General Climate Change Discussion Continued:

[Iceberg]

My apologies if this has already been covered ...

The ocean/atmosphere coupling is the radiator, and, physically, is the sea surface temperature (first two metres?) This is affected by two sources of heating. Firstly, as I suspect is being discussed, here, is the atmosphere, and secondly, it is also the case that it is affected by deep sea water (> 2 metres?)

Deep sea water currents are driven down, in some cases, by the THC to very deep levels and that water does not surface for many many years. If this is the case, and I am no oceanographer, then it seems perfectly reasonable to set out a hypothesis such that SST are affected by insolation levels of many a year ago.

For instance, on that basis it seems reasonable that there might be a variable lag between sun activity and the ocean/atmosphere coupling temperature; indeed dCO₂/dT might amplify this in a complex, but understandable fashion (see Role of deep sea temperature in the carbon cycle during the last glacial, Pamela Martin, David Archer, David W. Lea, PALEOCEANOGRAPHY, VOL. 20, PA2015, doi:10.1029/2003PA000914, 2005)

I agree VP, which is why instead of SST's we talk about OHC (Ocean Heat content), the top layer of the ocean contains something like 95% of the heat, there is also very little mixing to lower depths, however I think it's pretty well agreed that the top 2km of the oceans is probably the warmest we've ever recorded recently (notably Jan 2010), with this in mindthe radiator has not shown any cooling, ergo the heating is still on, ergo solar isn't the heating, or isn't much of the heating ?.

[Solar Cycles]

I have read the links you gave SC re radiators, I was tempted to reply with a law of physics, i.e heat goes from the warm object to the cold object and not vice versa, re the effects of heated deep ocean water below 2KM as per the links, but I want to read up a little more first.

No problem Iceberg, VP explained it better than me up above!

Just seen your post above!

The melting ice I was referring to was ice sheets, rather than sea ice/pond ice - the feedback mechanism goes like this: Melt some ice, you lower the altitude of the ice surface, so it will melt more easily next year, as well as reducing its albedo. The evidence is in the rapidity of the Quaternary glaciation terminations in relation to the relative slowness of their advance. Glacier ice can melt much more rapidly than it can accumulate, hence why ~60% of your average mountain glacier is in the accumulation zone if its mass balance is in equilibrium. With ice sheets, you can get a catastrophic collapse once the ice surface begins to drop, as there is no way to raise the surface level of the ice without a huge temperature drop. But about your pond: if the nights were -10C for 4 nights, and the day temps were +5C (a generalisation I know), then it may be quite reasonable for the melting to take a long time, if it was less intense than the freezing (each one in the example has 40 degree-days of melting/freezing).

And I'm with you on the oceans not losing their spare heat quickly, but the crucial thing is whether they are actually still accumulating heat. CB, I think ocean heat content levelled off or dropped a bit in the last few years, but has tended to rise in a similar manner to surface temperatures. Namely that the oceans are capable of short-term drops in heat within a longer rising trend, just as the land is.

http://earthobservat...s/OceanCooling/

http://www.skeptical...ocean-heat.html

Some interesting observations in there, but I think, it shows an area in which more data is required, and is being collected at quite a rate, in order to conclusively show all the processes at work here (as highlighted by the researchers, and by IPCC).

Levitus, from the NASA article: "My point is just that we need to remain open-minded because it may be that it is possible for the ocean to gain heat and lose it more rapidly than we think. There may be other phenomena [similar to El Niño] operating on different time scales that can explain interdecadal increases and decreases," says Levitus. Even if these ups and downs don't change the long-term destination of global warming, they could reveal more detail about what kind of ride we can expect."

sss

Thanks sss,, I'll read those links when I've more time.

Edited February 9, 2010 by Solar Cycles

[VillagePlank]

the top 2km of the oceans is probably the warmest we've ever recorded recently (notably Jan 2010), with this in mindthe radiator has not shown any cooling, ergo the heating is still on, ergo solar isn't the heating, or isn't much of the heating ?.

I would say - actually, hypothesize - that the heating of the ocean is the emergence of the excessively active sun over the last 50 years. ie the surface was warmed by the sun, ocean currents took some of that heat and buried it very very deep. A few years later, somewhere else along the THC conveyor (which, of course, is global) that current resurfaces. The point about poor mixing (probably due to massive densities that far under water) is critical.

