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  • Contrarians and consensus: The case of the midwife toad « RealClimate
    very little that anybody can do about it no matter which tact they take However since climate change is so slow either position is totally viable politically because neither position can really do anything to control CO2 levels Unfortunately some people have resorted to exaggeration in an attempt to advance their position This is true for both sides of the debate So although the science is technically settled for the most part the political turmoil will continue for a very long time 8 Gwyan Rhabyt says 7 Dec 2008 at 2 04 PM The parallel goes even further When Kammerer says Take a very pertinent case The next generation of Americans will be born without any desire for liquor if the prohibition law is continued and strictly enforced he uses the same impossible to falsify language of the climate contrarians That prediction doesn t count Lamarckians would say because prohibition wasn t strictly enough enforced We hear similar language today 9 Jordiet says 7 Dec 2008 at 2 07 PM Mendelevian genetics You probably mean Mendelian genetics or do I miss something Response whoops fixed gavin 10 Edward Greisch says 7 Dec 2008 at 2 13 PM A good book on methods for changing minds and behavior Reference Influencer by Patterson Grenny Maxfield McMillan and Switzler Step 1 Set an example that is observable The Mad scientist idea is untenable once they see that you are a nice person Step 2 Tell stories People react negatively to being told that they are wrong Tell a long but not tall story instead Soap operas on radio have helped slow the spread of AIDS Step 3 Demonstrations work better than instructions Vicarious experiences cause brain neurons to light up as if the viewer were performing the same action Instructions are not understood Simple experiments are good They may not know what the words you use mean Step 4 Make sure they have a way out of whatever their problem is If you don t solve their problem they just give up and continue their old ways They DO have some sort of problem What is it Observe the opposition carefully to determine what their problem is That book says Change 1 or 2 vital behaviors They may seem like very minor things but the result can be major I am on page 84 so I have just started reading this book Not from the book The best deal would be to get science into the public schools Make science a laboratory course in elementary school Require 4 years of physics 4 years of chemistry 4 years of biology and 8 years of math of all students in high school 11 cogito says 7 Dec 2008 at 2 20 PM And today there are examples of climate contrarians who are creationists or anti vaccine campaigners Is this sentence worthy of a true scientist And what is the message Response It s an observation nothing more gavin 12 Patrick 027 says 7 Dec 2008 at 2 37 PM The point is that without Lamarckianism none of the striving and achievement of a parent impacts their progeny s genetic material That was a depressing thought for many people what is the point of striving at all So strange did they never expect to inherit money infrastructure scientific and technological advancements link to climate do they never expect green tech etc 13 Prof Bleen says 7 Dec 2008 at 2 39 PM These are very good points In the first paragraph however it should read Mendelian genetics and not Mendelevian genetics 14 Leonard Ornstein says 7 Dec 2008 at 3 00 PM Gavin Your recount of the infamous Kammerer story and its possible relevance to the motivation of many deniers may be on the mark But you must also allow that some skeptics that you lump with deniers may occasionally have valid points to make And maybe they deserve more attention here than analysis of the philosophical beliefs of deniers I m definitely not a denier However from my naive frame of reference a biologist who is more expert on Kammerer and Watson Crick than on realclimate I would much prefer seeing what you have to say about Pat Keating s latest article Simple radiative models for surface warming and upper troposphere cooling in the Int J Climatol 2008 just published online I find it quite compelling as an explanation for the probable significance of the differences between the radiosonde data and GCM s predictions of tropical environmental lapse rates as effectively poo pooed in your recent Santer et al article My acute interest is mostly on the possibility that GISS Model E may regularly underestimate tropical precipitation just because it neglects the radiative subtleties that Keating addresses Response Actually most models overestimate tropical precipitation by around 10 compared to the satellite climatologies which may be underestimates in any case I don t know where the overestimate idea comes from I haven t read Keating 2008 but I will at some point and possibly address it then gavin 15 John Philip says 7 Dec 2008 at 3 14 PM Instead ideas get accepted because of the increasing weight of evidence that supports them and that usually comes in dribs and drabs A replication here a theoretical insight there a validated prediction etc Only in hindsight does there appear to be a clean sequence of breakthroughs that can be seen to have led inexorably to the new conclusions A common meme amongst the contrarians is that the IPCC et al came to the conclusion of GHG forced warming faute de mieux or by elimination it cannot be anything else therefore it must be CO2 Leaving aside the question of the literature on detection and attribution what I would find useful when fighting the good fight would be some examples of succesfully validated predictions from the theory preferably that are unambiguously due to GHGs and with supporting peer reviewed evidence It is an article of faith among the target audience that models are tweaked or trained to reproduce past trends I know I know let s not repoen that one so any model free examples would be useful additions to the toolkit I can think of Hansen s Scenario B the IPCC model projections published in the TAR which showed a projected midrange surface temperature gain of c0 35c from 1990 2010 a good agreement with the observed trend so far sorry Lucia ditto the accelerating sea level rise Arctic ice loss stratospheric cooling does this effectively rule out solar forcing SSTs and ocean heat content the observed increase in atmospheric water vapour as reported recently in GRL Any other low hanging fruit Hurricane intensity seems controversial what about the DTR cheers JP 16 Manny in Canada says 7 Dec 2008 at 3 24 PM today there are examples of climate contrarians who are creationists or anti vaccine campaigners Though possibly this is just coincidence or is it There are examples indeed But the majority of contrarians are in fact scientists including climate scientists And there are examples of climate alarmists who are lawyers politicians and other professional spin doctors It is not a coincidence Thankfully as for Darwinism vs Lamarckism we are talking about a scientific issue Given enough time the sum of good objective data will convince most everyone 17 Phillip Huggan says 7 Dec 2008 at 3 49 PM Not relavent to the post I wonder if the next generation of space observatories http planetquest jpl nasa gov TPF tpf earths cfm could be useful in establishing the bounds of Milankovitch orbital cycles We should find many rocky planets orbiting Sol sized suns at various orbital eccentricacies Id think some of these brainstormed telescopes should be able to tell if a planet has liquid water ice or some combo Maybe the phase states for other substances too So if a planet is found that has a certain orbital eccentricacy yet has more or less water than expected it may be because there are holes in existing Milankovitch theory that could be plugged by exoplanet observations There are many other factors including geology that won t be observable If the observatories are powerful enough to tell atmospheric compositions it could rule out many factors Just an idea that maybe hasn t been considered and maybe should be considered in the suite of instruments that will be used by these fantastic spacecraft 18 wmanny says 7 Dec 2008 at 4 14 PM I m not sure how changing the subject advances any understanding of the climate science from climate scientists that realclimate purports to promote The proprietors of this site have been admirable in their impatience for the non sequitur and I look forward to their returning to the topic This straw man s legs are wobbling before he can