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Why the continued interest?

Filed under: — rasmus @ 9 October 2009

I believe the idea that galactic cosmic rays (GCR) play a role for the present global warming is unlikely to fade soon, despite a growing number of scientific arguments that normally would falsify a hypothesis and lay it dead (see links here and here). Despite all the arguments against the role of GCR, there was a solicited talk about ‘cosmoclimatology’ at the European Meteorological Society’s (EMS) annual meeting in Toulouse. Henrik Svensmark is further invited by the Norwegian Academy of Science and Letters (NASL) to provide an introduction to their seminar on climate. So why is the GCR-hypothesis still perceived as an interesting explanation?

My impression from the solicited talk, is that the confidence in the GCR hypothesis now rests on two points that were made explicit in the presentation, and that we have not adequately addressed here. So, here they are:

Point I: When I asked Svensmark why he presented a curve describing low cloud-cover from the ISCCP – used for correlation study with GCR (link) – that differed from the curves presented at the ISCCP web site (link), he informed me that he used a corrected version that has been published. Nevertheless, the ‘correction’ of the curve is controversial, and the ISCCP team is clearly not convinced, despite the likelihood of instrumental degradation.

Good practice would then be to present all the curves that cannot be ruled out because of errors. When asked why he didn’t present the other cures too, he said that he only wanted to show the one curve. Not a very convincing answer, and not very reassuring.

Point II involves a ‘remarkable’ correlation, meant to demonstrate a link between high GCR flux and cold conditions. This analysis is based on a comparison between band-pass filtered ice-rafted debris from iceberg drifts (Bond, 2001) and Carbon-14 (a cosmogenic isotope) over the last 12,000 years (e.g. after the most recent ice age).

The relationship between temperature and drifting icebergs, however, is complicated and not so straight forward. Icebergs are formed when chunks of ice break off glaciers and icesheets – a process known as ‘calving’.

On the one hand, icesheets and glaciers grow when the accumulation of precipitation at below freezing temperatures (snow) exceeds the summertime melting. Very low temperatures, tend to be associated with low precipitation, however. One the other hand, iceberg calving does not require very low temperatures (as long as the ice is present), but is favoured by reduced friction at the base of ice caps, resulting in a faster flow towards the sea. Melt water can lubricate the ice sheets and hence affect the ice flow.

Once the icesheets have calved and produced icebergs, they will drift according to the winds and ocean currents. The most influential ocean currents for iceberg drift in the North Atlantic include the East Greenland Current EGC), which follows the east coast of Greenland and flows from northeast to southwest, the West Greenland current (WGC) into the Labrador Sea, and the Labrador current (LC), a coastal current following along the perimeter of the Labrador sea basin in an anti-clockwise fashion.

North Atlantic ocean current systems Many of the cores used to study the ice-rafted debris were from locations away from these currents. It is not clear whether anomalous cold conditions produced more southerly winds and ocean currents. However, many of the core locations are associated with a surface flow from the south in the present climate, so it is possible that the icebergs transported by the EGC, WGC, and LC end up in the North Atlantic current. One explanation is that the icebergs got caught in the warm currents from the south, and melted on their way north, but that does not necessary imply cold conditions in that region, as these warm ocean currents provide a heat transport and the melting of icebergs suggest higher temperatures.

Cold conditions favour the formation of sea-ice, which have very different characteristics to icebergs. Sea-ice forms when the sea surface freezes, and can affect the ocean circulation through their effect on salinity. However, sea-ice does not create debris of rocks and minerals, as the icebergs do when the bottom of the sliding icesheets scrape the rocks.

It is plausible that very cold conditions can produce thick sea-ice that will lock icebergs in place near their sources in the Labrador sea and along the east coast of Greenland, but seasonal variations in the sea-ice may also imply open water in the summer. Nevertheless, very cold conditions may not necessarily favour the production of icebergs, as freezing temperatures will prevent the formation of melt water acting as lubrication and the accumulation of ice is expected to be less due to lower precipitation.

