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  1. The figures showing a strong correlation between low cloudiness and GCRs was also the high-point of a television climate-denier polemic shown last night on Channel 4 here in the UK, entitled The Great Global Warming Swindle. Made [characterisation removed] Martin Durkin, whose previous anti-environmental film on genetic engineering got the broadcaster into trouble with television regulators (contributors had been edited to make their statements misleading, amongst other things – it had to make a prime-time on-air apology), it featured repeated contributions from all the usual deniers – Lindzen, Singer, Stott etc. There was no attempt at balance at all – only the climate-sceptic view was presented, and GCRs were the crux of the supposedly scientific attempt to show that CO2 is irrelevant in forcing climate change.

    Perhaps the weakest argument of all was the conspiracy theory – advanced particularly by Dick Lindzen – that pretty much all climate science nowadays is just chasing grants, and that the whole field is therefore distorted towards ‘alarmism’ by financial self-interest. That’s ironic, considering that the oil, coal and automotive industries, who one presumes have an interest in the climate denier case (hence all the well-established funding links) are hardly bit-players in the global political and economic scene…

    Comment by Mark Lynas — 9 Mar 2007 @ 4:45 AM

  2. Well, I don’t think you do any less “cherry-picking” than Lomborg, at least in the references you choose to attack or criticise. Much of this post is again selecting paragraphs and attacking them, straw-man style. Is this more about demonizing certain scientists and individuals than it is about venting frustration at their sloppiness and bias?

    [Response: Can you suggest any references that you think I should have included? E.g. on the trend in GCR, adjusting the ISCCP data, on how there is a shortage of aerosols/CCN?, on the observations of low clouds and high clouds, or on the role of ultra-small aerosols for cloud drop growth? -rasmus]

    Comment by Marco Parigi — 9 Mar 2007 @ 4:58 AM

  3. The irony is that Svensmark ignores (in addition to the lack of trend in GCR) the fact that the night-time temperature has risen faster than the day-time temperature

    I thought the SPM had concluded that new data, or new analysis of data, since the TAR had contradicted this result.

    The lack of trend in the GCR is a more fundamental problem, and it may well be that night time temperatures have risen faster than day-time temperatures, but I didn’t think we could say that with certainty at present.

    [Response:In the last few years, the diurnal temperature range (DTR) hasn’t changed, but it did diminish before then for a while. If we are talking about the warming since 1970s, then a reduction in the DTR would still matter for part of the period. -rasmus]

    Comment by Timothy — 9 Mar 2007 @ 5:28 AM

  4. Well done!. This was one of the main arguments used in a very biassed and scientifically inaccurate programme aired by Channel 4 (UK) last night. Indeed I found the political tone of the programme, especially linking the science of GW to being responsible for holding back economic development of the third world offensive.

    I am writing to the producer to complain.

    Nick Riley

    Comment by Nick Riley — 9 Mar 2007 @ 5:57 AM

  5. re 1 & 4

    The programme needs to be answered point-by-point by serious climate scientists. Why not approach Channel 4 for a right to reply?

    Complaints can be addressed here:

    The group Durkin was involved in have a long track record on issues like GM crops & even silicone implants, of supporting libertarian corporatism. They’re clearly not what the label on the tin says.

    Comment by Alex Nichols — 9 Mar 2007 @ 6:27 AM

  6. Re #5: The content of the programme was familiar to anyone who has dealt with the standard ‘contrarian’ websites. Calder & Svensmark have a new book coming out. William has discussed the programme here:
    There isn’t really any case to answer, as per…

    Comment by Fergus Brown — 9 Mar 2007 @ 6:59 AM

  7. Climate Change on Mars

    I believe that a newer angle on the Sun increased output is the fact that for 3 consecutive years now one of the poles ice caps has shrunk and that shows increased radiation outut by the Sun.

    Like to hear something on this one as I guess the CO2 atmosphere of Mars is unchanging so another forcing must be involved. Can it be natural variability ?

    [Response:See the post Global Warming on Mars? -rasmus]

    Comment by pete best — 9 Mar 2007 @ 7:05 AM

  8. This article from the UK (right wing bias broadsheet) Daily Telegraph newspaper seems to give it some credence especially as it has an experiment yet to be done tagged to it.

    Comment by pete best — 9 Mar 2007 @ 7:11 AM

  9. #3 Vose et al. 2005 thereafter (included as a robust feature in IPCC AR4 and SPM) do conclude that the most recent period 1979-2004 have an equal trend for Tmin and Tmax, so no trend in DTR. Interestingly the DTR decrease 1950-80 and null trend 1980-2004 fit well with a global dimming / brightening influence on recent temperatures. But there are surely other hypothesis.

    GEOPHYSICAL RESEARCH LETTERS, VOL. 32, L23822, doi:10.1029/2005GL024379, 2005
    Maximum and minimum temperature trends for the globe: An update through 2004
    Russell S. Vose, David R. Easterling, Byron Gleason

    Abstract – New data acquisitions are used to examine recent global trends in maximum temperature, minimum temperature, and the diurnal temperature range (DTR). On average, the analysis covers the equivalent of 71% of the total global land area, 17% more than in previous studies. Consistent with the IPCC Third Assessment Report, minimum temperature increased more rapidly than maximum temperature (0.204 vs. 0.141°C dec^-1) from 1950-2004, resulting in a significant DTR decrease (~0.066°C dec^-1). In contrast, there were comparable increases in minimum and maximum temperature (0.295 vs. 0.287°C dec^-1) from 1979-2004, muting recent DTR trends (~0.001°C dec^-1). Minimum and maximum temperature increased in almost all parts of the globe during both periods, whereas a widespread decrease in the DTR was only evident from 1950-1980.


    Rasmus, a typo : “paper paper” doubled in second paragraph.

    [Response:Thanks for pointing thius out – it’s now fixed. -rasmus]


    Concerning Svensmark cosmoclimatology, and if I try to summarize what I’ve understood, it seems the main points of debate are :
    – is there any trend in GCR for past 50 yrs / 100 yrs?

    [Response:No/not sufficient data (some anecdotal indication of trend during beginning of 20th century, though. ]

    – is there any correlation GCR/low cloud amount since 1980?

    [Response:This has been disputed]

    – is there any physical mechanism GCR/nucleation/CCN?

    [Response:There is probably some – see i.e. cloud chambers used to detect GCR, but my impression is that this is of secondary importance in nature.]

    – is there any influence of GCR on surface temperature 1850-2005?

    [Response:not sufficient data as GCR measurements started in the 1950s. ]

    – is there any influence of GCR on Tsurf on geological times?

    [Response:Now we are talking about uncertainties, both in the paleo-reconstructions of GCR and Tsurf . My impression is that since GCR affects the isotope ratio but Tsurf often affects different isotopes differently, the analysis easily gets tangled up (circular argument?). Perhaps someone can shed some more light on this?]

    Before “heating” the discussion with conflictual views or entering technical details, it would be nice to answer simply like “Yes there is for X, Y and Z, No there isn’t for A, B and C”, ABC and XYZ being peer-reviewed papers. Then, if we have contradictory views on a point, to go further in debate and try to evaluate which position seems more conclusive.

    As there have been many debates here on these points, such a clarifying and basic approach would be useful for lay readers. (For those who possess Rasmus book, part 7.10 pp. 179-191 is to be read)

    Comment by Charles Muller — 9 Mar 2007 @ 7:27 AM

  10. #1 – The first sentence of your argument started well, but turned into a rather boring ad hominem attack without any substance. Shame.

    #4 – Erm, I find the political tone of some of the AGW apologists (particularly the more vociferous ones) to be offensive. What makes me sad is the “pro-AGW” agenda receives 1000’s of times more television air-time than “anti-AGW” – and yet there IS good science going on on both “sides” of the debate.

    With regards to the article itself; there is some interesting stuff, but I find it a bit concerning that you can dismiss the GCR theory as a “last trench of the sceptics”, despite your own admitted surprise at the closeness of the GCR & temperature fit. I’d also be keen to know more about the sunspot activity vs. temperature, which according to Channel 4’s “The Great Global Warming Swindle” is also an excellent fit with temperature.

    You also state: “It is possible that GCRs do have an effect on climate through the modulation of clouds, but I don’t think it is very strong.” – on what basis do you think it is “not very strong”?

    Also, one final question: Are the Americans *really* spending US$4bn/year on climate research?

    [Response:I think we should be a bit careful here about accusing each others and too much personal views. It was my fault that the offending characterisations were passed through, but I have deleted that now. Let’s stick to the science or the issue of disseminating science. The link provided with the second last question here is to a paper which finds a statistically significant link between the diffuse light ad GCR, but the scatter of points between the two looks like a messy cloud rather than a well-defined line. Thus, a weak link. I don’t know how much Americans *really* spend on climate research. -rasmus]

    Comment by AdeV — 9 Mar 2007 @ 7:36 AM

  11. re 6. I wasn’t thinking of the blogosphere, I was thinking of the TV viewers who don’t, or can’t wade through the scientific arguments, but would have absorbed the tritely illustrated points which were made every 5 minutes before the commercial break.

    While the TV coverage of the issue has been quite balanced so far, there are always insidious attempts to undermine the basic science behind AGW.

    What I was thinking of was something of a more popular nature on TV which operated on a similar level to the Channel 4 prog. Failing that, a downloadable podcast.

