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When will the Arctic Extent dip below 1,000,000 Km^2

2018-2019
12 (17.9%)
2020-2025
21 (31.3%)
2026-2030
13 (19.4%)
2031-2040
15 (22.4%)
2041-2060
2 (3%)
2061-2080
0 (0%)
2081-2099
1 (1.5%)
2100-beyond
3 (4.5%)

Total Members Voted: 64

Voting closed: July 27, 2018, 07:46:32 AM

Author Topic: When will the Arctic Go Ice Free?  (Read 132719 times)

TeaPotty

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Re: When will the Arctic Go Ice Free?
« Reply #700 on: July 23, 2019, 08:19:58 PM »
The smugness and passive-agreesive bullying in this thread shows exactly why the public thinks so lowly of academics. You truly are some of the saddest and most insular bootlickers in modern society. Past scientists would look down on you in shame.

You are not better than us.
You are not smarter than us.
Many of you are emotionaly immature, lacking human relationships.
Many of you are overly-pampered brats who truly believe you are superior.

Bullying non-academics by arguing semantics and using nonsensical IPCC estimates won’t change what actual math and Science shows us. Neither will it change how we will remember your “tribe” as one of the leading advocates driving our climate crisis, who accept whatever the 1% do, as long as it’s done politely.

You truly disgust me and other normal non-academics I know.

There are more useful responses to the information that Ken has posted.

Of course, but it’s not worth the time, not any longer.

It takes a lot less energy to post bullshit than it takes to refute it. I’m not wasting my time arguing with bootlickers anymore. Their only salvation is expiry, bc they will never admit they were ever wrong about not fighting to save the Climate for their descendants.

Again, they take greater care and precaution with money than human life. Even with 10 years remaining at best to try stopping a collapse of civilization, the only risk they see is to Capitalism and their own perceived superiority.

Shared Humanity

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Re: When will the Arctic Go Ice Free?
« Reply #701 on: July 23, 2019, 09:04:28 PM »
The smugness and passive-agreesive bullying in this thread shows exactly why the public thinks so lowly of academics. You truly are some of the saddest and most insular bootlickers in modern society. Past scientists would look down on you in shame.

You are not better than us.
You are not smarter than us.
Many of you are emotionaly immature, lacking human relationships.
Many of you are overly-pampered brats who truly believe you are superior.

Bullying non-academics by arguing semantics and using nonsensical IPCC estimates won’t change what actual math and Science shows us. Neither will it change how we will remember your “tribe” as one of the leading advocates driving our climate crisis, who accept whatever the 1% do, as long as it’s done politely.

You truly disgust me and other normal non-academics I know.

There are more useful responses to the information that Ken has posted.

Of course, but it’s not worth the time, not any longer.


I have to disagree.

Ken presents in a calm, reasoned manner, backed up by a thorough analysis by the best scientists on the planet, that we will be OK. This IPCC report makes it clear that a 1.5 C, even a 2.0 C, increase in global temperatures, while painful, will not be catastrophic. He omits entirely (And I believe he knows this.) that we are hurtling past 2 C warming. I have always been impressed with Ken's knowledge on the science. His read on what the IPCC says is spot on, no doubt due to his thorough reading of this document. It is curious then that he chooses to skip over the statements made in this document regarding the absolute need to eliminate all human global warming emissions by 2050 in order to prevent warming in excess of 2.0 C.

TeaPotty

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Re: When will the Arctic Go Ice Free?
« Reply #702 on: July 23, 2019, 09:28:25 PM »
There are more useful responses to the information that Ken has posted.

Of course, but it’s not worth the time, not any longer.


I have to disagree.

Ken presents in a calm, reasoned manner, backed up by a thorough analysis by the best scientists on the planet, that we will be OK. This IPCC report makes it clear that a 1.5 C, even a 2.0 C, increase in global temperatures, while painful, will not be catastrophic. He omits entirely (And I believe he knows this.) that we are hurtling past 2 C warming. I have always been impressed with Ken's knowledge on the science. His read on what the IPCC says is spot on, no doubt due to his thorough reading of this document. It is curious then that he chooses to skip over the statements made in this document regarding the absolute need to eliminate all human global warming emissions by 2050 in order to prevent warming in excess of 2.0 C.

I don’t care how calm or polite sociopaths are.
I’ve been studying, arguing, and fighting for Climate Action nearly 20 years now. I have yet to encounter any online or IRL discussion resulting in someone changing their mind and admitting they’re wrong about Climate consequences.

Indeed, most make up their mind based on their belief system & worldview, and just work their way back from that  pt. Have you ever seen one of th Conservative Scientists get reprimanded or even apologize for being so wrong in the 90s or early 00s? The science-based claims ridiculed by conservatives as alarmist in the 90s are way too conservative now, but those pp got ahead in their fields anyway bc they are useful to the Capitalists.

They will never be held responsible or accountable, and thus unlikely to ever change. They have all the social support they need, cheering them on that they are good ppl (lol). And they have the titles and money to help them reassure themselves that they are BETTER than you as scientists and human beings.
« Last Edit: July 23, 2019, 09:37:14 PM by TeaPotty »

Shared Humanity

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Re: When will the Arctic Go Ice Free?
« Reply #703 on: July 23, 2019, 09:49:04 PM »
I hold no illusions that Ken will eventually realize and voice any concerns about the impending disaster. My response to his comment was not intended to do that but is intended to help casual visitors to this site understand the errors in his argument that everything will be OK.

Everything will not be OK.

I understand how you are triggered by Ken but your responses only serve to scare away persons who visit here to get informed. Please don't take this observation personally. I often find myself reacting similarly and fight to restrain my need to attack in my comments. I am able to appear rational more often than not by delaying typing a response. This time is spent reviewing the comment and fashioning a response that points out the errors.

TeaPotty

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Re: When will the Arctic Go Ice Free?
« Reply #704 on: July 23, 2019, 10:01:01 PM »
I understand how you are triggered by Ken but your responses only serve to scare away persons who visit here to get informed. Please don't take this observation personally. I often find myself reacting similarly and fight to restrain my need to attack in my comments. I am able to appear rational more often than not by delaying typing a response. This time is spent reviewing the comment and fashioning a response that points out the errors.

I understand your sentiment, but still maintain that it’s misguided. Maybe your fellow academics are impressed with excessive restraint and politeness, but normal ppl are not. Normal ppl see passion as a sign of genuine concern and care, and the opposite as cowardice and hidden agendas.

We have to dare to speak truth to power, and call out those misleading others. Otherwise, they will continue to dominate narratives. For example, I was one of few here to pointed out that the IPCC conclusions will be weaponized by deniers for years. Which is exactly what happened.

HapHazard

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Re: When will the Arctic Go Ice Free?
« Reply #705 on: July 23, 2019, 10:32:09 PM »
This thread has taken one helluva nosedive recently.

jdallen

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Re: When will the Arctic Go Ice Free?
« Reply #706 on: July 23, 2019, 11:38:59 PM »
I also think Sam's numbered comments has it about right.
+1

Particularly this:
Quote
2) the transition is abrupt, though non-linearities soften that slightly. The first day, week or month of BOE isn't likely to cause the collapse. But, it won't take much more than that to cause an abrupt state transition in both the atmospheric and oceanic circulation with cataclysmic impact on the Earth's biota, fauna, and us. The transition is likely to take about 3-8 years. And with the beginning imminent in 3-8 years itself, that puts us ~11 years +/- ~6 years from that transition to a radically different system. Those are my guesstimates.

Your other comments have it about right also.
This space for Rent.

jdallen

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Re: When will the Arctic Go Ice Free?
« Reply #707 on: July 23, 2019, 11:45:18 PM »
This thread has taken one helluva nosedive recently.
It is the roar of frustration and fear, which I in every way understand, and which is in every way understandable.

I have great sympathy for Teapotty and Archimid. 

Any differences I have with them are nuance of detail, much like whether the curtains will burn before or after the windows blow out of the burning house we find ourselves in.

I don't discredit their feelings.  In fact, for the most part, I share them.
« Last Edit: July 24, 2019, 07:06:09 AM by jdallen »
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Sam

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Re: When will the Arctic Go Ice Free?
« Reply #708 on: July 23, 2019, 11:49:07 PM »
Let's return to the central issues...

1) When the Arctic will go ice free
2) How that is likely to play out from first ice free day, to week, to month, to season, to year
3) What the consequences are of that, and hence why we should care

1) the trends in ice extent, ice area and ice volume are all headed to the same outcome, zero ice. Each points to a somewhat different potential date for that. The differences in those dates, though important from a human perspective in a single human lifetime, are essentially identical in geologic terms, and virtually identical in the lifetime of civilizations or nations.

The most likely correct projection is the limiting projection based on the full suite of projections, not the average, not the last, but the first. And that is based on volume. The inherent oscillatory nature of the many linked earth and solar systems creates a form of variation that looks like and can useful be treated similar to randomness. And it has randomness in it. But it isn't truly random in the large scale.

That said, the outer bounds of the error band on projecting forward on ice volume suggest that we have already entered the outermost likelihood for an ice free summer day. Clearly this year won't be it. Next year could be. But most likely that won't be for a few years.

