Role of sulphuric acid, ammonia and galactic cosmic rays in atmospheric aerosol nucleation
* Jasper Kirkby,1
* Joachim Curtius,2
* João Almeida,2, 3
* Eimear Dunne,4
* Jonathan Duplissy,1, 5, 6
* Sebastian Ehrhart,2
* Alessandro Franchin,5
* Stéphanie Gagné,5, 6
* Luisa Ickes,2
* Andreas Kürten,2
* Agnieszka Kupc,7
* Axel Metzger,8
* Francesco Riccobono,9
* Linda Rondo,2
* Siegfried Schobesberger,5
* Georgios Tsagkogeorgas,10
* Daniela Wimmer,2
* Antonio Amorim,3
* Federico Bianchi,9, 11
* Martin Breitenlechner,8
* André David,1
* Josef Dommen,9
* Andrew Downard,12
* Mikael Ehn,5
* Richard C. Flagan,12
* Stefan Haider,1
* Armin Hansel,8
* Daniel Hauser,8
* Werner Jud,8
* Heikki Junninen,5
* Fabian Kreissl,2
* Alexander Kvashin,13
* Ari Laaksonen,14
* Katrianne Lehtipalo,5
* Jorge Lima,3
* Edward R. Lovejoy,15
* Vladimir Makhmutov,13
* Serge Mathot,1
* Jyri Mikkilä,5
* Pierre Minginette,1
* Sandra Mogo,3
* Tuomo Nieminen,5
* Antti Onnela,1
* Paulo Pereira,3
* Tuukka Petäjä,5
* Ralf Schnitzhofer,8
* John H. Seinfeld,12
* Mikko Sipilä,5, 6
* Yuri Stozhkov,13
* Frank Stratmann,10
* Antonio Tomé,3
* Joonas Vanhanen,5
* Yrjo Viisanen,16
* Aron Vrtala,7
* Paul E. Wagner,7
* Hansueli Walther,9
* Ernest Weingartner,9
* Heike Wex,10
* Paul M. Winkler,7
* Kenneth S. Carslaw,4
* Douglas R. Worsnop,5, 17
* Urs Baltensperger9
* & Markku Kulmala5
* Show fewer authors
There must be a joke that starts “How many physicists does it take to write a paper?”
Atmospheric aerosols exert an important influence on climate1 through their effects on stratiform cloud albedo and lifetime2 and the invigoration of convective storms3. Model calculations suggest that almost half of the global cloud condensation nuclei in the atmospheric boundary layer may originate from the nucleation of aerosols from trace condensable vapours4, although the sensitivity of the number of cloud condensation nuclei to changes of nucleation rate may be small5, 6. Despite extensive research, fundamental questions remain about the nucleation rate of sulphuric acid particles and the mechanisms responsible, including the roles of galactic cosmic rays and other chemical species such as ammonia7. Here we present the first results from the CLOUD experiment at CERN. We find that atmospherically relevant ammonia mixing ratios of 100 parts per trillion by volume, or less, increase the nucleation rate of sulphuric acid particles more than 100–1,000-fold. Time-resolved molecular measurements reveal that nucleation proceeds by a base-stabilization mechanism involving the stepwise accretion of ammonia molecules. Ions increase the nucleation rate by an additional factor of between two and more than ten at ground-level galactic-cosmic-ray intensities, provided that the nucleation rate lies below the limiting ion-pair production rate. We find that ion-induced binary nucleation of H2SO4–H2O can occur in the mid-troposphere but is negligible in the boundary layer. However, even with the large enhancements in rate due to ammonia and ions, atmospheric concentrations of ammonia and sulphuric acid are insufficient to account for observed boundary-layer nucleation.
What is the boundary layer of which they speak?
Comment by Pete Dunkelberg — 24 Aug 2011 @ 2:14 PM
It seems like steps 1-3 are pretty well demonstrated by Forbush Decrease studies that show a short term rapid changes in solar activity producing an impact on cloud cover. Are you suggesting that the sun is impacting cloud cover through a mechanism other than cosmic rays?
“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).
I understand that the CLOUD experiment considered temperatures down to –25C which is equivalent to only about 20000ft or 6000 metres altitude.
Given that clouds exist at all altitudes up to the tropopause, (and even above in some circumstances) where the temperature is typically –56C and below, are you suggesting that only low, near-surface clouds can affect albedo? Surely high altitude clouds cannot be discounted?
[Response: The comparison being made in the figure was to boundary layer clouds - and so -25 C is unrealistic. It might well be that mid-troposphere comparisons would be better - but you would have different H2SO4, specific humidity and pressure so it is not obvious that what they have now is relevant to real world mid-trop values. Your larger point is well taken - there is no magic rule that says that this mechanism can only work for low clouds - one might expect impacts all through the atmosphere as a function of all these inputs (GCR (higher aloft and near the poles), H2SO4 higher in polluted regions near the surface, temperature etc.). This is precisely the reason why one cannot automatically assume that the net radiative forcing would be negative (remember higher clouds have a significant greenhouse impact). - gavin]
Just a few broad questions related to the potential GCR/Cloud relationship in context of overall longer-term climate modulation:
1) Does this provide yet one more potential explanation of the causes of the Little Ice Age? Though the Maunder Minimum has long been suspected as related at least in part to the cooling seen during this period, the lower TSI in and of itself, was never enough to provide such a cooling, so would a tighter connection between the slightly lower TSI of the Maunder (and hence higher GCR) provide a bit more of a mechanism for the period?
[Response: Undeteriminable at this stage because we don't actually know the impact on real clouds, or what the net radiative effect might be. It could even be positive (since colder areas are more sensitive to CR, and high clouds have a net warming effect). But see too the last post - MM TSI is also uncertain so whether it is or it is not sufficient is unclear. - gavin]
2) Related to question 1), what implications are there for judging the relative strength of the forcing from periods of higher GCR’s versus higher CO2? This question may indeed come back to aerosols, as perhaps a combination of higher volcanic activity PLUS increased GCR’s, is far more potent in providing cooling. Meaning that, each period of low solar activity, such as the Maunder, must be looked at in the overall context of other factors, with aerosols playing a pivotal role in determining the potency of effect. I think about this question more on the very long term scale as well, as the solar system in traveling around the galactic center, may pass through dustier areas or periods of higher GCR’s, and the combination, when occurring at the same time, could provide extra aerosol boost to making clouds.
[Response: None as yet because you don't know the sign or the magnitude of the radiative forcing, let alone how much GCR shielding exists in the rest of the galaxy. This just ends up being unconstrained speculation. - gavin]
On a related topic, Palle et al 2004 explored changes in earthshine-determined albedo, concluding that albedo fell by ~0.02 from 1985 to 1997, then rose by almost the same amount until 2003 when their data series ended. How useful is this technique?
[Response: Compared to the ERBE/CERES data it doesn't appear to be accurate enough to be useful. - gavin]
vboring: I believe that the Svensmark FD paper does show a strong connection between cosmic rays and clouds (and some aerosol properties too) that is hard to have happened by chance. I had to repeat some of the analysis myself to believe it (having already published a paper that found that the CCN should not be greatly changed by cosmic rays).
However, we don’t know what physical pathway connects cosmic rays to clouds. The aerosol nucleation/CCN pathway is the one that CLOUD is currently testing, the one I have explored and the one that has generally gotten the most attention. However, there are other ways cosmic rays and clouds might be linked, although we know even less about them. This paper (http://www.sciencemag.org/content/298/5599/1732.abstract) is a nice overview.
Unfortunately, until we fully understand these physical links, it is difficult to predict how cosmic rays may have changed climate. And as Gavin says above, there really hasn’t been any trend in cosmic rays in the past 50 years.
“… observed correlation between cosmic ray intensity and Earth’s average cloud cover over the course of one solar cycle….” (Carslaw et al. 2002)
What, if any, intervening variables have been thought about? Have any been eliminated? (Blue-skying, I wonder if plankton DMSO production varies (the quantity, or the dominant species, or ???) with the solar cycle, perhaps correlated with changes in the amount of UV getting through to the ocean surface.)
[Response: Your moscow data only goes to 2006 - more up-to-date data here. I will plot it on the same graph and link it here. There are minor differences in the neutron monitors that depend on latitude, pressure corrections, sensitivity, but they are all very highly correlated. There is no significant long term trend. - gavin]
Plenty more there. I know this must be well discussed somewhere (pointer welcomed). It’s just the one mechanism I happen to have heard about, that seems likely to be able to multiply a little variation in solar influence greatly over a few years, given how fast plankton populations can boom.
Makes more sense to me than pure physics explanations for changing cloudiness. But, then, I was raised by and among biologists ….
Gavin: I don’t understand what is unrealistic about 25 below C, unless you live down south. I have been outside in central Iowa when the straight temperature was 40 below. -25C = +13F. 25 C below is no big deal. Actually, +13 degrees F is fairly warm. The sky can be gray at that temperature. In western New York state, 40 below is too cold for snow, but that doesn’t mean the ceiling is unlimited.
Your CV says you are from Oxford, England and New York City. NYC is south of my home town, but not that far.
13 Jeff Pierce: Why don’t I see cosmic ray tracks on foggy days? Did the charged pion beam make a cloud that looked like a beam?
“All measurements were made at 38% relative hum”idity. Why were the experiments done at such a low relative humidity?
Eli: the nucleation process in itself probably doesn’t involve or need NOx, but growth to larger (e.g. climate-relevant) sizes almost always needs condensable organic vapors, and their formation usually involves NOx one way or the other. And of course NOx affects oxidant concentrations, which also drives the production of H2SO4 – but this is still different from actually directly participating in the process. (From a regional modeling viewpoint, the difference between nucleation and subsequent growth might not be that big, but it certainly is for us nucleation modellers!)
Hank: in addition to DMS, algae also likely emit nitrogen-containing bases (like amines) which are also important for particle formation. Continuing on your blue-sky hypothesis, these emissions could conceivably also be dependent on UV.
True, but there is downward trend in the period 1966 to 1996, when a lot of warming took place. What happened after is a climb in the neutron count, which might explain the lack of gain in ocean heat after 2003.
