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Discussion > (A)GW Lite

Comment?

Reference?

May 31, 2012 at 2:34 PM | Unregistered CommenterBBD

Logico

For an expert contrary view on the timing issue (among others) see:

http://www.seas.harvard.edu/climate/pdf/wunsch_2004.pdf

And for Wunsch's view on the relationship between obliquity, eccentricity and the ~82 - 123ka interglacial peak spacing, see Huybers & Wunsch (2005), emphasis added:

The 100,000-year timescale in the glacial/interglacial cycles of the late Pleistocene epoch (the past ~700,000 years) is commonly attributed to control by variations in the Earth's orbit1. This hypothesis has inspired models that depend on the Earth's obliquity (~ 40,000 yr; ~40 kyr), orbital eccentricity (~ 100 kyr) and precessional (~ 20 kyr) fluctuations2, 3, 4, 5, with the emphasis usually on eccentricity and precessional forcing. According to a contrasting hypothesis, the glacial cycles arise primarily because of random internal climate variability6, 7, 8. Taking these two perspectives together, there are currently more than thirty different models of the seven late-Pleistocene glacial cycles9. Here we present a statistical test of the orbital forcing hypothesis, focusing on the rapid deglaciation events known as terminations10, 11. According to our analysis, the null hypothesis that glacial terminations are independent of obliquity can be rejected at the 5% significance level, whereas the corresponding null hypotheses for eccentricity and precession cannot be rejected. The simplest inference consistent with the test results is that the ice sheets terminated every second or third obliquity cycle at times of high obliquity, similar to the original proposal by Milankovitch. We also present simple stochastic and deterministic models that describe the timing of the late-Pleistocene glacial terminations purely in terms of obliquity forcing.

Wunsch (2004) effectively sets out the null hypothesis. Then he moved on. Hubyers, it turns out, is an obliquity man ;-)

It's important to understand that the latest work (eg Shakun) is strongly supportive of Milankovitch theory, providing as it does an insight into the mechanisms by which changing insolation at high NH latitude comes to have global effects.

May 31, 2012 at 2:47 PM | Unregistered CommenterBBD

Logico

That entirely misses two points - the original point against Archer, that he considers melting rather than temperature change and this hides the fact that temp change leads CO2 change. I'm not generally outspoken, but he doesn't even hint at this, and I see that as bloody dishonest.

This is getting too close to 'sceptic logic' for my comfort. First, what reference are you using for the claim that *temperature* change leads CO2 change? Which proxies for T are considered, and over what geographical range? If you look carefully at Archer's Fig 8 (p 76) where sea level is used as a proxy for ice volume you can indeed see that CO2 rises before the major melt (inferred from SLR) gets under way (the grey vertical bars provide the reference). Not the clearest illustration I've ever seen, but absolutely not warranting the charge of 'bloody dishonest'.

This brings me to your repeated ad hominems against Hansen, and your use of terms such as 'failed' IPCC projection of C21st warming, 'the faithful', 'Green Religion', 'heretics' and so on. This is deeply off-putting and of course, wrong. The projections are for a warming *trend* over the C21st that accelerates around mid-century (under BAU conditions). Nobody ever said it would be monotonous, nor that natural variation would cease. That is a 'sceptical' misrepresentation and given that you say you've read AR4 WG1 I'm surprised to hear you make it.

I would be very grateful if we could stick to the scientific debate and avoid editorialising of this kind. It would also result in shorter comments - less work for both of us and anyone actually following this exchange.

May 31, 2012 at 3:21 PM | Unregistered CommenterBBD

Logico

There are so *many* things in your comments that I need to respond to :-)

You mention CO2 as a feedback for deglaciation in your final chunk, but (as your text indicates) that is an hypothesis comlete with its own suicide note - if the unbalanced heat is redistributed, the Milankovitch forcing disappears.

No! 'Redistribution' isn't the right conceptual frame. One needs to think in terms of amplifying feedbacks.

The collapse of the NH AMOC and consequent warming of tropical southern latitudes and eventually the Southern Ocean/Antarctic led to a rise in atmospheric levels of CO2. This globalised the effect and ice sheets begin to retreat at both poles and atmospheric CO2 levels start to rise as well (see this figure).