On the other end, the high band, we almost certainly will see it before 2030 even under the most unlikely combination of events. As a result, the first ice free day in September will almost certainly occur between 2022 and 2028.

2) with the progressive loss of ice cover, warming of the ice free ocean, thinning of the ice cover, failure of the tundra and clathrates, combined with mans continued and accelerating release of global warming gases, the lengths of time that the Arctic is essentially ice free will grow longer. There will be oscillation with temporary retreats, and with shocking extensions. The trend will remain for longer and longer ice free periods. That will happen quickly, even in human terms.

3) as that happens, the downwelling driving forces on both the ocean, driving the Atlantic and Pacific oceanic circulations will progressively grow weaker, and the down falling driving force for the atmosphere will simultaneously decline with it, and with that the motive forces for atmospheric circulation of the polar cell will decline.

As the oceanic driving forces collapse a whole suite of interlocking circulations will lose their motive force. New balances will come into play. The oceanic circulations will perhaps stall, and in some areas new broader slower circulations driven by corriolis forces and topography will take over. Areas will go anoxic. Species will move with the temperature and flow. Many will die.

As the atmospheric driving forces fail, the heat balance will shift. The tropopause will rise. The polar circulation will slow and become more chaotic before too be driven by lesser circulations and forces. As the polar cell fails, so too will the driving forces between the Ferrell and polar cells weaken and fail, then those between the Ferrell and Hadley cells. In time, those too will be overridden by other forces.

With an increased tropopause, single cell circulation becomes possible, though moving at slower speeds allowing drag to counter corriolis forces that would otherwise truncate the circulation. Exactly what happens with this is unknown and is a key question related to how the atmosphere circulates on Venus, and how it circulated on Earth during equable climate periods.

The oceanic and atmospheric circulations are however also interdependent based both on flow interactions and based on heat. With dramatic shifts in flow and consequent large shifts in heat balance, moisture shifts, clouds and the like, the problem is extraordinarily difficult to sort out.

That it will shift is certain.

As has already been noted, we are already seeing dramatic shifts in all of these, with dramatic consequences. However, the largest differences will no doubt come when the relative balance between the various forces reach near parity. At that point, if we had a non dimensional analysis to guide us, we might (and only might) have a better idea about how the transitions will occur, and precisely when we might expect hysteretic sorts of state change.

I haven't found a non dimensional analysis of the coupled ocean, air, ice thermodynamic system using the Buckingham Pi method that might aid there. If anyone does, that might be quite useful. It should tell us what the key dimensionless parameters are to monitor (essentially the ratios of various forces that drive the system as a whole).

What we can be certain of is that the Earth is a heat engine. During periods such as our recent several millions of years where we have ice at the poles, the heat differential between these and the solar inputs (dominant at the equator) act to stabilize the system like a giant engine. The ice acts as a huge buffer or battery holding the system in a sort of equilibrium. That oscillates annually and at longer periods. Still it is a buffer. With the loss of that buffer, the system loses its governor. It then is likely to change quite quickly to an alternate stable system governed by other dynamics. That is when we will,see and experience truly abrupt climate change. No one will need convincing then that it is real. But, no doubt, many will still need convincing that we are at fault, and that we need to urgently act.

That we don't know those dynamics sufficiently well to model them successfully is particularly troubling. That we know from geologic records just how different that system is is even more troubling. But, and this is especially important, people lose sight of the importance of the rate of change in converting from one to state to another. Prior geologic analogies seem tame and slow by comparison to our current predicament. And this may be why a period of ice free Arctic in and transition period between ice ages could exist without completely upending the system. Even then, the dynamics are such that the conditions must have been radically different from what we are acuustomed to.

In our case though, we don't have slow changes at work. Our case is more akin to a fully loaded 18 wheeler racing down a 12% grade, burning out its breaks and bashing through the guardrail into open air several thousand feet above the canyon floor. You might as well decide to enjoy the ever so brief ride, as no amount of steering or cranking on the breaks means anything at that point.

But in our analogy we are still on the road. We've begun to lose traction with the highway, the breaks are all but gone and the steering isn't working. Worse, we are making our decisions by committee with a crew in the cab that is, shall we say, less than up to the task.

We are in the ever so brief period before calamity where we cannot be quite certain whether we are going to inevitably go through the guard rail and plummet to our certain death, or miraculously gain the ever so small bit of control that allows us to steer onto the truck runaway ramp. Sure, it's going to rip the wheels off and all but destroy the rig, but at least we get to recover from it.

Now, if we can just get all of the monkeys in the cab to come to agreement that we need to act, and act together, maybe we might just barely survive this yet. But first we have to get them to stop biting each other and throwing their poo.

Sam


DrTskoul

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Re: When will the Arctic Go Ice Free?
« Reply #709 on: July 24, 2019, 12:43:58 AM »
Clathrates will take  muuuch longer. 

wili

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Re: When will the Arctic Go Ice Free?
« Reply #710 on: July 24, 2019, 01:08:11 AM »
Sam wrote: "...if we can just get all of the monkeys in the cab..."

Unfortunately even if we get nearly all the 'monkeys' in agreement, the one(s) driving the damn cab will still drive us over the damn cliff, since they are the insane .001% who mostly don't care about anything but $$$$$$$$$$$$$$$$$$$. :/

Thanks, though for the rest of your excellent post, especially this: "...With the loss of that buffer, the system loses its governor. It then is likely to change quite quickly to an alternate stable system governed by other dynamics. That is when we will,see and experience truly abrupt climate change...."

As has been said by many others many times better than I, uncertainty is not our friend, and flying into this sh!t storm relatively blind...not really able to model well what the likely outcomes are, should scare the b-jesus out of every living soul on the planet.

Dr. T--That does seem to be the view of man...but not all...specialists in that area. Certainly, thawing permafrost does now seem the more proximate (or rather immediate) carbon feedback threat.
« Last Edit: July 24, 2019, 01:19:18 AM by wili »
"A force de chercher de bonnes raisons, on en trouve; on les dit; et après on y tient, non pas tant parce qu'elles sont bonnes que pour ne pas se démentir." Choderlos de Laclos "You struggle to come up with some valid reasons, then cling to them, not because they're good, but just to not back down."

Ken Feldman

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Re: When will the Arctic Go Ice Free?
« Reply #711 on: July 24, 2019, 02:10:35 AM »
The UNFCC treaty signed in 1992 has the goal of keeping temperature increases below 2 degrees C globally.  This treaty also established the IPCC which produces scientific assessments of the effects of climate change.  The IPCC published an updated assessment in 2018 which reviews the impacts of an increase of 1.5C vs 2C.

I only quoted this one piece as your comment was quite long and, I might add, packed with useful info. I would encourage everyone to go back and read it so as to understand my response.

I am not here to refute what is said in the IPCC report. While I believe they error on the side of caution, this conservatism is not due to some subtle agenda but rather due to the method used to generate the report. It requires a consensus of all of the contributors, all of them far brighter and informed than me.

My objection to your post is grounded in one simple fact. We simply will not hold warming to 2C. This same IPCC report stated that we need to reduce global warming emissions 45% by 2030 and be carbon neutral by 2050 in order to avoid warming beyond 2C. Our BAU behavior virtually guarantees a 4C warmer world by 2100. This temperature increase has been described as incompatible with human civilization.

The reduction of 45% by 2030 and carbon neutral by 2050 is to keep warming under 1.5C.  I agree that probably wont happen.

Here's what the IPCC stated about reductions needed to stay under 2C:

Quote
In model pathways with no or limited overshoot of 1.5°C, global net anthropogenic CO2 emissions decline by about 45% from 2010 levels by 2030 (40–60% interquartile range), reaching net zero around 2050 (2045–2055 interquartile range). For limiting global warming to below 2°C11 CO2 emissions are projected to decline by about 25% by 2030 in most pathways (10–30% interquartile range) and reach net zero around 2070 (2065–2080 interquartile range). Non-CO2 emissions in pathways that limit global warming to 1.5°C show deep reductions that are similar to those in pathways limiting warming to 2°C. (high confidence) (Figure SPM.3a) {2.1, 2.3, Table 2.4}

My speculative guess is that we'll wind up between 1.5C and 2C.  I'm guessing that a BOE will first occur in the late 2020s and it won't have much more impact than our low extent fall of 2012 had.  I base that on a lot of reading (and talking to some researchers who have studied the Arctic ice).

For the record, I'm neither a boomer nor an academic.  Just someone who cares.  I dislike seeing people who have given up hope trying to take it from those of us who are still trying to make positive changes.

crandles

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Re: When will the Arctic Go Ice Free?
« Reply #712 on: July 24, 2019, 02:22:57 AM »
We have been through this. And we have been through this exhaustively.

The ideas are simple.

