Statistics

Cosmic Radiation, Clouds, & Global Warming

Rumor is that James Hansen was so upset by CERN’s CLOUD experiment results that he and a gaggle of rabid environmentalists stormed the White House and demanded that cosmic rays be outlawed. Or something: it is always difficult to say what is on the collective mind of a mob.

Anyway, Hansen was shuttled off to the cooler and hasn’t been heard from since. And as of this morning, there is still no word from the White House on how cosmic rays could be blamed on George Bush.

Why the fuss? Jasper Kirkby and a swarm of co-authors from CERN have just seen their “Role of sulphuric acid, ammonia and galactic cosmic rays in atmospheric aerosol nucleation” published in Nature. Jasper Kirkby and CLOUD

What Kirkby and his colleagues did was to build a tinfoil-wrapped container in which they simulated an artificial, high-altitude atmosphere in the lab. They let this replica atmosphere be bombarded by cosmic rays and noticed that cloud nuclei were created in the process. Why bother?

This: “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 ammonia.”

The official synopsis (read it!):

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.

Translation: cosmic rays cause clouds. Clouds, depending upon where and when they float, both cool and heat the climate. Ipso facto, cosmic rays affect the climate.

What is a cosmic ray? A ray whose origin is cosmic. I.e., a ray born in space, a region which includes the sun and beyond, and whose existences owe nothing to mankind. That is a long-winded way to say that our climate is, at least in part, regulated by forces completely outside political control.

So it curious that in its editorial accompanying Kirkby et al.‘s paper, Nature said, “Scientists on both sides of the debate welcome the findings, although they draw differing conclusions.” Do they? Welcome it, I mean.

There is already a “flap” over the comments of CERN’s director-general Rolf-Dieter Heuer:

I have asked the colleagues to present the results clearly, but not to interpret them. That would go immediately into the highly political arena of the climate change debate. One has to make clear that cosmic radiation is only one of many parameters.

It is clear that cosmic radiation is, as Heuer says, one of many parameters. But it is far from clear just how important this parameter is. Is it the predominate driver of climate? A bit player? To say requires interpretation, which Heuer supposedly forbade.

But don’t let’s be too hard on Heuer. Another view of his advice is that his comments were fatherly, purely protective. I can tell you from personal experience how one’s career can be sunk into the toilet when one dares go against “the” consensus. Best to publish the results with no commentary and save yourself a ton of grief.

Too, these experiments were in the lab, not in situ. To say how cosmic rays influence the real climate will require observations on the actual atmosphere: expensive and time-consuming observations. The last word is not yet.

Still, old hands in climate science will recall the IPCC’s first report (AR1) eschewed entirely the sun’s role in the climate. The sun was just a bright yellow orb, supplying a constant, fixed, unvarying amount of radiation to Earth. Any changes in the climate caused by non-humans were due to orbital variations, and even these were barely worth mentioning.

Each subsequent report allowed a little more respect to the sun, but extra-human causes always played a minority role. It will be fascinating to see how “the” consensus incorporates CLOUD into AR5.

Best guess is that it will garner a footnote, possibly a sentence or two. The excuses for largely ignoring it will be two: as noted the experiments were in the lab and not the real atmosphere, and climatologists will not have had sufficient time to incorporate better cloud physics into their models. It’s a lot of work, you know.

So, while we’re waiting for more experiments and improved models, it’s better to be safe than sorry and claim that models that exist are more than good enough. That “tipping points” are just around the corner. That it’s “worse than we thought.” That “the science is settled.”

Anybody care to bet against me?

Categories: Statistics

39 replies »

  1. Call me naive, but I still believe science is like capitalism: in the long run, it works. Climate science is in the equivalent phase of a financial crisis. Let’s call it a science crisis. Lot’s of uncertainty, calls for government intervention, reports that it doesn’t work. But one paper after another, a chip off the climate alarmist monument will fall. History is full of examples where science intially gets it wrong. What makes it dependable is time, which we have not had enough of so far.

  2. NASA’s global warming website lists uncertainties associated with clouds as the third ranked item of uncertainty; and, the #1 uncertainty regarding factors that fall in the “forcings” category. See: http://climate.nasa.gov/uncertainties/ Note that NASA references the IPCC as a source for the uncertainties.