18 Edward Greisch: You cannot visibly see the effects of cosmic rays with your eyes. Clouds are not instantly formed when cosmic rays form ions in the atmosphere, which is a good thing since cosmic rays create more than 10 ion in every cubic centimeter of air each second (we’d be engulfed in thick clouds all of the time!). The ions from cosmic rays aid in forming aerosol particles that are too small too see. These particles may eventually grow (over the course of several days) by condensation of sulfuric acid and organic vapors to be large enough for a cloud droplet to form on (even then a cloud droplet will only form when the air becomes saturated with water vapor, and this needs to happen independently of these other processes).
Thus, the pion beam did not make a cloud that looked like a beam. In fact, no clouds were formed during these experiments at all (as you point out, the RH was ~38% and you need to reach >100% RH to form a cloud). These cloud experiments only tested the very first step of this cosmic-ray/aerosol/cloud hypothesis (the aerosol nucleation step). There are plans in the future cloud experiments to test the other steps (and other, entirely different, cosmic-ray/cloud connections).
Tea Partier says in #22 “True, but there is downward trend in the period 1966 to 1996″ and a strong upward trend since, peaking in 2010 which is one of the warmest years in the temperature record, while the first decennium of this century is by far the warmest in the record. Please explain these cherries.
Comment by Dikran Marsupial — 25 Aug 2011 @ 7:17 AM
Another point that receives little attention is spatial variation in the secondary cosmic ray flux that reaches the lower atmosphere, as well as its composition. Upon reaching the upper atmosphere the primary cosmic rays (mostly protons) cause nuclear disintegrations, which in turn give rise to a shower of secondary cosmic rays, including the neutron flux that is typically used as a measure of CR strength and solar modulation.
1) The neutron monitor data shown here are from Oulu, Northern Finland. At high latitudes solar modulation of cosmic rays is much stronger, at the equator you would be looking at <5% of variation. The reason for this is the shielding effect of the earth, which is strong at the equator, and practically absent at the poles. So the 10-20% you use in the calculations surely is an overestimate for the globe, in particular when weighed by the relatively small surface area of the high latitudes.
2) The muon component of the secondary cosmic rays is often used to explain the ionizing effect of CRs. In the CLOUD study in Nature they use a pion beam (pions are also charged particles; pions have a short lifetime and typically decay to muons before reaching the lower atmosphere). However, the muons originate from high-energy primary cosmic rays, which are thought to be hardly modulated by solar activity, even at high latitudes. There is much less muon data available than neutron monitor data, which is probably the reason why the neutron data is always shown. But there is no reason to believe the muons are modulated in the exact same way that neutrons are.
Many of these effects are nicely explained in Lifton et al 2005 ("Addressing solar modulation and long-term uncertainties in scaling
secondary cosmic rays for in situ cosmogenic nuclide applications")
To summarize: high latitude neutron monitor data do not represent the entire globe, and do not represent the muon flux that is held responsible for aerosol nucleation.
Perhaps a 5th point to add to your list things that need be worked out before we can assess the influence of GCR on global climate!
GCR count is most likely too low (unless there is some kind of ‘chain reaction’ within cloud formation process) to make any significant difference.
But, if there is a GCR-climate link than the feedback may be a positive one (clouds also prevent heat loss at night, particularly at higher latitudes and the Arctic’s winter months).
Some relevant facts:
- The Earth’s magnetic field (gmf) is far stronger modulator of the GCRs then the heliospheric mf.
- The Arctic’s gmf intensity moves in the opposite direction to the solar mf: http://www.vukcevic.talktalk.net/LFC9.htm (vukcevic discovery)
- Since 1800 the global gmf lost about 10% of its strength, so the GCR count (and clouds) should have gone up strongly, and according to the Svensmark’s albedo hypothesis causing global cooling; but we had global warming since 1800, in line with the idea of a positive feedback induced by gamogenetically GCR modulation.
- There is a good correlation between temperature movements and the gmf: http://www.vukcevic.talktalk.net/NFC1.htm http://www.vukcevic.talktalk.net/LL.htm http://www.vukcevic.talktalk.net/HmL.gif
The CERN press briefing is quite good on what they say it all means. Particularly clear is their final conclusion: “However, it is premature to conclude that cosmic rays have a significant influence on climate until the additional nucleating vapours have been identified, their ion enhancement measured, and the ultimate effects on clouds have been confirmed.”
The 2 deepest “troughs” in the neutron count of 1982 and 1991 unfortunately were close to major volcanic eruptions (El Chichon and Pinatubo), so the results are muddied. Otherwise it is true that we should see warming pulses during the “troughs” in the neutron count on or after (approximately) 1958, 1969, 1981, 1990, and 2000. Is that true? I think if you extracted the ENSO “noise” from the signal it might be.
[Response: You are clutching at straws. There would only be a minimal delay between GCR changes and cloud formation if this is a big effect. If you posit that the very small change from 1966 to 1996 is enough to cause a 1% (?) change in global clouds, then the solar cycle effects would be an order of magnitude larger. There is no evidence of this at all. Other factors also strongly mitigate against an effect this large - the ionisation from radon is dominant over much of the land surface - you would see that in the cloud data (you don't). The Laschamp excursion led to a dramatic increase in GCR around 40,000 years ago (seen clearly in the 10Be ice core data), but did not noticeably impact climate at all. This doesn't mean that there is no modulation of climate, just that it isn't the enormously dominant player people like Calder or Svensmark imagine. - gavin]
CM #23. Yes, the case of the FD observations is definitely not closed. The difference between the Kristjánsson and Svensmark papers is likely the difference in the number of FDs used in their primary results (both papers agree that using the strongest cases strengthens observed trends and using more cases buries these trends); however, Kristjánsson chooses to highlight the results from 22 events, where Svensmark chooses to highlight the results from 5. Obviously the FD question would be easier to answer if we had more observed “strong” FD events.
I was an opponent at Torston Bondo’s (Svensmark’s student) PhD defense. I wanted to know what I was getting myself into, so I re-analyzed much of the data in the Svensmark paper and tweaked some of their assumptions including some of the issues raised in the RC post (e.g. randomly removed 1 or 2 of the “big 5″ events, changed their criteria for their minimum daily AERONET measurements, not used any temporal smoothing) and the results do not change greatly. I definitely think the jury is still out, but I also think the Svensmark paper caries weight.
This all being said, I still don’t have a clue as to why these cloud changes occur. The Pierce and Adams and Snow-Kropla et al. papers that Gavin mentioned in the article are modeling work that I or my group have done. They show that the changes in nucleation from cosmic rays (consistent with these CLOUD results) lead to insignificant changes in CCN (too small to greatly affect clouds). Luckily the CLOUD experiment people are planning on testing the nucleation-CCN connection, so we don’t need to rely on only modeling for these estimates, but it will be another year or so before we see these results, I think. If the CLOUD results on nucleation-CCN agree with my group’s modeling work, some entirely different processes must be going on if cosmic rays actually are affecting clouds (again see http://www.sciencemag.org/content/298/5599/1732.abstract).
#25 “…peaking in 2010 which is one of the warmest years in the temperature record,…”
…straddled by what are likely to be (once 2011 is in) by 2 cold years (by recent standards). My point was that ocean heat gain is not there since 2003 and that coincides with an elevated neutron count since roughly the same time.
#34 “…The difference between the Kristjánsson and Svensmark papers is likely the difference in the number of FDs…”
Neither paper attempts to filter FD events for weather related masking of the effect (If my memory serves correct), but High/Low pressure systems in waxing/waning modes must have a large potential to obscure the GCR signal if it exists. That fact that a signal appears in the strongest FD events, irrespective of weather, is an indication the effect is significant.
With respect to figure 2, you say there has been no discernable trend. But that graph doesn’t plot the trend does it. (Hint) The trend depends on the not just the peak amplitude, but the troughs and the width of these peaks and troughs. The troughs actually show a downward trend to 1990 and recently there has been an upward trend. Of course we can’t really determine this by eyeballing the graph can we.
Why don’t post the trend and not raw data?
Comment by Bob from the UK — 25 Aug 2011 @ 11:33 AM
> more aerosols
DMS: The Climate Gas You’ve Never Heard Of
Made by tiny plants in the ocean, dimethylsulfide helps make clouds in the sky
“… the question becomes, can algae produce enough DMS to increase cloud cover and keep the planet’s temperature from rising ….”
(good article, names many of those who are publishing in this area and provides links to their home pages and research articles)
What happened to dust particles being the condensation nuclei? Aren’t there plenty of dust particles?
Comment by Edward Greisch — 25 Aug 2011 @ 12:56 PM
> climate/CGR link
Don’t presume what you want to find out — whether there is a link.
At most there are a variety of correlations and a variety of hypotheses, and they don’t consistently add up (yet), near as I can tell. That’s why I asked above about possible intervening variables or other factors that might also correlate with the observations and whether any have been investigated sufficiently to rule them out.
#36, CM: Cheers!
#43, Edward: Yes, dust and other primary particles (e.g. soot, sea salt) can act as cloud condensation nuclei (CCN) too. Aerosol nucleation is not the only way CCN are formed. Both nucleation and primary emissions are important, but it varies from region to region. As you can imagine, dust may be the dominant CCN source in dust storms blown off of the Sahara.
Thus, the impact of cosmic rays on CCN/clouds is also limited by primary emissions contributing to CCN. Even in the case where there is no nucleation (and thus no impact of cosmic rays on aerosol nucleation) there will still be CCN (albeit a reduced amount) for cloud droplets to form on.
Because the mechanisms are uncertain, the apparent relationship between solar variability and cloud cover has been interpreted to result not only from changing cosmic ray fluxes modulated by solar activity in the heliosphere (Usoskin et al., 2004) and solar-induced changes in ozone (Udelhofen and Cess, 2001), but also from sea surface temperatures altered directly by changing total solar irradiance (Kristjánsson et al., 2002) and by internal variability due to the El Niño-Southern Oscillation (Kernthaler et al., 1999). In reality, different direct and indirect physical processes (such as those described in Section 9.2) may operate simultaneously.
