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Comments 129301 to 129350:

129301. 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)
129302. 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.
129303. 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…..
129304. 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."
129305. 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.
129306. 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.
129307. 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.
129308. thingadonta at 16:39 PM on 13 July 2009
        Climate time lag
        the last post should be "re:41" sorry
129309. 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).
129310. 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.
129311. 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'...
129312. 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
129313. 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.
129314. 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.
129315. 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.
129316. 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.
129317. 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/
129318. 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.
129319. 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.
129320. 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.
129321. 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...
129322. 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
129323. Robbo the Yobbo at 18:07 PM on 12 July 2009
        The CO2/Temperature correlation over the 20th Century
        Seriously - did no one that the post confused sea surface temperatures and than near surface atmospheric temperature. There is a link by energy transfer but the series are measured in different ways. The temperature is measured in water - air temperature is measured in air. The fact that they both show cooling trends? Oceans surfaces cooled after the mid 1940's as did near surface atmosphere temperature. The warming and cooling was especially pronounced in the Arctic. Arctic air temperature change amplification and the Atlantic Multidecadal Oscillation Chylek Petr, Chris K. Folland, Glen Lesins, Manvendra K. Dubeys, and Muyin Wang: 2009: 'Arctic air temperature change amplification and the Atlantic Multidecadal Oscillation'. Geophysical Research Letters (in press). “Understanding Arctic temperature variability is essential for assessing possible future melting of the Greenland ice sheet, Arctic sea ice and Arctic permafrost. Temperature trend reversals in 1940 and 1970 separate two Arctic warming periods (1910-1940 and 1970-2008) by a significant 1940-1970 cooling period. Analyzing temperature records of the Arctic meteorological stations we find that (a) the Arctic amplification (ratio of the Arctic to global temperature trends) is not a constant but varies in time on a multi-decadal time scale, (b) the Arctic warming from 1910-1940 proceeded at a significantly faster rate than the current 1970-2008 warming, and (c) the Arctic temperature changes are highly correlated with the Atlantic Multi-decadal Oscillation (AMO) suggesting the Atlantic Ocean thermohaline circulation is linked to the Arctic temperature variability on a multi decadal time scale.” “In the following analysis we confirm that the Arctic has indeed warmed during the 1970-2008 period by a factor of two to three faster than the global mean in agreement with model predictions but the reasons may not be entirely anthropogenic. We find that the ratio of the Arctic to global temperature change was much larger during the years 1910-1970.” “We consequently propose that the AMO is a major factor affecting inter-decadal variations of Arctic temperature and explaining [the] high value of the Arctic to global temperature trend ratio during the cooling period of 1940-1970.” Again, ocean and atmospheric temperatures are heading down in this 25 year cycle. Which bit of multi-decadal oscillation is so hard to grasp?
129324. Robbo the Yobbo at 18:06 PM on 12 July 2009
        The CO2/Temperature correlation over the 20th Century
        I suppose it is simple to not see the wods for the trees. The post did confuse sea surface temperatures and with near surface atmospheric temperature. There is a link by energy transfer but the series are measured in different ways. Water temperature is measured in water - air temperature is measured in air. They are a different data series and provide independant support for the mid century cooling.
