When will the Arctic Ocean (CAB) go Ice Free in Winter?

[Stephan]

...
PIOMASS winter volume is around 20000 cubic Km. It's reducing at 3100 cubic Km per decade. That gives us about 70 years before the Arctic is ice free in winter.

...and if you assume that the trend is not linear but slightly exponential you reach that ice-free state 6-8 years earlier (see the table I posted a couple of days ago) and thus BEFORE 2100.

[magnamentis]

...
PIOMASS winter volume is around 20000 cubic Km. It's reducing at 3100 cubic Km per decade. That gives us about 70 years before the Arctic is ice free in winter.

...and if you assume that the trend is not linear but slightly exponential you reach that ice-free state 6-8 years earlier (see the table I posted a couple of days ago) and thus BEFORE 2100.

and i expect a logarithmic development due to the location of the ever smaller amount of remaining ice where it will be more difficult to melt not easier, hence a slow down, not an acceleration is what i see coming, i for one probably won't see which is true

[GoSouthYoungins]

I'm sure the model programmed by Arctic experts does a better job of predicting the influence of the cold halocline on sea ice than the guesses of members of this forum.

I'm not saying modeling is a pointless endeavor ( look at Adriana Lima for example ). But they seem to systemically conservative.  They have been around for long enough that we can check their veracity. Every model I know of considered 2007 and 2012 arctic ice extents outside the bounds of possibility. Same for the global sea ice extent in 2016 and 2017. Same for temperature in 2014, 2015, 2016. So if the models always show things as more stable than reality, it should follow that when you look at model predictions you go "hey, reality is probably a lot less stable than these models are prediction" and not "hey, this model says the system is stable, so I believe it."

If there are model prediction from this millennium, which have turned out to show climate systems as less stable than they have proven to be, please share them with me.

[gerontocrat]

Lets assume that trend is linear.

But perhaps let us not ?

[Dharma Rupa]

Gerontocrat
I really like your message. It is spot om.

Palaeontology is not the answer.

Paleontology and the models reinforce one another. Both together in context are more skillful than either alone.

The models all want continuous change, the evidence is that change has been discontinuous.  Until you offer a model that both seems to handle Historical data and the sudden changes which seem to have happened I am disinterested in them -- and I only really ask that they have some demonstrated skill (which they do not).   But absent predictions of sudden changes, I think the models can be completely ignored.

[jai mitchell]

2065

[Michael Hauber]

How many centuries does paleontology tell us it took to go ice free last time the earth was this warm and warming at this rate?

How warm was it last time paleontology told us it was ice free in winter?  I could look it up myself, but maybe those who want to appeal to paleontology should do the work?  Also +x degrees at equilibrium will be different from +x degrees while rapidly warming.  During rapid warming the land warms significantly faster than the ocean surface, and the ocean surface warms faster than the subsurface.  Both will make a big difference as to whether the ocean can resist several months of winter darkness/cold without freezing.  Arctic ocean surface might be an exception, but moreso in summer.  Outside Arctic is still going to warm slower than land and make a difference to how much heat is brought in by currents.

[Dharma Rupa]

How many centuries does paleontology tell us it took to go ice free last time the earth was this warm and warming at this rate?

Seems to me there have been a number of papers indicating sea level changes in the tens of meters in less than a decade.  If you think sea level can rise 30 feet and the Arctic still be ice covered.....

[deconstruct]

Linearly extrapolating "winter" (April) maximum volume would have the trend line hitting zero in about 2100. September trend would hit zero about 2035. It's not a huge mental leap to figure that once there is no ice to melt, that warming would go into the ocean and start subtracting from the winter maximum. So that would bring winter BOE to about 2070.

Aehm.. you are aware that it doesn't work like that?
The current winter ice loss is nearly completely in the peripheral areas, not in the CAB. And that is the easy to melt (or not-to-regrow) ice, because it is right on the edge, where temperatures are so high, that there already was the border between ice-free and ice-covered in winter.

The central CAB is about 20°C *colder* than that, so there is no way, that there will not be ice growth in the winter, even in 2100 or 2200. The only possibility that this will happen is, if there happens something extraordinary, but that is naturally not infered from linear extrapolation (or any sort of extrapolation).

And as long as temperatures are cold enough - ice will form. There will be half a year no sun and that won't change, no matter what. Even in mid-latidudes lakes freeze in winter or seas like the Baltic still grow a (small) ice cover. And it is *much much* warmer there than at the North Pole.