    Solar irradiance is, still, #1 for uncertainty. Aerosols, dust, soot, etc. are #2 for uncertainty. What the recent CLOUD experiment results suggest, maybe, is the possibility that certain chemicals associated with this subcategory may be a dominant/significant factor (more experiments will tell). Whether the significant particles associated with Clouds/Cosmic Rays are of natural or human origin appears unknown with any certainty. For now.

    However, read RealClimate & any number of other references & one has little or no difficulty in finding “settled science” being presented for clouds/cosmic ray influences. Also, that any further experimentation in this area has been denounced as unnecessary (such was there, anyway, perhaps since deleted or retroactivey edited to fit the latest findings…). Solar irradiance has been denounced as a factor of any significance by these groups as well…except it isn’t (unless NASA is wrong–both in listing it and in attributing it to the IPCC’s report). Etc.

    In finding such blatant areas of significant uncertainty the average layperson ought not have it so easy via a quick internet search….which really says something….

  3. RE: That “tipping points” are just around the corner. That it’s “worse than we thought.” That “the science is settled.” Anybody care to bet against me?

    According to who/m is the above true (that’s a rhetorical question meant as a bit of a joke, by the way)?

    According to NASA, the IPCC has stated (see http://climate.nasa.gov/effects/ ): “The IPCC predicts that increases in global mean temperature of less than 1.8 to 5.4 degrees Fahrenheit (1 to 3 degrees Celsius) above 1990 levels will produce beneficial impacts in some regions and harmful ones in others. Net annual costs will increase over time as global temperatures increase.”

    Yes, costs will rise as people adapt. And people WILL adapt…but maybe not the environmentalist whackos. With seas flooding our shores at the rate of millimeters per decade most people will be able to make suitable modifications, or just plain get out of the way in plenty of time. Heck, even after WW-II, which much of Europe decimated almost, literally, overnight people & society rebounded smartly. We humans are an adaptable bunch.

    However, the environmentalist whacko is a particular breed much like that ficticious security cop in the Austin Powers movie that couldn’t adapt his duties to a slow approaching steamroller: http://www.youtube.com/watch?v=qLlUgilKqms

    Perhaps their grim outlook of dire consequences isn’t so much one of noble concern for the population & society & planet overall, its their deep sinking feeling that change is happening & they are emotionally ill-equipped to cope with “change” and are intimidated by those of us that find such “change” just another challenge, and a minor one at that, to overcome.

    Any doubt, recall Bill Clinton’s presidential campaign in which vague “change” was harped on something to not fear … then B. H. Obama’s similar endorsement of his brand of ill-defined “change” that was/is clearly a move backward to the familiar.

    And note that nowhere will you hear/read the enviro-whackos espousing positive changes assocated with adapatation. All emphasis is on restoring a particular status-quo.

    To a person, these are frightened, timid, neurotic, pathetic specimens of humanity that would tear everyone down to their level rather than try to improve their self-esteem.

    In management one sees the equivalent routinely and the old saying sums up: “A” people hire “A” people (i.e. people that may be better in some respects than they are) while “B” people hire “C” people, etc. The global warming alarmist bunch is, to a person, socialogical failures–“F” people per old saying analogy. Read about them in: “The Liberal Mind: The Psychological Causes of Political Madness,” available for an inexpensive download at: http://www.libertymind.com . Chapters 42 or 43 thru 46 summarize their miserable psychology. So far, 100% of the people I know that read this confirm it explains, with predictive accuracy, what & why of such folks they know (e.g. family members, neighbors, co-workers, etc.).

    Anyway, getting back to the bet…here’s mine: invest in companies that make Seersucker suits. And hats. Also, Canadian wines seem like a good prospect (some in Ontario, just outside of Buffalo, NY, are particularly good). Wines have a double-benefit: if they don’t rise in value they provide very nice consoling effects when consumed.

  4. Ken: Interesting saying about A people. My personal observation has been that people hire people who are in some way in their own image. We create our own echo chambers, and dumb-asses hire dumb-asses. Compare the US Government employees with Google employees.

    Briggs: That’s not a good bet. You are part of my echo chamber, and I generally agree with you. I guess it is a rhetorical bet.

  5. Pipelines, cosmic rays, those are just excuses. Hansen was just reliving his college days. Given the chance, I’d hang out with Darryl Hannah, too.