In summary, the ‘remarkable’ correlation does not seem to support the hypothesis that high flux of GCR produces a very cold climate. The question is rather whether the ocean and atmospheric circulation were influenced by the level of solar activity and associated changes in the total solar irradiation (TSI) – without involving GCR. After all, GCR is affected by the level of solar activity through its influence of the inter-planetary magnetic field, and anti-correlated with the sunspots.

When taken in the context of the global warming, there are other problematic issues such as the lack of trend in GCR (here and here), stronger warming during nighttime than daytime, large unknowns regarding the physical mechanisms involved in the growth of ultra-small molecule clusters to much larger cloud condensation nuclei (here and here), and questionable data handling and statistical analysis (here). In addition, it is difficult to statistically distinguish between the apparent response to solar forcing in the observations and GCM which do not take GCRs into account (link to a recent paper by Gavin and myself), implying that GCRs are not needed to explain past global temperature trends.

So what makes the GCR-hypothesis so convincing that warrants a solicited talk at the EMS annual meeting and an invited presentation at the NASL? Is the support based on the attention in media, or does it have a scientific basis?

I want a response from the community still supporting the GCR hypothesis, explaining why they find it convincing after all these misgivings. The spirit of science is about discussing different ideas and challenge unconvincing points of view. So far, I feel that many of these issues have gone unheeded outside the climate research community. Perhaps an improved dialogue between various research communities can help resolving these issues – the counter-arguments and GCR hypothesis represent a paradox that should be sorted out if the science is to progress. Either the supporters of the GCR hypothesis should convincingly explain why these misgivings are unfounded or irrelevant, or the GCR hypothesis should be buried. However, I feel that there is a lack of dialogue and willingness to listen, so I think that progress is not likely to happen regarding a commonly accepted solution on the GCR hypothesis.

Update: According to a recent (October 16) news relsease from the International Ice Charting Working Group (IICWG), over 1,200 icebergs drifted into the trans-Atlantic shipping lanes in 2009, making the iceberg season in the North Atlantic the eleventh most severe since the tragic loss of the RMS Titanic in 1912.

P.S. So far in 2009, three articles have been published in the arXhive on GCR and clouds (here, here, here). It is possible that such articles are more accessible to communities other than climate research, and hence enhances the awareness about the controversy surrounding the GCR-hypothesis.


506 Responses to “Why the continued interest?”

  1. 1
    Alan of Oz says:

    GCR won’t go away, neither will Bigfoot, faith healers, creationists, alien abductees, truthers, birthers, the moon hoax, the grassy knoll, Al Gore and the illuminati, horoscopes, electric universe, chariots of the gods, or any other kind of woo-woo physics/politics that people can use to turn a dishonest buck.

    Needless to say I think this article gives GCR proponents more credit than they deserve.

  2. 2

    I think it’s because

    1) Some people are desperate to have global warming caused by something other than CO2. This includes, unfortunately, some scientists who should know better.

    2) Any scientist hates losing an original theory. Van de Kamp kept analyzing his nonexistent planetary system of Barnard’s Star for years after Gatewood and Eichhorn showed it didn’t exist back in 1973. Halton Arp refuses to drop his crazy ideas about cosmology. Chandra Wickramasinghe still clings to his and the late Fred Hoyle’s last version of Steady-State.

    3) Europeans like to show that they’re independent of the US, even in science. As with European journals continuing to publish Arp’s vacuous articles about objects of different red shifts “apparently” physically connected, so, very likely, with Svensmark and his ilk–the more so considering that Svensmark is a European.

    In brief–wishful thinking, authorial pride, nationalism.

  3. 3
    Jeremy says:

    I continue to be amazed that people are willing to shun a relatively well known physical phenomena (the absorption frequencies of CO2) for more and more exotic alternatives. The only thing that unites the alternatives is that they are entirely out of human control.

    Is it human nature to find excuses for things which are almost to big to comprehend. If we were a few hundred years ago, would people be saying that it was “gods will”?

    If so we are facing an uphill struggle, as climate change becomes more apparent people may be less and less willing to believe that they had a part in it and that they can reduce further impact.

  4. 4
    Bengt A says:

    When you reviewed Svensmarks latest paper (here) it seemed that you didn’t fully understand the content (see my comment #32). Svensmark shows very convincing that GCR is correlated to aerosols and cloudiness. Why don’t you start with rereading this latest paper of Svensmark, then you’ll understand why there’s still interest for his hypothesis.

