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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. 151
    Richard bird says:

    CM : re your correction on nucleation as distinct from cloud formation: I think looking at the CERN press release you will understand how easy it is to read the simple message “ionisation = more clouds” into it.
    “unprecedented insight into cloud formation”
    “cosmic rays enhance the formation rate by up to tenfold or more..”.
    Not an excuse, just an observation.

  2. 152
    Richard bird says:

    Hank turner: re Co2 ice , I realise i should have been clearer. By “higher altitude” i meant high in the atmosphere. To be precise, would there be a chance of co2 molecules in the air at high altitudes clumping into crystals, large enough to prompt cloud formation, either at high altitude or as a result of falling to lower altitudes.

    The obvious gist is that this would have two effects , more cloud, and removal of some of the greenhouse effect.

    As you can see I tend to look for possible self regulatory mechanisms in the atmosphere and biosphere. The biosphere has evolved for long enough to have perhaps developed mechanisms yet to be discovered. sure it sounds like the Gaia theory, but as a result of natural evolution. don’t ask me to enlarge any more than that please, it’s just a thought not a theory!

  3. 153
    Richard bird says:

    So sorry. I see the post is from Hank Roberts not Turner My slip of the finger.

  4. 154
    CM says:

    Theo #150 (Mars) — Ah, I didn’t think about that. Hank #148 — great links. Thanks. Not only are there no heretical questions, there are none that cannot throw up something new to learn.

    Richard #151 — The press release was pretty straight, really, but you were probably primed to understand it that way by a decade of solar-GCR-climate hype. All the more reason to read this RealClimate post carefully.

  5. 155

    #152–No, anywhere in the atmosphere where there’s enough water to form clouds is too warm to freeze CO2.

    And actually, since in the stratosphere the lapse rate turns negative–ie., temps start to increase again as one ascends–I doubt there’s anywhere in the atmosphere where CO2 actually will freeze at all, just off the top of my head. Combination of temps being too high and pressure too low.

  6. 156
    Pete Dunkelberg says:

    Jeff S. @ 149, maybe this will help:

    An Even Cloudier Outlook for Low Climate Sensitivity, and see that site for Lindzen generally.
    We also know from Paleo evidence that clouds do not spring to the rescue and nullify positive forcings.

  7. 157
    Richard Bird says:

    Theo 150 – I missed your post – Thanks for the reply. You read my question correctly – re Co2 crystal formation in the upper atmosphere. So perhaps it snows CO2 on Mars, a nice image? Presumably over Earth the absolute temperature is not the sole problem, as it will get close to 3-4 degK eventually, but by then if I understand physics correctly the gas pressure is far too low to consider any solidification? If so, pity, it would have been a neat example of natural feedback – another one for the waste bin.

    CM – I wonder why you call it a decade of hype. Is it not ten years of legitimate scientific enquiry? There must be 99 discarded hypotheses for every successful one. If those researchers attracted to the Svensmark/Shaviv/Kirkby theories (yes I have been primed by the hype!) believed they were onto something useful to advance knowledge, it seems fair to give them benefit of doubt, until observations are checked and the theory either confirmed adequate for purpose or falsified. I can understand people getting a bit too enthusiastic about their ideas, and perhaps overstating their case, but would that be hype? On the other hand, I have only been studting the CLOUD programme and its theoretical basis for a few weeks so perhaps I have missed out on the hype.

    But I do agree with you that hype is any form is best avoided. (Although it does produce some very entertaining blogs elsewhere!)

    I must say the CERN CLOUD chamber looks like a superb precision equipment, useable for all kinds of future experiments.

    I am sure this must have come up before, if so apologies for being boring and feel free to send me off to some other place: If CO2 levels have been constant at 280ppmv until the onset of industrialisation, how does climate science account for the so-called Medieval Warm Period and Little Ice Age? Is there any evidence of CO2 variation causing those changes (which according to what I have read so far were global, not just local)? If not, how are they explained?

    Thanks in advance for the very helpful replies.

  8. 158
    dhogaza says:

    Richard Bird:

    it seems fair to give them benefit of doubt, until observations are checked and the theory either confirmed adequate for purpose or falsified.

    One problem, of course, is that not only do they propose a totally unknown mechanism for GCRs modulating climate, but they have failed to adequately explain while everything we know about the physics of CO2 and long-wave infrared radiation is wrong … really, you’d be better of learning science from legit sources of science rather than the denialsphere.

    If CO2 levels have been constant at 280ppmv until the onset of industrialisation, how does climate science account for the so-called Medieval Warm Period and Little Ice Age?

    Sounds to me like you’re buying into yet another denialist meme, i.e. climate science insists that only varying CO2 levels can affect climate.

    Is there any evidence of CO2 variation causing those changes (which according to what I have read so far were global, not just local)?