129325. Robbo the Yobbo at 17:59 PM on 12 July 2009
        The CO2/Temperature correlation over the 20th Century
        Seriously - did no one that the post confused sea surface temperatures and than near surface atmospheric temperature. There is a link by energy transfer but the series are measured in different ways. The temperature is measured in water - air temperature is measured in air. The fact that they both show cooling trends? Oceans surfaces cooled after the mid 1940's as did near surface atmosphere temperature. The warming and cooling was especially pronounced in the Arctic. Arctic air temperature change amplification and the Atlantic Multidecadal Oscillation Chylek Petr, Chris K. Folland, Glen Lesins, Manvendra K. Dubeys, and Muyin Wang: 2009: 'Arctic air temperature change amplification and the Atlantic Multidecadal Oscillation'. Geophysical Research Letters (in press). “Understanding Arctic temperature variability is essential for assessing possible future melting of the Greenland ice sheet, Arctic sea ice and Arctic permafrost. Temperature trend reversals in 1940 and 1970 separate two Arctic warming periods (1910-1940 and 1970-2008) by a significant 1940-1970 cooling period. Analyzing temperature records of the Arctic meteorological stations we find that (a) the Arctic amplification (ratio of the Arctic to global temperature trends) is not a constant but varies in time on a multi-decadal time scale, (b) the Arctic warming from 1910-1940 proceeded at a significantly faster rate than the current 1970-2008 warming, and (c) the Arctic temperature changes are highly correlated with the Atlantic Multi-decadal Oscillation (AMO) suggesting the Atlantic Ocean thermohaline circulation is linked to the Arctic temperature variability on a multi decadal time scale.” “In the following analysis we confirm that the Arctic has indeed warmed during the 1970-2008 period by a factor of two to three faster than the global mean in agreement with model predictions but the reasons may not be entirely anthropogenic. We find that the ratio of the Arctic to global temperature change was much larger during the years 1910-1970.” “We consequently propose that the AMO is a major factor affecting inter-decadal variations of Arctic temperature and explaining [the] high value of the Arctic to global temperature trend ratio during the cooling period of 1940-1970.” Again, ocean and atmospheric temperatures are heading down in this 25 year cycle. Which bit of multi-decadal oscillation is so hard to grasp?
129326. David Horton at 17:49 PM on 12 July 2009
        The CO2/Temperature correlation over the 20th Century
        When reading the amazing theses from Thingadonta, Robbo, and Quietman, I am constantly reminded of something you learn very early on when training to be a scientist - a certain aphorism by Mr Ockham.
129327. thingadonta at 17:22 PM on 12 July 2009
        Climate time lag
        re24" "the Avery-Singer piece refers to Dansgaard-Oeschger events. There is an abundant litterature on the subject. These events appear to be mainly Northern hemisphere occurrences and only in Grenland did they produce large warmings" No. There is abundant literature, ignored by the IPCC, that nz, china, siberia,central america and other places warmed in line with Europe in the medieval warm period. To say it was confined to europe/greenland is not correct; IPCC selects eg another example of tree rings in TASSIE AND then compares them to urban heat islands in recent tassie, more of the same hockey stick rubbish, completely ignoring data from NZ and other places. IPCC should be called the international panel of cherry pickers. IPCP. Its detailed in the singer and avery book, and peer reviewd articles are listed. It was no confined to northern hemisphere and greenland etc. The 1500 year cycle is not even with time across its warming/cooling trends.
129328. Robbo the Yobbo at 15:54 PM on 12 July 2009
        Climate time lag
        Is heat hiding in the molecule? ‘First, from 2004 to the present, steric contributions to sea level rise appear to have been negligible…Although the historical record suggests that multiyear periods of little warming (or even cooling) are not unusual, the present analysis confirms this result with unprecedented accuracy.’ ‘The rate of ocean mass increase based on GRACE during the study period is similar to previous estimates based on observed melting of land bound ice, which tend to be around 1 mm/yr [Shepherd and Wingham, 2007; Kaser et al., 2006; Rignot and Kanagaratnam, 2006; Velicogna, 2006; Chen et al., 2006]. However, most of the 3.5 mm increase seems to have occurred in a 6-month period between late 2004 and early 2005. On the other hand, the inferred estimate (Jason – Argo) implies a much greater rate of ocean mass increase and significant uncertainties in the trend over the GRACE record remain. Until these issues are resolved, the long-term rate of ocean mass increase remains uncertain.’ http://ecco.jpl.nasa.gov/~jwillis/willis_sl_budget_final.pdf Let’s neglect the unlikely 6 month rise and assume a mass sea level rise of 5mm over 2004 to 2008. Using the area of the ocean and the enthalpy of fusion for water (use Wikipedia) gives a total enthalpy of 5.6 x 10 to the power of 20 J – about 1/250th of the total ocean heat content. This of course is heat converted to internal kinetic energy – i.e. hiding in the molecule. Even if we increase the non steric sea level rise by an order of magnitude - there is still a substantial energy deficit. This is heat that has to come from somewhere. The additional heat from IPCC net forcing is about 4 x 10 to the power of 22 J over the last 5 years – check my calcs (please check my calcs). We should have had either atmospheric or ocean temperature or both increase – but we have had neither. This effectively falsifies AGW theory.