  5. 5
    pascal says:

    hi Rasmus

    I think there is an amplification factor to explain the 0.1°C global temperature between a maximum and a minimum in 11 years cycle.
    With a little model (http://www.climat-evolution.com/article-29141562.html) I find a 3.5 amplification factor (I must be modest however!).
    This doesn’t change the main cause of the long term warming, but it can explain a part of the actual slowing.

  6. 6
    Chris says:

    It’s an interesting subject from a “philosophy of science” point of view! I think there are two points:

    1. The topic is worth pursuing. Svensmark’s studies on gamma-ray induced nanocondensate formation in atmospheric mimics with SO2 and O3 is solid science (papers in J. Phys. Chem. B and Proc. Roy. Soc.). Exploring correlations between solar outputs and climate responses is an important part of earth climate studies and this should include possible contributions from the CRF. So I don’t think there’s a problem with honest scientific study on this subject.

    2. The problem in my mind is (i) the poor scientific approaches amongst some practitioners in this area and (ii) the over-hyping of tentative science while ignoring the larger amount of data that supports something close to the null hypothesis, namely that the CRF has little detectable effect on earth climate responses, and that the contribution to cloud responses is low.

    So it’s not damaging to science to pursue this subject, and I don’t see why people shouldn’t give presentations at conferences on it….of course there should be an honest depiction of the field, and if Svensmark isn’t going to do this, then other scientists should be invited to present their work too! Sadly there are a few characters that are still prepared to misrepresent the science. For example, a truly dismal review on the subject was recently published by one of the people involved in the C-E-R-N “CLOUDS” study.

    Dodgy analysis can “explain” any solar-induced effects by invoking the CRF ( since this parameter marches pretty much in step with the other solar parameters) ….so climate effects produced by irradiance changes can be interpreted as CRF effects without any causal evidence. That seem to be the point of the Erlykin manuscripts you link to which indicate that the observed effects have little CRF contribution and are likely the result of irradiance variations.

  7. 7

    Ken Carslaw offers a partial answer to your question in Nature News and Views of July 2009. (http://www.nature.com/nature/journal/v460/n7253/full/460332a.html) It is a commentary on Pierce and Adams’ modeling study (http://www.agu.org/pubs/crossref/2009/2009GL037946.shtml). I say “partial”, because it only addresses the plausibility of the physical mechanism, while apparently taking the correlations at face value. I discussed the same paper here 6 months ago in my review of aerosol nucleation and GCR. (http://www.realclimate.org/index.php/archives/2009/04/aerosol-effects-and-climate-part-ii-the-role-of-nucleation-and-cosmic-rays/).

    About this paper, Carslaw writes:

    “Their conclusion is clear: CCN concentrations just aren’t very sensitive to the changes in GCRs that have occurred during the twentieth century.”
    (…)
    “Climate modelers are always quick to point out that predictions can be model-dependent. Certainly CCN may
    be more sensitive to the ion-induced nucleation rate in a different model or under conditions not explored by Pierce and Adams. But other global model studies of nucleation suggest that CCN are fairly insensitive to the nucleation rate for a simple reason: during the time taken for nuclei to grow to CCN sizes, coagulation depletes particle concentrations — just as raindrops are always fewer in number than cloud drops. Unless there is some as-yet-undiscovered process that accelerates the growth of a few charged nuclei all the way up to CCN sizes, this low sensitivity is likely to be a robust conclusion.

    Despite this result, it is likely that a cosmic ray–cloud–climate connection will continue to be explored, for two reasons. First, scientists continue to be intrigued by correlations between cosmic rays, Earth’s electrical state and climate variables (clouds, precipitation, drought and so on) on timescales from hours to millennia.(…) The second reason that GCR–cloud physics will remain a hot topic is that we have yet to explore all the possible mechanisms. Attention may now shift to the ‘ion–aerosol near cloud’ mechanism.”

