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Comments 127851 to 127900:

127851. Robbo the Yobbo at 07:29 AM on 16 July 2009
        Climate time lag
        'What you said suggested that the climate was selectively reacting to different radiative forcings. AFAIK, there is nothing in the scientific litterature that could support that. A radiative forcing is a radiative forcing. Otherwise pointers would be appreciated.' What I said was: 'The point is that 0.08 degrees per decade (and declining sensitivity to greenhouse gases) is not sufficient to warrant restricting the economic aspirations of billions of people.' I am sure what I said implies that the climate response to a quanta of increase in greenhouse gases declines exponentially as gas concentrations increase. If we add x amount of greenhouse gases to the atmosphere there is y response. If we then add another x quanta - the response is less than y. Nothing magical about it. I very patiently explained the very basic atmospheric physics and suggested you look it up on Wikepedia. What is your problem? The EPA report is worth reading. I assume you haven't read it? I referred the the UAH temperature graph available on Roy Spencers website. It is also available on a NASA website. I have just had a look the Spencer CO2 blog. My first thought was - really 300 ppmv CO2 is background for an interglacial - but 380 ppmv is probably anthropogenic. I don't think Spencer claims to be convinced otherwise. Dr Roy Spencer has always been measured and rasonable. 'Roy W. Spencer received his Ph.D. in meteorology at the University of Wisconsin-Madison in 1981. Before becoming a Principal Research Scientist at the University of Alabama in Huntsville in 2001, he was a Senior Scientist for Climate Studies at NASA’s Marshall Space Flight Center, where he and Dr. John Christy received NASA’s Exceptional Scientific Achievement Medal for their global temperature monitoring work with satellites. Dr. Spencer’s work with NASA continues as the U.S. Science Team leader for the Advanced Microwave Scanning Radiometer flying on NASA’s Aqua satellite.' The freezing point of carbon dioxide is -57 degrees centigrade. The lowest temperature ever recorded was -89.2 at Vostok in 1983. CO2 snow seems broadly feasible - although I am not sure that I would claim any climate implications - other than it is bloody cold in Antarctica. Riccardo assumes that autocorrelation should be minimal - in fact it is the multi decadal signal in the data that is important, i.e. we are looking for the signal in the variation and not a period of approximately linear change. He assumes that the start and end points are arbitrary whereas they correspond to phase shifts in global climate as identified in the Swanson paper and as is evident in climate records. That is transitions in the mid 1940's, the mid 1970's and following 1998. He also assumes that variability is random noise whereas in fact it is temperature response to clouds, ENSO, volcanos etc. So in fact variation is meaningful and precision is limited only by the errors of measurement. 1998 is far from cherry picking - it was the end of one climate state and the beginnning of another. Very important. Swansons explanation is that the 1998 El Nino was so big it flipped climate into a new phase. I think clouds may be the driver - but feeding into a dynamic and resonant ocean and atmosphere. "But to be rabbiting on, at such length, about these minor matters, while the great big CO2 elephant in the room keeps trumpeting for attention, is a sign of the same old denialism that is based on an unshakeable ideology that either (or both), humans can't affect a god-given home; or unfettered capitalism based on an ever increasing dependence on burning fossil fuels is the only way to conduct human affairs" Does Thumb's post apply to the insistance that denialists are Christian and capitalists? I was trying to be relaxed and amusing on Riccardo's post. Perhaps I should have entered into a more serious statistical discussion. Nothing you are saying has any scientific content at all.
127852. nbrack at 06:58 AM on 16 July 2009
        Al Gore got it wrong
        "The film said a sea-level rise of up to 20ft would be caused by melting of either west Antarctica or Greenland in the near future. The judge ruled that this was "distinctly alarmist" A 2007 report by the IPCC explained the maximum we can expect the sea level to rise is 1 foot 5 inches, alarmist indeed. http://www.youtube.com/watch?v=rImKRTBwXkc&feature=related This speaker holds similiar opinions in his book, and talks about the energy crisis, good video
127853. chris at 06:36 AM on 16 July 2009
        Climate time lag
        Re #60, Shawnet Yes I suspect that this discussion has reached the end of the road. I'm going to summarize the conclusions as I see them. 1. While we've been discussing minutae of the solar/cloud/climate response the obvious thing that I think we agree on is that there has been no significant secular trend in the cosmic ray flux (CRF) since detailed measures began in 1958. So the very large global scale warming of the last 30-odd years has nothing to do with the CRF. It's worth re-emphasising this. After all on the blog page you referred us to, Shaviv asserts without evidence that cosmic rays "…does however explain most of the solar-climate link and a large fraction (perhaps 2/3's of the temperature increase over the 20th century)." Each of those sub-statements is a misrepresentation of scientific knowledge on these subjects (role of CRF in solar-climate link; role of CRF in 20th century temperature increase), as is readily apparent by looking at thr science, and it's worth being clear about the difference between what some people assert on blogs and what a dispassionate assessment of the scientific literature "says". 2. There's now substantial published analysis of CRF-solar cycle-cloud relationships. Early studies indicated a correlation between the CRF and the low cloud cover (LCC) component of the International Satellite Cloud Climatology Project (ISCCP) infra-red (IR) product during 1983 through 1994 (solar cycle 22) [Marsh and Svensmark, 2000]. Kristjánsson et al. (2002) extended the analysis through 2000, and showed that the correlation becomes poor after 1993. They also showed (i) that the correlation with the more reliable[*] ISCCP-IR/vis product was considerably poorer still, and (ii) that rather than correlating with the CRF, the correlation with the solar cycle seemed to match the irradiance changes rather than the CRF changes. This disconnect between CRF variation and LCC has become more apparent as time has progressed. 3. Svensmark and Shaviv have pretty much withdrawn from scientific analysis of these direct CRF-cloud relationships, advocating for their hypothesis from web blogs and web reports, while persuing other subjects (admirable basic physics of CRF effects on aerosol micro-nucleation; stellar winds and such like). In the meantime the ISCCP data has been extended to 2008, and two groups in particular have attempted to pull out the intricacies of any CRF-cloud/solar cycle-cloud relationships. 4. Each of these groups (Wolfendale/Sloan and Kristjánsson) have published several detailed analyses of possible solar cycle-CRF-cloud relationships (see references below), and have independently come to a similar conclusion. This is that any apparent correlation observed between the solar cycle and LCC changes arises from the irradiance component of the solar cycle and not the CRF component. Any LCC variation seems not to be a response to changes in the CRF. 5. Does LCC correlate with the solar cycle? The correlation is good during the early part of the ISCCP record (solar cycle 22) but the relationship begins to weaken around 1994, and the correlation from then to the present becomes progressively weaker. This is particularly apparent when the more reliable ISCCP-IR/vis product is used. There isn't much of a correlation between the solar cycle and ISCCP-IR/vis at all: one can inspect the ISCCP data from the ISCCP depository here: http://isccp.giss.nasa.gov/climanal7.html 6. For this reason, most analyses make use of just the period of solar cycle 22 (up to around 1994) and using the less reliable ISCCP-IR data, to investigate possible causal relationships. As indicated in [4.] above the evidence indicates any solar-cycle-LCC correlation isn't causal with respect to the CRF; apparent correlation between CRF and solar cycle seems to be an artefact of the fact that the CRF correlates with the solar cycle. 7. Direct empirical analysis of the CRF-LCC hypothesis therfore leads to the conclusion that there isn't a detectable causal link between CRF and LCC. However there may be a relationship between LCC and solar irradiance changes through the solar cycle. 8. Note that the two main advocates of the CRF-cloud-climate hypothesis don't address these subjects by doing relevant science, but either ignore these comprehensive analyses or snipe from web blogs. Ignoring the proper scientific channels and resorting to web blogs and web reports has the advantage for advocates that bogus arguments can be used to attempt to counter these analyses, and whenever a scientist might take the time to point out the errors on the blog, they can just be ignored. 9. Forbush events. Inconclusive so far. Some tenuous evidence that cloud cover might change in response to very large short term drops in the CRF. [*] according to the ISCCP scientists (Rossow and Schiffer, 1999), the ISCCP-IR/vis data is a more reliable product that the ISPCC-IR data set, since (i) IR cannot distinguish low clouds from any region of the earth's surface below that has trhe same temperature, and (ii) thin cirrus clouds can be misassifned as low level clouds. Rossow and Schiffer (1999) Advances in understanding clouds from ISCPP. Bull. Am. Met. Soc. 80, 2261-2287 Kristjánsson, J. E., A. Staple, J. Kristiansen, and E. Kaas, A new look at possible connections between solar activity, clouds and climate, Geophys. Res. Lett., 29(23), 2107, 10.1029/2002GL015646, 2002. Kristjansson JE, Kristiansen J, Kaas E (2004) Solar activity, cosmic rays, clouds and climate - an update Adv. Space Res. 34, 407-415. Kristjansson JE, Stjern CW, Stordal F, et al. (2008) Cosmic rays, cloud condensation nuclei and clouds - a reassessment using MODIS data Atmos. Chem. Phys. 8, 7373-7387. Erlykin AD, Sloan T, Wolfendale AW (2009) Solar activity and the mean global temperature Environ. Res. Lett: 4 art # 014006 Sloan T, Wolfendale AW (2008) Testing the proposed causal link between cosmic rays and cloud cover Environ. Res. Lett. 3 art. # 024001 A.D. Erlykin, T. Sloan, A.W. Wolfendale (2009) The search for cosmic ray effects on clouds J. Atmos. Solar Terrestr. Phys. 71, 955-958 A.D. Erlykin, G. Gyalai, K. Kudela, T. Sloan, A.W. Wolfendale (2009) Some aspects of ionization and the cloud cover, cosmic ray correlation problem J. Atmos. Solar Terrestr. Phys. 71, 823-829
