When will the Arctic Go Ice Free?

[Shared Humanity]

I had another look at my 365 Day trailing Averages, i.e. the continuous trend in average annual sea ice over the years.

I don't see how anyone can say that sea ice is not declining. And this concentration on the minimum - one day in the 365 day year, seems designed to ensure lack of light.

ps: When the area & volume lines cross, average thickness for the whole year will be less than 1 metre.

Sea ice is still declining but using the 365 Day trailing average hides the fact that volume at maximum is falling faster than volume at minimum. The decline in volume at minimum has stalled over the past decade and the behavior of SIE, SIA and Volume at minimum is what will determine when we have a BOE.

[binntho]

I had another look at my 365 Day trailing Averages, i.e. the continuous trend in average annual sea ice over the years.

I don't see how anyone can say that sea ice is not declining. And this concentration on the minimum - one day in the 365 day year, seems designed to ensure lack of light.

ps: When the area & volume lines cross, average thickness for the whole year will be less than 1 metre.

Somewhere around 2040? I can't really see a realistic scenario where the average thickness is 1 metre for a whole year, something will have to  give before then.

[Sam]

Did you even look at the chart? Here is another.

Yes. Of course. All I see is statistical noise, quite similar to the fake talking point of a pause a few years back.

Sam

[binntho]

Did you even look at the chart? Here is another.

Yes. Of course. All I see is statistical noise, quite similar to the fake talking point of a pause a few years back.

Sam

I'm getting that Groundhog Day feeling ...

[Klondike Kat]

Did you even look at the chart? Here is another.

Yes. Of course. All I see is statistical noise, quite similar to the fake talking point of a pause a few years back.

Sam

I'm getting that Groundhog Day feeling ...

Yes, some will only see what they want to see.

[blumenkraft]

Yes, some will only see what they want to see.

I wonder if this is a projection. 

[Shared Humanity]

Attached is a chart that includes 2018 volume which the previous chart did not have. We see the massive reduction in volume at minimum that occurred in 2007 and 2010. In the following 8 years, volume at minimum has been remarkably stable, bouncing around the volume at minimum we see in 2010. Are 8 years sufficient to demonstrate a change in behavior? Perhaps not. Does the PIOMAS model accurately assess volume at minimum? I believe some have said that PIOMAS overestimates thickness when the ice is thin so perhaps not. Never the less, I see a flattening of the volume losses over the last 8 years.

Can't wait for September PIOMAS numbers.

[Shared Humanity]

I got hooked on this site after the 2012 melt season. (Registered here on February 27, 2013) Like many here, I thought we were only a year or 2 away from a BOE and I wanted to follow this while being informed by the experts who post here. We are heading towards a climate catastrophe. BAU will continue for the next couple of decades and it will be the death of us (quite literally).

I no longer think a BOE is going to occur soon (in the next decade) but this will have very little if any impact on our future.

[binntho]

We see the massive reduction in volume at minimum that occurred in 2007 and 2010. In the following 8 years, volume at minimum has been remarkably stable ...

Remarkably stable? I'm seeing the curve going remarkably unstable.

[binntho]

I see a flattening of the volume losses over the last 8 years.

So I guess you see an even more marked flattening of volume in these 9 years?
(1993-2001)

[Shared Humanity]

I see a flattening of the volume losses over the last 8 years.

So I guess you see an even more marked flattening of volume in these 9 years?
(1993-2001)

I have posted 6 charts with my non expert commentary to explain why I think a BOE is at least a decade away and you post that?

Nice......

[crandles]

I see a flattening of the volume losses over the last 8 years.

So I guess you see an even more marked flattening of volume in these 9 years?
(1993-2001)

And I wonder where the gompertz fit is going in those years. 

[Shared Humanity]

As long as we are posting misleading stuff...

[blumenkraft]

#justsaying

[vox_mundi]

Lesson Learned: Don't eat cheese and go to bed in tangled sheets. 