  8. 8
    pjclarke says:

    “Our main weapon is the correlation between low cloud and GCRs’ and the historical correlation with icebergs.. er…

    Our two main weapons are the correlation between low cloud and GCRs’ and the historical correlation with icebergs, and the reduction in cloud water vapour after Forbush events … er ….

    Our three main weapons are …”

    Seriously, was the Forbush paper not mentioned as supporting evidence?

    “Close passages of coronal mass ejections from the sun are signaled at the Earth’s surface by Forbush decreases in cosmic ray counts. We find that low clouds contain less liquid water following Forbush decreases, and for the most influential events the liquid water in the oceanic atmosphere can diminish by as much as 7%.” http://www.agu.org/pubs/crossref/2009/2009GL038429.shtml

    It seems to be considered a done deal in Tehran

    Phil Clarke.

    Thanks to Rasmus and apologies to the Pythons.

  9. 9
    Bengt A says:

    Seems that my link does not work? Can you fix it? Would appriciate a preview!

  10. 10

    There’s one thing about ISCCP cloud trends that I rarely see mentioned; the possibility that they are not real, see Evan et al. (2007):
    http://www.aos.wisc.edu/~dvimont/Papers/Evan_etal_GL028083.pdf

    “Here we show that trends observed in the ISCCP data are satellite viewing geometry artifacts and are not related to physical changes in the atmosphere. Our results suggest that in its current form, the ISCCP data may not be appropriate for certain long-term global studies, especially those focused on trends.”

  11. 11
    Pekka Kostamo says:

    Another paper by Svensmark is mentioned in a recent Science Daily:
    http://www.sciencedaily.com/releases/2009/08/090801095810.htm

    According to this abstract, a clear impact of Forbush events can be detected if a delay of 7 – 8 days is allowed for aerosol growth to produce water vapor condensation nuclei.

    I recall some earlier work investigating the same mechanism. The test then failed as no correlation was found. However, the growth period was limited to shorter values (0 – 5 days).

    Forbush events are transitory of course, but they might be suitable for evaluation of the proposed mechanism and indicative of the impact IF there were long term changes in cosmic radiation.

  12. 12
    Jimmy Haigh says:

    Are you a cosmologist? Are you qualiied to debate this issue?

  13. 13
    rasmus says:

    I think I did understand the important points – namely that if the molecule clusters were to grow and become CCNs, then one should be able to detect a change in aerosols at all sizes within the relevant size range and with appropriate phase change. Even if the GCrs were to affect CCNs and low clouds, there is still a problem when it comes to explaining the recent trend in global mean temperature without a correspoding trend in GCR.

  14. 14
    CM says:

    I’m afraid it’s not really about the data. It’s about the unorthodox scientist as hero, challenging the establishment with a cool new idea. It’s about the underdog against the arrogance of the establishment. It’s about publicity, self-promotion, and sexy press releases. It’s about insisting relentlessly from publication to publication that a link has been shown, and a theory is gaining strength. It’s about writing a popular book about oneself, ignoring every objection that has been raised except the one for which one happens to have a good reply. And it’s about wishful thinking that this somehow means greenhouse warming isn’t happening. People want Svensmark to be right.

    But about the data, regarding Svensmark’s “corrected” ISCCP curve referred to in point. 1: Do you know if it’s the one published in Marsh and Svensmark 2003 (fig. 1a), previously discussed here, or is there a later publication?

  15. 15
    Mark says:

    Heck, you might as well ask why the idea that scientists who don’t follow “the AGW dogma” are silenced still exists, despite not one coming forward in a query for one direct example (as opposed to “I know someone who has, but I won’t name them”) still exists.

    Any straw possible.

    Think of a man falling from a great height: grabbing handfuls of nothing to try and slow him down. Heck, he’s got nothing to lose but his dignity, and he doesn’t care about that.

  16. 16
    Mark says:

    “Svensmark shows very convincing that GCR is correlated to aerosols and cloudiness.”

    Bengt, can you then answer why one curve was produced to show this convincing correlation when that was one of many possible curves that fit the data with the known uncertainties?

    If you are convinced by the correlation, would that correlation continue if you’d seen all equally valid corrections?

    In Carl Sagan’s Cosmos series, he goes on about ET Encounters and how the best example has a set of stars that, when lines drawn between them a certain way, match apparently very well to stars visible many light years away, including some stars that were at that time unknown.