  6. It is clear that cosmic radiation is, as Heuer says, one of many parameters.

    Not one of the parameters used in the GCMs, I’d guess.

    Re: in situ
    When I see that an experiment is performed in situ, I picture one done while seated on the porcelain throne.

    Best guess is that it will garner a footnote, possibly a sentence or two. More study is required. Send money.

  7. In high school I made a cloud chamber as a science fair project. The cosmic rays would leave condensation trails as they traveled through the saturated atmosphere. You would expect the cosmic rays to have the same effect in the upper atmosphere. Wator vapor (gas) is about 2/3 the density of oxygen and nitrogen gases, so it heads for the stratosphere. That’s why when you are flying at 37,000 feet you can see clouds thousands of feet above you.

  8. I’m sure you’d agree that one of the big problems with climate science, whatever you think of AGW, is the tendency to overstate the implications and even the results of published research if it can be linked to AGW. I don’t really understand why you choose to do the same, whatever the value of your broader point.

  9. Bob, I suspect that if you really thought about it, or had some objective way to measure it against the relevant criteria, you’re observation that “dumb-assess hire dumb-asses” would be consistent with/could be refined more precisely as “dumb-assess hire even dumber dumb-assess” along the lines of the ‘A’ hires ‘A’ & ‘B’ hires ‘C’ pattern. Its not just an echo chamber dumb-asses strive for, they also endeaver to “elevate” themselves via the tried & true tactic of surrounding themselves with even more dimwitted dumb-asses to make themselves look “taller” by comparision.

  10. The correlation between solar activity and global temperature has been know for decades – as an example, see:

    http://www.tmgnow.com/repository/solar/lassen1.html

    Now one probably doesn’t need to point out to visitors to this site that correlation does not equal causation, but when there’s a strong theoretical basis to connect two phenomena, one can be forgiven strong suspicions.

    As many (but perhaps not all) on this site know, solar activity (primarily as measured by sunspot occurence) affects the earth’s magnetosphere, which then affects the flux of cosmic rays, which (as this paper seems to indicate) affects cloud formation, which of course affects global temps.

    One can easily see graphically the correspondence between global temperature and solar activity in Lassen’s paper cited above; I’ve never seen any substantial correspondence (on the same time scale) between anthropogenic carbon dioxide and global temperatures.

    And I guess according to a prominent Nobel laureate that makes me the modern day equivalent of a racist.

  11. Jasper Kirkby’s CERN lecture regarding the then planned ‘CLOUD experiment’ is at:

    http://cdsweb.cern.ch/record/1181073/

    One can download the appx. hour long lecture that presents a very apparent close correlation between cosmic rays & climate very clearly. The now ongoing CLOUD experiment(s) are beginning to objectively quantify & correlate specifics.

    At this point the CLOUD findings, while not conclusively showing cosmic ray-induced cloud nucleation forming more clouds is a major factor, the findings also don’t rule out that possibility…and…they do somewhat precisely confirm some cosmic ray/cloud formation relationships.

  12. It’s Kirkby, not Kirby. And no, his results do not show that “cosmic rays cause clouds”. This is what Jasper Kirkby himself says about the Nature letter that summarizes his team’s work:

    http://www.nature.com/news/2011/110824/full/news.2011.504.html

    The high-energy protons seemed to enhance the production of nanometre-sized particles from the gaseous atmosphere by more than a factor of ten. But, Kirkby adds, those particles are far too small to serve as seeds for clouds. “At the moment, it actually says nothing about a possible cosmic-ray effect on clouds and climate, but it’s a very important first step,” he says.

    There’s still a long way to go before the experiments confirm as much as a tentative GCR-CCN connection, not to mention actual significant influence of GCR on cloud formation and a resulting radiative forcing capable of driving climate change. Your article is a misrepresentation of science.

  13. All,

    I beg Mr Kirkby’s pardon. His name is now spelled properly.

    Grzegorz Staniak,

    I am now representing science faithfully.

  14. I am now representing science faithfully.

    No, you’re not. The main author of the paper in question says:

    At the moment, it actually says nothing about a possible cosmic-ray effect on clouds and climate.