even stand 19 John Lang says 7 Dec 2008 at 4 25 PM Hansen et al 1988 had a baseline starting point of 1960 at O You could perhaps use 1985 as the starting point as well since the temp was very close to the same 0 that year 0 1C and that was the last official annual temperature data available at the time of the model predictions Scenario B projected a temperature increase of 0 85C by 2008 GISS temperature increase from 1960 to 2008ytd 0 412C Response This is off topic but also a great example of cherry picking The trends in annual temperature anomaly in scenario B from 1984 2007 which is when the projections started are 0 25 0 05 deg C dec 95 OLS That is equivalent to 0 57 deg C over 23 years not 0 85 The changes in the annual GISTEMP indices over the same period are 0 24 0 07 and 0 21 0 06 deg C dec Thus despite the slight over estimate of the forcings in scenario B by about 10 the long term trends are well matched and certainly within the respective uncertainties Analyses that don t take into account the differences that short term weather makes are bogus gavin 20 Rob Negrini says 7 Dec 2008 at 4 38 PM Re post 10 Considering the nature of the overall problem we re discussing Earth s climate I d add a few years of Earth Science to the list of high school courses In fact part of the AGW awareness problem may be rooted in the fact that Earth Science is usually not taught as a serious course in high school Earth Science is no more an applied area of science than is Life Science and it s as important in the long run 21 Chris McGrath says 7 Dec 2008 at 5 36 PM Joe 6 people who agree with the overwhelming data that supports global warming and agree most of that warming is caused by human activity are not climate skeptics deniers delayers contrarians Quite the reverse that is the consensus view There seem to be plenty or at least a loud minority of people who do not accept the consensus view despite the weight of evidence behind it or as Naomi Oreske puts it the multiple independent lines of evidence converging on a single coherent account See http www ametsoc org atmospolicy Presentations Oreskes 20Presentation 20for 20Web pdf 22 Anne van der Bom says 7 Dec 2008 at 6 22 PM 6 Joe Hunkins Unlike Lamarckians most critics of the prevailing concensus on climate change agree with the overwhelming data that supports global warming and many agree most of that warming is caused by human activity What worries responsible critics is how most media and most of the political interpretations have distorted the message to suggest we are at the brink of environmental collapse catastrophe I do not quite follow you if these critics agree with the overwhelming data that supports global warming then they are part of the consensus right In that case Gavin s article was not meant for them and there is no straw man What Gavin had in mind is the group of loud and irresponsible scientists journalists and bloggers that categorically reject any notion of human caused climate change and get more attention than quality of their arguments warrants See Why don t op eds get fact checked But you ve made me curious who are your responsible critics 23 James says 7 Dec 2008 at 8 01 PM Joe 6 says This is of concern because we face many extraordinary challenges and wise allocation of resources suggests that massive CO2 reduction is massively expensive and will have minimal impact for decades and perhaps centuries Your point being Scientific American October presents evidence for an extinction event at 1000ppm CO2 That s beyond our lifetimes what 100 years so lets ignore it 24 Joel B says 7 Dec 2008 at 8 21 PM Your article brings this analogy to mind You are to skeptics of AGW as the Cathlolic Church was to Galileo Luckily the facts will eventually win over models Response More likely that you are as Harold Jeffery was to plate tectonics or Fred Hoyle to the Big Bang But as you imply Nature is the only judge worth worrying about gavin 25 Ray Ladbury says 7 Dec 2008 at 8 30 PM Joseph Hunkins The fact is that we cannot preclude catastrophic consequences if we allow business as usual to continue Indeed we can show that such consequences are quite plausible and that some are an inevitable consequence of warming What is more not all ghg reduction strategies are costly many actually save money Certainly the cost of many measures pales in comparison to the trillions of dollars the American taxpayer is on the hook for wrt the Wall Street bailout and the consequences of climate change could be more dire than a financial meltdown The fact of the matter is that we need to do what makes sense to mitigate risk while at the same time improving the science to better estimate risk and developing strategies to ameliorate adverse consequences of a changing climate I do risk reduction as part of my day job It is simply irresponsible to ignore an unbounded risk 26 naught101 says 7 Dec 2008 at 8 33 PM The point is that without Lamarckianism none of the striving and achievement of a parent impacts their progeny s genetic material That was a depressing thought for many people what is the point of striving at all and hence there was a clear non scientific yearning for Lamarckian inheritance to be correct This is absurd obviously Darwinian evolution rewards success if a parent is successful in raising their young their young have a better chance of survival The only difference is that Lamarkism allows the parent any ideological definition of success where Darwinism restricts that to raising the child well this is obviously offensive to the sensibilities of numerous old school oligarchs who simply believe having shite loads of money should make their children good people while conveniently ignoring the need to nurture Which makes this a perfect analogy for climate science the fundamental reason that climate science isn t already widely accepted with large sections of the non scientific public is that it conflicts with their world view The economic fallacy of an infinitely expanding economy within a finite ecological system is being harshly tested and it will take excessive amounts of evidence to overcome the world view that holds it 27 bruced says 7 Dec 2008 at 8 35 PM As a geochemist with many denialist colleagues I find the topic of this post fascinating At least in Kammerer s case he did not have evidence such as DNA to blatantly ignore But what I find strange in the current climate are academics scientists who want potificate on AGW from a point of ignorance Just one example why does a geologist such as Prof Ian Plimmer steadfastly refuse to understand that his model for CO2 from mid oceanic ridges is just plain wrong when the carbon isotopic data is considered Surely his geology department has an isotopic expert who could explain it all to him Personally I just challenge my denialist colleagues to publish their ideas with the promise that if they can prove AGW is all wrong then great fame will follow Do others have different approaches to this problems noting that telling people that they are off the planet does not help relationships 28 Lynn Vincentnathan says 7 Dec 2008 at 8 47 PM Watson and Crick I remember reading something about them in Newsweek a few years back about how it was actually a woman scientist who made the discovery and they stole the idea from her The unrecognized lone woman science heroine But I m not sure if that s the same theory you re referring to here Anyway when I was drawing water from a well in India some years back I made the comment it must have been a woman who invented the pulley since women traditionally have drawn and carried the water My sister in law said it was a man So So Pulley To which I replied Mrs Pulley must have actually invented it then her husband got the credit Captcha Savannah honored 29 Hank Roberts says 7 Dec 2008 at 8 49 PM Scenario B Not just cherry picking cherry cloning http www google com search num 50 q 22Scenario B 22 projected 22increase of 0 85C 22 btnG Search 30 Steve Reynolds says 7 Dec 2008 at 9 26 PM First there were clear philosophical motives for supporting Lamarckism as there are for denying human effects on climate change That point can work on the other side also There are clear philosophical motives for supporting AGW as well I think it s clear the majority of contributors to this site have philosophical positions before considering climate effects objecting to modern high consumption lifestyles Is if fair to apply

    Original URL path: http://www.realclimate.org/index.php/archives/2008/12/contrarians-and-consensus-the-case-of-the-midwife-toad/ (2016-02-13)