    But he showed that if you removed the lines given and draw other ones, the fit is much poorer and if you took away the lines joining them up, there was no apparent fit between the two star charts.

    Have you likewise been hoaxed by selective reporting?

  17. 17
    Mark says:

    “I’m afraid it’s not really about the data. It’s about the unorthodox scientist as hero”

    However, if the unorthodox hero is promoting a conspiracy in the two towers attack, they don’t get the hero status…

    (not saying that there was collusion, just pointing out that many of the same people proclaiming a socia list worldwide conspiracy on AGW are also the same people who pour much scorn on the much smaller US/TwinTowers conspiracy theories)

  18. 18
    PaulM says:

    Rasmus, I found one more recent paper on the archive,
    “The role of cosmic rays in the Earths atmospheric processes”
    arXiv:0908.4156

  19. 19
    Michael says:

    have a look at this graph:

    http://i37.tinypic.com/24wvyth.png

    it shows the t trend in the alpine region (only one station here shown today) for 100a. the hole warming of almost 2,0°C can be explained by changes in circulation types. ironicly the PIK (Rahmstorf & Co) have datasets of cirulation types for each day beginning in 1880 (ed. southwest=warmingaverage 3,21°C, northeast=coolingaverage -2,45°C, there are 30 different circulation forms definated). we bild an average for every day and can show, that there is a significant trend in more warming circulation forms and less cool types. the graph shows in black the messured temp. (year average) and in red the warming caused by circulation trends. we now go on to do this with 100 station in middel europe and our first results show, that we do not need any radiation forcing to explain the hole warming in the 20th. century.

    (sorry about my english, i´m from austria and not realy used to write in your language…)

  20. 20
    Esop says:

    Svensmark claims that global warming is over, that the world is cooling and will continue to cool, due to the record low solar activity. Despite this, record high temperatures are being recorded over the past months. Does this not weaken his arguments a tiny bit?

  21. 21
    Hank Roberts says:

    The first 10 comments were high signal, low noise, low snark.

    Rasmus requested:

    “a response from the community still supporting the GCR hypothesis,
    explaining why they find it convincing.”

    They may respond – if the rest of us butt out, shut up, and don’t attack them.

    Gavin, I suggest your machete for editing, for this thread. I’ll shut up now.

  22. 22
    Lou Grinzo says:

    CM[14}: Well said (about motivations).

    I recently spoke with a psychiatrist at a social gathering. She was not deeply steeped in climate issues, and after hearing how adamant the deniers are and their tactics (particularly online), she made the casual observation that they do it “because it’s fun.”

    I think that neatly describes those without a strong financial interest, e.g. fossil fuel company execs and those they pay to obfuscate.

  23. 23
    bushy says:

    The proof is in the pudding as they say. Right now there is an increase (marked) in GCR counts. Pull up a multi- year graph here http://cosmicrays.oulu.fi/ for instance. It will, given a suitable lag period prove or disprove this theory.

  24. 24
    Mark says:

    Hank, #17 was well On topic. It’s why Rasmus wanted to know why just one graph was shown and why a *skeptic* would ask “would that correlation work with any of the others?” and if not, “why is that one the right one, then?”

  25. 25
    Mark says:

    Grrk. Editors change that to 16…

  26. 26
    John says:

    Apparently CERN did not get the letter that the science is complete on cosmic rays.

  27. 27
    El Cid says:

    Look, if cosmic rays can give the Fantastic Four super-powers, they have to have some sort of effect on the environment.

  28. 28
    JK says:

    “stronger warming during nighttime than daytime”

    I was wondering, and this seems as good a place as any to ask, is it true that this effect has recently weakened, and if so is there anything much to say about it?

  29. 29
    dbleader61 says:

    Gavin,

    I am a skeptic/denier (No Lou Grinzo #22, it’s not for fun – I am quite distressed by it all) but do check out RC from time to time – (0f course I spend much time on CA and WUWT) so I have to say I APPRECIATE your invitation re GCR. Can’t say I put much stock into GCR as influencing climate either, but hell, you never know. It does deserve to be examined. Thanks.