129329. Robbo the Yobbo at 12:06 PM on 12 July 2009
        Climate time lag
        There is an 11,000 year sunspot reconstruction on Wikapedia. It is of course based on the so called cosmogenic isotopes is ice cores. These are isotopes of carbon and beryllium that are formed when affected by ionising cosmic radiation. The amount of cosmic radiation hitting atmosphere is modulated by the heliosphere which is in turn associated with sunspot count. http://en.wikipedia.org/wiki/Solar_cycle I wouldn't get too caught up with looking for precise cycles - just note that it goes up and down. The heliosphere changes as a result of internal cycles in the Sun such as the 11 year cycle, the 22 year solar polar magnetic reversal cycle and with the orbits of particularly the large outer planets. The time periods associated with these cycles are averages – the heliosphere doesn’t change on cue or even smoothly. A reconstruction of heliospheric magnetic intensity – based on carbon 14 in ice cores – is found here. http://en.wikipedia.org/wiki/File:Carbon14_with_activity_labels.svg Note the ‘Modern Maximum’ which went off the chart last century. Might it be related to the syzygy of March 10 1982? At any rate, the magnetic intensity of the heliosphere is declining rapidly – a decline that will continue sporadically over the next few centuries. It is typical that the error bounds from this kind of research are greater the further back in time you go. The last thousand odd years have been correlated with temperature reconstructions. The 1000 year temperature reconstructions from tree rings and oxygen 18 are of course bounded by large potential errors. But both the temperature reconstructions and the very fallible and partial historic records suggest a high point in global temperature around 1000 AD – called the ‘Medieval Optimum’ – and a low point in the 1700’s called the ‘Little Ice Age’. The correlation is between cosmic radiation and global temperature. Conceivably there could be a link between the heliosphere and solar irradiance. However, it seems that solar irradiance does not vary significantly. This has led some to posit a more subtle connection of the heliosphere to climate through ionisation of aerosols and subsequent formation of cloud condensation nuclei. CERN is currently undertaking a program of experimental investigation of this physical process. A review of the correlations, the hypothesis and the experimental design is provided at: http://arxiv.org/abs/0804.1938 The movie version is available here: http://cdsweb.cern.ch/record/1181073/ Sunspots have been counted since soon after the invention of the telescope by Hans Lippershey in Holland in 1608. The low point is at 1650 to 1700 AD which is associated with very low temperatures in Europe and with low temperatures in the millennial temperature reconstruction. http://www.cru.uea.ac.uk/cru/info/milltemp/ Global temperature rose 1000 years ago, dipped to the 1700’s and has risen since very much in line with the cosmogenic isotope count. Note also the shorter term variation in temeperature. The instrumental record of global surface temperature again shows shorter cycles – noting again that the reliability of the data diminishes with time. Increasing to 1880, declining to 1910, increasing to 1945, declining to 1975, increasing to 1998 and declining to June 2008. There are other 20 to 30 year cycles. The Pacific Decadal Oscillation – a cool mode form the mid 1940’s to the mid 1970’s and a warm mode from 1976 to 1998. The PDO was initially defined in terms of a relationship between sea surface temperature in the north eastern Pacific and fisheries productivity. In a cool mode, cold and nutrient rich water upwells strongly boosting productivity. In a warm mode, the upwelling is suppressed. Biology suggests that the current cool mode commenced in after 1999. http://jisao.washington.edu/pdo/ ENSO also has 20 to 30 cycles. These can be seen clearly in the multi-variate ENSO index of Claus Wolter. http://jisao.washington.edu/pdo/ There was a notable shift in climate in 1976/77 known as the ‘Great Pacific Climate Shift’. It is no accident that the periods of warming and cooling of the Pacific sea surface and global near surface atmospheric temperature are the same. Is there a link between these phenomenon and neutron counts on a solar cycle? I don’t know and I don’t care. Clouds, oceans and atmosphere are physical systems with a lot of momentum when