[Shared Humanity]

One takeaway from the ice age chart is that, while 3 YO, 4 YO and 5 YO ice have suffered steep declines, 2 YO ice has remained remarkably stable. This is because some 1 YO ice survives each year north of 80 degrees.

Will ice older than 2 years continue to suffer declines? The pack is much more fragmented and highly mobile with Fram export, the garlic press and dispersion into peripheral seas more likely now than ever before so I think the answer is yes. Will some FYI continue to survive north of 80 degrees? I think the answer to this is yes as well. I also think that when the first BOE occurs and it will, it is very likely that some 1st year ice will survive in the subsequent melt season so that a perennially ice free fall is not going to be the result of that 1st BOE.

[Klondike Kat]

I see a flattening of the volume losses over the last 8 years.

So I guess you see an even more marked flattening of volume in these 9 years?
(1993-2001)

No, that is the opposite.  When it went from relatively flat in the previous decade to a steep decline in the subsequent decade.

[binntho]

I see a flattening of the volume losses over the last 8 years.

So I guess you see an even more marked flattening of volume in these 9 years?
(1993-2001)

I have posted 6 charts with my non expert commentary to explain why I think a BOE is at least a decade away and you post that?

Nice......

Well, when you make statements like "remarkably stable" and "flatlining" about 8 highly variable datapoints in a graph that is clearly only fit for at the very best a linear trendline, then you can't expect me focus on your other points.

As for BOE, I see nothing in the charts that you've posted that supports any statements about whether a BOE is imminent or not. These charts do not allow themselves to be used in that way.

[binntho]

I see a flattening of the volume losses over the last 8 years.

So I guess you see an even more marked flattening of volume in these 9 years?
(1993-2001)

No, that is the opposite.  When it went from relatively flat in the previous decade to a steep decline in the subsequent decade.

No it didn't! If you call a higly variable 8 year run "remarkably stable" and "flatlinining" then anything and everything becomes possible, so if I say that it went from relatively steep decline to a relatively flatline in the subsequent few years followed by marked drops and a few intrepid rises, puncutated by a few years that didn't really do anything, then I am talking just as much rubbish!

Please, can we try to limit ourselves to statements that can be supported by data?

[Tom_Mazanec]

Arctic ice declining faster than predicted by most climate models
http://www.digitaljournal.com/news/environment/arctic-ice-declining-faster-than-predicted-by-most-climate-models/article/557088

From the new findings, climate projections now suggest that Arctic summer sea-ice could disappear within the course of the next fifty or even thirty years, unless urgent action is taken. The findings show the situation to be worse that many other models of the impact of global warming upon the Arctic; this is because the new research finds a faster rate of global warming in the Arctic region, ahead of global averages. One reason for this may be due to increasing air temperatures and precipitation, which are drivers of major changes in various components of the Arctic system.
The researchers are basing this on a 200-year assessment of past sea-ice variability from High Arctic Svalbard (located at 79.9°N). Svalbard is a Norwegian archipelago in the Arctic Ocean. Svalbard is a breeding ground for many seabirds, and also features polar bears, reindeer, and the Arctic fox.

[Klondike Kat]

I see a flattening of the volume losses over the last 8 years.

So I guess you see an even more marked flattening of volume in these 9 years?
(1993-2001)

I have posted 6 charts with my non expert commentary to explain why I think a BOE is at least a decade away and you post that?

Nice......

Well, when you make statements like "remarkably stable" and "flatlining" about 8 highly variable datapoints in a graph that is clearly only fit for at the very best a linear trendline, then you can't expect me focus on your other points.

As for BOE, I see nothing in the charts that you've posted that supports any statements about whether a BOE is imminent or not. These charts do not allow themselves to be used in that way.

Funny how after all the data and evidence to the opposite, you cling to the claim that a linear trendline is the very best.  I guess my earlier post in more valid than I originally thought.

[Shared Humanity]

binntho...