    You, on the other hand, in direct contradiction to him, claim that the paper proves that “cosmic rays cause clouds”. Let me quote from the paper:

    “Ion-induced nucleation will manifest itself as a steady production of new particles that is difficult to isolate in atmospheric observations because of other sources of variability but is nevertheless taking place and could be quite large when averaged globally over the troposphere. However, the fraction of these freshly nucleated particles that grow to
    sufficient sizes to seed cloud droplets, as well as the role of organic vapours in the nucleation and growth processes, remain open ques tions experimentally.
    ” (emphasis mine)

    Until you provide arguments on which you base your claims contradicting Jasper Kirkby et al, the article above remains a gross misrepresentation of scientific research.

  15. Grzegorz Staniak,

    No need to shout, old boy. Can you point to the exact words in my summary where I evince a “gross misrepresentation of scientific research”?

  16. Oh, sorry for the stress, but it seems somehow you missed the quote from Kirkby the first time. And for some reason you want me to point out the misrepresentation of research for the third time? Twice is not enough?

    You say: “Translation: cosmic rays cause clouds. Clouds, depending upon where and when they float, both cool and heat the climate. Ipso facto, cosmic rays affect the climate.“.

    Jasper Kirkby says: At the moment, it actually says nothing about a possible cosmic-ray effect on clouds and climate, and, in the paper: the fraction of these freshly nucleated particles that grow to sufficient sizes to seed cloud droplets […] remain open questions experimentally.

    The above directly contradictory opinions cannot both be true at the same time. Kirkby et al. haven’t even started to show a link between the observed ion nucleation and the formation of cloud condesation nuclei (CCN) — ’cause you know, old buddy, these are two quite different things actually. Unless you present an argument that justifies the use of the words “cosmic rays cause clouds” in the description of Kirkby et al. results, this is still a gross misrepresentation of scientific reserach.

  17. Grzegorz Staniak,

    No stress here. I said that “cosmic rays cause clouds.” And Kirkby implies cosmic rays cause clouds, but says we’re uncertain how many. And then I said, “That is a long-winded way to say that our climate is, at least in part, regulated by forces completely outside political control” and finally “The last word is not yet.”

    So again I ask, where is it that I evince a “gross misrepresentation”?

  18. I said that “cosmic rays cause clouds.” And Kirkby says cosmic rays cause clouds.

    No, actually he doesn’t. Please refer me to anything in the paper that allows you to say so. And no, ion nucleation is not enough. As I said, the study doesn’t even start to show a possible connection between GCR and cloud formation. Jasper Kirkby knows this, but apparently you know better. Please point to a passage in the paper that can really be translated as “cosmic rays cause clouds”.

  19. Grzegorz Staniak,

    Perhaps it is a question of English. When our boy Kirkby says “the fraction of these freshly nucleated particles that grow to sufficient sizes to seed cloud droplets […] remain open questions experimentally” this implies that cosmic rays cause clouds, but we don’t know how many. That is my summary of the words, which is fair. Certainly not a “gross misrepresentation.”

    Added: I think you have the idea that Kirkby is saying cosmic rays do “not” cause clouds. If so, that would be a misrepresentation. It would also be false.

  20. this implies that cosmic rays cause clouds

    No, it doesn’t…

    but we don’t know how many

    … because this could for example be zero, right? That’s not been researched yet, and this means we have no knowledge of this, and this means we cannot responsibly say things like “cosmic rays cause clouds” to describe the results in question. And this means that saying so remains a gross misrepresentation of scientific research.

    Please do not evade the question. You have Kirkby’s own words: it actually says nothing about a possible cosmic-ray effect on clouds and climate. You claim otherwise. On what basis?

  21. Grzegorz Staniak,

    Well, I give up trying to convince you. It is plain that cosmic rays do in fact affect the climate, even though Kirkby says the paper is not directly about this. It is almost a trivial truth. It is an open question how much. And that’s that.

    Is there are reason you’re not happy with that conclusion? Did you buy stock in some company which relies on “green” funding?

  22. “Rumor is that James Hansen was so upset by CERN’s CLOUD experiment results that he and a gaggle of rabid environmentalists stormed the White House and demanded that cosmic rays be outlawed. Or something: it is always difficult to say what is on the collective mind of a mob.”

    I have it on good authority that this is nonsense.