So IMO it is completely unrealistic to expect that there will be no ice growth in winter in the central Artic. And off course Volume can be much, much lower than today, and still there will be like 3-4 million square km of winter sea ice. If you have now a 1m thick layer of ice and in 2100 it will only grow to 10 cm thickness in winter, it will be only 10% of the volumen, despite having still a considerably large extent.

So no, for the question if there will be ice growth in winter  in the Arctic, volume is not the best metric.

[deconstruct]

Seems to me there have been a number of papers indicating sea level changes in the tens of meters in less than a decade.  If you think sea level can rise 30 feet and the Arctic still be ice covered.....

Please, name one paper that claims that in a respected journal!

And of course not counting events like a big asteroid hitting Antarctica which instantly melts most of it, but climatic events.

The total *possible* sea level rise (i.e. all of Greenland and Antarctica melts) holds around 65
meters of sea level. To melt "tens of meters in less than a decade", would mean that you would melt *all* of Antarctica and Greenland in just 10 years.

That is totally unplausible and just nuts...

I can only repeat myself... The claims in this forum get crazier and crazier...

[RoxTheGeologist]

Yes, of course, if it remains at -20°C and that the AML survives.

There is evidence that you start to get 1000m convection cells forming when the AML breaks down, say because of the lack of summer ice, and that would certainly cause enough heat to be transported to the cloudy dark rainy Arctic to keep it ice free.

https://link.springer.com/article/10.1007/s00382-017-3849-9

Reduce the FDD days enough, add enough heat in the atmosphere and the ocean and add convection to the top 1000m of the Arctic? Perhaps that would be enough heat to keep it ice free during the long cold Arctic night. 

[Dharma Rupa]

Yes, of course, if it remains at -20°C and that the AML survives.

There is evidence that you start to get 1000m convection cells forming when the AML breaks down, say because of the lack of summer ice, and that would certainly cause enough heat to be transported to the cloudy dark rainy Arctic to keep it ice free.

https://link.springer.com/article/10.1007/s00382-017-3849-9

Reduce the FDD days enough, add enough heat in the atmosphere and the ocean and add convection to the top 1000m of the Arctic? Perhaps that would be enough heat to keep it ice free during the long cold Arctic night.

You only need enough convection to well mix the top 100M of the ocean.  There is already plenty of heat there.

[GoSouthYoungins]

The central CAB is about 20°C *colder* than that, so there is no way, that there will not be ice growth in the winter, even in 2100 or 2200. The only possibility that this will happen is, if there happens something extraordinary, but that is naturally not infered from linear extrapolation (or any sort of extrapolation).

If you expect everything to stay ordinary for the next 200 years, um why? Are you aware that our current GHG levels are extraordinary and it is causing extraordinary warming but its just getting started.  The last time GHG levels were this high, the arctic was ice free. So relative these GHG levels, it would actually be pretty ordinary for the arctic to be ice free.

[josh-j]

Things won't stay ordinary. But that doesnt mean things will change in the way you expect either. We all know the trends but this is a complex system. I'm sure something dramatic could happen that gives us a winter BOE but that doesnt mean it will happen any time soon. It might be reasonable to predict it as a possibility but not assume it is near-certain to happen within a few decades.

[Michael Hauber]

Yes, of course, if it remains at -20°C and that the AML survives.

There is evidence that you start to get 1000m convection cells forming when the AML breaks down, say because of the lack of summer ice, and that would certainly cause enough heat to be transported to the cloudy dark rainy Arctic to keep it ice free.

https://link.springer.com/article/10.1007/s00382-017-3849-9

Reduce the FDD days enough, add enough heat in the atmosphere and the ocean and add convection to the top 1000m of the Arctic? Perhaps that would be enough heat to keep it ice free during the long cold Arctic night. 

How long will that take?.  Also consider shallow shelves on Laptev  Convection and warm currents might maintain ice free at north pole right through winter, but Laptev being shallow and protected from warm currents, and adjacent to cold land mass will take longer.  Consider current situation in Antarctica and north Pacific.  What is AML?  Something to do with stratification of Arctic?  Antarctica and North Pacific don't have this and manage to get ice in winter.  Just needs to be cold enough, so it depends on how long it stays cold enough.  Judging by model projections I'd say best guess is it will stay cold enough for centuries.

