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The CERN/CLOUD results are surprisingly interesting…

Filed under: — gavin @ 24 August 2011

The long-awaited first paper from the CERN/CLOUD project has just been published in Nature. The paper, by Kirkby et al, describes changes in aerosol nucleation as a function of increasing sulphates, ammonia and ionisation in the CERN-based ‘CLOUD’ chamber. Perhaps surprisingly, the key innovation in this experimental set up is not the presence of the controllable ionisation source (from the Proton Synchrotron accelerator), but rather the state-of-the-art instrumentation of the chamber that has allowed them to see in unprecedented detail what is going on in the aerosol nucleation process (this is according to a couple of aerosol people I’ve spoken about this with).

This paper is actually remarkably free of the over-the-top spin that has accompanied previous papers, and that bodes very well for making actual scientific progress on this topic.

The paper first confirms some results that are well known: aerosol nucleation increases enormously when you add H2SO4 into the air (the biggest contributor to human aerosol impacts via the oxidation of our emissions of SO2), it increases further when you add ammonia (NH3), and it increases even more when you increase ionisation levels from neutral, to ambient ground levels, and to upper atmospheric levels (as long as you are below what is called the ‘ion-pair’ limit). However, the most intriguing result is that despite going to a lot of trouble to make sure the chamber was ultra-free of contaminants, the researchers found that within most of the aerosols that formed, there were traces of organic nitrogen compounds that must have been present in almost undetectably low concentrations. The other intriguing finding is that aerosol nucleation rates in the chamber don’t match (by a an order of magnitude or more) actual formation rates seen in real world near-surface atmospheric layers at realistic temperatures (only in unrealistically cold conditions do rates come close). The authors speculate (quite convincingly) that this is precisely because they didn’t have enough volatile organic compounds (which are ubiquitous in the real world) to help get the nucleation started. This result will surely inspire some of their next experiments. All-in-all this is a treasure trove of results (and potential future results) for people tasked with trying to model or understand aerosol processes in the atmosphere.

Annotated Fig 5 from Kirkby et al
Figure 1: Annotated version of fig 5 in Kirkby et al. Small dots are in situ observations, lines are other lab data. Colours for the CLOUD results are coded with respect to temperature. Going from open to filled symbols denote increasing NH3. All results are for ambient CR ionisation (changes in CR only make a difference below the ion-pair limit).

However, aerosol nucleation experiments are not usually front page news, and the likely high public profile of this paper is only loosely related to the science that is actually being done. Rather, the excitement is based on the expectation that this work will provide some insight into the proposed cosmic ray/cloud/climate link that Svensmark (for instance) has claimed is the dominant driver of climate change (though note he is not an author on this paper, despite an earlier affiliation with the project). Indeed, the first justification for the CLOUD experiment was that: “The basic purpose of the CLOUD detector … is to confirm, or otherwise, a direct link between cosmic rays and cloud formation by measuring droplet formation in a controlled test-beam environment”. It is eminently predictable that the published results will be wildly misconstrued by the contrarian blogosphere as actually proving this link. However, that would be quite wrong.

We were clear in the 2006 post that establishing a significant GCR/cloud/climate link would require the following steps (given that we have known that ionisation plays a role in nucleation for decades). One would need to demonstrate:

  1. … that increased nucleation gives rise to increased numbers of (much larger) cloud condensation nuclei (CCN)
  2. … and that even in the presence of other CCN, ionisation changes can make a noticeable difference to total CCN
  3. … and even if there were more CCN, you would need to show that this actually changed cloud properties significantly,
  4. … and that given that change in cloud properties, you would need to show that it had a significant effect on radiative forcing.

Of course, to show that cosmic rays were actually responsible for some part of the recent warming, you would need to show that there was actually a decreasing trend in cosmic rays over recent decades – which is tricky, because there hasn’t been (see the figure).


Figure 2: Normalised changes in cosmic rays since 1953. There has not been a significant downward trend. The exceptional solar minimum in 2008-2010 stands out a little.

The CLOUD results are not in any position to address any of these points, and anybody jumping to the conclusions that they have all been settled will be going way out on a limb. Indeed, there is a lot of evidence that (particularly) point 2 will not be satisfied (see for instance, Pierce and Adams (2009), and a new paper by Snow-Kropla et al).