they get going. They are not switched on and off like a light globe. What does the cloud evidence say? From the beginning of reconstructions in 1984, Earth albedo decreased by 1% (3.4 Wm2) to 1998. In 1999/2000 Earth albedo increased by 0.6% (2 Wm2) and has essentially stayed there. http://www.bbso.njit.edu/Research/EarthShine/ It suggests a physical explanation for surface and ocean warming and cooling. Actual changes in shortwave forcing as a result of changes in cloud cover. I am more interested in how it might work as a cause of the PDO and decadal ENSO modulation. There is a layer of warm surface water overlaying colder subsurface water. Subsurface currents are driven by cold water sinking at high latitudes and by the rotation of the planet. Upwelling of cold and nutrient rich water occurs as a result of physical characteristics in a few spots – especially the north eastern Pacific and in the Humboldt Current off South America. A little surface cooling and cold water upwells strongly in the north eastern Pacific. A little surface warming and the upwelling is suppressed. The central Pacific undergoes the same heating and warming over which is superimposed the 2 to 7 year ENSO cycle. This is a theory that probably requires 20 more years of cloud data. Regardless of the cause, the PDO, the decadal modulation of ENSO and suppressed global near surface atmospheric temperatures are with us to about 2024. El Niño are weaker in cool PDO periods. The next El Niño will not be a 1998 event – and global surface temperatures will continue to fall. In the longer term, the evidence for a cosmic ray/ climate link is strong. This suggests a cooling influence over the next couple of centuries – regardless of the mechanism.
129330. David Horton at 11:54 AM on 12 July 2009
        The CO2/Temperature correlation over the 20th Century
        "The Arctic is not about CO2. It's about tectonic plates." - what an astonishing coincidence then, that the unprecedented melt is happening just as temperatures rise with increasing CO2.
129331. Philippe Chantreau at 05:39 AM on 12 July 2009
        Climate time lag
        Thingadonta, if the cycle is 1500 yrs and it last started in 1750, how can we be halfway through? Seems half way would be in 2500.
129332. Philippe Chantreau at 05:33 AM on 12 July 2009
        Climate time lag
        Not really.Wouldn't explain how mountain glaciers are melting everywhere. From what I remember, the Avery-Singer piece refers to Dansgaard-Oeschger events. There is an abundant litterature on the subject. These events appear to be mainly Northern hemisphere occurrences and only in Grenland did they produce large warmings. Most analyses use Greenland ice cores. They are found throughout the latest glaciation until about 23000 yrs ago, where they no longer appear in the paleo record. Furthermore, some research also shows that, while the Northern Hemisphere warmed in DO events, the Southern hemisphere cooled. THe best explanations advanced so far postulates changes in ocean currents leading to changed heat distribution.
129333. Quietman at 04:56 AM on 12 July 2009
        Arctic sea ice melt - natural or man-made?
        Patrick " 523. Should I be so optimistic as to expect a room of adults to agree that the sun is a star?" Maybe Not, LOL. Some think the Earth was created 6,000 years or so, and rely on prophets of Doom and Death. The wackos expect the Earth to end in 2012 and Hansen says were are "Toast". With wackos like this what can we expect.
129334. Quietman at 04:48 AM on 12 July 2009
        Climate time lag
        Philippe Possible the AMO. I'm not sure. I have not read Cazenave's paper but it sounds about right.
129335. Quietman at 04:44 AM on 12 July 2009
        Climate time lag
        Re: Lee Grable at 04:44 AM on 9 July 2009 Maybe you should take some lessons from the Real Climate website. They don't suffer fools over there. Cuts way down on the bitchiness. Real Climate is the worst possible propaganda site on the entire web. That's Hansen and buddies. Can't expect a skeptic view not to be derision there. Just asking a simple question results with a sarcastic answer, never a true answer. You can't trust any alarmist. It's like a scientific reason for a 6,000 year old Earth.
129336. Quietman at 04:30 AM on 12 July 2009
        It's the sun
        Gord Re: "Don't understand?...It's OK....everybody else will." Sorry. I don't understand. I don't what is "Baghdad Ali".