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  • Recent Warming But No Trend in Galactic Cosmic Rays « RealClimate
    interesting to note that there is a significant correlation between the TSI and the Wolf sunspot number One critical point is then if there is a trend in the TSI why isn t there one in the sunspot number Furthermore why isn t there a trend in the GCR which also follows the solar activity And if there is a disagreement between the trends in TSI and the sunspotnumber is it then justifiable to use the sunspot number or isotope records that follow GCR to reconstruct the TSI for paelo climatic studies The implications of such disagreement are quite profound and I believe we may be looking at a very interesting topic for future research I must admit that I don t understand how Svensmark can explain how GCR can explain the recent global warming if there evidently is no trend in the GCR Even in his own papers the GCR records have been plotted and they do not exhibit trend I think we should leave it up to Svenmark to explain this 9 Ferdinand Engelbeen says 4 Jan 2005 at 10 26 AM In response to 8 indeed it seems to be difficult to have a clear picture of how the sun s acticity best is described Although all indications like sunspot group number sun cycle length TSI AA index GCR 10Be 14C all have a good correlations with each other on long term short term differences make it rather difficult to decide what is the best indication for the sun earth climate connection Fact is that if there is a connection between solar activity whatever by what mechanism and cloud cover then the small change in TSI of 0 1 1 3 W m2 at the top of the atmosphere halve of that absorbed at the surface within a sun cycle 0 25 or 4 W m2 TOA on long term since the Maunder minimum is increased with 2 8 W m2 2 of the 140 W m2 reflected by clouds or 7 W m2 since the Maunder Minimum That is some factor 4 5 over the original insolation alone which is incorporated in current climate models Response Two points First the radiative forcing of clouds is not just in the short wave and depending on where they are that can either be positive or negative Secondly if the potential cloud response is related to changes in circulation caused by the TSI or an ozone related change then it isn t an extra forcing at all it is part of the feedback and should already be incorporated in models Only if the cloud change is directly forced by some cosmic ray induced process would this be an extra forcing however the physical evidence so far of an actual mechanism for this is underwhelming gavin 10 Ferdinand Engelbeen says 4 Jan 2005 at 3 17 PM Gavin Thanks for the response As far as I know but please correct me if I am wrong current models include solar only mainly as insolation alone And consequently cloud responses of the models are included in the same way for GHG warming as for solar warming But solar has its highest direct influence in the tropics vs GHGs more toward higher latitudes And the highest variation of solar is in the stratosphere vs GHGs in the lower troposphere According to http folk uio no jegill papers 2002GL015646 pdf A physical mechanism connecting solar irradiance and low clouds might contain the following components 1 Over the solar cycle the flux of ultraviolet UV radiation varies by several and even more so in the short wavelength component of the UV This affects the propagation of planetary waves from the troposphere to the stratosphere which in turn affects weather patterns in the troposphere Haigh 1996 including the strength and location of the summertime subtropical highs Since the subtropical oceans are favoured regions for low clouds Figure 2 especially in summer such changes in weather patterns may conceivably affect low cloud cover in the manner seen in Figure 1 Thus this is a direct negative feedback of cooling low clouds on solar changes in the stratosphere not possible for CO2 but may be partly applicable for other GHGs like methane if they reach the stratosphere The second possibility as feedback to higher sea surface temperatures seems also more sensitive for solar in the tropics than for GHGs in the higher latitudes Response The point about the solar effect through variation in the UV emission on the stratosphere is an aspect of the solar terrestrial link that I personally find most interesting It is perhaps in the stratosphere upper atmosphere that we see the strongest signatures of the solar cycle There have been published some papers by Shindell Haigh and others that are worthwhile reading When putting this in context with the recent global warming then there seems to be some sticky points namely that one would expect that an intensification in the UV emission due to a more active sun would result in a warmer stratosphere not There are empirical evidence for the exact opposite a cooling stratosphere Why does the stratosphere cool when the troposphere warms I think it s also fair to say that the ozone related processes are strongly contaminated by other factors such as man made chemicals CFCs and the ozone hole rasmus 11 Mats Almgren says 5 Jan 2005 at 7 34 AM Please explain what the aa index is Response Sorry The aa index is a magnetic activity index and the reference to this is Mayaud P N 1972 The aa Indices A 100 year series characterizing the magnetic activity Journal of Geophysical Research vol 77 34 6870 6874 It is derived from from magnetic measurements near each of the poles Greenwich and Melbourne observatories but superseded by observations from Abinger Hartland and Toolangi See also paper by Lockwood et al and the site by J H Allen rasmus 12 Ferdinand Engelbeen says 5 Jan 2005 at 10 58 AM

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  • A critique on Veizer’s Celestial Climate Driver « RealClimate
    evolution can of course only be the result of all forcing factors combined including solar variability volcanic eruptions and man made aerosols not CO2 alone If all these forcing factors are taken into account in a recent model simulation the temperature evolution looks like this The black line is the average of five model runs This is not only in excellent agreement with the observed temperature changes at the surface blue stars it also correctly reproduces the observed heat storage in the oceans a strong indicator that the model s heat budget is correct The agreement of this model with observations is particularly good and perhaps partly fortuitous given that there is still uncertainty both in the climate sensitivity and in the amplitudes of the aerosol and solar forcings But our main point does not depend on that and is robust with any model and any reasonable data derived forcing the observed 20th Century warming trend can only be explained by anthropogenic greenhouse gases while other factors can explain the shorter term variations around this trend The serious scientific discussion is about the exact contribution of each factor not about identifying one single driver Is the CO2 increase anthropogenic In this paper as in the past Veizer is strangely vague on the question whether the recent CO2 increase in the atmosphere which is at the very core of global warming concerns is caused by humans He claims that the carbon cycle is piggy backing on the water cycle and he states that while CO2 may act as an amplifying greenhouse gas the actual atmospheric CO2 concentrations are controlled in the first instance by the climate that is by the sun driven water cycle and not the other way around Veizer s alternative hypothesis for 20th century global warming does appear to be the warming was caused by a celestial driver i e a change in solar activity despite the lack of observed trend and it is this warming which has increased the CO2 concentration not the other way round If this is Veizer s hypothesis and we welcome his clarification if we have misinterpreted it then this is indeed radical That humans have caused the increase in CO2 is proven beyond reasonable doubt and is generally accepted even by climate sceptics We have summarised the evidence here Not only do we know how much CO2 we emitted more than is now left in the atmosphere which means that the natural reservoirs have taken up part of our CO2 emissions rather than having released CO2 in response to a climate change That the increasing amounts of CO2 in the atmosphere come from fossil fuels was already demonstrated by isotope analysis in the 1950s CO2 increases not only in the atmosphere but also in the global oceans this is documented by 