Complete Arctic Ice Melt

[Midnight Sun]

I’ve been following the Arctic Ice thread with interest, seeing the progress over time of the winter freeze and summer melt.

My question is, what would be the effects if the Arctic ice-cap were to completely melt one summer?

Would there be any increase in global sea-level? I guess not, because the melted ice just replaces the volume it’s currently displacing in the sea?

Would there be any change to water or air currents? Again I wouldn't have thought much, because the current ice-cap isn't a landmass, it doesn't affect deep water currents.

What other effects would there be?

[BrickFielder]

I have a suspicion the ocean conveyor belt would change in the north atlantic, due to a lack of ice cold water for deep water formation. The answer then becomes somewhat unpredictable with two potential outcomes, Either it remains clear or the lack of warm water transport into the arctic basin completely reverses the process.

[johnholmes]

ref the Arctic Ice

IF you meant to include the Greenland ice then that would have very serious consequences.

That said even when, if, we reach the point at which all ice melts in that area it will not be a sudden event but over many years I would suggest.

[Roger J Smith]

I think the question refers to the current speculation that we could be seeing summers without sea ice around the north polar regions, as early as 2013 as the story goes. I think that's faster than the current trends could support, but whatever the date, if it happens, this is my estimate of what it would mean.

First of all, it is difficult to separate cause and effect. Since warmer atmospheric and possibly oceanic temperatures would cause the loss of summer sea ice in the first instance, it is difficult to say that further similar weather patterns are being "caused" by the open water, since they would be possible in the year or two before that happened.

But the change from sea ice to open water would certainly have expected results on regional climates. It would imply a stronger storm track at higher latitudes, and some cases of low pressure racing past the north pole in erratic fashion as longitude contracts to almost zero in the very far north.

My guess is that a period of open summer polar sea conditions would rather quickly lead to an expansion of land ice around the arctic basin. While global warming proponents might expect to see ongoing warmth and melting, I would expect the cause to be largely natural, and in the past, natural cycles of glaciation have been preceded by open water at higher latitudes. This is because the late summer and autumn are then ideal seasons for snow to be deposited before a deep freeze sets in north of the arctic circle. This was in fact already previewed by what I was calling the "rebound" effect from extensive melting in 2007, to the harsh Eurasian and North American winter of 2007-08 (in many regions, at least, a lot of additional snowfall in particular).

The effect on ocean currents would probably be to invigorate them in all cases, based more on historical analogues than any modelling assumptions.

It's all very uncertain and may well not happen at all, especially soon.

[Midnight Sun]

Thanks everyone for your replies.

There is an awful lot to consider!

It would be interesting to see the different theories of the various feedbacks/effects discussed in the Arctic Ice thread, which for a novice like me just seems to consist of "bad news, it's melting faster" comments. To which my reply is "but why does that matter?" - and now I know! Thanks again.

[Gray-Wolf]

Seeing as we haven't 'witnessed' such an event in our technological era we can all only speculate and then you are left to use your 'common' to figure which view is most reasonable.

For me I see a global tipping point slowly tipping.

The loss of summer ice cover has implications for the whole planet which will include other 'tipping points' being breached.

I do not buy the 'issues' for the NAD/Gulf stream as the outflow from the Greenland melt (plus the loss of the perennial into the N.Atlantic) would appear to have re-invigorated the descending columns of cold water which form the northern end of the current. I can , however, see the extension of the current into the Arctic and even the exchange of Pacific/Atlantic waters in the high arctic. Any current to amplify the Arctic Gyre is bad news (to me) as it merely aids the 'flush out' of winter ice into more temperate latitudes to ablate.

Recent measures suggest the loss of sea ice impacts ground temps up to 1800km in land. This has serious implications for the perma-frost and the greenhouse gasses it holds. Recent increases of methane concentrations in high latitudes is being investigated currently but if we see 09' bringing a higher 'spike' I know where I would guess it comes from.

I am a great believer in the 'butterfly's wing' theory of interconnectedness of weather/climate. I know we have debates about the difference between those two but alter weather patterns for long enough and you have a new climate.......I'm sure I'll be put right if this is not the case.Open large areas of sea and you get new areas of evaporation and new areas for heat storage. Both these things impact on local weather and push climate into new patterns. We cannot have an Arctic amplification without it impacting on the climate systems operating around it.As with all change it starts off slowly and gains momentum until it is in free fall (I like to use a collapsing dam as an analogy, micro fissures first ,then cracks ,then catastrophic failure).

