The Next Ice Age

[ribster]

Quite simply: the report you read was untrue.

Paul

Thats rather dismissive, gentlemen by the name of Professor Bryden and Dr. Cunningham of the National Oceanography Centre and their team would tend to disagree with you!

Edited June 4, 2006 by ribster

[Methuselah]

Thats rather dismissive, gentlemen by the name of Professor Bryden and Dr. Cunningham of the National Oceanography Centre and their team would tend to disagree with you!

But surely, if the Atlantic Conveyor has indeed slowed by 30% in ten years', wouldn't the sea areas around Iceland/Greenland/The Arctic be anomolously cold AND still be getting colder??? Where is the heat that's melting the sea-ice coming from - if not from the AC?

If science is supposed to explain what we observe, how does a 30% reduction in heat being transported northwards by the AC explain the observed temperature increase at high latitudes??

The way I perceive it is: i) the Arctic regions are getting warmer. Ergo, ii) There's more heat getting there than there was before. Ergo, iii) As the major mechanism of northwards heat-transport, the Atlantic Conveyor cannot be transporting 30% less heat??

[Essan]

The findings, published in the journal Nature, found that the Atlantic Conveyor flow slowed by about 30 percent between 1957 and 2004.

http://www.cnn.com/2005/TECH/science/11/30...tudy/index.html

Edited June 5, 2006 by Essan

[West is Best]

Thats rather dismissive, gentlemen by the name of Professor Bryden and Dr. Cunningham of the National Oceanography Centre and their team would tend to disagree with you!

I think the point was that the report has been called into question. My understanding is that the data sample size has been called into question, as well as its reliability, and gathered on such an ad hoc basis that the general scientific consensus seems to be 'unproven'. Much more solid work needs to be done.

[ribster]

I think the point was that the report has been called into question. My understanding is that the data sample size has been called into question, as well as its reliability, and gathered on such an ad hoc basis that the general scientific consensus seems to be 'unproven'. Much more solid work needs to be done.

Fair play WIB, thats at least better than dismissing something out of hand, especially if it doesn't fit in with that persons beliefs. Claim and counter-claim can be made for much that it is going on with the worlds climate.

[John Cox]

Hi all, not sure that its the right place for this, but I was reading a report recently that says the atlantic conveyor has slowed down by 30% over the last 10 years, and the trend is set to continue. Over the next 10 years our average temperature being reduced by 1 degrees. The suggestion being that as the trend continues our climate will actually get cooler.

Just wondered what anyone thinks or knows about that?

Cheers, rib.

Hi Ribster.

Well last winter certainly bucked the trend of the last 5 winters and it was certainly coldest winter here in Dublin since 2001.

[BrickFielder]

Well I assume that you are referring to this work.

Could the Atlantic Current Switch Off

RapidMOC

When looking at heat flows and salinity and we must take into account the Atlantic Multidecal oscillations which show that large changes in heat flux and salinity are not uncommon over the kinds of periods mentioned here.

Role of the Ocean Conveyor Belt

Isolating natural changes from man made changes is a bit difficult and understanding what exactly is being claimed is a bit difficult. Delving into the actual data shows some discrepancies with what is being claimed.

For instance on the florida side I don't see much of a change in the gulf stream.

Florida Current Transport

Gulf Stream

From numerous different sources it is obvious that the northern atlantic circulation is changing although I am unsure as to whether this is wholly due to natural cycles or a combination of natural cycles and climate change. Certainly the changes are worrying , but also the changes are taken out of context and with a view to further funding of the project. By far the most convincing evidence of changes I think comes from fishermen who fish these waters and are having to move their traditional fishing areas.

[ribster]

Hi Ribster.

Well last winter certainly bucked the trend of the last 5 winters and it was certainly coldest winter here in Dublin since 2001.

Hi John, indeed, I rather enjoyed winter this year and it certainly broke the trend of late. I am looking forward to a run of better winters, and wouldnt shed a tear if our climate turned slightly cooler!

Cheers, rib.

Well I assume that you are referring to this work.

Could the Atlantic Current Switch Off

RapidMOC

When looking at heat flows and salinity and we must take into account the Atlantic Multidecal oscillations which show that large changes in heat flux and salinity are not uncommon over the kinds of periods mentioned here.