    More proof that you’re getting your information from the denialsphere, rather than science.

  9. 159
    Joe Cushley says:

    Re: yes, this is boring, Richard. ‘What you’ve read so far’ is obviously denialist clap-trap. As I said, Start Here button, and come back when you’ve got a grasp of the very basics.

  10. 160
    Hank Roberts says:

    > Richard bird
    > By “higher altitude” i meant high in the atmosphere.
    Read the link I gave you all the way to the bottom; understand how both altitude and “partial pressure” work — your answer is there.

  11. 161
    Hank Roberts says:

    Did anyone find the answer to the questions (the inline reply) for Forrest Mims there? I don’t think he’s come back to answer them, and I couldn’t find that he’s published what he posted here. Perhaps he was challenging the readers to take the data source he named and do their own statistics?

  12. 162
    Bengt A says:

    What’s your say on this one? A paper that seems to confirm the findings in Svensmarks paper on Forbush decreases (2009). From the conclusion …The result strongly supports the idea that cosmic rays influence the atmospheric processes and climate…”

  13. 163
    CM says:

    Hank #161, re: the Oulu trend claim and Eric’s inline question at #88

    I’ll hazard a guess. His $y$ is the Oulu neutron count rate, the unit of his $x$ is months, and he did an OLS fit to the monthly data. (Doing the same I get $y = 0.3812x + 6032$, pretty close to what he reported, though I’m not sure why I can’t reproduce it exactly). Eric’s right, of course, but if one uses the monthly data and ignores the high auto-correlation, one can fool oneself the trend’s significant at the 99.9% level… With annual data, no trend.

  14. 164
    CM says:


    Sure, how cosmic rays may affect cloud is a legitimate scientific inquiry. There is no contradiction with saying that it’s also been wildly hyped e.g. as “a new paradigm of climate change… already at least as secure, scientifically speaking, as the prevailing paradigm of forcing by variable greenhouse gases”(from Svensmark’s 2007 article “Cosmoclimatology”). See also his press releases, Calder’s book… CLOUD seems to have shaped up nicely from such beginnings.

  15. 165
    Richard bird says:

    CM , thanks. I had not seen that Svensmark quote or reference. I understand your viewpoint re hype. I have read Calder’s book though. As a layman that was persuasive re a possible link with solar activity etc. I am not equipped to comment critically on it of course. But it did not seem to make a sound case to ‘deny’ co2 forcing, simply introduce another possible element in the picture.

    Perhaps one of the interesting aspects (to me) of the CLOUD result is the possible role of organic compounds. As my post 152, this seems to endorse the question of whether the atmosphere should properly be considered as part of the biosphere. An interesting line of research?

    I will defer from any more general climate change questions here as it is clearly not the place.

  16. 166
    Rodolfo Graziani says:

    Moscow neutron monitor seems to show a clear downward trend

    [Response: That website is not up to date and doesn’t show any recent data, this site is better and is what I used in this figure. – gavin]

  17. 167
    CM says:

    Bengt #162, re: Dragić et al. (2011) Forbush/cloud paper,

    Hm, another paper which (like Svensmark et al., 2009) sees effects on cloud from sharp drops in cosmic rays (Forbush decreases, FDs) when considering only FDs above a certain cutoff value. Some other papers have found little or no connection (Kristjánsson et al., 2008; Calogovic et al., 2010), so this is an ongoing debate (see comments by Jeff Pierce upthread).

    Dragić et al. offer two new twists that I can see: First, they use diurnal temperature range (DTR) as a proxy for cloudiness. It gives them a longer, and perhaps sturdier?, record to work with than the satellite data other use. This sounds clever. Is DTR a good cloud proxy?

    Second, they use something called superposed epoch analysis (SEA) to tease out a connection. Googling a bit, I get the loose idea SEA is an established method for this kind of thing, but that significance testing can be problematic and t-statistics may not be the best approach. But this is Greek to me and I could be totally barking up the wrong tree. Anyone in the know care to comment?

  18. 168
    Bengt A says:

    CM #167

    Yeah I agree with you on the use of DTR (Diurnal Temperature Range). It seems to be a more robust indicator than satellite data on cloudiness etc. A broader time span with more Forebush decreases to analyze also results in a better signal/noise ratio.

    I have a hard time finding any flaws with this paper. In my opinion it overtakes all the papers you mentioned (Svensmark, Kristjánsson and Calogovic) due to the method used and the broader time span. Pretty convincing, isn’t it?

  19. 169

    #165–“I will defer from any more general climate questions here as it is clearly not the place.”

    Well, maybe better on the open thread than the CERN thread.

    But RC is in general a good place to get answers to ‘general climate questions.’ What’s putting some folks off is the framing of many of your questions so far. (There is a long and tedious history of ‘concern trolls’ which helps shape this dynamic.) Reading some of the intro stuff under the “start here” heading, as has been recommended before, should help you to develop alternate questions and alternate ways of framing your questions–in short, should afford you a wider perspective. (Perhaps you’re already doing so.)