[magnamentis]

How many centuries does paleontology tell us it took to go ice free last time the earth was this warm and warming at this rate?

Seems to me there have been a number of papers indicating sea level changes in the tens of meters in less than a decade.  If you think sea level can rise 30 feet and the Arctic still be ice covered.....

arctic sea ice has no impact on sea-level talking about that in this thread (arctic ocean)

[Shared Humanity]

Lets assume that trend is linear.

But perhaps let us not ?

None of the trends related to AGW are linear. I would welcome someone posting one that is so that I can stand corrected.

[Shared Humanity]

How many centuries does paleontology tell us it took to go ice free last time the earth was this warm and warming at this rate?

Seems to me there have been a number of papers indicating sea level changes in the tens of meters in less than a decade.  If you think sea level can rise 30 feet and the Arctic still be ice covered.....

An ice free Arctic Ocean by itself has no impact on sea level rise and what papers are predicting sea level rise of tens of meters in less than a decade?

I am having a hard time following this conversation. It's as if everyone is talking past the others.

[GoSouthYoungins]

How many centuries does paleontology tell us it took to go ice free last time the earth was this warm and warming at this rate?

Seems to me there have been a number of papers indicating sea level changes in the tens of meters in less than a decade.  If you think sea level can rise 30 feet and the Arctic still be ice covered.....

An ice free Arctic Ocean by itself has no impact on sea level rise and what papers are predicting sea level rise of tens of meters in less than a decade?

I am having a hard time following this conversation. It's as if everyone is talking past the others.

Ice free arctic wouldn't directly have an effect on sea level, but greenland melt would probably go into overdrive. Maybe there would be more snow too but melt would probably overwhelm a snow increase.

I agree, we are all talking past each other. I think it speaks to the complexity of the issue. The weight each person puts on different factors.  There really is no way to definitively prove the impact of any given component. Uncharted territory.  This is why I find proclamations that certain things WILL BE a certain way decades or centuries in the future quite annoying.

[El Cid]

"This is why I find proclamations that certain things WILL BE a certain way decades or centuries in the future quite annoying."

Couldn't agree more!

[kynde]

Judging by model projections I'd say best guess is it will stay cold enough for centuries.

You can't really use contemporary models which are used to model present situation to make multi century projections. The temperature is heavily coupled to the assumption of ice presence, and that cannot be used to predict continued ice presence without circular reasoning. The odds of game changing forcings to manifest this century are simply too much.

It was already stated how models, while currently exhibiting our best scientific knowledge of arctic climate, are not tuned for the changes that are in the pipeline which are largely unknown. What seasonally ice free arctic and narrowing temperature difference will do to the northern hemisphere climate is largely unknown. And _that_ is happening well within century scale.

Now, just to be clear. I'm not saying one way or another about how cold it will stay up north in the years to come,  I'm just strongly opposed to using current models to project "centuries" given that we can't really claim to even know what's going to happen with the seasonally ice free arctic in the decades after. And as a result, how could the models do any better?

Your qualitative arguments about Laptev shallowness etc make a better argument.

[Michael Hauber]

I'm just strongly opposed to using current models to project "centuries" given that we can't really claim to even know what's going to happen with the seasonally ice free arctic in the decades after. And as a result, how could the models do any better?

Multi-century model projections are obviously problematic.  Is there a better alternative?  (I don't think so)  Or do we just avoid talking about the issue altogether?

[Dharma Rupa]

...Also consider shallow shelves on Laptev  Convection and warm currents might maintain ice free at north pole right through winter, but Laptev being shallow and protected from warm currents, and adjacent to cold land mass will take longer...

Please see the first post in this thread, as the question was only about the Central Arctic Basin.

[Dharma Rupa]

How many centuries does paleontology tell us it took to go ice free last time the earth was this warm and warming at this rate?

Seems to me there have been a number of papers indicating sea level changes in the tens of meters in less than a decade.  If you think sea level can rise 30 feet and the Arctic still be ice covered.....

An ice free Arctic Ocean by itself has no impact on sea level rise and what papers are predicting sea level rise of tens of meters in less than a decade?

I am having a hard time following this conversation. It's as if everyone is talking past the others.

e.g.

https://www.scientificamerican.com/article/oceans-can-rise-in-sudden-bursts/

[Tor Bejnar]

…
Seems to me there have been a number of papers indicating sea level changes in the tens of meters in less than a decade.  If you think sea level can rise 30 feet and the Arctic still be ice covered.....