    Just to make things clear, the lead author of the CERN CLOUD paper said that it “actually says nothing about a possible cosmic-ray effect on clouds and climate”.

  23. Where exactly “it is plain”? What exactly have you read in the paper that entitles you to summarize it as “cosmic rays cause clouds” while its main author claims that “it actually says nothing about a possible cosmic-ray effect on clouds and climate”? Will you answer the question, or will you continue the arguments ad hominem, broken here and there with allusions to unidentified and mysterious “trivial truths” that aren’t? You know that solar activity/GCR don’t even correlate with temperatures, right?

  24. Grzegorz Staniak,

    My dear, given the evidence from Kirkby’s paper, and given all the other knowledge we have of physics, it is trivially true that cosmic rays affect climate. It is wholly unclear by how much.

    Now I want you to make a direct statement and either admit the truth of this, or say, “Cosmic rays do not affect climate.” After you do either, we shall be done, because if you admit the truth of my statement we no longer disagree, or if you make the statement in quotes, we will disagree and I will have nothing further to say to convince you.

    UPDATE: 4:58 PM, PST. I’ll be away from the computer the rest of the day.

  25. Please refer me to a publication in reviewed literature that proves within any accepted theoretical framework that “cosmic rays affect climate”. Sorry, but “trivially true” is not enough, especially as it is simply neither trivial, nor true.

    Now, I’m not really interested in what you want me to do, although I understand your urge to evade uncomfortable questions and put the onus on somebody else. You started with “translating” Kirkby’s article as “cosmic rays cause clouds”, which is simply a gross misrepresentation of the results. You completely ignore Kirkby’s own words that directly contradict your opinion, and you are unable to point to anything in the article that would justify it. Now it’s just “trivial truths” and “knowledge of physics” that allow you to merely infer that Kirkby must have intended to say something he expressly denies to have said. Call me strange, but no, somehow I’m not convinced.

    In case you decide to get back to the computer later, I’ll be here.

  26. I disagree with the idea that people hire people in their own image. Managers in successful corporations hire people using the following two criteria among others. Is the applicant brighter that the person doing the hiring and can he/she replace the first line manager if that person gets promoted? The reasons people are selected using these two criteria (among others) are that someone doing the hiring wants to get promoted and must have a replacement, and the hiring boss needs people working for them that are smarter than they are to look good in carrying out the objectives of the corporation unit. Of course, these criteria are not always used because hiring people smarter takes courage.

  27. Staniak,

    were you interested that Kirkby told the climate modelers that they were wrong?? That based on his Cloud experiment they did NOT know what causes clouds??

    How can they project climate, and especially short term regional climate, if their precip and clouds are so far off???

    Bud, I don’t care if you don’t think water vapor is involved in clouds and rain. The models are so bad even you shouldn’t have to put up with them!! The fact that the correlation between solar activity and temperature is much stronger than CO2 concentration just goes to show how believers like you are blatantly anti-scientific and biased against any other research.

  28. I’ve got no reason to know anything about how confident Kirkby is that the unknown fraction that grow big enough to seed clouds isn’t negligible, but I think giving “cosmic rays cause clouds” as a ‘translation’ of the synopsis is enough of a stretch to be called misrepresentation, whatever else there is to justify it as a conclusion in itself.

    But the part that was clearly wrong was before that – “They let this replica atmosphere be bombarded by cosmic rays and noticed that cloud nuclei were created in the process.”

  29. @kuhnkat

    People claim that “climate modellers are wrong” like, a thousand times a day. But it’s one thing to just “tell” this, and quite another to prove it. Jasper Kirkby has a personal history of bold claims like that, but there’s actually nothing inherently wrong with an ambition to prove something important — as long as you know that ultimately you have to put up or shut up. The experimental results that Kirkby’s team obtained are just a fragment of one first point out of four that have to be proven in order to show that GCRs exert a significant influence on Earth’s climate. They definitely don’t say anything like “cosmic rays cause clouds” — hence his own words to this effect.

    As far as the rest of your post is concerned, you’re profoundly mistaken. CLOUD is not a pioneering experiment that shows for the first time how clouds are formed. It’s just research into one possible aspect of cloud formation — it’s needed, it’s welcome by all who publish in the field, but it’s not necessarily very important (there’s evidence showing that a potential GCR influence is dwarfed by other cloud forming mechanisms). Yes, it’s true that clouds are a tricky part of climate modelling, but not for the reasons that you mention. And no, there’s no correlation between temperatures and solar/GCR activity in the last 50 years. If you want to prove otherwise, it takes much more than just arbitrarily declaring that “the models are so bad”.