    Your question at #157 is a good illustrative example. You may well have offered your question about CO2 forcing in the MWP, and its accompanying “presumption” about its global extent in perfectly good faith.

    Yet as dhogaza wrote, the presumptions 1) that mainstream science ascribes all climate changes to CO2, and 2) that the Medieval Warm Period (or “Optimum” or “Climate Anomaly” was global in extent are common denialist themes–ones debunked and rebunked frequently, and which have consequently acquired the name of “zombie arguments”–arguments dead, but still walking. Hence the suggestion to read some other sources before asking questions (which may well be, shall we say, overly familiar to some.)

    One good ‘alternate source’ for your specific question would be Mann et al (2009.) The abstract says:

    Global temperatures are known to have varied over the past 1500 years, but the spatial patterns have remained poorly defined. We used a global climate proxy network to reconstruct surface temperature patterns over this interval. The Medieval period is found to display warmth that matches or exceeds that of the past decade in some regions, but which falls well below recent levels globally. This period is marked by a tendency for La Niña–like conditions in the tropical Pacific. The coldest temperatures of the Little Ice Age are observed over the interval 1400 to 1700 C.E., with greatest cooling over the extratropical Northern Hemisphere continents. The patterns of temperature change imply dynamical responses of climate to natural radiative forcing changes involving El Niño and the North Atlantic Oscillation–Arctic Oscillation.

    In other words, the the Medieval Warm Period was 1) not globally homogenous, and 2) likely due to natural variation (not CO2 change.) So that’s one answer to your questions in #157.

    It’s only one paper, of course–albeit an influential one–and the MWP/MO/MCA and the LIA are much-studied topics. Google Scholar is a great tool to find out more:

    (“Much-studied” in this case means 59,000+ hits. One way to assess the importance of all these results is to look at citations–how much has a given paper informed subsequent work. Mann et al (2009) shows 95 citations on the search page, which is not bad for a two-year old paper. For context, the original ‘hockey stick’ paper from 1998 shows 1214 citations–which is presumably why denialists are still attacking it as though no subsequent work has been done on the topic.)

    As an aside and a hat tip, Hank Roberts has been a model for me in doing one’s own legwork generally, and of the utility of Google Scholar in particular. (Also of the utility of your local reference librarian!) I think that he’s absolutely right that most of us tend too much toward a passive attitude to information. (Yes, I mean me! I can’t tell you how many times I’ve caught myself in this attitude and decided “You know, I should really look this up myself.”)

    Of course, you can’t treat everything you look up as received truth. That would be just pushing the passivity back one level, and there’s a lot of nonsense out there–some of which is not *obviously* nonsense, at least for the general reader.

    Once in a long while you turn up something worthwhile (even for the moderators here!) that has flown under the radar, and in doing so serve the whole community.

  20. 170
    CM says:


    (Looks like I spoke too fast: I see it’s not the first time DTR has been used to test a GCR-cloud connection; here’s one paper that apparently took this approach and came to opposite results.)

    I think I’ll wait to hear what the experts have to say about Dragić et al. Meanwhile, I’ll just take it at face value as giving some support to the existence of a GCR-cloud mechanism.

    At the same time, ironically, it confirms that the recent global warming cannot be attributed to cosmic rays, since the DTR fingerprint is wrong. Don’t expect the deniers to get it, though.

  21. 171
    Bengt A says:

    CM #170

    What do you mean by … since the DTR fingerprint is wrong…? As far as I understand the hypothesized process, the fingerprint is correct. A Forbush decrease causes less cosmic rays, less aerosols, less cloudiness and an increase in Diurnal Temperature Range. That is what I see in Dragic paper in fig 3 and 5. Or are you referring to the Balling & Cerveny paper?

  22. 172
    Richard bird says:

    Kevin McKinney: thank you for a helpful, reasonable, detailed and courteous reply. I have noted all your points. Specific answers to specific questions are all I would wish for.
    Re reading up on the subject: there are many environmental issues in the world, and climate is just one of them. As for reading to date, my starting point was the entire IPCC Working group 1 report ‘The physical science basis’ and some sections of other ipcc reports. Also most wikipedia articles on climate, climate change, car on dioxide, global warming, greenhouse effect etc. I have of course trawled the web and clearly there is a lot of hot air out there, from all angles. I am not competent to judge the quality of the science within climatology, which is clearly a very complex field of study, but like most people I expect to see correlation of facts with theory. One problem with that is getting a clear picture of the ‘facts’ amongst the hot air, and knowing which sources to trust.

    Google scholar is a new site I will look into it. But essentially, there is just not enough time in the day. Certainly not enough time to take a course in climate science. That is why if a question arises in my mind , and the answer is not readily available, I have put it here, on the assumption that there may be a simple answer from experts in the field.