[Methuselah]

I would say - actually, hypothesize - that the heating of the ocean is the emergence of the excessively active sun over the last 50 years. ie the surface was warmed by the sun, ocean currents took some of that heat and buried it very very deep. A few years later, somewhere else along the THC conveyor (which, of course, is global) that current resurfaces. The point about poor mixing (probably due to massive densities that far under water) is critical.

That, VP, makes perfect sense to me: poor mixing being the main thing about the THC... :lol:

What is the 'residence time' for a newly-sunk water-salt mix???

[Solar Cycles]

I would say - actually, hypothesize - that the heating of the ocean is the emergence of the excessively active sun over the last 50 years. ie the surface was warmed by the sun, ocean currents took some of that heat and buried it very very deep. A few years later, somewhere else along the THC conveyor (which, of course, is global) that current resurfaces. The point about poor mixing (probably due to massive densities that far under water) is critical.

Yeah, that was what I was trying to put across VP, thanks!

[Devonian]

I would say - actually, hypothesize - that the heating of the ocean is the emergence of the excessively active sun over the last 50 years. ie the surface was warmed by the sun, ocean currents took some of that heat and buried it very very deep. A few years later, somewhere else along the THC conveyor (which, of course, is global) that current resurfaces. The point about poor mixing (probably due to massive densities that far under water) is critical.

It's a idea worth exploring. I'm rather bothered that it happens at the same time and mimics you know what :lol: , so I think it has to be nailed down to a time scale else everything that happens in the future can be explain by saying some other bit of warmth has emerged somewhere - so I'm asking for a mechanism to explain specific lengths of lag (LI of course?) else I'm going to be, cough, sceptical (not dismissive, sceptical - as I think I should be?).

Anyway, what do you make of the graph here for example?

[Guest North Sea Snow Convection]

Another busy day here! But I think maybe some progress? I'm not going to comment much on the argument I've spawned between NSSC, Dev and TWS and others - but only to make the point once more. I'm looking for evidence that can alter my opinion, and I am open to my opinion being altered if the evidence is there. Not proof (if I used that word in an earlier post it was erroneous - a body of work can't be 100% accurate can it? ). Anyway, I've many times states I'm looking for evidence, and that the notion of 100% proof is not sensible. To those who defended my position - thanks! I certainly do not think it's arrogant to ask for some evidence for an opposing view, otherwise how am I to accept the opposing view?

And NSSC, you're right, I am not God If I was, AGW wouldn't be happening and I would have other means than an Internet forum to persuade you that what I believe is correct .

On radiators: if you turn the heat source off, how can the radiator possibly continue to heat up? Is that not breaking certain physical rules, given that the radiator is warmer than its surroundings. We're not talking about a system where the "boiler" is far from the radiator and so there would be a time lag as the last bit of hot water arrived in the radiator, as presumably the argument would be that the radiator (ocean) is being directly heated by the Sun. Provided the total heat content of the oceans is still rising, then the 'radiator' hypothesis should be invalidated? I'm not absolutely certain on the last part, but it makes good sense to me.

Negative feedbacks is a good one: My reading on it is that the negative feedbacks that do exist in the system (and have to exist) act in a slower manner than the positive feedbacks. It's much quicker to melt sea ice or an ice sheet than it is to grow one, for example (see the Quaternary ice volume record). And I think the core mechanism is the carbon cycle - the excess CO2 in the atmosphere will eventually be absorbed into the oceans or terrestrial carbon sinks, and turned into carbonate rock (ocean) or peat/coal/soil etc (terrestrial, via biomass). While the CO2 is in the atmosphere, it has the chance to trigger a series of relatively rapid positive feedbacks (water vapour, albedo, ice elevation, permafrost degradation), but eventually it will be reabsorbed into a reservoir somewhere, at which time the feedbacks will lose their impetus. So our problem is that we have set off the positive feedbacks by releasing huge amounts of carbon from their long-term reservoirs, but it will take a long time for the negative feedbacks to cancel out the positives. It doesn't mean that they are not there, it's just that the negative feedbacks don't operate powerfully on a short timescale. Most of the positive ones do.

Actually, on reflection, is absorption of carbon back into reservoirs truly a 'negative feedback'? It's really just something that switches off the 'positive feedbacks', rather than causing the process to operate faster than it otherwise would?

sss

I see your quoted post, but you have still asked me to prove you wrong on matters that are debateable depending on the science you believe.

