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Discussion > So where are Salby and Darwall wrong .... precisely?

RadicalRodent asks "how CO2 could be such a greenhouse gas as claimed, it being such a tiny proportion of the atmosphere" if you want to know the scientific argument, I would recomment Raymond Pierrehumbert's book on "The Principles of Planetary Climate" as a good starting point. The basic mechanism was first clearly elicidated back in the 50s and 60s by Gilbert Plass, his papers are available online somewhere IIRC.

If you want an intuitive answer, I would say that the amount of energy the Sun transfers to the Earth is vast, but so is the amount that the Earth reflects and re-radiates back into space (indeed for global temperatures to stay stable, the two must be very evenly balanced). A small change in the proportion of this energy that is re-radiated is itself a very large amount of energy, and hence can have a significant effect on global temperatures. To put it more concisely, the reason such a small amount of CO2 to have such a large effect is because it modulates a vast flux of energy.

I am interested in science, I am not interested in blog-wars, so I am not going to be drawn into a discussion of that. The question was "So where are Salby and Darwall wrong .... precisely?", I have answered that, by pointing out that there is no mathematical connection whatsoever between the correlation Salby observes and the long term increase in CO2, and that Salby was unaware of the existing work that already explains the correlation. Lets discuss that.

Aug 21, 2014 at 12:38 PM | Unregistered CommenterGavin Cawley

Gavin, try reading what I write. I did not state or even infer that deep-sea vents were a source of CO2; I said that they were a source of acidification of the water. What the acid is, I did not state, as I do not know. The reason I mention that life still thrived is that one of the alarms of AGW is the threat to life – I was merely pointing out that, in what many would consider an extraordinarily hostile environment (highly acidic, in the otherwise very alkaline world of the oceans), life can thrive. While you might consider that irrelevant, I do not.

Similarly, no-one has yet managed to answer my question as to quite how CO2 is the cause of AGW claimed for it, they just get objectionable.

Is CO2 the only gas involved in Henry’s Law? I suspect not, so the ratios of gasses dissolving or not in the oceans will be more or less as they are now; as CO2 is just 0.04% of the gasses likely to be dissolved (or not) in the oceans, we are not talking about a huge quantity in the scale of things, here.

Now, you resort, once more, to the rise in CO2 being primarily anthropogenic (with little evidence to support this); why are the CO2 levels observed higher over the rainforests than over urban areas? Is CO2 being drawn to all those trees? I have seen many sources where the proportion of human-generated CO2 is about 3-5% of the total rise; why are so many insisting that the figure is the inverse? Is someone lying, or otherwise deliberately misleading?

For example, you've stated more than once that CO2 levels were around 4000 ppm during the last ice (20000 years ago or so). You've been somewhat dismissive of those who can't find this out easily. However, you are very clearly wrong. Have you acknowledge this error yet?
I might be in error, but do not think so. I cannot remember where I have seen those figures, but it was on more than one site, and, to tell the truth, can’t be bothered looking for them again. I am dismissive of those who cannot find it as I feel that, if I can find it, then it cannot be too difficult to find.

Aug 21, 2014 at 12:53 PM | Registered CommenterRadical Rodent

Gavin Cawley's temperate and well-referenced comment (Aug 21, 2014 at 9:44 AM) is a very welcome one, although I baulk at having to pay $35 to read one of his papers which he links to. The abstract though is quite informative, and it looks like in his paper he has been able to strengthen the case that most, perhaps all of the rise in ambient CO2 is due to our disturbances, most especially our burning of fossil-fuel. This does seem to me to be the most plausible of explanations, given the magnitude of estimated emissions being well in excess of that required to explain the observed rise.

But yet, there remain grounds for further discussion of this. The fact that uncertainties in the sizes, and fluxes, of various natural sources and sinks are way larger (as I recall off the top of my head) than the estimated human contribution each year gives pause by itself. The top of my head also tells me that out-gassing estimates associated with rising sea surface temperatures are too small in the short-term to account for the observed rises in ambient CO2, so that may not be a sufficient alternative explanation. On the other hand, we do not know where all our CO2 goes. About half is presumed to stay airborne, about half is absorbed presumably at the surface. My sometimes-trustworthy head-top recalls that about half of that half can be accounted for, leaving a missing sink to be found for the rest.

Salby looks at this from a different perspective, by examining temporal sequences of ambient CO2 and temperatures. He finds, as does Humlum in a separate investigation, that the temperature variations precede the CO2 variations over quite short timescales. This is intriguing to say the least, and seems well worthy of ongoing discussion when the core issue at stake is to tease out cause and effect in a complex system. In this context, I note also that Jan Veizer, makes interesting points as a proponent of the notion that the water cycle is far, far more important than the carbon cycle in influencing climate, e.g. Thus the carbon cycle is not driving the water cycle, but is “piggybacking” on it.