10 000 measurements and very likely in the biosphere And it would be difficult to argue that through a natural climate change CO2 has suddenly increased to values about 30 higher than at any previous time for the past 650 000 years and that this occurred by chance just at the same time as humans released more than enough CO2 to explain the rise In the light of this evidence it is difficult to believe that Veizer means to suggest the CO2 rise is a response to a natural warming So perhaps Veizer does agree that the CO2 rise is caused by humans Then it logically follows that Veizer also agrees there must be anthropogenic warming since Veizer does agree to that basic fact of physics that CO2 is a greenhouse gas see his quote above Some final remarks It is a normal essential and very valuable part of science to develop and present alternative hypotheses even if they appear unlikely at first go against the mainstream or turn out to be wrong later Without this process there would be no progress in science Hence any attempt to find an alternative explanation for the ongoing global warming is to be welcomed However to facilitate this process science has developed a culture with certain rules and standards for scientific discourse These rules include for example that all relevant data are shown if I want to make a credible case for any hypothesis I must not hide parts of a data set which do not fit my hypothesis Rather I need to discuss them In a scientific paper a selective or misleading graph may be of little consequence except for the author s reputation as scientific readers are familiar with the further data and the previous scientific discussions so they can easily judge the merits of an argument However it is in our view more serious and ethically questionable when such selective and misleading use of data is made in a press release an example from a media release by Veizer Ruhr University is discussed here Comments pop up 21 21 Responses to A critique on Veizer s Celestial Climate Driver 1 eric says 19 May 2005 at 9 35 AM Rasmus You wrote that There is the possibility of the presence of a common cause that may have affected the various isotope records representing both CRF and climate It is worth alerting our readers that this isn t merely a possibility but a well established fact For the Vostok Antarctica record shown in Figure 1 we know that the reason 10Be concentrations increase when the temperature indicator decreases is that the 10Be flux has been diluted by lower snow accumulation rates characteristic of colder climate This has been well established since at least 1989 when Jouzel and others pointed it out in a paper in Quaternary Research Every study of 10Be since that time has backed this up For example the GISP2 ice core record from Greenland similarly shows an approximate doubling of 10Be concentrations during the last glacial period when we know with 100 certainty that accumulation rates of snow had halved demonstrating that there was no change in the 10Be production rate and therefore no change in the cosmic ray flux eric 2 dave says 19 May 2005 at 1 09 PM As background to this topic a good paper to read is C02 and Climate Change by Crowley and Berner Science vol 292 5518 870 872 4 May 2001 The dispute concerns As discussed by Veizer et al there is a major discrepancy during the mid Mesozoic 120 to 220 Ma between cold low latitude temperatures deduced from the oxygen isotopic composition Π18O of fossils and high levels of CO2 and net radiative forcing The low latitude Π18O data are at variance with other climate data that show high latitude warming and an absence of large scale continental glaciation The persistent Phanerozoic decorrelation between tropical Π18O and net radiative forcing demands a more comprehensive explanation The point being that these very ancient discrepancies exist but as noted in the post follow the controversial link the correlation with CRF over geological time with temperature as measured by proxy data has not been established Certainly there is no reason to believe that CO2 as a climate driver has been undermined in any way especially on shorter time scales 3 Hank Roberts says 19 May 2005 at 2 26 PM You say The role of CRF as a driver for climate is indeed contriversial and this fact is not acknowledged in the paper Indeed controversial is academic language but to politicians this sounds like praising with faint damnation a politician is apt to assume is indeed controversial means is a hot research area rather than was asserted in one paper that used at best controversial methods to reach its claimed conclusion eh 4 Hank Roberts says 19 May 2005 at 2 28 PM Oh and check the spelling contriversial looks like either a Freudian typo or an intentional pun Maybe it s a legitimate word for contrived results I m far out of touch with academic jargon grin Response Sorry for my mispelling should be fixed now rasmus 5 Magnus says 19 May 2005 at 2 50 PM Hi I would be interested to know what you think of a model by a professor in my department Bose Nordell His main point is that all the fossil fuels we use heats up the earth since we are using trapped energy Sweden http www ltu se Thermal pollution causes global warming Nordell 2003 I m not a great fan of it Response I edited your two comments together I haven t read the paper you ref but I don t see how it can be true see http mustelid blogspot com 2005 04 global warming is not from waste heat html for my calculations William 6 Janet says 19 May 2005 at 10 12 PM Thanks for the info people Can I point out that ultimately we need to build sustainable systems if we are to consider our survival as a civilisation into the future These arguments while worthy and interesting do not effect the imperative of our current situation Burning fossil fuels and nuclear power are both limited in duration and polluting and therefore unsustainable We need to get it right and if there is any question of environmental damage we need to do it now For info on how you can personally do this easily see http www yeswecandoit org 7 Magnus says 20 May 2005 at 1 45 AM Hi again and thanks for the editing but the question is more complex then the answer on that other blog but I understand if you don t have time to look in on it Response I did take a look at the paper and William is correct This can t be right As the comment from Covey et al makes clear he is calculating a sensitivity to surface energy fluxes that is almost 100x larger than standard estimates of the climate sensitivity This is most likely because his radiative model does not have any atmospheric mixing and therefore the response to near ground fluxes is hugely overestimated The basic comparison should be with the net forcing around 1 8 W m2 from GHG solar aerosols etc and the 0 02 W m2 from thermal pollution The latter is negligible gavin Response There is some discussion of the paper finding its results implausible on the newsgroup sci env William 8 Ferdinand Engelbeen says 20 May 2005 at 3 22 AM The questions on the CRF climate link are legitimate Recent sun cloud connections have a decreasing correlation with CRF but a good correlation between low clouds and solar irradiance see figure 1 in http folk uio no jegill papers 2002GL015646 pdf Also in the 6 May 2005 Science there is an article which finds a long term link between solar intensity based on 14C variations and monsoon intensity over the past 9000 years Still while there are several theories there is no direct proof of what physically drives the sun climate connection What is clear is that the influence is larger than what is mostly included in current models as direct insolation only 9 Ferdinand Engelbeen says 20 May 2005 at 5 04 AM In response to Dave 2 One need to be cautious about the CO2 climate link too First have a look at the very long term CO2 trends of Berner and temperatures according to Scotese at http www geocraft com WVFossils Carboniferous climate html Further in more recent times there is a very close CO2 temperature relationship in the Vostok and other ice cores But there is a lag of CO2 after temperature of some 600 years during deglaciations and several thousands of years during the onset of new ice ages While the overlap during deglaciations is large which makes it near impossible to make any estimates of relative forcings during the start of the last ice age there was no overlap CO2 started to decrease some 40 50 ppmv when the temperature was already near it s minimum See http www ferdinand engelbeen be klimaat co2 temp ice html A later correction