Sceptic Links Discussion

[Pennine Ten Foot Drifts]

Quite, so maybe the old saying about 'if you stick your head above the trench..............' is in this case solid advice

[Admiral_Bobski]

I see it has been a quiet day on this thread today! Ah well - onwards and upwards tomorrow.

I've been out all day, enjoying the summertime rain, but I've spent the past hour or so reading through Bob Carter's paper again and compiling notes. I hope to post my first few comments tomorrow, for anyone who is interested...

Good night folks!

CB

[HighPressure]

I see it has been a quiet day on this thread today! Ah well - onwards and upwards tomorrow.

I've been out all day, enjoying the summertime rain, but I've spent the past hour or so reading through Bob Carter's paper again and compiling notes. I hope to post my first few comments tomorrow, for anyone who is interested...

Good night folks!

:lol:

CB

Always interested to read your thoughts Captain, I think 'Dev' may have done away with himself, either that or his plotting to have you put in the tower

I was hoping that P3 would get involved from the Pro side as I find his thoughts well worth a read because its not just throwing toys out of prams.

[Admiral_Bobski]

Always interested to read your thoughts Captain, I think 'Dev' may have done away with himself, either that or his plotting to have you put in the tower

I was hoping that P3 would get involved from the Pro side as I find his thoughts well worth a read because its not just throwing toys out of prams.

Thank you HP, that's very kind of you. I've compiled a selection of quotes and comments now, but I shall post them tomorrow (morning, I hope) because I'm far too tired to do the necessary spelling and grammar checks right now!

I do hope that Devonian comes back and enters the debate properly, because I really do want to understand his point of view - whether I agree with it or not... (And if anyone's going to put me in the Tower then they'll have to catch me first! )

I also hoped that P3 would come on board - there's a guy whose opinion I respect, even if, again, I don't necessarily agree with him. Hopefully he'll join in when he sees something that interests him enough!

Right, well I really am off to bed now, so I'll catch up with y'all tomorrow.

G'night!

:lol:

CB

[Roger J Smith]

I still feel that the actual outcome here may be obscured by the way the debate is playing out so far.

The "actual outcome" to which I refer is this possibility -- we are in the middle of a strong natural warming period which may be enhanced by the greenhouse components, but could in any case be strong enough without our presence to lead to substantial climate change.

If that were the case, the current political debate may be dangerous in that it suggests a possible way out of this climate change through changes in greenhouse gas production alone. If that's not actually the case and this warming is inevitably going to melt substantial parts of the arctic ice in 30-50 years, then we won't be focused on that inevitability and instead we will be racing forward with a highly controversial and arguably futile program of possibly very disruptive economic interventions, while sea levels will be rising anyway and the actions required to adjust to that reality are postponed because they are not politically correct (as in "we shouldn't focus on that because it fails to address the problem.")

I am not certain that the natural warming will continue long enough or with enough intensity to bring about these changes, but I think it is possible. And I believe that what our governments should do is to concentrate on this possibility, plan around one or two metre sea level rises and take all the necessary actions to reduce the harm that might be done to infrastructure and the economy by such rises, taking into account that reducing greenhouse gas emissions won't hurt the cause, but not expecting that alone to have a preventative effect.

For the same reasons, it is essential that we do not turn a blind eye to particle-based pollution from eastern Asia because this ends up in the western arctic basin and can, independent of atmospheric temperature increases, accelerate melting of the arctic ice pack through albedo changes. It is for this reason that I am wary of the Kyoto process since I think it postpones for too long a period any substantial incentive to change in eastern Asia at the expense of western economies which are expected to take almost draconian measures.

The problem with all this is that separating out the natural from the anthropogenic warming is not very easy and this is really where the debate should be centered, those who enter the debate and say well it isn't really warming up at all, distort that and add what I would call a rogue element, at least for the time being. There could very well be a period down the road when a natural cooling cycle sets in and at least more or less demonstrates where the bulk of the current warming was actually entering the atmosphere-ocean system. The reality is bound to be some complicated mixture of natural and greenhouse based warming, although right now it seems to be more of an absence of both outside here, and from what I'm seeing, there too.