If I were ruling the world, or at least say the UK's budget, I would happily replace a chunk of state spending on renewables with funding for detailed observational research into the water cycle over scales of days to hundreds of years, with a little chunk allocated also for the carbon cycle in view of its political importance. The recent paper from the Netherlands discussed on this blog here reveals both how hard it is to get good data on airborne CO2, and how little we know about it. Improving that knowledge would be a higher priority for me than further spending, for example, on super-computers for GCMs. Nullius in Verba made this observation (Jul 21, 2014 at 9:14 PM ) in the comment thread on the Netherlands paper:


Similarly, you can't tell what's causing the rise in CO2 just by doing an isotopic analysis, measuring how much of the CO2 in the air at any one time was once fossil fuel. Most of it isn't, and what there is would be there anyway. The only way you can know is to understand what controls all the other flows, and how they are affected by overall level.
The long-term rise is very likely anthropogenic in my opinion, on the basis that nobody has offered any solid evidence for another mechanism (and Occam's Razor), but proving it is more difficult than the standard story would suggest.

That seems about right to me.

I hope we shall hear a lot more from Prof Salby, although the astonishingly vindictive treatment he has been subjected to by his university (see the Darwall article for details) is scarcely going to be conducive to scholarly work. In particular, it would be interesting to see exploration of overlaps between his work and that of Veizer on the primacy of the water cycle . For some background on vindictive reactions to some of Veizer's work, see: http://notrickszone.com/2013/12/17/climate-scientist-blasts-ruthless-dangerous-and-dictatorial-german-climate-science-bullies-and-silences-dissent/. We are living in interesting times, and they are quite stressful for anyone trying to make sense of the climate system without merely accepting the 'authority' of such as the IPCC movers and shakers. Minds are made up. Positions are entrenched. And money flows like water to protect them.

Aug 21, 2014 at 1:02 PM | Registered CommenterJohn Shade

You wont find anyone who (...) claims that CO2 is the only "control knob" (apart from some in the skeptic camp who one might expect to know better). ...
Aug 21, 2014 at 10:47 AM Raff

Raff - Sandy S said "...those who think CO2 is the main (only) climatic control knob ". My impression is that there are very few 'climate scientists' who do *not* believe it is the main climate control knob.

You give the impression of making stuff up on the fly.

Atmospheric CO2: Principal Control Knob Governing Earth’s Temperature
Andrew A. Lacis*,
Gavin A. Schmidt,
David Rind,
Reto A. Ruedy
Science 15 October 2010:
Vol. 330 no. 6002 pp. 356-359

The role of long-lived greenhouse gases as principal LW
control knob that governs the global surface temperature

for past and future climate change
ByANDREW A. LACIS*, JAMES E. HANSEN, GARY L. RUSSELL, VALDAR OINAS and
JEFFREY JONAS, NASA Goddard Institute for Space Studies, 2880 Broadway, New York,
NY 10025, USA

Quote: "...This leaves atmospheric CO2 as the effective control knob driving the current global warming trend...."

Aug 21, 2014 at 1:06 PM | Registered CommenterMartin A

Radical,
I think you may be directing things at Gavin when meaning me (sometimes at least). I'll make one final comment. I do really wish that we could have serious discussions about this topic and I appreciate that what I'm about to say may annoy you, but maybe you can think about it a little, at least.

You said,


I might be in error, but do not think so. I cannot remember where I have seen those figures, but it was on more than one site, and, to tell the truth, can’t be bothered looking for them again. I am dismissive of those who cannot find it as I feel that, if I can find it, then it cannot be too difficult to find.

I have looked. I can't find it. I find hoards of evidence that 22000 years ago CO2 levels were around 180ppm not 4000ppm. I also find hoards of evidence to suggest that it hasn't exceeded 300ppm (until this last century) for over a million years. So, you've made a statement that everything I've found suggests is wrong. You, however, choose to not back this up and simply claim that others should be able to find it since you managed to do so. You simply say "so what, I saw it, I can't be bothered to look again". That's fine, but maybe consider this when you criticise what happens on SkS. I also have no real sense of why you won't check and acknowledge your error, assuming you discover yourself to be wrong (as you probably will). It's no big deal and I certainly won't crow about it if you did. I'd be quite impressed, to be honest.

Aug 21, 2014 at 1:10 PM | Unregistered CommenterAnd Then There's Physics

Gavin Cawley's temperate and well-referenced comment (Aug 21, 2014 at 9:44 AM) is a very welcome one, although I baulk at having to pay $35 to read one of his papers which he links to.
Aug 21, 2014 at 1:02 PM | Registered CommenterJohn Shade

Gavin Cawley let me have his paper a year or two ago. I'd imagine he'd let you have it if requested.