1) the models we have are largely based on the quasi steady state conditions that man evolved under, and specifically the last two centuries of data. They are not great for predicting the precise effects of transition to a new state in conditions we have never observed. Translation: Real world... the models dramatically under predict the speed and consequences of the transition. Real world... the models fail to fully incorporate key aspects of the actually quite straght forward thermodynamics. Earth's climate is a heat engine. Remove the cold pole and the heat engine dies. With that the atmospheric and oceanic driving forces either die or are greatly altered - rapidly...  Real world... no model yet has been able to adequately model the known paleoclimatic conditions of the equable climate system that results.  But we do know what that looks like. And it is radically different from the state know now. We also know that a rapid transition from one to the other is fatal for most creatures on earth. The PETM involved a different though similar transition and serves as one of our best unserstood exemplars. Real world... the IPCC has grossly under estimated the speed and severity of the transition to our great peril, and simultaneously painted roses cheeks on how hard it is to prevent this transition. It is now long since too late.

2) the prove it to me, and until you do it isn't true, argument is a loser. That's not how things work. Sadly it all too often is how humans work, with tragic consequences.

As to papers...  here is a non-representative sample of a few to highlight both some of the issues and the extent of time we've known these things. These do not form a complete argument. They are only examples. For full citations, check the papers.

Nonlinear threshold behavior during the loss of Arctic sea ice
https://www.pnas.org/content/106/1/28
https://www.pnas.org/content/pnas/106/1/28.full.pdf

A Numerical Study of Sea Ice and Ocean Circulation in the Arctic
https://journals.ametsoc.org/doi/pdf/10.1175/1520-0485%281987%29017%3C1077%3AANSOSL%3E2.0.CO%3B2?download=true

Future abrupt reductions in the summer Arctic sea ice
https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2006GL028024

Some results from a time‐dependent thermodynamic model of sea ice
https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/JC076i006p01550

Fast Response of the Tropics to an Abrupt Loss of Arctic Sea Ice via Ocean Dynamics
https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2018GL077325

So, what can we glean from these handfull of citations?

1) the transition is chaotic and non linear with massive impacts on oceanic and atmospheric circulation
2) the transition is abrupt, though non-linearities soften that slightly. The first day, week or month of BOE isn't likely to cause the collapse. But, it won't take much more than that to cause an abrupt state transition in both the atmospheric and oceanic circulation with cataclysmic impact on the Earth's biota, fauna, and us. The transition is likely to take about 3-8 years. And with the beginning imminent in 3-8 years itself, that puts us ~11 years +/- ~6 years from that transition to a radically different system. Those are my guesstimates.
3) the consequences of that rapid transition quickly flow through the Earth's oceans, atmosphere, and biosphere with effects in the tropics in ~25 years. So ~36 years +/- ~ a decade from now. That is an absolute blink in geologic time.
4) we are in deep trouble. If you aren't terrified you aren't paying attention, or you just don't care, or you are in fear and simple blind denial. Take your pick.

Sam

I haven't fully read all of these papers only done a quick review. Also I am not an academic or expert, just interested in climate modelling and Arctic sea ice. I could easily be misinterpreting the papers. Feel free to correct me if/where I am missing or misinterpreting the papers.

Nonlinear threshold behavior during the loss of Arctic sea ice” is a 2008 paper on nonlinear behaviour. It’s abstract includes:
“the stabilizing thermodynamic effects of sea ice mitigate this when the Arctic Ocean is ice covered during a sufficiently large fraction of the year. These results suggest that critical threshold behavior is unlikely during the approach from current perennial sea-ice conditions to seasonally ice-free conditions. In a further warmed climate, however, we find that a critical threshold associated with the sudden loss of the remaining wintertime-only sea ice cover may be likely.”

So it is saying no non-linearity prior to a BOE but there may well be some considerable time after. There is little indicating how large a ‘sufficiently large fraction of the year’ is except perhaps for this passage:
“However, perennially ice-free Arctic Ocean conditions occur in 2 of the model simulations after CO2 quadrupling. Neither of the models exhibits an abrupt transition when the annual minimum (September) ice cover disappears, but after further warming 1 of the models abruptly loses its March ice cover when it becomes perennially ice free (26). The physical mechanism presented here may help explain this abrupt simulated loss of March ice following the gradual simulated loss of September ice.”

I think we are several decades if not 100+ years away from losing April Ice cover. Similarly CO2 quadrupling is also a long way off. That doesn’t mean it couldn’t happen earlier but the implications of what is included in the paper seems much more 'well after a BOE' than the timeline Sam seems to indicate.

Also note IPCC report saying

a substantial number of pre-AR5 studies have found that there is no indication of hysteresis behavior of Arctic sea ice (Holland et al., 2006; Schroeder and Connolley, 2007; Armour et al., 2011; Sedláček et al., 2011; Tietsche et al., 2011; Boucher et al., 2012; Ridley et al., 2012). In particular, the relationship between Arctic sea-ice coverage and GMST is found to be indistinguishable between a warming scenario and a cooling scenario. These results have been confirmed by post-AR5 studies (Li et al., 2013; Jahn, 2018)

That is more studies, generally later than 2008. This might be an indication that IPCC is downplaying possibility of nonlinear behaviour, or maybe the later studies are considered more reliable or maybe IPCC were aware of it but since it is so far into future, well past 1.5C or 2C of warming, it was appropriate to downplay the possibility in such a report. Different people might reach different conclusions depending how much esteem they think IPCC deserves.


A Numerical Study of Sea Ice and Ocean Circulation in the Arctic
A 1986 paper. Abstract seems to say Arctic sea ice is vulnerable to CO2 increases but not to river discharge. I don’t think anyone in this forum is saying that CO2 does not have effect on Arctic sea ice level. So I am a bit puzzled as to why this paper has been included.

Future abrupt reductions in the summer Arctic sea ice
“find that abrupt reductions are a common feature of these 21st century simulations. These events have decreasing September ice extent trends that are typically 4 times larger than comparable observed trends. One event exhibits a decrease from 6 million km2 to 2 million km2 in a decade, reaching near ice‐free September conditions by 2040.”

https://wol-prod-cdn.literatumonline.com/cms/attachment/7385a142-4b4f-447d-8efb-2d27c740df4b/grl22398-fig-0001.png

This model had about 6m km^2 extent in 2000. The extent remained constant til about 2025 then reduced to 2m km^2 in a decade. It then levels out having about 1m km^2 in 2050 and continues to have some ice in September off and on up to 2100.
Yes 4m km^2 loss in a decade is fast. 2007 to 2012 lost less than 1m km^2 in 5 years so twice as fast as that. Yes that is rapid. If it is a lot less rapid before and after, is this really hugely significant? If we jump down from 4m km^2 to 0 in the next decade and then start seeing huge consequences of the BOEs perhaps it could be, but continuing very small amounts of Sept sea ice extents for 50 years after we get down to 1m km^2 does not seem to back up what is being suggested.


Some results from a time‐dependent thermodynamic model of sea ice
A 1971 paper, one dimensional model. Early days of modelling. Umm what are you taking from this? Wouldn’t you rather results from more recent models?

Fast Response of the Tropics to an Abrupt Loss of Arctic Sea Ice via Ocean Dynamics
Compares a simple slab ocean model to a more dynamic model. Concludes “This fast response indicates that ocean dynamics needs to be represented for an accurate picture of the global impact of Arctic sea ice loss.”

So it would be nice if we could get away with a simpler model but we can’t. The more realistic dynamic model has much smaller changes in SST in Northern Hemisphere and precipitation in most places. SST increases in Southern hemisphere are more pronounced. The strong SST warming pattern in eastern equatorial pacific looks quite El Nino like so could be getting stronger or longer lasting El Ninos. Reduced precipitation over Amazon might be rather concerning even if it is hatched indicating not statistically significant.

My notes seem rather different from the conclusions Sam seems to have gleaned.

Perhaps someone can point out a few of the things I have missed from these papers and explain why our notes are so different.

Sorry the post is so long.

Shared Humanity

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Re: When will the Arctic Go Ice Free?
« Reply #713 on: July 24, 2019, 03:41:13 AM »
The reduction of 45% by 2030 and carbon neutral by 2050 is to keep warming under 1.5C.  I agree that probably wont happen.

Here's what the IPCC stated about reductions needed to stay under 2C:

Quote
In model pathways with no or limited overshoot of 1.5°C, global net anthropogenic CO2 emissions decline by about 45% from 2010 levels by 2030 (40–60% interquartile range), reaching net zero around 2050 (2045–2055 interquartile range). For limiting global warming to below 2°C11 CO2 emissions are projected to decline by about 25% by 2030 in most pathways (10–30% interquartile range) and reach net zero around 2070 (2065–2080 interquartile range). Non-CO2 emissions in pathways that limit global warming to 1.5°C show deep reductions that are similar to those in pathways limiting warming to 2°C. (high confidence) (Figure SPM.3a) {2.1, 2.3, Table 2.4}


Ken...you challenged someone for not reading the IPCC report that you linked to. Did you even read the quote you pulled from the report before you posted this comment? The bold underlined text has been highlighted by me.

Also please take a look at this linked chart...

https://ourworldindata.org/grapher/annual-co-emissions-by-region

...and explain to me where you think we will get a 11 billion ton reduction in annual CO2 emissions in the next decade in order to keep warming below 2C, given the current trends.

