioenergy with carbon capture and storage (BECCS) and natural sequestration, and the pace of electrification in the transportation, buildings, and industrial sectors.

38
Levermann et al 2019 draft open for discussion, on Antarctic contribution to SLR:
https://www.earth-syst-dynam-discuss.net/esd-2019-23/

"For the so-called business-as-usual warming path, RCP-8.5, we obtain a median contribution of the Antarctic ice sheet to global mean sea-level rise within the 21st century of 17 cm with a likely range (66-percentile around the mean) between 9 cm and 36 cm and a very likely range (90-percentile around the mean) between 6 cm and 59 cm. For the RCP-2.6 warming path which will keep the global mean temperature below two degrees of global warming and is thus consistent with the Paris Climate Agreement yields a median of 13 cm of global mean sea-level contribution. The likely range for the RCP-2.6 scenario is between 7 cm and 25 cm and the very likely range is between 5 cm and 39 cm. The structural uncertainties in the method do not allow an interpretation of any higher uncertainty percentiles. We provide projections for the five Antarctic regions and for each model and each scenario, separately. The rate of sea level contribution is highest under the RCP-8.5 scenario. The maximum within the 21st century of the median value is 4 cm per decade with a likely range between 2 cm/dec and 8 cm/dec and a very likely range between 1 cm/dec and 13 cm/dec."

39
Slideshare by Glen Peters.
https://www.slideshare.net/GlenPeters_CICERO/were-so-fucking-late
Adding four selected images below.

40
Just a quick note on James Hansen and the carbon fee and dividend.

I spoke to James Hansen a few months ago by email, and he reiterated his belief that if countries began implementing a carbon fee and dividend, that the market would make the required adjustments.

I also note that Hansen talks quite a bit about "bullshit" (or greenwashing) in his book "Storms of My Grandchildren."

Please also note that when a carbon fee and dividend is brought in, it tends to come in at a price that is much lower than has been recommended, and is only slowly increased.

Finally, I note that Hansen wrote in 2008:

"If humanity wishes to preserve a planet similar to that on which civilization developed and to which life on Earth is adapted, paleoclimate evidence and ongoing climate change suggest that CO2 will need to be reduced from its current 385 ppm to at most 350 ppm, but likely less than that. The largest uncertainty in the target arises from possible changes of non-CO2 forcings."

The paper also warned that continued growth of greenhouse gas emissions for another decade would make it practically impossible to avoid catastrophic effects on the climate system.

Here we are in 2019, having seen another decade of growing emissions, with Mauna Loa CO2 readings recently cracking 415ppm.

Given all of this, while I have tremendous respect for Dr. Hansen, and continue to look to him as one of the most capable and astute climatologists, I can no longer agree with him that a carbon fee and dividend will be sufficient for us to avoid catastrophic warming.

Perhaps if the fee and dividend had been implemented across most of the world 20, or even 10 years ago. But how can we continue to advocate for a solution that, even if implemented tomorrow in most countries, would take 5 or so years -- assuming it was not full of loopholes -- to start working at all?

I believe, along with a growing number of people, that the only reasonable position to advocate for now is for a command economy, such as has occurred during the world wars. If climate change is an emergency, treat it like one. Don't tinker with the markets.


41
It's my experience so far in California that a 'carbon' tax isn't doing what it's supposed to do, and that is because the oil companies wont sell the farm. I am SERIOUSLY worried that the carbon tax will fail to cut emissions, here is NO guarantee it will work. We don't need some wishy-washy idea of tax and dividend that makes everyone seem like we are saving the planet but it turns out to be greenwashing.

My experience is that the LCFS carbon credits are trading at $183 a ton, and there is the ability to blend biodiesel to B20. If the oil companies wanted to be blending they would be. It's worth around $500m in tax credits. The problem is that all the WILLING participants in the market have already put in blending (6-7% of the market share). The oil companies want to keep selling their assets, the oil in the ground. They will NOT give up the share unless the marketing infrastructure changes. And they own it. If they aren't going to blend at $183 a ton, what chance is there of blending at $20 or $50. None. You have to compensate them for their lost assets, the billions of barrels in the ground, or they wont economically do it. They are businesses and beholden to their share holders.

What we need is a carbon market, and anybody adding GHG to the atmosphere through LUC, Burning Carbon, throwing nitrates on the soil, they have to match the emissions by buying carbon credits that are sequestered. lets start at 2% GHG sequestration, and devise a plan to get to %100 by 2050 using life cycle analysis and strong verification. It's the only way to be sure.

Also note, that means that everyone eating food or using power or gas is going to be responsible for paying to put the GHG back in the ground. We are all going to have to pay to do this. Thinking it can be revenue neutral and we wont have to pay for the environmental damage we are causing seems to be too good to be true. Rant Over






42
@AbruptSLR

Just watch for those two gaming strategies I outlined. To summarize, price controls are absolutely required or corporations will just gobble up those dividend cheques for themselves. And the large emitters must not be exempted from the tax, because that's the actual source of the money Hansen was eyeballing. Without them contributing to the tax, the dividend is a ridiculous pittance and not what Hansen envisioned at all.

You need price controls to protect the dividend cheque from being stolen, and large emitters participating in the tax in order to make the dividends large enough to matter.

Watch for it, because with those tiny changes, they've totally gamed it. Coming soon to an area near you!

43
Some people think that this thread is too doom and gloom;"
.
The truth of climate change is mostly gloomy. Someone has to tell the truth.