  30. 30
    MarkB says:

    If cosmic rays are at very high levels now

    and

    Cosmic rays increase low-level cloud cover, which is a significant cooling influence, and GCRs explain most of the temperature trend

    then why is global mean temperature around record levels right now? el Nino is fairly weak at the moment. It seems those promoting GCRs tend to argue against the net human influence on climate. But global mean temperature data doesn’t seem to work in their favor. Temperatures should be plunging. It hasn’t happened.

  31. 31
    David B. Benson says:

    Tung & Cabin (2008) determined a rather large variation in global temperature over the solar cycle using 50+ years of data. In the appendix, a standard heat transfer equation is presented. Using other works, they calculate that this simple transfer of heat in and out of oceans agrees fairly well with their observations. They explicitly note that no exoctic mechanisms, such as GCRs, are required to explain the observed variation.

  32. 32
    Bengt A says:

    Some of you seem to be upset about Svensmarks opinion piece in Jyllandsposten. It’s understandable, but you have to acknowledge that there are some serious evidence for GCR impact on aerosols and clouds in his latest paper. Forbush decreases seems to affect low cloud cover and aerosols and cloud water content. Svensmark (or someone else) is still to prove how much this affects the climate. But the connection sun => GCR => aerosols => clouds is real.

  33. 33
    Mark says:

    “Can’t say I put much stock into GCR as influencing climate either, but hell, you never know. It does deserve to be examined.”

    But already the examinations say “it’s wrong”, (see MarkB’s post #30).

    So when does it become “yeah, we do know”? Or will it deserve to be examined and trotted out as a counter to CO2′s effects forever?

    “It deserves to be examined” has already been solved: it’s been examined. Rasmus’ query is why do people still want to examine it again and ignore the results of previous examination.

  34. 34
    Jeffrey Davis says:

    Isn’t the argument for GCR the equivalent of a perpetual motion machine. Tiny bits of energy producing lots of warming?

    I want a franchise.

  35. 35
    Lynn Vincentnathan says:

    I’ll tell you the real reason why so many find the galactic cosmic ray hypothesis of global warming so compelling. It’s because CO2 and other GHGs are not the real drivers of global warming — it’s us, people, we’re the ones emitting the GHGs (at least in this episode of warming), we, you and I, are the GW forcings.

    People generally do not want to admit they might be causing something bad and engage in “blame shifting” (rather and “taking responsibility”). Since GCRs can’t argue back and present their own reasons why they’re not causing GW, they make easy fall guys for denialists. The poor & powerless also get blamed by people who might accept anthropogenic GW, as in “it’s not me or my children, it’s the poor and their children who are causing it. Why do they have so many children?”

    The narcissists (oh, I meant to say “denialists”) also like to take undue credit for good things.

    Even ordinary people often unbeknownst to themselves engage in false attributions (see “attribution theory”). If one from a disvalued group does something wrong, that’s just how those folks are, inherently bad; if one from one’s own group or oneself does something wrong, then it is just a fluke or an anomaly. If one does well on a test, it’s due to intelligence & despite not really studying hard; if an opponent does well on a test, it’s due to luck or extremely hard work. If one fails a test, it’s due to one’s total lack of effort or bad luck; if an opponent fails, it’s because he’s stupid.

    So any and all data pointing to GW is just weird anomalies with the overall trend “not warming, maybe even cooling.” And if one accepts GW, then it is due to some other “not me” factor, certainly not anthropogenic causes. And if it really is AGW, then it’s due to the other people, NOT ME! Or, if it’s due to me, then it will actually be having positive, not negative, effects — long growing seasons; CO2, we call it life…..

    So I hope that answers the Q about why the GCRers find the GCR hypothesis still convincing after all these misgivings.

  36. 36
    sidd says:

    Mr. Benson: Re Tung and Cabin

    I take it you refer to
    http://www.amath.washington.edu/research/articles/Tung/journals/solar-jgr.pdf

    Thanx for directing me to the paper. I note that they arrive at they agree with consensus estimates of feedback (1.7<f<4.7) and sensitivity to doubling CO2 at f*1.4K(2.3 to 6.4K) and that they are more confident of their lower bounds are harder than upper bounds. Not to mention the nice pictures of the difference between solar max and solar min at the poles, and meaty discussion of Linear Discriminant Analysis.