So what changes did they show as a function of the CR activity? In going from neutral (shielded) conditions to ambient CR levels typical of the lower atmosphere, the ionisation changed by a factor of 2 to 10 (depending on the temperature – colder conditions are more sensitive). However this is a much bigger change (by an order of magnitude or more) than the percentage change in CR activity over a solar cycle (i.e. ~10-20%). A rough calculation (by way of Jeff Pierce) that takes into account the square root dependence of ion concentrations on GCRs and the neutral nucleation in the CLOUD results, suggests that for average conditions the solar modulation of GCR would impact nucleation by about 1% – rising to perhaps 12% for the biggest changes in GCR seen in figure 2 at very cold temperatures. Thus the nucleation change as a result of real world GCR modulation is going to be much smaller than seen in these experiments, and much less important than the amount of pollutants.

In summary, this is a great example of doing science and making progress, even if it isn’t what they first thought they’d find.

220 Responses to “The CERN/CLOUD results are surprisingly interesting…”

  1. 201
    arch stanton says:

    Gordon – Theo, Kevin, Hank and Ray are being gentle with you.

  2. 202
    Theo Kurtén says:

    Gordon: molecular weights don’t really matter for molecular lifetimes (or mixing, or whatever) in the troposphere: google “troposphere well-mixed” or something similar for an explanation. This is elementary stuff. What *does* matter is stuff like oxidation rates (for lifetimes with respect to chemistry), volatility (for lifetimes with respect to condensation), solubility in water, etc. (And the total lifetime will of course be determined by the *largest* sink- it doesn’t matter if some gas is really volatile, if it is quickly oxidized. Or vice versa – oxidation reactions won’t matter if the gas immediately condenses onto any surface.) I humbly suggest you read some atmospheric chemistry textbook first, and then get back to planning your experiment.

  3. 203
    Samium says:

    Let me please remind you what exactly I’ve pointed first: Gavin’s statement that

    Of course, to show that cosmic rays were actually responsible for some part of the recent warming, you would need to show that there was actually a decreasing trend in cosmic rays over recent decades – which is tricky, because there hasn’t been (see the figure).

    Please note that he vaguely told about ‘recent decades’. Which let us with the following alternative: either he was thinking about possibly more than 5 decades, or less. But in the former case, his other statement, that ‘there hasn’t been [any decreasing trend in cosmic rays over recent decades]’ wouldn’t be valid. Conclusion : he was actually talking about less than 5 decades for the GCRF trend, meaning that he told about a trend in the input being observed in the same period as the output, or a period of lower duration in this period. Which is what any reader would have understood at first glance.
    I first replied:

    sorry to be that rude, but Gavin seems to have mixed heat transfer and temperature, even radiative net flux and temperature. It’s like mixing a function and its integral, if you allow me to use a simple picture.

    Interestingly, the atmospheric 10Be concentration has been remarkably constant in the last 50 years… but changed a lot before: from ~11 000 atoms/g in 1900 to ~7 000 atoms/g since ~1960!

    Gavin responsed that:

    Warming rates would be maximum at the beginning of the ‘plateau’ and decay almost immediately (giving an exponentially slowing warming as you reached equilibrium with the new state). You don’t get acceleration of the warming after the forcing has plateaued, and certainly not 20 to 30 years later.

    I’d simply like to know how Gavin expects (in case the GCR-cloud effect works) both a zero trend on the temperature when GCRF is on a ‘plateau’ and the increasing rate (with damping) he’s talking about in his answer.
    I’m not a ‘climatologist’, not even a a researcher but I’m not that stupid to believe one can reconcile both. In other words, his answer not only fails to show I was wrong but implies that his own initial statement was wrong.

    This discussion ended with the image of the bath with watter level and flows in and out. Which again brough Gavin to reply something we all know, without cancelling my statement that one of his statements is wrong: in the case of climate, the heat flow out depends on the temperature. So things are ‘a bit’ more complicated, etc. Anyway, this doesn’t bring any contradiction to my point, and of course he knows that.

    Then Brian Dodge had a reply similar to Gavin’s, with a few additional details about fluid mechanics. However, this doesn’t contradict my initial statement that Gavin’s was wrong. I’d like to draw Brian Dodge’s attention on the fact that, despite of the square relation of the flow to the pressure gradient, the water level in the bath will climb up if the flow in is big enough, and that this only marginaly due to turbulent losses in the sink ; the main reason is simply that, if we postulate a given high value of the flow in, the watter level in the bath won’t be high enough to induce a sufficient flow out to cancel the flow in.