My own point of view here seems to be a very small minority position, I have not heard anyone saying this in the larger public debate (this being "it's going to warm up anyway so let's plan for that") ... but at least nobody had to spend ten billion dollars to get this opinion. You can have it for free and start moving the valuable stuff upstairs, or out of harm's way, near the lower elevations of the coastal districts. I think that sea levels will rise by half a metre by 2020 and a full metre by 2040 at the latest, regardless of what we do about carbon dioxide emissions. And I predict that if that happens, the AGW lobby will claim it happened because of our failure to act in this decade, but possibly not, because perhaps some better scientific framework will be established and the science will know how to distinguish between natural and anthropogenic warming by 2020.

[Devonian]

Always interested to read your thoughts Captain, I think 'Dev' may have done away with himself, either that or his plotting to have you put in the tower

I was hoping that P3 would get involved from the Pro side as I find his thoughts well worth a read because its not just throwing toys out of prams.

Sticks and stones my friend, sticks and stones...

Have you read the links I gave?

Edited June 25, 2007 by Devonian

[Devonian]

Thank you HP, that's very kind of you. I've compiled a selection of quotes and comments now, but I shall post them tomorrow (morning, I hope) because I'm far too tired to do the necessary spelling and grammar checks right now!

I do hope that Devonian comes back and enters the debate properly, because I really do want to understand his point of view - whether I agree with it or not... (And if anyone's going to put me in the Tower then they'll have to catch me first! )

I also hoped that P3 would come on board - there's a guy whose opinion I respect, even if, again, I don't necessarily agree with him. Hopefully he'll join in when he sees something that interests him enough!

Right, well I really am off to bed now, so I'll catch up with y'all tomorrow.

G'night!

CB

My point of view is that I accept, and have done for many years, the consensus view of the science. I see warming, I see increased ghg/land use changes - all anthropogenic. I see reasoned, sound scientific arguments advanced to back up the link between the two, and I see soundly based predictions for the future that so far seem to be coming true. There is stacks out the people can read on this - the Met Office library is a good starting place as is the Hadley Centre. It's the wisdom of the Met Office, Hadley, universities, NOAA, IPCC, CRU, NCDC. OK, there is dissent but I clearly don't agree with it's view.

OK?

Edited June 25, 2007 by Devonian

[Admiral_Bobski]

My point of view is that I accept, and have done for many years, the consensus view of the science. I see warming, I see increased ghg/land use changes - all anthropogenic. I see reasoned, sound scientific arguments advanced to back up the link between the two, and I see soundly based predictions for the future that so far seem to be coming true. There is stacks out the people can read on this - the Met Office library is a good starting place as is the Hadley Centre. It's the wisdom of the Met Office, Hadley, universities, NOAA, IPCC, CRU, NCDC. OK, there is dissent but I clearly don't agree with it's view.

OK?

Okay, let me rephrase - it's quite clear what your point of view is, but I want to discuss the science to see why you hold that point of view. I want to learn whether (and forgive me if this seems overly aggressive as it isn't intended to be) you actually understand what you're being told or if you just accept it because "it came from respectable bodies so must therefore be true".

And, as I have said before, I love talking about and discussing science. Science is more about facts than any other human endeavour, and discussing facts is fascinating - discussing politics or history or music or art is far more interpretive and opinion-based, and discussions on these subjects are therefore much more likely to get heated.

I shall soon be posting my first few points regarding the Bob Carter paper, and I look forward to hearing people's views.

CB

EDIT - PS - What predictions have you seen come true?

Edited June 25, 2007 by Captain_Bobski

[jethro]

Good Morning everyone.

Roger, you make a very valid point, and one I myself have made previously (although far less eloquently); my concerns with the IPCC focus primarily upon this point. I don’t want this to degenerate again into tit for tat regarding the integrity of the report but it is at the end of the day, the foundation document upon which governments will base their decisions.

Having first approached this whole debate from a believer in AGW stance, it was only upon my own further investigation, to understand it more comprehensively that I realised it isn’t as simple as us adding Co2. From all that I have read so far I have reached the conclusion that warming from a natural source outside of our control is also at work here too.