As promised earlier, I am not going to answer the latest post from TWS that was inevitable I suppose in terms of having a last word.

It would be much fairer and less argumentative perhaps for this to be directed between us - without such others continuing to stick an oar in.

There is (at least should be) imo no obligation whatsoever on anyone to have to persuade someone to change their mind.

I guess I would never even give it a thought to seek to issue a gauntlet to others to convince me to change my mind. It would suggest to me that I would be adopting a stance that I am automatically right. That is where a perception of arrogance comes in perhaps? I think it is much fairer and much more realistic to allow people to develop their own opinions in their own time. Hence why I said to TWS that I would only change my mind when I see reason to - not when told to. The saying that you can take a horse to water but you cannot make it drink comes in here. People tend to reach consensus and meet others more in the middle with views when they are allowed the freedom to do so without coercion from others. People have to 'own' the information for themselves and assimilate it in such a way as to change or progress their view/opinion. It cannot be implemented in them like a computer programme by someome else.

Before you can decide whether negative feedbacks act slower than positive feedbacks you first have to be sure of which feedbacks in truth actually exist. I don't see how you can arrive at that sort of decison other than assuming that your theory is fully validated. Cart before the horse time again. You appear to speak here as if the existence and number of positive warmth amplyfying feedbacks is a given. AGW science indeed suggests they exist, but that doesn't mean it is true, or that everyone other than yourslef and other AGW believers should have any obligation themselves to believe it to be true. The raft of positive warmth amplifying feedbacks adopted by AGW are assumptive - again look at the clouds issue here for instance. If the number of overall positive feedbacks is assumptive it risks overlooking the presence of negative feedbacks that could make a large difference to the calculations/computer similation of solutions by the IPCC.

The list that CB provided wrt to the METO suggests to me that the data used is selective in fitting the purpose. You can always get a confirmation bias result from a computer if you feed it selective data in order to validate a theory. But is it the right data when based on such assumptions? Those assumptions have to be further tested to check their validity before one can start drawing conclusions about any further interaction and effect on climate.

In terms of do I think the scientists are 'stupid' to overlook some processes that might play a part in determining potential climate changes, then no, I wouldn't say that. However, as far as I am concerned there is a bias in terms of the data used that needs correction to arrive at a fuller, wider consideration of other influences beyond AGW.

You mentioned about the latest el nino and said something along the lines of it being as well that the latest event has not acted like the 1998 one and that changes to indices like the PDO etc have made no difference to temp changes. Temps have not risen for the last decade despite ever increasing CO2. This in itself doesn't disprove AGW but it doesn't vaildate it either. Also we need to remember that the projected warming estimates by the IPCC are signalled over multi decades not dtermined by short term annual variables. Even single decadal. On the basis that validation of AGW assumes and depends upon a long term warming trend over the time span as given by the IPCC, then its true validation and otherwise is only going to be demonstrated with the time span given. Thus we can't cherry pick short term annual or bi-annual comparisons amongst as emphatic evidence of validation. In the same way, the changes that ocuring with a raft of natural and cyclical forcings that are moving to a negative cycle - the potential effects of thse cannot equally be measured over annual or short term periods. In other words a level playing field in terms of measurement time should be adopted in terms of determining net outcome. That applies to the IPC/AGW as well as the potential effects of solar and cyclical feedbacks, which I still maintain are being underestimated and rather selectively overlooked in order to vaildate a man made theory.

The last century has shown that most of the actual warming that has occured has been cyclical - it remains to be seen how/if the assumed artifical man made positive warmth inducing feedbacks are going to have anywhere near the suggested impact to either increase further the rate of any warming, or just as likely (imo more likely) be able to reverse or offset any potential cooling from a raft of known (not assumed) negative natural/cyclical feedbacks.

It concerns me that we might be unpreapred for a much colder future as a result of unknown and (presently) unexpected effects rather than a warmer one. A colder future is a much more dangerous one and it would be unfortunately ironic if we placed so much faith in these assumptions of AGW that in a future generation we are totally unprepared for a much more harmful consequence because of so much being invested in a theory that cannot fail at any cost.

[VillagePlank]

That, VP, makes perfect sense to me: poor mixing being the main thing about the THC... :lol:

What is the 'residence time' for a newly-sunk water-salt mix???