    From the wikipedia article (on ‘global warming’) my curiosity was initially aroused when I noted that the ‘Reconstructed Temperature’ Graph which is a fairly common graph, correlated about 90 per cent with the c14 based solar activity graph over the period 900 to 1900. From that point as a side interest I looked into the role of solar activity and of course came across Calder’s book and followed the CLOUD project with interest. I hope that makes me neither a troll nor a ‘denialist’. Just an ‘enquirer’. Thanks again for the help.

  23. 173
    CM says:

    Bengt #171,

    Glad you asked. Yes, that’s exactly how I understand the hypothesized relationship in the Dragić paper. It follows that, if the global warming since the mid-20th century were due to less cloud albedo, due to less cosmic rays, then the diurnal temperature range should have risen as the Earth warmed, just as it apparently went up for a few days after strong Forbush decreases. Do you agree? But instead, it’s gone down (-0.07 °C per decade 1950–2004), as we would expect from greenhouse warming.

    Now, this doesn’t falsify the hypothesized GCR-cloud mechanism — because there hasn’t been a trend in GCR that would allow the mechanism to explain the warming anyway, it’s no surprise that we don’t see its fingerprint on the warming. It just adds to the arguments that we cannot attribute the recent warming to this mechanism, if it exists.

    This is ironic, because IMHO a large share of the solar-GCR-climate-theory fans don’t give a hoot about the mechanism, much less about the other interesting science that is now being turned up by looking for it. They just want the causes of the warming to be outside human control and anything but fossil fuels. Such people will no doubt cite this paper for its overwrought conclusion about a cosmic ray effect on climate (though it’s only looked at weather), but it seems to me that it logically undermines their agenda.

  24. 174
    Jeff Pierce says:

    Bengt A. and CM, thanks for posting those 2 papers and for the discussion on the diurnal temperature data. The data in the new paper look very clean (perhaps due to the longer database of FDs available when using surface temperature measurements as you mentioned). Its hard to deny that SOMETHING is going on.

    On a somewhat related note, I’m at a meeting on solar variability and climate now at NCAR and there has been a bunch of discussion on Solar Energetic Particles (SEPs, these are similar to cosmic rays, but lower energy and come directly from the sun). SEP events may have a pronounced effect on stratospheric chemistry ( that lasts for weeks. This could effect the radiative fluxes to the troposphere, which might feedback on cloud processes. This was discussed in the Calgovic 2010 FD paper (, but I don’t know anyone who has followed up to see how important these effects are.

    Interesting stuff!


  25. 175
    Samium says:

    I was struck by Gavin Schmidt argument:

    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).

    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?

    [Response: Gosh – how silly I must be to think that attribution needs to account for all potential effects at the same time! But your logic is backwards – if potential cause A doesn’t show a change and yet effect B does change, no amount of other potential causes C, D, E or F are going to give you evidence that A influenced B. Yet if potential cause X is changing and yet effect Y is not, consideration of other potential effects might be very important. – gavin]

    Now, 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. At best, he forgot the huge thermal inertia of oceans and every non-linearity in the climate system.

    [Response: You aren’t being rude, just ignorant. – gavin]

    In no way the fluctuations of ‘global temperature’ – if such a thing exists (indeed, this concept lacks physical sense) – or any regional temperature is expected to follow the variations of the radiative fluxes with a given (constant delay), not to mention a short one.

    [Response: If you don’t think that a surface integral of a 3-dimensional field on a sphere makes sense, take it up with Lebesgue. But if you don’t think it exists why do you care how changes in it are attributed? From your presumed perspective I could not think of anything more pointless. – gavin]

    Moreover, the choice of the last 3 decades is very unfortunate. 5 decades would have been even more unfortunate, as the GCR flux trend in the last 5 decades was also null but the satellites ‘measurements’ of temperatures yield only a very small trend (0,14°C per decade) for the last 3 decades.

    Why? Just have a look at this graph, showing the variations of 10Be during the last 6 centuries, as measured in the ice core from Dye-3, Greenland (Beer et al. [1994]). BTW you can compare them to the fluctuations of the solar spots number. It is well known that of 10Be is a good proxy to evaluate GCRs flux (and solar activity which modulates it).

    [Response: So well known in fact that I have co-written three papers on the subject: 2006; 2009a; 2009b. You might care to read them – and note particularly that 20th C trends in 10Be data depend very much on the individual record. – gavin]

    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!

    Which should correspond to a 6% increase in cosmic ray induce ionization according to Shaviv [2005].

    So, even if there is indeed a lot more to demonstrate, there’s nothing shocking at all in the idea that a dramatic decrease of the GCRs flux in the last 3 centuries, followed by a plateau at a very low level (for historical ages) of 5 decades can induce a significant temperature increase having started 150 years or more ago and going on a few decades after.