My thoughts on the Third World are already known here and I fully admit it is something I have strident feelings about. I am very concerned that the necessary actions required to protect some of the poorest nations from the impact of any climate change, will either be buried in the focus on reducing Co2 or be inadequate or too late. We only have to look at New Orleans and Katrina for full demonstration of the impact of inadequate actions.

When it comes to the previous point raised by Pennine, my stance is slightly different than Capt’n Bs’; the science debate is for me of greater importance, namely for the reasons outlined above. If the science is incomplete, wrong, skewed or just too focussed upon our input then our knowledge and understanding of the necessary actions to take now, will be seriously compromised. If all our energy is focussed upon reducing Co2 and the world continues to warm regardless and we do not expect this or have not adequately added this factor to the equations then we will not be prepared for the potentially catastrophic changes which may happen.

I also believe if we go down the road of basing major monetary and political decisions upon science and research which is possibly incorrect or incomplete and the scientific knowledge is shown at a later date to be flawed or misrepresented, then this will result in serious issues of lack of confidence. Science should either be right, wrong or incomplete/unproven and presented as such. If there has been an element of pressure from governments or the IPCC to present a complete theory or package of actions needed with the known knowledge to date then the scapegoat at the end of the day will be the scientific community. I can’t imagine a politician on earth putting their hand up and saying “we got it wrong” but I can, quite easily imagine a whole load of finger pointing and “we did what they said we needed to do, they were wrong, not us”.

[Admiral_Bobski]

Okay, here's my first few points from the Bob Carter paper. The first is a clarification of the "Climate Research" expenditure point brought up by Iceberg a few days ago.

...how much do we know about how climate works? The answer – as detailed in such useful references as Philander (1998), IPCC (2001), Ruddima (2001), Kininmonth (2004) and Singer and Avery (2006) – is ‘a very great deal, though not yet enough to predict its future with any certainty’. And we would certainly hope that the first part of this answer were true, because at least US$50 billion dollars has been expended on climate change research since 1990.

It seems quite clear that he is saying that the $50 billion has been spent on climate research as a whole, and is not claiming that all of that money has been spent solely on AGW research. The point he is trying to make, I think, is that despite $50 billion being spent on climate research we still don't actually understand climate a great deal, and we certainly don't understand it enough to be able to give any definitive predictions for future climate.

Hurd (2006), Jaworowski (2007) and others have argued that [the CO₂ levels in ice cores] are about 30 - 50 per cent lower than the original atmospheric values that they purport to represent, because of the post-depositional diffusion and mixing that occurs within the compacting ice mass.

I first read about this about three or four months ago, and it seemed to me to be a reasonable proposition - although the air bubbles in Ice Cores are in some sense sealed in the ice, there really isn't any such thing as an airtight seal at the molecular level. CO₂ molecules will bounce around inside these air pockets and, as is the way at the molecular level, react chemically with the surrounding ice. Once those molecules have reacted they may bond to the ice, but this bond is far from permanent - in fact ice isn't particularly keen on accepting other molecules into its matrix because it is locked up so tight (which is one of the reasons why icebergs are composed of freshwater) - and some of the CO₂ molecules will, over time, dissipate through the ice, perhaps even to the point of reaching the ice surface and then freeing themselves into the atmosphere.

Add to this the fact that the CO₂ levels spoken of are averages, and that the vast majority of the atmospheric CO₂ is suspended in a layer some distance above the ground. If the ice formed air pockets then those pockets must have formed at ground level, which introduces another level of uncertainty in the estimations of historic CO₂.

Together with oxygen, carbon dioxide is a staff of life for earth’s biosphere because the metabolism of plants depends upon its absorption. Increasing carbon dioxide in the range of about 200 - 1000 ppm has repeatedly been shown to be beneficial for plant growth, and to increase plants’ efficiency of water use (Eamus, 1996; Saxe, Ellsworth and Heath, 1998; Robinson et al, 1998). Prima facie, therefore, there is no reason to assume that atmospheric carbon dioxide levels of 500 - 1000 ppm are dangerous, or that such levels would have dramatically adverse ecological effects.