by Vimeux e a last page graph for Vostok of the deuterium temperature trend did change the amplitude of the temperature variation but not the timing The long lag of CO2 is probably not the result of timing errors between ice age and gas age in the ice core as methane more closely follows the temperature record for the timing see also the discussion at UKweatherworld This means that a change of 40 50 ppmv of CO2 has no measurable effect on temperature That doesn t mean that there is no effect at all but it is smaller than implemented in current models If one looks at all recent pre industrial time scales one sees either a lagged overlap between CO2 and temperature or a lag where CO2 follows temperature That was the case for the 8 2 ka event stomata data the Taylor Dome for last millenium temperature data not present anymore and even during recent times CO2 increase variations follow sea surface temperatures El Nià o superimposed over the industrial trend Response Ferdinand in your response to one of our earlier posts you said something about the Law Dome data having disappeared from the internet In this post you say the same about Taylor Dome I suspect you mean Law Dome but in any case I would be surprised if data from one of the National Data Center s is no longer available Can you clarify What data sources are supposedly no longer supplying the data eric 10 Magnus says 20 May 2005 at 6 26 AM Thanx for taking time I m a bit out of my field here I m an environmental engineer specializing in geochemistry but I try to read al the news on climate changes and GHG since it really interests me and btw this work by Nordel is done on his spare time and by students he has not had any resourses for research yet 11 Thomas Palm says 20 May 2005 at 11 13 AM I ve read the paper by Bo Nordell and it is junk Here is as summary I wrote in sci environment after having read it The difference between the surface of the Earth and space is 33 degrees Geothermal heat produces about 0 07 W m 2 heat and if this causes 33 degrees heating the climate sensitivity must be 470 K W m 2 Thermal pollution is 0 02 W m 2 and will thus give a heating of 0 02 470 9 K The mathematics he uses reduces this by a factor of 3 but essentially this is his argument To Nordell the sun seems to be just a small inconvenience not the source of the greenhouse effect The paper does in a way fit in this thread Just like astrophysicists starting to study climate tends to blame everything on the sun Bo Nordell who works on extracting heat from boreholes see everything in that perspective Response Thanks Thomas I ve written a bit more about this here which will point you to replies to Nordell just published in the same journal if you haven t seen them already William 12 dave says 20 May 2005 at 12 36 PM Re 9 caution over C02 climate link Yes I agree with many of your remarks The bulk of the evidence points toward CO2 as an amplifying feedback not a driver during the Ice Ages Caution is warranted for even longer time scales However the constructed CO2 temperature graph Geocarb III Paleomap in your first link is highly suspect the graph reconstruction is much too precise and does not reflect large uncertainties in the data Look at the results at CO2 as a primary driver of Phanerozoic climate for example especially figures 1 and 2 GSA Today March 2004 I can only conclude that the graph was constructed to score some political point As I said there are certainly CO2 Climate discrepancies in the Phanerozoic data Given the enormous uncertainties for continental configurations ocean currents amount of volcanism etc in reconstructing these records it would be suspicious and surprising if there were not such mismatches Reconstructing ancient carbon cycles is really hard to do and once again climate models using the best available proxy data are our best bet Most scientists working on this do conclude however that there is a reasonable 1st order approxmation between CO2 and climate Here are a couple additional papers to look at This paper by Lee Kump Reducing uncertainty about carbon dioxide as a climate driver Nature vol 419 September 12 2002 speaks to the discrepancies in the record e g middle Miocene 16ma And here s another paper The long term carbon cycle fossil fuels and atmospheric composition by Berner Finally as all this relates to the post concerning the work of Veizer no Phanerozoic correlation let alone attribution has been established with respect to CRF GCR If this premise is not established nothing further can be said about what s going on now during our unsupervised perilous experiment with Earth s climate It appears that CO2 levels have not been this high since the Eocene And as Rasmus shows it is straightforward to demonstate that CFR is not the cause of industrial age warming Response Readers interested in the question of CO 2 lag lead vs temperature should read J Severinghaus s post one of the first ones up on RealClimate here eric 13 Ferdinand Engelbeen says 22 May 2005 at 5 57 AM In response to the comment of Eric on 9 Indeed it was Law Dome not the Taylor Dome I had written that from memory but as my memory is not anymore what it was 40 years ago What I meant was a graph on the Internet showing the Law Dome ice core CO2 variations lagging the temperature variations with some 50 years with 10 ppmv K similar

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  • The lure of solar forcing « RealClimate
    for any confusion 5 Pascal says 15 Jul 2005 at 4 38 PM Hi Gavin Can you explain the correlation that should exist between NAO and solar cycle There are some forecasts concerning a cold winter 2005 2006 in western Europe These forecasts for example Met Office UK come from a link between SST and winter NAO then between winter NAO and temperature negative anomaly Some people see a link between solar cycle and NAO They say that since we have a minimum solar activity between 2005 2007 we get negative NAO and temperature anomaly I tried to see any correlation between the solar cycle and the NAO indice but the two curves seemed completely independant Can you give some informations about this Response The mechanistic theories for why there should be link involve either stratospheric influences on the NAO similar to the process that leads to a stronger winter NAO after big volcanoes for instance or changes in tropical SST or both A tropical SST link would explain why the signal is strongest with a 10 to 20 year lag of the long term changes Waple et al 2001 but the noise in the NAO record could mean that you only see significant changes after long term averaging There is still a lot of work being done on this but I wouldn t anticipate much of a significant change in NAO over 2005 2007 since there is a lot of noise and a lot of other influences not least greenhouse gases which with either mechanism provide an opposing tendency gavin 6 Dragons flight says 16 Jul 2005 at 1 53 AM One of the better views of long term solar activity is available at http en wikipedia org wiki Image Solar Activity Proxies png Note that Beer et al s beryllium data unfortunately end right around the time that modern neutron counter experiments say that it should have leveled off 7 GeniusNZ says 16 Jul 2005 at 6 16 AM Steve Latham I think there is a pretty complex dynamic governing that relationship Still on balance I agree they will be MUCH greater than 5 and the best journals will probably have more of them than second tier journals 8 Lynn Vincentnathan says 16 Jul 2005 at 11 03 AM I differ with 2 7 Good theory is still an important requirement of science so that should moderate the publishing of wacko false positives However I did notice when doing research in the early and mid 90s that The New Scientist tended to publish more sensational articles than Science or Nature Since AGW did not reach scientific certainty in studies until 1995 that meant The New Scientist was publishing more articles more assuming AGW validity than the somewhat more scientifically cautious journals And I think that s good to have a least one journal that does that even if they might possibly publish more contrarian research that doesn t pan out later The other point is that AGW is obviously not your normal science topic so publishing research that reconfirms AGW is in itself sensational would keep the readership interested subscribing I know that the mainstream media is afraid to touch even bonafide mundane studies that reconfirm AGW because of their sponsors or fear of eliciting a slew of negative responses from contrarians I m thankful