    [Response: Regardless of whether that is a realistic assessment of the solar forcing, it still doesn’t give you what you want. Put that into any climate model you care to mention and it will not look like the temperature response in the real world. 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. Plus stratospheric cooling (you can go look that one up). – gavin]

  26. 176
    M says:

    “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…”

    Hmm. I do your suggested replacement, and come up with the logic that:

    “Of course, to show that CO2 was actually responsible for some part of the cooling between 1940-1970, you would need to show that there was actually a decreasing trend in CO2 over that time period – which is tricky, because there wasn’t.”

    Huh. That actually makes total sense. CO2 wasn’t responsible for the 1940-1970 cooling. Looks like Gavin’s logic is completely consistent…

  27. 177
    Ray Ladbury says:

    Samium, I’m really wondering how you pull it off, being so utterly ignorant and arrogant in the same post. Impressive!

  28. 178
    Hank Roberts says:

    > Jeff Pierce
    > … I’m at a meeting on solar variability and climate now at
    > NCAR and there has been a bunch of discussion ….

    Thank you!

  29. 179
    Samium says:


    thanks for your response, but I can’t see any direct answer or clear explanation in it. In fact it’s getting more and more obscure. I’ve used a very simple argument, whereas your answer either satisfies with saying “nonsense” (why?) or enters bits of explanations, even listing “hints” — as for checking if the real world shows the “good” behavior using models, of course I won’t.

    Perhaps I was not clear enough (sorry, I’m French, doing my best with English) or even a bit too complicated for some readers, so please let me use a very simple image this time.

    Imagine you’re having a bath. At any given moment, you adjust the tap so that the water flow is at a given level, which you maintain for 50 seconds. What you are saying is that, during this 50 s period, due to the fact that the flow is unchanged, obviously the water level in the bath won’t rise… See? Of course, here I’ve supposed the drain was closed, whereas we should reason with both tap and drain opened, considering the difference between the flows in and out of the bath: if the flow in is larger than the flow out, then the water level rises. Even if the net flow remains constant.

    Excuse-me to come back to the main point: that’s a direct response to your argument. If this is “nonsense” (you’ve said I’ve not shown myself rude, just ignorant) and if your formulation was OK, why go on with developpements about plateau and damping? As you can see, your initial argument told nothing about delay or damping. But once again, my point was about possible mixing of a function and something more homogeneous to its integral (if we had to choose), looking at the way you’ve exposed your argument, i.e. matter-of-factly and without any explanation.

    Besides, you chose to talk about the last 3 decades, not me. Now you’re talking about exponentials and damping, I’m sorry, but looking at the satelites mesurements of temperatures I can’t see only a small trend and no acceleration in the last 3 decades. So what?

    Now, when you remove the 11-year filter, the GCRs flux curve in the last century is everything but a nice slope with a 5 decades plateau at the end. Looking at the 10Be curve, I’d especially note a sharp decrease from 11 500 around 1950 to 7 000 atoms/g around 1960. So when, exactly, should we expect to see a pick in the warming trend. The warming of what, exactly (is obviously a related question)?

    Curiously, a quick look at a “global temperature” curve indicates that it’s been rising quite continuously from ~1965 — the pick I told about was in 1962 for the GCRs flux curve, after what we’ve got our famous plateau. Also curious, “global temperature” had shown a similar rise from ~1910 to ~1940, while the 10Be curve shows a similar sharp decrease between ~1890 to ~1900 (from ~15 000 to ~7 500 atoms/g), after what it has oscillated around 10 000 atoms/g for a few decades.

  30. 180
    Samium says:

    […] attribution needs to account for all potential effects at the same time!

    Of course, but:

    1) I was precisely saying that this doesn’t only holds for CO2 and the period 1940-1970 (or others showing opposite slopes);

    2) once again, before discussing slopes one should not mixing a function and its integral… (Same answer to M).

  31. 181
    Samium says:


    thanks for the links to your studies on 10Be. Of course I won’t be able to make any comment for long, that’s rather complicate. I’ll try and find the time to read that.

    Now, for our purpose, we still have centuries of mesurements for sunspots number, and correlation between them and GCRs fluxes for several decades. So it’s not evident to me that this issue of climate (general circualtion) influences on 10Be concentrations in ice cores is highly relevant to our discussion.

  32. 182
    Samium says:

    One last precision, if necessary:

    in the case of my bathroom scene, it’s perfectly clear that your statement about the rates [being] maximum at the beginning of the ‘plateau’ and decay almost immediately (giving an exponentially slowing warming as you reached equilibrium with the new state) is not what we observe: the rate (here, the water level rising) remains constant for a given value of the net flow.

    One again, it seems to me that the difference has something to do with mixing a function an its integral.