I would say that it is dependant on the system itself, so it is dynamical - ie variable depending on the system parameters.

Also, thermal diffusivity (a measure of how something will adjust itself to it's surrounding temperature) is a=k/PC_p where k is thermal conductivity, P is density, and C_p is specific heat capacity. All other things being equal then (and density increasing) gives us this chart ...

And given that the reason why the THC exists is because the saltier the water is, the more dense it is. It is also the case that the saltier the water is, the less it will 'lose' it's heat. Hence, the reason for not mixing well being absolutely imperative to the LI.

[Admiral_Bobski]

It's worth pointing out that although the studies have shown the total heat content of the oceans continuing to rise, the measurements are down to about 2000m (Argo floats). The average depth of the oceans is 3800m (http://hypertextbook.com/facts/2006/HelenLi.shtml) - that leaves an awful lot of water which could be storing and releasing heat. I think you're right, sss, that this is an area that needs more study and until a complete analysis of the actual total heat content of the oceans is performed the "radiator" question is open to interpretation.

With regards the leaky integrator, I think it is spurious to ask what the mechanism for it is - there could well be various mechanisms all working in concert with one another, the oceans perhaps being just one of them.

CB

[sunny starry skies]

I would say - actually, hypothesize - that the heating of the ocean is the emergence of the excessively active sun over the last 50 years. ie the surface was warmed by the sun, ocean currents took some of that heat and buried it very very deep. A few years later, somewhere else along the THC conveyor (which, of course, is global) that current resurfaces. The point about poor mixing (probably due to massive densities that far under water) is critical.

My thoughts on ocean circulation is that if the heating was buried very very deep (presumably you're meaning below the 2km Iceberg suggested), it might take rather longer than 50 years to show up? ie hundreds of years? Also, I don't think it works to say 'buries it very deep, then released on resurfacing', as in most cases, once ocean water is buried deep, it is much cooler than air temperature on resurfacing (I think, also hypothesising here!), therefore will not be doing any delayed releasing of excess heat? Except in certain cases, namely Arctic/Antarctic regions in winter? It may, however, alter sea ice formation or convection processes in the surface-to-deep ocean which is another, altogether more complex solution. So long as we have a handle on the total heat content, then we can assess this point, but that's not all that easy a question to answer! I had a quick read of that Palaeoceanography paper - interesting one about the feedbacks required to explain the relative changes in ocean temperature and CO2, and how they are different between deglaciation (Co2, ice albedo, other forcing, maybe pH) and MIS3 (possibly southern high latitudes, different ratio of T/CO2), and testing it with the benthic forams. Are you suggesting that we would get a different ocean response to Sun conditions at present than in the past because of anthropogenic GHG, by using the different states and response rates in this paper as an analogue? My head hurts, it's complex! If so, that may be reasonable (the system operates in a different way with different initial conditions), but I'm still unsure as to why there should be such a lag, and then by extension, why the lag would be absent in the past (Maunder Minimum etc), rather than just different in length?

Apologies if I have this all backwards, but it's good to have a positive discussion on here rather than mud-slinging!

sss

[VillagePlank]

I'm asking for a mechanism to explain specific lengths of lag (LI of course?) else I'm going to be, cough, sceptical (not dismissive, sceptical - as I think I should be?).

The answer to that (ie how can we quantify how much, today, is 'lagged energy') comes from computer science and inventory analysis. You use either a FIFO, or LIFO pricing system.

Also, I don't think it works to say 'buries it very deep, then released on resurfacing', as in most cases, once ocean water is buried deep, it is much cooler than air temperature on resurfacing

Perhaps, but there is always somewhere on the planet that is winter, and therefore there is always somewhere on the planet where surface water temperature can radiate it's 0.5C difference between bloody freezing outside, and bloody freezing in. That paper is a core analysis of atmospheric CO2 and deep sea ocean temperatures; whilst, and I suspect you will forgive me this, this does enhance current consensus thinking on GhG, it also gives me a direct, and lagged link, between deep sea temperatures and atmospheric temperatures - and, if you consider CO₂ to be a proxy of temperature (Petite et al) then a relationship is there.

With regards the leaky integrator, I think it is spurious to ask what the mechanism for it is - there could well be various mechanisms all working in concert with one another, the oceans perhaps being just one of them.

Spot on!

