Global warming discussion IV

[SusanB-M1]

Red Baron Farms and aleCcowaN

Many thanks for replies and links.

 

[Red Baron Farms]

Red Baron Farms and aleCcowaN

Many thanks for replies and links.

You are welcome. Getting through this thread is certainly daunting to be sure.

 

[Trakar]

Short of a melting East Antarctica ~7m is worst case, and that takes 200-500 years. Melting East Antarctica is 500+ years away even under some of the worst case warming scenarios and would progress at 2m-5m per 100 years. 50m isn’t impossible but it’s probably something on a 5000+ year time scale.

Got current, compelling, supportive references? Just because the first 5 meters may take another century to be realized, doesn't mean the second, (third, fourth, etc.) 5 meters will take that long.

 

[macdoc]

Consider tho the microclimate of East Antarctica means with a warmer and more moist atmosphere there is already evidence that ice is building faster than losses....given the current Milankovich position I think that will be very hard to dislodge as a limiting factor.

 

[Trakar]

Consider tho the microclimate of East Antarctica means with a warmer and more moist atmosphere there is already evidence that ice is building faster than losses....given the current Milankovich position I think that will be very hard to dislodge as a limiting factor.

Oh, I'm not expecting to be woken by an unexpected Antarctic tsunami. I do think, however, that 1-3 meters of sea level rise is a reasonable min. between now and the end of the 21rst Century, with a maximum likely in the 3-5 meter range, and in either case most of that rise will occur in the in the last 2-3 decades of the 21rst Century. If these expectations are met, I see no mechanism to brake the phenomena and prevent an accelerated level of rise in the 2-3 decades after the start of the 21rst century, and so on.

A few popsci references for the interested:

https://www.theguardian.com/environ...o-fast-whole-continent-may-be-at-risk-by-2100 - based on this study - http://www.nature.com/ngeo/journal/v8/n12/full/ngeo2563.html

https://www.pri.org/stories/2016-04-15/dont-let-antarcticas-size-fool-you-its-melting-faster-ever -based on these studies: http://www.nature.com/news/antarcti...2&spJobID=883880186&spReportId=ODgzODgwMTg2S0 - http://www.nature.com/news/antarctic-coast-meltdown-could-trigger-ice-sheet-collapse-1.18688 - http://www.nature.com/news/crucial-west-antarctic-glaciers-are-retreating-unstoppably-1.15202

https://www.nasa.gov/jpl/utexas-nasa-study-sees-new-threat-to-east-antarctic-ice
http://www.reuters.com/article/us-climatechange-antarctica-idUSKBN0DK0HM20140505

 

[macdoc]

Oh, I'm not expecting to be woken by an unexpected Antarctic tsunami. I do think, however, that 1-3 meters of sea level rise is a reasonable min. between now and the end of the 21rst Century, with a maximum likely in the 3-5 meter range, and in either case most of that rise will occur in the in the last 2-3 decades of the 21rst Century. If these expectations are met, I see no mechanism to brake the phenomena and prevent an accelerated level of rise in the 2-3 decades after the start of the 21rst century, and so on.

I concur but I expect zillch from East Antartic and lots from the West and Greenland and mid latitudes tho even there ..some glaciers in Alaska are growing.

Greenland has seen a couple of "entire land mass above freezing" days and with more of those and more of the melt lakes on the surface absorbing a lot of heat .....accelerated melting is certainly at hand.

East Antarctic might easily outlast humans given where we are in the Milankovic cycle.

http://www.universetoday.com/39012/milankovitch-cycle/

heading slowly towards a cooler regime. Still....that is a very slow cooling and we are making the heating off the charts.

Physics at the interface of glacier ocean and atmosphere are ...

 

[aleCcowaN]

A little number crunching says it all.

Imagine Antarctica is giving up yearly 10 times what she lost last year and take for that the upper limit of 600 km3 to do the calculation. Let's extend that loss to the 84 years left in this century, including 2017 (yes 2100 is still this century). That gives the oceans rising roughly 1.50 m. And this is an utterly exaggerated calculation no single serious -or less serious- model forecast in any logical scenario, as it implies Antarctica losing annually by 2100 an ice volume much larger than all the sea ice volume in the planet at any given date this year, requiring 2 x 10E21 Joules yearly just for melting it, which is a sixth of the energy imbalance of the whole planet today. And that just in ice melting at 0°C in restricted areas of Antarctica and its surrounding ocean, most of it during Summer, with peaks of 1.3 sv of melting streams, which compares with all the rivers in the planet together.