The point at which CO₂ stops being beneficial to plants has been brought down in the past few years, and I must do some more investigating into why this is the case. (Surely if, say, 850ppm of CO₂ is harmful to plants now then it would have been similarly harmful in 1996 or 1998, so why the reduction?) However, this is as good a point as any to raise the issue (again!) that CO₂ can hardly be claimed to be a pollutant. If CO₂ can be labelled a pollutant due to the fact that excessive levels of it may be toxic, then Oxygen should be similarly labelled. Too much Oxygen goes into a human body and you're dead - our bodies filter out excess oxygen, up to a point. The concentration of Oxygen in a human body is approximately one tenth of the concentration of Oxygen in the atmosphere. Give a body more Oxygen than it can filter and you get a dangerous build-up in your body.

So as not to make this post over-long I am going to leave it at that for now. I shall post more points when these have been discussed.

CB

[Devonian]

Okay, let me rephrase - it's quite clear what your point of view is, but I want to discuss the science to see why you hold that point of view. I want to learn whether (and forgive me if this seems overly aggressive as it isn't intended to be) you actually understand what you're being told or if you just accept it because "it came from respectable bodies so must therefore be true".

No, it's my understanding of it. I don't pretend to know better than those bodies I quote. I'm not going to be provoked by your last sentence, bar saying it's an approach I've often seen.

Edited June 25, 2007 by Devonian

[Admiral_Bobski]

No, it's my understanding of it. I don't pretend to know better than those bodies I quote. I'm not going to be provoked by your last sentence, bar saying it's an approach I've often seen.

Oh for crying out loud - I'm not trying to provoke you in the slightest.

If you're not going to discuss science on what is essentially a science discussion forum then I shall discuss the science with those who will.

[jethro]

No, it's my understanding of it. I don't pretend to know better than those bodies I quote. I'm not going to be provoked by your last sentence, bar saying it's an approach I've often seen.

Dev, as you have read a great deal from legitimate sources, has there been any point at which you've thought "hang on a minute, that doesn't quite add up" or "ah but what about.....?", if so, which part of the accepted science made your question appear?

[Iceberg]

As I've said before the talk of whether CO2 is a pollutant or not is kind of irrelavent IMO. But a def of pollutant is.

"Air Pollution is a chemical, physical (e.g. particulate matter), or biological agent that modifies the natural characteristics of the atmosphere. "

By increasing the amount of CO2 in the atmosphere you could argue it's modifying the effects/charecterics of the atmosphere. I don't really think it's worth discussing though as it's really a semantic and will depend on your view of the AGW.

[Admiral_Bobski]

As I've said before the talk of whether CO2 is a pollutant or not is kind of irrelavent IMO. But a def of pollutant is.

"Air Pollution is a chemical, physical (e.g. particulate matter), or biological agent that modifies the natural characteristics of the atmosphere. "

By increasing the amount of CO2 in the atmosphere you could argue it's modifying the effects/charecterics of the atmosphere. I don't really think it's worth discussing though as it's really a semantic and will depend on your view of the AGW.

Fair enough - I personally think the definition of CO₂ as a pollutant is irrelevant to the scientific debate, but of some relevance to the political debate.

That said, as I wrote in my last post, I want to discuss science so I shall drop the "CO₂ as pollutant" issue now.

What are your thoughts on the accuracy of the ice core record in determining historic CO₂ levels?

CB

[noggin]

What are your thoughts on the accuracy of the ice core record in determining historic CO₂ levels?

CB

I have often wondered about ice core samples. If the "deepest" parts are thousands of years old, will there not have been a great deal of compression over time and if so, how sure can we be of the "timings"?

[Admiral_Bobski]

I have often wondered about ice core samples. If the "deepest" parts are thousands of years old, will there not have been a great deal of compression over time and if so, how sure can we be of the "timings"?

Exactly noggin. I have yet to find anywhere that explicitly describes how they attribute CO₂ levels to ice core air pockets, but it would appear that some do not believe that enough is taken into consideration when making their determinations.

EDIT - 400,000 years is a long time for chemical processes to occur in...!

CB

Edited June 25, 2007 by Captain_Bobski

[Iceberg]

Just doing a quick read of Jaworowski (2007).