127854. Thumb at 03:36 AM on 16 July 2009
        Climate time lag
        "You left one important, strong human ideological tendancy out." Nothing says Strong Science quite like inferring that your adversaries are communists. Heckofa rebuttal. Well played.
127855. Philippe Chantreau at 02:50 AM on 16 July 2009
        Climate time lag
        What you said suggested that the climate was selectively reacting to different radiative forcings. AFAIK, there is nothing in the scientific litterature that could support that. A radiative forcing is a radiative forcing. Otherwise pointers would be appreciated. It also suggested that the response to a given forcing could vary, which would require much more elaboration (your post #66 vaguely describes how the forcing could vary, not the response). Perhaps it was just the wording leading me to interpret that way. However, I see nothing in your post #66 that I was not already aware of, nor anything that could definitely clarify your statement in #62. In my opinion, Riccardo is not torturing the data at all, he is using normal rules of statistical analysis. These rules apply for data in general, why would they not apply to temp. time series? Not paying attention to the residuals, autocorrelation, standard deviations would really be torturing the data. As for not trusting you, I see a number of reasons for that. You referred to blog postings by Spencer, who has clearly not a clue of what he does with his own maths on occasions. Spencer who has gone off the deep end with the CO2 cycle theories that he puts on the intertubes (but refrains to put up for peer-review). Those even scared "skeptics" on WUWT, a blog where it is considered acceptable to ponder whether or not Antarctica is cold enough to make atmospheric CO2 snow out of the air (seriously, they had a post on that, many thought it was plausible). That even these bozos would say Spencer should shut up on the CO2 cycle is telling, methinks. Also you cite that ridiculous (for a lack of a stronger word) EPA suppression story, which is such an empty pile of nonsense it's not worth discussing at all. Your insistence on cherry picking 1998 is no more reassuring. Thanks for the advice, but really, I'm safe. I'm not about to trust the Yobbo from the blog (albeit a better one) on any scientific matter. Nothing personal, I wouldn't really trust anyone else either. I form my own opinion.
127856. thingadonta at 19:34 PM on 15 July 2009
        Climate time lag
        re61 David Horton "But to be rabbiting on, at such length, about these minor matters, while the great big CO2 elephant in the room keeps trumpeting for attention, is a sign of the same old denialism that is based on an unshakeable ideology that either (or both), humans can't affect a god-given home; or unfettered capitalism based on an ever increasing dependence on burning fossil fuels is the only way to conduct human affairs" You left one important, strong human ideological tendancy out. Socialist-determinism, the worst historical distorter of data on record. (eg eugenics, communism, race-based Nazism). I think some communist propaganda posters depict capitalism as a big elephant, but I don't know what they would have made of human-induced global warming... It is amazing, that just like Karl Marx, you just cant see the weaknesses and common disortions in your own side of the argument. (eg 1. Karl Marx was so blind he scoffed at the idea that factory managers would be tempted to distort/exploit the new 'economic system', not to mention the 'radical intellectuals' themselves- just like you seem to have trouble doing...) (eg 2. check out Pipes of Harvard Uni's book on Communism-who claims that communism was largely founded by radical intellectuals-just like the human induced C02 warming agenda)
127857. Robbo the Yobbo at 19:07 PM on 15 July 2009
        Climate time lag
        Riccardo. You are torturing the data - up against the wall MF! Cheers Robbo
127858. Robbo the Yobbo at 19:01 PM on 15 July 2009
        Climate time lag
        Philippe, This is simply a fundamental concept of atmospheric physics. Greenhouse gases are transparent to shortwave radiation and opaque to specific bands of infrared radiation depending on the gas. As there are already gases in the atmosphere - some of the radiation is already blocked. More gas doesn't linearly decrease transparency of the atmosphere to IR - rather the transparency exponentially declines with each additional molecule. Once the IR window is closed - no amount of addtional greenhouse gas will trap more IR - but we are not there yet. In fact, I once calculated what would happen to global temps if the IR window was closed completely (it's an engineering thing) - and I don't think we want to go there. It is why there is a quasi linear response to an exponential increase in greenhouse gases. Yes - climate does respond to anthropogeninc greenhouse gases - I'm just not sure what it is. The upper limit appears to be the trend between 1946 to 1998 rather than 1976 to 1998. This makes a difference between - oh hell - we are all going to die and we have some time for human technological capacity to make a difference. Instead we have all these people - including the UN - who are wildly exaggerating the threat - and they admit to that all the time - and saying they can solve the problem with more taxes and bigger government. Excuse me for being hyper skeptical. Trust me - I'm a scientist/engineer. No don't do that - look it up on Wikepedia. Cheers Robbo
127859. Riccardo at 18:43 PM on 15 July 2009
        Climate time lag
        One need to be carefull before coming to conclusions from linear trends. Indeed, the choice of the time interval is not neutral and can not be chosen arbitrarly. Also, the natural variability needs to be taken into account. Luckly there are statistical criteria to be met. As for the first issue (the time interval) you need to look at the residuals and no trend must be present. You can also look at autocorrelation and be sure it is minimal. This criterion excludes both '50-'97 and '45-'98 intervals. This does not mean you can't use them but you cannot draw robust conclusions, just a rough average trend. Using GISS data and trying to go as far back in time as possible, I found the interval 1970-2008 consistenly linear with a trend of 0.165 +/- 0.014 °C/decade. As for variability, you need to calculate the standard deviation of the residuals and use the standard 2*sigma criterion (equivalent to the 95% confidence level). Doing this will make apparent that nothing has changed up to now (2008), all the data points are within the +/- 2*sigma interval. Also, the last decade is nowhere near an anomalous deviation from the trend. Before claiming that we are in period of cooling or even flat temperatures we need to wait until the anomaly drops consistenly outside the statistical significance range. Using the same data and range as before I found a natural variability (2*sigma criterion) of about +/- 0.2 °C. It's worth to notice that even using smaller intervals down to the last decade sigma remains unchanged and again all the points are within +/-2*sigma, including those commonly considered extremes.
127860. Philippe Chantreau at 17:55 PM on 15 July 2009
        Climate time lag
        Robbo says "declining sensitivity to greenhouse gases" That implies that climate sensitivity is selective and variable, quite an interesting concept. References?
127861. Robbo the Yobbo at 14:50 PM on 15 July 2009
        Climate time lag
        damn it - I meant 0.08 degrees per decade
127862. Robbo the Yobbo at 14:02 PM on 15 July 2009
        Climate time lag
        This is just breaking – it appears that the underlying rate of warming between 1950 and 1997 was 0.1 degrees per decade. I would of (and have) used 1945 and 1998 – and get 0.08 degrees centigrade per decade. http://www.uwm.edu/~kswanson/publications/2008GL037022_all.pdf http://www.realclimate.org/index.php/archives/2009/07/warminginterrupted-much-ado-about-natural-variability/ Read carefully because Swanson supplies all necessary pre-digested rationalisations for global warmists. Although it is not new or startling science it is capitulation to the bleeding obvious. http://rogerpielkejr.blogspot.com/2009/07/two-decades-of-no-warming-consistent.html I am content to leave open the question of whether this is a longer term trend. The point is that 0.8 degrees per decade (and declining sensitivity to greenhouse gases) is not sufficient to warrant restricting the economic aspirations of billions of people. RealClimate states that this is not global cooling (at least not following the next decade or so) but natural variation - due to globally synchoised sea surface temperature changes triggering climte shifts over 20 to 30 years - on a warming trend. Has anyone argued that we can keep increasing carbon dioxide emissions. Certainly people like Bjorn Lomberg argue for an economically and technologically rational transition that doesn’t put millions of lives in the developing world at risk. And yes – stable democracy and a minimally regulated capitalism is the only way billions of people will emerge from poverty this century – although this would be more a policy than a science thread. So David, stop putting words in my mouth. If it is a contest between God and capitalism and aetheism and socialism - I am on the side of the angels.