*Both* of these feedbacks are *positive* - that's to say they *amplify* the original orbital/obliquity forcing and of course the result is... more positive feedback. As discussed, this falls short of a runaway warming, but its enough to trigger (geologically speaking) rapid deglaciation and propel the climate system into an interglacial.

May 31, 2012 at 4:16 PM | Unregistered CommenterBBD

BBD:

I had written: "I can imagine the IPCC faithful looking at a guitar string or a pendulum and trying to assign some 'external forcing' to account for its movement, now to the left, now to the right."

You replied: "This is... misleading. A pendulum... is impelled by an external forcing (energy input). This may be a simple manual push..." That's right - there is an energy input into the system. There is an energy input into the climate system. That does not imply in either case that variation requires further "external forcing".

I had witten: "Really, the 'inconvenient data chucked away' is the cooling itself, 30 or 40 years' worth; and you have done it, too. You gave 4 curves (May 25, 9:45 AM) to prove that warming had accelerated in the late 20th century. That was achieved by ignoring the midcentury cooling."

You replied: "Not at all. The whole point of using a third order polynomial is that it *doesn't* 'chuck away' data. It is the best fit for the time-series as a whole." Not so. The mid-century cooling is a significant event that is not recoverable from the curves.

I had said that a break in a car journey would similarly be lost in a speed-time graph, and could produce instead a false "acceleration". (Leads naturally into a discussion about the claims that the early 21st century flatline means even faster warming is being stored in the system. Sauce for the gander: presumably the 1980 - 1998 warming was largely made up of stored warming from the previous 30 or 40 years, thus reducing the real rate of warming by more than half.)

You replied: "...the most recent warming is shown to have been more rapid than the 1910 - 1940 episode." Insignificantly (and see the above excursus). (Leads naturally to a discussion of Hadcrut 3 and 4. Generally warmer in the revised version EXCEPT at the key points around 1940 and 1980 - look closely and you will see how an insignificantly faster warming in 1910 - 1940 vis-a-vis 1980 onwards has been reversed; very convenient headline for the next IPCC Assessment Report no doubt: "All of the global temperature records agree that the fastest etc." Lucky or what...)

"I know you don't mean to be offensive, but the one thing that does anger me particularly is any suggestion of graph-cooking. I leave that to others." You still haven't caught on to the thrust of the "sine wave" remarks in this thread. Do you honestly believe that a straight line along the x-axis would not be throwing away data?

You ask for a reference re the 80W/sqm convected past the GHG's. (On the Earth Energy Budget diagrams it often appears as 79W.) "Evaporation of water at the ocean surface cools the ocean. The resulting water vapour rises in air columns to great heights, carrying latent energy with it. The latent energy is released into heat when the vapour condenses into ice crystals, which it generally does at heights above the radiation traps. The latent heat is then radiated freely into space. This bypassing of the traps is by no means complete, but it has the effect of reducing their blocking ability from the previous 63 per cent back to about 40 per cent." (F. Hoyle, 1981) That's about 1/3. Without that negative feedback we'd be a few tens of degrees hotter, I guess.

I had witten: "For an expert contrary view on the timing issue (among others) see: http://www.seas.harvard.edu/climate/pdf/wunsch_2004.pdf "

You replied: "And for Wunsch's view on the relationship between obliquity, eccentricity and the ~82 - 123ka interglacial peak spacing, see Huybers & Wunsch (2005)..."

I've read it. H and W concluded: "The simplest interpretation of our results is that during the Pleistocene epoch, the Earth tends to a glacial state (anthropogenic influences aside) and deglaciates NEAR some, but NOT all, obliquity maxima. Obliquity TIMING of deglaciation, probably in concert with STOCHASTIC FORCING..." (Emphasis mine) My original point was that he Milankovitch Effect was inadequate to force glaciation. According to this paper, it doesn't even trigger glaciation. It allegedly triggers deglaciation in a system of stochastic forcing - internal variation. If major fluctuations can be triggered by the tiny Milankovitch imbalance (that's still an if) how much more easily might they be triggered by PDO/ENSO events? There's no comfort there for the CAGW camp.