    The internet is a powerful medium, but TV works on a different level.

    Comment by Alex Nichols — 9 Mar 2007 @ 7:49 AM

  12. On the GCR/low cloud issue:
    Kudos to uncle Eli and nexus 6 for first spot of this. Comments are on both their blogs.

    On the Cloud chamber experiment paper, I recall a statement something like; ‘the formation of CCNs as a result of ionisation is therefore shown to be possible in the absence of other cloud-forming nuclei..’

    Please excuse the paraphrase.


    Comment by Fergus Brown — 9 Mar 2007 @ 7:56 AM

  13. Of course, all of what follows is purely of ‘academic’ interest, given the stated lack of a trend in the GCRs with the climatology (and a generally adequate source of CCN); but, given

    … since higher clouds (global mean cover ~13%) or middle clouds (~20%) which are not influenced by GCR…

    Why is this supposed/true? Is this just down to a higher probability of an ionisation cascade effect much lower in the atmosphere than, say, in the stratosphere or top of the troposphere?

    [Response:If you view the clouds from above, as the satellites do, you will have problems seing the low clouds underneath high clouds where these overlap. Thus from a practical observational view, the obseervations of low clouds is not ideal.-rasmus]

    I’m not into cloud physics in any way, which is why I ask the question, but I’m was once well acquainted with supercooling and the need for heterogeneous nucleation in most things material.

    Might not GCRs, at least on initial inspection, be thought to have a greater effect at greater altitude? Given the lower temperatures and lower water vapour content at higher altitudes and a need for high supercooling to initiate condensation (in the absence of sufficient normal CCN), wouldn’t an increased source of nuclei, in the form of GCRs, enhance high- and middle-altitude cloud formation?

    [Response:True, the GCR, at least the primary particles, may be more aboundant at high altitudes, but if there are reactions where the GCRs produce showers of secondary particles through the collision, then this has implications for other altitudes too (eg see here). The higher up, the lower water content, and it is moisture which is most important for cloud formation. -rasmus]

    I know the auroras are well above any weather-producing region, but how low in the polar atmospheres could/do the ionisation cascades get that produce the auroras. If these ionisation cascades get to the ‘weather layer’, wouldn’t the poles be cloudier on average than expected, cf. at lower latitudes (and accounting for water vapour differences between the two extremes)?

    [Response:Auroras tend to be associated with solar particles trapped in Earth’s magnetic field, rather than GCR. both, however, are modulated by the solar activity. -rasmus]

    And with regard to Svensmark’s (“vague but false”) assertion about meteorologists and a lack of a mechanism, I can only presume that arises because all those meteorologists (presumably those that Svensmark was associated with/contacted on the matter — or does he mean all meteorologists?) only ever used one of those “whirly things” to gauge humidity. I don’t suppose they ever used a chilled-mirror dewpoint meter complete with 241-Am to nucleate said vapour to obviate supercooling to provide consistent results (IIRC). Ionisation on, instant (admittedly very small) ‘cloud’ formation.

    Comment by P. Lewis — 9 Mar 2007 @ 7:58 AM

  14. Great article about Mars, thanks for the link.

    From the Daily Telegraph article I deduce that scientists not totally immersed in the climate side of things possibly believe that svensmark has demonstrated enough interest that additional experiements are required to quantify the cloud formation forcing of GCR. Is it not possible to define experiments to resolve this one to a greater degree of accuracy. Would RC welcome more experiments or do you believe that the matter is settled?

    Comment by pete best — 9 Mar 2007 @ 8:01 AM

  15. I see the article has changed slightly since I penned my post, and “vague but false” is now “a counter-intuitive finding for some critics”. I don’t think this changes my perspective though, but would be happy for it to be edited if someone thinks it does..

    Comment by P. Lewis — 9 Mar 2007 @ 8:02 AM

  16. Huh! I hear people saying. All will become clear, I hope. A post is in abeyance!

    Comment by P. Lewis — 9 Mar 2007 @ 8:06 AM

  17. What are the sources of cosmic rays in the first place? Are there particular locations in the sky where they are stronger? Maybe from supernovae in other galaxies, or pulsars and nebulae closer by? If the distribution is not perfectly even, there ought to be a way to check the GCR effects by whether they affect the hemisphere that is never exposed to them (I know the Earth’s axial tilt reduces that area somewhat, but it’s still there). If the GCRs fail that test…

    Comment by Barton Paul Levenson — 9 Mar 2007 @ 8:07 AM

  18. Re #1. Just a clarification about describing Martin Durkin as a “Revolutionary Communist”. He is an associate of a number of people who were members of a weird little UK outfit called the Revolutionary Communist Party, which moved from a variety of Trotskyism to anti-environmentalist libertarianism with remarkable speed, then disbanded. I have not been able to discover whether Durkin was himself a member, although in the ’90s he described himself as a Marxist. Along its ideological trajectory the RCP’s magazine (initially “Living Marxism”, renamed “LM” – a surprisingly glossy publication for a party with a tiny membership and no other visible means of support) found time to deny that genocide took place in Rwanda, and accuse reporters for British television company ITV of faking footage of Bosnian Muslims in a Serb-run detention centre. LM’s publishers were sued for libel by ITV over this, and the magazine was forced to close. Ex RCP-ites now run “The Institute of Ideas”, “Sense about Science” and “Spiked Online”. The last of these hosted Lomborg’s visit to Britain, and has close links with the corporate-funded denialist organisation, the “International Policy Network”.

    Comment by Nick Gotts — 9 Mar 2007 @ 8:25 AM

  19. Re 16: Galactic cosmic rays are extremely high-energy ions (mostly protons) that impinge on us more or less isotropically from all directions. The peak in the GCR spectrum occurs at about 1 GeV per nucleon, although energies over 10^21 eV have been measured. It is thought that most GCRs attain their high energies by being accelerated by the high magnetic fields and shock waves from Supernovas. The fluxes of GCR are low–roughly 5 particles per square cm per second, and they are modulated by the 11 year solar cycle, with fewer GCR reaching the inner solar system during solar maximum (high solar wind) and more during solar minimum.
    Only moderately high-energy GCR make it through Earths Magnetic field without being deflected. Fewer still generate showers that make it into the Troposphere. GCR showers are responsible for most of the high neutron levels found in the upper atmosphere (>15000 meters).
    GCR showers also create lots of charged particles, and these charge tracks are thought to be the mechanism of cloud nucleation.

    OK, so here’s my question–we already know we get a big modulation in GCR flux between Solar Max and Solar Min. Has anyone looked to see if Solar Min years are notably cloudier than Solar Max years? That should be a pretty easy thing to do, and it ought to put the issue to bed unless I’m missing something?

    Comment by Ray Ladbury — 9 Mar 2007 @ 8:42 AM

  20. I have to say that this is mostly over my head, but I note that a recent Scientific American article on how cosmic rays might be the seeds for a cascade which results in lightning, and that without these rays, lightning might not happen was pretty cool.

    Comment by jhm — 9 Mar 2007 @ 9:13 AM

  21. Echo comment #19 about the issue being over my head. A very technical post.

    I understand the lack of correlation between GCR and temps since 1950, but then the significance of rasmus’s objections simply becomes opaque. I’m guessing that there are technical problems with Svensmark’s data and curiosities about the actual physical process of creating clouds. And possibly some historical questions about whether Svensmark’s laboratory described process actually has happened in the real world.

    Close enough?

    Comment by Jeffrey Davis — 9 Mar 2007 @ 9:29 AM

  22. #9 Thanks for answer, Rasmus. In the rest of the discussion, I’ll try to go back on some listed points still unclear for me.

    I’ve just finished Svensmark-Calder book, Chilling Stars. A New Theory of Climate Change, the popular version of cosmoclimatology. At first glance from what I’ve previously read about the topics, including on RC, I’d say it’s a seductive hypothesis, with fascinating links from terrestrial climate to galactic events, but that it’s still a weak hypothesis. On a purely rhetoric point of view, the authors too often jump from “GCR have an influence on climate” to “GCR are the main driver of climate on all timescales”. It would be more convincing for critical readers (I’m skeptic after all :D) to better demonstrate and quantify the first kind of assertions before drawing galactic perspectives on life destiny of the second kind.

    Anyway, I think the debate here must actually concentrate on scientific matter, and try to avoid injuring personal attacks.

    Comment by Charles Muller — 9 Mar 2007 @ 9:30 AM

  23. Hey All;

    Just a quick question, is it possible that there may be some relationship between ICME and GCR that could participate in high altitude barometric activity? (For instance, sufficient helium nuclei to add enough weight at the TOA to participate in a falling region which cooler air would flow to form a anti-cyclonic event.)

    [Response:No – William]

    The follow up is, is there a possible interrelationship between GCR and ICME events that can be established by correlation to barometric/Ross waves? Thanks for your consideration, I am curious as to US agency supporting data sets separate from the work done in the Netherlands recently.

    Dave Cooke

    Comment by ldavidcooke — 9 Mar 2007 @ 10:51 AM

  24. I know you’ve got to do it; it’s a big part of what RealClimate does. But given the talent and accomplishment of RealClimate posters, and the breathtaking developments in climate science lately (the dynamics of subglacial lakes, for instance), sometimes it strikes me as a little sad that you have to devote so much energy to refuting the utter twaddle emitted by denialist nincompoops, time and time again. Keep up the good fight, though!