127863. David Horton at 12:43 PM on 15 July 2009
        Climate time lag
        I guess all of this stuff on CRF and the like is what some people might think is the sophisticated end of the denialism spectrum. But there is nothing sophisticated about it. No one has ever imagined that the climate didn't change in the past, nor that there are other inputs into global warming apart from greenhouse gases, nor that the climate hasn't exhibited fluctuations over the past 150 years, or even the last 30 years, as a result of some of those inputs. But to be rabbiting on, at such length, about these minor matters, while the great big CO2 elephant in the room keeps trumpeting for attention, is a sign of the same old denialism that is based on an unshakeable ideology that either (or both), humans can't affect a god-given home; or unfettered capitalism based on an ever increasing dependence on burning fossil fuels is the only way to conduct human affairs.
127864. drewtoby at 10:48 AM on 15 July 2009
        Does Urban Heat Island effect add to the global warming trend?
        global warming is caused by bad gas emmitions, not artificial heating of a area. to fight global warming i think every one needs to make green choises. i have a site that tells people about reel mowers and the positive effects. if you are interested here is my link: greenmowers.org
127865. Alliecat at 10:18 AM on 15 July 2009
        The CO2/Temperature correlation over the 20th Century
        re #72: There's a thorough demolition of the "Due Diligence" (hah!) report at tamino's blog (see http://tamino.wordpress.com/2009/06/26/embarrassing-questions/ )
127866. shawnhet at 08:39 AM on 15 July 2009
        Climate time lag
        Chris, I don't really feel there is much to add here, Erlykin et al. agree that there is a correlation with the solar cycle and even provide a mechanism for what might be causing this. This is not something people typically do when they feel that the correlation is non-existent (which is what you were originally arguing). The ISCCP's recent data is somewhat controversial in this context, as I'm sure you know. As I already mentioned above, the issue about CRF-clouds is still in doubt. I know the Erlykin et al. paper disputes such a connection, but there are others that support it. http://rspa.royalsocietypublishing.org/content/464/2098/2575.abstract You seem to think that the papers that you agree with are the final word on the matter. "4. General point: You suggest that "Just because you disagree with Svensmark and Shaviv doesn't mean that they don't make logical arguments (even on their blogs)." But again that misses the point. I don't particularly disagree with what Shaviv and Svensmark say in their peer-reviewed scientific publications.. I disagree with the misrepresentational advocacy and false arguments on their websites (and Svensmark dismal book for that matter). I gave a couple of examples in relation to the Shaviv web site you urled (see my post #50)…the Svensmark web report I urled in post #50 is dripping with false "arguments". That's what I disagree with shawnet – rubbish on dodgy websites created to misrepresent the science." The fact is that you claimed that the arguments were illogical when they aren't, you just don't agree with them. The fact that you don't agree with them doesn't make them rubbish or whatever. "5. Another general point. There's lots of evidence of solar contributions to changes in climate in the past. It so happens that there has been little secular change in the solar outputs since 1958 (when these parameters started to me assessed in great detail), and the very marked warming of the past 30-odd years almost certainly has a negligible contribution from solar changes (despite the unsupported assertions on the dreary website you linked to in an earlier post). The solar contributions to climate changes in the past can generally be understood in relation to solar irradiance changes. Since the CRF changes generally correlate strongly with the solar irradiance changes (outwith Forbush events and the like), it’s easy for scurrilous "arguments" for solar irradiance chamges to be interpreted in terms of CRF changes (Svensmark does this on his website I urled)." The fact is, that CRF does not change in lockstep with solar irradiance(in fact solar irradiance doesn't change that much at all). Thus, when climate events follow changes in the CRF as they seem to have done historically that is good evidence of a CRF influence on climate. Given that such a relationship exists over the long term, it is logical to use that to inform our interpretation of short term events. No one said clouds had to be simple to understand. BTW, I'm not sure if you saw this above, but I am curious about the interpretation of the Krisjannson paper you referenced earlier. As I believe I said previously, Krisjannson found what appear to me to be some pretty good correlations btw CRF and CC, but concluded that there was no such correlation. Cheers, :)
127867. Robbo the Yobbo at 07:50 AM on 15 July 2009
        Climate time lag
        G'day, The PDO certainly has a correlation with global surface temperature. A cool mode to 1975 and a warm mode to 1998. The biological and physical chemical indications are that the PDO switched to a cool mode post 1999. The parallel with surface temperature is unmistakable. Although, I think it is a mistake to assume that the PDO is a cause of climate change rather than a co-variant. The PDO is associated with decadal modulation of ENSO. More intense and frequent El Niño in a warm mode and more intense and frequent La Niña in a cool mode. This suggests one mechanism for planetary warming and cooling. There are a couple of questions. Is the PDO real? It is certainly clearly evident in the sea surface temperature record in the latter half of last century. Before that – the available data all has wide margins of error. I think the most compelling argument for a natural origin is that is does seem to have conclusively switched to a cool mode. The cause of the PDO is deeply uncertain. The physical systems involved suggest that increases and decreases in shortwave radiation hitting the ocean surface heating could be the underlying cause if this varies on multi-decadal timescales. The ISCCP cloud cover record suggests that this is a possibility – although the period of record (and perhaps uncertainties in the data) are insufficient to be anywhere near conclusive. The periodicity of the PDO is certainly not explained by the 11 year solar cycle. The 22 year polar reversal cycle a more likely candidate. See this 1995 paper for an explanation. The 22 year cycle gives 11 years of peak magnetic activity and 11 years of subdued magnetic activity. Could this interact with the physical systems of the planet to produce changes with a 25 year harmonic? Interesting speculation. http://dawn.ucla.edu/personnel/russell/papers/731/731index.htm The heliospheric magnetic variation may be more important or the solar modulation parameter of Usoskin. These certainly did not peak in 1960 along with sunspot number. This all remains speculative and arguments about the non correlation of a particular metric misses the point. If the theory doesn’t fit the data – the theory needs revision. The current global warming debate finds certainty where there is precious little to be had. We talk about 50 years or less of reasonably accurate data on a few metric as if that could provide proof in such a complex system. We talk about reconstructions going back millions of years as if there is a precision in the results sufficient to mirror the precision of instrumental results. We have forgotten all of our ‘science of science’ and instead it is in the hands of advocates.
127868. chris at 06:24 AM on 15 July 2009
        Climate time lag
        shawnet, yes, O.K., but the preprint you've described is another example of evidence in the scientific literature (to be!) of a lack of significant causal relationship between the cosmic ray flux (CRF) variation and cloud/temperature variation. I'm happy that you're directing our attention to the science rather than the dreadful website you linked to earlier on this thread. We can look at the preprint in more detail... downloadable from here: http://arxiv.org/abs/0906.4442 [A.D.Erlykin, G.Gyalai, K.Kudela, T.Sloan, A.W.Wolfendale On the correlation between cosmic ray intensity and cloud cover] The following points can be made: 1.There isn't a robust correlation between the solar cycle and the ISCCP cloud data. That can be confirmed by inspection of the ISCCP data I linked to above (see post #55). There is a correlation between the solar cycle and low level clouds through cycle 22, after which this correlation breaks down. Erlykin describe a moderate correlation coefficient (0.54) between solar cycle and low clouds through cycle 22 but this is only 0.24 through cycle 23 which is an very low correlation. Erlykin present data up to 2005. If this is extended to 2008 (see ISCCP web site link in post #55), the correlation is even worse. 2. Erlykin address "the correlation between cosmic ray intensity and cloud cover". The conclusion is that this correlation is moderate in cycle 22, but effectively discorrelated in solar cycle 23. In all cases any correlation is shown not to be causal. In other words (according to Erlykin), any apparent correlation is not the result of a CRF effect on clouds but is (if the correlation is true) due to the solar irradiance changes through the solar cycle. e.g. Erlykin et al conclude:

        "the reduction of CR intensity coincident with the reduction of LCC is therefore by no means evidence of the causal connection between these two phenomena – they correlate with each other due to their common origin - the change of solar irradiance at the Earth."

        and

        "We argue that the positive correlation of CR and LCC found in Svensmark and Friis-Christensen, (1997) and Palle Bago and Butler, (2000) is not evidence for a causal connection between them, but the consequence of a parallel influence of the common source - the solar activity on CR from one side and CC the other."

        3. Erlykin make a number of analyses of the possible causal contribution of CRF on low level cloud cover during solar cycle 22 (where there is a bit of a correlation with the solar cycle). Within a model where CRF are responsible for a fraction of the low level cloud change and CRF is the only cause of this fraction (the Shaviv model; Svensmark might or might not agree) they can determine a value of the fraction of low level clouds caused by changes in CRF. This is close to zero:

        "This shows that the most likely fraction of LCC (low cloud cover) connected with CR (cosmic rays), which can be derived from expression (3), does not exceed 2% around X = 1."

        and so on…the data and analyses taken at fasce value strongly support the conclusion that clouds, whether low level or whatever, do not respond signifcantly to changes in the CRF, and any apparent corelations observed (in solar cycle 22) are not causal. The likely source of any apparent correlations is the efects of solar irradiance changes on atmospheric and surface temperature. That seems entirely consistent with a vast amount of other science in the scientific literature. 4. General point: You suggest that "Just because you disagree with Svensmark and Shaviv doesn't mean that they don't make logical arguments (even on their blogs)." But again that misses the point. I don't particularly disagree with what Shaviv and Svensmark say in their peer-reviewed scientific publications.. I disagree with the misrepresentational advocacy and false arguments on their websites (and Svensmark dismal book for that matter). I gave a couple of examples in relation to the Shaviv web site you urled (see my post #50)…the Svensmark web report I urled in post #50 is dripping with false "arguments". That's what I disagree with shawnet – rubbish on dodgy websites created to misrepresent the science. 5. Another general point. There's lots of evidence of solar contributions to changes in climate in the past. It so happens that there has been little secular change in the solar outputs since 1958 (when these parameters started to me assessed in great detail), and the very marked warming of the past 30-odd years almost certainly has a negligible contribution from solar changes (despite the unsupported assertions on the dreary website you linked to in an earlier post). The solar contributions to climate changes in the past can generally be understood in relation to solar irradiance changes. Since the CRF changes generally correlate strongly with the solar irradiance changes (outwith Forbush events and the like), it’s easy for scurrilous "arguments" for solar irradiance chamges to be interpreted in terms of CRF changes (Svensmark does this on his website I urled).
127869. shawnhet at 02:01 AM on 15 July 2009
        Climate time lag
        Chris, #1. According to the following preprint by Erlykin, SLoane & Wolfendale, there is a correlation btw the solar cycle and CC. They propose a different mechanism than cosmic rays to account for it. "We advocate a scenario for the ***origin of correlations between CR and LCC***, based on the parallel influence of solar activity. The solar irradiance rises with the sunspot number in the middle of the solar cycle. The radiation is strongest in the tropics and subtropics. Though the relative rise of the irradiance is small, and only about 0.1%, it causes a rise of the mean surface temperature and an increase of the vertical convection flows of the heated air. The subsequent change in supersaturation of the air at different heights can cause the changes in LCC and MCC. Warm air from below 3 km rising to greater heights will cause the LCC to fall and MCC to rise. By this way the rise of convection flows leads to a **considerable magnification (to ∼2%) of the effect of enhanced solar irradiance**. Formulating briefly, one can say that in the maxima of the solar cycles the updraft becomes stronger and this effect is strongest in the tropics and subtropics, as well as in the southern latitude bands where there is the largest fraction of area covered by the oceans. It is well known that the variations of solar activity are followed by the variations of CR intensity at Earth; the reduction of CR intensity coincident with the reduction of LCC is therefore by no means evidence of the causal connection between these two phenomena - they correlate with each other due to their common origin - the change of solar irradiance at the Earth." ON THE CORRELATION BETWEEN COSMIC RAY INTENSITY AND CLOUD COVER 1 A.D.Erlykin(1,2), G.Gyalai(3), K.Kudela(3), T.Sloan(4), A.W.Wolfendale(2) pre-print #2. I don't really dispute the issue that CRF variations have had relatively minimal impact on the warming from say 1970-2000. It is pretty clear that the two major portions of them were most likely anthropogenic changes and the PDO(in no particular order). #3. IMO, any discussion of CRF-cloudiness link that ignores the strong long-term correlations is ignoring the evidence(for instance see above). IMO, the best evidence on CRF shows that there is a nonlinear interaction of some sort btw climate and CRF such that high CRF periods are correlated with cool climates. Smaller, shorted term changes in CRF (like recent ones) seem to have much less impact than the long term studies would suggest. #4. Just because you disagree with Svensmark and Shaviv doesn't mean that they don't make logical arguments(even on their blogs). The fact is, we don't have enough information to answer the CRF question definitively. We can't really tell yet what impact (if any) CRF changes have on clouds. Cheers, :)
127870. PeterPan at 18:26 PM on 14 July 2009
        Climate time lag
        Loads of thanks! I've been trying to understand the warming in the pipeline for some time without success. Thanks to this article I think I get the picture. It also helps me to understand the "simple model" article at RC (http://www.realclimate.org/index.php/archives/2007/04/learning-from-a-simple-model/). Thanks a lot!!!
127871. chris at 17:10 PM on 14 July 2009
        Climate time lag
        re #51 ONE: Solar cycle – cloud response There isn't a robust relationship between the solar cycle and cloud response. There was an apparent relationship within solar cycle 22 (which is what Wolfendale and Sloan were addressing), but this relationship completely breaks down in the following cycle, and the recalibration of the ISCCP data (partly in response to artefacts in the satellite viewing geometry over which there still seems to be some concern; e.g. [*]) makes this apparent correlation smaller still [**]. You can see the mismatch between the cloud data and the solar cycle over the full record by sampling the ISCCP data from its repository: http://isccp.giss.nasa.gov/index.html (see Part 7 for low, medium and high level clouds) The bit of the abstract you quoted from the Wolfendale Sloan paper doesn't mean that 23% of low level cloud – solar cycle relationship (which is only apparent for solar cycle 22 and has been recalibrated anyway!) is due to the CRF, nor that the clouds necessarily respond in a cyclical manner in response to the solar cycle. It just means that the statistical relationship between the solar trend through cycle 22 and the cloud trend through cycle 22 has less than 23% that could "belong" to any CRF component. The meaning is clearer if one quotes from the body of the paper:

        "From this it is deduced that less than 23% of the distribution, at the 95% confidence level, belongs to the part correlated with the CR modulation and more than 77% belongs to the other sources correlated to solar activity but not directly to the change in ionization rate. These limits are incompatible with a large part of the change in the LCC during solar cycle 22 being produced by a change in ionization and so they do not corroborate the hypothesis of such a change proposed in [1, 2]. The correlation seen in figures 1 and 2, if real, must be due to an effect, other than ionization, which is correlated with solar activity."

        TWO: Web site advocacy vs scientific literature I said:

        "Shaviv and Svensmark don't publish this sort of stuff in the peer-reviewed scientic literature since you generally have to present scientifically and logically robust arguments with proper data, in science journals. Obviously one can say whatever one likes on one's website."

        you said:

        "While it is true that this particular response wasn't published, this leaves the impression that they can't publish their ideas."