But there are many who doubt Milankovitch in the CAGW fold. Another good example would be Richard A. Muller. Nevertheless, the Milankovitch Theory has been regarded as definitive since Hays et al, 1976 - an example of the yearning for certainty in science. (See later my Julian Jaynes quote.)

I had written: "That entirely misses... the original point against Archer, that he considers melting rather than temperature change and this hides the fact that temp change leads CO2 change. I'm not generally outspoken, but he doesn't even hint at this, and I see that as bloody dishonest."

You replied: "This is getting too close to 'sceptic logic' for my comfort. First, what reference are you using for the claim that *temperature* change leads CO2 change?" Fischer et al 1999 and Caillon et al 2003. Both use ice cores so the temps are Antarctic. Both find that CO2 lags temp change by several hundred years. This is well known to CAGW people. The lack of relationship is visible on longer timescales, e.g. throughout the Mesozoic and Cenozoic. I thought everybody knew that.

"This brings me to your repeated ad hominems against Hansen..." I judge as I see. His statements are, and always have been, far more extreme than the IPCC consensus. He expresses no uncertainty, as in the heatwave quote I gave. Also:

http://www.guardian.co.uk/commentisfree/2009/feb/15/james-hansen-power-plants-coal

You objected to: "...your use of terms such as 'failed' IPCC projection of C21st warming..." The projections all showed, even at the low edge of uncertainty, a clear increase. They have failed to include the actual pattern of the past 12 years even as an outlier. See, too, my remarks above about "stored up" heating.

You objected to my using terms like: "...the faithful... Green Religion... heretics..." You say: "This is deeply off-putting..." Well, I don't use those terms lightly. This is my philosophical position concerning CAGW:

“These scientisms, as I shall call them, are clusters of scientific ideas which come together and almost surprise themselves into creeds of belief, scientific mythologies…. And they share with religions many of their most obvious characteristics: a rational splendor that explains everything, a charismatic leader or succession of leaders who are highly visible and beyond criticism, certain gestures of idea and rituals of interpretation, and a requirement of total commitment. In return the adherent receives what the religions had once given him more universally: a world view, a hierarchy of importances, and an auguring place where he may find out what to do and think, in short, a total explanation of man. And this totality is obtained not by actually explaining everything, but by an encasement of its activity, a severe and absolute restriction of attention, such that everything that is not explained is not in view.”
(Julian Jaynes, "The Origin of Consciousness in the Breakdown of the Bicameral Mind", 1976)

I'm well aware that many AGW sceptics are True Believers of a different religion, and treat Climategate as an Auto da Fe. There's a lot of it about.

May 31, 2012 at 11:16 PM | Unregistered Commenterlogicophilosophicus

I'm well aware that many AGW sceptics are True Believers of a different religion, and treat Climategate as an Auto da Fe. There's a lot of it about.

May 31, 2012 at 11:16 PM | logicophilosophicus>>>>>

I realize you're probably trying to live up to your rather pretentious pseudonym, but what has this metaphysical mumbo jumbo got to do with physics?

Perhaps you really need to communicate with like minded individuals on one of those navel gazing philosophy blogs.

"I'm well aware that many AGW sceptics are True Believers of a different religion, and treat Climategate as an Auto da Fe. There's a lot of it about."

That's a pretty weird statement - What on earth does it mean? - How are you aware of it it? - Or is it merely a personal opinion based on your own prejudices [which, from a previous post, confuse qualified engineers whose task is the application of science, with odd job men who do all their calculations on the back of envelopes - your words]

Engineers, and to some extent scientists, tend to be creative people, as opposed to those who class themselves as philosophers - whose personal opinions frequently end up with death and destruction of millions in order to suit the ego of the one.

Jun 1, 2012 at 9:17 AM | Unregistered CommenterRKS

Here we go again.

The word "philosophy" certainly rattles your chain. I can, however, reassure you that I have never brought about "the death and destruction of millions".

Another philosopher (with whose views on very many other issues I disagree) said:

“There's nothing I like less than bad arguments for a view I hold dear.” (Daniel Dennett)

It is when their fervour for an entrenched position ignores the truth, or endorses a lie, and their "severe and absolute restriction of attention, such that everything that is not explained is not in view" (in idiot-speak, "tunnel vision") becomes a matter of "total commitment", that the supposed "science" some sceptics brag of is actually "scientism" in Jaynes's sense, and they are no different in their intellectual processes than religious fundamentalists.