There are repeated complaints about Recaptcha which I find unjustified. Cycling through the process, I can read at least 80% without difficulty, though this is an update on rather worse previous values, following the reformatting of the confusion parameter from blurred doubling to superposition of a sine wave.
“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). ”
Isn’t it true that a ‘trend’ wouldn’t be required but simply an offset over recent decades? The offset creates the imbalance which results in the energy build up…
It is also important to understand that an offset is most difficult to identify.
#34 “…The difference between the Kristjánsson and Svensmark papers is likely the difference in the number of FDs used in their primary results…”
If memory serves correct neither paper filters the data based on weather events coincident with FD events. The presence of waxing/waning major low pressure systems would obscure the GCR effect I would think. The fact that major FD events have a signal of any kind showing through cloud data indicates the GCR effect is likely significant.
Filtering weaker FD events for only those coincident with high pressure weather systems over the east Pacific etc. might improve the chances of seeing a GCR signal from weaker FD events.
Please add FD “Forbush decrease, in astronomy, a decrease in observed cosmic ray intensity” to the acronym-index/
45 Jeff Pierce: Thanks. By the feel of my lungs, I would say that there are plenty of somethings in the air around here.
47 SecularAnimist: Content-free “bombshells” are the best kind when leading content-free minds. That is the beauty of that kind of “leadership.” No thinking is required. The followers never think to ask for content. Yet they keep on reading the same stuff.
I’ve always known that Scottish scientists punch way over their weight but for 63 foreign scientists to essentially come up with similar results to Charlie Wilson almost exactly 100 years after he invented the first cloud chamber (he observed real clouds and didn’t need to invent a crazy mnemonic) says much for the quality of science conducted in Scotland 100 years ago. I bet that Charlie operated on a shoe string budget unlike what scientists get today.
Of course the big problem with the cosmic ray theory of global warming is that there is no long time trend for cosmic rays but that wont stop the deniers from spinning this report like crazy.
“Oddly, not one of those comments that I have seen bothers to explain exactly what the supposed “bombshell” is.”
Here, let me explain it for you.
We already know that the AGW cult hasn’t even produced one decent predictive model that A) when applied to historical data, actually predicts known future results, and B) makes even a half decent effort at properly accounting for *clouds*.
[Response: So supporting a theory that works and produces validated predictions makes you part of a cult? Curious. - gavin]
And now we’ve just added that all the models you adore have been completely wrong – by at least an order of magnitude – in accessing the impact of cosmic rays as well.
[Response: You've just made this up. The modelling of the full aerosol growth and decay cycle is relatively new - with people like Jeff Pierce (see above), Peter Adams or Susanne Bauer leading the charge. It's fascinating (and uncertain) stuff, but it is a small part of the overall picture. The overall effects of CR changes estimated via these models are indeed small, but that is pretty much in line with the very limited results shown in this paper. - gavin]
This post introduces several strawmen. The big one is that the anti-AGW crowd is claiming the cosmic rays are the “dominant driver” of climate change. We don’t have to prove that. We just have to prove you don’t have a clue.
[Response: Have you even read Svensmark's book? Thought not. - gavin]
[edit - political tedium removed]
But when you guys assume, as always, that the burden of proof is on the -other- guy to continually prove a negative, and if we don’t, we have to give you trillions of dollars… why, I bet you feel like you win every single debate, don’t you?
[Response: Oh please. No one is giving scientists 'trillions' of dollars. And if this is your answer for why this is a 'bombshell' paper, you completely fail to make your case. You appear to be arguing that anything that you perceive as anti-AGW (incorrectly, and in stark contradiction to what the authors themselves claim) must be a bombshell because, well,.... 'trillions of dollars'. That isn't an argument, it's a knee-jerk. Try and be a little more reflexive, and even sceptical. - gavin]
I you look at the Oulu neutron counts during solar maximas from 1970 to 1990, there’s significant drop in the neutron count during hight solar activity. This could partly account for the warming from 1970′s to 1990′s.
An interesting comment found at the UK Daily Mail (not a place I normally go for climate science):
“Commenting on the Nature paper, Prof Arnold Wolfendale, Professor of Physics at Durham University has pointed out several other holes in the cosmic ray idea, notably the fact that we would expect to see cigar-shaped clouds in the high atmosphere following cosmic ray tracks – we don’t.”
All the focus has been on the actual CLOUD experiment, but surely there are other signatures like clound shape.
Congratulation for another VERY good post (and well-timed)!
Just one quick question – isn’t all this cosmic-ray link (in the absence of any trend in recent times) mostly an argument for a higher actual sensitivity (but probably ‘fully kicking in’ more on the medium-term, after 2-3 solar cycles)?
I’m familiar with a fair handful of the authors of this paper (a few on a personal level) and have a lot of respect for them as scientists, so the lack of spin is nothing more than I would expect. There is a lot of very good science out there, it’s just a shame that it is the spin-heavy stuff that more routinely gets the public attention. In terms of presentation, I think what the authors deserve a certain amount of credit for is the lack of gems available for the denialist quote-miners. It’s a fair assumption that the usual suspects are currently trying to mangle this article for all it’s worth.
And for the record, one of the most noteworthy things for me about the experiment was how clean they managed to get the chamber. This, if nothing else, is what made this experiment truly unique compared to those conducted at other facilities. Although the instrumentation is pretty cool, I admit.
I agree that this is not the slam dunk proof that the denialists claim it is. But it does lend support to Svensmark’s theories. At the very least, it doesn’t disprove them. In the text you provide additional steps that would be needed to show the correlation, so, you clearly are not dismissing the possibility that cosmic rays influence on cloud formation could be a much more significant contribution to global temperature change that previously thought.
I think what this paper most significantly shows is that the science is definitely not settled.
[Response: This idea far predates Svensmark - going back to Ney in the 1950s or Dickinson in the 1970s. What people have objected to in Svensmark's work is not the idea that there are potential connections between GCR fluxes and climate, but rather the ridiculous overselling of their results, the inappropriate manipulation of data, and the lack of predictability of any of their proposed correlations when new data arrives. There are many issues in climate that are worth more study and this is certainly one of them, regardless of the previous overwrought hyperbole. - gavin]
Qwinn, whose litany of belligerent right-wing bumper sticker slogans inexplicably received a thoughtful, respectful response from Gavin rather than being consigned to the darkest depths of the Bore Hole where such Ditto-Head drivel belongs, wrote:
“We just have to prove you don’t have a clue.”
Which you have utterly failed to do by regurgitating nonsense and falsehoods.
Gavin, Is this trend up or down? Haven’t the amount of aersols gone down in the past 60 years due to clean air act and similar measures?
If so, *might* we be seeing a net positive contribution to ave. Global temperatures because less clouds are forming at this boundary layer due to this aerosol nucleation phenomena?
Also, has anyone actually done a study on nighttime global trends vs. daytime global trends?
thanks in advance!
[Response: Over the last 100 years, definitely up globally. But regional emissions have varied enormously. For instance, US black carbon probably peaked in the 1930s (from Greenland ice cores), sulphate aerosols in the US, Japan and EU peaked around 1990 (down since), in China/India they have not yet reached the peak, biomass burning in the tropics is peaking now. - gavin]
Wow, the right wing picked up the spin on this paper in a hurry!
The hypocrisy is really unbelievable. There are thousands of papers on this subject that are completely overlooked and dismissed as some sort of scientific cabal to fool the world into a marxist new world order, yet they latch onto any scientific paper that even hints at supporting their misguided and uninformed ideas.
This cherry picking of science to support politically motivated propaganda is depressing.
The reality is there is now a real alternative to agw theory and its called gcr. If the Danes estimates turn out to have credibility which appears to be the case the models for agw have to be cut in half! At the very least.
[Response: This is hilarious. You read something that you percieve to be against mainstream thinking (wrongly) and then without any work on attribution at all, you arbitrarily reduce the attribution to anthropogenic effects by 50% (at least!). The irony here is impressive. - gavin]
I think what this paper most significantly shows is that the science is definitely not settled.
I’ve seen this particular moved goalpost arise a lot of late. It’s almost as if it’s the new denial stance. It’s not that AGW isn’t or couldn’t be happening, it’s all of that stuff that we gee whiz just don’t know yet, so maybe we’re being hasty.
The missing contaminant is nitrogen dioxide, which catalyzes the oxidation of sulfur dioxide to sulfuric acid in the presence of moisture. The reaction is rapid and yields are near 100%. The nitrogen dioxide is not consumed. The particle growth rates are limited only by the availability of moisture.
Comment by Snorbert Zangox — 26 Aug 2011 @ 3:26 PM
Scott wrote: “… they latch onto any scientific paper that even hints at supporting their misguided and uninformed ideas.”
Actually the deniers will latch onto any scientific paper that doesn’t remotely support their misguided and uninformed ideas, and pretend that it does.
I don’t agree with your interpretation. Warming can have multiple sources, including CR and CO2. My point was that the post claimed that we would need to identify a trend in the data. — This is incorrect by my understanding.
We need to identify an offset from historic values to see a change in cloud forcing (it would be considered a forcing in this case right?). I think the post should be tweaked to represent this truth.
[Response: Jeff, the point is that there is no evidence of a change, offset, trends, whatever you wish to have. Of course, it is always possible (in principle) that the current CR flux is significantly different than in the past. But even if that were true (and there is no evidence, of course), then you'd still have to contend with the orders-of-magnitude-too-small effects! --eric]
“[Response: Jeff, the point is that there is no evidence of a change, offset, trends, whatever you wish to have. Of course, it is always possible (in principle) that the current CR flux is significantly different than in the past. But even if that were true (and there is no evidence, of course), then you'd still have to contend with the orders-of-magnitude-too-small effects! --eric]”
Thank you for responding. Please understand that I haven’t claimed that this is a ‘big hole’ in any sort of model or AGW theory. There is no ‘gotcha’ in my thoughts here. I saw a comment by Gavin that we should look for trend in the data and this is flatly not correct. It is an easy fix at my blog, it should be equally so here. It should say offset in CR as temperature is an integration of forcing minus outbound flux. It is a word change and a shoulder shrug. That’s what I would do.