        You've misunderstood my point I think. This is that there is a huge disconnect between the fairly standard stuff these scientists publish in the scientific literature and the overblown advocacy that appears on their websites - these sites are certainly not designed as scientific information resources! They're highly misleading of the science in the area of solar contributions in general which has a rich and extensive scientific literature. That sort of misrepresentational advocacy isn't found in the scientific literature since the latter has processes that promote standards of scientific rigour ('though some rubbish gets through ocasionally!). So if one looks at the scientific papers of these scientists they're generally straightforward science without the dreary one-eyed advocacy that completely misrepresents the subject on their web sites. They certainly do publish their data/interpretations/ideas in the scientific literature. The J. Phys. Chem. paper of Svensmark's, for example, is a nice solid bit of physical chemistry. Their web sites are something else! That's the point I was making. Anyone resorting to the dreadful web pages under discussion will be hopelessly misinformed. THREE: Harrison and Stephenson (2007) Yes, it's possible there is a Forbush-diffuse fraction response in their data. It's not that convincing. There seems to be a strong drop in the DF 10 days before the Furbush event in both data sets and in the Jersey data, this is the strongest drop in the record which might lend one to consider whether the analysis is robust in terms of a CRF diffuse fraction coincidence… It's telling that in the Hadley Centre technical report #62 (HCTN 62) "The influence of solar changes on the earth's climate" of which Harrison is one of the three authors, the possibility of a CRF – cloud link (specifically: "Solar modulation of global clouds, through production of CNN from cosmic ray ionisation") is descibed as being "Contentious", in their categorization of probabilities of various elements of the possible solar – climate relationships. That seems a pretty succinct summing up. http://www.metoffice.gov.uk/publications/HCTN/index.html FOUR: General point. I'm pretty relaxed about whether there is a CRF-cloud link (quite possibly yes) and a CRF-temperature link (evidence suggests this is unlikely to be significant). Unfortunately the pretty straightforward data in the scientific literature is being grossly misrepresented by a tiny number of advocates to massively overplay the significance of the evidence as it stands in the scientific literature. It's pretty obvious that there can have been no significant contribution of any CRF change to the very large warming of the last 30-odd years since there has been essentially no secular trend in this metric during the period since 1958 (if anything a slight cooling contribution). It's difficult to escape that non-correlation….. ------------------------------------------------------ [*] A. T. Evan et al (2007) Arguments against a physical long-term trend in global ISCCP cloud amounts Geophys. Res. Lett. 34, L04701 abstract: The International Satellite Cloud Climatology Project (ISCCP) multi-decadal record of cloudiness exhibits a well-known global decrease in cloud amounts. This downward trend has recently been used to suggest widespread increases in surface solar heating, decreases in planetary albedo, and deficiencies in global climate models. 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.” [**] E. Pallé et al (2009) Interannual variations in Earth's reflectance 1999–2007 J. Geophys. Res. 114, D00D03 Abstract: The overall reflectance of sunlight from Earth is a fundamental parameter for climate studies. Recently, measurements of earthshine were used to find large decadal variability in Earth's reflectance of sunlight. However, the results did not seem consistent with contemporaneous independent albedo measurements from the low Earth orbit satellite, Clouds and the Earth's Radiant Energy System (CERES), which showed a weak, opposing trend. Now more data for both are available, all sets have been either reanalyzed (earthshine) or recalibrated (CERES), and they present consistent results. Albedo data are also available from the recently released International Satellite Cloud Climatology Project flux data (FD) product. Earthshine and FD analyses show contemporaneous and climatologically significant increases in the Earth's reflectance from the outset of our earthshine measurements beginning in late 1998 roughly until mid-2000. After that and to date, all three show a roughly constant terrestrial albedo, except for the FD data in the most recent years. Using satellite cloud data and Earth reflectance models, we also show that the decadal-scale changes in Earth's reflectance measured by earthshine are reliable and are caused by changes in the properties of clouds rather than any spurious signal, such as changes in the Sun-Earth-Moon geometry.
127872. Adlai Gavins at 14:53 PM on 14 July 2009
        The CO2/Temperature correlation over the 20th Century
        Senator Steve Fielding has posted his 3 questions to Climate Change Minister Penny Wong, her answers and his assessment. http://www.stevefielding.com.au/climate_change/ Any comments with regards to the science and arguments of Senator Fielding and the Carter/Evans/Franks/Kinimonth's Due Diligence assessment? Thanks.
127873. Robbo the Yobbo at 10:36 AM on 14 July 2009
        Climate time lag
        Actually, I was confused - the graph shows annual change in sea level and not mean sea level. It shows the rate of change declining declining since 1998 - there should be a law against people who torture data. Cheers Robbo
127874. Robbo the Yobbo at 10:14 AM on 14 July 2009
        Climate time lag
        Do cloud affect climate? Without a doubt. The ISCCP-FD reconstruction shows decling cloud cover to 1998 and increasing cloud cover since. This can be seen on Professor Ole Humlum's website. A great source for up to date climate data. http://www.climate4you.com/ClimateAndClouds.htm In the climatically important equatorial zone. Both high and low cloud cover decreased to 1998 and have increased since then explaining some of the global heat trends - particularly the perplexing mystery of the lost heat since 1998. I also note an updated sea level graph on the ocean page graph showing a decline in annual sea level since 1998. And before anyone quibbles - check the ocean heat storage in Figure 2 above. Now I am confused - it is based on the (gold standard)University of Colorado data but looks entirely different because it averages the 10 day readings over a year. I am now wondering whether this has something to do with the hydrological cycle. A global increase in water vapour and rainfall - driven by higher sea surface temperature after the mid 1970's. A problem for Ron (lateron - for those unfamiliar with Australian colloquialism - Blind Freddy has offered to lead a seminar). Ah complexity - thy name is climate science. Is there a connection of cloud with the 11 year solar cycle? All I know is that clouds have changed and that there is a long term correlation of cosmogenic isotopes and global temperature. If clouds change back around 2024, I will be surer of a cloud cover and a cosmic connection to the Pacific Decadal Oscillation and multi-decadal ENSO modulation. I am pretty sure there are 50, 1500 and 100,000 year (approximately) climate cycles.
127875. Robbo the Yobbo at 06:28 AM on 14 July 2009
        Climate time lag
        re 47 Most of the ocean mass increase occurred in 2004/2005. What I said was let's assume that is real and not some artifact of JASON altimetry.
127876. shawnhet at 06:10 AM on 14 July 2009
        Climate time lag
        Chris, Thank you for the additional detail on the Svensmark paper. "A rather fatal flaw with the cosmic ray flux (CRF) cloud/climate hypothesis is that the straightforward natural experiments in which the CRF varies by up to 20% through the 11 year solar cycle, or undergoes dramatic short lived reductions again up to around 20% in so-called Forbush events, shows no significant cloud response whatsoever….." I don't know why you keep making this statement, but it is inaccurate. From Sloan & Wolfendale 2008 "we estimate that less than 23%, at the 95% confidence level, of *the 11 year cycle change in the globally averaged cloud cover observed in solar cycle 22* is due to the change in the rate of ionization from the solar modulation of cosmic rays." http://www.iop.org/EJ/abstract/1748-9326/3/2/024001/ From the above, we can clearly see that there is an 11 year change in globally averaged cloud cover that (more or less) follows the solar cycle. To keep asserting the contrary is to ignore the evidence. Likewise, here is some evidence that cloud cover is affected by Forbush events Harrison R.G. & D.B. Stephenson, Proc. Roy. Soc. A, doi:10.1098/rspa.2005.1628, 2006 I think that you seem to be misunderstanding the state of the science here. "Shaviv and Svensmark don't publish this sort of stuff in the peer-reviewed scientic literature since you generally have to present scientifically and logically robust arguments with proper data, in science journals. Obviously one can say whatever one likes on one's website." While it is true that this particular response wasn't published, this leaves the impression that they can't publish their ideas. Both gentlemen's papers have been pretty widely cited, and while the overall theory is still debatable, the evidence for it is **substantially** better than you are attempting to present it as. That doesn't mean that it will turn out to be an accurate theory, but the idea that they cannot make logical arguments is not true. Thank you for the Erlykin paper, that is interesting stuff. BTW, how familiar are you with Krisjannson's paper, I can't figure out how he derived his conclusions. If you look at his actual graphs, they appear to give quite high correlation btw CRF and the cloud measurements, but he somehow comes to the conclusion that they are not closely correlated at all. Cheers, :)
127877. chris at 05:17 AM on 14 July 2009
        The CO2/Temperature correlation over the 20th Century
        re #70 Not really Mizimi. Occams razor doesn't say anything about the acceptance of the simplest possible explanation. A better phrasing of Occam's razor is: "don't multiply causes unnecessarily". When applied to scientific enquiry we're still left with the question of evidence, and this is the gold standard within which Occam's razor is a useful adjunct. So we don't reject cosmic ray flux or vague tectonic contributions to the major late 20th century and contemporary warming merely because these are unnecessary multiplications of causes. We reject them because they don't have a basis in evidence, and the abundant evidence that exists doesn't support these as significant causal explanations. Of course that doeesn't mean that the cosmic ray flux and tectonic events shouldn't be studied. Far from it, and many scientists study the CRF and tectonic processes. The scientific literature has abundant publications on these interesting subjects. However scientists don't pretend that these have significant evidence towards causality in relation to contemporary global warming, and therefore don't attempt to "multiply causes unnecesarily". That's the role of the unscrupulous and misguided (and their dodgy websites!). Once one understand the handy use of Occam's razor within the scientific philosophy of empirical evidence interpreted within sound theoretical understanding, we can stop playing semantic games and ignore tedious and trite leading questions....
127878. Mizimi at 04:53 AM on 14 July 2009
        The CO2/Temperature correlation over the 20th Century
        66#....In the scientific method, Occam's razor, or parsimony, is an epistemological, metaphysical, or heuristic preference, not an irrefutable principle of logic, and certainly not a scientific result. As a logical principle, Occam's razor would demand that scientists accept the simplest possible theoretical explanation for existing data. However, science has shown repeatedly that future data often supports more complex theories than existing data. Science tends to prefer the simplest explanation that is consistent with the data available at a given time, but history shows that these simplest explanations often yield to complexities as new data become available. (Wikipedia) Should we just dust our hands and say since AGW is the simplest hypothesis let's look no further? Don't let's explore other possibilities..even if they turn out to be dead ends? Surely scientific method includes probing and proving both negatives and positives? Has our research into climate produced nothing at all that detracts from the simple CO2 model? Are we that confident GCM's include all that is necessary to project both forward and backward with a high degree of accuracy? If so, why do they fail to do so?
127879. chris at 03:15 AM on 14 July 2009
        Climate time lag
        A rather fatal flaw with the cosmic ray flux (CRF) cloud/climate hypothesis is that the straightforward natural experiments in which the CRF varies by up to 20% through the 11 year solar cycle, or undergoes dramatic short lived reductions again up to around 20% in so-called Forbush events, shows no significant cloud response whatsoever…..and yet some proponents of this hypothesis claim a substantial CRF role in the very marked warming of the last 30-odd years, even though the secular trend in the CRF has been close to zero since around 1958 (slightly in the "cooling direction" if anything through the early 21st century). If massive changes in the CRF produce an undetectale responses, how can virtually zero long term change (or changes in the wrong direction) produce very large effects? The way that the CRF'ers attempt to wriggle free of this problem says quite a lot about the unfortunate disconnect between science in the scientific literature and presentations by a small number of advocates on webstes. On this thread Robbo (post #19) has attempted to deal with the problem ("fatal flaw") by questioning whether CRF- induced cloud nucleation should be instantaneous and whether there should be a link to the 11 year solar cycle. Perhaps there is a long lag between nucleation and cloud formation? Shawnet (post #18) suggests in response to this problem: " I would not be so quick to accept chris's assertion that there is no link btw CRF and clouds" (which I never asserted at all, btw), and refers us to a very odd website by Shaviv. Let's look at both of these: ONE: Robbo and his questioning of fast cloud response to changes in CRF and a link to the solar cycle. Is there a large lag? Let's see what the the CRF-climate advocates think. We can assume that their websites provide the most salient representation of their views untainted by the rigours of peer review. Svensmark: www.spacecenter.dk/publications/scientific-report.../Scient_No._3.pdf Svensmark clearly thinks there should be a negligible lag between the change in the CRF and the cloud/temperature response. He (and Friis-Christensen) make great play in purporting to show a very close temperature-solar cycle link. There's nothing controversial about that of course; it's expected that the solar cycle variation should give a contribution to temperature variation near 0.1 oC max-min-max. Of course it doesn't have anything necessary to do with the CRF, and is fully explainable by changes solar irradiance as indicated by a large body of solar science. No lag. Shaviv: http://www.sciencebits.com/SloanAndWolfendale No lag either. In fact his main criticism of the Sloan Wolfenden paper on the lack of correlation of CRF changes in Forbush events and the cloud response (see TWO below – this is the web page that Shawnet directed us to) is that they use weekly and monthly averages of cloud cover. According to Shaviv the cloud response to the large changes in the CRF is fast and one needs to use daily averages of cloud cover to capture the response. He says "To see effects, one therefore needs to use daily averages of the cloud cover". No lag. So Robbie's questions are addressed very succinctly by the two major proponents of the CRF-climate notion. There isn't a lag between CRF changes and cloud/temperature response – the response should follow the solar cycle. Except it doesn't. It's worth pointing out that Shaviv's stipulation that one needs to address fast (daily averaged) cloud responses to CRF changes in Forbush events has been addressed in a recent detailed analysis of the fast (daily averaged) cloud response to CRF changes in Forbush events [***]. The result:

        "The overall conclusion, built on a series of independent statistical tests, is that no clear cosmic ray signal associated with Forbush decrease events is found in highly susceptible marine low clouds over the southern hemisphere oceans."

        TWO: Shawnet refers us to the Shaviv web site as an "explanation" why he "wouldn't be so quick to accept chris's assertion…" (i.e. my "fatal flaw" point in my first paragraph). In fact Shaviv doesn't address my point but attempts to counter a different one rasied by Wolfendale – Sloan that any slight cloud response to the solar cycle actually lead the CRF changes and therefore the causal element of the CRF-cloud hypothesis is incompatible with the very detailed empirical evidence of the last 60 years. Even 'though this is a different point to mine, let's look at this anyway. Shaviv makes a bogus argument in attempting to explain away the Wolfendale - Sloan problem. He asserts that the phase problem (cloud changes lead CRF changes) arises from the fact that the CRF isn't the only contribution to clouds and that the temperature response to the solar cycle drives a cloud response that shifts the phase of the solar cycle – cloud "couple". He uses some dubious numerology to calculate a cloud response to solar cycle irradiance changes based on the statement that: " We also know that the global temperature changes by about 0.1°C between solar maximum and solar minimum". That sounds like what I said above viz "it's expected that the solar cycle variation should give a contribution to temperature variation near 0.1 oC max-min-max."…. …except it isn't. Shaviv's assertion simply isn't true as anyone that inspects the earth's temperature evolution over the last 60 years could easily see for themselves (e.g. look at Svensmark's Figure 2 on his website I urled above). While the contribution of the solar cycle is around 0.1 oC, this is hidden beneath noise from internal variation in the earths temperature evolution, long term warming trends and so on. If we're going to compare empirical real world data on solar cycle-cloud responses, and are purporting a temperature – cloud contribution, we have to use the real temperature and not a theoretical idealised solar cycle temperature expectation. Likewise, since Shaviv is proposing a solar irradiance-induced cloud response that briefly leads the main CRF-cloud response, we need to consider cloud response during the early part of the solar cycle change. If, for example, the solar cycle max to min irradiance change results in a total change over around 5.5 years of -0.1 oC, Shaviv is proposing that the clouds are responding to an (idealised) temperature change near 0.018 to 0.036 oC (that isn't actually manifest in reality since these tiny contributions are completely swamped by internal variations in the climate system). Shaviv and Svensmark don't publish this sort of stuff in the peer-reviewed scientic literature since you generally have to present scientifically and logically robust arguments with proper data, in science journals. Obviously one can say whatever one likes on one's website. n.b. Those interested in the science on this topic should know that Wolfendale – Sloan have recently published a more detailed confirmation of the lack of correlation of CRF – temperature effects in the 20th century and which reinforces the expectation that any solar – climate relationships are likely due to solar irradiance variation rather than CRF changes. [*****] [***} Kristjansson JE et al. (2008) Cosmic rays, cloud condensation nuclei and clouds - a reassessment using MODIS data Atmos. Chem. Phys. 8, 7373-7387 [*****]Erlykin AD et al. (2009) Solar activity and the mean global temperature Environ. Res. Lett. 4, art # 014006 (see preceding post #49 for abstracts)
127880. chris at 03:08 AM on 14 July 2009
        Climate time lag
        re #17 Philippe - not sure. A couple of recent papers suggest: (1) that the change rate of ionization in the lower atmosphere through the maximum variation in CRF (solar cycle max to min) is of the order of 3% [*]... and (ii) that when the largest CRF variations (Forbush events) are analyzed in detail there is a small (but statisticaly insignificant) effect on cloud droplet size (not sure what this means with respect to the CRF-cloud hyothesis), but that the effect on cloud optical depth is in the wrong direction to that expected from the CRF cloud link [**]. So the real world still refuses to conform to the CRF-cloud-temperature hypothesis... [*]Erlykin AD et al. (2009) Solar activity and the mean global temperature Environ. Res. Lett. 4, art # 014006 Abstract: The variation with time from 1956 to 2002 of the globally averaged rate of ionization produced by cosmic rays in the atmosphere is deduced and shown to have a cyclic component of period roughly twice the 11 year solar cycle period. Long term variations in the global average surface temperature as a function of time since 1956 are found to have a similar cyclic component. The cyclic variations are also observed in the solar irradiance and in the mean daily sun spot number. The cyclic variation in the cosmic ray rate is observed to be delayed by 2-4 years relative to the temperature, the solar irradiance and daily sun spot variations suggesting that the origin of the correlation is more likely to be direct solar activity than cosmic rays. Assuming that the correlation is caused by such solar activity, we deduce that the maximum recent increase in the mean surface temperature of the Earth which can be ascribed to this activity is less than or similar to 14% of the observed global warming. [***] Kristjansson JE et al. (2008) Cosmic rays, cloud condensation nuclei and clouds - a reassessment using MODIS data Atmos. Chem. Phys. 8, 7373-7387 Abstract: The response of clouds to sudden decreases in the flux of galactic cosmic rays (GCR) - Forbush decrease events - has been investigated using cloud products from the space-borne MODIS instrument, which has been in operation since 2000. By focusing on pristine Southern Hemisphere ocean regions we examine areas where we believe that a cosmic ray signal should be easier to detect than elsewhere. While previous studies have mainly considered cloud cover, the high spatial and spectral resolution of MODIS allows for a more thorough study of microphysical parameters such as cloud droplet size, cloud water content and cloud optical depth, in addition to cloud cover. Averaging the results from the 22 Forbush decrease events that were considered, no statistically significant correlations were found between any of the four cloud parameters and GCR, when autocorrelations were taken into account. Splitting the area of study into six domains, all of them have a negative correlation between GCR and cloud droplet size, in agreement with a cosmic ray - cloud coupling, but in only one of the domains (eastern Atlantic Ocean) was the correlation statistically significant. Conversely, cloud optical depth is mostly negatively correlated with GCR, and in the eastern Atlantic Ocean domain that correlation is statistically significant. For cloud cover and liquid water path, the correlations with GCR are weaker, with large variations between the different domains. When only the six Forbush decrease events with the largest amplitude (more than 10% decrease) were studied, the correlations fit the hypothesis slightly better, with 16 out of 24 correlations having the expected sign, although many of the correlations are quite weak. Introducing a time lag of a few days for clouds to respond to the cosmic ray signal the correlations tend to become weaker and even to change sign.
127881. chris at 02:52 AM on 14 July 2009
        Climate time lag
        re #15 Shawnet, I can't find a freely downloadable version of the paper. Here's the relevant section from the experimental methods section of the J. Phys. Chem. paper I referred to in post #13:

        "Two series of measurements were performed: the first one (I) with SO2 set to 4 ppb and O3 to 23 ppb and a second series (II) with SO2 set to 30 ppb and O3 to 68 ppb. Atmospheric levels of SO2 range from 20 ppt in the marine surface layer to 1.5 ppb in polluted areas, and O3 concentrations lie between 20 and >200 ppb."