Here is an example from another thread, one piece of evidence for my statement about the existence of True Believers in the sceptical camp.


RKS: "I'm still waiting to hear what percentage of surface radiation would be 'back radiated' by 0.039% of the atmosphere [bit of a big gap between molecules] assuming that instead of an emissivity of around 0.01 [an unrealistic maximum] that the emissivity of this gas was actually ONE. - And also assuming [again unrealistically] that ALL emitted radiation was back to the surface."

Me: "Virtually all the radiation in the CO2 absorption band is absorbed in the lower atmosphere. Most is reradiated away from the earth, of course, let's say x%. It is immediately reabsorbed and reemitted, so now (crudely) x% of x% is heading skywards. That happens many, many times, and x/100 raised to a high power is miniscule."

RKS: "A few x's here and there are just mind games. When an engineer makes use of physics there can be no cause for error, all physical properties must be fully quantified in order to be used as a tool - They deal with the real world and leave mind games to the academics."

Me: "Those little x's, or the approximation "opaque", are exactly the kind of back-of-an-envelope arguments I usually get from [proper] engineers. Challenging standard physical theory... is more characteristic of flat earthers and - more worryingly - gives CAGW sceptics a bad name."

RKS: "If you are scynical of the position of the IPCC and wish to discuss climate, why not grow a pair instead of not wanting to look silly by challenging the CO2 hypothesis..."

You claim that I described "qualified engineers" as "odd job men who do all their calculations on the backs of envelopes - your words."

[snip. Calm down, please. BH]

Jun 1, 2012 at 4:31 PM | Unregistered Commenterlogicophilosophicus

Logico

Very busty today - will respond to your last this evening.

Jun 1, 2012 at 5:55 PM | Unregistered CommenterBBD

I too have a glamorous woman who makes demands on my time.

Jun 1, 2012 at 6:03 PM | Unregistered Commenterlogicophilosophicus

Logico

The lack of relationship [between CO2 and T] is visible on longer timescales, e.g. throughout the Mesozoic and Cenozoic. I thought everybody knew that.

It would seem not :-) . Hansen & Sato (2012) Paleoclimate implications for human-made climate change (in press) demonstrates a clear and robust relationship between CO2 and T across the Cenozoic (emphasis added):

HS12 Fig 1.

Solar luminosity is increasing on long time scales, as our sun is at an early stage of solar evolution, "burning" hydrogen, forming helium by nuclear fusion, slowly getting brighter. The sun's brightness increased steadily through the Cenozoic, by about 0.4 percent according to solar physics models (Sackmann et al., 1993). Because Earth absorbs about 240 W/m2 of solar energy, the 0.4 percent increase is a forcing of about 1 W/m2. This small linear increase of forcing, by itself, would have caused a modest global warming through the Cenozoic Era.

Continent locations affect Earth's energy balance, as ocean and continent albedos differ. However, most continents were near their present latitudes by the early Cenozoic (Blakey, 2008; Fig. S9 of Hansen et al., 2008). Cloud and atmosphere shielding limit the effect of surface albedo change (Hansen et al., 2005), so this surface climate forcing did not exceed about 1 W/m2.

In contrast, atmospheric CO2 during the Cenozoic changed from about 1000 ppm in the early Cenozoic (Beerling and Royer, 2011) to as small as 170 ppm during recent ice ages (Luthi et al., 2008). The resulting climate forcing, which can be computed accurately for this CO2 range using formulae in Table 1 of Hansen et al. (2000), exceeds 10 W/m2. CO2 was clearly the dominant climate forcing in the Cenozoic.