    Maybe you’ll tell me our climate system isn’t a bath. Yet it seems useless to dig in complex stuff if the grounds is mistaken. So excuse-me to insist on this issue.

    [Response: There is no impact of the bath level on the net input. But there is in the climate (the warmer it gets, the more radiation is emitted). The situations are not equivalent. – gavin]

  33. 183
    Samium says:

    True, but:

    1) GCRs flux is not a “feedback” but a “forcing”. Its effect on low cloud cover is maybe temperature dependant, but quite obviously far less dependant than on solar activity;

    2) which brings us back to the question: what about my integral (#179) i.e. the fact that just because our input is on a plateau doesn’t mean the output remain constant?

    BTW, I had a closer look at the “plateau”, in the case of Hermanus (lat. -34,42°) where they have daily mesurements since 1957. After 11-year filtering, it more ressembles to a double plateau, with a first one from 1966 to 1967 and a second one from 1988 to 2003, the latter showing 4,2% less GCRF compared to the former.

  34. 184
    Ray Ladbury says:

    Your ignorance is revealed in several ways. First, you clearly are not familiar with general climate science or even GCR research. If you were, you would know that the idea of anthropogenic warming due to CO2 has been around since 1896, and the basics of it have changed little. Do you really think it is wise to argue for replacing long established science that does an excellent job of explaining the behavior of Earth’s climate over millions of years with a vague, untested conjecture?

    Second, correlation between sunspot number and GCR flux is not that great. GCR flux is also tiny–about 6 particles per square cm per second. Third, GCR fluxes from ~1950-2008 were remarkably stable, and yet, we see marked warming from ~1975 to the present. Moreover, the Solar Minimum just concluded was the deepest since the space era began, and yet 2010 was the warmest year on record? Also, there is no way you get simultaneous stratospheric cooling and tropospheric warming with a GCR mechanism. Finally, the purported mechanism for a tiny flux of GCRs affecting global climate simply doesn’t hold together, as there is no evidence that CCN are the limiting factor in cloud formation.

    However, the most marked sign of your ignorance is your blithe dismissal of the opinions of the experts. This indicates a profound misunderstanding of scientific method. Si vous preferez, on peut continuer en Francais.

  35. 185
    Ray Ladbury says:

    Samium, would you like another straw to grasp. That one is water-logged.

  36. 186
    Hank Roberts says:

    PCR –taking samples of unknown genetic material — then testing against known material to see what matches up — has many uses.

    Climatology applying this method to determine sources of clouds.

    I love the contrast. Physics at CERN — take a volume and super-clean the inside then test very small amounts of known material and see if they produce the cloud nuclei. Conclusion — some unknown organic material must be needed.

    Biology — sample “airborne aerosol, fog, and cloud water” to identify what’s in the droplets.


    Marine microgels as a source of cloud condensation nuclei in the high Arctic

    “… in the high Arctic, marine gels with unique physicochemical characteristics originate in the organic material produced by ice algae and/or phytoplankton in the surface water. The polymers in this dissolved organic pool assembled faster and with higher microgel yields than at other latitudes. The reversible phase transitions shown by these Arctic marine gels, as a function of pH, dimethylsulfide, and dimethylsulfoniopropionate concentrations, stimulate the gels to attain sizes below 1 μm in diameter. These marine gels were identified with an antibody probe specific toward material from the surface waters, sized, and quantified in airborne aerosol, fog, and cloud water, strongly suggesting that they dominate the available cloud condensation nuclei number population in the high Arctic (north of 80°N) during the summer season. Knowledge about emergent properties of marine gels provides important new insights into the processes controlling cloud formation and radiative forcing, and links the biology at the ocean surface with cloud properties and climate over the central Arctic Ocean and, probably, all oceans.”

    doi: 10.1073/pnas.1102457108
    PNAS August 16, 2011 vol. 108 no. 33 13612-13617

  37. 187
  38. 188
    Hank Roberts says:

    A bit of history on the assay described above:
    Marine Chemistry, V83, Issues 1-2, October 2003, Pages 89-99
    Novel Techniques for Chemical Characterization in Marine Systems
    Tracing the source and fate of biopolymers in seawater: application of an immunological technique

    Sorry for the digression. But I do urge the physicists to notice what the biologists are doing here.

  39. 189
    Richard Bird says:

    Hank Roberts. Very interesting line of thought.

    There are approximately 10 million viruses in every drop of surface seawater.

    ‘Scientists discover rain bugs’. Preliminary Press Release

    “In a paper published today researchers in the Manihaha Marine Institute have identified a marine virus which replicates by allowing itself to be transported to the upper atmosphere, where it ‘eats’ CO2, and is returned to the ocean in rain. Comprising less than 150 molecules, the virus, classed as a ‘phage’ is thought to have originally evolved by attacking bacteriaplankton. Marine phages cannot carry out cellular metabolism and must therefore rely on the metabolic machinery of their bacterioplankton hosts to replicate.