An ice free Arctic Ocean by itself has no impact on sea level rise and what papers are predicting sea level rise of tens of meters in less than a decade? …

e.g.  https://www.scientificamerican.com/article/oceans-can-rise-in-sudden-bursts/

From that SA article:

Scientists already knew this was a time marked by significant sea-level rise. But the existence of the terraces suggests, for the first time, that the process was not gradual, but rather occurred in sharp, sudden bursts. In fact, the terraces suggest several meters of sea-level rise may have occurred on the scale of just decades during this time.

That is, meters per decades, not 10s of meters per decade.  That's about half an order of magnitude difference on each side of the 'per', making the original ascertain an exaggeration by about a factor of 10.   (Yes, this is just one publication, but I think others will duplicate this 'fastest SLR' rate, outside of breached 'dams' - e.g., Mediterranean & Black Sea.)

But this is OT as to the CAB surface going 'black' in the winter due to climate change.

[Dharma Rupa]

But this is OT as to the CAB surface going 'black' in the winter due to climate change.

True, but my point is that people are proclaiming Truth when it isn't even yet clear they are working with a viable Theory.

I'd like to hear suggested mechanisms, not obeyance to the Great Modelling Gods.

[Michael Hauber]

But this is OT as to the CAB surface going 'black' in the winter due to climate change.

True, but my point is that people are proclaiming Truth when it isn't even yet clear they are working with a viable Theory.

I'd like to hear suggested mechanisms, not obeyance to the Great Modelling Gods.

Strawman.  Models are not truth, no one has claimed that they are.

I'd say anyone who think that Arctic ice can disappear this century during winter lacks a viable theory and the challenge is to come up with a better method than the models of predicting future sea ice conditions.

[Dharma Rupa]

But this is OT as to the CAB surface going 'black' in the winter due to climate change.

True, but my point is that people are proclaiming Truth when it isn't even yet clear they are working with a viable Theory.

I'd like to hear suggested mechanisms, not obeyance to the Great Modelling Gods.

Strawman.  Models are not truth, no one has claimed that they are.

I'd say anyone who think that Arctic ice can disappear this century during winter lacks a viable theory and the challenge is to come up with a better method than the models of predicting future sea ice conditions.

I don't know when the CAB will be ice-free in Winter.  I just think it will happen suddenly, and at about the same time it is ice-free in Summer.  The areas close to the continents are going to probably take longer.

I do think that any claim to knowing when is pure bullshit.

[Shared Humanity]

This thread had promise. It has devolved into a distraction. Carry on.

[magnamentis]

But this is OT as to the CAB surface going 'black' in the winter due to climate change.

True, but my point is that people are proclaiming Truth when it isn't even yet clear they are working with a viable Theory.

I'd like to hear suggested mechanisms, not obeyance to the Great Modelling Gods.

Strawman.  Models are not truth, no one has claimed that they are.

I'd say anyone who think that Arctic ice can disappear this century during winter lacks a viable theory and the challenge is to come up with a better method than the models of predicting future sea ice conditions.

I don't know when the CAB will be ice-free in Winter.  I just think it will happen suddenly, and at about the same time it is ice-free in Summer.  The areas close to the continents are going to probably take longer.

I do think that any claim to knowing when is pure bullshit.

to have an opinion based on an educated guess is sometimes less "BS" as you name things than bringing up utterly non-sensual stupid ideas, camouflage it with "i don't know but i think" and then discredit anyone else who has a valid point but can't provide proof because things lay so far in the future.

you're posts are very close to be trollish IMO and sooner or later others will stumble upon and recognize it.

IMO you are the one with a dedicated bias that quite often lacks any common sense and react very aggressively when others show traces of annoyance about it and/or surprise as to how someone can genuinely believe that the arctic ocean or the CAB will once of a sudden become ice-free in winter soon. we're not even close to being ice-free in summer.

after all this planet's poles definitely look away from the sun in winter and no-one can tell me that we shall "suddenly" and "soon" see a 20-30C plus in winter across the board and permanently. not even places in mid latitudes that after all some claim to release sufficient heat into the arctic, sufficient to remain ice-free during winter, are currently warm enough for such events.

and i'm fully aware that the gulf-stream keeps parts of the arctic ice-free in winter but this is neither
the CAB yet nor can one warm inflow keep it's heat across the entire arctic any time soon. it will cool down as it does now and eventually be neighboured by colder regions. that will freeze, no matter which parts won't freeze in a few decades.