For a really deep time perspective, see Royer et al. (2004) CO2 as a primary driver of Phanerozoic climate:

Recent studies have purported to show a closer correspondence between reconstructed Phanerozoic records of cosmic ray flux and temperature than between CO2 and temperature. The role of the greenhouse gas CO2 in controlling global temperatures has therefore been questioned. Here we review the geologic records of CO2 and glaciations and find that CO2 was low (<500 ppm) during periods of long-lived and widespread continental glaciations and high (>1000 ppm) during other, warmer periods. The CO2 record is likely robust because independent proxy records are highly correlated with CO2 predictions from geochemical models. The Phanerozoic sea surface temperature record as inferred from shallow marine carbonate δ18O values has been used to quantitatively test the importance of potential climate forcings, but it fails several first-order tests relative to more well-established paleoclimatic indicators: both the early Paleozoic and Mesozoic are calculated to have been too cold for too long. We explore the possible influence of seawater pH on the δ18O record and find that a pH-corrected record matches the glacial record much better. Periodic fluctuations in the cosmic ray flux may be of some climatic significance, but are likely of secondorder importance on a multimillion-year timescale.

Jun 1, 2012 at 7:42 PM | Unregistered CommenterBBD

Mrs BBD is a handsome creature and trop belle pour moi in the view of some, but sadly, it was just bloody work chewing up the hours today.

Jun 1, 2012 at 7:48 PM | Unregistered CommenterBBD

Logico

That's right - there is an energy input into the system. There is an energy input into the climate system. That does not imply in either case that variation requires further "external forcing"

One has to ask why GAT, OHC and SST are all trending up. How do we account for the energy necessary to heat the entire climate system over a period of many decades? Natural variation is just wiggles (see Foster & Rahmstorf 2011). When F&R removed the effects of ENSO, solar variation and volcanism they revealed the underlying trend. The parsimonious explanation for this otherwise inexplicable accumulation of energy in the climate system is increased RF from GHGs.

I'll try to respond to the main points in your Jun 1, 2012 at 4:31 PM over the course of the evening - sorry for the piecemeal format :-)

Jun 1, 2012 at 8:35 PM | Unregistered CommenterBBD

cont...

Sauce for the gander: presumably the 1980 - 1998 warming was largely made up of stored warming from the previous 30 or 40 years, thus reducing the real rate of warming by more
than half.)

Why? You assume a constant forcing over the entire period but this was not the case. The forcing has *increased* steadily. Anyway, if the energetic reservoir was the ocean (and where else could it be?), we'd expect to see a reduction in OHC 1980 - 1998. But apart from the 1981 -1983 dip OHC rose (note, strong El Nino 1982 - 83; El Chicon April 1982). So why did the troposphere warm and why did the ocean warm?

I'm not asking your for an answer here, simply to think about what the observations suggest vs your line of argument.

Jun 1, 2012 at 8:54 PM | Unregistered CommenterBBD

(F. Hoyle, 1981)

Ah. Your position wrt WV is based on an incorrect analysis by a non-climatologist in 1981 a little long in the tooth ;-)

Have a look at Trenberth et al. (2008) Earth's global energy budget for a current overview.

Jun 1, 2012 at 9:09 PM | Unregistered CommenterBBD

Logico

Incidentally, if you want to highlight quotes it's easily done. Just format as follows, replacing the conventional brackets with < >

(blockquote)Quoted text here.(/blockquote)

I do find it makes comments easier to follow, but of course this is simply a suggestion - please don't be offended as no criticism is implicit.

Jun 1, 2012 at 9:22 PM | Unregistered CommenterBBD

Logico

Oh dear. I've only now spotted that typo. It all makes more sense now :-) Sorry, it's been a long day.

My original point was that he Milankovitch Effect was inadequate to force glaciation. According to this paper, it doesn't even trigger glaciation. It allegedly triggers deglaciation in a system of stochastic forcing - internal variation.

This is contradictory, and anyway not what WH05 is saying. Its main conclusion is that a combination of eccentricity and high obliquity triggers deglaciations, just as Milankovitch originally proposed:

The simplest inference consistent with the test results is that the ice sheets terminated every second or third obliquity cycle at times of high obliquity, similar to the original proposal by Milankovitch.

Wunsch's adherence to the minority position that a hypothetical stochastic 'forcing' has some role to play in initiating deglaciation is his right, but it doesn't mean he is right :-). It is also fair comment to say that WS05 as a whole supports the standard position.

Evidence that Milankovitch forcing is the cause of glacial terminations is continuing to emerge, eg Shakun et al. The stochastic argument remains hypothetical and its actual physical mechanisms are elusive. The mysteries are far from solved, of course, but Milankovitch remains the most plausible explanation on the table.