    It is thought that around 500 million years ago the particular bacterioplankton host began to die out for as yet unknown reasons. A mutated form of the virus evolved, which was light enough to be carried into the upper atmosphere by ocean evaporation, wave action and air currents. At around 10,000m the air pressure is low enough for the molecular structure of the virus to unwind and to associate with free floating CO2 molecules,methane, water vapour, sodium and phosphorus atoms. It is thought that energy from cosmic rays and ultra-violet sunlight may assist the process.
    The enlarged viral forms replicate by dividing into effectively inert clusters of 50 molecules, hardly distinguishable chemically from common amino acids typically found in rainwater. These are large enough to form condensation nuclei which seed clouds and fall as rain into the ocean, where they re-assemble into the full virus form. It is thought that the virus has played an important role in regulating the earth climate, and may have been one of the main causes for the massive reduction of atmospheric CO2 levels from around 6000 ppmv in the Cambrian period to modern levels.”

    I made that up. Pure fantasy. But real science is here:

    Keep thinking out of the box! A billion years or so of evolution is long enough for nature to come up with surprises. I have been called ignorant, dumb, insane, unable to think up original thoughts and ‘denialist’ in these pages within the space of a week. I might as well be called a deranged Lovelockian fantasist, what the heck.

  40. 190
    Gordon Jenkins says:

    The INCO Superstack, Sudbury, Ontario.

    “The latest project, which captured and fixed Fluid Bed Roaster offgases, came on line in late 2006, further lowering emissions to allow Vale Inco to meet the new 2007 annual regulatory limit of 175 kilotonnes SO2. Since 1970, Vale Inco has reduced overall SO2 emissions by 90 percent and our goal is to further lower annual SO2 emissions to 66 kilotonnes from Sudbury operations by 2015.” -Vale Inco

    A simple, effective Large scale experiment:
    To test SO2 vs. CO2 emissions effects, try emitting equal volumes and/oror masses of both for set periods of time from The INCO Superstack in Sudbury, Ontario Canada, under simalar conditions/wind/temp/humidity, etc. Clean with compressed air between tests. Record all results including satellite images/temp/cloud temp data. Use N2 or no gas at all as a control/baseline. Tabulate the results publish. No Bias, just plain old fashioned scientific data. Repeat as necessary for sigma/statistical control. What could be easier? (Assuming permissions from INCO Vale, Environment Canada, Health Canada, etc, etc.

  41. 191
    Gordon Jenkins says:

    There is also another international science team nearby at the SNO (Sudbury Neutrino Observatory) Lab who could be a valuable resource for any international scientific endeavour at INCO Vale in Sudbury, who are quite familiar with physics.

  42. 192
    Martin Vermeer says:

    > To test SO2 vs. CO2 emissions effects

    Gordon, your fallacy is not unusual I’m afraid. Yes, you can test the effects of SO2 — or any ‘ordinary’ pollutant — in this way. The effects are mostly localized, and then the stuff rains out after a short time. CO2 on the other hand accumulates: it is this that makes it dangerous. It accumulates, spreads around the Earth in a few years time, and becomes well-mixed globally.

    It makes no sense trying to measure the effect of CO2 released by a single plant locally. It’s almost negligible, and completely negligible compared to the global effect of everything released so far (and not transferred into the ocean, another place where it accumulates), which is where the real threat lies.

  43. 193
    Gordon Jenkins says:

    Martin, I’m not entirely convinced just yet. I agree the effects of super chimney tests being localized to within about 240 km (150 miles) at about 100m wide at start to about 50km wide to perhaps below trace levels 250km out. I believe that is one of the features of this simple experimental matrix. To have some minimum level of control against background effects, etc.
    Next I should point out that a super chimney has the potential to partially separate out ground level pollutants, from the subject pollutants. The INCO Superstack in Sudbury, at 380m tall, and the Ekibastuz GRES-2 Power Station, at 419.2m tall (Called “the cigarette lighter” by locals)in Kazakhstan, fit the bill as tropospheric pollutant injectors, to test for albedo ( or BDRF ( and the Callendar Effect. (

    Is it difficult for SO2 to be “rained out” on a mostly clear day? Dispersed, absolutely, but “rained out”? On the otherhand, a Cumulonimbus (Cb) Inculus is not an uncommon sight in the summer skies of Sudbury, and perhaps not impossible in Ekibastuz, Kazhakstan, either. There also brings us to updraft and uptake from the super chimney in the troposphere to stratospheric heights in one fell swoop, even without the benefits of the Hadley, Ferrel, and Polar Cell atmospheric circulations.
    Even the Polar Jet ( in the Ferrel cell has passed by Sudbury on occasion.