    BTW, note that the (highly filtered) temperature trend was not constant for 5 decades if you account for the fact that, around 1965, so just after the beginning of the ‘10Be low plateau’, the trend changed from a negative value to a positive one… Of course we probably have oceanic currents regime as the main agent here, if we think about some kind of sine wave response, but I’m talking about something like a possible triggering, inducing a figure more like the temporary behavior of a triangular function in response. After what the lack of increasing gradient could also well correspond to the effects of the damping Gavin mentions… Simple conjecture, here, but please try and stick to the main point about Gavin’s statement, not only about possible mistakes in mine.

    One last thing: Gavin’s treatment of my remark about a same reasonning with CO2 doesn’t seem very fair.

    I said :

    Incidentally, Gavin should know that replacing ‘cosmic rays’ (GCRs possible radiative effects via low cloud cover) by ‘CO2’ in his same statement and considering, for example, the 1940-1970 period and numerous other ones (with or without man’s emissions) would lead him to the same disturbing and disappointing conclusion… How can he have missed that?

    Gavin just had a hand-wave, recalling what everybody knows: attribution needs to account for all potential effects at the same time. I was obviously thinking about the fact that, due to the same reason, lack of observable effects in some periods and conditions is not enough to prove lack of individual effect (the big issue being that nobody knows the list of all the factors, not to mention quatitative cumulative effects). And that, if it was, then Gavin could also apply the same reasonning to CO2, ‘which is tricky, because…

    Of course, this doesn’t cancel Gavin’s general hypothesis about GCR effect. But for the sake of the debate, let’s avoid mixing things.
    Let’s also avoind acting as if any mistake made by someone or another proves he should be considered wrong all along…
    Even when looking at things one by one (when possible), there’s a huge difference between showing a statement is wrong and bringing proof of the opposite statement (if existing). I’m quite sure you agree with that, and also with the idea that too many people often forget this basic distinction in the climate discussions. It’s important in the climate debate more than in many other ones, because we the big scientific issue with the ‘AGW theory’, at least when speaking about future events, is that it’s impossible to falsify it as hole, given the facts that it implies to wait a long time and that we’re often dealing with statistics for measurements though we only have one world and one future. So let’s try and honnestly falsify individual statements which can be falsified.

    [Response: If you don’t understand something someone says assuming that they therefore must be dishonest and self-contradictory is not generally a rational strategy when trying to understand some new topic. Nor is it conducive to further engagement on the part of your interlocutor. A better assumption is that you are not getting some key issue which, perhaps, had apparently gone without saying. That would not be unusual and I doubt that anyone would take umbrage at further questions aimed at clarifying issues. So, for the benefit of other readers I will assume that this comment is actually a request for clarification, and not the pejorative mess it might appear to be at first reading.

    1) Trends in GCR over the last 50 years. The graphs are very clear – apart from the 11 year cycle (and a 22 year overtone), there is no long term trend in GCR in any direct observation. No long term trend, implies no long term impact on climate via any mechanism that relies on a change in GCR.

    2) Impacts of changes prior to the neutron monitor observations. Let’s imagine that purely coincidentally that immediately prior to the beginning of the observations that was a big drop in GCR. There is no evidence for such a thing, but clearly it cannot be ruled out. (Similarly, a six foot rabbit may have disappeared from the closet just before I looked into it. Highly unlikely, but it is impossible to prove otherwise). What would have been the impact on temperatures assuming that GCR did actually have a radiative impact via clouds? The answer is the same as if there was a big jump in CO2, or an instant increase in solar irradiance. The radiative forcing would be at a maximum at the jump, and as the temperatures of the planet warmed up, it would decrease (eventually to zero, depending on the effective heat capacity of the system). The rate of change of temperature would be a maximum at the start and would decrease subsequently as it got closer to the new equilibrium. Thus, we would expect the maximum warming rate in 1950 (or whenever the hypothesised drop occurred) and a decrease in warming rates over subsequent decades.