I have yet to call anything you say as rubbish or cast aspersions on your efforts to argue a viewpoint different than my own. I still feel the way I do about whether a BOE is likely in the next decade and my future posts will likely try to make this case, essentially trying to answer the question that is the title of this thread.

You can respond as you see fit but I guess I would prefer your responses make a compelling argument that helps me understand my mistakes as opposed to simply calling what I post rubbish.

But then, that is just me.

[Klondike Kat]

Arctic ice declining faster than predicted by most climate models
http://www.digitaljournal.com/news/environment/arctic-ice-declining-faster-than-predicted-by-most-climate-models/article/557088

From the new findings, climate projections now suggest that Arctic summer sea-ice could disappear within the course of the next fifty or even thirty years, unless urgent action is taken. The findings show the situation to be worse that many other models of the impact of global warming upon the Arctic; this is because the new research finds a faster rate of global warming in the Arctic region, ahead of global averages. One reason for this may be due to increasing air temperatures and precipitation, which are drivers of major changes in various components of the Arctic system.
The researchers are basing this on a 200-year assessment of past sea-ice variability from High Arctic Svalbard (located at 79.9°N). Svalbard is a Norwegian archipelago in the Arctic Ocean. Svalbard is a breeding ground for many seabirds, and also features polar bears, reindeer, and the Arctic fox.

50 years is faster than most climate models?

From the article.

"The new algal proxy record provides the first marine annual-resolution long-term seaice data from the High Arctic suggesting that sea-ice decline at Svalbard had already started in the early 20th century. The onset of the ongoing sea-ice decline at the end of the Little Ice Age has previously been related to atmospheric warming driven by enhanced atmospheric and ocean heat transport from the North Atlantic to the Arctic, and is believed to be at least partly explained by natural climate-system variability (Bengtsson et al., 2004).

Our data indicate that the lowest sea-ice values during the past 200 yr are from the 1980s to the
early 2000s. In addition, the new algal proxy now provides a means to resolve underlying decadalto multidecadal-scale variability, showing prominent variability at 38–50 and 90 yr, which is not possible with short remotely sensed time series, and for the first time allows tracking of northern Svalbard sea-ice variability back to the start of the 19th century. Although our proxy record provides evidence for brief periods of higher sea-ice cover during the past two centuries as part of low-frequency variations, the long-term declining trend in sea ice around Svalbard started earlier than was previously reported, and is expected to continue with rapid future Arctic warming."

[binntho]

Funny how after all the data and evidence to the opposite, you cling to the claim that a linear trendline is the very best.  I guess my earlier post in more valid than I originally thought.

What data and evidence to the opposite? I haven't seen any. In fact, I had the impression that I had shown conclusively that the linear trend is the only trend we can see in these 40 data-point graphs.

Statistically there is no support whatsoever for changes in trend when looking at these graphs, and physically there is only support for a linear decline.

[binntho]

binntho...

I have yet to call anything you say as rubbish or cast aspersions on your efforts to argue a viewpoint different than my own. I still feel the way I do about whether a BOE is likely in the next decade and my future posts will likely try to make this case, essentially trying to answer the question that is the title of this thread.

You can respond as you see fit but I guess I would prefer your responses make a compelling argument that helps me understand my mistakes as opposed to simply calling what I post rubbish.

But then, that is just me.

Rubbish is strong language, sorry about that - feeling a bit grumpy yesterday. Perhaps because I've just been having a long discussion with Klondike Kat, pointing out how it is impossible to make any claims about the various annual datasets other than that they show a linear decline.

And then you come along and make the same erroneous claims as Klondike Kat made, hence my "Groundhog Day" comment a bit further up.

You claim that the red graph in your reply 1006 shows that the last 8 years had been "remarkably stable" and implying that it has flatlined. Precisely you said:

We see the massive reduction in volume at minimum that occurred in 2007 and 2010. In the following 8 years, volume at minimum has been remarkably stable, bouncing around the volume at minimum we see in 2010.