First impressions indicate that this isn't a scientific paper at all but another personal report.

Personally I am uncomfortable relying on any science that isn't objectivily looked at. The peer review process should be the mechanism for this.

Also It seems to be a house of straw that's built, each report quotes each other report, which then quotes and builds up, but not of the reports are peer reviewed.

I am not comfortable with the science to be able to say yea or nay to it, but from the reports (pro and anti) the most professional with the most scruitany is the IPCC line.

FWIW I am not happy with randomally selected C02 measurements over the last 100 years these from memory include industrial sites in Germany etc.

[Admiral_Bobski]

Just doing a quick read of Jaworowski (2007).

First impressions indicate that this isn't a scientific paper at all but another personal report.

Personally I am uncomfortable relying on any science that isn't objectivily looked at. The peer review process should be the mechanism for this.

Also It seems to be a house of straw that's built, each report quotes each other report, which then quotes and builds up, but not of the reports are peer reviewed.

I am not comfortable with the science to be able to say yea or nay to it, but from the reports (pro and anti) the most professional with the most scruitany is the IPCC line.

FWIW I am not happy with randomally selected C02 measurements over the last 100 years these from memory include industrial sites in Germany etc.

I shall do some further digging - I can't remember where it was that originally read about this but I'm reasonably sure it wasn't the Jaworowski paper, and I know that Jaworowski isn't alone in this proposal. I'll see what I can find.

Either way it seems prudent for scientists to make a concerted effort to make accurate determinations of historic CO₂ levels. I appreciate that these levels are determined from a variety of proxies, but each has an associated error margin that extends to well below the presumed levels and well above the current levels. Narrowing that error margin seems a reasonable way forward.

CB

[Devonian]

Either way it seems prudent for scientists to make a concerted effort to make accurate determinations of historic CO₂ levels.

CB

CB, I can only guess you don't know of the sheer amount of hugely time consuming and painstaking work that's been put into determining the ice core record?

To criticise the work of others one surely has to at least be familiar with what they did and how they did it? I'm not all that familiar with it, but I do know work on ice cores is extensive, detailed, scrutinised, repeated several times and shown to be sound. To write as you do above simply, well, it takes my breath away.

[jethro]

CB, I can only guess you don't know of the sheer amount of hugely time consuming and painstaking work that's been put into determining the ice core record?

To criticise the work of others one surely has to at least be familiar with what they did and how they did it? I'm not all that familiar with it, but I do know work on ice cores is extensive, detailed, scrutinised, repeated several times and shown to be sound. To write as you do above simply, well, it takes my breath away.

QUOTE(Devonian @ 25 Jun 2007, 09:47 AM) *

No, it's my understanding of it. I don't pretend to know better than those bodies I quote. I'm not going to be provoked by your last sentence, bar saying it's an approach I've often seen.

Dev, as you have read a great deal from legitimate sources, has there been any point at which you've thought "hang on a minute, that doesn't quite add up" or "ah but what about.....?", if so, which part of the accepted science made your question appear?

[Admiral_Bobski]

Well, since the first set of comments yielded very little I shall move onto the next batch.

...the relationship between increasing carbon dioxide and increasing temperature is logarithmic, which lessens the forcing effect of each successive increment of carbon dioxide (Figure 4). Second, in increasing from perhaps 280 ppm in pre-industrial times to 380 ppm now, carbon dioxide should already have produced 75 per cent of the theoretical warming of ~1°C that would be caused by a doubling to 560 ppm (Lindzen, 2006); as we move from 380 to 560 ppm, at most a trivial few tenths of a degree of warming remain in the system.

If this is correct then there's only a limited amount of warming yet to come (assuming CO₂'s theoretical effect is accurate). Beside that, though, there's the interesting point that the link between CO₂ and temperature is logarithmic - interesting because the Ice Core records show no such logarithmic correlation, but show instead a linear correlation which seems more to support the idea that CO₂ has increased as a result of temperatures increasing and not vice versa.

Boucot, Xu and Scotese (2004) have shown that over the Phanerozoic little relationship exists between the atmospheric concentration of carbon dioxide and necessary warming, including that extensive glaciation occurred between 444 and 353 million years ago when atmospheric carbon dioxide was up to 17 times higher than today.