that most CC scientists are continuing to do their research and publish honest reports in the face of threats wearisome bogus contradictions When they entered science they probably didn t realize they d be called on to be troopers as well 9 Blair Dowden says 16 Jul 2005 at 11 35 AM Hi Gavin In a different discussion I asked you to explain the fall in temperature between 1940 to 1970 Your response was Response The IPCC itself doesn t have any models however the results from the this GISS model have been submitted to the archive run by IPCC so that they can be considered for the next assessment report AR4 With respect to your question the slight cooling trend seen in the results is a function of a combination of increasing aerosols significant volcanic activity especially in the early 1960s and a plateau in both the greenhouse gas forcing and solar Together that produces the blip that you can see Once internal variability is also taken into account the trend goes from near zero to negative over the different realisations gavin I still don t understand the plateau in greenhouse gas forcing but you also seem to be suggesting changes in solar activity as a significant driver of climate Do you have figures with uncertainties about how much changes in solar forcing affect climate I would really like to know how relatively important this is Response I ve made it clear that I think that the solar variations are indeed a factor in driving climate change though my opinion is that it is a relatively small factor over the last century It s difficult to assign a specific number because of the uncertainties in solar and other forcings particularly early in the century and in even working out the correct calculation to do i e since there are multiple positive and negative forcings it will depend on how you group them If you lump them as natural forcings vs anthropogenic forcings you end up with something like 20 natural from 1900 to 1940 note that I haven t done this calc exactly and even less since then There is the potential for some wiggle room there though You can do the calculations yourself based on the forcing fields available at http www giss nasa gov data simodel F indiv data txt gavin 10 Klaus Flemloese Denmark says 16 Jul 2005 at 1 55 PM It is my understanding that a consensus has arrived on the influence of the sun on the climate This originates from an increased knowledge of the variation in the sun Please refer to the following link from where I have copied the most important results http www mpg de english illustrationsDocumentation documentation pressReleases 2004 pressRelease20040802 How Strongly Does the Sun Influence the Global Climate Studies at the Max Planck Institute for Solar System Research reveal solar activity affects the climate but plays only a minor role in the current global warming Two scientists from the MPI for Solar System Research have calculated for the last 150 years the Sunâ s main parameters affecting climate using current measurements and the newest models the total radiation the ultraviolet output and the Sunâ s magnetic field which modulates the cosmic ray intensity They come to the conclusion that the variations on the Sun run parallel to climate changes for most of that time indicating that the Sun has indeed influenced the climate in the past Just how large this influence is is subject to further investigation However it is also clear that since about 1980 while the total solar radiation its ultraviolet component and the cosmic ray intensity all exhibit the 11 year solar periodicity there has otherwise been no significant increase in their values In contrast the Earth has warmed up considerably within this time period This means that the Sun is not the cause of the present global warming These findings bring the question as to what is the connection between variations in solar activity and the terrestrial climate into the focal point of current research The influence of the Sun on the Earth is seen increasingly as one cause of the observed global warming since 1900 along with the emission of the greenhouse gas carbon dioxide from the combustion of coal gas and oil Just how large this role is must still be investigated since according to our latest knowledge on the variations of the solar magnetic field the significant increase in the Earthâ s temperature since 1980 is indeed to be ascribed to the greenhouse effect caused by carbon dioxide says Prof Sami K Solanki solar physicist and director at the Max Planck Institute for Solar System Research My comments As I read this paper the debate on the impact of the sun on the climate is closing Is this correct I will be pleased if some will be able comment on this 11 Terry says 16 Jul 2005 at 7 35 PM Begin quote Astute readers will notice that there is a clear problem here The widespread predisposition to believe that there must be a significant link and a lack of precise knowledge of past changes are two ingredients that can prove err scientifically troublesome Unfortunately they lead to a tendency to keep looking for the correlation until one finds one When that occurs as it will if you look hard enough even in random data it gets published as one more proof of the significant impact that solar change has on climate Never do the authors describe how many records and how many different smoothing methods they went through before they found this one case where the significance is greater than 95 Of course if they went through more than 20 the chances of randomly stumbling onto this level of significance is quite high The proof that this often happens is shown by the number of these published correlations that fall apart once another few years of data are added cosmic rays which are modulated by solar activity and cloudiness for instance Sometimes even papers in highly respected journals fall into the same trap End quote A superb post which very persuasively throws into doubt claims that solar variation can explain recent temperature changes I applaud your courage since this is the very same logic that has thrown so much doubt on Mann s results and very neatly summarizes why Mann s work has drawn so much fire You have gained a great deal of credibility in my eyes at least Response I m glad you re happy I don t see the connection with Mann et al though I am talking here about spurious correlations being trumpeted as proof of an effect The work of reconstructing past climate changes though it uses correlations between multiple proxies and climate is subject to validation and in and of itself is not proof of any effect be it solar or greenhouse gases or whatever gavin 12 JS says 17 Jul 2005 at 12 46 AM I also saw the connection that Terry suggested I do not necessarily see it as some sort of slam dunk refutation of Mann or whatever so hold any defensive reflexes just for now I will try and explain it as I see it Mann showed that there was a correlation between proxies and global temperature over the past 100 or so years Further investigation has suggested that this is primarily a correlation between some Bristlecone pine ring widths or densities and global temperature they are the dominant element of Mann s PC1 and in their absence there is very little correlation MM and subsequently Wahl and Amman have shown this effect The validation you refer to is an out of sample forecast test that does not overcome the problem that correlation does not prove causation Furthermore the Mann studies and those that followed are essentially bivariate regressions which map between temperature and the distilled essence of the proxies the point of the PC analysis Importantly there is no multivariate investigation in Mann e g a regression of the PC of the proxies on temperature and rainfall and CO2 concentrations to name a few Thus the concern about spurious correlation still exists there could well be omitted variables bias Furthermore temperature is a strongly trending series over the instrumental period This leads to concerns that there may be problems caused by non stationarity of the series which detrending or similar processes does not cure This reinforces concerns that it may be a spurious correlation using that term technically to refer to I 1 series The problem then becomes that if the correlation shown over the past 100 years or so is spurious then any reconstruction is flawed Doesn t necessarily mean its so but the exact same concern you discuss with respect to solar input does definitely affect Mann et al et al Response If Mann et al was simply based on a correlation you