We had some interesting discussion and I was able to reproduce his calculations. Our discussion broke off (I got sidetracked with some things that demanded attention - and still do) when we were discussing whether or not his differential equation was linear - maybe at some point it will be possible to continue the discussion.

I'd compliment Gavin on his invariable courtesy and measured comments.

Aug 21, 2014 at 1:13 PM | Registered CommenterMartin A

RadicalRodent wrote "Gavin, try reading what I write. I did not state or even infer that deep-sea vents were a source of CO2;"

fair enough, I accept that point. However they are still a small source of acidity, even compared to anthropogenic emissions (which would need to include suplhates etc. if other forms of acidity from deep-sea vents are included).

"Similarly, no-one has yet managed to answer my question as to quite how CO2 is the cause of AGW claimed for it, they just get objectionable."

I have attempted to do so in my previous post.

"Is CO2 the only gas involved in Henry’s Law?"

no, Henry's law applies independently to all soluble gasses.

"so the ratios of gasses dissolving or not in the oceans will be more or less as they are now"

no, this is not correct. Henry's law depends on the partial pressures of the gasses. If the amount of CO2 increases in the atmosphere, its partial pressure goes up, but the partial pressures of other gasses do not, so their solubility is unchanged.

"as CO2 is just 0.04% of the gasses likely to be dissolved (or not) in the oceans, we are not talking about a huge quantity in the scale of things, here"

Again it is the partial pressure of the gasses that determies their solubility, so this argument is incorrect. The partial pressure of CO2 has increased by about a third, which is why its solubility has increased so much.

"Now, you resort, once more, to the rise in CO2 being primarily anthropogenic (with little evidence to support this); "

I have given you a reference to my paper and also an article on SkS that outlines the multiple lines of evidence, so it is not correct to say that there is little evidence to support this, there is a lot of evidence to support this finding.

"why are the CO2 levels observed higher over the rainforests than over urban areas?"

CO2 in the atmosphere is well mixed, if you look under the inversion layer, you will find levels are very high over urban areas. Also rainforests contain more than just trees, I suspect you will find soil respiration is rather high in rain forests, and also trees also respire (produce CO2), the only CO2 they take out of the atmosphere permanently is that tied up in their annual growth. The carbon cycle is quite complicated, and you need to consider all factors. Without further details it is difficult to answer the question more fully.

" I have seen many sources where the proportion of human-generated CO2 is about 3-5% of the total rise;"

yes, this is explained in my paper, and is to do with the residence time. Essentially there are vey large exchange fluxes of CO2 between the atmosphere and the oceans and terrestrial biosphere. These rapidly exchange molecules of CO2 from fossil fuel use with molecules from natural sources (within about 5 years). However this is a straight swap and so does not cause an increase in atmospheric CO2. This is a very common misunderstanding of the cabon cycle on climate blogs. Ferdinand Engelbeen has been tireless (and very polite) in explaining this on a range of skeptic blogs, his website is a valuabel resource that you should investigate http://www.ferdinand-engelbeen.be/klimaat/co2_origin.html

" Is someone lying, or otherwise deliberately misleading?"

there is no need to introduce suggestions of dishonesty or malice. People make errors and they misunderstand things, that is explanation enough.

Aug 21, 2014 at 1:15 PM | Unregistered CommenterGavin Cawley

JohnShade If you email the author of a paper, they will quite often send you a pre-print if you ask (provided it is for personal use etc. and the journal's conditions permit it, which they do in this case).

"The fact that uncertainties in the sizes, and fluxes, of various natural sources and sinks are way larger "

You don't need to know the values of the uncertainties in the natural fluxes to deduce that the natural environment is a net carbon sink, and hence is opposing, rather than causing the rise in atmospheric CO2. You only need the annual growth rate, and anthropgenic emissions, the data on both of which Prof. Salby says are reliable. See the SkS link I gave earlier or my paper for details.

Humlum et al make the same mistake as Salby (the correlation in question has no mathematical connection whatsoever with the long term increase), and also was unaware of the work of Bacastow and others who have studied this issue before. Note that Humlum's paper was subject to a peer-reviewed comment paper that points out the flaws in paper.

Sorry if my posts are becoming a little terse, but there is only one of me, and a lot of points have been raised. They key point though is that the correlation that Salby and Humlum point out was already well known and understood, and has no mathematical connection whatsoever with the long term increase, so the argument based on it is fundamentally flawed.

Aug 21, 2014 at 1:25 PM | Unregistered CommenterGavin Cawley

FWIW, I would say that the carbon cycle is more like the planets main thermostat, rather than its control knob (as it mostly acts as a feedback in the pre-industrial world), but that our emissions are messing with the thermostat.

Aug 21, 2014 at 1:28 PM | Unregistered CommenterGavin Cawley

Gavin Cawley

FWIW, I would say that the carbon cycle is more like the planets main thermostat, rather than its control knob (as it mostly acts as a feedback in the pre-industrial world), but that our emissions are messing with the thermostat.