  37. 37
    Fleury says:

    There are a lot of people who can’t support the idea of human responsibility in the global warming because if they accept this idea, they must accept the following involvements :
    first the so called “market” is responsible for the mess and is inefficient to solve alone the problem,
    second the states, the public administrations, you know, the guys who are generally elected by people like you and me, must carry out some interventions in different economic fields in a way or in an other to solve the problem.
    As some scientists hate losing their theories, some people are able to deny the reality because otherwise the core of their economical and social beliefs would be damaged. In these conditions, anything which has a scientific skin and which participates to the denial is good for them.

  38. 38

    Here are comments from a well respected source:

    “The mechanism by which cosmic rays might affect climate is as yet purely speculative and unquantified. While it has long been known that radiation could form ions and, in theory, ultimately lead to cloud formation, the importance of this process compared to all the other major sources of particles and cloud condensation nuclei has not been proven. Indeed, there is no evidence that the flux of cosmic rays has decreased over the last 30 years.

    Even if cosmic rays have a detectable effect on climate (and this remains unproven), measured solar activity over the last few decades has not significantly changed and cannot explain the continued warming trend. In contrast, increases in CO2 are well measured and its warming effect is well quantified. It offers the most plausible explanation of most of the recent warming and future increases.”

    http://www.metoffice.gov.uk/climatechange/guide/bigpicture/myth1.html

    Why the continued interest? We know that GCMs are part of the electromagnetic spectrum. We can probably conclude that those who propose that cosmic rays significantly effect current climate conditions are part of the head in the sand spectrum.

  39. 39
    Jim Galasyn says:

    dbleader61, can you describe what you find “distressing” about climate science? Are there any other sciences that have this effect on you?

  40. 40
    Mark says:

    “Some of you seem to be upset about Svensmarks opinion piece in Jyllandsposten.”

    Why do you see upset?

    Amazement that opinion pieces on such flimsy hypotheses gets so much traction CAN look like “upset”. Many of the questions prompted are the same: why is he saying this? et al.

    “Forbush decreases seems to affect low cloud cover and aerosols and cloud water content.”

    And here’s another example of amazement.

    Why is it this “seems” gets a bye for the denialists when there are still people saying that CO2 is saturated and so it can’t be causing warming. That it does is central to our ability to guess at the constituents of the stars: without optical depth varying with concentrations of saturated absorption bands, we cannot see the content of our own star, let alone a more distant one.

    “Where are all the skeptics gone?”

    Which is quite plaintive and can be seen as “upset”.

    “Svensmark (or someone else) is still to prove how much this affects the climate.”

    How?

    Again “skeptics” still say “models are not science”, so how will he or anyone else manage this? We can’t create GCR’s, so no proof is possible without it.

    They also hound round saying “well, you don’t really know how clouds form, do you, so you don’t know ANYTHING about what the weather will do”. But not here.

    Where have all the skeptics gone?

    RodB? Tilo? Anyone?

    A single paper is produced to disprove the 98 hockey stick. It has errors. But that single error-filled paper is still enough to discount summarily all other reconstructions, even those that avoid the dissenting papers’ proclaimed problems with the 98 paper.

    Yet when it comes to GCR’s causing warming or cooling, ten papers are not enough to change that one. Even though you yourself say “seems”.

    Where have all the skeptics gone?

  41. 41
    David B. Benson says:

    sidd (36) — There are at least two other related papers on that website, one earlier and one later. I took some objection to a conclusion of the later paper, worked out rather painfully with some high powered assistance here:
    (Avoiding the spam filter: find the link to globalchange on the side bar, go there and paste in
    /browse_thread/thread/2480211070fee638
    — it’s about the 12th newest thread.)

    By the way, the paper I was referring to is
    K.K. Tung and C.D. Camp; 2008: Solar Cycle Warming at the Earth’s
    Surface in NCEP and ERA-40 data: A linear Discriminant Analysis,
    Journal of Geophysical Research, 113, D05114, doi:10.1029/2007JD009164
    which is slightly different than the paper in the link you found.