  30. I’ve enjoyed, for awhile, the semantics debate between W.B. & G.S. …. and can’t help but marvel at some remarks…like “CLOUD is not a pioneering experiment” — given that before it there’s been nothing remotely close. And, “it’s not necessarily very important…dwarfed by other cloud forming mechanisms).” given that:

    a. NASA & the IPCC agree, vehemently, that our understanding of clouds & cloud formation is a major, perhaps THE major, uncertainty in feedbacks associated with global warming mechanisms (recall: http://climate.nasa.gov/uncertainties/ ).

    b. J. Kirkby, et. al. (its a pretty impressive international team involved, you know) has made other statements re cosmic rays & the formation of nucleates that “seed” clouds — what some here summarize, perhaps imprecisely (but not really incorrectly) as ‘cosmic rays form clouds.’ Recall his & others related publications & his lengthy lecture at: http://cdsweb.cern.ch/record/1181073/ The latest CLOUD experiment data does support that lecture, though not in the precise chemistry; or, put another way, the latest CLOUD experiment data does not refute the basic mechanism, though details likely vary–and in subtle ways.

    Given that we (any person in particular & all of humanity in general) as a superficial understanding of clouds, it naturally follows that any modeling of them is inherently speculative. Some would say, with compelling support, that when such speculation is predominantly based on ignorance, such models are “wrong.”

    Though they might get lucky. The evidence of their universal omission of predictive qualities, such as the past decade’s nearly absent warming (or slight cooling, depending on where one looks) strongly supports the conclusion that the models are “wrong.”

    A model’s failure to predict substantive & long-term trends is poor evidence of its correctness.

  31. I was under the impression that cosmic rays were already regulated years ago as a potential carcinogen

  32. @Ken

    You quote selectively. “…not a pioneering experiment that shows for the first time how clouds are formed”. I guess that’s what kuhnkat meant when (s)he said “they did NOT know what causes clouds”. And that’s certainly not the case. Kirkby’s results don’t explain cloud formation as such, they only attempt to show how much of an influence can GCRs be over the predominant cloud formation mechanisms.

    NASA & the IPCC agree […] that our understanding of clouds & cloud formation is a major […] uncertainty in feedbacks associated with global warming mechanisms

    That’s actually what I said above — I just added “…not for the reasons that you mention” because the problem with modelling clouds is not that we don’t know how they’re formed. It’s s not the main problem anyway. The main problem is that high clouds increase the greenhouse effect — giving positive feedback for an increase in temperatures, while low clouds increase albedo — giving negative feedback. And while it’s obvious that increasing temperatures will produce more water vapour and more clouds, it’s very difficult to model what kind of clouds in what amounts will appear where, and to calculate the net feedback effect.

    J. Kirkby, et. al. […] has made other statements re cosmic rays & the formation of nucleates that “seed” clouds

    … and so far haven’t been able to support them with empirical evidence. As I said, saying something and proving something are two quite different things. Also, we are not really discussing the history of Kirkby’s claims, but the validity of “translating” this particular set od results as “cosmic rays cause clouds” — and this is still a gross misrepresentation of scientific research.

    Some would say, with compelling support, that when such speculation is predominantly based on ignorance, such models are “wrong.”

    Models are tested for stability in control runs, and validated against the instrumental temperature record. While by no means perfect, they actually do quite a good job. And anyway, they’re much better than the “simple models” of kinds that have been used and abused to “prove” that “climate models are wrong”. No contemporary GCM is “predominantly based on ignorance”.

    past decade’s nearly absent warming

    Puh-lease. You only see that when you cherry-pick your sample to start at an El-Nino crest and end at a La-Nina trough. Have a look at Figure 1 in this paper:

    http://pubs.giss.nasa.gov/abs/le02300a.html

    When you remove ENSO, volcanic and solar signal from the temperature record, you’re left with a steadily climbing linear component known as “global warming”. Do you see any “absence of warming” or “cooling” for the years 2000-2010? Me neither.

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