I've copied the graph and marked your "remarkably stable" period (lower right corner), and another "remarkably stable" period that I think is even more "remarkably stable" and covering a lot more years (upper left).

Both are totally wrong. There are no "remarkably stable" periods, and there are no changes in trendline that can be shown statistically. The two framed periods both show "flatlining" if that is what we want them to show, in both cases volume fluctuates around an earlier low value.

As for your thoughts on when BOE might occur, I guess they are just as valid as any other since we don't really have anything in our data to support one hypothesis over another.

We have a series of datasets where straight trendlines are the only options, both statistically and in view of the fact that the only quantifiable driver of these changes, and by far the strongest one, i.e. our relentlessly warming world, is also best represented by a linear trendline over the same period.

And when we project these linear trendlines into the future they don't match up, they reach nullpoints decades apart, which tells us that these datasets are not likely to continue to show linear trends.

So what will happen? Your guess is as good as mine, but the data doesn't support either.

[KiwiGriff]

One point worth considering.
Using only mark one eyeball I would bet a curve would be a much better fit than a straight line to either data set. 
Acceleration not a steady decline.
Someone from ASIF did ask tamino to look into this on his  blog post before last .
Warming also shows acceleration.
 

[binntho]

One point worth considering.
Using only mark one eyeball I would bet a curve would be a much better fit than a straight line to either data set. 
Acceleration not a steady decline.
Someone from ASIF did ask tamino to look into this on his  blog post before last .
Warming also shows acceleration.

I'd love to see Tamino correct us all! But I don't think we have enough to go on yet to claim acceleration. In a few years perhaps, and it certainly wouldn't surprise me.

[blumenkraft]

In a few years perhaps, and it certainly wouldn't surprise me.

Well, if it wouldn't surprise you, you think it's a likely outcome, right?

Why are you questioning the premise then? This is highly illogical.

[binntho]

In a few years perhaps, and it certainly wouldn't surprise me.

Well, if it wouldn't surprise you, you think it's a likely outcome, right?

Why are you questioning the premise then? This is highly illogical.

What premise am I questioning? I don't recall questioning other than dubious claims about charts and graphs. These dubious claims may well have been made on the basis of a very valid premise, e.g. that the ice is diminishing in a non-linear fashion. But again, the claims that the graphs support anything other than linear decline with high variance are highly questionable.

[crandles]

Using only mark one eyeball I would bet a curve would be a much better fit than a straight line to either data set. 
Acceleration not a steady decline.
Someone from ASIF did ask tamino to look into this on his  blog post before last .
Warming also shows acceleration.

Acceleration Huh?
We have just been discussing

https://tamino.wordpress.com/2016/07/17/arctic-heat/

Acceleration and more recently deceleration appears to have been shown to be statistically significant.

[binntho]

Acceleration and more recently deceleration appears to have been shown to be statistically significant.

Indeed it is, based on the full daily dataset that Tamino uses. The number of datapoints here are well sufficient to make such claims.

The problem is that we have no explanation for neither the acceleration nor the deceleration, which leaves open the possibility that it didn't happen!

[crandles]

What proportion of the models, where we can see enough of approach towards 0 ice, show acceleration then deceleration?

[binntho]

What proportion of the models show acceleration then deceleration?

They all do as far as I can see, and that is perfectly reasonable to my mind. But none of the modelled ac/deceleration explains the trend changes in Tamino's graph. We are unable to explain why sea ice melt should have accelerated around 2002 and decelerated around 2007/8. That's in the past so we should be able to come up with something!

And since we can't, how on earth do you expect anybody to come up with any viable hypothesis claiming that we are in a melt hiatus now, when the statistics don't support it and our knowledge of the underlying forces is so patchy that we can't even explain what happened 10 years ago!

[MyACIsDying]

Using only mark one eyeball I would bet a curve would be a much better fit than a straight line to either data set. 
Acceleration not a steady decline.
Someone from ASIF did ask tamino to look into this on his  blog post before last .
Warming also shows acceleration.