I'll repeat what I said earlier and ask isn't nature adjusting the thermostat on its own?

As far as I'm aware the evolution of C4 plant types occured about 25 million years ago, in response to falling CO2 concentrations. C3 plants are the majority at about 95% of all biomass need greater than 200ppm to survive. C4 plants are better in low CO2 and more arid conditions and are much better at carbon fixing at about 30% of the total currently. This suggests that a continuing decline in atmospheric CO2 content and a move to C4 carbon fixing by plants is quite likely without a natural process, such as increased vulcanism, which increases CO2 in the atmosphere.

Aug 21, 2014 at 1:43 PM | Unregistered CommenterSandyS

Gavin Cawley
My apologies. I am covered with embarrassment since I reckon if you can't get somebody's name right you're probably not worth listening to in the first place. I shall take myself off to the naughty step for an hour!
As for contributing to SkS I will leave that to those better qualified in science than I am and hope that you are correct in what you say though the experience of some on here is that disagreement with their in-house gauleiter is enough to get you 1. insulted and then 2. banned.
Maybe things have changed.

Aug 21, 2014 at 1:49 PM | Registered CommenterMike Jackson

Mike, no problem (it is usually my surname that gets mis-spelled - I'm quite used to that! ;o).

Aug 21, 2014 at 1:57 PM | Unregistered CommenterGavin Cawley

SandyS plants are a component of the carbon cycle thermostat, but I was thinking more of the weathering thermostat (high temperatures increase the rate of weathering of silicate rocks, which removes CO2 from the atmosphere, tending to regulate temperatures back down again over long timescales).

However, that is getting away from the key question "So where are Salby and Darwall wrong .... precisely?", which I have answered earlier in the thread. The correlation he discusses cannot explain the cause of the post-industrial rise as there is no mathematical connection between the two.

Aug 21, 2014 at 2:05 PM | Unregistered CommenterGavin Cawley

SandyS
"This suggests that a continuing decline in atmospheric CO2 content and a move to C4 carbon fixing by plants is quite likely without a natural process, such as increased vulcanism, which increases CO2 in the atmosphere."

You are partly correct. The earth has a natural thermostat that operates to draw down CO2 levels over very long time scales. Long being 10's of millions of years and longer. On these time scales the planet has two basic flows of CO2. Out of the Earth and into it. Volcanism is the long term source of Carbon being added to the surface. And a process called weathering reverses this and moves carbon back deep underground.

Weathering is a series of chemical reactions. First CO2 and water react in the atmosphere too produce carbonic acid - a very weak acid. This falls out in the rain and initiates chemical weathering in some types of carbonate and silicate rocks. Not erosion, more like very slowly dissolving them. The minerals dissolved eventually flow to the sea where they become part of the carbon cycle in the ocean. Ultimately they end up in the shells of tiny marine life that get deposited in sediments and eventually are subducted underground to eventually be vented as volcanic CO2 again 10's of millions of years later.

Importantly the chemistry of this weathering process is temperature dependent, running faster at higher temperatures. So if the earth is warmer weathering tends to draw down more CO2, cooling the planet. Conversely when it is cool it runs slower allowing volcanic CO2 to build up, warming the planet.

Since weathering is unconcerned with why the earth might be warmer it will tend to counter any warming influence - higher CO2 levels, warming Sun, whatever. So over very very long time scales the weathering system has tended to keep drawing CO2 down to compensate for a slowly warming sun.

But its not perfect and can be disrupted. Changes in volcanic activity can change the quantities of available rock surface on which weathering can occur, altering the weathering rate independent of temperature. Other processes might also impact on CO2 levels, compounding what the weathering system is doing. For example, during the Devonian and Carboniferous periods massive expansions in plants - the first great forests - locked up huge quantities of carbon then buried it as coal, We are burning that today. This altered the carbon balance so that a period of colder temperatures ensued.

So the weathering system is one factor that can twist the CO2 control knob, influencing climate. So too can volcanism and photosynthesis. And smart ape-persons who discovered fire. We all twist the knob from time to time.

Aug 21, 2014 at 2:45 PM | Unregistered CommenterGlenn Tamblyn

RR (wrt 4000 ppm 1000's of years ago0
"I might be in error, but do not think so. I cannot remember where I have seen those figures, but it was on more than one site, and, to tell the truth, can’t be bothered looking for them again. I am dismissive of those who cannot find it as I feel that, if I can find it, then it cannot be too difficult to find."

Sorry RR but the ball is in your court. All the evidence I have ever seen says that CO2 concentrations have been at scales of 100's of ppm for 10's of millions of years. The last time CO2 was at 4000 ppm was well before the death of the dinosaurs. Ice core records going back nearly 1 million years for example put CO2 at between 180 and 280 ppm.