may have had a point However there are clear validation steps in the MBH methodology i e the proxies are matched over the period 1900 to 1980 and then validated against the the earlier period 1850 to 1900 to see if there is any predictablity this is the step missing from most solar correlations Only the proxy networks that valdiate in this way were used in the reconstruction Note also that the issue with the bristlecone pines which was first brought up by Mann et al 1999 only affects the reconstruction between 1400 and 1490 because of the sparsity of data for that period gavin 13 Jeff Norman says 17 Jul 2005 at 4 15 AM I will offer up my apologies in advance because this is probably the wrong thread to ask this however In the paper Global Surface Temperatures over the Past Two Millennia by Michael E Mann and Philip D Jones Geophysical Research Letters Vol 30 No 15 1820 August 2003 how are the uncertainties for the Northern and Southern Hemispheres Fig 2a b calculated http www ncdc noaa gov paleo pubs mann2003b mann2003b html The uncertainties for the NH and SH appear to be the same and they appear to remain constant over the entire 2000 years of the reconstructions This seems to be counter intuitive because 1 The SH has far fewer records which suggests a greater uncertainty as suggested in the abstract and 2 I would have thought the uncertainty would increase with time in the past from the present Any help understanding this would be greatly appreciated JeffN Response This paper tried to use a smaller number of long term records to make a uniform reconstruction MBH on the other hand used different networks for different periods hence the error bars changed as the networks get smaller further back in time In Jones and Mann the errors are constant because the network is constant gavin 14 Ferdinand Engelbeen says 17 Jul 2005 at 5 52 PM Gavin You may have noticed that I am a fan of enhanced solar influence on climate than currently included in climate models Let me explain this again About past temperatures and sensitivity for solar forcing First there are more indications that the MWP and the LIA show larger temperature variations than what is found by different multi proxy reconstructions Mann Crowley even Moberg Also beyond the North Atlantic See the stalagmite data from China with variations of 4 3 ºC compared to current annual temperature Also coral data of the Great Barrier Reef where the seawater temperature varied 0 5 1 ºC compared to today in the past centuries And not to be forgotten borehole data which show a full 1 ºC change globally in the past five centuries It seems to me that most multi proxies except Moberg rely too much on tree ring data for one can question the reliability as temperature indicators If there was more climate variation in the past then models should be adjusted for larger sensitivity towards natural variability especially solar About models and solar forcing GCM s give some rather good simulation of past temperatures But there are problems with volcanic influences As the Shindell paper shows the influence of volcanic is within the modelled unforced variability except for Europe where it is outside but with the wrong sign compared to proxies thus probably overestimated in the model in question An investigation by Stott ea to check the attribution of different forcings in the Hadcm3 model did find an underestimate of solar factor 2 within the constraints of the model like fixed influence of aerosols It is found that current climate models underestimate the observed climate response to solar forcing over the twentieth century as a whole indicating that the climate system has a greater sensitivity to solar forcing than do models The largest problem in current climate models is the feedback from cloud cover That is responsible for most of the broad 1 5 4 5 ºC range in sensitivity for a CO2 doubling between different models But there is a direct connection between cloud cover and solar irradiation which still holds until now last data 1999 During a sun cycle the global cloud cover changes with 2 good for a change of several W m2 depending on type of clouds and region far higher than the effect of insolation change as result of the sun s energy variation The negative correlation between low cloud cover and solar irradiation is high and significant see Kristjà nsson ea As far as I know not one of the current climate models includes the cloud cover response to the solar cycle neither to longer time changes in solar activity About solar variability and climate indications Solar variability is found in tree rings of Northern Europe see page 3 of the 5 MB record while there is no visible influence of increased GHGs The summer temperature indication by tree rings in Finnish Lapland is decreasing in the period 1950 2001 see page 14 of Pages News But this also may be an indication that the use of tree rings as past temperature indicators is not free of problems About 14C 10Be reconstructions and climate From the Mangini ea paper The highly significant correlation with delta 14C underlines the important role of solar forcing as a driver of Northern Hemisphere climate during the past 2 millennia while you wrote that the explained variance with the 14C record is only 5 No matter that solar activity in the past 60 years has never been as high in the past 8 000 years It s level since the 1940 s is constantly higher

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  • Did the Sun hit record highs over the last few decades? « RealClimate
    library FAQs evolution blfaq evolution evidence12 htm Comments There are two main aspects of a living earth the cirrus cloud part and the ocean part The cirrus clouds in pre cellular earth would have contained nucleotides in such manner as they would 1 replicate and 2 have an electrical to mass meaning IOWs if rain feedbacks convection feedbacks caused nutrients to be available on the ocean surface below such that the nucleotides could both replicate and replicate with a meaningful mass and charge you would have a good feedback As always there was survival of the individual nucleotide complex and survival of the entity the living earth Below in the oceans the nucleotides would contain chemistry over chaotic diffusion of chemicals but that containment was probably not all that significant on conductivities like cellular life is today Appreciate that the oceans are too saline for the China paper cloud parasol asymmetries to occur in DC fields between ionosphere and ocean Junk DNA was anything but junk to cirrus cloud formations in pre cellular earth The function of the DNA was not to produce proteins or regulate or translate them but rather the nucleotide function was simply to provide an electrical feedback to convection processes that occur w cirrus clouds that can trap heat compress air and cause rain over ambient lifeless winds and climate inputs Indeed the purpose is closely seen in the electropherisis that leads to appreciating that they exist The cloud parasol feedback is quite powerful depending on the size shape mass and charge of the complex and additionally because of phase change energies on the DNA particles forming or not in cloud nucliation processes bring to cloud dynamics significant forcings See this Tinsley article http www utdallas edu dept physics Faculty tinsley Tin rev pdf If solar variability due to heat was all that mattered then life could not have design 2 Armand MacMurray says 4 Aug 2005 at 2 40 AM Thanks for a very nice exposition of some of the issues involved in estimating past solar activity I understand that the Group sunspot number extends further back than the Wolf number but given the striking disagreement between the 14C Group numbers around 1780 Fig 1 would it be better to use the Wolf number 3 Mike Doran says 4 Aug 2005 at 11 14 AM 2 I don t think the sun mattered much in the Little Ice Age either the way it is currently framed I am much more impressed with a gravity wave theory put out by Charles Keeling from Scripps who just passed away See http www pnas org cgi content full 070047197 The data merely lacks causal mechanism as an explaination Even the Soon paper work falls short on cause for the sun and admits that there is not proper appreciation of what the earth takes from the sun as opposed to what the sun gives and that mystery is more appreciated by looking at essentially what is going on from an EMF standpoint between earth and the sun In that context gravity waves roil and depressurize the oceans and that then leads to outgassing of CO2 it