    [Response: Personally, I find the problems of solar activity and climate really intriguing, especially put in the historical context. You can find thoughts about sunspots and climate variations dating back to the 17th century, so it’s one of the big classical problems. Over the centuries, one has tried to find a link between the two, and so it amuses me to see examine new claims of purported causes in details, and the history seems to be a good guide – the hypotheses keep toppling over once they are put in a critical light. On the other side, the GCR idea still has a few supporters in Scandinavia. Considering the new book and so on, it’s worth restating the obvious. Also, Svensmark & co say that it’s important to challenge the orthodox view, but it’s even more important to challenge new ideas. That’s how science works. -rasmus]

    Comment by Daniel C. Goodwin — 9 Mar 2007 @ 10:57 AM

  25. At one specific energy range, about a 4% difference in direction reported (from the center of our local galaxy, in the direction of the constellation Cygnus):

    I don’t know of any cloud data variability, don’t know how much the solar cycle variability is compared to this, and don’t know how many other energy ranges are being investigated.

    Found that while trying to look up the maximum energy for cosmic rays, and it’s apparently on the order of “enough to knock you down if it hits you” — a particle moving nearly at the speed of light has a huge mass.

    Comment by Hank Roberts — 9 Mar 2007 @ 11:08 AM

  26. #19
    I think the 11 yr modulation you mention is just a particular aspect of the general problem of GCR/cloud cover correlations. You can analyze this correlation day by day, year by year, cycle by cycle, etc.

    Evidences are not clear (but climatologies of clouds are poor, even for recent period).

    For example, except Svensmark et Friis-Christensen 1997, Marsh et Svensmark 2000, 2003 (and Laut 2003 critics on their methodology) :
    – Kristjansson et Kristiansen 2000 found no correlation on ISCCP / ERBE data, except for some marine midlatitudes (see also Kristjansson 2002, 2004).
    – Wagner 2001 found on Switzerland a correlation the period studied by HS (1980-1995), but not before
    – Udelhofen et Cess 2001 over USA 1900-87 found a phase correlation for solar cycles and cloud variations (rather than antiphase predicted by GCR hypothesis).
    – Sun et Bradley (2002) found for 1983-93 a weakened correlation limited to Atlantic Ocean, nothing elsewhere (including no 11 yr cycle signature), notably on tropical and extratropical lands.
    – Kristjannsson 2002 found on ISCCP data a better correlation of low clouds with TSI variations than with GCR.
    – Usoskin 2004 found a correct antiphase correlation with 11 yr cycles, but limited to some regions with low level of cloudiness.
    – Harrison et Stephenson 2006 over UK from 1947 found a small and non-linear effect of GCR on clouds (day-to-day, so also sensitive to minimum-to-maximum mean variations).

    I probably miss other studies. There are many factors affecting cloud formation at different latitudes and altitudes (including anthropic aerosol emissions), many difficulties for monitoring clouds at their different layers, and so many interrogations about statistical robustness for these correlations (or absence of). But Rasmus will correct if I’m wrong.

    Comment by Charles Muller — 9 Mar 2007 @ 11:59 AM

  27. I watched the Great Global Warming Swindle on Channel 4 last night, took notes and undertook an annotated deconstruction of all their arguments – and posted them here on our PhD blog.

    While I am not a climate scientist, I have an undergrad physics degree and I am a PhD researcher in climate policy. I have annotated the article with peer-reviewed sources as much as possible.

    I agree with a poster above, who worried about how the documentary attempted to appeal to emotion and fear about a global conspiracy. Equally damaging (if not more so) than the misinformation about climate they presented.

    Comment by Nathan Rive — 9 Mar 2007 @ 12:11 PM

  28. Re 24: The maximum energy seems to be about the same order of magnitude as a 100 mile per hour baseball! These are few and far between–only a few hit Earth per day. Interestingly, the argument goes that these should have to be produced fairly locally, since they are so high energy that they can interact with cosmic microwave background photons to produce an electron-positron pair. Yet at the highest energies, the flux is isotropic–implying extragalactic origin.
    Here’s a link to an interesting presentation:

    For climate purposes, the highest energies are irrelevant, as the flux is so low.

    Comment by Ray Ladbury — 9 Mar 2007 @ 12:16 PM

  29. >extragalactic origin
    Hmmm, I suppose if particles are constantly popping into existence and disappearing again from the background ‘quantum foam’ — there’s no reason they shouldn’t pop into existence moving at almost the speed of light, eh? And I recall that a photon, moving _at_ the speed of light, doesn’t experience time elapsing, so why should it be in any hurry to pop back out of existence once it’s arrived. Nah, too weird.

    Comment by Hank Roberts — 9 Mar 2007 @ 1:25 PM

  30. If you’re real honest scientists then program in the cloud nucleation, the cosmic particle flux, the flux modulation by Earth and solar magnetic fields, and the changes in the latter across the solar cycles, into your GCMs. And see what the models say, versus the historic record. That’s the MO of the real scientist.


    [Response: Since there is no trend in solar flux, why program one in? – William]

    Comment by M.Dinova — 9 Mar 2007 @ 2:05 PM

  31. > [Response: Since there is no trend in solar flux, why program one in? – William]

    Because it’s one of many processes that affect climate, and therefore part of the model that underpins climate science.

    Oh, and I notice that you deleted that part of my post that referred to the role of models in science, and how the honest scientist should behave with respect to the models and the scientific method. Less than honest of you.

    Comment by M.Dinova — 9 Mar 2007 @ 2:23 PM

  32. M. Dinova. So, how would you “program in” this effect? I mean since there is no clear trend (upward or downward) in cosmic ray flux over the period we’ve been able to measure them directly; and since we do not see a significant difference in climate over the 11 year solar cycle between Solar Max and Solar Min (and this modulation is much larger than the one Svensmark is talking about); and since it is not clear how important the ionization from GCR is in cloud formation; and since the anthropogenic ghg mechanism does just fine reproducing the data, exactly how do you foresee implementing this “effect”?
    What separates science from other forms of empirical enquiry is that it is guided by understanding–what effects are important and what effects are not. I have yet to see any compelling evidence that this effect even really exists, let alone that it could contribute to climate.

    Comment by Ray Ladbury — 9 Mar 2007 @ 2:41 PM

  33. Boy you guys are so right on . These are such tired arguments. Why can’t we all just agree global warming is man made and ignore the mountain of data that might question that assumption???

    Comment by tom — 9 Mar 2007 @ 2:47 PM

  34. Re 32: Gee, Tom. Must have missed that mountain. Given that it seems to be impossible to construct a climate model that even comes close to matching observed trends without an anthropogenic ghg mechanism, it’s hard to imagine where such a model could be hiding.

    Comment by Ray Ladbury — 9 Mar 2007 @ 2:54 PM

  35. Re: 31, M.Dinova
    I think you are missing the thrust of William’s argument. If there is no trend in GCRs, how can one incorporate the non-existant “changes” into GCMs? Creating an arbitrary trend in GCRs would just create an arbitrary result. Pretty much all existing GCMs take into account changes in cloud albedo effects (though these are still characterized by a fairly high level of uncertainty). Eventually, when we know more about the effects of the mechanisms involved, fluctuations in cosmic rays could be incorporated in helping model cloud albedo changes. However, the absence of a trend in GCRs corresponding with the recent increase in global surface temperatures suggests that GCR changes have a negligable effect on currently observed temperature changes that are (apparently correctly) ascribed to anthropogenic GHG emissions.

    Its not like solar flux is being ignored; far from it, as many of the realclimate authors have written about the effects of solar radiative changes on the earth’s climate in the peer reviewed literature. Galactic cosmic rays, however, still have a lot of details to define before they can be incorporated into any sort of predictive models. Svensmark has done some pioneering and interesting work that has led to suggestions that GCRs can, at least in theory, play some role in cloud formation. His error, however, is in suggesting that this discovery (with limited understanding of its magnitude) somehow throws into doubt existing models of AGW (which are based on much more firmly established physical processes with trends in different climate forcings that are directly testable against the historical temperature record).

    Comment by Zeke Hausfather — 9 Mar 2007 @ 3:19 PM

  36. re: #19.

    “agree with a poster above, who worried about how the documentary attempted to appeal to emotion and fear about a global conspiracy. Equally damaging (if not more so) than the misinformation about climate they presented. ”

    Sounds like the flip side version of Inconveneient Truth. Would you agree with that assessment?


    Comment by tom — 9 Mar 2007 @ 4:13 PM

  37. What really concerns me about all this is that the backlash that’s bound to come will affect all of science indiscriminately, not just the bad scientists who are willfully disregarding processes that don’t suit them, but also those good scientists who don’t endorse any particular view but let the scientific method decide.

    After this utterly non-scientific debacle is over, we’re all going to suffer.

    Science is not about advocacy nor partisanship to a *belief*. It has nothing to do with what you personally feel is correct or incorrect, and it certainly has nothing to do with bashing other scientists’ views.

    Put the theories into your models for every last natural process that could possibly have an effect, and do the usual hypothesis testing that you all know very well is the bedrock of science. Nothing else matters.