    3) A simple model. If the system is described as c{dT\over dt} = F - \lambda T where T is the temperature anomaly, c is a heat capacity, F is the applied forcing from 1950 on and \lambda is the sensitivity. The solution is T=(F/\lambda) (1 - e^{-\lambda t/c}), the warming rate is (F/c) e^{-\lambda t/c} (max at t=0, exponentially decaying subsequently). (figure – using 100m ocean mixed layer, 0.6 C/(W/m2) sensitivity, instant forcing of 1 W/m2)).

    4) Does this model fit what has been observed? Not even close. And this doesn’t even get into issues related to stratospheric cooling (which is the opposite of what is predicted for any GCR mechanism), nor the lack of climate response to the Laschamp event 40,000 years ago, etc.

    5) With respect to causality, factor X cannot cause effect Y if factor X did not change while effect Y did. I fail to see how this is at all complicated. If I did not throw the baseball, it cannot have been my throw that caused the window to break. This conclusion remains regardless of whether factors Y or Z were changing at the same time. This is not the same issue as when factor X changes and effect Y does not since factors Y and Z might well have also changed. I may have thrown a baseball, but no window was broken. This might have been because my throw was off or the ball was intercepted.

    I hope that provides some clarification, and I would advise a little more courtesy in future if you want to engage. (Of course, if you don’t, feel free to insult all and sundry – just don’t expect a response). – gavin]

  4. 204
    Samium says:

    I will assume that this comment is actually a request for clarification

    You’ve got it. I’m not used to believe people being dishonnest. More a matter of having different viewpoints and mostly “deaf dialog” (sorry, probably a very bad translation from french) wich often come from badly expressed statements.

    1) Agreed (of course).

    2) What about the 10Be stricking change we told about? Do you mean that your own studies on 10Be measurements issue leads you to the conclusion that the claimed relation with GCRF is wrong to the point of no correlation at all? That would be some kind of a scoop, to me at least.

    That last big change (in 10Be) was around 1960: maybe there’s no nead to have an additionnal hypothesis on the date, i.e. 1950, then (or do you also disagree with the date ?)

    3) (If the 10Be – GCRF correlation is somehow valid, even with big precautions and) if we had this 10Be drop around 1960 and following plateau, you’re precisely saying here that the temperature would have shown a positive trend in the following decades.

    That’s only what I was saying. In turn, I fail to see how this is all complicated.

    However, your initial statement told about the last 3 decades, not 5. But once again, it’s perfectly unclear for the reader of the thread: why you’ve chosen that value (the 3 last decades); that your ‘recent decades’ (for the GCRF possible input) could refer to more than 3, while you look at 3 decades for temperatures; that your statement relies on the hypothesis that the flux imbalance lasts about 2 decades (your figure and associated values for c and lambda); that you also have serious doubt there was a significant CGRF drop around 1960; that yet this can’t be ruled out. This makes plenty of underlying assumptions and additional reasonning, regarding which the introducing ‘Of course‘ in your statement seems remarkably surprising.

    Anyway, you’ve got those two hypothesis: for the sensitivity, then for the delay (and maximum rate). Why not consider, say Shaviv [2005], i.e. 0.35? You didn’t indicate your value for heat capacity (in this simple model or whatever model your initial statement is based on).

    4) Your own words: attribution needs to account for all potential effects at the same time.

    I’m still ignorant about stratospheric cooling and Laschamp event issues, so: OK I’ll have an idea of my next readings. Thanks.

    5) Idem. The fact that the window was not broken doesn’t mean you’ve not thrown any baseball (yes).

    Now, I’m not sure this general point is that relevant here: 1) please remember I was commenting that statement of yours starting with ‘Of course,…; 2) even at that point of the discussion, unless additionnal evidence is given, were not talking about no trend, for temperature and for GCRF as well.

    No intentional lack of courtesy. Simply trying to get to the point. In any case, thanks for your answers.

  5. 205
    Gordon Jenkins says:

    “Strong sensitivity of late 21st century climate to projected
    changes in short-lived air pollutants” Hiram Levy II, M. Daniel Schwarzkopf, Larry Horowitz, V. Ramaswamy,
    and K. L. Findell (

    That’s a pretty good background article showing different scenarios for sulfates, CO2, carbon black etc. It would have been nice if somebody would pointed out such simple and elegant paper to me. It was published way back in 2008. I suppose somebody’s already challenged it.