        The ozone levels are realistic. The SO2 levels are very high, especially considering that in the preindustrial natural world, SO2 levels are more likely to be the 20 parts per trillion (marine surface layer) than the 1.5 parts per billion (heavily polluted areas). After all "heavily polluted areas" only exist (outwith volcanic eruption scenarios) in the modern era within which independent evidence rather negates a significant climate contribution from the CRF flux. Natural (non-pollutant) levels of SO2 are between 20-230 ppt according to Seinfeld J.H, Pandis S.N Atmospheric chemistry and physics (1988). I should say that the large 4000 to 30000 parts per trillion concentrations of SO2 used by Svensmark (rather than 20 to 230 ppt natural levels) is not necessarily a major flaw in Svensmark's study, since the particle count is limited by the sensitivity of the particle detector used, and doesn't necessarily mean that lower levels of SO2 don't produce gamma-ray-inducd particles – they just couldn't be detected with the set up used (according to Svensmark's paper). Incidentally,the sentences you pasted from the site you urled seem rather defensive to me! I haven't come across any papers in which the solar-climate link is "disregarded". Solar contributions are always considered - an example is the Hansen et al (2005) paper from which John Cook took the figure on TOA Net radiation. Inspection of the paper indicates that best estimates for all known and quantitated forcings were included in the analysis, solar included. That's always the case. I might say a bit more about the dreary website you urled if I have time later…..
127882. Thumb at 00:31 AM on 14 July 2009
        Climate time lag
        "I keep referencing peer reviewed literature, highly experienced and respectable scientists, the Hadley Centre, CERN etc and you keep saying - nah it just isn't so - you're an idiot right ring ideologue." But as you said in #27: "Let’s neglect the unlikely 6 month rise..." So what good is referencing peer reviewed literature if you can cavalierly discount inconvenient information? Maybe that's why you think we think "you're an idiot right ring ideologue."
127883. Riccardo at 22:19 PM on 13 July 2009
        Climate time lag
        Robbo, you definitely misquoted or misunderstood my comment. I've never said you're an idiot nor a right wing ideologist. I didn't even said that the GCR-clouds connections is a hoax. I've just pointed out that the "theory" of GCR-induced global warming is not yet a theory and i'm sure you are well aware that a correlation does not make an hypothesis a theory. Assuming it's _the_ theory is simply ideological.
127884. Robbo the Yobbo at 20:05 PM on 13 July 2009
        Climate time lag
        Ricardo, I keep referencing peer reviewed literature, highly experienced and respectable scientists, the Hadley Centre, CERN etc and you keep saying - nah it just isn't so - you're an idiot right ring ideologue. Atmospheric temperature has declined since 1998 on every record bar the GISSTEMP – and that shows 1998 and 2005 (after a data rejig) as equal within the limits of error. An El Niño may form in the boreal summer but there are a couple of problems with this idea. It is first of all only a transfer of energy from the ocean to the atmosphere. The ocean will get cooler – it doesn’t change the total energy equation. Secondly, ENSO event frequency and intensity is statistically associated with the state of the Pacific Decadal Oscillation. A cool mode, over 20 to 30 years, is associated with more intense and more frequent La Niña and less frequent and less intense El Niño. A weak El Niño or neutral conditions is statistically probable in the current PDO cool mode. Ocean warming trends seem to be indistinguishable from zero (Leuliette 0.8mm/yr +/- 0.8, Willis -0.5mm/yr +/- 0.6, Loethe declining heat content, Cazanave – essentially zero). I expect that there is a 20 to 30 year cooling trend from the underlying cause of the blindingly obvious and related global multi decadal phenomenon. We shall see who has a theory.
127885. Riccardo at 17:23 PM on 13 July 2009
        Climate time lag
        Robbo, the point is that _you_ don't have a theory. And you'll never have one if pick up a selected set of contraddictory data uncritically. What is left is just a declaration of your ideology.
127886. thingadonta at 16:39 PM on 13 July 2009
        Climate time lag
        the last post should be "re:41" sorry
127887. thingadonta at 16:37 PM on 13 July 2009
        Climate time lag
        re:45 It is patently FALSE to say there is only one mechanism or line of evidence for warming-that of rising trace gas levels. The sun has also increased activity over scales of decades-centuries. Both changes are very small, it is a question of relative forcings, and which better correlates and explains, and their relative proportional effect. Even the IPCC guestimates the sun at around 7.5% contribution, down from ~20% from the 2004 report (which is the main issue of dispute). You sound very much like a 'majority-dominant conformist'-ie the common view that ~10% of data that doesnt fit into a dominant model or paradigm is irrelevant. This approach does not work within chaotic systems. Small 'irrelevancies' can have large-scale effects. To state that there is only one evidential 'mechanism' shows you colours; this summation is false. It is also pre-assuming the conclusion on relative forcings, and shows you are not really willing to look at all the evidence. 10% of data that doesnt fit within a 'dominant' model or paradigm does not necassarily only produce 10% of effect. This is especially the case in chaotic systems, and is part of the reason they are chaotic and unpredictable in the first place. Much the same modelling mistakes have been made by financial modellers in recent times. Note also: air T has not risen in at least 10 years, around 15 from a statistical viewpoint, irrepsective of El Nino, 1998. Yet you keep saying T is "rising". Which planet are you living on? Finally, rising c02 levels do not correlate with 2/4 step-like trends in earth T in the last 150 years (1940s-1970s, 2000s-2009), the sun's activity correlates with 3/4 (1890s-1940s, 1940s-1970s, 2000s-2009). So the sun correlates better than C02, (although the last is only a short period, so far). So which is, to use your words, "disproved". (Another word which shows you just don't get it).
127888. David Horton at 15:56 PM on 13 July 2009
        Climate time lag
        John, responses to these latest two posts ("Climate time lag" and "The CO2/Temperature correlation over the 20th Century") are sounding like a seminar at the Heritage Foundation. We have, it seems, every far-fetched, imaginary, evidence free, disproved, possible mechanism for rising temperature on this planet, except the one for which we have evidence - rising greenhouse gas levels. It would be good if you could cut through some of the nonsense.
127889. thingadonta at 14:39 PM on 13 July 2009
        Climate time lag
        I think your multiple postings of the same thing are ok, since if you say something loud enough and for long enough, people will begin to believe it- at least it works with saying a 1/10,000 part change in trace gases in the atmosphere has raised the earth's climate T by about one degree ....whilst similar changes in something so enormous as the sun is dismissed as "too tiny". And then there is the argument that the sun hasnt changed much since the mid 20th century,-imagine a bunch of human-global warmers running around between 1 and 3pm looking for a 'mechanism' to explain why the day continues to get warm after the sun peaks at noon.... Future generations will laugh. Human global warming is the 21st century version of Babylonian astrology...but in reverse, instead of movements in the heavens supposedly affecting peoples lives, now people's activities are affecting the 'heavens'...
127890. Robbo the Yobbo at 13:03 PM on 13 July 2009
        Climate time lag
        There is a wonderfull book on fisheries and climate cycles if anyone is interested. http://alexeylyubushin.narod.ru/Climate_Changes_and_Fish_Productivity.pdf Cheers
127891. Robbo the Yobbo at 12:16 PM on 13 July 2009
        Climate time lag
        The correlation between cosmogenic isotopes and global surface temperature over 1150 years is also an empirical reality - with the best correlation being with a 10 year lag. It implies a relationship between heliospheric magnetic intensity and global surface temperature. Do you have a different theory to explain the data? i.e correlation is not causality. What is then the cause of climate variation - and why isn't it included in the IPCC forcings? Apologies for posting the same thing three times - it seems to happen when the refresh button is pushed.
127892. Robbo the Yobbo at 11:57 AM on 13 July 2009
        Climate time lag
        Well how about a March 2009 report suppressed by the US EPA? http://cei.org/cei_files/fm/active/0/DOC062509-004.pdf Or the following from Dr. Nicoals Scafeta. http://yosemite.epa.gov/ee/epa/wkshp.nsf/84E74F1E59E2D3FE852574F100669688/$file/scafetta-epa-2009.pdf There has been climate variation over the past 1000 years - and I have referenced the Hadley Centre Technical Note 5 and other sources. There are 50 year cycles in global surface temperature, Arctic surface temperature, American surface temperature, sea surface temperatures, Australian, American, Indian, Asian and African rainfall, west coast US fisheries and cycles of sardine or anchovy in Monterey Bay. There is decadal variation in cloud cover. An increase in shortwave radiation at the surface of 3.5 W/m2 between 1984 and 1998 and a decrease of 2 W/m2 since. Global surface temperature is currently at the 1979 to 1998 average. ARGO data shows no increase in ocean heat content. Together they are the reservoirs of most of the global heat content - a global heat content that should rise with C02 acording to AGW theory. These are all empirical reality going begging for a theory. By all means, dispute the theory but stay true to the data.
127893. Riccardo at 09:38 AM on 13 July 2009
        Climate time lag
        Despite so many words spent on GCR here, there are still so many unclear things about the theory, so many unexplained climate facts, that while it's certainly worth being studied by scientists it's quite a long way from being complete. In other words, it didn't even begin to put it all together.