129337. Quietman at 04:17 AM on 12 July 2009
        The CO2/Temperature correlation over the 20th Century
        "We did not about the increase" s/b We did not KNOW about the increase
129338. Quietman at 04:15 AM on 12 July 2009
        The CO2/Temperature correlation over the 20th Century
        Thumb The Arctic is not about CO2. It's about tectonic plates. We did not about the increase in the Arctic ridge until the past couple of years, It was even not about the under volcanoes erupted until they put together the quakes with the eruptions BEFORE the recent eruptions in Alaska. They also show the subduction zone in NE Greenland but they recognize the thin crust and hot spot and Greenland active volcanoes the "might add to the glacier melt". See the volcano threat here. http://www.skepticalscience.com/volcanoes-and-global-warming.htm
129339. Dan Pangburn at 23:25 PM on 11 July 2009
        It hasn't warmed since 1998
        Since the year 2000, atmospheric carbon dioxide has increased 18.4% of the increase from 1800 to 2000. According to the average of the five reporting agencies, the trend of average global temperatures since 1998 shows no increase and from 2002 through 2008 the trend shows a DECREASE of 1.8°C/century. This SEPARATION (there have been many others) corroborates the lack of connection between atmospheric carbon dioxide increase and average global temperature. I wonder how wide the separation will need to get before the IPCC and a lot of others are forced to realize that maybe they missed something. As the atmospheric carbon dioxide level continues to increase and the average global temperature doesn’t it is becoming more and more apparent that many Climate Scientists have made an egregious mistake and a whole lot of people have been misled.
129340. Mizimi at 21:56 PM on 11 July 2009
        Climate's changed before
        Thanks QM; an interesting article. I shall have to go and revisit clathrate physical/chemical properties. From what I recall, they only form under extreme pressure/low temperature conditions ( which is why they are mostly found in very deep water).
129341. Mizimi at 21:34 PM on 11 July 2009
        Water vapor is the most powerful greenhouse gas
        There is considerable evidence that man's activities are changing the distribution of WV with consequential effect on climate. Deforestation has decreased evaporation by around 3000cubic/k/a which is mostly balanced by increases from agricultural evaporation of # 2600c/k/a. To that must be added the estimated loss of 400 c/k/a from industry, commercial, municipal use and reservoirs. The system seems to be in balance. However, the flow pattern of WV has changed, with subsequent effects on climate....this is explored from an agricultural view in "Human modification of global water vapor flows from the land surface." published online at PNAS ( the address is just too long to post) and the authors conclude that until modellers include redistribution of WV, GCM's cannot be considered to adequately describe real world conditions.
129342. thingadonta at 20:13 PM on 11 July 2009
        Greenland was green in the past
        Greenland was relatively warm between about 800-1300 AD due to the well-defined 1500 year solar cycle, as detailed by Singer and Avery in: "Unstoppable global warming every 1500 years". We are currently in another upswing in the solar cycle, which started about 1750, and which will probably rise about another 0.5-1 degree C over the next few hundred years. Current T to the 21st century is entirely in line with this solar cyle trend. C02 is irrelevant to this cycle,it has been traced 600 times over the last 1 million years in ice cores, and is a result of an overlap between the 87 and 210 year solar cycles. It is well documented, world wide, and climatologists have conveniently forgotten about it (see reference given above). Greenland was settled by vikings during the last solar warming period, which is also why they travelled so far in general during this time period-the northern world was warm.
129343. thingadonta at 19:01 PM on 11 July 2009
        Climate time lag
        There is a 1500 (1470) year natural solar cycle, which is a superimposed 87 year and 210 year solar cycle overlap. It has been traced 600 times over the last 1 million years in ice cores, is very consistent, and we are currently about halfway through the latest solar warming trend, which started in about 1750; T will rise another 0.5-1 degree C over the next few hundred years, from the sun, as it has already risen about 0.8-1 degree C since 1750, also because of the sun. C02 is irrelevant to this trend. Current T is entirely in line with this well-defined 1500 year solar trend. Reference: "Unstoppable global warming every 1500 years" by F.Singer and D.Avery. They also trace numerous studies which confirm the trend, eg the medieval warm period, the little ice age etc etc.