At best, emissions in 2030 will match emissions in 2019 and that is only if we start doing things we are not yet doing. We are not going to hold temp gains below 2C, not even close.
« Last Edit: July 24, 2019, 04:25:10 AM by Shared Humanity »

binntho

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Re: When will the Arctic Go Ice Free?
« Reply #714 on: July 24, 2019, 04:14:14 AM »
My notes seem rather different from the conclusions Sam seems to have gleaned.
Exactly! Thanks for laying this out,  I myself didn't really have time to do more than scan and dismiss rapidly.

Before anybody starts making incredibly long-winded speculations about the consequences of a BOE they might start by explaining how the last 15-20 or so BOE did not have these same consequences.

And almost all of these BOE happened while our ancestors were developing in the African Savanna.

And Human Sapiens has so far lived through at least 2 if not 3 BOE and survived happily (!).

So enough with 1000 words speculations, how about some real cience?
because a thing is eloquently expressed it should not be taken to be as necessarily true
St. Augustine, Confessions V, 6

binntho

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Re: When will the Arctic Go Ice Free?
« Reply #715 on: July 24, 2019, 04:18:13 AM »
I also think Sam's numbered comments has it about right.
+1

Particularly this:
Quote
2) the transition is abrupt, though non-linearities soften that slightly. The first day, week or month of BOE isn't likely to cause the collapse. But, it won't take much more than that to cause an abrupt state transition in both the atmospheric and oceanic circulation with cataclysmic impact on the Earth's biota, fauna, and us. The transition is likely to take about 3-8 years. And with the beginning imminent in 3-8 years itself, that puts us ~11 years +/- ~6 years from that transition to a radically different system. Those are my guesstimates.

Your other comments have it about right also.

I trust you are being sarcastic? How did the last 15-20 BOE not have a "cataclysmic impact on the Earth's biota, fauna" and the last 3 on "us", but this one will?

And how can you take seriously someone who posts lots of links to peer reviewed papers that do not agree with what he is saying, and then "guesstimates" the time it takes the global climate to undergo incredible, severe and cataclysmic changes to a few years.

Is this some sort of end-of-world cultism that has taken hold in this thread?
because a thing is eloquently expressed it should not be taken to be as necessarily true
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DrTskoul

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Re: When will the Arctic Go Ice Free?
« Reply #716 on: July 24, 2019, 04:29:30 AM »
How do you know they did not have a "cataclysmic" effect. Is there a measure of the distribution of species before and after to understand what has been the impact. Nobody says the earth system will cease to exist...but if a large amount of current species is disturbed or goes extinct due to such an event that would be a cataclysmic change....
« Last Edit: July 24, 2019, 04:35:15 AM by DrTskoul »

wili

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Re: When will the Arctic Go Ice Free?
« Reply #717 on: July 24, 2019, 04:36:29 AM »
The Last Time the Arctic Was Ice-Free in the Summer, Modern Humans Didn’t Exist

https://slate.com/technology/2014/12/the-last-time-the-arctic-was-ice-free-in-summer-modern-humans-didn-t-exist.html

By Eric Holthaus

Full study:
https://www.nature.com/articles/ncomms6608
"A force de chercher de bonnes raisons, on en trouve; on les dit; et après on y tient, non pas tant parce qu'elles sont bonnes que pour ne pas se démentir." Choderlos de Laclos "You struggle to come up with some valid reasons, then cling to them, not because they're good, but just to not back down."

Coffee Drinker

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Re: When will the Arctic Go Ice Free?
« Reply #718 on: July 24, 2019, 04:41:36 AM »
Our flora and fauna is not in a natural state anymore. In the past ecosystems were intact and species could migrate freely with the climate. Now they are perched into national parks and little island like refuges. Apart from few places, natural migrations are simply not possible anymore.


wili

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Re: When will the Arctic Go Ice Free?
« Reply #719 on: July 24, 2019, 04:54:48 AM »
Good points, CD.

Some further points here:

 Global impacts


Quote
On a larger scale, the biggest impact may be the changes in the Arctic's ability to function as a cooling system for the global ocean. Both the Pacific and Atlantic now have warmer waters from the top to the bottom, based on measurements from computerized floats. The Arctic has been functioning as a global air conditioner, losing roughly 350 watts of heat per square meter of open ocean to the atmosphere during the fall storm season as well as the early part of the winter. A warmer Arctic may not be able to shed those greater amounts of heat.

That inability, in turn, will affect the temperature differences between the northern polar region and areas further south. In the atmosphere, it is that temperature gradient that creates and sustains the jet stream—a band of high winds at altitude flowing from west to east that typically steers weather systems in the Northern Hemisphere. "The jet stream becomes more kinked," NSIDC's Meier notes, which allows cold air to spill further south or warm air to penetrate further north.

The loss of this temperature gradient may also stall weather patterns within the jet stream, allowing particular weather systems to park for a while in one place. That may, in turn, create stronger heat waves and droughts or precipitation. "If it's a rain pattern that gets stuck in place, you get flooding that becomes a problem," Meier says.

As other parts of the article point out, we really don't have a clear idea about what will happen, either from models nor paleo-data. This is likely going to happen faster than in earlier periods, so it's not clear that paleo-data, whatever exists, will be all that helpful in figuring out the immediate impacts of such a rapid change.

And of course the world and human life is very, very different in many ways than it was millions of years ago (which should be so blindingly obvious, I'm rather embarrassed to have to state it here).

https://www.scientificamerican.com/article/arctic-sea-ice-loss-implications/

More from the same article:

Model failure

Quote
Regardless of what the Arctic meltdown reveals, what is increasingly clear is that the computer models that scientists rely upon to make predictions have failed to capture the rapid pace of change in the far north. The problem stems from spatial resolutions that are too large—a single grid in a typical computer model encompasses 100 square kilometers—to "see" small but important features such as warm ocean water currents or ice export. And the computing capacity is insufficient to render Arctic cyclones and the role they play in breaking up the ice. "Are the models still too conservative or not?"...

"We're moving into new territory and the impacts of that are unknown scientifically."
« Last Edit: July 24, 2019, 05:00:05 AM by wili »
"A force de chercher de bonnes raisons, on en trouve; on les dit; et après on y tient, non pas tant parce qu'elles sont bonnes que pour ne pas se démentir." Choderlos de Laclos "You struggle to come up with some valid reasons, then cling to them, not because they're good, but just to not back down."

wili

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Re: When will the Arctic Go Ice Free?
« Reply #720 on: July 24, 2019, 05:06:20 AM »
More recent:

https://www.theverge.com/2018/5/10/17339046/arctic-sea-ice-decline-albedo-effect-climate-change-global-warming

"The albedo effect due to vanishing sea ice is already responsible for about 25 percent of global warming"

Also discusses slr, jetstream disruption, permafrost loss w carbon feedback...Quoting J. Francis and other scientists.

Further:

Quote
Ice-free summers in the Arctic Ocean “would radically affect global weather patterns and dramatically increase the magnitude and frequency of storm events. It would also dramatically alter the Arctic marine ecosystem, with the added sunlight affecting the Arctic Ocean food web and melting the very ice bed on which animals like polar bears hunt,” says John Yackel, professor of geography, University of Calgary.

https://www.downtoearth.org.in/coverage/climate-change/ice-free-arctic-sea-may-happen-much-sooner-than-predicted-so-far-study-58927

https://www.downtoearth.org.in/news/climate-change/ice-free-arctic-this-summer-a-possibility-signalling-drastic-climate-change-54245

(Are we really having this conversation here?)


« Last Edit: July 24, 2019, 05:14:16 AM by wili »
"A force de chercher de bonnes raisons, on en trouve; on les dit; et après on y tient, non pas tant parce qu'elles sont bonnes que pour ne pas se démentir." Choderlos de Laclos "You struggle to come up with some valid reasons, then cling to them, not because they're good, but just to not back down."

Sam

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Re: When will the Arctic Go Ice Free?
« Reply #721 on: July 24, 2019, 05:28:21 AM »
I also think Sam's numbered comments has it about right.
+1

Particularly this:
Quote
2) the transition is abrupt, though non-linearities soften that slightly. The first day, week or month of BOE isn't likely to cause the collapse. But, it won't take much more than that to cause an abrupt state transition in both the atmospheric and oceanic circulation with cataclysmic impact on the Earth's biota, fauna, and us. The transition is likely to take about 3-8 years. And with the beginning imminent in 3-8 years itself, that puts us ~11 years +/- ~6 years from that transition to a radically different system. Those are my guesstimates.

Your other comments have it about right also.

I trust you are being sarcastic? How did the last 15-20 BOE not have a "cataclysmic impact on the Earth's biota, fauna" and the last 3 on "us", but this one will?

And how can you take seriously someone who posts lots of links to peer reviewed papers that do not agree with what he is saying, and then "guesstimates" the time it takes the global climate to undergo incredible, severe and cataclysmic changes to a few years.

Is this some sort of end-of-world cultism that has taken hold in this thread?

Binntho,

Consider several things please. Much as I wish I were, I am not at all being sarcastic.