I confess I haven't checked this out, but assuming it's true it would seem to somewhat knock the influence of CO₂ on temperatures. (Obviously people will bring up a variety of issues, such as different arrangement of continents, different ocean currents and a cooler Sun, but if CO₂ was seventeen times higher then one would have expected a certain negation of these effects.)

Individual GCMs differ widely in their output under an imposed regime of doubled carbon dioxide. The IPCC (2001,

Figure 5d) cites a range of 1.8 to 5.6°C warming by 2100 for the model outputs that they favour, but this range can be varied further to even include negative outputs (ie cooling) by minor adjustment of some of the model parameters (Essex and McKitrick, 2002). When climate modelling experiments produce such cooling, the output is discarded as ‘obviously wrong’ (Stainforth et al, 2005).

Skeptics are often accused of cherry-picking data, but the simple fact is that everyone cherry-picks data to some extent. If such output as mentioned above is discarded as "obviously wrong" then there's an evident bias - surely it would be more appropriate to determine why such outputs occurred rather than dismissing them?

Well, there's three more points - more to come when we've finished with these ones...

CB

[trevw]

If this is correct then there's only a limited amount of warming yet to come (assuming CO₂'s theoretical effect is accurate). Beside that, though, there's the interesting point that the link between CO₂ and temperature is logarithmic - interesting because the Ice Core records show no such logarithmic correlation, but show instead a linear correlation which seems more to support the idea that CO₂ has increased as a result of temperatures increasing and not vice versa.

isn't that the link between CO2 and temperature without feedbacks included? the effect of CO2 is bound to reach a saturation point when there is no more radiation at the right frequency to absorb/scatter? I thought that the issue was that the 'forcing' caused by CO2 was relatively small but that it still changes the temperature minutely upwards, this causes water vapour levels to rise until a new equilibrium is reached and then it is the water vapour that causes the majority of the actual warming even though it is just a feedback mechanism.. thus a few tenths of a degree aren't trivial?

Also a great deal of the 'trapped' heat energy would surely get absorbed by the seas and pulled into the deep ocean circulation causing a delay in its effect on the climate.. so the temperature rise we are seeng now is being caused by the rises in the early half of the next century?

I confess I haven't checked this out, but assuming it's true it would seem to somewhat knock the influence of CO₂ on temperatures. (Obviously people will bring up a variety of issues, such as different arrangement of continents, different ocean currents and a cooler Sun, but if CO₂ was seventeen times higher then one would have expected a certain negation of these effects.)

again my take on this would be (with a pro AGW hat on) that CO2 as a forcing is not massive and if the climate were not in a state where feedbacks were poised to kick in then maxing out CO2 would potentially just slightly mitigate the coldness of the climate. Also, in this instance the presence of high levels of CO2 is presumeably just a feedback mechansim (unless caused by something 'external' to the climate itself such as super volcanoes or methane hydrates etc)

Skeptics are often accused of cherry-picking data, but the simple fact is that everyone cherry-picks data to some extent. If such output as mentioned above is discarded as "obviously wrong" then there's an evident bias - surely it would be more appropriate to determine why such outputs occurred rather than dismissing them?

agreed, humans seem hard-wired to try and pick/test data to re-inforce their held opinions rather than try to disprove them, this 'syndrome' has a name (which escapes me at the moment). However on the model changes in question, I was under the impression that such cooling could not be achieved from the models without compromising their ability to predict the climate over the past century or so.. which is obviously a bit of a stumbling block.

Trev

(couldn't quote the quotes from your post, not sure why)

[Admiral_Bobski]

isn't that the link between CO2 and temperature without feedbacks included?