Role of the Ocean Conveyor Belt

Isolating natural changes from man made changes is a bit difficult and understanding what exactly is being claimed is a bit difficult. Delving into the actual data shows some discrepancies with what is being claimed.

For instance on the florida side I don't see much of a change in the gulf stream.

Florida Current Transport

Gulf Stream

From numerous different sources it is obvious that the northern atlantic circulation is changing although I am unsure as to whether this is wholly due to natural cycles or a combination of natural cycles and climate change. Certainly the changes are worrying , but also the changes are taken out of context and with a view to further funding of the project. By far the most convincing evidence of changes I think comes from fishermen who fish these waters and are having to move their traditional fishing areas.

Yeah that's some of the stuff I've been looking at. I wasn't suggesting that what is claimed is set in concrete, or that it cannot be challenged as is the case with much scientific or academic work, especially in relation to climate change.

Just thought it was interesting and something worth thinking about.

Cheers, rib.

Edited June 6, 2006 by ribster

[Dawlish]

Thats rather dismissive, gentlemen by the name of Professor Bryden and Dr. Cunningham of the National Oceanography Centre and their team would tend to disagree with you!

It isn't dismissive at all, ribster, neither is it meant to be. The report that Kippure read was untrue, if he is quoting verbatim from it. Prof Bryden and Dr, Cunningham would agree with me I'm sure.

If you actually read their research, via their excellent article in Nature, you'll find that they did not say that the Gulf Stream, or the NAD, or any other Northward-moving current associated with warm water transport to our shores has decreased in strength.

What they did find was that one Southward moving current, which has not been properly measured for the last 5 years, had decreased by 30% from the last set of measurements.

I stand by my assertion that there is no direct evidence, as of now, that there has been any decrease in the flow of warm water towards our latitudes in the Atlantic. All you have to do to verify that is to read the Southampton Uni research.

There is an enormous misconception doing the rounds about the NAD. It has been perpetrated by some very poor understanding of the actual research by secondary newspaper reports and other people and it really is typical of how a small exaggeration, or a mis-read, even, can persuade an awful lot of people that the truth is something different from the reality. I would never dismiss good science and the Southampton Uni team performed good science. They also commented on the limitations of their own research and called for more.

Just read the article - it is pay site, is "Nature", so you will have to subscribe, or you may have to get a back copy from the local library, but to read it will be enlightening and will erase the misconception - promise!

Regards, Paul

Edited June 6, 2006 by Dawlish

[Dawlish]

Fair play WIB, thats at least better than dismissing something out of hand, especially if it doesn't fit in with that persons beliefs. Claim and counter-claim can be made for much that it is going on with the worlds climate.

Ah! Missed this one. A bit harsh, ribster; read the research and I'm sure you'll send me a tiny smiley as an apology!

Regards, Paul

[John Cox]

Well I assume that you are referring to this work.

Could the Atlantic Current Switch Off

Gulf Stream

From numerous different sources it is obvious that the northern atlantic circulation is changing although I am unsure as to whether this is wholly due to natural cycles or a combination of natural cycles and climate change. Certainly the changes are worrying , but also the changes are taken out of context and with a view to further funding of the project. By far the most convincing evidence of changes I think comes from fishermen who fish these waters and are having to move their traditional fishing areas.

Hi Brickfielder,

As usual a great post.

What all these reports show is that there are definate signs that the NAD is slowing.

The big question is: Is it slowing enough to change our climate.

I, for one, am happy to bide my time to watch and read more.

Watching.... The synoptics seem to be chaning. Temporary or permenant?. Time will tell.

I have an open mind in.(I hope).

I do love the cold and would love for colder winters. So maybe I read the reports that suit my needs.

However, there does seem to be more scientific report that Europe is likely to get colder rather than warmer in the years ahead. I have 35 URL's that go with this theory.

Does anyone have the same amount or similar (not a contest B) ) to show the other side of the coin?

Hi John, indeed, I rather enjoyed winter this year and it certainly broke the trend of late. I am looking forward to a run of better winters, and wouldnt shed a tear if our climate turned slightly cooler!