1) we do not know or understand exactly how the climate behaved with a slow approach to a blue ocean event. Our models seem incapable of creating conditions that support the array of facts we know. Now, we may have our facts wrong, or more likely we are missing major factors and ideas in the models ... e.g. if the atmospheric circulation collapses and goes to a unicellular system with intense and pervasive winter cloud cover, that might fit with the data. I am not offering that as THE explanation. Neither did that originate with me.

2) what we have now is anything but a slow approach to a BOE. We are racing up to it at break neck speed by pumping immense amounts of warming gases into the atmosphere. That wasn’t present in the events I think you are referencing. Not knowing precisely which events you are referencing, I cannot say that with confidence. {hint: please post references to the events, so that we don’t have to either guess, or attempt to read your mind}. And it will not stop as we reach the BOE. We have heavily overdriven the system.

3) scientists, researchers, engineers and others work to interpret data in messy often seemingly conflicting data sets all of the time. It is rare that we have perfect data. It is common to have really messy noisy data. It is equally common to have conflicting views and interpretations and to need to work through those. 

4) as I noted, the papers I referenced are not sufficient in themselves to build a closed logical case. Neither do they represent the entire field of study, or the range of observations. What they do is highlight some of the key processes at work: oceanic and atmospheric circulation being driven by thermodynamics, and the long range rapid impacts that occur when those systems are broken.

5) within those there are several conclusions and estimates. These include
A) an estimate of 3-8 years to reach an initial BOE. Is that right? Many will argue in different directions for differing reasons. But, the ice volume will be the driver. The trends there support a first BOE day occurring anytime from next year to sometime after mid-decade. The most likely appears to be 2022-2023. That would make the range 1-7 years. Close enough.
B) an estimate for the time from that first occurrence until the impacts are large enough to make pervasive changes in the arctic circulation systems and dynamics (my restatement of their info, not a quote) of 3-8 years. That seems about right based on many studies. The first year seems unlikely to have a long ice free time. Ditto the second. Once that builds to a couple of months though the impacts are likely to grow exponentially with ice free time. Combine these and the full range is 6-16 years. Hence my reduction to 11 +/-6 as my guesstimate. Perhaps that should be 11 +/-5. I slipped by a year.
C) the article on the large scale impact to the tropics suggests that it is likely to be 25 years (give or take) after the arctic impacts are significant. Are these referencing the identical states? Almost certainly not. Are they close? Yes. Ok, so 11 + 25 = 36 years from now (give or take) should be about when we see large scale changes -beginning- in the tropics.
D) none of this works like a light switch. Sudden does not mean instantaneous. Neither does it mean going fully from one state to another. That will take longer. Buffering of large ice masses in the Antarctic and Greenland will assure that. But failure of tundra areas and forests from fires, insects, and drought will speed that. It is all going to get messy and harsh. And right on cue what do we have? Giant fires on the tundra in Russia, Canada and Alaska, giant forest fires, insect infestations, drought due back of forests and worse.

I know (or strongly suspect) that you don’t like the required changes that are needed to try to slow these impacts, and that you don’t want to believe they are coming. I am tempted to say “I’m sorry”, but that is meaningless. That is just a human response to comfort suffering. The truth sadly is that the suffering is unfortunately necessary. It is a part of going through cognitive dissonance. The reality you see is disagreeing with what you believe and want. Only one of those is going to yield. {hint: it isn’t reality; it is your beliefs and desires- all of ours actually.} We’ve all had to go through this. And it will get much more difficult before it can feel any better. But, it won’t ever feel better. We’ve destroyed our world, at least the world as we’ve known it.

What we are beginning to debate is just how fast and severe the changes will be, and whether and how much we may be able to slow those changes. For now, it is still perhaps possible to avoid driving the world to a hot house state. But, perhaps not.

Clearly we have entered the sixth great extinction event. Sadly it seems many of our leaders want us to be number 1. They seem not to understand that being number 1 is losing, not winning in this contest. Will all of those species promptly die in 36 years? Of course not. But too a very large degree their ultimate demise will be locked in by then. The actual process to destroy everything will take longer.

And once complete, the Earth will recover better than before. Over the next million years there will be a vast explosion of evolutionary shifts as creatures and plants fill all the empty places in the biosphere with new experiments in adaptation. That will be glorious, even if it involves no primates at all.

Sam
« Last Edit: July 24, 2019, 05:33:58 AM by Sam »

binntho

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Re: When will the Arctic Go Ice Free?
« Reply #722 on: July 24, 2019, 05:39:01 AM »
The Last Time the Arctic Was Ice-Free in the Summer, Modern Humans Didn’t Exist

https://slate.com/technology/2014/12/the-last-time-the-arctic-was-ice-free-in-summer-modern-humans-didn-t-exist.html

By Eric Holthaus

Full study:
https://www.nature.com/articles/ncomms6608

Well, the full study does not say that. Nor does it allow for that conclusion. The full study says that the Arctic became frozen over  some 4 million years ago, but it does not say anything about eventual BOEs happening during interglacials that happen roughly every 100 - 100.000 years.

I belive there is a general consensus that the last interglacial (LIG) had ice-free summers and various claims that the current (Holocene) interglacial maximum (HIM) also had ice-free summers.

The oft-cited Nature article does not support this (https://www.nature.com/articles/s41467-017-00552-1) based on sediments, while their projections for the current warming are somewhat spurious (they do see a BOE event at around 2300).

Many other articles do however point to an ice-free or near-ice-free Arctic in the LIG (e.g. https://iopscience.iop.org/article/10.1088/1755-1307/6/7/072002/pdf) but probably one of the best is this one (https://www.researchgate.net/publication/222022772_History_of_sea_ice_in_the_Arctic)

One of the most intriguing findings of that last article (I think) is the signs of wave action on the northern coast og Greenland during HIM - and how can that happen without a BOE?

Ossifrage, in his excellent post on the melting season thread also points out the totally different state of ice at the HIM than today.

But all studies agree that LIG was a lot warmer in the Arctic than today, and even HIM was significantly warmer in the Arctic than today. If no BOE happened then, how likely is one to happen now?

So it seems that based on the literature, the older and larger corpus goes for 2 or 3 BOEs after the appearance of modern humans. Other researches that doubt the recent BOEs, on the other hand, does not allow for an imminent BOE now.
because a thing is eloquently expressed it should not be taken to be as necessarily true
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binntho

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Re: When will the Arctic Go Ice Free?
« Reply #723 on: July 24, 2019, 05:42:40 AM »
How do you know they did not have a "cataclysmic" effect. Is there a measure of the distribution of species before and after to understand what has been the impact. Nobody says the earth system will cease to exist...but if a large amount of current species is disturbed or goes extinct due to such an event that would be a cataclysmic change....
If we assume that BOE events have happened during the last interglacials (and even during this current interglacial maximum) then, the answer is that there is no sign of any cataclysmic consequences.

The very large consequences of going from the deep freeze of a glacial to the balmy weathers of an interglacial are, on the other hand, obvious. But those changes took a very long time (several thousands of years, with a rate of varming proably 1/10th of what it is today).

So the cataclysmic effects of current warming are indeed serious. There are no cataclysmic effects of a BOE.
because a thing is eloquently expressed it should not be taken to be as necessarily true
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binntho

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Re: When will the Arctic Go Ice Free?
« Reply #724 on: July 24, 2019, 05:44:17 AM »
Our flora and fauna is not in a natural state anymore. In the past ecosystems were intact and species could migrate freely with the climate. Now they are perched into national parks and little island like refuges. Apart from few places, natural migrations are simply not possible anymore.
Absolutely right, which is what makes the current global warming so totally frightening and potentially calamitous.

We do not need a BOE to cause major disruptions, we are already causing them and they will get progressively worse.
because a thing is eloquently expressed it should not be taken to be as necessarily true
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binntho

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Re: When will the Arctic Go Ice Free?
« Reply #725 on: July 24, 2019, 05:55:39 AM »
Sam, I did not think you were being sarcastic. I was hoping that jdallen was.

And these huge speculative musings do nothing to support your claims.

As for the BOEs in the past, I think I have made it extremely clear several times what I am talking about:

1) At the current Holocene maximum, about 8000 years ago.
2) At the last interglacial, about 120.000 years ago.
3) At (most) all of the previous interglacials, appr. every 120.000 years for 3 million years.

So that's a lot of BOEs, and there is quite a lot of peer-reviewed arcticles that support this.

Although, as I pointed out a few posts back, there are peer-reviewed articles that indicate that there may not have been BOEs at 1) and 2) (and presumably not at 3) either), in spite of the Arctic being a hell of a lot warmer than it is today.

If so, then a BOE is nowhere near imminent.

B) an estimate for the time from that first occurrence until the impacts are large enough to make pervasive changes in the arctic circulation systems and dynamics (my restatement of their info, not a quote) of 3-8 years. That seems about right based on many studies. The first year seems unlikely to have a long ice free time. Ditto the second. Once that builds to a couple of months though the impacts are likely to grow exponentially with ice free time. Combine these and the full range is 6-16 years. Hence my reduction to 11 +/-6 as my guesstimate. Perhaps that should be 11 +/-5. I slipped by a year.
Well these year guesses are totally ridiculous. Add a zero or two and we might start to look at them seriusly.
because a thing is eloquently expressed it should not be taken to be as necessarily true
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wili

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Re: When will the Arctic Go Ice Free?
« Reply #726 on: July 24, 2019, 06:04:47 AM »
binntho, I am assuming by LIG you mean Eemian (even though technically the Holocene is the last, and Eemian is the penultimate :).