127894. Robbo the Yobbo at 06:24 AM on 13 July 2009
        Climate time lag
        I was going to finish that but posted instead. I was looking for the hiding place for that damn heat and someone suggested it wss in melting ice. Yhe estimates of mass sea level increase are not precise - but 1 mm/year from the land/ice contribution seems reasonable - see the discussion in the Willis et al link provided. So the mass rise approximately equals the volume of melted ice as an order of magnitude calculation. There is not nearly enough melting to hide the heat. Most of the heat storage is in the oceans - 95% appromimately. Stop quibbling and put it all together. No one denies that carbon dioxide is a greenhouse gas. But now we have a situation where the planet is not warming because of natural variability - we need to appreciate the modes of natural variation before we can understand human impacts.
127895. Robbo the Yobbo at 06:05 AM on 13 July 2009
        Climate time lag
        I don't know where to start. Except to say that the medieval warm period was real as was the little ice age. All of the temperature renconstructions show this. The Loehle paper is downloadable at the site linked to. The data sources are described in the paper. Steric sea levels have not increased since 2004 - no thermal expansion therefore no increase in ocean heat content. No increase in atmospheric temperature - currently at the 1979 to 1998 average. http://www.drroyspencer.com/latest-global-temperatures/
127896. Mizimi at 05:00 AM on 13 July 2009
        Climate time lag
        "In the late 1980s and early 1990s, rapid and large climate changes had been identified in Full Glacial sediments from the North Atlantic (Figure 9; Heinrich 1988; Bond et al. 1992). The Greenland ice core also showed evidence of similar variability (Dansgaard et al. 1993). These results convinced many people of the importance of abrupt climate changes (Weart 2003); that is,the climate may change as a step function. Efforts were made to relate these results to climate “episodes” that had been known for many years, such as the Younger Dryas Period (e.g. Wright 1989; Broecker et al. 1988). However, much of this work was done in the North Atlantic region,where large outbreaks of icebergs and pack ice could amplify the actual climate changes. Subsequently, climate variability of this timescale was also identified in postglacial sediments from some ocean cores in the North Atlantic, and it was suggested that Holocene climates varied significantly at a periodicity of roughly 1500 years during both interglacial and glacial times, as well as during the transition between them (Figure 9; Bond et al., 1997, 2001). This has important consequences for the identification of possible causes. The spatial distribution of the changes must be known, and this has occupied many people for the last decade. We therefore suggest that the dominant millennial-scale climate frequency in the Holocene is not 1500 years, but rather circa 1,000 ± 100 years. This circa 1,000 ±100-year periodicity actually matches better with the record of 14C variations in the atmosphere and 10Be. Cross-spectral analysis of the North Atlantic IRD marine record and cosmogenic nuclide records (14C and 10Be; proxies for solar variability and ocean ventilation changes) shows power at 300-500 and 900 to 1100-year frequency bands during the past 12,000 years (Bond et al., 2001). Hughen et al. (2000) suggest that climate variations such as the Younger Dryas are synchronous with atmospheric 14C changes, interpreted by the authors as ocean circulation changes. This suggests that these climate transitions are associated with major changes in the carbon cycle (Kutzbach notes Figure 19; Stuiver et al. 1995). Therefore it is possible that a weak periodic solar and/or ocean forcing in frequency bands of 300-500 and 900- 1100 years may be the dominant forcing during the Holocene when ice-sheets are less significant components of the climate system. The dominant ca 1500-year periodic signal during glacial regimes could have an internal origin and could explain why this periodicity does not show up in the 14C nor the GISP2 18O record of the past 12000 years (Stuiver et al.1995; Schulz and Paul 2002). Although a ca 1500-year periodic signal has been observed in some marine and terrestrial records (Bianchi and McCave 1999, Hu et al. 2003), we have argued above that individual records may simply be lacking some particular warming or cooling event." "Millennial-scale climate variations in the Holocene " by K Gajewski explores the apparent periodicity of climate changes ..the 1500year cycle referred to above. Climate Variabilityand Change Past, Present and Future Sorry about the address!! It gives some interesting views on 'step' changes in climate during the holocene period.
        Moderator Response: [Sph] Hotlinked to fix page.
127897. Philippe Chantreau at 03:08 AM on 13 July 2009
        Climate time lag
        You can not attribute everything to a cycle,especially since neither DO events, Heinrich events or Bond events have been shown to be truly cyclic in nature. The periodicity of Bond events is estimated by Bond himself with a very large uncertainty. Your sampling bias complaint is unfounded. The data are there, they simply do not show synchronous hemispheric warming with D-O events. The Bipolar Seesaw shows up during the periods considered: http://www.scenta.co.uk/environment/news/cit/1271676/bipolar-seesaw-connects-the-poles.htm Excerpt: "the Antarctic starts to cool every time more warm water starts to flow into the North Atlantic during warm events in the north." NOAA has a nice discussion: http://www.ncdc.noaa.gov/paleo/abrupt/data3.html This article is interesting too: http://www3.interscience.wiley.com/journal/82002936/abstract?CRETRY=1&SRETRY=0 Robbo's link to the Wikipedia article on Bond's events: "the only Holocene Bond event that has a clear temperature signal in the Greenland ice cores is the 8.2 kyr event." The main difference between Bond and DO events is that Bond events are of much smaller nagnitude. Although the oceanic circulation pattern suspected in DO events appears to be conserved, it does not seem to be significant climatically in most cases. The Loehle E&E thing that you link makes no mention of Bond events. Except for not being dendro, what are the data used by Loehle? Your link does not say what the proxies are, where they were gathered, by whom, there is no data publication referenced, just Loehle's own compiled file in excel, which does not really help.
127898. Thumb at 01:15 AM on 13 July 2009
        Climate time lag
        #27: "Let’s neglect the unlikely 6 month rise... We should have had either atmospheric or ocean temperature or both increase – but we have had neither. This effectively falsifies AGW theory." Well I'm convinced. Science is easy.
127899. thingadonta at 22:20 PM on 12 July 2009
        Climate time lag
        re 29: Yeah, a 500 year long, one hemisphere phenomenon. Haven't the IPCC ever heard of sampling density bias? If they are fewer studies in the southern hemisphere, this donest mean it didnt occur there. This is a typical socialist type misinterpretation-ie sampling density/occurrence correlates with fact/importance. I have seen this sort of bias in socio-economic analyses conducted by the public service, which attributes vocation significance/indices to actual number employed in an industry, rather than wages and other factors etc. So doctors, at less than 1% by number in a region, can be done away with....not to mention commuters, investors, etc etc-but I digress.... The chinese have kept good records, and have a strong medieval warm period, as do the Japanese. NZ was settled during this time around AD1000, just like Greenland (which may or may not be correlated, its just interesting), and glacial advances/retreats have actually been dated in NZ and are in line with european glacier advances/retreats. Mayans and Aztecs empires were disrupted by severe droughts. Easter island agriculture declined as T got colder from the time of settlement around ?AD800 (although other factors were also probably at work there). Anyway, the medieval warm period in the southern hemipshere has been detailed by much better methods than the above speculations, and keeps showing up in the data: it isnt a greenland phenomenon. I wonder if anyone has done a study of migrating agriculute in NZ's south and north islands since polynesian settlement around ?AD1000, this could show a trend if the south island for example got colder and farmign was abandoned, progressively moving north after the medieval warm period? I did read somewhere that the polynesians were attempting to grow tropical-type crops in places, but it got too cold for them, maybe they were moving progressively north as the islands went into the little ice age?? But I will have to find the reference. Also of interest, in the book "the Chilling Stars" by Danish solar scientists, a recently melted snow/ice pass in the European Alps in 2003 revealed various items left from both the roman and medieval warm periods-including shoes, clothes and the like-showing the pass was open and travelled in both previous warmings. These items were only exposed in 2003. A roman ruin is also located there, the locals finally found out what this old ruin was for, all the way up in those mountains-it was an ancient roman mountain pass lodging-only very recently reusable for travellers. So much for a greenland-only medieval warm period...
127900. Robbo the Yobbo at 18:50 PM on 12 July 2009
        Climate time lag
        re28 G'day Thingadonta The 1500 year Dansgaard-Oeschger Events become Bond Events in the holocene. There are 10 references listed on Wikapedia and a reasonable summary. http://en.wikipedia.org/wiki/Bond_event There is a 2008 non tree ring reconstruction here: http://www.ncasi.org/publications/Detail.aspx?id=3025 which discusses the geographical problem and which, incidentally, shows the warm period as warmer than 1998. Is the IPCC still arguing that this was a Northern Hemisphere phenomenon and therefore it doesn’t matter. What would they imagine the ‘physical mechanism’ is behind that? And as for only Greenland warming. lol Cheers Robbo

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