  42. 42
    RichardC says:

    21 Lou said, “I recently spoke with a psychiatrist at a social gathering. She was not deeply steeped in climate issues, and after hearing how adamant the deniers are and their tactics (particularly online), she made the casual observation that they do it “because it’s fun.”

    I think that neatly describes those without a strong financial interest, e.g. fossil fuel company execs and those they pay to obfuscate.”

    Yep, that neatly describes many if not almost all the regulars on this site. After all, it’s fun for both sides.

  43. 43
    Jimbo says:

    The debate is over because the BBC says “What happened to global warming?” “…what is causing global warming is far from over.”
    http://news.bbc.co.uk/2/hi/science/nature/8299079.stm

    Scientists should always be sceptical.

  44. 44
    arch stanton says:

    It seems clear that GCRs are not the primary driver of twentieth century warming. Perhaps they are part of the source of the “noise” of the last decade however. For this reason further research seems warranted.

  45. 45
    Mark says:

    “Forbush decreases seems to affect low cloud cover and aerosols and cloud water content.”

    Hang on, I’ve just noticed.

    How can GCR’s create more cloud water content? A nucleation site draws vapour from the surrounding air, reducing the vapour content of the surrounding air and enhancing evaporation from any nearby water (like, say, a cloud condensation nucleus droplet). It’s the reason why you don’t get drizzle from high clouds: they don’t last long because they evaporate quickly (large surface area to evaporate from, small volume to evaporate and the high curvature means the water molecules at the surface are already under stress to leave).

    So how can it create MORE cloud *and* more water in that cloud? It doesn’t get to ground level, pick up some water and bring it back, does it?

  46. 46
    Lynn Vincentnathan says:

    I guess one answer to the GCRers is “Okay, let’s assume you may be right. That doesn’t disprove that GHGs are contributing to GW (which has very sound theory behind it, like laws of physics, unlike the shaky GCR hypothesis). But if you are right, we really can’t do much to stop GCRs, so it just means we have to work all that much harder to reduce our GHG emissions, not only to offset our contriubtions to the warming, but to offset the increased warming GCRs may be causing.”

  47. 47
    Thomas says:

    I find the continued insistence of GCRs puzzling. There is another solar activity issue that is more compelling, and that is solar UV. While total solar irradiance varies only a tiny amount with solar magnetic activity, UV, and especially the harder frequencies of UV vary subtantially with the solar cycle. So why do these guys keep going back to GCR’s, when an effect which does affect upper atmospheric chemistry is there?

    And do we have any real handle on what changing the amount of UV might do to the climate?

  48. 48
    Eli Rabett says:

    Speculations about cosmic rays and climate have been around since the 1950s. As soon as detailed mechanisms are proposed they get shot down. Svensmark & Co have revised their claims quite a few times. Each time the “correlation is really really good”.

    IEHO there are two things at work here. First there is a group of upper atmosphere and cosmic ray folk who really, really want what they study to be important. Second, a bunch of them are in Denmark. The CERN experiment is a bone tossed to the Danes.

  49. 49
    Mark says:

    ” And do we have any real handle on what changing the amount of UV might do to the climate?”

    On a very gut feeling, since the reason why there is a tropopause, above which temperatures rise considerably is that UV light is disassociating O2 and O3 molecules, that most of the energy goes there.

    Note that as a proportion of power in that band, radio waves are massively variable.

    Just as comparing it to the overall heat budget of the sun makes it a small variation. The values are something I would once have had in my head, but google search isn’t good enough to get me a link.

  50. 50

    Fleury:

    first the so called “market” is responsible for the mess and is inefficient to solve alone the problem,

    While I agree that massive government intervention is needed to fix this problem quickly, blaming “the market” for global warming is not fair. The Communist countries burned as much fossil fuel as they could, too. And the opposition to AGW theory is coming from the huge cartels which dominate the US and other economies–hardly a free market, since these firms generally act collusively and influence laws in their favor. Private ownership doth not a free market make. For a free market, you want conditions such as a large number of sellers and buyers, easy entry to either group, lack of government price-fixing, etc., etc.


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