Note:
Quote
The prevailing Eemian climate was, on average, around 1 to 2 degrees Celsius (1.8 to 3.6 Fahrenheit) warmer than that of the Holocene. However, due to global warming, the past few July global temperatures likely surpassed the (long-term average) July temperatures of the Eemian period. During the Eemian, the proportion of CO2 in the atmosphere was about 280 parts per million

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

https://mashable.com/2018/08/27/earth-warmest-temperatures-climate-change/

Speed of change is a big thing, too, for the ability of creatures and the systems that support them to adapt.

As we have seen, the there can be cracks in the ice along Greenland, and presumably these will widen quite a bit, allowing waves to crash again on its shores, before the Arctic is in full BOE.

I sited a number of scientists who straight out said that a (near) ice free Arctic would be a very big deal with many dramatic consequences. Do you just flat out disagree with all of those scientists?

(Apologies ahead of time. It's past my bedtime, so I probably won't respond further till tomorrow sometime. Sleep tight, one and all! And stay cool, all you Europeans in the jaws of that heatwave!)

"A force de chercher de bonnes raisons, on en trouve; on les dit; et après on y tient, non pas tant parce qu'elles sont bonnes que pour ne pas se démentir." Choderlos de Laclos "You struggle to come up with some valid reasons, then cling to them, not because they're good, but just to not back down."

binntho

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Re: When will the Arctic Go Ice Free?
« Reply #727 on: July 24, 2019, 06:17:22 AM »
binntho, I am assuming by LIG you mean Eemian (even though technically the Holocene is the last, and Eemian is the penultimate :).
Well, I found these acronyms in one of the articles. The Eemian was indeed the last interglacial (as in Wednesday the 17th  was last Wednesday) while the Holocene is the current interglacial.

Penultimate means, I think, the second to last. So with an active event, the last is also the penultimate. When the current interglacial has run it course (if ever ...) then the Eemian is still the penultimate, but the Holocene has become the last.
Quote
Note:
Quote
The prevailing Eemian climate was, on average, around 1 to 2 degrees Celsius (1.8 to 3.6 Fahrenheit) warmer than that of the Holocene. However, due to global warming, the past few July global temperatures likely surpassed the (long-term average) July temperatures of the Eemian period. During the Eemian, the proportion of CO2 in the atmosphere was about 280 parts per million

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

https://mashable.com/2018/08/27/earth-warmest-temperatures-climate-change/
Well, yes, but all the literature agrees that the Arctic was a hell of a lot warmer, it is easy to find 4 and 8 and even 9 degrees as estimates for temperatures above the current.
Quote
As we have seen, the there can be cracks in the ice along Greenland, and presumably these will widen quite a bit, allowing waves to crash again on its shores, before the Arctic is in full BOE.
Really?
Quote
I sited a number of scientists who straight out said that a (near) ice free Arctic would be a very big deal with many dramatic consequences. Do you just flat out disagree with all of those scientists?
Well, you had links to a couple of articles on Downtoearth.com - is that what you mean? Those articles do not support that a BOE will have cataclysmic effects, so I sort of ignored them as having been a mistake on your part.
Quote
(Apologies ahead of time. It's past my bedtime, so I probably won't respond further till tomorrow sometime. Sleep tight, one and all! And stay cool, all you Europeans in the jaws of that heatwave!)
Well it's a balmy 24C here at sunrise, wasn't really possible to sleep with a broken airconditioner (*!#) ... but I'll take a dip in the ocean later to cool down! Sleep tight!
because a thing is eloquently expressed it should not be taken to be as necessarily true
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jdallen

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Re: When will the Arctic Go Ice Free?
« Reply #728 on: July 24, 2019, 07:36:41 AM »

I trust you are being sarcastic? How did the last 15-20 BOE not have a "cataclysmic impact on the Earth's biota, fauna" and the last 3 on "us", but this one will?

<snip>

Is this some sort of end-of-world cultism that has taken hold in this thread?
Not sarcastic.

Maybe I was misreading what Sam and Tor were saying.

And actually, climate impacts are already cataclysmic, something with which I think you agree, when you look at the extinction rate and unfolding effects showing up not just in the Arctic but elsewhere.

My point was and still is, the BoE by itself will be more of an effect than a cause, which will be led up to by events that will insure it takes place, and which in total will be as important if not more important causes of the changes we will see play out over the next few decades.  We are mostly fiddling over where to put the slider for a specific date; in my case, that's 2029/2030 or so.  And as some others have suggested, I don't think BoE levels of September ice will become typical until much later in the century. 

How soon that happens hinges much more on how fast the Arctic Ocean proper heats up, rather than just the ice.  Greenland will have a role to play in that as well, and as such will continue to buffer changes for several more centuries.  2.9 million km3 of ice is a lot less volatile than 4-17 thousand.  Long term the question in my mind is, whether humanity will be smart enough and retain enough science and capability to leverage that usefully.



I'm not in any cult, I'm reading what's published and watching what the satellites tell us, and applying a lifetime of study, observation and analysis.

We need desperately to get to zero emissions.

(Edit:  I must have missed something - you have any specific citations for Eemian and Holocene BoE's to throw at me?  Last I'd thought was most of those had been questioned? I'll dig around as well.)
« Last Edit: July 24, 2019, 07:45:52 AM by jdallen »
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binntho

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Re: When will the Arctic Go Ice Free?
« Reply #729 on: July 24, 2019, 07:59:35 AM »

I trust you are being sarcastic? How did the last 15-20 BOE not have a "cataclysmic impact on the Earth's biota, fauna" and the last 3 on "us", but this one will?

<snip>

Is this some sort of end-of-world cultism that has taken hold in this thread?
Not sarcastic.
...
Well I tend to be more tongue in cheek than not.

And I think we are mostly in agreement as you yourself point out.

With all the noise I'm not surprised that you've missed what I posted earlier, with links to various papers, including one that seems to dismiss BOE in both the Eemian and the Holocene.

But there are more papers that can be found online that point in another direction, and the remains of wave action along the north coast of Greenland from the Holocene Maximum is strongly indicative of a BOE.

And the opposite point: If there were no BOEs in this or recent interglacials when the Arctic was significantly warmer than it is today, then a BOE is by the same token not very likely in the next few decades.
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Coffee Drinker

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Re: When will the Arctic Go Ice Free?
« Reply #730 on: July 24, 2019, 08:32:37 AM »
I think a BOE can happen any year now. Not as the new normal but as an outlier like 2012 was. You just need one year with the perfect conditions to align. Poor winter ice formation. Plenty of sun during peak insulation and heavy storms before and after that. I don't think a single BOE will cause the whole system to go into full disaster mode. The following years could easily recover and follow  the normal decline path until BOE's become the normal a decade or so later.

I guess, once BOE are the new norm, the next milestone would be real BOE. Meaning absolutely zero ice in September.

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Re: When will the Arctic Go Ice Free?
« Reply #731 on: July 24, 2019, 08:34:28 AM »
I think a BOE can happen any year now. Not as the new normal but as an outlier like 2012 was. You just need one year with the perfect conditions to align. Poor winter ice formation. Plenty of sun during peak insulation and heavy storms before and after that. I don't think a single BOE will cause the whole system to go into full disaster mode. The following years could easily recover and follow  the normal decline path until BOE's become the normal a decade or so later.
Agree.
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Re: When will the Arctic Go Ice Free?
« Reply #732 on: July 24, 2019, 09:25:02 AM »
The problem is that we don't have good models to have reliable predictions when a BoE will happen and what the effect of a BoE will be.

Will there be feedback mechanism kicking in, 'restoring' the ice?


Huh?

When on a human time-scale; IPCC says when we stick to 1.5 degree, it will be once in a 100 years. Seeing the trend, I've got problems to believe them. I've also seen studies that say it will happen earlier. And as you can see in this thread people and researches tend to differ on the effects of a BoE on the climate. I've said 3 options that all have papers supporting them.

That fact gives me the impression that we, as humanity, have lot's of trouble with making reliable models concering BoE

Edit:
I think BoE in the discussion in the last couple of days isn't <1M km2 ice, but the moment air temperature isn't limited by the ice anymore.
Dropping below 1M km2 will be just another sad milestone on the path of climate change/global warming, but I doubt anyone here believes that will trigger almost instant destruction/doom.
« Last Edit: July 24, 2019, 09:50:08 AM by RikW »

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Re: When will the Arctic Go Ice Free?
« Reply #733 on: July 24, 2019, 10:19:29 AM »
@binntho
Don't know if this helps but:
I think the key difference between earlier BOEs and the approaching one, is that we are now at 415 ppm CO2.
Right now the ice really is a strong brake on the speed of change to a >415ppm equilibrium-state.
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binntho

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Re: When will the Arctic Go Ice Free?
« Reply #734 on: July 24, 2019, 10:39:21 AM »
@binntho
Don't know if this helps but:
I think the key difference between earlier BOEs and the approaching one, is that we are now at 415 ppm CO2.
Right now the ice really is a strong brake on the speed of change to a >415ppm equilibrium-state.
Well, so you say, but I don't think you are right. I do not think that without the ice we would rush toward an equilibrium state. Such a change (if it happens) will take a hell of a lot longer.