Cheers, rib.

Hi Ribster,

Yes, if this quiet atlantic continues for most of the Summer it will just consolidate the quiet atlantic change we had last winter with much cooler effects.

[Dawlish]

Hi Brickfielder,

As usual a great post.

What all these reports show is that there are definate signs that the NAD is slowing.

The big question is: Is it slowing enough to change our climate.

I, for one, am happy to bide my time to watch and read more.

Watching.... The synoptics seem to be chaning. Temporary or permenant?. Time will tell.

I have an open mind in.(I hope).

I do love the cold and would love for colder winters. So maybe I read the reports that suit my needs.

However, there does seem to be more scientific report that Europe is likely to get colder rather than warmer in the years ahead. I have 35 URL's that go with this theory.

Does anyone have the same amount or similar (not a contest B) ) to show the other side of the coin?

Hi Ribster,

Yes, if this quiet atlantic continues for most of the Summer it will just consolidate the quiet atlantic change we had last winter with much cooler effects.

John, I am sorry, but "these reports", which all stem from misunderstanding of the original Southampton Uni reasearch, do not show any signs of the NAD slowing. The evidence is not there and I'm going to have to ask those that believe that the NAD is slowing to provide the evidence, instead of simply repeating this false mantra that it is.

It is not. There hasn't been a single piece of research that has shown this. If there has; lead us to it, or come to a different conclusion based upon the evidence available. Superted's comments on the actual Arctic warming events, which do not correlate at all with the NAD slowing, must surely make you question your point of view. If they don't, then you really must read the research conclusions of the most recent studies. There is a suspicion that it may slow in the future and I can go along with that, the reasearch I've referred to and Prof Wadham's studies suggest this may happen, but they provide no evidence for it actually happening. As a result, I cannot accept that any reports have shown that it is presently declining in strength......because there haven't been any!!

I'd love to read them if I'm wrong; really I would.

"These reports"........do not exist!

Regards. Paul

Edited June 6, 2006 by Dawlish

[Guest Mike W]

I think your right Dawlish, becasue I think they said only that more fresh water is entering the NAD and this will lead to a slow down in the near future of the NAD, so your correct in that it hasn't slowed down yet, and obviously if had already then it would be getting cooler or colder in the last 5-8 years at least which it hasn't, so it case of waiting to see when it will slow down, or start to slow down as it were. I always thought that the NAD got messed up in the past due to things like high volcanic activity such as in the LIA and also low solar activity also causing a weaking in the NAD aswell, sort of like 2 key factors I would of thought, only becasue I would of thought it woyuld need some cooling set up in the first place and a nd interference.

[BrickFielder]

I don't think there is convincing evidence that a dramtic slow down of the Gulf stream is taking place I do however think that there are significant changes in the location of currents in the north Atlantic and that the north atlantic drift may be altering.

Peter Wadhams of Cambridge University

(Yes I know other research suggests the sinking gyres have moved but Peter still maintains major changes are taking place)

WHOI

Dilution of the northern North Atlantic in recent decades

[ribster]

It isn't dismissive at all, ribster, neither is it meant to be. The report that Kippure read was untrue, if he is quoting verbatim from it. Prof Bryden and Dr, Cunningham would agree with me I'm sure.

If you actually read their research, via their excellent article in Nature, you'll find that they did not say that the Gulf Stream, or the NAD, or any other Northward-moving current associated with warm water transport to our shores has decreased in strength.

What they did find was that one Southward moving current, which has not been properly measured for the last 5 years, had decreased by 30% from the last set of measurements.

I stand by my assertion that there is no direct evidence, as of now, that there has been any decrease in the flow of warm water towards our latitudes in the Atlantic. All you have to do to verify that is to read the Southampton Uni research.

There is an enormous misconception doing the rounds about the NAD. It has been perpetrated by some very poor understanding of the actual research by secondary newspaper reports and other people and it really is typical of how a small exaggeration, or a mis-read, even, can persuade an awful lot of people that the truth is something different from the reality. I would never dismiss good science and the Southampton Uni team performed good science. They also commented on the limitations of their own research and called for more.