Whilst the oceans are my favourite, clouds come along and plague my sleep from time to time. The idea is to find out the answer to a very simple question - does the Earth store sun activity and release it later? If so, what is the relationship?

Simple, huh?

:lol:

Edited February 9, 2010 by VillagePlank

[kold weather]

Well there obviously is some cyclical events that make a difference. For example once the Atlantic turns back into its negative phase your going to lose pretty much a whole basin of above normal waters and I suspect that got to make some difference, esp given most of the warm years also interestingly line up well with when the Atlantic was at its warmest, and equally lesser years like 2008 (though obviously still very warm!) have come when the Atlantic has been cooler then in recent years...as was the first few months of 09 before the El Nino helped to warm things back up again.

Saying that I find it highly likely that what will happen is we will stay stable for a little while yet before another big push occurs, probably when we enter the next warm phase after this one is done in the Atlantic and the PDO flips again...background warming will still occur but we probably won't get much above the record temps until that happens. So therefore the cooling that the global set-up would normally induce will only help to balance out the warming, though I suppose its not impossible at least for NW Europe and the Arctic region to our north to see a stronger response to the Atlantic phase switch which may lead to some cooling, maybe somewhat similar to 77-87 before another big leap upwards as we come towards the end of the next cold spell, whenever that will be.

However its all very interesting to observe!

[VillagePlank]

Anyway, what do you make of the graph here for example?

First curious and spurious observation is that the ocean heat looks like cumulative sum of a very active sunspot period. Need to do one hell of a lot of work to make that one stick, though! Thanks for the link, though - another $37.60 - for the ocean temperature paper.

Edited February 9, 2010 by VillagePlank

[Methuselah]

I would say that it is dependant on the system itself, so it is dynamical - ie variable depending on the system parameters.

Also, thermal diffusivity (a measure of how something will adjust itself to it's surrounding temperature) is a=k/PC_p where k is thermal conductivity, P is density, and C_p is specific heat capacity. All other things being equal then (and density increasing) gives us this chart ...

And given that the reason why the THC exists is because the saltier the water is, the more dense it is. It is also the case that the saltier the water is, the less it will 'lose' it's heat. Hence, the reason for not mixing well being absolutely imperative to the LI.

Thanks for that, VP. You explain that quite well...Whatever you do, don't lose faith with the LI. It may die a death, it may not; but it may - like Gould & Eldrige's 'Dynamic Equilibrium' theory in Evolution - become part of the mainstream (once the bickering has finished?)... :lol:

[sunny starry skies]

NSSC - a straight question: why do you believe there are feedbacks ignored by IPCC, METO and other climate forecasters?

I can see you believe it very strongly, but it's very hard to have a discussion with you when I don't have any information as to why you hold such a negative view on the state of the science? I'm (obviously) not going to change your view, but I would like to have the opportunity of understanding fully your viewpoint and how you come to hold it. I'm not ordering you to change your view (totally wrong thing to do on so many levels), but merely asking for some evidence to support your view. You don't have to provide the evidence, of course, as it is a free world, but it does mean I value your contribution to the climate change discussion rather less than someone (such as Dev, VP, C-Bob, Iceberg, TWS) who support their views with some supporting evidence. I'm sorry if that seems harsh to you, but questions of science surely require more than just opinion?

Oh, and you have me wrong on the -ve PDO influence: it has had an effect as I've said a number of times, to cause the slowing of temperature rise over the last decade. Which is why I wonder about the consequence of our first signifcant El Nino in 10 years. If you subtract ENSO/SOI, plus volcanic forcing, plus solar irradiation, plus aerosol effects from the 20th/21st Century temperature curve, what are you left with?

"The list that CB provided wrt to the METO suggests to me that the data used is selective in fitting the purpose. You can always get a confirmation bias result from a computer if you feed it selective data in order to validate a theory. But is it the right data when based on such assumptions?" Evidence for this selectivity would be nice? Do you think AGW theory is based on the results of a computer model, when it was first posited before computers came into wide use?

http://www.skeptical...mate-models.htm

Some nice graphs here - showing how in some cases, observed changes are in the lower range of model projections (surface temperature), and in other cases they are in the upper range or beyond the 'worst case' model projections (sea level and Arctic sea ice). Models are not perfect, and need constant refinement to a better understanding of the climate system, but to say they are useless, or to say that they are not taking into account key factors is not supported by any evidence I have seen, when global change is occurring within the bounds of predicted uncertainty levels.