[oren]

I don't know when the CAB will be ice-free in Winter.  I just think it will happen suddenly, and at about the same time it is ice-free in Summer.  The areas close to the continents are going to probably take longer.

I do think that any claim to knowing when is pure bullshit.

I agree with your first statement, but most certainly don't agree with the second. Every arctic location that has transitioned from perennial ice cover to being seasonally ice free has followed a pattern - from the first "BOE" it takes a decade or more to achieve a reliable annual BOE, then over time the ice-free season grows longer - melt-out arrives earlier and refreeze arrives later. This process takes time as well. And only parts of locations that are fed by a warm neighboring ocean such as the Barents (including parts of adjacent CAB) and the Bering are transitioning to a perennial ice-free state. These processes take decades. So I can't know when the CAB becomes ice-free in winter, but I can most certainly know that it will not happen when it first becomes ice-free in summer, but at least several decades after that event, most probably several centuries due to the size of the CAB and the shortness of the current melting season in the CAB compared to the freezing season.

[Rod]

you're posts are very close to be trollish IMO and sooner or later others will stumble upon and recognize it.

There is a troll in this thread, but you called out the wrong person.  The real troll is much more savvy than DanielB ever was, and he is very good at getting people to fight over nonsense.   

The real shame in this is that long time experts are not posting this year, presumably because of all the nonsense, and this year is an extremely interesting season of melting. 

The Atlantic front has moved farther north, and stayed there for longer, than at anytime ever in the satellite record.   The Beaufort gyre has clearly slowed, and possibly reversed, which might mark the first reversal since before the 2007 crash. 

These are very important issues that could mark a profound change in the ocean currents that could lead at sometime in the future to an ice free CAB. 

When, or if, that might happen is anyone's guess.   However, as A-Team remarked earlier this melt season, the time of peak solar activity does not overlap well with the time of minimum ice.   

Therefore, it is safe to say that an ice free arctic would have to be caused by more than just sunshine.   If the lower amounts of ice that we are seeing now allow warmer and more salty water to move deeper into the CAB, that could be a potential mechanism. 

This thread is based upon speculation, and that is what we are all doing.  No one knows when, or even if, the CAB will become ice free in winter.   

But it is still an interesting topic to discuss.   Just ignore the trolls, and respond to the posts that you think have merit.   

If people stop attacking each other so much, it might prompt other people who have valuable things to say to get involved in the discussion.   

[Bruce Steele]

Rod, "The Beaufort gyre has clearly slowed, and possibly reversed, which might mark the first reversal since before the 2007 crash."
 Could you give me some info on this claim? I watch the ITP Whoi data and 108 and it's path around the Beaufort seems sluggish but a reversal , a long one , would be something I haven't seen .
Would be important I agree if it were to happen.

[Rod]

Rod, "The Beaufort gyre has clearly slowed, and possibly reversed, which might mark the first reversal since before the 2007 crash."
 Could you give me some info on this claim? I watch the ITP Whoi data and 108 and it's path around the Beaufort seems sluggish but a reversal , a long one , would be something I haven't seen .
Would be important I agree if it were to happen.

I'm not claiming it has reversed.  Only that it might have.  The drift pattern of ITP108 is consistent with a reversal.   The ice it is attached to ignored the typical clockwise rotation.  It has now clearly stalled, so there is not much more we can learn from it.

Unicorn and A-Team have posted several images this melt season that show the ice flows are moving in a direction inconsistent with the typical gyre current.  I consider that to be the most compelling evidence. 

Hyperion and FishOutofWater also showed several model outputs that indicated the gyre currents had were circulating fresh water down through the CAA.  FOW commented on this most recently about a week ago. 

A close inspection of the Parry Channel over the last month (when it's not cloudy which is rare) indicates the ice is piling up in a way that would be consistent with ice being forced downward and opposite of the typical clockwise gyre pattern. 

Finally, the area in the CAB that would normally be full of ice from a typical clockwise gyre is streatched thin and looks as if it might be ice free by the end of the melt season. 

The experts have said that the gyre is due for a reversal when persistent low pressure systems settle into the Beaufort.  The Beaufort has certainly had persistent lows this summer. 

This is all circumstantial evidence.  That is why I said that at a minimum the gyre has slowed, and possibly reversed.