Over to you.....

Aug 21, 2014 at 2:50 PM | Unregistered CommenterGlenn Tamblyn

JohnShade If you email the author of a paper, they will quite often send you a pre-print if you ask (provided it is for personal use etc. and the journal's conditions permit it, which they do in this case).

Aug 21, 2014 at 1:25 PM | Unregistered CommenterGavin Cawley

That has always been my experience in other branches of science or in engineering research.

But in the case of climate science my requests for a preprint (posed politely and explaining that I have neither library facilities nor a budget to access paywalled material) have very rarely received any response.

Climate science as a field seems to unique in various ways.

Aug 21, 2014 at 3:04 PM | Registered CommenterMartin A

ATTP: I do seem to be conflated you two; sorry if it causes offence or confusion to either of you. My posts may be a little abrasive – that is because I am in a rather cantankerous mood at the moment, so apologies, again. I know I should be looking up the sources I mentioned, but do not have the time nor the patience – another thing that annoys me. Until I can be bothered looking it up, consider me wrong and corrected. And count yourself lucky; you only have to meet me on these boards – I have to live with me all the time!

As for my comment: “Is someone lying, or otherwise deliberately misleading?” there is strong evidence that people are, on both sides of the argument, most likely for political and/or financial gain; sadly, some of these people claim to be scientists. This is where the argument has gone, and we do have to bring it back to science, to look at facts, no matter how harsh they may be, and not rely on “consensus” or “evidence” from models. (A good case in point is why is there such vehement denial about the 17-year pause in the rise in temperatures?) The whole planetary system is hugely complex, and we have only really begun to scratch at the surface. I doubt that there is one single controlling factor in the climate; I would not be surprised if we never fully understand the dynamics of the system, all we can do is observe and rationalise. Some – perhaps even most – of the theories that have been or will develop will prove to be nowt but hogwash; this does not mean that they should not be considered, nor does it mean that the proponents be ridiculed if wrong, for without error there can be no progress.

As for my doubts about CO2 being the key factor in global temperatures, you only need look at the fact that, though CO2 levels continue to rise, temperatures are not – also, it is often mooted that the “catastrophic” rise in human-produced CO2 commenced soon after WWII (certainly, the use of “fossil” fuels increased); odd, then, that for 30 years, the temperatures fell, until we were warned of the oncoming ice-age in the 1970s; odd, too, that the freezing catastrophists of that time are the same who say we are doomed to heat, now. They were wrong in their doom-mongering, then; why should they now be right?

Aug 21, 2014 at 3:26 PM | Registered CommenterRadical Rodent

RadicalRodent wrote "As for my comment: “Is someone lying, or otherwise deliberately misleading?” there is strong evidence that people are, on both sides of the argument, most likely for political and/or financial gain ..."

but say they are, does it mentioning it make the discussion more productive or less, in terms of getting to grips with the science?

"A good case in point is why is there such vehement denial about the 17-year pause in the rise in temperatures?"

I think this is another occasion where it is not dishonesty, but mistakes and misunderstaindings. I don't think anybody questions the fact that GMSTs have been quite flat since about 1998. However that does not mean that the underlying rate of warming is unchanged, or that anthropogenic global warming has stopped. This is because estimating a trend in noisy (autocorrelated) signals is subject to uncertainty, and currently, this uncertainty does not exclude the possibility that global warming has stopped, but it doesn't exclude the possibility that it has continued at the same rate and that the apparent hiatus is just an artefact of weather noise. Part of this is due to a lack of understanding of statistical tests of trends (I work in a branch of statistics, so the errors are fairly easy for me to spot, but not for someone without a good statistics background).

The hiatus is not ignored, it is actually quite widely discussed in the literatire, because it is interesting. See for example the recent special issue of Nature Geoscience on this topic http://www.nature.com/ngeo/focus/slowdown-global-warm/index.html .

There is no vehement denial of the 17 year hiatus, but there is genuine disagreement on what it actually means, and climatologists have taken the time to investigate in detail (e.g. Easterline and Wehner's paper).

So in this case, it is very obviously a case of error and misunderstanding, rather than dishonesty and misrepresentation.

There is a thing called Hanlon's razor, which says that "never attribute to malice that which can be adequately explained by stupidity". I prefer a more moderate version of it, namely "always interpret the comments and behaviour of others in the best light that is consistent with the observations". While there are dishonest people in the world, it does us no good to go looking for more of it, or to see it where it actually doesn't exist and it is just our error or misunderstanding.

Anyway, this is getting further and further from the key topic, which is "So where are Salby and Darwall wrong .... precisely?". As I have explained, this lies in detrending the CO2 data (by looking at the growth rate) before comparing it with temperature (correlations being insensitive to additive constants, which is what the trend becomes after differentiating to get the growth rate).