Edit: And something else a good review of climate sensitivity estimates along with talk on feedbacks here (Knutti and Hegerl, 2008), and I think freely available:

http://www.iac.ethz....tti08natgeo.pdf

"Even the earliest estimates ranged remarkably close to our present estimate of a likely increase of between 2 and 4.5 °C (ref. 24). For example, Arrhenius[25] and

Callendar[26], in the years 1896 and 1938, respectively, estimated that a doubling of CO2 would result in a global temperature increase of 5.5 and 2 °C."

sss

Edited February 9, 2010 by sunny starry skies

[Gray-Wolf]

If we do have any waters locked away on deep sea conveyors that are carrying extra heat (the 'missing heat'?) then though they may emerge at lower than air temp they will be warmer than their 'non-warmed' counterparts and so chill less the air they contact.

We may find ourselves at a point where we are milding the world from 100yr old heat and from present day heat retention.

Sadly that would put us around 1910 for some of the re-surfacing deep water currents and we know that we were warming by this time. Are we about to have a 'natural cooling cycle' negated by todays GHG's and a century old heat source?

[VillagePlank]

We may find ourselves at a point where we are milding the world from 100yr old heat and from present day heat retention.

Ignoring, if I may, the physical mechanisms that underpin the LI, this idea is exactly why the LI predicts record maximum temperatures into some of the next ten years: we have had, during the 20th century, excessive solar activity for at least half of one century.

So, whilst the LI appears to corroborate the general consensus, it is derived from different source criteria. Furthermore, it may offer hope should we have a rebuilding of sea-ice extent, volcanic eruptions or a number of consecutive low solar maximums - this will allow this 'heat' to escape.

Edited February 10, 2010 by VillagePlank

[Gray-Wolf]

http://www.sciencedaily.com/releases/2010/02/100209100434.htm

Seems like our polluting fossil fuels may have a more immediate threat to offer us.

V.P., I hope you are right about sea ice re-build. As this season progresses and ice extent remains low I worry about the coming melt esp. in the light of our wrongly identifying sections of the 'melt resistant' perennial pack. If we accept that 09's max ice extent was exaggerated by winds spreading out the pack and ,had they compacted instead of spread, we'd have had less ice than 07' then we must worry about the potential for an average melt season this time.

If we melt out the average extent that we have the past 2 years then this low extent will lead to a record low ice extent (even with a similar spreading of the pack to last years).

[laserguy]

http://www.scienceda...00209100434.htm

Seems like our polluting fossil fuels may have a more immediate threat to offer us.

How much do they pay these geniuses? That's like saying stepping in front of a speeding bus is likely to result in personal injury. Where do I sign up?

[VillagePlank]

http://www.sciencedaily.com/releases/2010/02/100209100434.htm

V.P., I hope you are right about sea ice re-build. As this season progresses and ice extent remains low I worry about the coming melt esp. in the light of our wrongly identifying sections of the 'melt resistant' perennial pack. If we accept that 09's max ice extent was exaggerated by winds spreading out the pack and ,had they compacted instead of spread, we'd have had less ice than 07' then we must worry about the potential for an average melt season this time.

I haven't made any predictions about sea-ice build.

Edited February 10, 2010 by VillagePlank

[Gray-Wolf]

I haven't made any predictions about sea-ice build.

But it is on your 'wish list' of helpful factors is it not?As for popping the odd volcano, as long as they are on constructive plate margins and not over subduction zones eh? The last thing we need is a melt full of subducted carbonates reaching the surface .

Edited February 10, 2010 by Gray-Wolf

[VillagePlank]

<snip - not really relevant, here - will post somewhere else>

EDIT: Posted, here

Edited February 10, 2010 by VillagePlank

[sunny starry skies]

VP - bit of a 'leaky integrator' type of question for you, but I think relevant here. You're quite confident in your 'solar activity producing an oceanic lag' idea, as the mechanism by which the LI delays heat release. But... would you not expect these lags to be observable in the past, such as around the Maunder Minimum? I think that was what you were trying to get at with the paper yesterday, but I wondered if you could clarify. Why would there be a lag with 20th Century heating, yet the Maunder Minimum (and other solar minima) appear to occur on time for cool climatic events. It strikes me that I don't think you can have it both ways? I could understand slight differences in the lag time, but not presence/absence of a lag?