    [Response:I tend to concur. But to try to find out which hypothesis is wrong and which is right, both the old and new views have to be challenged. Svensmark has challenged the established view, and I have challenged his (because I’m not convinced by his arguements). -rasmus]

    Comment by M.Dinova — 9 Mar 2007 @ 4:46 PM

  38. #34 .To say there is not a subsantial amount of data out there which challenges the assertion that global warming is significantly caused by humans is massively disengenous at best.

    Comment by tom — 9 Mar 2007 @ 4:47 PM

  39. Re #31: [Because it’s one of many processes that affect climate, and therefore part of the model that underpins climate science.]

    Assuming that changes in the flux of GCRs do affect weather and/or climate – and as far as I can tell, there’s little if any evidence that it does – you still have the problem of explaining why & how changes in the flux can have affected the climate for the last 50 years or so when the flux hasn’t changed in that period. So if you’re doing an honest job of programming it into a climate model, all that happens is that you change things by some small constant factor.

    Unfortunately, it seems that just about everyone pushing this GCR notion is working backwards. You all start with the marvelous notion that GCRs (or whatever your alternative theory du jour happens to be) is exactly sufficient to explain observed changes, which – and this is the point of the exercise – allows you to disclaim responsibility for dealing with climate change. You then reverse-engineer your theory, without offering any intermediate evidence, so that the cause you postulate gives exactly the effects you want.

    Sorry, guys, but that’s not science, it’s just wishful thinking, :-)

    Comment by James — 9 Mar 2007 @ 4:48 PM

  40. Re: #36

    To say there is not a subsantial amount of data out there which challenges the assertion that global warming is significantly caused by humans is massively disengenous at best.

    We’ve looked at the evidence. We haven’t avoided it or waved it away. It has been weighed, it has been measured, and it has been found wanting. It’s not disingenuous; it’s just honest.

    Re: A question

    For those who do GCMs: has anyone played with putting in artificially high (or even realistic) solar variations or albedo variations with a solar-cycle (11-yr) period, to gauge the climate sensitivity to high-frequency (11-yr period) forcings?

    Comment by tamino — 9 Mar 2007 @ 5:02 PM

  41. “I think ‘cosmoclimatology’ is a good and refreshing name for anything combining our cosmos with our climate.”

    As it is international heliophysical year,Would not it be more proper to use the UN designation of heliophysics.

    Then interested participants would discover a substantial scientifc community dedictated to plasmaphysics and high energy mechanisms as described by Nasa as THE NEW SCIENCE OF THE SUN-SOLAR SYSTEM CONNECTION

    “Heliophysics concentrates on the Sun and its effects on Earth, the other planets of the solar system, and the changing conditions in space. Heliophysics studies the magnetosphere, ionosphere, thermosphere, mesosphere, and upper atmosphere of the Earth and other planets. Heliophysics combines the science of the Sun, corona, heliosphere and geospace. Heliophysics encompasses cosmic rays and particle acceleration, space weather and radiation, dust and magnetic reconnection, solar activity and stellar cycles, aeronomy and space plasmas, magnetic fields and global change, and the interactions of the solar system with our galaxy.”

    The IHY has an intersting monologue on the differences of the understanding of influences of coupling in the science of Aeronomy..

    “Atmospheric scientists tend to divide the gaseous regions above a planet into two broad categories called simply lower and upper atmosphere. For Earth, the study of the lower regions (troposphere and strato-sphere) form the discipline of meteorology. The study of the upper regions (mesosphere, thermosphere, exosphere) and their ionized components (the ionosphere) form the discipline of aeronomy. The negative aspect of such a two-fold division is that it encourages thinking of the various atmospheric-spheres as isolated regions of self-contained physics, chemistry, and (in the case of Earth) biology. In reality, there is consider-able coupling from lower to upper regions, an aspect of aeronomy fully appreciated only in the last decade. Com-plimenting this external influence from below, an upper atmosphere has long been known to experience forcing and coupling to and from regions far above it. Aeronomy thus deals with one of the most highly coupled systems in space science — with neutrals, plasmas, and electromagnetic processes that link the planets, moon, and comets from their surfaces to the solar wind and ultimately to the Sun itself.”

    With about 250 papers and 15 reviews to be published this year up to the substantive multidisciplinary publications from the combined Russian and CIS academies of science in October I would expect to see enhanced assimilation of various radiative stochastic fluctuations with their various mechanisms of amplification and attenuation as causal agents in specifc phenomena.

    Comment by makarov — 9 Mar 2007 @ 6:36 PM

  42. Concerning all the arguments above on the theme “you need first to have a clear signal of GCR effect on past 20, 50, 100, etc. yrs”, I think it’s not really conclusive. Fourier or Arrhenius were OK and true scientific pioneers about CO2 greenhouse effect without any model for detecting and attributing a CO2 signal in 18th or 19th century temperature.

    Comment by Charles Muller — 9 Mar 2007 @ 7:51 PM

  43. Notice how many contrarians chime in with “Wait, I found a different forcing factor, the area of my research focus, which accounts for all the recent variation better than all your previous ideas. So, relax, CO2 is not a greenhouse gas after all; the climate sensitivity to CO2 must be zero” (though they never say it this clearly.) This howling non-sequitur just keeps popping up like a game of whack-a-mole: Abdusamatov for solar variation, Svensmark & co. for GCRs, and so on.

    The skeptics (used to?) try to argue we don’t have a clear signal of recent warming, that the data is too uncertain, 1998 ended the trend, blah blah. Yet they turn around and find absolute certainty that they’ve found a long-term trend in solar irradiance, where our direct measurements span only a couple of decades, barely more than two full 11-year cycles, and we’re up against serious challenges on inter-satellite calibration. But they’re eager to wave away those doubts and declare the trend is known with certainty, and is big enough to sweep away all other forcings.

    Given that we have even less direct measurement of GCR levels or trends, this same irony is doubly applicable. How good a proxy do we have for century-scale GCRs, anyway? But the contrarians are a lot more willing to follow any proxy that leads away from GHGs.

    Comment by Jim Prall — 9 Mar 2007 @ 9:34 PM

  44. How much does the US spend on climate research? I had to look a bit but I found the CCRI – Climate Change Research Initiative, under the CCSP – Climate Change Science Program. The funding for CCSP in 2004 was nearly $2 billion, with $237 million of that slated for CCRI:
    I think much of the rest must be for earth observation (fed through NASA) though I haven’t found the numbers.

    The higher figures of $4 billion might have come from including R&D funding for renewables and hydrogen and/or subsidies for adoption of cleaner options (relevant for climate but not research on climate).

    The funding leveled off or fell for FY06, according to

    A current US .gov page on these programs’ budget is:

    It lists FY06 request for CCRI at $172 million, CCSP at $1 billion. Another $880 million goes to NASA for space-based observations.

    On the nav bar of that page I found a link to a history of these programs’ funding since 1985:
    CCSP funding in real terms peaked in 2004 and has dropped significantly each year since.

    Comment by Jim Prall — 9 Mar 2007 @ 10:28 PM

  45. Now I’m fixated on finding out what the US spends on climate modeling (the skeptics make it sound like quite a gravy train.) The key point to tease out is that those budget figures with a B for Billion cover the entire science process, with the lion’s share of the money going to data collection – paying for high-precision instruments to go on satellites, the cost of the launches, ground station operation to track and capture the data, miles of backup tapes for the petabytes of raw data…

    The bodies that actually do the modeling get some number of millions with an M. According to the 2007 budget (request?) for NCAR is $85.7 million. At it shows NCAR covers several projects: CISL for modeling, but also EOL and ESSL which do lab and field science ($$$) So let’s guess CISL gets 1/3 of $86M or $29M. This year they’ve installed a 12 teraflop supercomputing cluster named Blueice with 4 TB of RAM and 150 TB of disk. I imagine that’s spread over a few years’ budget…

    IBM did not release the price for Blueice:
    That article mentions that NCAR staff number 1200 scientists and researchers. They are getting by on $86M, or $71,670 per researcher. Most of that has to be going to salaries, benefits and overhead, with at most 10-15K per researcher for all that leading edge supercomputing. Given the prominence of their work, it’s notably cost effective. Of course I’m piecing all this together by guesswork, and their budget may be more complex (e.g. separate capital funds for supercomputers? Surely the remote earth observation must fall largely under NASA’s budget with NCAR just paying for the data capture end? All guesses!)

    Anyway, a bit of a different picture than the skeptics’ putative Billion-dollar modeling gravy train.