Aug 21, 2014 at 3:55 PM | Unregistered CommenterGavin Cawley

Well, well, ... if it isn't 'AndPhysics' and the guy who hides behind in the secret forum at Skepticalscience.

There is a bit of a back-story to Mr. Physics' obsession with Salby. In October last year AndPhysics ran a thread on his blog on how 'frustrated' he was that people took Salby seriously. It was so obvious to him that Salby was wrong. Salby's Hamburg video is the best available explanation of his ideas and his claims are quite specific - if you want to be charitable to his arguments. His argument, mainly, is that the [1] IPCC/orthodoxy derived proof that CO2 rise is anthropogenic is flawed. [2] Note how this is different from saying atmospheric CO2 rise is not anthropogenic

I commented on the thread, taking issue with one Tom Curtis who at that time was on one of his 'consensus promotional rounds' saying anyone who disagreed with experts must be an idiot. I used the example of breast cancer screening by mammography to say how experts may be wrong and disagreement was possible.

Ticked off, AndPhysics and others wanted the short-cut: "Tell me if you think Salby is correct. Tell me if you think atmospheric CO2 is not anthropogenic. I don't want to listen to anything else. Answer the question. Answer my question. Answer it NOW"

Note that AndPhysics' trick was to switch [2] for [1].

My point was to say - I did not believe that was Salby's argument. That was not his point. If you want to discuss - take up issue with something specific Salby has to say, anything specific - and show how it is definitely wrong'.

Mr. Physics threw up his hands: he concluded - per Salby - an increase in temperature would out-gas dissolved CO2 from oceans and this was Salby's proposed mechanism for temperature-mediated CO2 rise. A mere application of Henry's Law for ocean would blow Salby's theory out of the water. He reiterated this point several times.

In the next thread on his blog, AndPhysics proceeded to build a simple model that proved its own assumptions: increases in temperature did not produce enough of a rise in atmospheric CO2 owing to out-gassed dissolved CO2. Something Salby had never claimed. But that was no objection - AndPhysics had shown him wrong! Hurray.

What does one do but chuckle at this point? I explained several times how My.Physics' half-assed reasoning was abortive, circular and only proved its own underpinnings. No use.

At a later point, following further mockery, AndPhysics banned me from his blog. This is my first time getting banned from a blog because the owner couldn't stand being told he was wrong.

How do I know this? Recently, AndPhysics admitted that his application of Henry's Law to the oceans does not completely prove Salby wrong. This, after a span of several months.

It cannot get any funnier.

Postscript:
Showing Salby's arguments wrong would mean you take it seriously at least for sake of argument. The AGW crowd does not play that way. For them, argument consists of John Mashey spending time on Google digging up dirt, followed up by Readfearn or Nuccitelli or some such smear-artist writing hit pieces on their blogs.

AndPhysics cannot put in the hard work required to show why Salby is wrong and which specific point is wrong. Instead his sources are Skepticalscience and Guardian articles. Examine commenter Marco on AndPhysics' blog latest thread:

ATTP, the picture you provide is not evidence as such, since it is a schematic representation of what we know. Salby challenges that we know this.

This simple point is lost on this jacked-up 'physicist'.

Aug 21, 2014 at 4:58 PM | Registered Commentershub

I baulk at having to pay $35 to read one of his papers which he links to.

That's why world class university research libraries are free and open to the public. I think it costs at most 10 cents a page to copy these articles or print out the pdfs. You have no excuses for not following the literature when your naive and silly arguments are dismissed or destroyed by those who do. Find a free two hour parking space, walk and do the work.

Aug 21, 2014 at 5:07 PM | Unregistered CommenterThomas Lee Elifritz

How refreshing it is to discuss matters openly, huh Gavin? Instead of hiding at welloinkedcatherd?

You say: "There is no vehement denial of the 17 year hiatus"

You and your team made an 'Escalator graph'. The graph implied, or showed, flat periods in global temperature when there was a long-term rise. You and others used to imply the people who were talking about the pause were fools for imagining things that did not exist.

You kept saying the same thing *until enough papers had appeared on the topic from your favoured scientists* - such scientists as ... Lewandowsky.

Today you say there was 'no vehement denial' and that it is 'quite widely discussed in the literatire (sic)' and that 'climatologists have taken the time to investigate in detail'.

An article appeared in 2008 in Science magazine discussing the pause. David Whitehouse wrote about the pause in 2005, possibly even earlier. To those who talked about the pause, then - you waved the escalator graph in their faces. Today you sing a different tune.

Aug 21, 2014 at 5:25 PM | Registered Commentershub

shub wrote "How refreshing it is to discuss matters openly, huh Gavin? Instead of hiding at welloinkedcatherd?"

sadly this sort of thing is pervasive in discussion of climate on blogs. Sorry, I would be happy to have a polite discussion of the science, but I have no interest whatsoever in partisan "blog wars" rhetoric like this. So if you want me to continue the discussion with you after this post, please adopt a more reasonable and scientific tone.