Acceleration Huh?
We have just been discussing

https://tamino.wordpress.com/2016/07/17/arctic-heat/

Acceleration and more recently deceleration appears to have been shown to be statistically significant.

KiwiGriff writes: Warming is accelerating, not ice loss is accelerating. Would you disagree global temps, OHC & SST are accelerating in increase?

[oren]

Acceleration and deceleration are easily explained by a major loss of MYI which indeed happened.
However, what is missing from the (very long) discussion is the increased volatility around the trend. Even if the trend slows down, I'll be very surprised if the first BOE (1M km2) does not happen by 2030.

[KiwiGriff]

how on earth do you expect anybody to come up with any viable hypothesis claiming that we are in a melt hiatus now

This particular graph shows just about all we can be confident in. The data are noisy enough that those are the only changes we can assert with genuine statistical justification. Yes there was a speedup of ice loss from about 2002 through 2006, after which the rate of decline is indistinguishable from its previous rate.

https://tamino.wordpress.com/2016/07/17/arctic-heat/
I would love tamino to revisit this with  three more years of data .
Talk of a haitus reminds me of the "pause" in warming
Unless there is a well supported physical reason why ice has stopped melting.

Ocean heat content in the arctic is  increasing. 
https://advances.sciencemag.org/content/4/8/eaat6773.full
 
As are surface temperatures.
https://arctic.noaa.gov/Report-Card/Report-Card-2018/ArtMID/7878/ArticleID/783/Surface-Air-Temperature

 

[crandles]

KiwiGriff writes: Warming is accelerating, not ice loss is accelerating. Would you disagree global temps, OHC & SST are accelerating in increase?

KiwiGriff wrote 'either dataset' and it is possible I misunderstood at least one of the datasets to be Arctic sea ice.

I accept an acceleration for recent compared with around 1940-1970 for global temps, OHC & SST. For arctic temps maybe some acceleration for 2000-2019 compared to 1980 to 2000. But is the cause or consequence of ice retreat? Maybe a bit of both but seems more consequence to me as it is mainly concentrated in autumn being the ocean giving up extra heat it has accumulated as a result of albedo feedback i.e. because the ice has retreated.

[crandles]

But none of the modelled ac/deceleration explains the trend changes in Tamino's graph. We are unable to explain why sea ice melt should have accelerated around 2002 and decelerated around 2007/8. That's in the past so we should be able to come up with something!

And since we can't, how on earth do you expect anybody to come up with any viable hypothesis claiming that we are in a melt hiatus now, when the statistics don't support it and our knowledge of the underlying forces is so patchy that we can't even explain what happened 10 years ago!

Tamino piecewise fit finds 4 year with rate of decline about 7.5 times faster than rate after the steep section.

I certainly can't rule it out, but does this feel a bit extreme. I don't think we should rule out this being a bit overfitted.

What Tamino has done to see if it is statistically significant is fine. For other purposes different analysis might be preferable. Consequently, with that 7.5 time faster rate for 4 years feeling extreme, I would prefer to fit a curve through the data.

The gompertz curve I use is not ideal for some purposes; I don't believe the completely flat extrapolation. But lacking anything better, the gompertz fit has point of inflection in 2005 and the fast rate of decline from circa 2000-2010. This date range fits better with the MYI rapid decline.

Feels like it hangs together pretty well to me. It is of course possible that I am trying too hard to make the pieces fit and seeing things fitting together when they don't.

[KiwiGriff]

Yes I said it appeared ice melt is accelerating going by the graph posted above.

hpwever.
If tamino says that it did  speed up for a short period then reverted back to the trend I will except that until someone with as much authority in statistics can show me other wise.
I reserve the right  to suggest to tamino san that four years seems a very short period to discern a trend with something so effected by the variability of weather.

[DavidR]

Using only mark one eyeball I would bet a curve would be a much better fit than a straight line to either data set. 
Acceleration not a steady decline.
Someone from ASIF did ask tamino to look into this on his  blog post before last .
Warming also shows acceleration.