129344. Philippe Chantreau at 15:59 PM on 11 July 2009
        Climate time lag
        The Cazenave paper states that the sea level increase of the past 5 years is due to increase of the oceans' mass due to shrinking land ice, both from polar ice caps and mountain glaciers. It seems that perhaps that could prevent too much warming from comparatively modest forcings. There has to be a reason for all that ice to melt. It also seems to undermine your assertion about the "total energy in the system." We're missing big chunks of ice that have now become water. What is exactly the 1000 to 1500 years cycle that you refer to?
129345. Robbo the Yobbo at 10:51 AM on 11 July 2009
        Climate time lag
        I wonder why the cloud nucleation should be instantaneuos and why there should be therefore an immediate link to the 11 year solar cycle. Ionised aerosols are much smaller than cloud condensation nuclei. It must take some time to coalesce into larger particles and then to accumulate water vapour. There is an obvious 20 to 30 year cooling and warming pattern in global temperatures - as well as longer (1000 to 1500 year) cooling and warming. Unless we can distinguish clearly between natural variation and anthropogenic global warming - the attribution problem is not solved. The heliospheric/cosmic ray/ cloud connection is the leading contender for a source of the variation on these timescales. The basis of the concept relies is in analysis of beryllium and carbon isotopes form ice cores. The correlation over more than a thousand years is best with a 10 year lag. But this is only a correlation. The essential question is, because it is fundamental to assumptions about TOA fluxes (and therefore the time lag and cimate sensitivity), is whether clouds are changing in reality and from observation - and what are the implications. Clouds decreased from 1984 (when the reconstructions commence) to 1998 - with an increased shortwave forcing at the surface of 3 to 4 W/ms. Cloud cover has subsequently increased decreasing the shortwave forcing by 2 W/m2. Ocean heat content has, at a minimum, not increased since 2008. That is clear in: Sea level budget over 2003–2008: A reevaluation from GRACE space gravimetry,satellite altimetry and Argo A. Cazenave a,⁎, K. Dominh a, S. Guinehut b, E. Berthier a, W. Llovel a, G. Ramillien a, M. Ablain b, G. Larnicol b Also in the recent work by Willis referred to elsewhere and the 2009 Energy and Environment Article by Loethe. At the same time the monthly values of global surface temperature continue to decline. People are hoping that surface temperature will reach a new record if an El Nino forms in the boreal summer. The strength of El Nino is statistically correlated with the state of the Pacific Decadal Oscillation. While the PDO is cool - it is hugely unlikely that a strong El Nino will form. NASA is predicting record temperatures when El Nino returns. It is not even close this year and we will return to La Nina next year. Energy can be transferred betwen the ocean and atmosphere - especially in ENSO events. However the total energy of the ocean and atmosphere (barring volcanos) cannot decline with the forcings given by the IPCC. It seems likely that there is less energy in the climate system today than in 2005. This is a serious problem for AGW theory. - although I am anticipating that Chris will argue that there is more energy. It is hiding perhaps under a rock.
129346. shawnhet at 06:56 AM on 11 July 2009
        Climate time lag
        Philippe, you may not care for the tone of the Shaviv's reply, but it seems to me that the long-term correlation btw CRF and climate has very strong evidentiary support, whether or not it can be separated from noise for the short term. There are many papers that demonstrate such a correlation - see here for example. http://geology.gsapubs.org/content/37/1/71.abstract BTW, I would not be so quick to accept chris's assertion that there is no link btw CRF and clouds. In the discussion on Shaviv's page, he states the following: "The next criticism Sloan and Wolfendale raise is the fact that when the cloud cover is correlated with the cosmic ray flux over the 11-year solar cycle, it appears that the cloud cover leads the cosmic ray flux variations by about 3 months (see panel 2 of fig. 1 above). If cosmic ray flux affect the cloud cover, such a lead should not be observed." (Shaviv then goes on to discuss his reasoning why this objection doesn't apply). Cheers, :)
129347. Robbo the Yobbo at 06:17 AM on 11 July 2009
        Does ocean cooling disprove global warming?