Probably this is the direct relationship, which wouldn't take into account other feedbacks, but it seems strange that other feedbacks would be able to perfectly iron out the logarithmic correlation to the extent that there wasn't even the tiniest hint that it was ever there. There seems to me something deeply "wrong" with the Vostok Ice Core CO₂/temperature graph. Not wrong in the sense of "incorrect" or "tampered with" but wrong in the sense that it doesn't seem to fit in with the AGW hypothesis, much less actualy support it.

again my take on this would be (with a pro AGW hat on) that CO2 as a forcing is not massive and if the climate were not in a state where feedbacks were poised to kick in then maxing out CO2 would potentially just slightly mitigate the coldness of the climate. Also, in this instance the presence of high levels of CO2 is presumeably just a feedback mechansim (unless caused by something 'external' to the climate itself such as super volcanoes or methane hydrates etc)

Indeed, it is a rather more complicated situation than it would seem (and I confess it is presented in a rather simple way in the paper, but that doesn't necessarily negate its fundamental truth...assuming it is true, of course! ) This is something I am keen to look into further - I don't see that the different positioning of the continents in the distant past, or the relative coolness of the sun (which wasn't a great deal cooler, it must be said), should be an insurpassable obstacle to making sensible comparisons, but I need to study it rather more.

agreed, humans seem hard-wired to try and pick/test data to re-inforce their held opinions rather than try to disprove them, this 'syndrome' has a name (which escapes me at the moment). However on the model changes in question, I was under the impression that such cooling could not be achieved from the models without compromising their ability to predict the climate over the past century or so.. which is obviously a bit of a stumbling block.

Again, an area I need to study in greater depth (I suppose all areas of climate require more study on my part, but if they didn't then I guess I'd be a climate scientist!). What I do know of the models, and of computer models in general, is that their output is dependent on their input. This sounds rather obvious, and it is, I grant you, but what this means is that you can enter any variables you like to produce the desired output. As such, models are great in some ways at helping us understand certain processes, but if one focuses on only adjusting the variables one "wants" to be pertinent then the results will be intrinsically biased - you can guarantee that you'll find some solution using only the variables you're interested in, but that doesn't necessarily make that solution the correct one.

Thanks for taking the time to write back, trev!

CB

[HighPressure]

I am not a scientist so I simple ask whether the following article is right or wrong? Other reading seems to suggest that the IPCC were very selective in the Ice data they chose to include in their report. Please don't have a go at me or just discredit the sources as part of my learning process I would like to the Pro response?

About Antarctica, University of Virginia climate scientist Patrick J. Michaels is direct: “What has happened is that Antarctica has been gaining ice.” He explains that there has been a cooling trend over most of Antarctica for decades. At the same time, one tiny portion of the continent — the Antarctic Peninsula — has been warming, and its ice has been melting. The peninsula constitutes only about 2 percent of Antarctica’s total area, but almost every study of melting Antarctic ice you’ve heard of focuses on it.

So what about the rest of the continent? In 2002, Nature published a study by Peter Doran that looked at Antarctic temperature trends from 1966 to 2000. What it found was that about two-thirds of Antarctica got colder over that period. At the same time, Antarctica has gotten snowier, and as the snow has accumulated the ice sheet has grown. Snowfall is probably rising because water temperatures around Antarctica have gotten slightly — repeat, slightly — warmer. As a result, there is more surface evaporation, making for higher humidity and more precipitation. Higher humidity also means more clouds, which might explain the cooler weather.

How much ice has Antarctica gained? In a 2005 study published in Science, Curt Davis used satellite measurements to calculate changes in the ice sheet’s elevation, and found that it gained 45 billion tons of ice per year between 1992 and 2003. Far from flooding the coasts, that’s enough to lower sea levels by roughly 0.12 millimeters annually.

This doesn’t mean the trend of increasing Antarctic ice will continue forever. Science captured headlines in March when it published a study by Isabella Velicogna arguing that, between 2002 and 2005, Antarctica has been losing ice mass. Velicogna used a pair of satellites to measure the gravitational pull exerted by the Antarctic ice sheet, which in turn allowed her to calculate its mass. Her data suggest that, over the past three years, the sheet has lost about 152 cubic kilometers of ice per year. That would be the equivalent of about 0.4 millimeters of annual sea-level rise.

But three years do not a trend make. To begin with, such a short sampling period is a blip in the slow rhythms of climate change. Moreover, 2002 — the year in which the study began — was a high-water mark for Antarctic ice, so it’s not too surprising to see some decline since then. Alarmism over Velicogna’s study is on the order of going to the beach at high tide, drawing a line at the water’s edge, and fretting a few hours later that the oceans are drying up.