This should suffice to show the dangers of starting to compete about how many metres the oceans would rise by 2100. "2 metres" says one; "I think 3 to 5" says the other; "I remember some study [a much serious one, what else, otherwise the poster wouldn't remember it] saying 6 to 10", pretty much in the way of the conviction at the trial in The Last Remake of Beau Geste.

 

[aleCcowaN]

Congratulations! It's a boy!

Last week's indexes: 1-2 = +1.5°C; 3= +0.7°C; 4=-0.2°C; 3-4=+0.1°C

(hurricane season by the beginning of Autumn looks like it might be eventful on the Atlantic but not the Caribbean)

 

[Trakar]

A little number crunching says it all.

Imagine Antarctica is giving up yearly 10 times what she lost last year and take for that the upper limit of 600 km3 to do the calculation...

Why not simply look to the geological record comparisons to current conditions to perform such extrapolations?

While it is almost impossible to perform a one-to-one analysis (as there really is not a perfectly comparable geologic period), we can look at the peak melt rates during the Eemian and a few other interglacial periods and we can see that during the peak melt periods of these epochs the average peak rate of sea level rise seems to be about 1.2m/century. Our problem is that the current anthropogenic warming is to natural, cyclical, warming as steroidal induced competitive hypertrophic musculature development is to typical adolescent musculature development.

 

[Trakar]

Congratulations! It's a boy!

Last week's indexes: 1-2 = +1.5°C; 3= +0.7°C; 4=-0.2°C; 3-4=+0.1°C

[qimg]http://i63.tinypic.com/14djcsh.gif[/qimg]

(hurricane season by the beginning of Autumn looks like it might be eventful on the Atlantic but not the Caribbean)

That's not good news, I was really hoping for a brief respite, but we play the hand we're dealt.

 

[macdoc]

Oh no problem and one year "pause" ....

or is that one month....

I wonder if the RRR will return and dry California out ....the atmospheric river they are experiencing is a bit over the top.

 

[aleCcowaN]

Why not simply look to the geological record comparisons to current conditions to perform such extrapolations?

While it is almost impossible to perform a one-to-one analysis (as there really is not a perfectly comparable geologic period), we can look at the peak melt rates during the Eemian and a few other interglacial periods and we can see that during the peak melt periods of these epochs the average peak rate of sea level rise seems to be about 1.2m/century. Our problem is that the current anthropogenic warming is to natural, cyclical, warming as steroidal induced competitive hypertrophic musculature development is to typical adolescent musculature development.

But I see a problem with your reasoning. It's implied that quickly changing anthropogenic forcing can disrupt every level of the global system with a similar speed.

An extremely oversimplified comparison is thinking that doubling the voltage in a voltage step would speed up to a double the transient response of the circuit.

The truth is that the world deep ocean and the Antarctic ice blanket are dozens of levels away from any human harmful action, so they'll respond in their own time.

If you took all the waters in the hydrosphere and make a ball orbiting the earth, it would need to be just 2/3 of the Moon's distance to both be seen the same size. The deep reality is perceived just doing a little more of number crunching: if the current imbalance in the planet's energy budget was managed just by the oceans, their average temperature would rise 0.002°C per year! Of course the deep ocean may remain cool as a cucumber while AGW plays havoc with everything on the surface.

On the other hand, Antarctica not only has a location that has defined the global climate for million of years, but it also creates its own local conditions by a high plateau made of ice which is at points just 4 km away from the troposphere and remains weeks in the dark under clear skies. Constant blizzards are her best insulation.

Anything you can think attacking Antarctica's ice also provokes balancing responses: warmer weather melting the edges also increases the formation of new ice way above from the current 600-800 cubic kilometres per year.

There's no reason for expecting important differences in the rising of the oceans this time. Antarctica rules. What AGW is causing doesn't manifest there, and most, if not all, coral forming polyps together with half of sea life will vanish before any major coastal city and region needs to be evacuated. That is what humans are causing.

And that is my main objection about how AGW is deal with the public. I don't like deceiving them with tsunamis of ice cubes just because they're both mean and stupid enough as to not understand the consequences of their own actions. People who grew accustomed to earn more money each year not because of their ingenuity, just to invest the extra money in better food, clothes, trips and car and home air conditioning see no reason to do anything that deviate them from satisfying their needs and avoiding any adaptation, acclimatization included.

 

[aleCcowaN]

That's not good news, I was really hoping for a brief respite, but we play the hand we're dealt.

Now all ENSO indexes are in the positive.