I value what I'm finding here.

BTW - the equations in that SLR paper on crevasses at Thwaites are way above my pay grade. I'll just infer that Thwaites is one of the prime spots where we'll see MICI proved or disproved in the intermediate future.

For what it's worth, I've watched a bunch of YouTube videos with Eric Rignot. He comes across as pretty credible and a good example of a scientist who is doing his best to wake people up.

44
Except you better watch closely how this tax is actually implemented in its details. In Alberta Canada, we have a carbon tax, but it wasn't implemented in line with Hansen's vision at all, where the taxing of large emitters would create a dividend so large that those households you mention would be able to buy solar panels and electric cars with it. Instead, the largest emitters are exempt from the tax and placed under the easily gamed cap and trade system, which has made the dividend cheque we receive pitifully small because the big money source Hansen was aiming at with his idea is exempt, which effectively negates Hansen's concept.

Then, what's happened on top of all that, is that the energy companies have all still cried wolf politically, about a tax which they are actually exempt from, and raised their prices beyond even what those small dividend cheques provided to families, effectively hoovering up all those cheques from the households and placing them into their own pockets instead.

The devil is in the details. In Alberta, the tax has left households net poorer, and in even less of a position to buy alternatives.

Hansen envisioned a culture that actually wanted to solve climate change. He forgot to account for the psychopaths that run and game the system, who are finally only now going to implement the tax because all the Davos people got together and figured out how to game it. Just because they're calling it a carbon tax and dividend program, doesn't mean it's Hansen's vision. All they've done is figured out how to game it is all. Nobody in Alberta's contracting economy is able to buy a solar panel or an electric car with the $120 dollars every three months that we get, especially when our energy costs, overt and hidden, just went up by four times that amount by the companies who don't even pay the tax. It's a total fail here because it was gamed to change Hansen's vision into something he wasn't envisioning at all, which is what corporations and their governments do with ideas.

The devil is in the details.

45
Glacial cycles simulation of the Antarctic Ice Sheet with PISM – Part 1: Boundary conditions and climatic forcing.
https://www.the-cryosphere-discuss.net/tc-2019-71/

Glacial cycles simulation of the Antarctic Ice Sheet with PISM – Part 2: Parameter ensemble analysis.
https://www.the-cryosphere-discuss.net/tc-2019-70/

Reference PISM simulation of the Antarctic Ice Sheet over the past 210 kyr, mp4 at this link:
https://av.tib.eu/media/41779

46
Thank you ASLR. I'll spend some time reading this.

47
Adding to ASLR's post above, an mp4 I made of the NASA animation attached below.
Quote
Changes in surface height at Thwaites Glacier's grounding line, 2011 to 2017, with sinking areas in red and rising areas in blue. The growing cavity (red mass, center) caused the greatest sinking. The mottled area (bottom left) is the site of extensive calving. Contours show bedrock topography. Credit: NASA/JPL-Caltech

Also, AGGI is now updated with 2018 numbers:
https://www.esrl.noaa.gov/gmd/aggi/aggi.html

Edit; mp4 messed up so I had to redo it.

48
v_m, LvdL already posted that twice in here.

Edit; adding this tweet by Aslan Grinsted and the graph for RCP8.5 (RCP4.5 in the tweet).
https://twitter.com/AGrinsted/status/1130819798634573824

49
Sea Level Rise Could Be Much Larger Than Expected 
https://www.bbc.com/news/science-environment-48337629

Scientists believe that global sea levels could rise far more than predicted, due to accelerating melting in Greenland and Antarctica,

The long-held view has been that the world's seas would rise by a maximum of just under a metre by 2100.

This new study, based on expert opinions, projects that the real level may be around double that figure.

In the researchers' view, if emissions continue on the current trajectory then the world's seas would be very likely to rise by between 62-238cm by 2100. This would be in a world that had warmed by around 5C - one of the worst case scenarios for global warming.

"For 2100, the ice sheet contribution is very likely in the range range of 7-178cm but once you add in glaciers and ice caps outside the ice sheets and thermal expansion of the seas, you tip well over two metres," said lead author Prof Jonathan Bamber from the University of Bristol.

... According to the authors, this scenario would have huge implications for the planet.

They calculate that the world would lose an area of land equal to 1.79 million square kilometres - equivalent to the size of Libya.

Much of the land losses would be in important food growing areas such as the delta of the Nile. Large swathes of Bangladesh would be very difficult for people to continue to live in. Major global cities, including London, New York and Shanghai would be under threat.

"To put this into perspective, the Syrian refugee crisis resulted in about a million refugees coming into Europe," said Prof Bamber.

"That is about 200 times smaller than the number of people who would be displaced in a 2m sea-level rise."


----

Ice sheet contributions to future sea-level rise from structured expert judgment 
https://www.pnas.org/content/early/2019/05/14/1817205116

50
How far are we away from proof of concept with MICI? It seems like we are making heaps of progress with measuring the topography beneath the ice and water temperature / salinity / depth.

I'm anticipating the day when scientists can tell us that a specific retrograde grounding line has been breached and warm water is at the base of an 800+ meter deep ice cliff so we can all follow along in real time.

Correct me if I'm wrong, but I think MICI would be a function of the speed at which the warm water lifts the ice off the bedrock. The surface ice instability kicks in when the base begins to float, no?

I realize that these are very remote places which makes observation challenging but there is also huge public interest. Any ice gurus know when we'll hit an important grounding line?

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