    Comment by Jim Prall — 9 Mar 2007 @ 11:36 PM

  46. Solar Forcing of Climate. 1: Solar Variability
    Space Science Reviews 120 (3-4), 197 (2005)

    …”We describe the variations with time of the solar irradiance and of the flux of ejected magnetised plasma. We discuss the probable cause of solar variability. Planetary influences are ruled out; the variability is intrinsic and is described by the solar dynamo. The dynamo is characterised by internal toroidal and more superficial poloidal fields, interchanging and alternating in a 22-year periodicity. From these two components in the solar magnetic fields emanate two possible scenarios for the Sun-climate interaction.”…

    …”The variable part of the solar radiation flux is mainly emitted by the chromospheric parts of the CAs. That radiation component does not reach the Earth’s troposphere since it is absorbed in the higher, stratospheric terrestrial layers. Tropospheric solar-driven variations should therefore be due to stratosphereâ??troposphere coupling. The Group Sunspot number R Gs is a proxy for the variable irradiance component and for the toroidal field variations.”…

    …”Thus, by emitting magnetised plasma, the Sun influences the Earth’s atmosphere indirectly, by heliospheric modulation of the component of the galactic cosmic radiation (CR) that reaches tropospheric levels. Modulation is only important for cosmic ray particles with energies below about 50 GeV. Cosmic ray ionisation plays a minor role at ground level but it is the predominant ionising agent in higher atmospheric layers, already above a few kilometres. The amplitudes of the CR variations depend on those of the solar cycle. The atmospheric rate of ionisation varies with CR-intensity. A current hypothesis is that the variable ionisation may affect the degree of cloudiness. Cosmogenic radionuclides such as 10Be are proxies for this influence and for the poloidal field variations.
    The R G and cosmogenic radionuclide proxies, although loosely correlated, refer to the two different aspects of the solar dynamo with their different terrestrial effects; they do not reach maximum intensity simultaneously and should therefore neither be confused nor be interchanged. Cases have occurred in which the one varied strongly while the other did hardly or not at all. The explanation must be intrinsic in dynamo theory.

    …”There is a significant solar signal in the troposphere; it depends on latitude and longitude. A physical investigation of the cause of the Sun-climate relationship based on one unique Î?T(time)-curve, assumed valid for the whole Earth’s surface, is therefore basically incorrect. Never during the past 10,000 years has the Sun been as active in ejecting magnetised plasma as during the past few decades. Estimates suggest that the level of solar activity may recently have passed its maximum and that it may decrease in coming decades.”…

    …”â??The future of such a chaotic system is intrinsically unpredictableâ??.

    Comment by BarbieDoll Moment — 10 Mar 2007 @ 1:49 AM

  47. WRT 37 and the reply, it is not that Svensmark and Co have a new hypothesis, it is not new, I have found one such proposal from the mid 70s , Shaviv has a link back to Edward Ney making a similar proposal in 1959, and if you go looking on sci.environment there is a ton of stuff about similar claims from the early 90s.

    The idea is obvious, but keeps getting proposed because those who propose it are pretty clueless about climate and get sucked in by correlations in tricky data. There is also some reasonable suspicion is that on occasion they have, ahem, massaged the data in tricky ways. For example, the 1990 papers by Friis-Christensen and Lassen after tearing up the town were sent to a watery grave when it was shown that the supposed cosmic ray signal was El Nino.

    The recent Svensmark paper on forming clusters is another case. The assumption was that the limiting factor was the formation of nanosized clusters, but the folks who study CCNs know that there are more than enough nanosized little things in the air from dust, etc, that a few more don’t matter. The whole thing puts me in the mind of cold fusion. A few die hard advocates, with political cover, pushing their peanut up the hill.

    Comment by Eli Rabett — 10 Mar 2007 @ 1:56 AM

  48. WRT 37 and the reply, it is not that Svensmark and Co have a new hypothesis, it is not new, I have found one such proposal from the mid 70s , Shaviv has a link back to Edward Ney making a similar proposal in 1959, and if you go looking on sci.environment there is a ton of stuff about similar claims from the early 90s.

    The idea is obvious, but keeps getting proposed because those who propose it are pretty clueless about climate and get sucked in by correlations in tricky data. There is also some reasonable suspicion is that on occasion they have, ahem, massaged the data in tricky ways. Another example, the 1990 papers by Friis-Christensen and Lassen after tearing up the town were sent to a watery grave when Paul Farrar showed that the supposed cosmic ray signal was El Nino.

    The recent Svensmark paper on forming clusters is another case. The assumption was that the limiting factor was the formation of nanosized clusters, but the folks who study CCNs know that there are more than enough nanosized little things in the air from dust, etc, that a few more don’t matter. The whole thing puts me in the mind of cold fusion. A few die hard advocates, with political cover, pushing their peanut up the hill.

    Comment by Eli Rabett — 10 Mar 2007 @ 2:07 AM

  49. Henrik Svensmark (2007)
    Cosmoclimatology: a new theory emerges
    Astronomy & Geophysics 48 (1), 1.18â??1.24.

    …”By 2005 we had found a causal mechanism by which cosmic rays can facilitate the production of clouds (Svensmark et al. 2007). The data revealed that electrons released in the air by cosmic rays act as catalysts. They significantly accelerate the formation of stable, ultra-small clusters of sulphuric acid and water molecules which are building blocks for the cloud condensation nuclei.”…

    Incidentally I did not see in the paper and within their hypothesis an exclusion of lightning (ground or top based) in conjunction with their proffered explanation of an electron charge induced cloud nuclei. And or all other possible explanations for the origins/sources of said electrons said to induce such an effect. Additionally, it’s two entirely separate issues, when you break it down, to even sort the matter out.

    Origins/sources of nuclei inducing material is one issue and another is the causual explanation/evidence of how those sources/origins would form mechanisms that would produce nuclei, and, in turn how those nuclei produce clouds rather than something else.

    Then the paper further takes on climate change and other issues (ideas about ideas).

    Seems to me there are many steps missing just in relation to one issue, let alone
    multiple topics and issues.

    It’s a paper that is written with great assurance but where is the true scientific process methodologies (for example: ruling out all other sources/causes/explanations) to back their conclusions/beliefs, rather than speculations and assumptions offered regarding their ideas on the matter?

    This is another in the line of mass produced hypothesis generating papers we see rather than a hypothesis confirming or supporting paper. But sadly, it appears impressive, I would imagine
    to the average joe public, because of the assuredness and authority of the authors presentation of
    the matter.

    Lightning’s Shocking Secrets
    SANDRA BLAKESLEE (July 18, 2000)

    …”Their eight-week experiment, called the Severe Thunderstorm Electrification and Precipitation Study, or Steps, ended on Sunday. Scientists say that the experiment turned up some stunning surprises that may force them to revise their theories of how lightning is produced.”…

    ..”Preliminary data show that charge fields — the layers of positively and negatively charged particles within clouds — do not fall into the conventional pattern, Dr. Krehbiel said. They are often upside down, meaning negative on top and positive below. “…”In a positive-to-ground lightning strike, positive charges first rush from the cloud to the ground, creating a lightning channel through which electrons flow from the ground back up to the cloud. Such lightning strikes tend to carry more charge, last tens of seconds longer and be less branched than the more common negative-to-ground lightning. But how this reversal of charge occurs remains something of a mystery, Dr. Rust said.”…””Storms may reverse their polarity all the time, but we just never knew it,” Dr. Krehbiel said.”…”Somehow, he explained, lightning discharges in the lower atmosphere are having effects in the upper atmosphere. “…

    [Response:I left out the notion of lightening because the post was already getting quite long and because I think we do not know much about the relationship between lightenig, climate, and solar activity. Dr. Krehbiel was my supervisor for one year before I gave up lightening and thunder because I felt it was a difficult topic in which it was difficult to make good observations. He is an excellent scientist, though. -rasmus]

    Comment by BarbieDoll Moment — 10 Mar 2007 @ 2:49 AM

  50. If rasmus really thinks that Svensmark rides a dead horse, is the ongoing CLOUD experiment at CERN (which probably will be ready in 2010) a superfluous spending of fundings?. See here for the link to the CLOUD documents.

    Comment by Francis Massen — 10 Mar 2007 @ 7:55 AM

  51. [[Boy you guys are so right on . These are such tired arguments. Why can’t we all just agree global warming is man made and ignore the mountain of data that might question that assumption??? ]]

    How about because the data does not, in fact, question that assumption? Or that it’s not an assumption, but a conclusion from the data?

    Comment by Barton Paul Levenson — 10 Mar 2007 @ 9:28 AM

  52. 50 Yes. If for no other reason that we already know that cosmic rays caus ions, and molecules cluster about them. The key issue is what happens in the natural atmosphere that controls the number of water drops that form from the nanosized cluster, and how they grow and evaporate.

    Comment by Eli Rabett — 10 Mar 2007 @ 10:02 AM

  53. [[Concerning all the arguments above on the theme “you need first to have a clear signal of GCR effect on past 20, 50, 100, etc. yrs”, I think it’s not really conclusive. Fourier or Arrhenius were OK and true scientific pioneers about CO2 greenhouse effect without any model for detecting and attributing a CO2 signal in 18th or 19th century temperature. ]]

    You may be confusing the greenhouse effect here with global warming. Fourier spoke of the former, Arrhenius of the latter. Arrhenius’s inspiration was the discussion then current of the cause of the ice ages.

    Comment by Barton Paul Levenson — 10 Mar 2007 @ 10:41 AM

  54. I am reminded of the school science fair project which expounded upon the dangers of “di-hydrogen monoxide”. A high percentage of the viewers of the exhibit actually wrote to congress asking that the dangerous chemical di-hydrogen monoxide be banned.
    I tried to tell somebody about the space elevator the other day. He asked if it would reach all the way to Mars.
    The point is that the average person is far too stupid to understand any of this and half the population is even stupider. How do we solve THAT problem?

    Comment by Edward Greisch — 10 Mar 2007 @ 11:14 PM

  55. RE: 54

    …”The point is that the average person is far too stupid to understand any of this and half the population is even stupider. How do we solve THAT problem?”