You say that there is no evidence that CR is ‘significantly’ different (I’m starting to hate that word), but then you claim that there are orders of magnitude too small effects. I don’t know. Flat out, don’t have a clue. Someday I might. Without reservation, if you would tell us why you are certain that the effects are too small to make a difference, all I can do is listen. Last time you commented at tAV, I was hoping you would clarify those comments as well.
Again, thanks for letting these difficult comments through and I am interested in any of your group’s replies. If we are going to waste our time blogging, why not learn.
[Response: Jeff: An epoch to epoch change, when fit linearly, will give a trend. There's nothing wrong with calling it a trend (even if that does invoke images of a monotonic increase). I get your point, but it a semantic one. You're essentially saying "maybe if we had data from 50 years ago, we would find that there *is* a difference, and hence a trend, and maybe (if we take into account the response time of the system, plus unforced variability), we'd be able to show that there is actually a plausible correlative relationship between climate and CR. But you'd still be left with no evidence that the effects are big. I didn't say I was certain they are small, just that there is no evidence otherwise. And of course there are lots of other things that we know do have big effects on cloud nucleation (like, as Gavin said, plain old pollution (SO2 emissions)) and on radiative forcing (like, for example, CO2).
It seems to me you are trying to say that the 'jury is still out'. That's fine. But to take that analogy further, there isn't even really much of a defendant for the jury to decide on! Meanwhile, the CO2 case has already been prosecuted and sentenced.--eric]
My point was that when nitrogen dioxide, which is always present in the outdoor atmosphere is added to the mixture in the experimental chamber, the rate of conversion of sulfur dioxide to sulfuric acid will accelerate dramatically. The order of magnitude deficiency that Gavin referred to earlier will disappear.
I do not know why your rendition of the historical frequency of cosmic rays differs so radically from the data of others.
[Response: The CR data are direct plots of the pressure corrected data. If other people have something different, they are not looking at the primary source. (Oh, NOx is not the issue since they injected H2SO4 directly, not SO2). - gavin ]
Comment by Snorbert Zangox — 26 Aug 2011 @ 10:21 PM
#73 “it is always possible (in principle) that the current CR flux is significantly different than in the past.” On the other hand it is CERTAIN that the rate of increase of CO2 in atmosphere in last 30 odd years, and the causative increase in industrialisation, is unprecedented. Lo and behold, so is global warming! What are the odds that whatever CR might or might not be doing they would be mimicking the effects of that CO2 rise at precisely this time in our history?
Thanks again Eric. This is the part which I have a problem with:
“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 ”
To be accurate, it should say:
“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 difference in cosmic rays over recent decades – which is tricky, because the data is too short”
Now I have introduced the ‘too short’ point here for the first time, but Figure 2 data is far too short to claim any difference or lack thereof inside the noise. But again, you don’t need to find a trend as explicitly stated above, you need to find an offset which would integrate into a temperature blade over time. It is not semantic as I understand it. Isn’t it accurate that physics dictates that the integral of a power (Watts) imbalance leads to temperature rise, so the statement as written misleads the casual reader into expecting the hockeystick blade from a short bit of not-yet-integrated, high variance forcing data?
The real answer is that from Figure 2 as shown, we don’t know anything new and shouldn’t expect to know anything new about a change in cosmic ray’s which would affect climate in recent decades.
From the certainty of the articles conclusion, I wondered if anyone here knew of a good quality long term data source for cosmic rays that should replace figure 2. If it exists, it would explain the conclusion quoted here. I don’t know of any because my background is limited and a better plot may be common knowledge for you guys. If it isn’t available,then it seems the quote here should be corrected to demonstrate the proper uncertainty to the public.
PS, Bringing the CO2 argument seems moot at this point. It is quite possible that this effect doesn’t have to be a ‘warming’ one. It could explain why observed temperature trends are running somewhat below many of the models as well and you might have a valid, ‘worse than we thought’ on your hands.
Again, if I’m wrong about any of the above, I’m listening.
[Response: Jeff. Gavin's point about 'no trend' however is partly in response to those that have claimed that the warming of just the last 30 years is GCR. But sure, 'too short' is fine, and perhaps more relevant. But the take home here is a correction to your P.S.: "...observed temperature trends are running somewhat below some models, well above others, and since we have absolutely no clue which direct the GCR effect ought to go, even if it is important (for which there is no evidence), it is not clear whether it would help explain anything whatsoever." That would be a little more honest than Watts ridiculous "a non-visible light irradiance effect on Earth’s cloud seeds has been confirmed", dontcha think?--eric]
I wonder if a GRACE is possible for mapping water tables in the boreal forest, tundra, and maybe soon rock, North of 45^0-50^0 latitude? Also a clay satellite might be useful. Peat has a different density than does water, than does ice, than does the living Acrotelm layer. Extra points for differentiating non-fuscum vegetation. Clay might be useful to spread over microsite depressions where water may be scarce or slope high. IDK about mapping clay deposits but the terrain is isolated and sometimes marshy; easier with satellite. The clay satellite need only be temporary; IDK yet if clay’s capillary physics acts as a water reservoir for acrotelm like peat does.
Water table to within a few cms is worth $$. Few tens of cms is okay. Sphagnum is best at -15cm water table except jr sphagnum at maybe -5cm. This would be best a permanent satellite.
“…which is tricky, because the data is too short” Jeff Id — 27 Aug 2011 @ 8:16 AM
No. As Svensmark’s analysis showed, clouds respond within days to the transient changes from Forbush events. Further, the diurnal variation in temperature and its change between cloudy and clear skies show a rapid response to this forcing. Download 30 years of monthly data, CR from Oulu, and UAH from woodfortrees, and plot them using a spreadsheet. There is an obvious cyclic variation in CR data corresponding to the solar cycle, but little obvious correlation to temperatures. Sort the monthly data pairs by CR intensity, and plot that data. This puts the temperatures during low CR counts, ~’82, ’90, ’00-’02 on the left side of the graph, and temperatures during high CR counts, ~’87, ~’97, ~’09, to the right. This will tend to remove the trend in UAH temperature due to global warming, since early and late years get mixed together. There remains a weak POSITIVE correlation with Oulu CR and UAH Temperature, 0.274. I may be able to upload graphs to an image site later.
The CERN press release is rather clear. There are 2 different results;
1 High clouds do form in greater numbers thanks to cosmic rays.
2 Low clouds are formed far more more by vapours ammonia than gcr.
Jasper Kirkby. “We’ve found that cosmic rays significantly enhance the formation of aerosol particles in the mid troposphere and above. These aerosols can eventually grow into the seeds for clouds. However, we’ve found that the vapours previously thought to account for all aerosol formation in the lower atmosphere can only account for a small fraction of the observations – even with the enhancement of cosmic rays.”
The CLOUD results show that a few kilometres up in the atmosphere sulphuric acid and water vapour can rapidly form clusters, and that cosmic rays enhance the formation rate by up to ten-fold or more. However, in the lowest layer of the atmosphere, within about a kilometre of Earth’s surface, the CLOUD results show that additional vapours such as ammonia are required. http://press.web.cern.ch/press/PressReleases/Releases2011/PR15.11E.html
Conclusion 1. cr does influence high clouds ‘enhance the formation rate by up to ten-fold or more’ and 2. don’t make much diff. for low clouds and where trace vapours do far more than thought.
[Response: Not quite. The connection to high clouds is tenuous since they didn't do experiments that were appropriate to that altitude (press, concentrations etc.). Rather they took the experiments for the boundary layer and just made it colder in order to increase nucleation. Of course, if they had really concluded that GCR were a bigger issue for higher clouds, that would mean that they were likely to be a global warming effect. - gavin]
Brian, thanks for the reply but Fig 2 data is quite obviously too short to determine any differential from prior time.
Regarding air temps, they are controlled by ocean surface temp. Expecting the oceans temp to oscillate on decade timescales, misunderstands the total energy capacity of the oceans. I don’t think anyone would expect a cosmic ray forcing to drive the ocean temps up and down every solar cycle, but it is possible to add/subtract a little every year with a net positive/negative forcing that would add up over multiple decades.
“A total of 125 large fluence solar proton events identified from the nitrate
deposition in ice core from Greenland for the period 1561-1950 are examined in an exploratory study of the geophysical information that will be available from such data in the future. These data have been augmented with ionospheric and satellite data for the period 1950-1994….”
#33 “…The Laschamp excursion led to a dramatic increase in GCR around 40,000 years ago (seen clearly in the 10Be ice core data), but did not noticeably impact climate at all…”
I’m not sure the Laschamp excursion is a relevent argument for why GCR can’t modulate climate. At the time the earth was in the depths of an ice age with lots of dust flying around, a depressed biosphere due to low CO2, and a suppressed hydrological cycle. We see from this latest CERN paper that ammonia may be a critical component for the leverage of GCR on cloud formation. What was the ammonia content of the troposphere 40K years ago?
Gavin’s reasons for conclusions about no trend are the single problem I discussed with this post. You guys are the pro’s so we look to you for answers to questions when our less than full time studies can’t answer them. In fact, RC was the blog I asked questions of well prior to tAV on other issues. I did not know, until your reply, that climate science didn’t have an answer to the direction of cosmic ray’s. I was educated enough to wonder about it because of course I do know of the solar proxy data and recognized the difference.
I may write a post on this exchange if I find time, hopefully your group will consider my suggestions for changes above.
The research is working to identify signals in the various proxies for paleo work, the CERN work is looking into what other variable factors may also be involved, and much else. Whatever’s there is a small effect from a lot of factors. Flip the planet’s magnetic field
“… as this paper shows – we’re not even sure what all of the gases are,” said lead author Jasper Kirkby from CERN in Geneva, Switzerland. “We’ve found that [in addition to sulphuric acid and ammonia] there has to be another vapour (or vapours) involved, which has a controlling influence.”
The problem is whatever’s there isn’t big strong obvious and simple.
It’s easy to speculate, but speculation proves nothing.