    This website has lots of nifty stuff on it:

    Standard Gravity is about 9.807 meters per second per second (, so that’s probably why you see all this brown stuff down in the poorly mixed air in Shanghai
    (, or trapped up at 2,240m above sea level in Mexico City(
    Los Angeles is pretty nice too (
    Doesn’t physics trump chemistry, the former being superior and the latter, being inferior and subordinate to physics? After all isn’t everything physics? Why then tempt me with atmospheric chemistry, without first showing me the atmospheric physics?

  6. 206
    Ray Ladbury says:

    Samium, You know, you can either try to subject everything Gavin or any other scientist says to scrutiny normally reserved for the Talmud or Koran, or you can do the frickin’ math yourself.

    First, have you ever taken a science class?

  7. 207
    Doug Bostrom says:

    No intentional lack of courtesy.

    Not at all, more like flatulence. Perfectly excusable.

  8. 208
    ldavidcooke says:


    Hey Samium,

    Not to confuse the issue, as the prevalent belief is that shading of the Stratosphere from upwelling long wave by CO2 and reduced optical depth in the 15um range, is the main process resulting in a reduction of heat there. However I think there might be other possibilities yet to be explored, though as to the accuracy of these possible alternative influences, I have no evidence set. I believe part of the reason for the cooling in the Stratospheric region is due to a reduction of Ozone there. From my observations looking at the water vapor data in the Tropopause it appears there are a number of cases of super saturated water vapor being observed. (This would also be predicated on the idea that as in coming UV hits O3 a thermal reaction occurs…)

    As to the possibility of incoming UV warming CCN particles in the Tropopause, having passed through the Stratosphere without rasing the energy of a few O3 molecules, I can not tell. However, it may be a possibility that it plays a part. Whether this can account in some way for super saturated water vapor there, again I do not know.

    As to upwelling radiative flux, I also see a bit of confusion in that there are several excellent papers regarding long wave path ways from a black body or even a gray body. Though most are discussions of static conditions. If we consider the full dynamics with multiple pathways I believe some of the variations we may be seeing currently could better be explained. For instance when we consider not only evaporation and convection we also have a strong dynamic of advection. Hence, we can take a snapshot of the static state, though to map the dynamic state is pushing much of our current technology/modeling capabilities.

    The point for mentioning all of this, is where some look for GCR fluctuations and their effects on the formation of CCNs, I do not know if they are significant in the face of many other processes. Yes, it was demonstrated that in very high densities small aerosols did form; but, given natural densities it would take the accreation of a great number to begin to support the condensation surface pressures required. Hence as you go back to researching keep an eye out for the discussions regarding Stratospheric clouds near the polar regions. I believe they may be a clue, though of what I am not sure yet, lets just say evidence of a possible alternative long wave release pathway, different from surface upwelling. Good luck…

    Dave Cooke

  9. 209
    Hank Roberts says:

    > Doesn’t physics trump chemistry, the former being superior

    Boring with a dull bit.

  10. 210
    Theo Kurtén says:

    well, chemistry is of course based on, and subject to, fundamental physics. That’s why most atmospheric chemistry textbooks start out with a pretty long section on atmospheric physics. See e.g. Daniel Jacobs excellemnt book (available online) at:

    Trapping of pollutants near ground level is of course ultimately, though indirectly (via lapse rates and so on), dependent on gravity – but this does *not* mean that you can make any predictions about the fates of molecules based on their molecular weight. Or that you can ignore oxidation chemistry for reactive species… Please, please, please: Read. The. Textbook.

  11. 211
    Samium says:

    @ Ray Ladbury,

    science class? Oh, only engineering french diploma (I think you’d call it some kind of master’s degree) at INSA (National Institute of Applied Sciences), Lyon (recognized as one of the best schools in the country for technical level). Specialized in mechanics. How about you? Now, I must say I hate maths. Yet I think high school maths level is enough to figure out the physical meaning of the equations Gavin’s wrote here.

    In particular, that it’s based on a dF/dT = 0 hypothesis, which I’m afraid won’t help much here (to say the least), as it would somehow lead to fix the answer in the question. In other words, I’m mostly interrested in the effects of dF/dt here — and so is Gavin, as that parameter is obviously part of any reasonning which would lead to his initial statement — so why would I cope with a model that cancels this component in the first place? (No intentional lack of courtesy, I’m just saying those explanation doesn’t explain anything to me).