There have been long periods (million of years) in the past when CO2 was a lot higher than 415 without an equitable climate (there have even been ice ages with CO2 in the 1000s) so I don't see that one follows the other.
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Re: When will the Arctic Go Ice Free?
« Reply #735 on: July 24, 2019, 10:54:30 AM »
<snippage>
There have been long periods (million of years) in the past when CO2 was a lot higher than 415 without an equitable climate (there have even been ice ages with CO2 in the 1000s) so I don't see that one follows the other.
Did those periods, any earlier period, had such a large energy imbalance as we have now? Such a large forcing in W/m2? Our anthropocene climate had no time to change gradually with the extreme speed of our fossil CO2 pumping. Don't you think that's a significant difference?
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binntho

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Re: When will the Arctic Go Ice Free?
« Reply #736 on: July 24, 2019, 11:01:27 AM »
<snippage>
There have been long periods (million of years) in the past when CO2 was a lot higher than 415 without an equitable climate (there have even been ice ages with CO2 in the 1000s) so I don't see that one follows the other.
Did those periods, any earlier period, had such a large energy imbalance as we have now? Such a large forcing in W/m2? Our anthropocene climate had no time to change gradually with the extreme speed of our fossil CO2 pumping. Don't you think that's a significant difference?
Well I'm not sure what you mean about energy imbalance. But of course the huge speed of change now is very significant, and extremely dangerous.

But that does not mean that an eventual BOE will cause a calamitous catastrophe in and off it self (or an equitable climate in 11 years or whatever).

We are already facing a huge danger in ongoing AGW, some people seem to want to focus on an imaginary Harmageddon instead of facing the ongoing reality.
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be cause

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Re: When will the Arctic Go Ice Free?
« Reply #737 on: July 24, 2019, 12:00:29 PM »
.. and the ongoing reality isn't a harmageddon ? ?   b.c.
2007 + 5 = 2012 + 4 = 2016 + 3 = 2019 ...

binntho

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Re: When will the Arctic Go Ice Free?
« Reply #738 on: July 24, 2019, 01:10:38 PM »
.. and the ongoing reality isn't a harmageddon ? ?   b.c.
Definitely a potential Harmageddon, but not quite there yet.
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Re: When will the Arctic Go Ice Free?
« Reply #739 on: July 24, 2019, 01:42:01 PM »
Crandles I’m working on reply to your papers, I’ll hit you this afternoon, hopefully.

I just wanted to point out how terribly naive and unscientific Binnthos argument is.

1. Rate of change. The ice fee Arctic events he mentioned happened over millennia, not decades. RATE OF CHANGE

2. The only evidence he presents for “no cataclysm” is the fact that we are here. By that standard an asteroid like the one that killed the dinosaurs will not be cataclysmic

3.  He says that because nomadic, hunter gatherer  humans survived past climate change, no climatic cataclysm happened. He says so with confidence. Please think about it for one second.
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Re: When will the Arctic Go Ice Free?
« Reply #740 on: July 24, 2019, 02:33:45 PM »
He also says: We are already facing a huge danger in ongoing AGW
So his point is more that BOE as arbitrary point will not matter that much.

It´s bit like those socialist volunteers in Spain in the civil war. Be a slightly different version of the ism and you have a casus belli...and then the infighting always goes first before fighting the actual enemy.

Interested in those recent BOEs.

Rate of change....that one is important but also for the oceans (milankovich forcing has a local effect while we are now doing a global one)...and all the permafrost and oh well everywhere. So actually the Arctic is only a small if critical part of it.
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Re: When will the Arctic Go Ice Free?
« Reply #741 on: July 24, 2019, 02:35:00 PM »
   I wrote:
Quote
I sited a number of scientists who straight out said that a (near) ice free Arctic would be a very big deal with many dramatic consequences. Do you just flat out disagree with all of those scientists?

b wrote:
Quote
Well, you had links to a couple of articles on Downtoearth.com - is that what you mean? Those articles do not support that a BOE will have cataclysmic effects, so I sort of ignored them as having been a mistake on your part.

The articles, including the one from Scientific American, were full of quotes from major climate scientists and writers. You clearly just want to ignore them and all data that contradicts your pet theories. So this does not seem like a very worthwhile discussion to pursue further. Have a good day.
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Re: When will the Arctic Go Ice Free?
« Reply #742 on: July 24, 2019, 02:37:03 PM »
Let's return to the central issues...

1) When the Arctic will go ice free
2) How that is likely to play out from first ice free day, to week, to month, to season, to year
3) What the consequences are of that, and hence why we should care

1) ...The most likely correct projection is the limiting projection based on the full suite of projections, not the average, not the last, but the first. And that is based on volume. ...

That said, the outer bounds of the error band on projecting forward on ice volume suggest that we have already entered the outermost likelihood for an ice free summer day. Clearly this year won't be it. Next year could be. But most likely that won't be for a few years.

On the other end, the high band, we almost certainly will see it before 2030 even under the most unlikely combination of events. As a result, the first ice free day in September will almost certainly occur between 2022 and 2028.

We have different views and that is fine.

I can't completely rule out next year but I would tend to suggest maybe 50% or more chance of after 2030. Using linear PIOMAS volume trends for April and loss to Sept meet about 2033 but using such linear volume trends, it could well be before that due to variations from trend, using daily numbers, using CAB rather than all.

Volume does seem a more physical variable than area or extent, being grounded by latent heat of melting for a meaningful quantity of energy needed. So it seems a more logical choice.

If volume remains linear then extent has to accelerate downwards to meet the same timetable for ice free. With no other information this would appear a sensible logical choice to choose the volume trend over extent or area. However, we have lots of models practically all showing a deceleration in extent. Given this it is really likely that volume will have to decelerate even more to match the same timetable as following the extent curve.

So while volume trend seems a logical sensible selection, there is good reason to expect volume trend will not be linear and will decelerate.


Quote
2) ... The trend will remain for longer and longer ice free periods.

Longer and longer but at an ever slower rate is the impression I get from the trend in this graph from one of the papers you used as reference. (Yes the rapid drop is concerning. This is prior to BOE so it is not relevant as consequence of BOE but is concerning. Concerning, yes, cataclysm level, sorry not even close.)



as I said before "continuing very small amounts of Sept sea ice extents for 50 years after we get down to 1m km^2 does not seem to back up what is being suggested."

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Re: When will the Arctic Go Ice Free?
« Reply #743 on: July 24, 2019, 02:41:00 PM »
Crandles I’m working on reply to your papers, I’ll hit you this afternoon, hopefully.

I just wanted to point out how terribly naive and unscientific Binnthos argument is.

1. Rate of change. The ice fee Arctic events he mentioned happened over millennia, not decades. RATE OF CHANGE

2. The only evidence he presents for “no cataclysm” is the fact that we are here. By that standard an asteroid like the one that killed the dinosaurs will not be cataclysmic

3.  He says that because nomadic, hunter gatherer  humans survived past climate change, no climatic cataclysm happened. He says so with confidence. Please think about it for one second.

I posted the words below on the consequences thread. The only way an ice-free Arctic will not cause a climate catastrophe for life on earth is if that catastrophe happens before the Arctic goes ice-free. We could as well poison everything and destroy all the habitable places by other means instead?

A race to the bottom indeed.
_______________________________________________________________
Climate change is happening too fast...

https://www.theguardian.com/environment/2019/jul/23/animals-failing-to-adapt-to-speed-of-climate-crisis-study-finds
Animals failing to adapt to speed of climate crisis, study finds
Scientists warn of ‘alarming’ lag between human-driven seasons shift and animals’ behavioural changes

Quote
The speed of climate disruption is outstripping many animals’ capacity to adapt, according to a study that warns of a growing threat to even common species such as sparrows, magpies and deer.

Scientists behind the research described the results as alarming because they showed a dangerous lag between a human-driven shift in the seasons and behavioural changes in the natural world.

Previous academic work has shown that species respond to warming temperatures by earlier timing of biological events, for example egg-laying by birds, budding of plants and flying of insects. The new metastudy, published in Nature Research, examines how effective this is in terms of reproduction and survival.

Based on 10,090 abstracts and extracted data from 71 published studies, it found a clear lag in the majority of species studied and none could be considered safe. “The probability that none of the study species is at risk is virtually zero,” the paper notes.

The authors said hundreds of thousands of species were not covered by their study, which was weighted heavily towards birds in the northern hemisphere, but they said the problems of adaptation to climate change were likely to be even greater for other animals already deemed at risk of extinction.