Is the missing multiplier/mystery vapour CO2? nitrogen from agriculture? DMS? Sulfates? hydrocarbons? One of the many thousands of other artificial chemicals maybe? Is a geomagnetic excursion or field flip, e.g. Dergachev et al., needed to make the effect big enough to be detectable in the proxies? http://cat.inist.fr/?aModele=afficheN&cpsidt=16174190
Whatever it is it’s small compared to the big control knob we know about.
Gavin, you wrote, “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).” There is a trend, and it’s up. The trend of the pressure-corrected Oulu neutron count since April 1964 is y = 0.3935x + 6026.6 (resolution of one month to reduce the size of the spreadsheet and apply some smoothing. (The data are provided by Sodankyla Geophysical Observatory and are available in many resolutions at http://cosmicrays.oulu.fi/). I generally do not apply a linear regression to so few cycles but thought this might be of interest. (I do apply linear regressions to my atmospheric data, but these observations were begun in 1990 and constitute nearly 22 annual cycles.)
[Response: Uh.. What are the units of x and y, and what is the confidence interval on that trend. I'll bet is it much greater than the slope of the best fit line. if so, then, no trend...--eric]
The On-Line Database of Cosmic Ray Intensities at http://cosmicrays.oulu.fi/ICRC_NMdb.pdf
looks like it ought to have a lot to say about the issue. Is that what RC people have already looked at? If that data is flat, issue answered.
Comment by Edward Greisch — 27 Aug 2011 @ 11:59 PM
How about other sites? This paper mentions many (no specific numbers given for most of the other sites, but it seems to say the trend is generally down)
“… As illustrated in Figure 1, most neutron monitors
return to approximately the same count rate from one solar
minimum (cosmic ray maximum) to the next. However, the
South Pole monitor displays a remarkably different behavior
consistent with a steady long-term downtrend. Even the
monitor at Mt. Washington (not shown), which is perhaps
most comparable to South Pole in terms of cutoff and
altitude, displays no such marked downtrend [Lockwood
et al., 2001].”
“… In summary, we have not been able to identify any
instrumental or environmental effect that could cause the
long-term decrease in the South Pole neutron rate. Unless
some such cause emerges in the future, it would appear the
origin of the decrease must be a change in the Sun or solar
wind, with an attendant change in the strength of solar
modulation of cosmic rays [Ahluwalia and Lopate, 2001;
Caballero-Lopez et al., 2004; McCracken et al., 2004a,
2004b], or possibly a change in the local interstellar density
of Galactic cosmic rays [Stozhkov et al., 2000].”
Lots of discussion of statistics in this one, for those who like that sort of thing.
Brief excerpt follows
“… while many people might claim to recognize a trend when they see one, a more precise, but still usefully general, definition is difficult to pronounce (e.g. Preece, 1987). We are reminded of the limerick by Cairncross (1969): “A trend is a trend is a trend …”. To which we would unpoetically add the hope that a graph of the data would have a visually-compelling slope.
Of course, needed specificity for what is meant by “trend” can be obtained through (2) measuring and testing. These typically involve either deterministic or stochastic analysis, with limitations imposed by data quantity and quality, and the possible presence of superimposed signals. Here, the notion of significance is important, as is the timescale over which the trend is supposed to apply. And there are practical considerations ….
… While fits to data across all 13 solar cycles seem to show a linear trend of increasing geomagnetic disturbance, fits to shorter durations, such as for 6, 4, 3, or 2 cycles, do not consistently show persistence. Indeed, Figs. 1 and 2 show that the time-dependence of past geomagnetic activity has been complicated.
Clearly, our observation of a long-term linear trend of increased geomagnetic disturbance is due, in part, to the time span we have considered, the span of the available geomagnetic K time series, 13 solar cycles.
This is a simple, but important, observation that has been made by others (e.g. Richardson et al., 2002, Fig. 1; Mursula et al., 2004, Fig. 3).
If we had chosen to analyze the time span of (say) the past 6 solar cycles, we would, instead, be discussing a decreasing trend in geomagnetic disturbance!
(extra ‘paragraph’ breaks added for online readability — hr)
This is the quote I see ALL over the web on denialist sites:
“When Dr Kirkby first described the theory in 1998, he suggested cosmic rays “will probably be able to account for somewhere between a half and the whole of the increase in the Earth’s temperature that we have seen in the last century.”
This seems exceptionally sweeping and wild, and I have a funny feeling Kirby never said it, as the denialist vermin have an unpleasant habit of simply inventing stuff.
Anyone know if this widely circulated quote is indeed accurate?
[Response: It comes from a 1998 physics world article - and I agree with you, it seems exceptionally sweeping and wild and is not the kind of thing you'd expect scientists to say prior to having any actual evidence. - gavin]
ConCERN Trolling on Cosmic Rays, Clouds, and Climate Change
ANd here i read, quote:
RealClimate has a good rundown of what Kirkby et al.’s results do and do not mean. The short version is that Kirkby et al. do find increased aerosol nucleation under increased ionization (i.e. “more cosmic rays”), particularly in the mid-troposphere, but the effect is smaller at warmer, lower levels where the cosmic ray-climate myth proponents claim it has its greatest climatic effect. Lead author Jasper Kirkby has tried to set the record straight, stating (all following emphases mine):
What has CLOUD discovered and why is it important for our understanding of climate? There are several
important discoveries from CLOUD. Firstly, we have shown that the most likely nucleating vapours, sulphuric
acid and ammonia, cannot account for nucleation that is observed in the lower atmosphere. The nucleation
observed in the chamber occurs at only one‐tenth to one‐thousandth of the rate observed in the lower
atmosphere. Based on the first results from CLOUD, it is clear that the treatment of aerosol formation in
climate models will need to be substantially revised, since all models assume that nucleation is caused by
these vapours and water alone.
[Response: "Climate models need to be substantially revised" is a cliche that seems to be appended to any experimental result that is connected to climate, particularly when no climate models or their results have been discussed in the paper at all. The context that is missing is that aerosol nucleation processes don't actually figure in 99% of climate model results, and so it is unlikely that any of those need to be revised in the slightest. People need to remember that climate modelling is a hierarchy going from the relatively simple to the extremely complex, but not every element in the very complex models impacts the top-level results in the simpler formulations. Take aerosol nucleation - this figures only in models that attempt to capture the whole aerosol growth and decay process (such as the model in Pierce and Adams (2008), or the MATRIX module. It does not figure in the AR4 models, and even though the CMIP5 models have substantially more aerosol/chemistry than CMIP3, the nucleation process isn't included in them either. Instead, these models base their aerosol physics on empirical large scale effects - not explicit microphysics. Obviously one can learn a lot from doing more 'a priori' calculations (which is why MATRIX/Pierce and Adams etc. are happening), but it only indirectly affects the bulk aerosol modules that are used in most the current GCMs. And even then, I'm not sure enough about the details of the aerosol microphysics used in the a priori calculations to know whether they need to be 'substantially revised' as a function of this paper. Perhaps Jeff Pierce could comment? - gavin]
Comment by Pete Dunkelberg — 28 Aug 2011 @ 10:40 PM
Gavin: “1.… that increased nucleation gives rise to increased numbers of (much larger) cloud condensation nuclei (CCN)”
Doesn’t common sense tell you this? You don’t go from single atoms or small molecules to CCNs in a single step. These things must grow gradually from very small to very large. And the more of the small components that are available to grow into CCNs, the more CCNs there will be. Of course the Forbush decreases that Svensmark et al found confirm that this is what happens.
I’m not sure how Svensmark’s name being on the paper is relevant, especially since Svensmark’s own SKY experiments anticipated these results.
It seems to me that you’re arguing that a stepwise change in GCR before 1950 could have caused (part of the observed) warming after 1975. That seems entirely implausible though:
a) I would not expect the temperature to suddenly increase (after a period of little change) long after the forcing has stopped changing (if that forcing is dominant).
b) Timescales for the GCR-aerosols-climate link are pretty short, so even more reason to expect a quick response in “climate” when GCR conditions are changing.
Btw, I agree with James Allan that the authorlist of this article has many very good researchers on it who have not staked out a contrarian position on climate. Note that Svensmark is absent, which could perhaps explain the missing spin.
Bart Verheggen: “It seems to me that you’re arguing that a stepwise change in GCR before 1950 could have caused (part of the observed) warming after 1975. That seems entirely implausible though:”
The strength of solar cycles was climbing strongly up through the late 1950s. But there is no reason to think that climate had reached equilibrium at the same time that we reached the peak solar cycle. After solar cycle 19, 20 to 23 were still strong cycles, so temperature could still have been climbing to equilibrium with regards to solar cycles. On a shorter time scale, the temperature doesn’t have to follow the cycles exactly. The solar GCR effect doesn’t act in isolation. Any GCR signal would still be modulated by ENSO, volcanoes, and a CO2 climate sensitivity that could be around 1C.
[Response: So now we are making progress. You accept that a) all factors need to be weighed in any attribution study, b) that there is thermal inertia and c) that there is internal variability unconnected to any forcing. So far, so good. But how should such an attribution proceed? Perhaps we could look at the impacts of all the individual processes and their likely time-evolution? Then perhaps we could try and see what would happen if we did them all together? And perhaps we would be careful to allow for some multiplicative factor to account for some uncertainty in the magnitude of the effects? And have multiple estimates of the role of internal variability in order to account for that? Still with me?
#95, Pete Dunkelberg: The “climate models need to be substantially revised” comment. I don’t think this comment has anything to do with their cosmic ray results (and I’ve found it interesting that the media has used it as a statement about the cosmic rays), and I’ll explain why in a moment…
But first regarding the IPCC climate models, I think Gavin explains it well. Right now the IPCC climate models don’t take into account any aspect of aerosol number or size (just the total mass). Thus, they do not take nucleation into account. If changes in nucleation with time end up being important for climate change, we will need to incorporate these physics into the IPCC models. The comment really is directed at people like me (and about 10-20 other groups around the world) who use detailed global (or regional) aerosol microphysics models.