[MR EXTREMES]

gray wolf the most likely would be ocean conveyor shutdown cooler climate alot cooler.

if not then as was said stronger storms warmer sea temps and if it where to warm for hundreds of years then sea temps would rise when it reaches 26c 27c then hurricaines will start to form in the north alantic and lots and lots of evaporation making lots and lots of rain most likely.

but droughts have been around for millions of years and still are now,

and i think we do not have enough evidence in christmas pudding to be calulating the distruction of the earth nobody really knows there just theorys idears thats all.

the only evidence we have got is there have been major droughts before major freezes ect ect.

[Gray-Wolf]

I would say the planet is pretty efficient at keeping things within operating parameters for any given global temp. When things occur to 'alter' the parameters change cascades through the climate system until the next 'stable' set of parameters are reached. The carbon cycle is part of this and ,on occasion, 'lost' carbon (stored in the lower crust) is accessed by volcanism and we have 'natural' additional carbon added back into the climate system. We have been accessing this 'deep stored carbon' and introducing it back into a 'stable' climate system. We cannot expect a benign result to this tinkering. We have altered vast tracks of the planets regulating system by deforestation at the same time.We have altered the too much for there to be no noticeable changes.

AGW has always been mooted to arrive in the polar regions first and primarily the northern cryosphere (it being mainly at sea level) first. Why so many have problems at witnessing something so widely predicted (apart from a natural terror of the consequences) I do not know.

[jethro]

I would say the planet is pretty efficient at keeping things within operating parameters for any given global temp. When things occur to 'alter' the parameters change cascades through the climate system until the next 'stable' set of parameters are reached. The carbon cycle is part of this and ,on occasion, 'lost' carbon (stored in the lower crust) is accessed by volcanism and we have 'natural' additional carbon added back into the climate system. We have been accessing this 'deep stored carbon' and introducing it back into a 'stable' climate system. We cannot expect a benign result to this tinkering. We have altered vast tracks of the planets regulating system by deforestation at the same time.We have altered the too much for there to be no noticeable changes.

AGW has always been mooted to arrive in the polar regions first and primarily the northern cryosphere (it being mainly at sea level) first. Why so many have problems at witnessing something so widely predicted (apart from a natural terror of the consequences) I do not know.

Action and reaction, that's how everything in life works. Historically, the reaction to an ice free Arctic has been a cool down; there is nothing to suggest a different reaction this time around should we end up loosing summer ice.

Your basis for catastrophe or a different outcome than previously experienced is purely a belief system that mankind's tinkering will lead to Mother Nature wreaking revenge. Again, an hypothesis dependant upon the Earth being a sentient being. It is not.

At the very most, if (and that's a big if) we have, or can impact the climate systems to such a degree that we can trigger a tipping point, the reaction to such will be the same as it has always been. There will be no creation of unique feedbacks, just possibly hastening their reaction.

Don't forget, the entire Arctic could melt and apart from a teeny rise in sea levels due to thermal expansion, it would have no impact upon sea level at all. It would require the Greenland ice cap to melt (which it isn't, it is in places but gaining ice in others, so no net impact) ditto Antarctica, the peninsula is breaking up, the land based interior isn't. And no, the girdle holding it all in place doesn't make sense either when it comes to land based ice.

[pottyprof]

Okay. I have edited and removed some posts to keep this thread on topic.

Discussion on Climate Change can be found here

Ta muchly..

[stewfox]

What other effects would there be?

I would be interested in peoples comments on things like tourism and the like

Whats everyone with say £5,000 to spend ,going to want to do , get on ship and go to 90N

The impact on surrounding land based wild life fauna etc I would assume would be huge

International 'borders' , imagine the number of cruise ships etc Political implications etc

I think that would have more impact then a 3mm sea rise

[Gray-Wolf]

I

I think that would have more impact then a 3mm sea rise

I cannot see why people only focus upon the region beyond 75N.

If we loose the ice we loose our global thermostat......

This would entail the melting of sections of Greenland along with impacts on both E. and W. AIS.

This would upset the normal global circulation patterns of the oceans.