Jun 1, 2012 at 11:39 PM | Unregistered CommenterBBD

It is also fair comment to say that WS05 as a whole supports the standard position.

Eh. Not my night. 'WS05' = Huybers & Wunsch (2005).

If I'm not careful, They will take me off the payroll.

:-)

Jun 2, 2012 at 12:42 AM | Unregistered CommenterBBD


[Snip: calm down please.BH]

Jun 2, 2012 at 2:13 AM | Unregistered CommenterRKS

[Snip: calm down please.BH]

Jun 2, 2012 at 2:13 AM | RKS>>>>>

And this personally offensive post directed at me containing untrue statements I am supposed to have made?

Jun 1, 2012 at 4:31 PM | logicophilosophicus

The guy is an AGW advocate who insults those who disagree with his propaganda!!

Jun 2, 2012 at 9:04 AM | Unregistered CommenterRKS

Mate, he said calm down.

Jun 2, 2012 at 9:52 AM | Unregistered Commentersplitpin

Mate, he said calm down.

Jun 2, 2012 at 9:52 AM | splitpin>>>>>

Firstly, I was addressing BH and secondly, I expect even handedness.

Jun 2, 2012 at 9:56 AM | Unregistered CommenterRKS

Logico

You still haven't caught on to the thrust of the "sine wave" remarks in this thread.Do you honestly believe that a straight line along the x-axis would not be throwing away data?

Internal variability produces 'wiggles' (see actual boffin use this term below) which average out over time. Internal variability can't produce a trend over longer periods because of conservation of energy.

Here's Kyle Swanson, co-author of a somewhat misunderstood study (Swanson & Tsionis 2009) discussing the conundrum at RC:

It first needs to be emphasized that natural variability and radiatively forced warming are not competing in some no-holds barred scientific smack down as explanations for the behavior of the global mean temperature over the past century. Both certainly played a role in the evolution of the temperature trajectory over the 20th century, and significant issues remain to be resolved about their relative importance. However, the salient point, one that is oftentimes not clear in arguments about variability in the climate system, is that all else being equal, climate variability and climate sensitivity are flip sides of the same coin. (see also the post Natural Variability and Climate Sensitivity)

A climate that is highly sensitive to radiative forcing (i.e., responds very strongly to increasing greenhouse gas forcing) by definition will be unable to quickly dissipate global mean temperature anomalies arising from either purely natural dynamical processes or stochastic radiative forcing, and hence will have significant internal variability. The opposite also holds. It’s painfully easy to paint oneself logically into a corner by arguing that either (i) vigorous natural variability caused 20th century climate change, but the climate is insensitive to radiative forcing by greenhouse gases; or (ii) the climate is very sensitive to greenhouse gases, but we still are able to attribute details of inter-decadal wiggles in the global mean temperature to a specific forcing cause. Of course, both could be wrong if the climate is not behaving as a linear forced (stochastic + GHG) system.

If you follow the link, note the last paragraph of Swanson's article.

Jun 2, 2012 at 11:51 PM | Unregistered CommenterBBD

BBD

Thanks for your considered replies. I will try to explain why they do not affect my position.

Firstly, note that I am not committed to any particular mechanism, but I am concerned that latent heat transport as a changing feedback is never apparaently discussed.

You assume that my Fred Hoyle reference indicates that Hoyle is the originator of his account of the greenhouse effect and bypassing of the GHG trap. Actually he claims it is general climatological knowledge (albeit third of a century ago) but gives no reference. I had read as a child the article on the Radiative Balance of he Earth in Encyclopedia Britannica, and it stuck with me. I still have the set (1947 edition) and checked today - the specialist author is "H. Wr." who - infuriatingly - is omitted from he list of authors' full names. Anyway, same mechanism, slightly different numbers. Once read, it was so obvious. Energy (of appropriate wavelength) radiated from the earth's surface can't get out because the H2O vapour absorbs and reradiates again and again until the radiation reaches the surface again. Treating the atmosphere as N shells, where N is very large, makes that obvious. But radiation up wjere the H2O condenses/freezes out is by definition above most of the atmospheric water vapour. By the same N shells argument, It can't get in. It is reradiated fairly swiftly into space.