And Greenland? Various studies show that warmer temperatures are causing the ice sheet there to lose mass at the margins. But, as in Antarctica, higher sea temperatures are also causing greater snowfall and building up ice in the interior. As Richard Lindzen of MIT observes, “If you’re just going to look at what’s falling off the sides and ignore what’s collecting on top, that’s not exactly kosher.” The question is whether the net change is positive or negative.

Earlier this year, Eric Rignot and Pannir Kanagaratnam published a study in Science that used satellite measurements to calculate ice loss around Greenland’s coasts. They also used models to determine how much ice was vanishing from surface melt, and how much was accumulating from greater snowfall. Adding it all up, they got a decade of deficits: 91 cubic kilometers of ice lost in 1996, rising to 224 cubic kilometers in 2005. That translates to a sea-level rise of 0.23 millimeters in 1996 and 0.57 millimeters in 2005.

But, as the web publication CO2 Science has pointed out, their model-based estimate of the ice gain in Greenland’s interior was implausibly small. In fact, Science had earlier published a study by Ola Johannessen that used satellite measurements to determine how much the ice sheet was growing. Johannessen found that, between 1992 and 2003, it was gaining on average 5.4 centimeters of elevation per year.

That may not sound like a lot, but it adds up. Michaels, the University of Virginia professor, calculates that it amounts to about 74 cubic kilometers of ice per year. Rignot and Kanagaratnam could have subtracted that number from their estimate of coastal ice loss, which would have given them a negative total only for the past five years: 17 cubic kilometers lost in 2000, rising to 92 cubic kilometers in 2005. That would be equivalent to only 0.04 millimeters of sea-level rise in 2000 and 0.23 millimeters in 2005.

Add all the numbers from Greenland and Antarctica up, and you get a rather piddling total. In 2005, Jay Zwally of NASA published a study in the Journal of Glaciology that looked at the ice-mass changes for both Greenland and Antarctica from 1992 to 2002. He concluded that the total ice loss was equivalent to a sea-level rise of just 0.05 millimeters per year. At that rate, it would take the oceans a millennium to gain 5 centimeters, and a full 20,000 years to rise by a meter. To the hills, anyone?

A LONGSTANDING PATTERN Granted, the Zwally study doesn’t include the last three years — years in which, according to some measurements, Antarctica has switched from gaining ice to losing it, and Greenland’s rate of loss has accelerated. But you don’t need to invoke man-made global warming to explain what’s going on.

Consider Greenland again. Yes, temperatures there are warmer than they were a decade ago. But many climate scientists think this is the result of a phenomenon called the Atlantic Multidecadal Oscillation (AMO) — a pattern of slow, repeating changes in the ocean’s surface temperatures. The AMO affects both the Atlantic tropics and the regions farther north. When the AMO is in its positive phase, temperatures rise in both places — which should cause more Caribbean hurricanes, and increase the speed at which Greenland’s glaciers discharge into the sea. This appears to be just what is happening. “The AMO changed from negative to positive in 1995,” Michaels wrote on Tech Central Station. “Since then hurricanes have become very active and glacier output has been accelerating.” Is this man’s fault? Models suggest that the AMO has been going on for at least 1,400 years. Maybe things would have turned out differently had Charlemagne signed the Kyoto Protocol, but the odds are against it.

In fact, we have temperature records indicating that Greenland was as warm as it is today during the first half of the 20th century. From 1920 to 1930, Greenland saw significant warming, and temperatures stayed high through the ’40s. A team of scientists led by Petr Chylek looked at Greenland’s temperature record in a study forthcoming from Geophysical Research Letters. They write that the increase in Greenland’s temperature between 1920 and 1930 was “of a similar magnitude” to the increase between 1995 and 2005. But the earlier warming happened faster: “The rate of warming in 1920–1930 was about 50% higher.” 2003 was a hot year, but “the years 2004 and 2005 were closer to normal[,] being well below temperatures reached in [the] 1930s and 1940s.” Moreover, “although . . . 1995–2005 was relatively warm, almost all decades within 1915 to 1965 were even warmer.”