Acceleration Huh?
We have just been discussing

https://tamino.wordpress.com/2016/07/17/arctic-heat/

Acceleration and more recently deceleration appears to have been shown to be statistically significant.

We have to  remember that any graph is a two dimensional representation of a multi-dimensional issue. Any trend line or formula is a further reduction.  The change analysis is interesting but without identifying  a causal relationship is not telling us much.  The years 2005-2007were remarkably  warm in  the Arctic but  since then similar temperatures are not 'remarkable'.

There is a good reason why climate specialists look at  30 years of data, and anything  less than that  is just  noise. Fun to  discuss but  just  noise.   

[Klondike Kat]

In the last few days, we have had several analyses of the trend of minimum Arctic sea ice.   Extrapolating these trends yields forward, the following estimates for the first onset of an ice-free Arctic (< 1M km2) are derived:

Glen Koehler:  2030, based on Wipneus graph of volume minimum
gerontocrat:  2040, based on PIOMASS area and volume trends crossing (<1m ice ave. thickness)
binntho:  2059, simple linear trend of NSIDC minimum extent since 1979
Tom_Mazance:  2069, from Hetzinger, et. al. (20 years earlier, if rapid Arctic melting)
aslan:  2080, from Xia, et. al. derived from latitudinal retreat of sea ice edge.
Shared Humanity:  2111, based on the decline in MYI over the past decade
crandles:  2139, from Tamino "continuous piecewise linear trend"
crandles:  >2100, from Eisenman ensemble of climate models (also from 4-parameter gompertz)

Interestingly enough, 70% of posters voting on this thread chose a date for an ice-free Arctic extent earlier than even the soonest value derived, and 90% earlier than all but the Wipneus trend for minimum volume.  What do the posters know that the experts do not?

[binntho]

Acceleration and deceleration are easily explained by a major loss of MYI which indeed happened.
However, what is missing from the (very long) discussion is the increased volatility around the trend. Even if the trend slows down, I'll be very surprised if the first BOE (1M km2) does not happen by 2030.

No I don't think that explanation holds water for an acceleration 2002-2007. There was no major change in MYI in that period, it just kept diminishing. The big changes come after 2007 and particularly 2012.

So loss of multi year ice could possibly be used to explain decelaration after 2007 (although 2012 would have been a much better fit) but not acceleration in 2002.

[binntho]

Interestingly enough, 70% of posters voting on this thread chose a date for an ice-free Arctic extent earlier than even the soonest value derived, and 90% earlier than all but the Wipneus trend for minimum volume.  What do the posters know that the experts do not?

Including me! But I don't know nothing.

[crandles]

In the last few days, we have had several analyses of the trend of minimum Arctic sea ice.   Extrapolating these trends yields forward, the following estimates for the first onset of an ice-free Arctic (< 1M km2) are derived:

...
crandles:  2139, from Tamino "continuous piecewise linear trend"
crandles:  >2100, from Eisenman ensemble of climate models (also from 4-parameter gompertz)

Interestingly enough, 70% of posters voting on this thread chose a date for an ice-free Arctic extent earlier than even the soonest value derived, and 90% earlier than all but the Wipneus trend for minimum volume.  What do the posters know that the experts do not?

I try to be clear that I do not believe the completely flat extrapolation of 4 parameter gompertz fit.

I actually voted 2026-2030 but perhaps 2030-2060 more accurately reflects what I think reasonably likely.

[Klondike Kat]

In the last few days, we have had several analyses of the trend of minimum Arctic sea ice.   Extrapolating these trends yields forward, the following estimates for the first onset of an ice-free Arctic (< 1M km2) are derived:

...
crandles:  2139, from Tamino "continuous piecewise linear trend"
crandles:  >2100, from Eisenman ensemble of climate models (also from 4-parameter gompertz)

Interestingly enough, 70% of posters voting on this thread chose a date for an ice-free Arctic extent earlier than even the soonest value derived, and 90% earlier than all but the Wipneus trend for minimum volume.  What do the posters know that the experts do not?