    I was objecting a staircase input function, when higly filtered (if reasonning on 10Be proxy), as opposed to a constant; moreover, there’s no ‘plateau’ indeed, the actual shape of that input function shows large and rather quick variations; unfiltered GCRF curves also show very large variations, more than +/-10%, not to mention the sharpest figures. Sorry to remind us climate is something chaotic, say full of non-linear functions — e.g. see the huge number of calories requiered for evaporation and for liquefaction of water with no temperature variation at the transition. It’s not lacking courtesy to express the fealing I sincerly don’t know what’s the use of a linear model dealing with global scale and “anomalies”. But even if I try and do that, why on Earth would I consider a fix value for F(t)?

    As for the last 5 decades, my own ckecking of GCRF raw data at a given place (HERMANUS, latitude -34,42°) with 11-years filtering yields not a single plateau after ~1963 but something more like a double one (transition in ~1979 to ~1987), with a significant decrease in the GCRF (-4,2%).

    Besides, this simple model: uses a small-variations coarse approach on T (showing no inverse fourth power relationship to the flux out); considers one part of an unknow net flux; drops any “feedback” while using “forcing” approach, as well as other fluxes except radiative ones; etc. But of course I won’t send him reproaches for that: I’m not mixing the initial statement and individual developpements made when further discussing. Just asking helpfull explanation.

    Anyway, as gavin put it, attribution needs to account for all potential effects at the same time, so who knows what conclusion to associate to the fact the 2 curves in his figure radically differ? I’d already suggested that he superimposed his (red) curve with others, one of them accounting for oceans heat discharge (modelled-based on regime indexes?) Of course, I’m not equiped to do such a thing; I can only comment saying: obviously the said shapes difference in Gavin’s figure doesn’t allow for any direct conclusion.

    All in all, I’m still suprised by that statement of Gavin’s starting with ‘Of course…‘ I hope asking questions about obviously lacking part of the exposed reasonning is not considered lack of courtesy.

    [Response: I have absolutely no idea what you are now ‘questioning’. The red line was calculated using the equation I wrote down and is completely typical of the response of a damped system to an instantaneous forcing. If you want to test different forcing histories go ahead. I guarantee that no function of the CR record (however you add on the 10Be records) will match recent trends in temperature. – gavin]

  12. 212
    Ray Ladbury says:

    Samium, PhD in physics–and I like math. It’s the language reality speaks. You should try it some time.

    Galactic cosmic ray counts were remarkably stable on average at least from ~1975 to 2010 based on single-event upset rates of devices in satellites. Neutron flux rates indicat constant back to at least the 50s.

    And in answer to my question, no actual science classes, I guess?

  13. 213
    Ray Ladbury says:

    Gordon Jenkins: “Doesn’t physics trump chemistry, the former being superior and the latter, being inferior and subordinate to physics? After all isn’t everything physics? Why then tempt me with atmospheric chemistry, without first showing me the atmospheric physics?”

    Reality trumps pudknocking about which science reigns supreme. Get serious!

  14. 214
    Jeffrey Davis says:

    I don’t understand the attraction of the GCR theory. Not only don’t you have a trend to account for, you’ve got to contrive a mechanism to vamoose the calculable effect of increases in greenhouse gases. After a bit of epicycle fiddling (to no apparent effect) wouldn’t most people just acknowledge that it’s a dry hole and move on?

    Assuming, of course, that you want to continue to be a serious scientist and not simply a polemicist.

  15. 215
    Samium says:


    the response of a damped system to an instantaneous forcing

    The adjective instaneous could be ambiguous when combined with the idea of damping. I mean, this simple model is not describing the response to a Dirac but to a constant F: by hypothesis, your equation, then F value, are expected to hold for any moment in a long period (several decades).

    Besides, your integration of c.dT/dt doesn’t hold for F varying with time (very basic maths, Ray, just try and enjoy). That was the main point in my previous post, saying you cannot fix it in the first place, mostly if we’re talking about possible effects of events which occured before the beginning of the ‘plateau’ and of the change. I can’t see why it is complicated. If that point of mine was wrong, you can just say it and show why. If not, why use that model assuming a constant F?