These would have impacts on global weather patterns.

How many would be impacted if we lost the Asian Monsoon season???

How would the planet cope if we lost Amazonia? (or had it turn from a carbon sink into a producer??)

What of the permafrosts and their stored carbon??

What of Sub-Saharan Africa?

What of the salt panning of the mid- west USA if more irrigation is required to keep the 'grain basket of the world' in operation??

This is neither trivial nor insignificant. 6.6 billion folk and rising remember. No one can afford to think "I'm alright Jack" as every individual will be impacted.

What of the flora and fauna of the planet? can we accept our role in their demise or do we hide behind 'natural cycles' or 'it's all happened before' (not!!)???

[Methuselah]

I doubt that the deniers really care about it, GW; it's in their collective interest to bury their heads in the sand...What problems???

[valiant]

This is neither trivial nor insignificant. 6.6 billion folk and rising remember. No one can afford to think "I'm alright Jack" as every individual will be impacted.

And that's what it's all about. Not WHAT we are doing ... but that there are 6.6 billion people doing it.

[jethro]

I doubt that the deniers really care about it, GW; it's in their collective interest to bury their heads in the sand...What problems???

Ahem, the need for this was?

I take it you agree with GW's proposals of impact then? Would either of you care to post peer reviewed science to substantiate that comprehensive list of impacts we can expect from losing Arctic ice?

[Gray-Wolf]

I doubt that the deniers really care about it, GW; it's in their collective interest to bury their heads in the sand...What problems???

Though a little off topic I do tend to agree Pete though with reservations.

Some folk, who are as capable of assessing things as well as you or I, still tend prefer to go rummaging for alternative scenarios that might ,just might, be culpable for the impacts we are witnessing (and save us from the global changes we can foresee occurring over the next 30 or so years).

I belive neither of us relish the position we see the planet in nor wish it's continuation but what can we do? We may salve our individual consciences but can we alter the immediate fate for the planet? I ,sadly ,doubt that we can.

From the first times we ever spoke on line I have been of the opinion that many 'deniers' are working through some kind of grief process at the loss of the world we thought we knew. As we all know the first phase of this process is denial.

As 'humans' we are all culpable. As individuals it is hard to accept our individual role (across the lifespan lived) in the trashing of our planet.Many of the 'choices' we were given in this process were no choice at all. The raw materials for the goods were already ripped from the planet, the energy to change them into the goods was already spent we just gave into a twisted sense of 'need' and parted with our cash.

Maybe I'm stuck in the 'blame' phase of grieving but I see many individuals who did have the opportunity to make the planet different but followed up on their own personal greed for money and power instead.

When the Arctic Ocean is Ice free over the late summer months surely those in denial must move forward in their acceptance of humanities culpability in starting this set of changes even though the planet will have taken over the process by then with a plethora of feedback loops as ever more tipping points are breached.

Oh! Happy Days!

[Methuselah]

Ahem, the need for this was?

I take it you agree with GW's proposals of impact then? Would either of you care to post peer reviewed science to substantiate that comprehensive list of impacts we can expect from losing Arctic ice?

Sorry, Jethro - I don't class you as a 'denier' btw...

That said, the question is a hypothretical one so so are its answers? But IF all the Arctic ice (I include Greenland) were to melt there would have to be profound consequences: where would all the water go? What would happen to the ocean currents that depend on ice-melt? How would Europe's growing-season be influenced? And so on...

Having wittered on with all that, I don't think that any of this will happen very soon...

Though a little off topic I do tend to agree Pete though with reservations.

Some folk, who are as capable of assessing things as well as you or I, still tend prefer to go rummaging for alternative scenarios that might ,just might, be culpable for the impacts we are witnessing (and save us from the global changes we can foresee occurring over the next 30 or so years).

I belive neither of us relish the position we see the planet in nor wish it's continuation but what can we do? We may salve our individual consciences but can we alter the immediate fate for the planet? I ,sadly ,doubt that we can.

From the first times we ever spoke on line I have been of the opinion that many 'deniers' are working through some kind of grief process at the loss of the world we thought we knew. As we all know the first phase of this process is denial.

As 'humans' we are all culpable. As individuals it is hard to accept our individual role (across the lifespan lived) in the trashing of our planet.Many of the 'choices' we were given in this process were no choice at all. The raw materials for the goods were already ripped from the planet, the energy to change them into the goods was already spent we just gave into a twisted sense of 'need' and parted with our cash.