However, the comment is really stating that the CLOUD experiments could not reproduce atmospheric nucleation rates from sulfuric acid + ammonia + cosmic rays + water vapor, “The nucleation observed in the chamber occurs at only one‐tenth to one‐thousandth of the rate observed in the lower atmosphere.”. Therefore, some other component (e.g. organic vapors) needs to be included in order for the CLOUD experiments match atmospheric nucleation in their chamber. These are going to be the results from the next set of CLOUD experiments (which occurred earlier this summer), and they are foreshadowing these results. They do not actually bring up cosmic rays in that paragraph at all, but they make it clear in the paper that even with cosmic rays cranked up in the chamber that they still cannot reproduce atmospheric nucleation rates.
Since detailed aerosol models (like the one I use) do not include organics (or these other missing species) in the nucleation calculations, THESE missing components are what needs to be revised in our models, not the dependence of cosmic rays. Recent modeling by my group and those out of Fangqun Yu’s group at SUNY Albany does use a nucleation scheme that has a dependence on cosmic rays that is very similar to the CLOUD results. Thus, our models don’t need to be revised based on the cosmic ray results, but they do for the additional missing components (e.g. organics).
Gavin: “Perhaps we could look at the impacts of all the individual processes and their likely time-evolution?”
Certainly. For example, while the rise of solar cycle strength level off in the late 50s, we switched to an El Nino dominated mode of ENSO around 1977 that could well have continued to drive temperature up even if GCRs were no longer increasing.
So, with the possibility of the GCR effect not having reached equilibrium and ENSO kicking in to help and CO2 kicking in to help, we could easily have seen what we see in the record. Certainly a CO2 only attribution would be an error.
Gavin: “And have multiple estimates of the role of internal variability in order to account for that?”
I’m not sure that multiple estimates increase accuracy. Multiple estimates may be better than the worst of the estimates, but I doubt they are better than the best of the estimates.
Gavin: “Oh yes”
Did you find GCRs included in the attribution considerations?
[Response: The impact on temperatures of an increase in solar activity to 1950 and then flat, would have been an increase to a little past 1950 and a roughly exponentially slowing warming since. The timescale for the exponential is related to the sensitivity of the climate (i.e. the longer the posited delay the bigger the sensitivity - see Hansen et al, 1984 and Lindzen if you want a different perspective), and so you quickly find that large solar forcings combined with everything else just don't fit. GCR are proportional to TSI and so to first order a mutliplicative factor on TSI forcing would capture the main effects on global mean temperature - that is already taken into account in D&A studies. - gavin]
Jeff Pierce: “However, the comment is really stating that the CLOUD experiments could not reproduce atmospheric nucleation rates from sulfuric acid + ammonia + cosmic rays + water vapor, “The nucleation observed in the chamber occurs at only one‐tenth to one‐thousandth of the rate observed in the lower atmosphere.”.”
And yet Svenmark’s data on Forbush decreases show a variation of liquid water in clouds of 6-9%.
Jeff Pierce: “THESE missing components are what needs to be revised in our models, not the dependence of cosmic rays.”
Given Svenmark’s Forbush results, are you sure that organics are not working in conjuntion with the smaller nucleation particles created by the GCRs to create CCNs.
Jeff Pierce: “Therefore, some other component (e.g. organic vapors) needs to be included in order for the CLOUD experiments match atmospheric nucleation in their chamber. These are going to be the results from the next set of CLOUD experiments (which occurred earlier this summer), and they are foreshadowing these results.”
Hopefully these experiments include cases of increasing GCRs alone, increasing organic vapors alone, and increasing the two of them together.
#101 Tilo Reber. Yes, I agree that the FD data cannot be taken lightly. Please see my earlier comment (#34) on them. However, that isn’t what the “climate models will need to be significantly revised” comment was referring to. There is A LOT of interesting stuff in the CLOUD nature paper, its not only cosmic rays.
Organics are generally required to grow nucleated particles to CCN sizes (and is included our models… albeit, there are many uncertainties regarding how much organics we should have), but what I was referring to here was organics in the nucleation process. This is what we are entirely lacking. Again, please see my earlier comment on FDs. There may be other mechanisms at work (e.g. the effects of ions on the freezing of cloud drops), and models may be lacking something important to explain them, but we really don’t know yet. The CLOUD results unfortunately haven’t changed that.
Yes, the CLOUD experiments are very well organized such that the individual contributions of different components can be determined. I’m hoping we’ll continue to learn new information from the additional CLOUD experiments.
“… Understanding the aerosol budget in the absence of anthropogenic influence is necessary to establish a baseline aerosol forcing and provide a framework for models …
… This special issue presents a snapshot of current research topics in this study area. It comprises twelve peer-reviewed open access articles spanning the full spectrum of atmospheric science research on this subject….”
How does this sort of field work make its way into climate models?
#103, Hank Roberts: Yes, I was referring to the detailed aerosol models that include nucleation. As far as I know, only one of these models (Ken Carslaw’s group in Leeds) has ran simulations with a nucleation scheme that includes organics.
Are you asking how does research on remote and natural sources make it into climate models?
In general there are 2 ways. (1) A research team publishes measurements of some chemical concentrations, a certain phenomena or some process. We test our models to see if we can represent what was observed. If the model does not represent this test, we try to see if we can better represent this process in the model (often it might be a good idea to work with the people who took the measurements). (2) The group who makes the measurements develops a parametrization, or representation, of the process for models. The models incorporate the process and test against observations.
A nice example of these is in the special issue that you sent that editorial from (http://www.hindawi.com/journals/amet/2010/si.1/). There have recently been a wealth of new observations regarding natural organic aerosols from the ocean, (see the paper, “Primary and Secondary Organic Marine Aerosol and Oceanic Biological Activity: Recent Results and New Perspectives for Future Studies”), and we are beginning to incorporate these into the detailed aerosol models, (see the paper “Global Modeling of the Oceanic Source of Organic Aerosols”). If we find in the detailed aerosol models that the marine organic aerosol sources may be important for climate change predictions, we work with the groups in charge of IPCC models in representing these processes in their models.
Thanks, Hank. Indeed organic aerosols are a very hot topic in aerosol research. They involve on the order of 100s of different compounds with a wide range of chemical properties. And now we know that they are important for aerosol nucleation and the growth of these new particles to larger sizes where they can act as Cloud Condensation Nuclei (CCN). It may be useful to have a post on organic aerosols sometime in the future.
Meow says: 24 Aug 2011 at 6:29 PM “Palle et al 2004 … Earthshine… albedo… ” Please. That study made for good press releases but the science was horribly flawed (e.g., along the lines of “Pinatubo? Where the hell is Pinaetubo?!”; “…sooooo, both the Moon and the Earth are Lambertian scatterers?!”. Almost wrote to the editor on that one.
James Dellingpole of the UK Telegraph (mainly right wing broadsheet although at times a good newspaper) who is renewned for his Anti AGW stance links svensmark and GCR to cloud formation and hence its the sun type arguments.
It seems to me, a non-scientist, quite obvious that non-human factors have a play in regulating atmospheric biochemistry. CERNs experiments validate the connections between our planet and the larger cosmos. This is one of the reasons why I love life so much. I also feel that using this study to justify continued ignorance of sulphur and CO2 pollutants, especially given their massive increase over the last few centuries, is very dangerous.
Basic (maybe dumb) question: GCR increase ionization towards creation of aerosols, right? Are CO2 and sulphur pollutants ionically charged or relatively inert?
Thanks for the article (that I had to read about three times to begin to understand) and informative posts.
I read the James Dellingpole UK Telegraph article, which was of course difficult to digest. However, more disturbing was reading many of the comments attached to the article. Truly astounding. The PR war is being won by the deniers, or so it appears from the public’s reaction to the Dellingpole trash.
#112–I wouldn’t get too alarmed. A lot of news sites have their resident denialist trolls, and the reputation of the Telly would lead me to expect a bunch of them there. Most likely, the greatest number of the true ‘public’ pass by with barely a yawn. Which is both good and bad–they are far less influenced (IMO) by denialist propaganda than we might think (or they DO think, judging by the triumphalist rhetoric frequently bubbling up), but on the other hand we aren’t having all that much effect either.
Although a dedicated ‘alarmist’, I subscribe to the Daily ‘Bellylaugh’ – (‘cos I get it at half price )- and they have published 3 letters from me.
In particular, 2 of them were very critical of AGW denier Christopher Booker who continually supports the anti-AGW cause and criticises UK efforts at Sustainability. However, Delingpole rarely appears in print – he seems to be Telegraph blog based, so those silly comments referred to there are just the only way nutty extremists can have a say.
The main environmental reporters, Geoffrey Lean and Louise Gray are clearly pro-AGW and the Telegraph is working behind the scenes with Shell and Environmental groups to influence the UK’s future energy policy – see Age Of Energy on their website.
So……. I suspect the Telegraph is doing what many other newspapers do – simulating ‘debate’ to increase sales.
And, regarding Delingpole, I’m sure most UK readers here remember the BBC recently ran an interview with him in “Horizon – Science under Attack” by Sir Paul Nurse,(President of the Royal Society) and made Delingpole look an utter fool in the eyes of millions of viewers.
I just hope the BBC now have the courage to present the CERN findings in an unbiased Horizon type program.
#111, Greg: Sulfuric acid vapor, which is formed by the oxidation of SO2 (a primary pollutant emitted from coal combustion and other sources) may become ionized in the atmosphere through GCRs or radioactive gases such as Radon. It is these sulfuric acid ions (along with perhaps nitric acid ions and ammonia ions) that are the ions that aid in aerosol nucleation.
Sulfuric acid vapor in general (even in its neutral, non-ionic form) has long been known to be the main ingredient in atmospheric aerosol nucleation (and these CLOUD results continue to show this… nucleation goes to zero at low sulfuric acid concentrations, but nucleation did not go to zero when ion concentrations were low). Therefore, changes in anthropogenic sulfur emissions have a very large impact on nucleation rates (larger than the change in nucleation due to cosmic ray changes between the solar max and min).
As far as I know CO2 does not greatly affect the ion concentrations of the atmosphere.