And El Niño is premièring here, as usual, wet and with flash floods in the East, and desert-like dry and hot in the West: yesterday in Buenos Aires, heat point 105°F, and in some regions toward the Tropic of Capricorn it reached 118°F. In the west, real temperatures reaching 107°F.

 

[Pixel42]

NOAA's State of the Climate report for January is up:

The globally averaged temperature over land and ocean surfaces for January 2017 was 0.88°C (1.58°F) above the 20th century average of 12.0°C (53.6°F). This was the third highest January temperature in the 1880–2017 record, behind 2016 (highest) and 2007 (second highest).

From the same link:

According to NOAA's Climate Prediction Center, ENSO-neutral conditions were present during January 2017 and are favored to continue through the Northern Hemisphere spring (March–May) 2017.

 

[aleCcowaN]

From the same link:

That was a bit old. This week's report tells the same, however, as the constellation of models, both dynamic (half of them performing badly) and statistics (most of them performing horribly) still gave a 60% chance of ENSO neutral conditions for the Northern Spring.

I prefer to take advantage of CDAS (Climate Data Assimilation System) that offers reanalysis almost in real time, and follow the Niño 3.4 Index as if it's the stock market. It reached +0.78°C on 12z Feb 17, but it felt again to +0.03°C by 6z Feb 22 (11 hours ago). The last WWB is dissipating, but all models I trust, because of their previous performances, point towards a quick onset of El Niño conditions, in average by early July.

And most of all, the leak in my roof and my aching knee guarantee it .

 

[Trakar]

But I see a problem with your reasoning. It's implied that quickly changing anthropogenic forcing can disrupt every level of the global system with a similar speed.

An extremely oversimplified comparison is thinking that doubling the voltage in a voltage step would speed up to a double the transient response of the circuit.

Certainly, but, I don't see how the fact that we've gotten a lot better at our ability to tease out much finer scale discriminations in the data preserved in ice cores, is in anyway presuming this type of oversimplified comparison.
First, I'm not talking about estimating data based on theory, I'm talking about measurements of changes which occurred at the same regions over the same time frames under conditions of the same atm. partial pressures of GHGs and in general, the same global background setting. The only real difference is the rate at which we have climbed from atm. ppGHG min. to atm. ppGHG max. (it took the Eemian tens of thousands of years to transition from ppGHG min. to ppGHG max, whereas anthropogenic forcing has taken us from a point above the Holocene min. (probably close to the mid point between Holocene min. and max.) to a point near, if not already above, the (pre-Anthropocene) Holocene max. in around 2 centuries.

I understand the issues of thermal inertia implicit in the melting and freezing of huge masses water, I'm just not sure why I should look at the same area under greatly similar conditions, and expect one to be greatly different than the other in terms of how it reacts to those greatly similar conditions?

The truth is that the world deep ocean and the Antarctic ice blanket are dozens of levels away from any human harmful action, so they'll respond in their own time.

Geologic history seems to be indicating that while there definitely is some insulation of these deep systems from short-term superficial variation, they are not isolated, and they do interact, if in an admittedly more restricted fashion. Again, I'm not saying that we will be able to walk the Antarctic surface bedrock anytime within the next few millennia. What I am saying is that the geologic record provides us with ample evidence that an average of 1.2m of sea-level rise per century is the mean typical which should be expected for the current atm. ppGHG level we are at (~400ppm). Again that is the mean rate of sea-level rise in a fully mixed atmosphere at ~400ppm (the range for this period, if I recall correctly - I'll pull up the papers and check myself this weekend - runs from a significant fraction of a meter to around 4 meters/century).

If you took all the waters in the hydrosphere and make a ball orbiting the earth, it would need to be just 2/3 of the Moon's distance to both be seen the same size. The deep reality is perceived just doing a little more of number crunching: if the current imbalance in the planet's energy budget was managed just by the oceans, their average temperature would rise 0.002°C per year! Of course the deep ocean may remain cool as a cucumber while AGW plays havoc with everything on the surface.

Interesting, but I'm not sure of the relevance with regard to either polar ice sheet melt (Greenland and Antarctic) or the subsequent sea-level rise, at least with respect to anything anyone has stated or claimed,...so far.

On the other hand, Antarctica not only has a location that has defined the global climate for million of years, but it also creates its own local conditions by a high plateau made of ice which is at points just 4 km away from the troposphere and remains weeks in the dark under clear skies. Constant blizzards are her best insulation.

Anything you can think attacking Antarctica's ice also provokes balancing responses: warmer weather melting the edges also increases the formation of new ice way above from the current 600-800 cubic kilometres per year.