    CO2 has a Molar Mass of about 44.01 grams/mol, and SO2 has a Molar Mass of about 64.07 grams/mol, so yes, the SO2 molecule is heavier than the CO2 molecule. SO2 has a boiling point of -10 °C, and CO2 has a boiling point of -57 °C. The triple point of carbon dioxide is about 518 kPa at −56.6 °C. The triple point of SO2 is 1.67kPa at 197.69 °C.

    Are these tests not simple for an open minded scientist? What is to fear, if it is only simple science? Loss of research fun and funding perhap$?

  44. 194
    Theo Kurtén says:

    Gordon: the loss mechanism of SO2 in the atmosphere is not condensation *as SO2* but oxidation into H2SO4 (in the gas phase or in the liquid phase) and subsequent loss (ultimately through some sort of deposition). BTW, it’s the H2SO4, not the SO2, that’s contributing to the aerosol forcing you presumably want to compare to the CO2 longwave forcing. So the SO2-to-CO2 molar mass, boiling point etc comparison you make is correct, but irrelevant. Anyway, as Martin tried to point out, the problem in comparing S and C emission effects is the timescales – the lifetime of SO2 (plus the lifetime of the formed H2SO4 and the subsequently formed or affected aerosol particles) in the troposphere is days to weeks, while the effect of added carbon dioxide on atmospheric CO2 concentrations (note: NOT the same thing as the lifetime of a single CO2 molecule) is decades to (depending on what you are looking at) millenia. So in your chimney test you would get a very big number (local effect from SO2) that needs to be multiplied by a very small number (effective S emission lifetime), compared to a very small number (local effect from CO2) that needs to be multiplied by a very big number (effective C emission lifetime). In principle, the idea is cool – but in practice, you would very likely not be able to measure the required variables accurately enough to get a meaningful comparison.

  45. 195


    Um, Gordon, perhaps the blizzard of irrelevant factoids–say, the triple point of SO2–could be abated a bit? If you are into experimental design, I think that blog sharing is not your optimum strategy to achieve implementation.

    If you’ve proposed any concrete ‘tests’ I very much fear I’ve missed it. (If your #190 was clear to you, I must let you know that it was not to me. What specifically do you propose to actually measure, and how?)

    Just saying. . .

  46. 196
    Brian Dodge says:

    “…if the flow in is larger than the flow out, then the water level rises.” Samium 10 Sep 2011 @ 4:08 AM True, but incomplete.
    As the water level rises, the pressure across the drain orifice increases, and the flow through the drain increases, the same way that outbound radiation increases as the temperature rises. Radiation varies with the 4th power of temperature, flow varies with the square root of pressure (and is complicated by differences between laminar and turbulent flow).

  47. 197
    Gordon Jenkins says:

    Yup, triple points not relevant, I got carried away. I have a few more factoids to unleash, to slowly get to some sort of point.

    The Total Molecular Mass of Dry Air is approx. 28.97 grams/mol. There is of course wiggle room with this number, being a composite of many molecules. If the air becomes more humid, H2O assumes a greater percentage and a higher ranking, the Molecular mass of H2O is about 18.015 grams/mol.

    Diatomic Nitrogen has a molar mass of about 28.01 and Diatomic Oxygen has a molar mass of about 31.99 grams per mol.

    H2SO4 has a molar mass of about 98.079 g/mol.
    H2S, however has a molar mass of only 34.08 g/mol in comparison to CO2 at 44.01 grams/mol. If CO2 stays aloft for decades and millenia and only accumulates in an atmosphere that is much lighter and boyant CO2, what then of poor old Hydrogen Sulfide, with its lowly molar mass of only 34.08 grams/mol? Now these nasty factoids are starting to take on some contextual import are they not? You may ask, where does this H2S stuff come from? I might also ask where does this heavy strawman, H2SO4 come from? No doubt, you’ll want to throw in the featherweight of Carbon Monoxide coming into the fray with a molar mass at 28.01 grams per mol?
    How about puny but potent Methane at 16.04 grams/mol?

    Yes, it’s all up in the air, until some scientist comes up with a plan to ref this molecular free-for-all. Dammit Jim, I’m a blogger not a scientist! However, I do wish to inspire a search for scientific truth, by offering some thought experiments in the malay of credibility challenges. What do you bring here?

  48. 198
    Hank Roberts says:

    > CO2 stays … what then of poor old Hydrogen Sulfide
    As others have already pointed out, it reacts.

    It reacts _quickly_.

  49. 199
    Ray Ladbury says:

    Gordon Jenkins, Um, did you think maybe to consider how reactive a gas migt be? I mean H2S can only stay in the air as long as it is H2S and not some product of a reaction involving H2S.

    Dude, I assure you. Scientists have worked this out.

  50. 200
    Hank Roberts says:

    “Jon Gordon Jenkins”?