    Basically, I still can’t see any reason to believe the marked increasing in solar magnetic intensity from ~1900 to ~1960 would have no long term effects in terms of surface temperatures trend in the following decades. Or that this means only about 2 decades or less after 1960 — why? How about dividing lambda by 2, or tripling the considered heat capacity? (ref.#1 / your figure). Practically, are ocean so quick to answer (to show it at the surface)?
    And, even if we drop the long term trend in the signal prior to ~1980, just because we’re expecting for some damped response to a staircase doesn’t mean we can directly compare it to the actual ‘global temps’, forgetting ENSO signal (at least) (ref.#2 / your figure).

    What I’m questioning? Just asking for a proper explanation of the statement in your thread, the one I’ve quote plenty of times, and which I thought should be trivial if you say ‘Of course, …‘. I’m afraid it’s not, not at all. And those basic logical mistakes don’t help believing you’re that easy with the reasonning underlying your statement.

    I’m not the one people expect to properly test historical stories — if you know papers, ouf yours or others, with clear results to appropriate modelling, please give links. Neither do I claim any catastrophic future climate and effects. Of course I won’t take guarantees, here. So I’d be sorry to be left with yet another ‘believe us, we’re experts‘.

    [Response: Again you convert your own inability to follow logic, or mathematics, into a condemnation of people trying to explain things to you. No-one here has ever said “believe us because we are experts” and I have certainly not done so anywhere in this thread. Whether you believe me or not is pretty much irrelevant, but you owe it to yourself to make that determination on something other than your own ignorance on how to solve linear first order ODEs. If you want to solve for the case where F=F(t), the solution is easy to write down:

    T(t)=(1/c) e^{-\lambda t/c} \int_0^t F(t)e^{\lambda t/c} dt

    you need to solve it numerically, but that is easy enough in the computer language of your choice. No amount of fiddling with the coefficients will transform the CR history into anything resembling the temperature history of the last 50 years for all the reasons given above. But this is the joy of mathematics – you don’t need to believe me. Work it out for yourself. And then, when you come to the same conclusion that I did, come back and say so. Of course, if you come to some different conclusion, tell us that too (though this is rather unlikely I would wager). You basically only have two choices – trust what experts say or investigate the mathematics it yourself (and this is not rocket science). Distrusting what an expert says without a basis of any actual work is simply an exercise in bias confirmation and not in the least bit interesting. – gavin]

  16. 216
    Samium says:

    Do you seriously believe I didn’t do that same job myself before questioning you, Gavin?

    you need to solve it numerically, but that is easy enough in the computer language of your choice.

    Seems you’re speaking to a kid… Sorry, I in turn suggest a bit more courtesy.

    I’ll continue this response tomorrow (it’s getting late, here in France, and I’d rather use my own computer for that).

    [Response: If you’ve done it already, then why are you wasting everyone’s time playing games? “quand je suis devenu homme, j’ai aboli ce qui était de l’enfance”. – gavin]

  17. 217
    Samium says:


    Here you are.

    I don’t think any comment is requiered. Or do I need to remind us that you allowed me to play with the parameters, hypothesis and history for what concerns the physics as long as we don’t have any increase in the GCRF possibly-induced forcing after the beginning of our ‘plateau’ (as you can see, I even considered a small decrease after ~1960)?

    Only a few precisions could be usefull for the other readers, who may not have read our previous exchanges:
    – if you conclude that I may have tortured the parameters, Gavin knows it’s not the point, here (see e.g. his last comment in my post above);
    – Gavin, it seems, add no real objection to the fact I intended to rely on a (coarse) correlation between GCRF and 10Be;
    – if you notice ENSO non radiative forcing (and whatever forcing) are not modelled, here, it’s perfectly normal: also part of the hypothesis (i.e. the model proposed by Gavin). And of course, no one would pretend this model intend to predict the actual ‘global temp’ anomaly.

    So Gavin, as I said, I’m still waiting for a proper explanation of the reasons allowing you to write down: “Of course, to show that cosmic rays were actually responsible for some part of the recent warming, you would need to show that there was actually a decreasing trend in cosmic rays over recent decades – which is tricky, because there hasn’t been).

    PS: last time, Gavin, you’ve censored a post of mine (the only one, very gentle case) certainly because I’d added a comment in French (to someone adressing one to me in French). It’s OK (I understand you would reject comments that moderators may not undertsand), but is it fair to send another non courteous one to me in French?… Could you please drop that kids story?