    Good luck there.

    Consider that a huge number of people are actually illiterate, lucky to read at a vague 8th grade level, or functionally illiterate in the compounded step by step functions required in directions, along with a direct lack of reading comprehension cognitive processes and one just sighs.

    Illiteracy In America
    By Timothy N. Stelly, Sr.
    (Aug. 22, 2005)

    Incidentally, I listened to a TV program the other night that featured Brian Ross investigating the African email money swindling scams. Lo and behold there were plenty
    of physicians and attorneys being snared by it.

    Which did not surprise me, to be truthful, as I have worked with both, but its still a poor reflection of our so called higher learners and another sad example of the state of nation.

    The one thing that does seem to have become in favor of observationally acknowledging climate changes outside of the expected norm, without being scientifically titled or of greater intellectual capacity, would be that some of the manifestations or effects, regardless of attributional cause, are becoming more day to day tangible and visible in comparison to the expected past climates that the public has enjoyed.

    You know, sometimes, at the end of day when it comes to relating to the average person it goes back to their embrace of such folksy things as:
    when there are going to be heavy rains or floods, the ants will build their hills higher.

    Such is life that one works with what one is given and we need to be even MORE understanding of others in relation to talking over their heads or with enclycopedia mouths.

    Guilty here myself of using an encyclopedia mouth to the extent people don’t understand me. So, one goes with the flow and adapts at their level, rather than expecting them to have to adapt to our levels. It’s easier anyhow than explaining every darn thing you equated in a conversation.

    And I would imagine many people who lack the understanding of the climate sciences are grateful for this site and the patience of the scientists who spend their time trying to elaborate on the science of the topics, or their efforts to clarify and make simple many hard to fathom nuances; not to mention their analysis and discussions of the recent papers released in the field.

    Comment by BarbieDoll Moment — 11 Mar 2007 @ 1:56 AM

  56. [edit]

    I think GCR should not be considered a “dead horse” but a hypothesis that deserves consideration. The IPCC says man-made forcings are very likely 90% of total forcings, with ‘very likely’ being 90 to 95% probable. If I do the math right, there’s between a 1 to 10% chance then that nature is responsible after all. Before the world “acts now” to stop GW, which will cost lots of money (e.g. sequestering carbon costs up to 30% of the input energy to perform, says an IPCC report), we should study the problem more, don’t you think? While carbon in the atmosphere may indeed stay there for 100s of years, I don’t think even another 100 years of unmitigated anthropogenic CO2 pollution will be fatal to the planet. In short, look before you leap, and let’s keep politics out of this.

    Ray Lopez


    It is possible that GCRs do have an effect on climate through the modulation of clouds, but I don’t think it is very strong. I also think that Svensmark’s claims are wildly exaggerated, but most of my objection lies in the way the arguments have been presented in this A&G articl

    If rasmus really thinks that Svensmark rides a dead horse, is the ongoing CLOUD experiment at CERN (which probably will be ready in 2010) a superfluous spending of fundings?. See here for the link to the CLOUD documents. [] Comment by Francis Massen � 10 Mar 2007 @ 7:55 am

    Comment by Ray Lopez — 11 Mar 2007 @ 5:47 AM

  57. This issue reveals once again the primary importance of understanding how clouds behave, and how aerosols behave, and how the two interact with one another. Lindzen’s IRIS hypothesis was another example of relying on a theoretical picture of how clouds behave, but the actual data from CERES showed that those assumptions were unjustified:

    “For example, a group of scientists recently proposed an idea called the “iris hypothesis.” They suggested that the canopy of clouds over the tropical Pacific Ocean recedes when the water’s surface temperature increases. Fewer clouds would open a window through which heat could escape to space and thus cool the planet. Earth, they argued, has a natural response that counteracts rising temperatures — a bit like an iris in a human eye dilating to adapt to low light.

    But does Earth really respond that way?

    Wielicki and other NASA scientists used CERES to test the idea. It turned out that such clouds did trap infrared heat. But even more so they reflected visible sunlight back into space. Fewer of the clouds would mean more global warming, not less.”

    Similarly, aerosols don’t automatically become cloud-condensation nuclei, as demonstrates.

    However, when we look at the overall claim made by the global warming denialists, it really is ridiculous – they claim that galactic cosmic rays influence the climate through some very hypothetical and convoluted process involving the solar and earth magnetic fields, formation of aerosols, and formation of clouds (the right sort of clouds, that is…), and then they also claim that CO2, CH4 and N2O do not influence the surface temperature despite all the theoretical and experimental evidence that they do.

    This demonstrates how the scientific discourse about all the different factors involved in climate has been misused and abused by a handful of scientists and political advocacy groups when it comes to discussing these issues with the general public. The fact is that infrared-absorbing gases act like an atmospheric blanket that slowly raises the surface temperature; this leads to more water evaporation, and water vapor is also an infrared-absorbing gas, which also acts as a blanket, so the surface warms more; as the poles begin to melt there is less snow, so the ground absorbs more radiation; over the past few million years the orbital solar forcing has caused the system to osciallate back and forth; there are many factors that are poorly understood (for example, if biosphere respiration > photosynthesis, atmospheric CO2 levels rise; if photosynthesis>respiration, CO2 levels fall; is this involved in glacial cycles?) – but the fact is that we’ve altered the system by injecting gigatons of ancient fossil fuel carbon into the atmosphere, in the form of carbon dioxide and methane – and to get back to cosmic rays, we know this is so because cosmic rays produce radioactive carbon-14 in the upper atmosphere, which has a halflife of around 6000 years, meaning that ancient fossil fuels have no C14 in them, meaning that we can determine the sources of atmospheric CO2 by measuring its C14 content.

    Comment by Ike Solem — 11 Mar 2007 @ 12:38 PM

  58. Re #56: [The IPCC says man-made forcings are very likely 90% of total forcings, with ‘very likely’ being 90 to 95% probable. If I do the math right, there’s between a 1 to 10% chance then that nature is responsible after all.]

    I think what you have there is in fact the chance that changes observed up to now are the result of natural changes, and not past human activity. It’s not saying anything about what future changes may accumulate.

    [Before the world “acts now” to stop GW, which will cost lots of money (e.g. sequestering carbon costs up to 30% of the input energy to perform, says an IPCC report)…]

    If carbon sequestration was the only option, you might have an argument. As it it, it’s only an argument against using fossil fuels for power generation. There are other options, ranging from conservation (does the world really, really need to illuminate thousands of square miles of empty parking lots, for instance?) to increasing efficiency to using other energy sources. Many of them actually save money in the long run.

    Comment by James — 11 Mar 2007 @ 3:42 PM

  59. Just some comments re. the Ch4 programme and its aftermath, and then a technical question/suggestion.

    Although not a climate scientist myself, I was appalled by the Ch4 programme. I forced myself to watch it, however, as I think that all scientists have to be aware of how (essentially) the big scientific stories are being presented, so that we can deal with the questions we get from our students/friends/family/thewider public etc. Indeed, only yesterday, my brother gave me quite a grilling about the programme and why we should be concerned about climate warming at all, although he did admit afterwards that he was very much playing “devil’s advocate”. It’s good practice to be able to respond to this sort of direct and assertive questioning, but probably only if the interlocutor is genuinely interested in the answer. However, I am not sure how interested in alternative opinions were some/all of the contrarians who were interviewed on the programme! What’s even worse, though, is the effect the programme has had on the wider public. I listened to the phone-in on BBC Radio 5 live the following morning, and I would judge that 70-80% of the respondents thought Ch4 had done a really good job, debunking myths put about by a lot of biased, grant-chasing scientists. Hardly anyone spoke clearly or resolutely in favour of the attempts by the climate science community to come to an informed and well presented view. The general skepticism I heard from the public, and their support for the Ch4 programme, left me even more depressed than the programme itself! However, we just have to persevere. Perhaps, via Realclimate, we could demand a right of reply?

    On a technical note, in my own research (I am an geomorphologist, main interests in modelling landscape evolution over the Quaternary, and also in clarifying equifinality and equifinal behaviour of spatially/temporally discretised models, which are all semi-empirical to some extent), I have been developing and using ‘metamodels’ to explore high dimensional factor spaces of large inherent uncertainty. The outputs from such metamodels can be used to forecast, with error (via a bootstrap or similar technique), a wide range of scenarios, which would be completely infeasible if using full simulations. Are these techniques being used in the climate sciences to any extent? I am aware of only one recent report in this respect, by Peter Challenor (Technical report for the Tyndall Centre, no. 45 or after, I think – it’s on the web) but no others. It’s a very powerful technique, which I am happy to discuss with people, and which I would strongly recommend as a model exploratory tool.