Just read the article - it is pay site, is "Nature", so you will have to subscribe, or you may have to get a back copy from the local library, but to read it will be enlightening and will erase the misconception - promise!

Regards, Paul

Hi Paul, thats not the only research I've been reading, and your interpretation is different to mine. I'm not going to argue the point, as I am no expert but I can read. To be honest I find your style a little agressive. I'm a relative newbie and a little wet behind the ears, I hope your'e not as forceful with all newcomers, you'll be scaring them away!

No offence intended by the way, we shall just have to agree to disagree!

Edited June 7, 2006 by ribster

[John Cox]

Hi Paul, thats not the only research I've been reading, and your interpretation is different to mine. I'm not going to argue the point, as I am no expert but I can read. To be honest I find your style a little agressive. I'm a relative newbie and a little wet behind the ears, I hope your'e not as forceful with all newcomers, you'll be scaring them away!

No offence intended by the way, we shall just have to agree to disagree!

Hi Ribster,

Dont worry,

I am not a newbie but have to put up with very techical points being thrown at me.

Chin up, you would be surprised with the support you might have.

[wellington boot]

Look this needs to be cleared up - people are getting very confused. It is really quite simple. Dawlish is right in that the research does not suggest that the Gulf Stream bringing heat north has yet slowed down.

However, research does show that because of increasing levels of fresh water being released from melting ice caps in the arctic, the current running south, which is the other half of the conveyor belt, HAS been shown to be significantly weaker than when last measured, by something like 6m tonnes of water per second. Fairly substantial. This has not yet caused any noticeable drop in temperature in europe as a result of less gulf stream heat, but it has been noticed that, of the water moving north towards europe, an increasing amount is branching off earlier than "it should". This, along with the weaker current running SOUTH, has given rise to concern that a continuation of the trend, because of glbal warming, could see the gulf stream shut down altogether, very suddenly. This is based on the belief that the gulf stream won't slow down gradually to a stop, but will at some point, when there is simply not enough energy going into the cycle, or there is too much fresh water in the arctic stopping the cold water from sinking, simply stop. It's all speculation to some extent anyway, but i hope this clears up some points

[ribster]

Hi Ribster,

Dont worry,

I am not a newbie but have to put up with very techical points being thrown at me.

Chin up, you would be surprised with the support you might have.

Hi John, thanks for that. I had vowed that I wouldn't come on during the warmer months, being a bit of a winter lover (as if you couldn't tell!). Some of the other forum members said at the time I wouldn't be able to stay away - I guess they were right!

[Snowly does it]

Look this needs to be cleared up - people are getting very confused. It is really quite simple. Dawlish is right in that the research does not suggest that the Gulf Stream bringing heat north has yet slowed down.

edit - etc

excellent concise and clear post!

From what I have read and seen, the whole shutdown issue will come down to simple mathematics. Fresh water being released = a given under a warming climate, potential of drift shutdown = increases with the amount of fresh water released. Therefore he warmer we get, the higher the chance of a shutdown. However it is important to remember that the last shutdown is assumed to have occured at a point of Ice Age - and there was by its very nature a far greater concentration of fresh water to be released under such conditions.

If there IS enough, then it becomes a qustion of when, what the conditions are Artic ways etc as to the effect it would have on places like the UK - but from an amateur standpoint I would suggest that reglaciation of the Scottish Mountain ranges, devastation of British Agriculture and Transport infrastructures and sea ice in the channel are all extremely probable, as would be rampant mortality in our poorly equipped modern housing (from a deep cold perspective)

[Gray-Wolf]

I thought that it was a well held 'truth' (esp. in light of yet another scientific paper on the subject) that more heat is transfered to the poles by air masses than by water. As such the stopping of a single transportation route of heat north wards is nowhere near enough to change (over time) our climate. The continued heating on the other hand is and the ablation of the permanent ice will lead to a rapid temp. increase over the mid latitudes as warm air 'stalls out ' over these regions.

[Dawlish]

Hi Paul, thats not the only research I've been reading, and your interpretation is different to mine. I'm not going to argue the point, as I am no expert but I can read. To be honest I find your style a little agressive. I'm a relative newbie and a little wet behind the ears, I hope your'e not as forceful with all newcomers, you'll be scaring them away!