Trenberth's paper isn't very specific about this. If you look at his diagram, you'll see that the band representing radiated energy from the surface reaches much higher into the atmosphere than the band representing the 80W/sqm of latent heat. That's the wrong way round, and is very misleading.

As you can see, I don't rely on sufficient hidden reservoirs of energy to heat the earth. The energy all comes from the sun; but I do think that sufficient sources of energy exist to affect the latent heat transport mechanism (for example the levels at which the sea partitions its heat energy), or to provide far greater and swifter hemispheric imbalances than the Milankovitch effect (e.g. the raising of the Himalayan mountains by tectonic activity, which creates the conditions for a reflctive ice cap etc).

Wunsch's view on Mlankovitch may be unorthox, as is Richard A. Muller's, and others who cannot accept that a small imbalance between the hemispheres has a major and often rapid effect. At best it may, sometimes, contribute to triggering change. My point was exactly that - that there are climate experts (I deliberately cited "warmists" here) who doubt the adequacy of the Milankovitch effect.

This links with your concern that sufficient reservoirs of energy to power internal variation may be hard to find; but I've already stated my position.

Re CO2 and temp, I gave the icebore references (multicentury lag). I also mentioned mesozoic-cenozoic. It's not crucial if I'm mistaken, of course, but I had just been looking at the graph here:

http://deforestation.geologist-1011.net/

and noticed the poor relationship. The paper you cite is Hansen... You may not see this, but many CAGW writers show various levels of confirmation bias. (Remember this - to which you did not respond:
"As for the heatwaves, Hansen has just demonstrated the reality of this claim empirically. See Hansen et al. (2012)" I replied, "Thanks. I downloaded this. I haven't read it yet, but I was expecting to find Hansen's explanation of how AGW impacts on blocking highs and the jet stream. So I did a search in this paper for "blocking high" - no result. "Jet stream"? No result.) Hansen's certainty on current catastrophic effects (definitely not a "consensus" view) are an example. So I read the paper carefully, and I note that temp and CO2 do not appear on the same graph. The detailed comparison is not easy to make.

BTW did I give you this embarrassing Hansen effort - probably more disgraceful than the "death trains" and, again, saturated with the new Original Sin of CO2 emission:

http://www.vancouverobserver.com/blogs/climatesnapshot/2012/05/15/global-warming-increasing-400000-atomic-bombs-every-day

Oh yes, you thought I was insisting on "constant forcing" but I hope you can see that is not the case.

I have enjoyed the discussion. I think you have sometimes ignored certain points I've made, but in all honesty even those ppints you chose to address still stand, I think. Anyway, you can look back over the thread at your leisure. I shall be reading your sources very carefully, for which much thanks.

[I won't be posting here again. There's a certain amount of nastiness which I can always ignore or handle, but I don't like fair comment being snipped. That's the first time I've been snipped since my vasectomy (didn't much like that either) and it makes me look like the primary offender when I get the first snip.]

Jun 3, 2012 at 12:09 AM | Unregistered Commenterlogicophilosophicus

Logico

I'm on my way to bed, so proper response tomorrow. One thing though. BH is pretty fair. Perhaps you could write it off as collateral damage? It's happened to me here once or twice but I've lived to tell the tale.

:-)

Jun 3, 2012 at 12:43 AM | Unregistered CommenterBBD

Is this pseudish nonsense contributing anything useful at all to the AGW debate? Hell no!! Note that the topic maker wisely dropped out long ago. You are far from the smartest tool in the shed, BBD, and logico is very unwise to try to outdo the juvenility of your arch senior common room sneers.

Just so I make myself perfectly clear:

'In modern usage, sophism, sophist and sophistry are used derogatively.

A sophism is taken as a specious argument used for deception. It might be crafted to appear logical while actually representing a falsehood, or it might use obscure words and complicated sentence constructions in order to intimidate the opponent into agreement out of fear of feeling foolish. Other techniques include manipulating the opponent's prejudices and emotions to overcome their logical faculties.' (Wikipedia)

Tell me how that doesn't sum the two of you up perfectly, or better still, don't. Bloviation is an extremely unattractive habit.

Jun 3, 2012 at 7:55 AM | Unregistered CommenterChris M