    Nick Odoni
    School of Geography, Southampton

    Comment by Nick Odoni — 12 Mar 2007 @ 3:02 PM

  60. A Pragmatic Theory to Explore:

    I find the comments and explanations in this site interesting and compelling, and at times very difficult to understand. I must also admit that the level of complexity for which your examinations attain are a true signal of the quality to found with, and as I have come to agree with, the theory that climate change is linked to human creation of greenhouse gases, or more broadly termed pollution. It is with the word ‘pollution’ that I find the second most compelling case for reducing Co2 and other chemical or greenhouse elements. Even if we are wrong about the causes of climate change, surely severely reducing the pollutants we pump into the localised and global atmosphere (I will go at this stage go into the importance of stopping deforestation) is an incredibly positive achievement for which our children would be incredibly proud. The technology and intelligence to maintain a high level of life style is at hand but we seem unable to invest the required intellectual and economical capital. While huge amounts of the afore mentioned capital finds its way into other less productive human endeavours such as the war in Iraq (est at $1.8 billion a week, figures found at –

    So while some may still favour the 10% probability (IPCC recent data) that humans and Co2/greenhouse emissions are not causing climate change, surely to err on the side of caution and at the same time create an enhanced living environment, and then start to think about the truly important battle of sustainability and conservation, would be the most intelligent and responsible strategic plan.

    I look forward to any comments regarding this theory…

    William Laitinen

    Comment by William Laitinen — 12 Mar 2007 @ 8:46 PM

  61. re. No trend in solar proxies since the fifties

    I don’t think there needs to be a trend in a forcing parameter of a system over a given period in order for that parameter to be driving a noticable change in that system during that period.

    An example would be to take sunspot number as a proxy of solar activity – no trend since the 1950s – and assume that the global mean annual temperature anomaly is driven by the sunspot number according to:

    This year’s anomaly = last year’s anomaly + (sunspot number – 40)*0.0003

    Under this relationship the global mean temperature would have carried on increasing strongly since the fifties even though there is no real trend in sunspot number over that period. Note – I’m not saying I think this formula is correct, even if it does do a pretty good job of following the measured temperature anomaly! Just wanted to point out that ‘no trend’ does not equal ‘no change.’ Just for fun you can see the graph of the above formula for sunspot based temperature anomaly prediction at

    Comment by Geoff Loveman — 13 Mar 2007 @ 7:27 PM

  62. I have followed the GCR-climate debate over the past year or so, via scientific journals as well as via several internet platforms including realclimate. I have a few questions that I could not find the answer to.

    The CLIMAX Neutron monitor does not show any trend in GCR since the 50s. However, cosmic ray proponent Shaviv claims that the ion chamber data are more relevant for potential aerosol (and the “hopefully” cloud) formation, because of the energies measured. And he claims that they do show a decreasing trend.
    I have read here on RC that the two (or multiple) types of particles should agree with each other, and that neither side of the argument has an explanation for the fact that they do not. Now it’s easy to say that each side just picks the data that suits their hypothesis, so my question is: Why would the CLIMAX neutron monitor be the better data series to look at? Do they cover a longer time period? Are they regarded as the “reference” measurement? But would such reasons deem the trend in the ion chamber data statisticlly insignificant? Or are the ionchamber data Shaviv refers to rubbish to begin with?

    My second question is more general: Climate sensitivity is bounded by how well we can model the 20 century temperature increase with the known forcings, and by the last ice age, right? So if (and I know that it’s a very big if) there is another forcing that up till now was not included in the 20th century modeling excercises, the climate sensitivity according to the first line of thinking would be lower (as per the Nature paper of Andreae et al (2006)). How strong is the constraint on climate sensitivity by inspecting the last ice age versus the constraints that stem from modeling the 20th century temperature increase? I.e. would such an unaccounted forcing (or alternatively, a much larger aerosol forcing than currently thought) indeed force the climate sensitivity to be revisited or not, and if so, to what extent? If they don’t agree, would we take the average of the two as the most likely number? It’s nice that currently the climate sensitivity you get from both lines of evidence more or less agree, and it indeed strengthens the claim that it’s probably not far from the truth, but I think the “what if” question is important in countering common sceptics talk.

    Thanks for the great site!

    Comment by Darrel — 14 Mar 2007 @ 7:57 AM

  63. Why would the GCR count have been lower for the early Earth? If Svensmark is dependent on Solar activity to mediate GCR flux, wasn’t the Sun 25% dimmer than now at 4.5 GYA? Which would mean less modulation, which presumably would result in a GCR flux with less Solar interference. Am I missing something?

    Comment by Barton Paul Levenson — 14 Mar 2007 @ 9:46 AM

  64. …”Its not like solar flux is being ignored; far from it, as many of the realclimate authors have written about the effects of solar radiative changes on the earth’s climate in the peer reviewed literature.”…

    Very true, and yet there are methodology conflicts and uncertainties still to be clarified and determined. However, it has been proposed
    that regardless of solar changes, the current greenhouse gases
    influence (forcing) is higher than the contribution of any solar forcing or factor.

    Reconstruction of solar irradiance using the
    Group sunspot number
    L. Balmaceda, N. A. Krivova and S. K. Solanki

    …”The model predicts an increase in the total solar irradiance since the Maunder Minimum of about 1.3 m{Wm$^{-2}$}. “…

    We have reconstructed total solar irradiance back to 1610. The cyclic variation
    of ER was assumed to be related to the properties of the corresponding
    AR cycle, whose variation can be estimated from the Group sunspot number
    (Solanki et al., 2002). The secular change in the total magnetic flux of the Sun
    and, therefore, in the irradiance is caused by the overlap of the consecutive
    ER cycles. The predicted secular change since 1700 is about 1.3 Wmâ??2. This
    value lies within the range suggested by other recent reconstructions of solar
    irradiance (Foster, 2004; Wang et al., 2005), but is significantly lower than
    the ones obtained in earlier investigations based on stellar data ranging from
    2 to 16 Wmâ??2 (e.g., Mendoza, 1997; Lean, 2000). However, the stellar evidence
    for such a change has been recently critized (Hall and Lockwood, 2004;
    Wright et al., 2004; Giampapa, 2005) and the magnitude of the increase in
    TSI obtained using these results might have been overestimated.”

    Solar variability and global warming: a statistical comparison since 1850
    Advances in Space Research

    Volume 34, Issue 2 , 2004, Pages 361-364
    N. A. Krivova, and S. K. Solanki
    …”We show that at least in the most recent past (since about 1970) the solar influence on climate cannot have been significant. “

    Solar radiative output and its variability: evidence and mechanisms
    The Astronomy and Astrophysics Review 12 (4), 273 (2004)
    …”Empirical associations with solar activity proxies suggest reduced total solar irradiance during the anomalously low activity in the seventeenth century Maunder Minimum relative to the present. Uncertainties in understanding the physical relationships between direct magnetic modulation of solar radiative output and heliospheric modulation of cosmogenic proxies preclude definitive historical irradiance estimates, as yet.”

    And YET another proposed idea on the matter……

    Stardust component in tree rings
    Dendrochronologia 24 (2-3), 131 (2007)
    …”With respect to 11-year periodicity, which is the most prominent one in sunspot number spectrum (Schwabe cycle) it may be said that it hardly appeared in Arctic tree-ring series. Although the 22-year cycles in climatic records are perceivable (it is also evident from our and other results), any physical mechanisms by which a reversal in the solar magnetic field could influence climate are still missing. To our mind, a potential cause of this phenomenon seems to be a variation of stardust flux inside the solar system. The most recent observations in frame of the DUST experiment on board the Ulysses spacecraft have shown that stardust level inside of the solar system was trebled during the recent solar maximum (Landgraf et al., 2003. “…”It is possible that the periodic increase of stardust in the solar system will influence the amount of extraterrestrial material that rains down to the Earth and consequently down to the Earth’s atmosphere and may affect climate through alteration of atmospheric transparency and albedo. “

    Comment by BarbieDoll Moment — 14 Mar 2007 @ 11:33 PM

  65. Quick comments: the dynamics of stars in the galaxy are formally chaotic, but the galactic potential is actually quite smooth on these scales and the Sun’s orbit about the galaxy is quite regular – and 2 billon years is only 8-10 orbits, so backtracking is not hard. Basically the Sun has just been going around in a slightly eccentric orbit about the galaxy.
    Inferring galactic cosmic ray history is much more hazardous, since it depends on local conditions, including crossing of star forming regions, transient hot shocks in the interstellar medium, and large scale events which we do not observe and have no record of in the astronomical data. You can make guesses, based for example of crossing of the galactic plane and the spiral arms, but the timing and amplitude of variations would be highly uncertain for any individual event and not very robust as periodic signals, although it has been tried.

    Comment by Steinn Sigurdsson — 23 Mar 2007 @ 11:27 AM

  66. Are any of the commenters at Chicago who could ask the astronomy people there about this one?

    NOTE: I don’t know what the software will make of this — see the original if you want to rely on things like the tilde and Angstrom symbols to be correct.