Before people get all breathless about this study, it may be instructive to recall the chamber experiments on cloud seeding using iodide salts in the 1940′s. They unambiguously showed greatly enhanced water droplet nucleation, following on some theoretical considerations of the interaction of I and H2O, and the observation that aerosols could nucleate raindrop formation. Subsequent decades of research and experiment have not shown simple or reproducible results for cloud seeding. So the chamber experiments from CERN are nice, but it’s pretty clear that there is a very long way to go before or if the CLOUD results can tell us much about the real atmosphere. If you’re not a big fan of cloud seeding, best to hold off on GCR as the 21st century alternative.
[Response: Thanks Lou for that cogent analysis. --eric]
[Response: The guy seems a little confused as to what the CERN experiment is studying - aerosols or greenhouse gases? - but then it is only the 'consensus' that says these things are different... - gavin]
In figure S.4 (Supplementary material) one can clearly see the build up of particles to the size of + 40 nm. Why don’t they comment on that? Is this some other irrelevant process going on or are they saving this finding for a later paper?
[Response: This is called a 'nucleation event' and happens far more haphazardly or randomly than simple nucleation of small particles. Jeff might know better, but I guess that this hasn't happened sufficiently often to get any idea of whether it is more or less common or affected some other way as a function of the inputs. - gavin]
Oceanic phytoplankton, atmospheric sulphur, cloud albedo and climate
Robert J. Charlson, James E. Lovelock, Meinrat O. Andreae & Stephen G. Warren
“The major source of cloud-condensation nuclei (CCN) over the oceans appears to be dimethylsulphide, which is produced by planktonic algae in sea water and oxidizes in the atmosphere to form a sulphate aerosol Because the reflectance (albedo) of clouds (and thus the Earth’s radiation budget) is sensitive to CCN density, biological regulation of the climate is possible through the effects of temperature and sunlight on phytoplankton population and dimethylsulphide production. To counteract the warming due to doubling of atmospheric CO2, an approximate doubling of CCN would be needed.”
Not that it matters what the originators believed, as long as the work’s done fairly.
But I find it odd that the CERN/CLOUD group seems to believe that organic material, if needed, could only increase but could not initiate the process, e.g.
“The critical cluster size associated with nucleation is somewhere between 0.8 and 3.0 nm. Some studies have found that growth rates of particles from 3.0 nm to around 20 nm cannot be accounted for using condensation of sulphuric acid alone. Volatile organics compounds could account for some of this additional growth. …”
“Cloud-making: Another human effect on the climate
24 August 2011 by Michael Le Page
IN HIS Gaia hypothesis, James Lovelock famously suggested that living organisms could affect clouds – and he was eventually proved right. Now it seems the effect may be even stronger than we thought. Organic vapours released by organisms such as trees, marine bacteria and livestock appear to play a far more important role in cloud formation than suspected.
“This was a big surprise,” says Jasper Kirkby at CERN near Geneva…..
Kirkby’s piece also refers to the ‘global electrical circuit’ affected by cosmic rays being involved in ionization and cloud formation.
#123: Bengt A: You are right in thinking that this growth to 40 nm (and larger) particles is very important, and you are also right in thinking that they are saving this for a later paper. This growth process after nucleation is what bridges the connection between nucleation and CCN. They will do an entire new set of experiments to look at how these growth processes. In this first paper, they did a tremendous number of experiments to determine this information about nucleation (and time at CERN is very limited).
In my group, we’ve theoretically calculated that the change in CCN due to cosmic rays is significantly smaller than the change in nucleation due to cosmic rays. For example, lets say that between the solar max and solar min, nucleation rates increase by 10%. We now have 10% more 1 nm particles, and these particles are all competing for condensible material (sulfuric acid and organics) so they can grow to larger sizes. Thus, the particles grow more slowly when nucleation is increased (all else fixed) Generally the smallest particles are lost by coagulation (colliding with other particles) more quickly than larger particles, so by keeping these particles small for longer, they are more likely to be lost by coagulation. Finally, coagulation will also increase due to the increase in the total number of particles. Thus, we find CCN increase by significantly less than 10%.
Since (as far as I know) only theoretical calculations of this growth exists, it will be great to see what the results from the CLOUD experiments on aerosol growth show. They may confirm our calculations, or they may find that there were some physical details that our model was not capturing.
“… the seriousness of this global problem has been recognized by all nations of the world …. Although the cause-effect relationship is very clear, for the layperson as well, it is depressing to see that it is, nevertheless, not accepted by a small group of very vocal critics without any record of achievements in this area of research. Some of these have recently even succeeded in becoming members of the U.S. Congress.
AND THINGS COULD HAVE BEEN MUCH WORSE
… I can only conclude that mankind has been extremely lucky …. we should always be on our guard for the potential consequences of the release of new products into the environment. Continued surveillance of the composition of the stratosphere, therefore, remains a matter of high priority for many years ahead.”
“… it appears that ion-neutral reactions occur in the upper atmosphere to produce polycyclic aromatic hydrocarbons (PAHs) as well as heterocyclic compounds involving nitrogen…. methane, cyanogen, benzene, and other organic molecules up to 100 daltons…. larger molecules such as naphthalene, anthracene derivatives, and an anthracene dimer…. heavy negative ions, with masses up to 8,000 Da, probably produced by aggregation of PAHs.
‘These very large organic molecules in the upper atmosphere indicate there’s a complex ion-neutral chemistry going on that really hasn’t been considered much before,’ says Caitlin Griffith, an associate professor of planetary atmospheres at the University of Arizona.
Those massive negative ions—no longer in the gas phase, as compounds heavier than about 2,000 Da become aerosols in Titan’s atmosphere—then likely lose altitude, becoming condensation nuclei for supersaturated benzene and other components of Titan’s atmosphere. As the particles grow and react, eventually they might become tholins, large hydrocarbon-nitrile particles thought to produce Titan’s orange haze….
Seems like any variation in the solar/interplanetary magnetic/cosmic ray environment ought to show up in Titan’s atmosphere.
So, based on fig S4, one can say that the CLOUD experiments shows that cosmic rays seeds aerosols that grow into CCN:s, though the question is still out whether this process has any relative importance compared to other ways to grow CCN:s (hope I got that right). It will be interesting to read coming papers from CLOUD!
Again, you refuse to understand my point. First, I said nothing about NOx, I mentioned only NO2. The sulfuric acid concentrations during the CERN experiments were on the order of 0.1 ppb. There is far more sulfur dioxide than that in a normal atmosphere. At relative humidities above 20%, NO2 will oxidize that sulfur dioxide quickly and completely to sulfuric acid. The CCN available to create cloudiness will be at least an order of magnitude higher than that used during the CERN experiments. Plus, CERN did not include other, naturally occurring particles.
It seems certain that the ionization effect will be far greater than that which occurred during the CERN work.
[Response: NOx is the sum total of NO and NO2 and since these species are almost always in equilibrium with each other (depending on sunlight/ozone etc), it is a normal shorthand to talk about NOx rather than each species individually. As for ambient concentrations of H2SO4, other sources suggest 10^7 molecules per cm3 - right in line with the CLOUD experiments. But if you have better information, provide some links - this is not my area of expertise and so I'm happy to learn (and please turn down the snark; it is not an inducement to engage). - gavin]
Comment by Snorbert Zangox — 1 Sep 2011 @ 10:48 AM
SO2 is oxidized in the gas phase by the hydroxyl radical (OH) and in the liquid phase (i.e. cloud droplets) by H2O2 or O3 if I remember correctly, dependent on pH. NO2 may play a role here as a precursor to ozone.
the reaction rate is ridiculously small, and will never matter. The only known and well-established gas-phase oxidant of SO2 in the atmosphere is OH, as Bart pointed out – though there may be a couple of others in some circumstances. But not NO2 (or NO3 for that matter). NO2 *does* help regenerate OH consumed in hydrocarbon oxidation in polluted conditions, by acting as a O3 precursor. (O3 in turn is needed to produce excited-state oxygen atoms which react with H2O to give 2 OH). Perhaps this is what has confused you? But this will not really affect CLOUD results. (Incidentally, SO2 in the atmosphere normally has a lifetime on the order of days, so your claim of “quick and complete” conversion to H2SO4 is anyway incorrect, in addition to the fact that you have got the chemistry wrong.) I suggest taking a look at an atmospheric chemistry textbook, e.g. Dan Jacobs book:
Isn’t there a kind of Liebeg’s law for cloud formation, in that if there isn’t enough moisture to (super)saturate the air, then it doesn’t matter how many GCRs, SO2, H2SO4, PAHs, soluble/insoluble/amphoteric/surfactant organics, or pixie dust is in the air, there won’t be clouds magically formed(well, maybe with pixie dust &:>)? Also, decreases in CCN formers in clear sky won’t cause negative cloud formation.
Conversely, if there’s enough water vapor but not enough CCN precursors, or less active precursors, then the level of supersaturation will have to go higher to start cloud formation. But, with DMS from plankton, and dust from the Bodélé Depression and other desert areas(which stimulate plankton when they rain out into the ocean), plus particulates from biomass burning and anthropogenic sources, and GCRs which have fluctuated only about plus or minus 10% since at least the 60′s, lack of CCN precursors are less likely (IMHO) to limit cloud formation – which puts nonlinearities into the process.
It also seems to me that more GCRs might lessen cloud cover by increasing the rate of particle coalescence into rain. For every positive ion that’s created when an atom gets smacked by a cosmic ray, there’s a free electron that will want to attach itself somewhere. Both positive and negative charges will create mirror surface charges on conductive liquid particles, and most cloud particles will have acid, or salts dissolved in them. Once a particle acquires a net charge, it will attract other charged particle of the opposite sex, and through charge mirroring, neutral swinger particles that can go both ways. More charge pairs at high GCR rates might make the process of coalescing into rain more efficient and faster, reducing the amount of cloud “in the pipeline” between cloud formation and precipitation.