And there is compelling reason to think that this current situation is dramatically different than the conditions of the Eemian and (pre-Anthropocene) Holocene?

There's no reason for expecting important differences in the rising of the oceans this time.

That is what I have been saying




The only real difference I see is that there is no indication I've seen that we have done more than tap the brakes to make the taillights flash as we pass and leave 400ppm fading into the distance in the rearview mirror. I fully expect that we will reach 800ppm by 2100 and would not be terribly surprised if we surpassed 1000ppm especially if we start triggering any significant near surface carbon sinks to transition to releasing their carbon stores. There are fewer geologic examples of periods where atm. ppGHG concentrations were that high, and fewer proxies to look at to measure such issues in regard to sea-level rise, mainly because there is no ice on the planet that survived from those periods to examine.

 

[Trakar]

Oh for those who might enjoy a little (Winter/Summer) reading:

Ice Melt, Sea Level Rise and Superstorms: Evidence from Paleoclimate Data, Climate Modeling, and Modern Observations that 2°C Global Warming is Dangerous
https://arxiv.org/ftp/arxiv/papers/1602/1602.01393.pdf

This was an early version of the paper, but it is open-sourced
Going to this addendum published at http://csas.ei.columbia.edu/2016/03/22/abbreviation-of-ice-melt-paper/ will provide those interested with more supporting resources and information.

"Contribution of Antarctica to past and future sea-level rise" - http://www.nature.com/nature/journal/v531/n7596/full/nature17145.html
(Sorry no open-source link that I am aware of, I do have a copy of the paper for anyone that is interested in reading it. Shoot me a message either here or my email and I'll hook you up with a copy!)

From abstract - Polar temperatures over the last several million years have, at times, been slightly warmer than today, yet global mean sea level has been 6-9 metres higher as recently as the Last Interglacial (130,000 to 115,000 years ago) and possibly higher during the Pliocene epoch (about three million years ago). In both cases the Antarctic ice sheet has been implicated as the primary contributor, hinting at its future vulnerability...

YouTube discussion of above paper - https://www.youtube.com/watch?v=lUirD9HTpQg
(apologies for the way the information is presented).

Article discussing findings of this paper and other recent studies - http://www.nature.com/news/antarctic-model-raises-prospect-of-unstoppable-ice-collapse-1.19638

"Ocean Heat Drives Rapid Basal Melt of the Totten Ice Shelf" - (open Source) http://advances.sciencemag.org/content/advances/2/12/e1601610.full.pdf

"Sea-level rise due to polar ice-sheet mass loss during past warm periods" - (I also have a copy of this paper, am unsure about any open source link, I will be happy to forward a copy to any who send me an IM or email requesting a copy)

Abstract - Interdisciplinary studies of geologic archives have ushered in a new era of deciphering magnitudes, rates, and sources of sea-level rise from polar ice-sheet loss during past warm periods. Accounting for glacial isostatic processes helps to reconcile spatial variability in peak sea level during marine isotope stages 5e and 11, when the global mean reached 6 to 9 meters and 6 to 13 meters higher than present, respectively. Dynamic topography introduces large uncertainties on longer time scales, precluding robust sea-level estimates for intervals such as the Pliocene. Present climate is warming to a level associated with significant polar ice-sheet loss in the past. Here, we outline advances and challenges involved in constraining ice-sheet sensitivity to climate change with use of paleo–sea level records.

Enjoy, more available to the curious.

 

[aleCcowaN]

Certainly, but, I don't see how the fact that we've gotten a lot better at our ability to tease out much finer scale discriminations in the data preserved in ice cores, is in anyway presuming this type of oversimplified comparison.
First, I'm not talking about estimating data based on theory, I'm talking about measurements of changes which occurred at the same regions over the same time frames under conditions of the same atm. partial pressures of GHGs and in general, the same global background setting. The only real difference is the rate at which we have climbed from atm. ppGHG min. to atm. ppGHG max. (it took the Eemian tens of thousands of years to transition from ppGHG min. to ppGHG max, whereas anthropogenic forcing has taken us from a point above the Holocene min. (probably close to the mid point between Holocene min. and max.) to a point near, if not already above, the (pre-Anthropocene) Holocene max. in around 2 centuries.

I understand the issues of thermal inertia implicit in the melting and freezing of huge masses water, I'm just not sure why I should look at the same area under greatly similar conditions, and expect one to be greatly different than the other in terms of how it reacts to those greatly similar conditions?

Thermal inertia? Really?

You are educated enough in the specifics to understand that the speed of the ocean level rise isn't the first derivative of the GHG concentration in the atmosphere ... nor its second derivative ... nor its third or fourth.