Maybe I'm stuck in the 'blame' phase of grieving but I see many individuals who did have the opportunity to make the planet different but followed up on their own personal greed for money and power instead.

When the Arctic Ocean is Ice free over the late summer months surely those in denial must move forward in their acceptance of humanities culpability in starting this set of changes even though the planet will have taken over the process by then with a plethora of feedback loops as ever more tipping points are breached.

Oh! Happy Days!

I share your reservations, Ian...I too am guilty!

[jethro]

Sorry, Jethro - I don't class you as a 'denier' btw...

That said, the question is a hypothretical one so so are its answers? But IF all the Arctic ice (I include Greenland) were to melt there would have to be profound consequences: where would all the water go? What would happen to the ocean currents that depend on ice-melt? How would Europe's growing-season be influenced? And so on...

Having wittered on with all that, I don't think that any of this will happen very soon...

I share your reservations, Ian...I too am guilty!

I don't class myself as a denier either, but I do find the term needless, inflammatory and insulting; when will everyone (if ever) move away from these pointless tags?

This thread is about the consequences of complete Arctic melt, not entire Northern hemisphere - Greenland is irrelevant.

The doom and gloom, aren't we all despicable nonsense is without foundation from a scientific point of view.

[Methuselah]

I don't class myself as a denier either, but I do find the term needless, inflammatory and insulting; when will everyone (if ever) move away from these pointless tags?

This thread is about the consequences of complete Arctic melt, not entire Northern hemisphere - Greenland is irrelevant.

The doom and gloom, aren't we all despicable nonsense is without foundation from a scientific point of view.

Hey Jeth, the term denier may sound inflammatory, but I've heard real deniers on the radio: the world's not getting warmer, there's no such thing as GW (anthropogenic or otherwise). They say these things Jethro, believe me. But, you are not one of them - I know that... The globe has warmed over the past century, of that there can be little doubt...Why, I don't prefess to know, but it has; and, why it has - well, I don't know that either.

Is Greenland irrelevant? Can one imagine the loss of ALL of the Arctic's ice whilst that on Greenland remains intact? I don't know, and I make no pretense...

Your last paragragh I agree with: of course, we are not all despicable - we are acting in the way that Natural Selection dictates: we take what we want when we want to take it...But, can we not move above that?

[jethro]

Hey Jeth, the term denier may sound inflammatory, but I've heard real deniers on the radio: the world's not getting warmer, there's no such thing as GW (anthropogenic or otherwise). They say these things Jethro, believe me. But, you are not one of them - I know that... The globe has warmed over the past century, of that there can be little doubt...Why, I don't prefess to know, but it has; and, why it has - well, I don't know that either.

Is Greenland irrelevant? Can one imagine the loss of ALL of the Arctic's ice whilst that on Greenland remains intact? I don't know, and I make no pretense...

Your last paragragh I agree with: of course, we are not all despicable - we are acting in the way that Natural Selection dictates: we take what we want when we want to take it...But, can we not move above that?

Sorry but I dislike the tags, they're banded around willy nilly and do nothing except cause controversy.

Of course it's possible to imagine an ice free Arctic whilst Greenland remains intact. We're talking summer ice loss, not perennial, year round loss - that's an impossible scenario whilst the Earth's tectonic plates remain in their current configuration. The vast majority of ice loss has been caused by warmer ocean currents, Greenland glaciers are land based.

[Methuselah]

Sorry but I dislike the tags, they're banded around willy nilly and do nothing except cause controversy.

Of course it's possible to imagine an ice free Arctic whilst Greenland remains intact. We're talking summer ice loss, not perennial, year round loss - that's an impossible scenario whilst the Earth's tectonic plates remain in their current configuration. The vast majority of ice loss has been caused by warmer ocean currents, Greenland glaciers are land based.

Okay, let's drop the 'deniers' tag???

But I say again: this whole discussion is based on an hypothesis??? I agree about the tectonic plates: so long as Antarctica remains separated by the circumpolar current, I can't see the globe's climate changing fundamentally for a long time...

I may believe in AGW, but I certainly do not believe that Armageddon is just around the corner!

Sorry for the split infinitive!