The point made by the escalator diagram is just as valid today as it has ever been, which is that cherry picked short term trends, are meaningless. There are good statistical methods for analysing trends (e.g. as implemented in the SkS trend calculator). If you look at the error bars on the trend estimates for such short periods, you will find them to be so wide that you can't draw any conclusion from them. The problem is in asserting that the apparent hiatus in GMSTs mean there has been a hiatus in the underlying rate of warming. This is not correct as a proper statistical analysis shows that the hiatus is still plausibly an artefact of weather noise. The purpose of the nature article is to understand the reasons for the hiatus and to determine whether it actually is an artefact or whether there has been a change in the underlying rate of warming.

Personally, I suspect it is probably mostly artefact, because ocean heat content has continued rising, which suggsts the hiatus is simply due to a change in the exchange of heat between the surface and oceans, but the planet as a whole is still accumulating heat at much the same rate. This is reinforced by the evidence of Foster and Rahmsdorf, which suggests the hiatus largely goes away of you account for the effects of ENSO.

Aug 21, 2014 at 5:45 PM | Unregistered CommenterGavin Cawley

Gavin
The thing about these discussion threads is that, like discussions in the local pub, they tend to wander away from the subject matter a bit on occasion though they often find their way back there.
But the question of the "pause", while not perhaps being central to this discussion, is not totally off-topic.
The question posed initially includes (to my mind) the question of why it is that supporters of the consensus are very quick to condemn out of hand scientists of repute whose work — sometimes published, sometimes not (reasons we shall leave aside for the moment) — disagrees with the consensus. I would say that your replies do not fall into that category!
BUT ... the history of climate in the 20th century and, as far as we have accurate records, the 19th century also is of ~30 years of warming, ~30 years of cooling/stasis, and so on to about 2000. On that basis we are currently in a period of stasis perhaps leading to cooling or perhaps in which cooling has already begun.
And yet the consensus establishment is using every trick it can think of, from "the ocean ate my warming" onwards, to insist that this is only a pause (at least they have at last admitted that; it took years to wring that concession out of them) and that warming will come roaring back next year or maybe the year after but certainly by the year after that in the face of historical evidence that this current warming/stasis phase from the mid-70s is in effect no different from any other.
And they provide no convincing reason to back up their argument. Hand-waving, assertion, lots of 'may', 'might', 'consistent with', obfuscation, insult even. All the tricks that those of us with the average number of brain cells recognise as the desperate flounderings of people trying to hold together an idea whose time has gone. We don't need to be talking climate here; those of us with years of experience in business, education, local government, you name it, recognise the signs. They are the same in every walk of life. They've bet the farm on a hypothesis or a political philosophy or course of action and the facts are refusing to play the game.
In a sense whether Salby is right or wrong is irrelevant. In a sense whether you are right or wrong is irrelevant.
CO2 is supposedly the main driver of late 20th century warming.
CO2 started to increase around 1800-1850 and yet it had no effect (the consensus says) until 1975.
CO2 continues to increase and yet there has been no warming since 1997.
Don't you see a major disconnect here?
And then ask yourself the age-old question, cui bono?

Aug 21, 2014 at 6:12 PM | Registered CommenterMike Jackson

Mike Jackson wrote "... the history of climate in the 20th century and, as far as we have accurate records, the 19th century also is of ~30 years of warming, ~30 years of cooling/stasis, and so on to about 2000"

The human eye is all too good at seeing patterns and cycles in noisy data, where no underlying cyclical physical process is actually at work, and instead the apparent cycles are due to the interplay of a variety of other factors and the noise. In the case of climate, long term temperature variations depend on a wide variety of forcings, including solar, volcanic and anthropogenic forcings. None of these have been constant over this period, so for there to be an actual cycle, you first need to show that the cycle still exists once these known forcings are properly taken into account, or show that the climate does not respond to these forcings. Most attempts to model the climate using such cycles (e.g. Loehle and Scafetta) notably ignore the forcings, and so find a cycle where none (likely) really exists.

"And yet the consensus establishment is using every trick it can think of, from "the ocean ate my warming" "

these aren't tricks, they are genuine attempts to understand the observations using physics (apart from the rhetorical label). ENSO is known to have a big effect on GMSTs (water has a very high heat capacity relative to the air, so you only need a fairly small change in ocean temperatures to have a substantial effect on GMSTs). Thus controlling for the effects of ENSO is a perfectly reasonable thing to do in investigating the hiatus, even if it isn't represented that way on the blogsphere.