    [Response: Chapeau! (at least for effort). But no cigar. You have confused [tex]\lambda[\tex] with it’s inverse (look at the dimensions in the equation), and hence you have assumed a sensitivity of over 10ºC to doubled CO2! The scaling for the forcing you have chosen (a decrease of 53% in the 10Be concentration from Dye3 gives 0.3 W/m2 forcing) is a very small effect, but a huge sensitivity can magnify the impacts of that. Doing your exact calculation with the [tex]\lambda=1/0.35[\tex] you intended to use, gives a warming in the 1980’s of ~0.11ºC. Applying this to the Oulu CR record (and assuming that % decreases in CR can be scaled directly to 10Be in Dye3 (dubious for a number of reasons, but let’s ignore that for now)), one can calculate what the response would be to the actual CR changes since 1964 would give a net change of a maximum of 0.016ºC. It’s worth noting that the lambda is pretty much irrelevant to this since there is no big long term trend in the CR records.

    But even aside from your mis-specification of the sensitivity, your choice of baselines used for the zero point in the forcings and temperature are odd. You used the single high 10Be point around 1893 as the zero, which gives a net forcing over the whole record of around 0.2 W/m2. The long term mean 10Be concentration at Dye3 is around 1.05 (10^4 atoms/g), would be a better zero point, or the average over the 19th C perhaps (but that’s the same). This would reduce the forcing by half – but of course, you could rescue your result by having a sensitivity of 20ºC. – gavin]

  18. 218
    Samium says:

    (I took the first site I’ve found to upload my graph… Feel free to upload it elesewere).

  19. 219
    Gordon Jenkins says:

    I have a textbook to read. I hope it talks a little bit about Isotope tracing and marking. ( I’d also like to know more about Isotope Geochemistry ( and Volcanic Gas
    ( or Vog
    ( as pre-anthropogenic contributors in the natural cycles of climate change. I like volcanoes, they are big and smokey.

    Re-Gavin’s Response: 1 Corinthians 13:1-13 -ἀγάπη in full context.
    “Omnia vincit amor, et nos cedamus amori” -Virgil, Eclogues X.69

  20. 220
    Samium says:


    once again, you’re just moving your defence line… and still haven’t bring support to that claim of yours we’re discussing about till the beginning.

    Last but one, you’d said:

    No amount of fiddling with the coefficients will transform the CR history into anything resembling the temperature history of the last 50 years for all the reasons given above. But this is the joy of mathematics […]

    Now, interestingly, your new objections are all about discussing the values I fixed for the said coefficients.

    As for the offsets, why would we care for such an analysis, dealing with only one ‘forcing’ out of many (when known) and temps ‘anomalies’ (give it another name when ‘offset’, if you like).

    However, thanks for pointing my big mistake on λ (why do climatologists use the same letter both for one thing and the reverse? I’m not seeking any excuse for that, just explain why I didn’t check that.)

    So OK, fixed: I’ve made this new graph.

    – Of course, the post-1960 temperature trend gets lower. Yet it’s not null — needless to say?

    – With λ = 0.6, we get +0.12°C. Not bad… (and you’d get ~0.20°C with a doubled c — why not?)

    – I added a 2nd hypothesis for past-1960 forcing, based on reference I’ve made twice in the discussion, indicating a GCRF trend of around -4% from ~1962 to ~2001 but ~0% when considering the period ~1962 to ~2009. Of course, we get higher temperature trends (up to ~2005) when we account for that.

    – In order to allow the comparison to get some meaning, I thought I’d rather change the hypothesis on F before 1960 and consider some very simple function.

    hence you have assumed a sensitivity of over 10ºC to doubled CO2

    Of course I’ve not assumed anything about the effects of CO2…

    [Response: 2xCO2 forcing is ~3.7 W/m2. Therefore any assumption about \lambda implies something about the response to 2xCO2 (and if you want to argue about that, do it with someone else). But you’ve demonstrated my point – none of your temperature timeseries resemble the observed trend. All asymptote over the last 50 years just as I claimed above (and indeed demonstrated in a simple case). And your argument would be in even worse shape if you took the 10Be from NGRIP or South Pole to link to the CR NM data. – gavin]