        Look - you can have a go at me but leave Freddy out of this. Svensmark-Friis-Christensen have obviously interpreted the data they present differently to you. But this was a paper that you originally introduced. Let's not worry about that - but concentrate on the peer reviewed work. To quote Jasper Kirkby – ‘The data for the period 1957–2001 show the solar cycle modulation and the effect of geomagnetic shielding, which leads to reduce fluxes and modulation amplitudes at lower geomagnetic latitudes (Fig. 7). Although the GCR reduction occurred mainly in the first half of the twentieth century (Fig. 6), the cosmic ray measurements shown in Fig. 7 suggest a continuing decreasing trend in the second half of the century, by a few per cent in the lower stratosphere and upper troposphere… On the other hand, there has been a substantial increase of solar magnetic activity since the Little Ice Age, and a corresponding reduction of the cosmic ray intensity. This suggests that the possibility of an indirect solar mechanism due to cosmic-ray forcing of the climate should be seriously considered.’ There is a cloud and cosmic ray correlation here – not sure how reliable it is. http://www.sciencebits.com/CosmicRaysClimate I don’t think it works like that – there is a lag between cosmic ray intensity and global cloud cover. The basis of the idea is in the record of cosmogenic isotopes preserved in ice cores. A well known correlation of isotopes of beryllium and carbon and global temperature reconstruction over more than a thousand years. Hence the link between heliospheric modulated cosmic rays and climate. The best correlation is with a 10 year lag. The most likely connection is through ionisation of aerosols and subsequent growth of cloud condensation nuclei. The core of the science is pretty solid and widely accepted as the dominant cause of climate change prior to 1975. We are only quibbling about a supposed divergence of trends post 1975. Neutron counts peaked in 1991. Usoskin calculated a cosmic ray modulation parameter which peaked strongly in 1991. Cloud cover peaked in 1998. Global surface temperature peaked in 1998. Ocean temperatures are falling or at least steady in the ARGO data. Usoskin et al - Heliospheric modulation of cosmic rays: Monthly reconstruction for 1951–2004 http://cosmicrays.oulu.fi/phi/2005JA011250.pdf I have referenced CERN, the Hadley Centre, the Max Planck Institute and the Sodankyla Geophysical Observatory. There is nothing dubious about the science. The only question is by how much cosmic rays influenced climate in the late 20th century.
129348. Philippe Chantreau at 04:45 AM on 11 July 2009
        Climate time lag
        A question for Chris, since I could not read through that paper: does "an increase in ionization by a factor of 10" correspond to what happens in nature?
129349. Philippe Chantreau at 04:42 AM on 11 July 2009
        Climate time lag
        The CRF-cloud relation is not at all so obvious as "skeptics" like to claim. Chris' point about the lack of cyclic variations in phase with solar cycle is a major hurdle in pursuing that hypothesis. Sawhnet, would you expect anything not in defense of his pet theory on Shaviv's personal blog? Any blog post including these words "many in the climate community try to do their best to disregard the evidence" is going to be met with great skepticism by me. I'm sure that, as a self proclaimed skeptic, you can understand.
129350. shawnhet at 01:58 AM on 11 July 2009
        Climate time lag
        Chris, can you post the material pertaining to the "20-1500 times realistic true atmospheric levels" you mention above? The only link to the paper I have found is behind a pay wall. I find this interpretation odd, because it seems to contradict earlier work by the some of the same authors see here - http://adsabs.harvard.edu/abs/2006cosp...36.2889P where they claim that the levels of SO2 ozone and WV are atmospherically relevant. Further, just for people's information, here is a very good discussion on the state of play of the cosmic ray hypothesis IMO. http://www.sciencebits.com/SloanAndWolfendale "One last point. Although many in the climate community try to do their best to disregard the evidence, there is a large solar-climate link, whether on the 11-year solar cycle (e.g., global temperature variations of 0.1°C), or on longer time scales. Currently, the cosmic-ray climate link is the only known mechanism which can explain the large size of the link, not to mention that independent CRF variations were shown to have climatic effects as well. As James Whitcomb Riley supposedly once said: "If it walks like a duck and quacks like a duck, I would call it a duck"." Cheers, :)

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