I try to be clear that I do not believe the completely flat extrapolation of 4 parameter gompertz fit.

Yes, you have made that clear.  I do not either, but it is an alternative (as unlikely as it may be).

[Shared Humanity]

Unless there is a well supported physical reason why ice has stopped melting.

The ice at minimum now is mostly north of 80 degrees and still nested along the CAA. This ice will be more difficult to melt out and thus will continue to result in 2nd year ice forming.

[Shared Humanity]

Shared Humanity:  2111, based on the decline in MYI over the past decade

Could you point out where I said 2111 when I actually said not before 2030? Everyone here has been trying to use charts to determine when we will see our first BOE. I have been providing reasons why I believe the declines in SIE at minimum has slowed. I really don’t give a flying fuck what extrapolating a chart says.

[oren]

In the last few days, we have had several analyses of the trend of minimum Arctic sea ice.   Extrapolating these trends yields forward, the following estimates for the first onset of an ice-free Arctic (< 1M km2) are derived:

Extrapolating these trends does not give an estimate for the first onset. For that you need to include the volatility or variability around the trend.

[Shared Humanity]

One last attempt at answering the question posed by this thread...

We had perfect conditions for extraordinary melt seasons in 2007, 2010 and 2012. This resulted in new records set for minimum volume in each of these years. (See 1st chart.)

These record melt seasons also decimated MYI with 5 year old ice totals collapsing to a fraction of what they had historically been. (See 2nd chart.)

With far more 1st year ice now in the Arctic, we see a dramatic jump in variability in SIE minimums as FYI is far more sensitive to the particular characteristics of individual melt seasons. (See 3rd chart.)

Since 2012, the sea ice that survives the melt season can be found hiding out north of 80 degrees and along the CAA. This is no different than prior to these extraordinary melt seasons and this behavior has always been the predominant reason for the Arctic creating thick MYI. The difference is that the MYI created now is mainly 2nd year ice. (See 1st chart.)

The last refuge of Arctic ice north of 80 degrees and nested along the CAA will prove to be more difficult to melt IMHO and the flattening of the graph over the last decade of SIE at minimum (See chart 5.) and volume minimums (See chart 1.) captures this. So, what will it take to have our 1st BOE? I am not entirely certain but I will put out some suggestions and I believe all of these will need to happen.

1. Historically high export of ice through the Fram during the winter.
2. A very active garlic press, resulting in much of the remaining MYI exiting the CAB.
3. Continued increases in dispersion with much of the ice that survives a melt season finding its way into peripheral seas and setting the stage for melting the following year. Conversely, compaction into the refuge at the end of a melt season will always result in the creation of more resilient MYI.
4. Export into the Barents throughout the winter, ensuring its demise in the next melt season.
5. A record warm freeze season, retarding the formation of ice. Similar to or worse than 2016. (See 4th chart.)
5. A perfect melt season.

There are likely more.

[binntho]

SharedHumanity, I salute your efforts!

And I mostly agree with you, except (as could be expected)  for where you say "... and the flattening of the graph of SIE at minimum over the past decade ...". I don't think that there is a flattening, but a steady (if highly variable) decline.

And this presumption actually changes everything. If we presume that the ice is flatlining around 4M then what you are saying is quite reasonable.

But if we assume a steady decline, as per the trendline in this image of -0.811 MKm2 per decade then we should be seeing values hovering betwen 3 and 4 in the 20's and 2 and 3 in the 40's.



But these values to me indicate an increasingly unstable ice pack. If we had half the extent we have now, I think it would more or less automatically be blown all over the place and melt out more or less constantly.

So my attempt at an answer: In the 20's a combination of extremes may give us our first BOE. In the 30's a BOE will start to happen regularly, in the 40's it will be more or less an annual event.