    It’s the only article I’ve seen that has both direct observations of our sun over a long time period, and a particular observed variable that might correlate with the Maunder Minimum:

    Sun-as-a-Star Spectrum Variations 1974-2006
    Author(s) W. Livingston, L. Wallace, O. R. White, and M. S. Giampapa
    Identifiers The Astrophysical Journal, volume 657, part 1 (2007), pages 1137�1149
    DOI: 10.1086/511127
    Bibcode: 2007ApJ…657.1137L
    Availability This site: PS | HTML (1.1k) | PDF (1.1M)
    Copyright © 2007, The American Astronomical Society.
    Abstract We have observed selected Fraunhofer lines, both integrated over the full disk and for a small circular region near the center of the solar disk, on 1215 days over the past 30 years. Our full disk results for the chromosphere show that Ca ii K 3933 � nicely tracks the 11 yr magnetic cycle based on sunspot number, with a peak amplitude in central intensity of [tilde]37%. The wavelength of the midline core absorption feature, called K3, referenced to nearby photospheric Fe, displays an activity cycle variation with an amplitude of 3 m� (6 m� center disk). Other chromospheric lines, such as He i 10830 �, Ca ii 8542 �, Halpha, and the CN 3883 � bandhead, track Ca ii K intensity with lower relative amplitudes. In the low photosphere, temperature-sensitive C i 5380 � appears constant in intensity to 0.2%. In the high photosphere, the cores of strong Fe i lines, Na D1 and D2, and the Mg i b lines, present a puzzling signal, perhaps indicating a role for the 22 yr Hale cycle. Solar minimum around 1985 was clearly seen, but the following minimum in 1996 was missing. Our center disk results show that both Ca ii K and C i 5380 � intensities are constant, indicating that the basal quiet atmosphere is unaffected by cycle magnetism within our observational error. A lower limit to the Ca ii K central intensity atmosphere is 0.040. This possibly represents conditions as they were during the Maunder minimum. Converted to the Mount Wilson S-index (H+K index), the Sun center disk is at the lower activity limit for solar-type stars. An appendix provides instructions for URL access to both the raw and reduced data.

    Comment by Hank Roberts — 30 Mar 2007 @ 4:15 AM

  67. Any comment concerning the recent Solar Changes?…_longrange.htm

    The following is an excerpt from the above link:

    The sun’s “Great Conveyor Belt”

    “Normally, the conveyor belt moves about 1 meter per secondâ��walking pace,” says Hathaway. “That’s how it has been since the late 19th century.” In recent years, however, the belt has decelerated to 0.75 m/s in the north and 0.35 m/s (has recently slowed down to 0.25 m/s â�� my comment) in the south. “We’ve never seen speeds so low.”
    And from the next link, it appears there was a failed solar magnetic field reversal.…_backwards.htm

    I thought Solar Activity in the 20th century was the highest in 8,000 years and the solar large scale magnetic field doubled has doubled. Is that correct?

    Evolution of the Sun’s large-scale magnetic field since the Maunder minimum

    A part of the Sun’s magnetic field reaches out from the surface into interplanetary space, and it was recently discovered3 that the average strength of this interplanetary field has doubled in the past 100 years. There has hitherto been no clear explanation for this doubling. Here we present a model describing the long-term evolution of the Sun’s large-scale magnetic field, which reproduces the doubling of the interplanetary field. The model indicates that there is a direct connection between the length of the sunspot cycle and the secular variations.

    [Response:Paleo-records exhibit variations in the isotope compositions dating back several thousands years. One plausible explanation may be a strengthening in the solar magnetism, but I think these hypothese must involve a high degree of uncertainty. As far as I know, there are not many independent evidence which can pin point the exct cause. The idea of a strengthenig solar magnetic field over the past 100 years is based on the so-called aa-index: the difference between the magnetic field measured at near-opposite sides of the pole. I think one should be careful to use the difference of two large and noisy numbers as an indicator, and in this case, the difference must surely be affected by changes in the geo-magnetic field as well. At least over the long run (100 past years). In the last 50 years, even the aa-index doesn’t exhibit much of a trend. -rasmus]

    Comment by William Astley — 30 Mar 2007 @ 9:41 PM

  68. Has any one in this forum reviewed the Wilson H-K study? The Wilson H-K study was a long term study that was started in the 1970s where 70 sun-like stars were studied to learn more about solar variability?

    The following is from a solar review article write by a solar research team. The article summarizes at a high level current solar research findings and understanding. It includes a list of basic questions that this solar research project hopes to answer.

    From page 21
    �The solar cycle has proven to be notoriously difficult to predict. Once a cycle is well under way its smoothed behaviour can be predicted with some reliability using statistical models for the shape of the curve. Predictions prior to the start of cycle are, however, much less reliable and longer range predictions are virtually useless. Currently all methods of cycle prediction are empirical in nature. While we understand many of the processes involved in producing the solar cycle we do not have a physical model that will take initial conditions and predict future behaviour.�

    From page 4-5

    �Solar magnetic fields with their associated forces and electric currents are recognized as being responsible for the Sun�s activity, but the underlying process which create �are poorly understood. Although helioseismology has revealed flows and thermal structures related to magnetic variability, present theoretical models based on these observations can only broadly reproduce the observed magnetic evolution and are far from having predictive capability.�

    �Historical records suggest that the strength of the cyclic magnetic variations may have been different than today and that there may have been associated terrestrial climate changes. Furthermore, sun-like stars are observed to have a wider range of activity than is seen in the Sun, suggesting that current solar behaviour could be misleadingly steady.�

    Comment by William Astley — 30 Mar 2007 @ 9:48 PM

  69. In reply to comment 63 “Why would the GCR count have been lower for the early Earth? If Svensmark is dependent on Solar activity to mediate GCR flux, wasn’t the Sun 25% dimmer than now at 4.5 GYA? Which would mean less modulation, which presumably would result in a GCR flux with less Solar interference. Am I missing something?”

    The solar magnetic field was much stronger in the past due to faster rotation of the sun. Attached is a paper that discusses the hypothesis.

    Comment by William Astley — 30 Mar 2007 @ 10:10 PM

  70. >67, William Astley wrote:…_backwards.htm

    That isn’t a link. I searched the NASA pages, and don’t find anything matching your description.

    “…The Sun’s magnetic poles will remain as they are now, with the north magnetic pole pointing through the Sun’s southern hemisphere, until the year 2012 when they will reverse again. This transition happens, as far as we know, at the peak of every 11-year sunspot cycle — like clockwork.”

    And this, from:

    2006: On July 31st, …. this sunspot was special: It was backward…. “We’ve been waiting for this,” ….”A backward sunspot is a sign that the next solar cycle is beginning.” ….The first spot of a new solar cycle is always backwards. Solar physicists have long known that sunspot magnetic fields reverse polarity from cycle to cycle. N-S becomes S-N and vice versa. “The backward sunspot may be the first sunspot of Cycle 24.” … … For a while, perhaps one or two years, Cycle 23 and Cycle 24 will actually share the sun, making it a hodgepodge of backward and forward spots.

    Possibly you missed that last sentence? We’re in between right now, as expected.

    Perhaps you misread that latter link?

    Comment by Hank Roberts — 31 Mar 2007 @ 9:25 AM

  71. Hi Hank,

    Attached is the correct link to the May, 2006 NASA Solar news release, which notes the solar conveyor has slowed by roughly 65% in the southern hemisphere and 25% in the Northern Hemisphere. Also attached is a paper that describes unusual solar activity, that is concurrent with the changes in the solar conveyor.

    The NASA news link states:

    “Normally, the conveyor belt moves about 1 meter per secondâ��walking pace, says Hathaway. “That’s how it has been since the late 19th century.” In recent years, however, the belt has decelerated to 0.75 m/s in the north and 0.35 m/s in the south. “We’ve never seen speeds so low.”

    Attached is a paper that notes solar observers have found that there are significant asymmetries that are appearing concurrent with the asymmetrical slowing of the solar conveyor.

    From the above paper:

    “The statistical results in sunspot and plage distribution in 1996-2004 â�¦Sunspot and plage area distribution reveal a strong North-South asymmetry of about 0.4 and the period of 7 years for sunspots and of 0.6 and period of about 8 years for plagesâ�¦ The resulting or excess fluxes in 1997-2003 covered by sunspots reveal mostly a positive magnetic flux â�¦ These asymmetries reflect some essential properties of the global solar activity to be accounted for in solar dynamo modelling.”

    Also solar cycle 23 appears to be phased shifted as compared to cycle 21 and 22. See the attached link to a daily solar observation site that also provides a daily and long record of solar activity.

    Comment by William Astley — 2 Apr 2007 @ 8:57 PM

  72. Re: Correct to comment 71:

    Attached is the correct link to the paper “North-South Asymmetry in Solar Cycle 23…”

    Comment by William Astley — 2 Apr 2007 @ 9:44 PM

  73. Don’t miss this one:
    One pole of the sun is cooler than the other. That’s the surprising conclusion announced today by scientists who have been analyzing data from the ESA-NASA Ulysses spacecraft.
    …. The “cool spot” follows the north magnetic pole when the sun’s poles flip. …

    Ulysses’ first polar flybys in 1994 and 1995 revealed the asymmetryâ��”a 7 to 8 percent difference in temperature,” … researchers know the effect is real. Ulysses has returned to the sun’s South Pole in 2007 and “recent observations show that the average temperature … is virtually identical to what we saw 12 years ago,” says Gloeckler.

    Taking the sun’s temperature is tricky business. The spacecraft can’t descend to the surface and insert a thermometer. Instead, Ulysses samples the solar wind at a safe remove of 300 million km. “We measure the abundance of two oxygen ions found in the solar wind. The ratio O6+/O7+ tells us the temperature of the gas,” explains Gloeckler. He is the principal investigator of the instrument onboard Ulysses that does this, the Solar Wind Ion Composition Spectrometer or “SWICS.”

    According to SWICS, the average temperature of the sun’s polar wind is about one million degrees C. But over one pole the wind is about 80,000 degrees cooler than over the other pole.

    Comment by Hank Roberts — 2 Apr 2007 @ 11:48 PM

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