There is also the question of increased volcanic activity during phases of the Little Ice Age, which may, for example help explain why the late 18th Century is not obviously warmer, despite a pick-up in solar activity. How much did this increased volcanic activity contribute to the coolness of the LIA? Musings for the morning!

sss

[VillagePlank]

VP - bit of a 'leaky integrator' type of question for you, but I think relevant here. You're quite confident in your 'solar activity producing an oceanic lag' idea, as the mechanism by which the LI delays heat release. But... would you not expect these lags to be observable in the past, such as around the Maunder Minimum? I think that was what you were trying to get at with the paper yesterday, but I wondered if you could clarify. Why would there be a lag with 20th Century heating, yet the Maunder Minimum (and other solar minima) appear to occur on time for cool climatic events. It strikes me that I don't think you can have it both ways? I could understand slight differences in the lag time, but not presence/absence of a lag?

There is also the question of increased volcanic activity during phases of the Little Ice Age, which may, for example help explain why the late 18th Century is not obviously warmer, despite a pick-up in solar activity. How much did this increased volcanic activity contribute to the coolness of the LIA? Musings for the morning!

sss

I wouldn't say 'confident' It's just an idea that's floating around that I think has a little merit to it. As CB intimated, yesterday, this is actually a numbers game, and not one that can, with any certainty, posit any physical phenomena. If you take a peek over to the LI thread you can see what happens when you run the system backwards (actually, run it from an earlier starting point, since FIFO type systems cannot be 'run' backwards - well, perhaps they can but I've never found a good way of doing it)

Take a quick peek, here

Edited February 10, 2010 by VillagePlank

[sunny starry skies]

Something to think about... direct evidence for the existence and magnitude of the enhanced greenhouse effect:

http://ams.confex.co...aper_100737.htm

I don't know if everyone can pick up the .pdf or if it's restricted to academic sites, but the conclusion is:

"Measurements of the downward radiative flux have been made for several important greenhouse gases. At mid-latitudes in summer as compared to winter, our measurements show that the downward surface flux from H2O has doubled to 200 W/m2. The water increase causes a reduction of the fluxes from the other greenhouse gases. These measurements show that the greenhouse effect from trace gases in the atmosphere is real and adds significantly to the radiative burden of the atmosphere. The greenhouse radiation has increased by approximately 3.52 W/m2 since pre-industrial times.

This compares favorably with a modeled prediction of 2.55 W/m2. Measurements such as these can provide a means by which to verify the predictions made by global warming models (Puckrin et al; 2004)."

"this experimental data should effectively end the argument by skeptics that no experimental evidence exists for the connection between greenhouse gas increases in the atmosphere and global warming."

Strong stuff! Though I'm intersted that it hasn't been published in Nature, Science, or GRL - after all, the skeptics would have you believe that any old rubbish that supports the AGW view breezes through the peer-review process for the major journals. There does seem to several papers showing increased downward longwave radiation measured from the surface, combined with the satellite observations of a reduction in outgoing radiation necessarily meaning that the earth is getting warmer as a direct result of GHGs.

http://www.nature.co...s/410355a0.html

"Our results provide direct experimental evidence for a significant increase in the Earth's greenhouse effect that is consistent with concerns over radiative forcing of climate."

A good review and assessment in Huang and Ramswamy (2009) from the Journal of Climate, again may not be accessible to all though. They show that the changes in spectrum well exceed natural variability, as well as highlighting that spectrum measurements may be the best way of constraining the climate sensitivity problem (temperature impact of doubling CO2).

http://ams.allenpress.com/perlserv/?request=get-abstract&doi=10.1175%2F2009JCLI2874.1

This seems pretty good evidence not only that the mechanism works, but that the size of it is in line with what is expected.

I saw the Met Office is going for 2010 beating 1998 in mean temperature, and that it was spot on for its 2009 forecast (2000-2009 forecast errors average at 0.06C). It would seem odd that they have been so successful year-to-year if they are totally wrong about the driving mechanisms for global climate. This makes sense if the attribution studies' values are right for the level of significance of ENSO, GHGs, solar and volcanic. Only a major eruption or a big shift to La Nina seems likely to stop 2010 from breaking the record.

sss

Edited February 10, 2010 by sunny starry skies