Viktoriia Radchuk of the Leibniz Institute for Zoo and Wildlife Research in Germany, said: “Personally I find the results alarming. Species attempt to adapt to changing environment, but they cannot do it at a sufficient pace to ensure that populations are viable. Climate change has caused irreversible damage to our biodiversity already, as evidenced by the findings of this study. The fact that species struggle to adapt to the current rate of climate change means we have to take action immediately in order to at least halt or decrease the rate.”
[/quote]
« Last Edit: July 24, 2019, 03:34:30 PM by gerontocrat »
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Re: When will the Arctic Go Ice Free?
« Reply #744 on: July 24, 2019, 03:05:54 PM »
I think that we could avoid a lot of unnecessary disputes over something many "somehow" agree, if we would invent (ADD) an additional term to our vocabulary:

We are now talking about "Blue Ocean Events" = BOE

I suggest to add the term "Seasonal Blue Ocean State" = either BOS or SBOS

what do other think about that, as mentioned i think by distinguishing single BOEs and
a general new state that will repeat each or almost each summer, many heated debates
could be avoided and at the same time we would be more precise for "noobs" about what is meant.

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Re: When will the Arctic Go Ice Free?
« Reply #745 on: July 24, 2019, 03:13:33 PM »

Climate change is happening too fast...

https://www.theguardian.com/environment/2019/jul/23/animals-failing-to-adapt-to-speed-of-climate-crisis-study-finds
Animals failing to adapt to speed of climate crisis, study finds


Absolutely, so is this AGW related or BOE related? I suggest it is AGW related and therefore we should concentrate our efforts on reducing emissions causing AGW. BOE is a sideshow of at best debatable limited impact relative to AGW.

If there are lot of arguments about severity of BOE with the science possibly saying maybe not much effect, is it a sound argument for action on AGW? It is not an argument against action on AGW, but it is a weak argument for more action on AGW. Therefore we should concentrate on firmer argument for more action on AGW. Sea level rise, ocean acidification, species extinction and others are much better arguments for action on AGW and we should concentrate on those rather than on debating dodgy BOE effects arguments.

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Re: When will the Arctic Go Ice Free?
« Reply #746 on: July 24, 2019, 03:18:19 PM »
BOE is a sideshow of at best debatable limited impact relative to AGW.

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Re: When will the Arctic Go Ice Free?
« Reply #747 on: July 24, 2019, 04:29:27 PM »
@binntho
Don't know if this helps but:
I think the key difference between earlier BOEs and the approaching one, is that we are now at 415 ppm CO2.
Right now the ice really is a strong brake on the speed of change to a >415ppm equilibrium-state.

I agree and the fact we are warming faster than at any other time in the past 4 million years is relevant. Once we remove the brake the Arctic ice is behaving as, (we are already letting off our foot some) the very elevated CO2 levels will drive temperatures up much faster than in an interglacial maximum where the CO2 levels were 280 ppm. We are currently engaged in a colossal experiment with the earth's climate and past behavior is a poor predictor of what will happen.

Recent behavior of the climate and cutting edge research by climate scientists is a far better indication of what is in store. Having said this, I still believe reaching the arbitrarily set milestone of 1 million km2 of ice will appear as simply a continuum of what precedes this.

Ken Feldman

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Re: When will the Arctic Go Ice Free?
« Reply #748 on: July 24, 2019, 05:51:26 PM »
The reduction of 45% by 2030 and carbon neutral by 2050 is to keep warming under 1.5C.  I agree that probably wont happen.

Here's what the IPCC stated about reductions needed to stay under 2C:

Quote
In model pathways with no or limited overshoot of 1.5°C, global net anthropogenic CO2 emissions decline by about 45% from 2010 levels by 2030 (40–60% interquartile range), reaching net zero around 2050 (2045–2055 interquartile range). For limiting global warming to below 2°C11 CO2 emissions are projected to decline by about 25% by 2030 in most pathways (10–30% interquartile range) and reach net zero around 2070 (2065–2080 interquartile range). Non-CO2 emissions in pathways that limit global warming to 1.5°C show deep reductions that are similar to those in pathways limiting warming to 2°C. (high confidence) (Figure SPM.3a) {2.1, 2.3, Table 2.4}


Ken...you challenged someone for not reading the IPCC report that you linked to. Did you even read the quote you pulled from the report before you posted this comment? The bold underlined text has been highlighted by me.

Also please take a look at this linked chart...

https://ourworldindata.org/grapher/annual-co-emissions-by-region

...and explain to me where you think we will get a 11 billion ton reduction in annual CO2 emissions in the next decade in order to keep warming below 2C, given the current trends.

At best, emissions in 2030 will match emissions in 2019 and that is only if we start doing things we are not yet doing. We are not going to hold temp gains below 2C, not even close.

I noted the difference between 1.5C, which will be difficult to reach, and 2C, which is achievable.

As to reducing emissions by 11 billion tons annually by 2030, eliminating coal power plants will do that.

https://www.climatecentral.org/news/coal-plants-lock-in-300-billion-tons-of-co2-emissions-17950

Quote
Worldwide, coal-burning released 14.4 billion tons of CO2 in 2011.

With the cost of building new renewables (solar and wind) now much cheaper than operating coal power plants, there's an economic incentive to shut down coal power plants and replace them with wind and solar.  Utility companies in the US are already accelerating their retirements of coal power plants and replacing them with solar and wind.  The trend will accelerate as the cost of renewables is continuing to drop.

Renewables plus batteries are already replacing gas peaker power plants.  California recently cancelled two new gas peaker plants and is building solar farms with battery storage instead.

Even developing countries are cancelling planned coal power plants and building wind or solar instead.  Look at new developments in Kenya, Indonesia and Vietnam as examples.

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Re: When will the Arctic Go Ice Free?
« Reply #749 on: July 24, 2019, 06:10:05 PM »
Here's a link to a review article (an article that examines recent studies and summarizes them) published in the journal "Climate Change Reports" in December 2018. The article examines whether an ice-free Arctic leads to "tipping point" behavior and concludes that it doesn't.

https://link.springer.com/article/10.1007/s40641-018-0113-2

Quote
The Trajectory Towards a Seasonally Ice-Free Arctic Ocean

Dirk Notz, Julienne Stroeve

Abstract


Purpose of Review

The observed substantial loss of Arctic sea ice has raised prospects of a seasonally ice-free Arctic Ocean within the foreseeable future. In this review, we summarize our current understanding of the most likely trajectory of the Arctic sea-ice cover towards this state.


Recent Findings

The future trajectory of the Arctic sea-ice cover can be described through a deterministic component arising primarily from future greenhouse gas emissions, and a chaotic component arising from internal variability. The deterministic component is expected to cause a largely ice-free Arctic Ocean during summer for less than 2 ∘C global warming relative to pre-industrial levels. To keep chances below 5 % that the Arctic Ocean will largely be ice free in a given year, total future CO2 emissions must remain below 500 Gt.


Summary

The Arctic Ocean will become ice free during summer before mid-century unless greenhouse gas emissions are rapidly reduced.

Quote
The Impact of Self-Amplification


In addition to changes in the external forcing and internal variability, also a possible self-amplification of the ice loss has been suggested to contribute to the substantial ice loss in recent years. This has often been framed in the context of nonlinear threshold behavior of the ice cover, also referred to as “tipping points.” The main mechanism that has been suggested to possibly give rise to such “tipping” of the ice cover has been the ice-albedo feedback.


Past Evolution of the Sea-Ice Cover

The observed evolution of the Arctic sea-ice cover is inconsistent with the possible existence of a tipping point arising from self-amplification of the ice cover. First, the evolution has remained linearly linked to the long-term rise in global-mean temperature as outlined above. Second, the 1-year lag autocorrelation of year-to-year changes in summer sea-ice coverage is negative (around − 0.5, see also [26]), implying that after a summer with a particularly strong ice loss, the ice cover usually recovers somewhat in the following year. If indeed self-amplification played a significant role in the observed evolution of the ice cover, one would expect both an increasing failure of the linear relationship with rising temperature and an even more substantial ice loss after a year with a substantial ice loss.

Several stabilizing feedbacks during winter contribute to the lack of self-amplification even in light of the ice-albedo feedback [53]: First, any ice-free parts of the Arctic Ocean more effectively lose their heat to the atmosphere than those parts that remained ice-covered during winter [54]. Second, thin ice grows much faster than thick ice in response to the same external forcing, allowing for some recovery of total sea-ice volume after any record ice loss during summer [55]. And third, the later the ice cover forms, the thinner will be its isolating snow cover during winter [56].

Note that all these stabilizing feedbacks are only active during winter. Throughout summer of a given year, any small perturbation of the ice cover will be effectively amplified. For example, the observed progressively earlier melt onset translates directly to more absorption of solar heat, and thus to a more substantial ice loss during summer and a later onset of autumn freeze-up. This behavior has been found in the observational record [57] and can be used to estimate the timing of freeze onset at the end of the summer [58].

The observed lack of self-amplification of the ongoing ice loss is consistent with the behaviour of the Arctic sea-ice cover in large-scale climate models. In contrast, simplified models of the sea-ice cover often show instabilities [59]. This behavior has been explained by the lack of meridional heat transport and a lack of a seasonal cycle in these simplified models [60].