As I'm sure you know, we are many years past the predicted reversal.  We will just need to wait now until the experts chime in and tell us what they think has really happened.

[bbr2314]

Most recent available month or so of SLP anomalies verifying ^

[deconstruct]

e.g.
https://www.scientificamerican.com/article/oceans-can-rise-in-sudden-bursts/

Aehm.. that link references a paper that claims:
"In fact, the terraces suggest several meters of sea-level rise may have occurred on the scale of just decades during this time."

That paper claims, that sea-level rose by several meters within multiple decades. So lets say several meters are 3 meters and multiple decades are 5 decades. That would be a rise of 0.06 m per year.

Your original claim however was, that sea-level rose tens of meters in less than a decade. So lets say tens of meters are 30m and less than a decade would be 8 years, so sea level would have risen with 3.75 meters per year.

That is 60 (!) times faster than what that paper says. That is a difference of nearly 2 orders of magnitude!

That supports in no way your claim, but just shows how absurd it is, when even in the transition from the last ice age the highest speed of sea level rise is 60x lower.

[Tor Bejnar]

Deconstruct,
Did you read my post?  I like that you put numbers to DR's and the article's 'meters' and 'decades'.  You 'blew it', however, with the "nearly 2 orders of magnitude".  One order of magnitude over 3.75 is 37.5 and two orders is 375.  Where I come from, 60 is significantly closer to 37.5 than it is to 375, and, significantly, shares the same number of (greater than zero) decimal places.  (Interestingly, the absolute differences between 60 and [37.5 and 375] are over an order of magnitude different!  [22.5 and 315])
Edit: more precisely, 60 is 1.2 orders of magnitude over 3.75. [3.75 x 10^x = 60; 10^x = 16; x = log(16)]

[Dharma Rupa]

Deconstruct,
Did you read my post?  I like that you put numbers to DR's and the article's 'meters' and 'decades'.  You 'blew it', however, with the "nearly 2 orders of magnitude".  One order of magnitude over 3.75 is 37.5 and two orders is 375.  Where I come from, 60 is significantly closer to 37.5 than it is to 375, and, significantly, shares the same number of (greater than zero) decimal places.  (Interestingly, the absolute differences between 60 and [37.5 and 375] are over an order of magnitude different!  [22.5 and 315])

That's alright Tor, I just grabbed the very first article I could find on the subject.  Reality is that the guesstimates are all over the place, and I have seen papers that talked about 30 meters in less than a decade at some points in the past.  Which papers are right cannot be known, and the real point is that sudden sea level changes can happen; which tends to lend doubt about most if not all the current GCM; which do not predict the possibility of sudden change.

My real problem with some of the people who use the GCM is this:  Take two statements:

Statement 1:  Model X says Y, therefore I think Y.
Statement 2:  Model X says Y, therefore Y must be true.

Statement 1 is completely valid, and not only might help people figure out what is likely, but more importantly might help fill out the set of possibilities.

Statement 2 is pure bullshit and needs to be called out for what it is.

[gerontocrat]

e.g.
https://www.scientificamerican.com/article/oceans-can-rise-in-sudden-bursts/

Aehm.. that link references a paper that claims:
"In fact, the terraces suggest several meters of sea-level rise may have occurred on the scale of just decades during this time."

That paper claims, that sea-level rose by several meters within multiple decades. So lets say several meters are 3 meters and multiple decades are 5 decades. That would be a rise of 0.06 m per year.

Those who have worked in the South Pacific know that coral reefs are very sensitive to water depth. I found the "claim" in the paper very persuasive and logical. Yet another bit of evidence to support Hansen's abrupt SLR views. Whether that supports the argument for a winter ice free Arctic I have not a clue.

However, those living in Florida, London, New York, New Orleans, Shanghai et al, may find the findings of more immediate concern.

[Tor Bejnar]

...
However, those living in Florida, London, New York, New Orleans, Shanghai et al, may find the findings of more immediate concern.

I live at 120 feet (sounds higher than 35 m  ), so I'm tempted to say, "Bring it on."  But my pension is from the State of Florida, so I say, "Please, not here, or at least, not now."

[Tetra]

e.g.
https://www.scientificamerican.com/article/oceans-can-rise-in-sudden-bursts/

Aehm.. that link references a paper that claims:
"In fact, the terraces suggest several meters of sea-level rise may have occurred on the scale of just decades during this time."