That said, because it's painful to see such things written ... by you! ... you cannot ever have forgotten that now the general rise of temperatures is preceded by anthropogenic GHGs building up in the atmosphere, what I'm sure enough it's not the case with the Eemian and the like.

When a system is involved, even one several orders simpler than the Earth's climate, a mathematical representation in the form of a set of functions is not expected as the link between a changing parameter and any measure of the system's state. Let alone the link between GHGs and the melting of Antarctica.

How any system behaves, for instance, your body when you try to follow a diet to lose weight (I imagine you are thin, though ) provides enough foundation for anyone to understand that the real course of events lies somewhere in between a bootstrap-pulling response and no response at all, and as systems become larger and more complex more structural resistance to change is to be expected. Otherwise earthly evolution wouldn't have taken us where we are now.

Denialists have taken advantage of that to assert that AGHGs have nothing to do with the contemporary events regarding our climates. Why are we talking now in the other ridiculous extreme of imaginary consequences? Is the social scenery full of such helpless stupidity that we have to stoop to this? I know we have Trump now but in spite of that facto, is it?

[Later I'm replying to the rest of your message]

 

[Trakar]

Thermal inertia? Really?

Seriously? You want to wax poetically making nonsense analogies about all the waters of the Earth formed in a ball looking kinda sorta like it's the same size as the Moon if you squint your eyes, tilt your head just right and move it back and forth 10s of thousands of miles until you achieve the "proper" perspective (all of which has next to nothing to do with the issues being discussed), and you want to grief me for describing the latent heat of enthalpy when I chose to describe the fusion of ice in a more common parlance as thermal inertia,...Really?

Whatever.
Bless your Heart, and may you have a Good Evening.

...You are educated enough in the specifics to understand that the speed of the ocean level rise isn't the first derivative of the GHG concentration in the atmosphere ... nor its second derivative ... nor its third or fourth.

...you cannot ever have forgotten that now the general rise of temperatures is preceded by anthropogenic GHGs building up in the atmosphere, what I'm sure enough it's not the case with the Eemian and the like.

That is an over-simplification which more generally implies an incorrect understanding of both the Milankovitch mechanisms of action and what seems to be a mostly false understanding of how glaciations and deglaciations proceed.

During the (pre-Anthropocene) early Holocene episode -

...For example, the orbital cycles triggered warming at high latittudes approximately 19,000 years ago, causing large amounts of ice to melt, flooding the oceans with fresh water. This influx of fresh water then disrupted the Atlantic meridional overturning circulation (AMOC), in turn causing a seesawing of heat between the hemispheres (Shakun 2012).* The Southern Hemisphere and its oceans warmed first, starting about 18,000 years ago.* As the Southern Ocean warms, the solubility of CO2 in water falls (Martin 2005).* This causes the oceans to give up more CO2, emitting it into the atmosphere. The exact mechanism of how the deep ocean gives up its CO2 is not fully understood but believed to be related to vertical ocean mixing (Toggweiler 1999).
The outgassing of CO2 from the ocean has several effects.*The increased CO2 in the atmosphere amplifies the original warming. The relatively weak forcing from Milankovitch cycles is insufficient to cause the dramatic temperature change taking our climate out of an ice age (this period is called a deglaciation). However, the amplifying effect of CO2 is consistent with the observed warming.
CO2 from the Southern Ocean also mixes through the atmosphere, spreading the warming north (Cuffey 2001). Tropical marine sediments record warming in the tropics around 1000 years after Antarctic warming, around the same time as the CO2 rise (Stott 2007). Ice cores in Greenland find that warming in the Northern Hemisphere lags the Antarctic CO2 rise (Caillon 2003).

- excerpted from Skeptical Science with my apologies, as I don't have the time right now to provide a more proper exegesis of my apparently cultish fringe science understandings. I'll address the rest later, after I'm in a more relaxed and less hungry state of being.

 

[Trakar]

(apologies Alec my tone was improper)

BTW, I see I left the link off to the SS content: https://skepticalscience.com/print.php?a=7

apologies for the omission.

So, record low sea-ice and the dog days of "August" in the Antarctic (circa 2015) (lots of reports about this - https://public.wmo.int/en/media/press-release/wmo-verifies-highest-temperatures-antarctic-region )

I know Antarctic weather variations aren't high on most national priorities around the world, but how much would a couple of networks of a few hundred air-droppable, automated remote weather stations for the polar regions cost?

It seems counter-intuitive that it would take two years to cross-check and verify whether a record is actual or anomalous.