No offence intended by the way, we shall just have to agree to disagree!

There is no need to "agree to disagree" at all. Lead us to the other reasearch you have been reading. I'd be interested. It is not "aggressive" (a strange word to describe debating) to ask for evidence to back up a position thatone feels is not correct. That is the basis of academic debate. I am as much a newbie as you are, on netweather; indeed we joined about the same time, by the looks of it, but I don't use that as a defence to back out of a discussion! I've found people on here very willing to discuss and debate. I hope you'll be one of them. John debates well and although it seems that I don't agree with his position, I still respect it. Join in and do the same!

Regards, Paul

PS Do I know you from somewhere?

Edited June 9, 2006 by Dawlish

[John Cox]

John debates well and although it seems that I don't agree with his position, I still respect it. Join in and do the same!

Regards, Paul

John me???

[Dawlish]

John me???

I think so! I hope ribster hasn't confused me! i think you put your point very well, though I don't agree with it!!

*>))

Wellington boot: thanks. Very true. Prof Wadham's research opens up the possibility of changes in the NAD, as does the Southampton Uni reasearch, but neither are in any way conclusive, as to a slowdown in the Gulf Stream - as both acknowledge, in the limitations of their findings, in the the coda of both their research articles. To see and understand this, you've really got to read them both in their entirity and there's no real excuse for not doing that, if you are going to quote them as evidence for the possible shutting down of the NAD. It really would change your thinking about this topic, if all you've done is read poorly researched, and headlined, newspaper articles about the ecxcellent, original, research.

Snowmaiden: Brickfielder's summary is spot on. There are no "simple mathematics" in this process. The South to North element of the energy flows in the NAD/Gulf stream/NAC is fuelled by the thermohaline circulation, only to a certain degree. It is thought (though perhaps not proven) that winds have more influence on the N toS energy flows, that the water element.

It is so easy to think that a slowing of the sinking, cold, fresh water in the arctic will contribute to a shutting down of the NAD, but in fact, the wind-driven element, may be enough to compensate for much of the slowdown, even if it was occurring (of which there is no evidence whatsoever to say that it is!)

Paul

PS Excellent debate!

[Snowly does it]

Snowmaiden: Brickfielder's summary is spot on. There are no "simple mathematics" in this process. The South to North element of the energy flows in the NAD/Gulf stream/NAC is fuelled by the thermohaline circulation, only to a certain degree. It is thought (though perhaps not proven) that winds have more influence on the N toS energy flows, that the water element.

Fair enough and I'll admit to a lack of in depth knowledge here, but let's imagine for a moment that the water borne element of the Drift did indeed shut down.. I ask this following question as one without a clue of what the answer would be btw!.. would that have an effect on the wind influence.. I.E would the wind borne heating element veer more southerly without the drift's water flow to track along?

Someone with the geological nouse to fill me in on the correlation will have my eternal gratitude!

Edited June 10, 2006 by snowmaiden

[ribster]

There is no need to "agree to disagree" at all. Lead us to the other reasearch you have been reading. I'd be interested. It is not "aggressive" (a strange word to describe debating) to ask for evidence to back up a position thatone feels is not correct. That is the basis of academic debate. I am as much a newbie as you are, on netweather; indeed we joined about the same time, by the looks of it, but I don't use that as a defence to back out of a discussion! I've found people on here very willing to discuss and debate. I hope you'll be one of them. John debates well and although it seems that I don't agree with his position, I still respect it. Join in and do the same!

Regards, Paul

PS Do I know you from somewhere?

Fair enough, but I'm no scientist and certainly no meterologist. I read what I read as a layman and have no in depth knowledge of the subject. I see no point in regurgitating what I read, the original post was just to see what other people think on the subject, in order to gauge some opinion. Your initial response was simply to dismiss the research, without elaborating (which you have since done). Others came back with something more substantial and backed it up, which I learnt something from. Even if the research needs more work, there is a chance that in time, the atlantic conveyor MAY shutdown, possibly due to global warming. In which case our climate may change for the cooler. I do respect your opinion though and am glad to hear it, always something to learn!

Not sure that I know you? Not in the air force were you?

Cheers, rib.