"to insist that this is only a pause"

IIRC, the special issue of nature contained some papers that did not say that the underlying rate of warming had continued. There are certainly papers (e.g. Fyfe that contend that models have overestimated climate sensitivity based on the hiatus, although I think in that particular case the statistical argument is flawed). So it is not the case that the mainstram scientists are insisting anything, it is very much up for discussion, hence the special issue of Nature.

"And they provide no convincing reason to back up their argument. "

no, as I pointed out, it would be very strange if ENSO and ocean circulation in general didn't have a substantial effect on GMSTs.

"Hand-waving, assertion, lots of 'may', 'might', 'consistent with', obfuscation, insult even. "

There is no hand-waving in Foster and Rahmstorfs paper, but solid statistics. Also "may" "might" "consistent with" are the language of science. Science frequently cannot give unequivocal answers, and not overstating your findings is key to good science, hence the use of such terms. Note "consistent with" has a specific statistical meaning, which is quite important as "not consistent with" is a very strong statement. Regarding obfuscation, it is better to assume that you are missing some subtle point rather than that the point is being obfuscated, self-skepticism is central to being a scientist. Afterall, they are the ones who have invested their careers in investigating this problem so they pobably understand it better than you do, so if you assume it is your own error, you will usually be right.

"We don't need to be talking climate here; those of us with years of experience in business, education, local government, you name it, recognise the signs. "

I think your background is leading you astray then. Science is *very* differnt to business and governement, The vast majority of scientists pursue their work out of curiosity and go where the evidence takes them. It is a career limiting move to do otherwise as if you deliberately follow an agenda that isn't supported by the facts, you will quickly be found out and your reputation will be in tatters.

"CO2 is supposedly the main driver of late 20th century warming."

that woulld be a reasonable summary of the IPCC position

"CO2 started to increase around 1800-1850 and yet it had no effect (the consensus says) until 1975."

no, that is not correct. It is not true that it had no effect prior to 1975, just that it became the dominant effect after about 1975. There is also the fact that e.g. aerosol forcing has been masking some of the effects of GHGs, and legislation has resulted in a reduction in this masking. The IPPC position is that you need both natural and anthropogenic forcings to explain the observed climate of the 20th century, which seems a pretty reasonable position to me.

"CO2 continues to increase and yet there has been no warming since 1997."

The expected rate of warming due to CO2 is quite small compared to the effects of internval climate variability (such as ENSO) on short timescales. As Easterling and Wehner showed, it is not unusual to see decadal or longer periods with little or no warming in the presence of a long term trend for this reason. We see it in the observations, and we see it in model output as well (but the models cannot predict when they will happen). For an example of a previous decadal trend with no warming, see this plot of RSS temperatures: http://i.stack.imgur.com/3rcib.png

"Don't you see a major disconnect here?"

No, I see some misunderstanding of issues in statistics and climatology, but no major disconnect.

"And then ask yourself the age-old question, cui bono?"

Physics doesn't depend on motives. As I have pointed out, it is a career limiting move for scientists to do anything other than follow where the evidence leads. Scientists (and academics in general) make a living by proving each other wrong, that is largely how science proceeds (ask Karl Popper), so the idea they are all in some sort of organised deception for personal gain is a non-starter. It isn't as if being a scientist is a particularly profitable career (compared with business or government), and the scientists don't get to keep the grant money anyway, most of it goes on hiring research assistants.

I think that will be my last post here. Once discussion of science moves onto discussion of motives etc. the chances of reaching agreement on the science rapidly diminishes. I hope the explanation of the particular error in Salby's reasoning is of interest; if anyone wants a copy of my paper, send me an email.

Aug 21, 2014 at 7:00 PM | Unregistered CommenterGavin Cawley

"So if you want me to continue the discussion with you after this post, please adopt a more reasonable and scientific tone."

Is that so? The escalator graph is 100% non-reasonable and pseudoscience. I did not see you protesting. Discussion involves two people. You must imagine it to be something else? Blog partisanship as excuse is valid only if there is personal attacks, censorship or a combination of both. You are free to comment and your points are being replied to.

In the escalator graph, you draw little horizontal lines of ~10 years. These lines imply short periods can show little or no temperature rise with an overall rising trend. Fair enough.

Starting 1998, however, you draw not one but two little blue lines to the present. Why? Is it to draw attention away from the fact that the 'pause' is longer than implied by the other lines? It had to be broken into two pieces to sustain its own message.

The escalator graph includes only the satellite era. Why? If one includes the previous 1940 to 1970 period, there would be a 30-year long horizontal or downward-sloping blue line. Would that still be consistent with the graph's title of "how 'skeptics' view global warming'?

Discussing the pause and carrying out 'scientific' discussions about it is fine but given that it was not predicted and given that the people who drew attention to this phenomenon in nature were mocked, it has to be conceded the science here amounts to little more than post-hoc rationalizations. Almost anything can be explained this way except they don't count as explanations.

Aug 21, 2014 at 7:04 PM | Registered Commentershub