If atmospheric co2 enrichment enhances the growth and reproductive abilities of the biosphere there must also be an increase in BVOC’s from the whole system. e.g. more DMS from phytoplankton and the huge amount of additional VOC from man made conifer plantation in the form of isoprene and terpenes and the rest;-
“Bvoc’s constitute “one of nature’s biodiversity treasures.” Comprised of isoprene, terpenes, alkanes, alkenes, alcohols, esters, carbonyls and acids, this diverse group of substances is produced by a variety of processes occurring in many plant tissues.”
and also solid particulate material (with the potential to form CCN), for example more pollen from healthier green photosynthesising plants and waxy leaf particles after decomposition.
This additional aerosol loading could and should be taken into account.Is it Anthropogenic in origin,due to our co2 enrichment,although it is from natural sources?
Ionisation by space energy and chemical reaction from solar light energy etc. just has more stuff to play with due to Humans putting more stuff in the atmosphere.
Does this hold water?
[Response: Possible but very difficult--practically impossible I'd guess--to demonstrate. You have many other factors affecting global plant biomass that would likely swamp out any such effect, land use/cover change being the biggest such. Also, CO2 fertilization does not necessarily lead to higher amounts of biomass--it likely leads to higher NPP, but that is a rate not a pool, and it doesn't even necessarily do that, depending on the status of various other potentially limiting factors, climate conditions and such--Jim]
Brian Dodge @136 — In my amateur understanding, it suffices to have saturation has there always seems to be enough CCNs (except possibly in interior Antarctica, where it doesn’t matter). So until there is so much water vapor that CCN availablity becomes some form of limiting factor it suffices to just consider the water cycle. Now availability must be very high indeed when one considers the precipitation rates in parts of Pakistan in the summer of 2010.
Many different projects under that umbrella. One small excerpt follows:
The GLOMAP modelling project (led by Ken Carslaw) has, for the first time, quantitatively linked the seasonal cycle of cloud condensation nuclei (CCN) in the marine boundary layer with DMS dynamics using a global aerosol microphysics model. The sensitivity of CCN to local DMS emissions is lower (but the effect more widespread, over thousands of km) than previously thought due to long range transport of aerosol through the global free troposphere (see Achievement 3.3).
GLOMAP also found that there is a significant source of marine organic aerosol (comparable in magnitude to the fossil fuel organic carbon source), and that stratospheric ozone depletion has driven increases in southern hemisphere winds – leading to increased sea spray, aerosols and CCN concentrations. The change in summertime forcing of – 0.7 W m-2 is comparable in magnitude, but opposite in sign, to the greenhouse gas forcing over the same period…..
Makes me again wonder why the CERN physicists were surprised to find they might need more than nitrogen and sulfur to make clouds. Oh well, nobody can read everything.
In terms of whether or not -25C I think I recall that Svensmark et al could only a correlation of GCRs with low clouds. If this is so then the larger lab CLOUD results at -25°C is not what we’re seeing?
Comment by charles "chick" keller — 3 Sep 2011 @ 11:03 PM
Hank et al,
the following paper is relevant to what you’re discussing:
“A review of natural aerosol interactions and feedbacks within the
Not Lieberg’s law as such, but rather a rate constant, or underlying both, the principle of detailed balance. It ain’t magic. Reactions consume reactants in given proportions. The proportion that is lowest wrt that ideal proportion limits the reaction. CCNs are not the limiting factor in cloud formation. Svensmark would have flunked P Chem.
Snorbert Z.: “It seems certain that the ionization effect will be far greater than that which occurred during the CERN work.”
I would put that right by the Nicean Creed as a statement of faith…well except the Nicean Creed would probably have more scientific basis. Dude, please crack an elementary chem text. Look at some reaction rates. Sheesh!
Has any possible cloud seeding by co2 molecules been considered?
(the unsubtle gist of my question should be obvious)
In the initiating post at top: “… and that given that change in cloud properties, you would need to show that it had a significant effect on radiative forcing”
My understanding of the paper is that it shows that ionisation can increase cloud formation. If that applies to low level clouds, then does not the upwardly reflective effect of clouds simply reduce incident energy on earth surface? In which case, is not effect on radiative forcing irrelevant?
Last, heat moves from a hot body to a cold space. The earth core is at 7000 deg c. Heat must pass out through the oceans and air and eventually into space. Nuclear events and heat generation within the earth may be as variable as sunspots. I don’t believe there is much data on this. Do Climate models assume earth heat emission to be constant?
Questions are, by definition, never heretical. But sometimes they are confused or irrelevant. Let me try some layman answers.
1. CO2 gas molecules are some three orders of magnitude smaller than cloud condensation nuclei (CCN). The CO2 that is, in fact, used in cloud seeding takes the form of dry ice crystals.
2a. Your understanding of the paper is wrong. It does not show that ionization can increase cloud formation, but that it can increase nucleation. As the original post pointed out, there are several steps from there to increased cloud formation.
b. A change in cloud reflection to space is a radiative forcing.
c. Yes, low clouds tend to cool the planet (in daytime), high clouds to warm it. The paper does not show that there will be more clouds, or if there are, that they will be low.
3. Geothermal energy changes on geological timescales. Anyway, it heats the planet with some 0.08 W/m2, five orders of magnitude less than solar and two orders of magnitude less than the forcing from a doubling of CO2.
CM thank you for the corrections, especially on the definition of radiative forcing.
Co2: forgive my natural curiosity. Has there been any study of whether free CO2 molecules have any tendency to clump into crystals at the low temperatures of higher altitude?
Re earth heat transfer: geothermal energy changes on geological timescales. Heat transfer is a constant 0.08 W
/m2. Understood. Do climate models include consideration of shorter period heat releases such as from submarine volcanoes?
I am a fervent reader of this blog as well as skeptic blogs such as Climate Audit and Watts up with that. I am also a follower of Richard Lindzen’s work as well as a few other skeptical climate scientists. I am looking for help to better understand the nature of the science behind positive forcing from CO2.
Here is what I have trouble with as a scientist who is outside of his field and lacks detailed knowledge of many of the intricate and complex topics within this field. I don’t understand how the scientific method, the only tool we have at our disposal to determine cause and effect relationships, is used when climate modellers asses the impact of CO2 on cloud formation, water vapour and other known factors that effect climate sensitivity. The recent work out of CERN as well as some of Gavin’s posts give me more doubt about the methodology. Here is why:
In a recent paper by Richard Lindzen he claims that if one were to take into account just the effects of CO2 without the potential impact of CO2 on other factors that a doubling of atmospheric CO2 would cause a 1 degree C global temperature increase. However, most models predict the impact of CO2 to be much larger due to its influence on other factors. On what bases methodological bases are these predictions made and by what measure are they tested? If, as the CERN study demonstrates, there are unknown variables that contribute to cloud nucleation where does one gain confidence in scientist’s ability to make predictions about the effect of increased CO2 on cloud formation in the real world. There is no process by which it is possible to test the effects of CO2 on cloud formation or water vapour in a system we don’t fully comprehend and have no ability to control. In other areas of science the bar to be able to make a publishable claim seams to be set much higher.
Moreover, as Gavin has said repeatedly, we have no idea what the feedback is of cloud formation on temperature change. Jury is still out. Yet it is these unknown variables that are determining the predictions of CO2 on global warming. It is precisely these mechanisms that are being used to predict feedforward warming from CO2.
What type of science is there (and where can I find it) to demonstrate to me why I should believe that a double of CO2 will produce more than a 1 degree C temperature change? What is Eric so certain about?
[Response: Many things can affect climate. Let's take an extreme example - a big asteroid like the one at the end of the Cretaceous. Now there are obviously many unknowns about exactly what happened. But those unknowns don't impact our understanding of the role of CO2 (or ozone, or volanoes or solar changes, or land use change etc.) one jot. There is no zero sum game that says that the more we understand about driver X, the less we understand about CO2. The CERN experiments were related to aerosol nucleation and do not impact the constraints on climate sensitivity at all (if you disagree, please show me the paper that uses knowledge about aerosol nucleation at the nanometer stage as part of the argument for climate sensitivity). They are different issues. - gavin]
Richard: CO2 clustering has been speculated to play a role in cloud formation *on Mars*, and hence has been studied quite a bit. As illustrated in the link by Hank Roberts, temperatures anywhere in the Earth’s troposphere are too high for this to occur.
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..”. http://press.web.cern.ch/press/pressreleases/Releases2011/PR15.11E.html
Not an excuse, just an observation.
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!
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.
#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.
Comment by Pete Dunkelberg — 6 Sep 2011 @ 10:39 AM
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?
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.
> 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.
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?
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…”
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.
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.
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.
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?
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?
#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.
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?
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.
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.
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 (http://www.atmos-chem-phys.net/11/9089/2011/acp-11-9089-2011.html) 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 (http://www.agu.org/pubs/crossref/2010/2009GL041327.shtml), but I don’t know anyone who has followed up to see how important these effects are.
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. ). 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 .
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]
“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…
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.
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.
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]
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.
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.
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.”
A bit of history on the assay described above: http://www.sciencedirect.com/science/article/pii/S0304420303000987
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.
“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.”
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.
“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 http://www.inco-sudbury-airquality.com/ERPOverview.htm
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.
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. http://en.wikipedia.org/wiki/SNO
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.
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 (http://en.wikipedia.org/wiki/Albedo) or BDRF (http://en.wikipedia.org/wiki/Bidirectional_reflectance_distribution_function) and the Callendar Effect. (http://en.wikipedia.org/wiki/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 (http://en.wikipedia.org/wiki/File:Jetcrosssection.jpg) 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$?
Comment by Gordon Jenkins — 17 Sep 2011 @ 11:38 PM
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.
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?)
“…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).
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?
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.
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 where T is the temperature anomaly, c is a heat capacity, F is the applied forcing from 1950 on and is the sensitivity. The solution is , the warming rate is (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]
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 , 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.
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.
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…
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.
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]
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?
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!
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.
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:
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]
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]
Re-Gavin’s Response: 1 Corinthians 13:1-13 -ἀγάπη in full context.
“Omnia vincit amor, et nos cedamus amori” -Virgil, Eclogues X.69
Comment by Gordon Jenkins — 22 Sep 2011 @ 10:50 AM
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.)
- 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 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]