That paper claims, that sea-level rose by several meters within multiple decades. So lets say several meters are 3 meters and multiple decades are 5 decades. That would be a rise of 0.06 m per year.

Those who have worked in the South Pacific know that coral reefs are very sensitive to water depth. I found the "claim" in the paper very persuasive and logical. Yet another bit of evidence to support Hansen's abrupt SLR views. Whether that supports the argument for a winter ice free Arctic I have not a clue.

However, those living in Florida, London, New York, New Orleans, Shanghai et al, may find the findings of more immediate concern.

As a Londoner, perhaps I should invest in a boat...or water wings.

On a more serious note, I think we’re gonna be reaping what we sow pretty soon in regards to SLR.

I also think the arctic will go ice free within the decade, thanks to atlantification, rate of volume and extent loss since 1979 finally catching up to the present, and etc, as well as my own gut acting up and informing me I’m right.

As that quote from Deus Ex Human revolution goes- “It’s not quite the end of the world ice, but you can see it from here”.

[deconstruct]

You 'blew it', however, with the "nearly 2 orders of magnitude". 
One order of magnitude[/url] over 3.75 is 37.5 and two orders is 375.  Where I come from, 60 is significantly closer to 37.5 than it is to 375, and, significantly, shares the same number of (greater than zero) decimal places.

I would recommend, that you read my post again.

The cited paper speaks from a sea-level rise 0.06 m per year.
Dharma Rupas claim was a rise of 3.75 m per year.

In other words: DRs rate is 60 times the rate of the one from the paper.

One order of magnitude would be 10 times the rate.
Two orders of magnitude would be 100 times the rate.

60 times is IMHO "nearly 2 orders of magnitude", and in any case is 60 nearer to 100 than to 10, if you want it spelled out in your logic.

I have no idea where you get the idea to compare 3.75 meters per year with 60 meters per year (which nobody ever spoke of).

[Tor Bejnar]

Yup, I missed something:  I saw your numbers, and when I fetched them (after starting to write my post) to 'do the math', I got the 60 from 60x instead of the 0.06 rate.  (I grabbed the wrong "6".)  Sorry about that.  (It works out that 3.75 is 1.8 orders of magnitude over 0.06.)

[deconstruct]

That's alright Tor, I just grabbed the very first article I could find on the subject.

Oh my god...
That paper contradicts your claim!

If you make an extraordinary claim that IMO is nowhere in the ballpark of reality, it is obviously not enough to "grab the first article on the subject". You should grab an article that supports your claim. I can't even wrap my brain around your logic..

Reality is that the guesstimates are all over the place, and I have seen papers that talked about 30 meters in less than a decade at some points in the past.

Again: Show that paper please.

A rise of 30 meters in less than a decade is complete and utter nonsense.

Just a back-of-the-envelope calculation:

• The energy required to melt enough ice for a 30m sea-level-rise (about 10¹⁶ cubic meters of water)
  1.08 * 10¹⁹ kg * 3.335 * 10⁵ J/kg
  = 10²¹ Wh
• The energy absorbed by the whole earth surface for a radiative forcing of 1 Watt/m² over 7 years is
  5.1 * 10¹⁴ m² * 1 W/m² * 7 * 8760 h 
  = 3.13 * 10^19 Wh

So, to melt that much ice in 7 years, you would need the energy from a radiative imbalance of 32 W/m² that goes completely into melting ice. Just to compare: The radiative forcing from a doubling of CO2 is only 3.7 W/m². The whole radiation from the sun absorbed by the earth surface is only about 170 W/m², so we talk about nearly 20% of the total energy received from the sun!

And that heat would have to go completely into ice melting, so no warming of the oceans etc.

Such an amount of energy delivered in such a small period of time is totally unrealistic and could only delivered e.g. by an dinsoaur-grade asteroiod impact, which didn't happen in that time.

[oren]

Deconstruct, while I disagreed with the original comment mentioning tens of meters SLR in a decade as a way to discredit climate models, I think you might be going too far in decnstructing that comment.
During the final draining of Lake Agassiz, sea level (away from north America) is estimated to have risen several meters in less than one year, which is the same rate as touted in the original comment (but does not support it or its assertions). You might wonder how that happened, given your melt rate calculations? Quite simple really. Meltwater that have accumulated on land over centuries from the melting and retreat of a continental ice sheet suddenly burst their ice dam (following changes in continental topography), and flowed to the sea. This cannot happen today as there are no appropriate ice sheets to feed such a phenomenon.
(Antarctica due to its location and climate is retreating at its oceanic edges, while Greenland is too small and too close to the sea to manage to accumulate large amounts of meltwater held back by ice).

https://en.m.wikipedia.org/wiki/8.2_kiloyear_event
For the SLR discussion read the "Cooling Event" section.

[Sterks]

BBR, saw your maps of temperatures in Iberia and NW Africa for June and July. Well, the temperatures there vary quite a lot from month to month as can be seen here.

Haven't you heard about the difference between climate and weather?

Of all things said on this funny thread, I support the evidence (as measured by the cells of my skin, my June-July electricity bill, and family of mine probing different areas of the Iberian peninsula by the same methods) that this summer in Spain has been mild, even pleasant, with the exception of the first week of August. It is OK now!

The rest is speculation.

Carry on

[Shared Humanity]

you're posts are very close to be trollish IMO and sooner or later others will stumble upon and recognize it.

There is a troll in this thread, but you called out the wrong person.  The real troll is much more savvy than DanielB ever was, and he is very good at getting people to fight over nonsense.   

The real shame in this is that long time experts are not posting this year, presumably because of all the nonsense, and this year is an extremely interesting season of melting. 

The Atlantic front has moved farther north, and stayed there for longer, than at anytime ever in the satellite record.   The Beaufort gyre has clearly slowed, and possibly reversed, which might mark the first reversal since before the 2007 crash. 

These are very important issues that could mark a profound change in the ocean currents that could lead at sometime in the future to an ice free CAB. 

When, or if, that might happen is anyone's guess.   However, as A-Team remarked earlier this melt season, the time of peak solar activity does not overlap well with the time of minimum ice.   

Therefore, it is safe to say that an ice free arctic would have to be caused by more than just sunshine.   If the lower amounts of ice that we are seeing now allow warmer and more salty water to move deeper into the CAB, that could be a potential mechanism. 

This thread is based upon speculation, and that is what we are all doing.  No one knows when, or even if, the CAB will become ice free in winter.   

But it is still an interesting topic to discuss.   Just ignore the trolls, and respond to the posts that you think have merit.   

If people stop attacking each other so much, it might prompt other people who have valuable things to say to get involved in the discussion.

Quoted in its entirety because I do this when I encounter a perceptive post.

Trolls have tells and, while I am generally opposed to banning on any forum, Neven should exercise this when it becomes obvious.

I also miss very much some of the experts who come around far less often, whatever their reason.

[Shared Humanity]

Deconstruct,
Did you read my post?  I like that you put numbers to DR's and the article's 'meters' and 'decades'.  You 'blew it', however, with the "nearly 2 orders of magnitude".  One order of magnitude over 3.75 is 37.5 and two orders is 375.  Where I come from, 60 is significantly closer to 37.5 than it is to 375, and, significantly, shares the same number of (greater than zero) decimal places.  (Interestingly, the absolute differences between 60 and [37.5 and 375] are over an order of magnitude different!  [22.5 and 315])

That's alright Tor, I just grabbed the very first article I could find on the subject.  Reality is that the guesstimates are all over the place, and I have seen papers that talked about 30 meters in less than a decade at some points in the past.  Which papers are right cannot be known, and the real point is that sudden sea level changes can happen; which tends to lend doubt about most if not all the current GCM; which do not predict the possibility of sudden change.

My real problem with some of the people who use the GCM is this:  Take two statements:

Statement 1:  Model X says Y, therefore I think Y.
Statement 2:  Model X says Y, therefore Y must be true.

Statement 1 is completely valid, and not only might help people figure out what is likely, but more importantly might help fill out the set of possibilities.

Statement 2 is pure bullshit and needs to be called out for what it is.

This is very tiresome.

[Shared Humanity]

As a Londoner, perhaps I should invest in a boat...or water wings.

With very rapid sea level rise, a boat is advisable.

I'm getting a bulldozer to deal with the more immediate threat of deepening BS on this thread.

[binntho]

Speculation is fun, and this thread is of course pure speculation. But when somebody makes repeated claims that they are unable to substantiate, but still feel they can use them as arguments in discussions, even going to the lengths of condescending the opinions on others, then they should expect to be called out.

A bit more of "I think this might be the case" and somewhat less of "I make this claim and become very angry and hurt if I'm forced to back it up" and the experts might come back?