comes out of solution in the ocean and bubbles to the surface and their given capacitive couplings impacting pH runs back to ion form which then impacts conductivity The conductivity changes impact cloud microphysics and heat trapped or released out into space So you could have a paradox of more sun heat coming to the earth and the earth taking less of that heat it gets released out into space or turned into kinetic energy like a tropical storm all because of the ELECTRICAL features impacting earth including some impacts that are not related to the sun like moon gravity waves Presently I am looking at a solar wind speed under 500 that seems to correlate with tropical storm formation One theory for this is while solar activity leads to increases in high freq light and that light splits O2 into ozone and hence increases the ions for couplings between ionosphere and ocean at the same time particles of protons come to be attracted to opposing charges and the whole organization of van Allen belts electron shell proton shell upper ionosphere lower ionosphere gets disturbed and prevents formation of nice coupled states between ionosphere and ocean above tropical storm eyes But then the other thing going on is those same protons run to the closing isobars of the earth EMF away from the tropics and there reduce ozone and create over time a concentration of ozone over the tropics thereby increasing the intensity of the ITCZ and increasing tropical storm probabilities as the wind then wanes under 500 These are the kinds of very complex space weather discussions that need to occur and at the end of the day CO2 is DEPENDANT on these solar events as CO2 is ELECTRICAL from a conductivity standpoint in the oceans connected to surface lows and outgassing and ocean surface ion counts 4 Stephen Berg says 4 Aug 2005 at 3 57 PM Re 3 In Brian Fagan s The Little Ice Age he cites several paintings and diaries which have stated that the LIA was a period of dull skies i e lack of bright sunshine and increased cloudiness The Keeling oceanic tidal cycle article you site deals with 1 800 year cycles and not 200 or 300 year cycles Keeling also mentions that solar cycles i e Milankovitch Cycles are multi millennia scale As the LIA lasted only a few centuries wouldn t the oceanic tidal cycles be either irrelevant or at least not individually responsible for the occurrence of the LIA Also as it relates to the AGW discussion since the oceanic tidal cycle has such a long duration wouldn t this cycle be irrelevant since AGW has only taken hold over the last 150 years and has such a high rate of temperature increase As for the whole electrical and space weather business none of that makes much sense in a global context The theories that moon gravity waves ocean ionization and proton electron changes could somehow trigger an increase in temperature seems to be quite bizarre to me Response It is important to remember that paintings and diaries are anecdotal for instance Bruegel s Hunter s in the Snow is often cited in such a context but often neglected is that the fact that this was a a fictional scene and b part of a series of seasonal paintings The Harvesters for instance shows a very sunny and pleasant day Is that proof of warmer autumns I don t think so gavin 5 CharlieT says 8 Aug 2005 at 5 45 AM I m struggling with the earth bound C14 production series Is the series shown in Gavin s lure of solar forcing plot at a different stage of geomag dilution correction to the series shown in Fig 2 of the Nature Arising comment I m looking at the relative size of the 1780 s spike They seem v different but perhaps its detrending etc or just an error 6 Harry Francis says 8 Aug 2005 at 10 00 AM Might the global warming simply be due to the daily collection of space dust suggested at over 150 million tons each year With increased mass are we not slowly attracted closer to the sun 7 Andrew Dodds says 8 Aug 2005 at 10 31 AM Re 6 Several astronomical factors affect the climate of the earth the Sun gets brighter over time as it moves along the main sequence and the Earth gradually drifts further away from the sun as the mass of the sun drops Solar wind nuclear conversion Space dust should have zero net effect since on average it should have the same orbit as the earth to start with However it has to be realised that the above effects work on timescales of a minimum of 10 million years and are only detectable at timescales longer than that If astronomical factors were capable of producing a trend on human timescales we d have baked or frozen a long long time ago 8 Raimund Muscheler says 9 Aug 2005 at 12 45 PM Re 5 The 14C production rate record shown in lure of solar forcing basically agrees with the record shown in this discussion The difference is I The older calculation Muscheler ETH PhD2000 Muscheler et al QSR 2005 covers the Holocene period using the IntCal98 D14C record II The new calculation Muscheler et al Nature 2005 uses the annual 14C record measured by Minze Stuiver et al In addition we included the Suess effect the dilution of 14C in the atmosphere due to the combusion of 14C free fossil fuel This is important for the period from 1850 to 1950 yr AD and allowed us to connect the 14C production series to the instrumental measurements of the galactic cosmic ray flux Please note that in general the different 14C production rate estimates agree well Minze Stuiver was the first to do these kind of calcuations The results depend only slightly on the applied carbon cycle model The 14C production rate minimum around 1780 yr AD high solar activity follows from a strong minimum in the D14C data from the northern hemisphere it is visible in the annual D14C data and in the new IntCal04 calibration record However the minimum is smaller in the D14C record from the southern hemisphere Therefore I think the peak around 1780 yr AD rather overestimates solar activity The 10Be record from Antartica indicates that the 1780 yr AD maximum is on a similar level as around 1950 yr AD Within the uncertainties this is still in agreement with the 14C data 9 Mike Doran says 9 Aug 2005 at 10 37 PM http groups yahoo com group methanehydrateclub message 2483 10 Alec Rawls says 10 Aug 2005 at 2 04 AM Nice post but the conclusion solar activity has not increased since the 1950s and is therefore unlikely to be able to explain the recent warming would seem to be a non sequitur What matters is not the trend in solar activity but the level It does not have to KEEP going up to be a possible cause of warming It just has to be high and it has been since the forties Presumably you are looking at the modest drop in temperature in the fifties and sixties as inconsistent with a simple solar warming explanation but it doesn t have to be simple Earth has heat sinks that could lead to measured effects being delayed and other forcings may also be involved The best evidence for causality would seem to be the long term correlations between solar activity and temperature change Despite the differences between the different proxies for solar activity isn t the overall picture one of long term correlation to temperature Response You are correct in that you would expect a lag however the response to an increase to a steady level of forcing is a lagged increase in temperature and then a asymptotic relaxation to the eventual equilibirum This is not what is seen In fact the rate of temperature increase is rising and that is only compatible with a continuing increase in the forcing i e from greenhouse gases gavin 11 Ilya Usoskin says 10 Aug 2005 at 4 24 AM The commentary by Raimund Muscheler presents quite a one sided view on the problem It is based on their Comment to our paper in Nature 2004 However next to their Comment our official reply Solanki et al Nature 436 E4 E5 doi 10 1038 nature04046 2005 has been published which is ignored in Muscheler s commentary We urge the reader to get acquainted also with our point of view before making any conclusion Muscheler et al 2005 tried to reproduce our reconstruction Solanki et al 2004 of solar activity from 14C but in a different way and obtained a different result Note that the details of how the results were obtained have not been published Accordingly their computation cannot be repeated and verified independently In contrast our approach has been developed and verified in a number of papers Solanki et al Nature 408 445 2000 Solanki et al Astron Astrophys 383 706 2002 Usoskin et al J Geophys Res 107 A11 2002 Usoskin et al Phys Rev Lett 91 21 211101 2003 Usoskin et al Astron Astrophys 413 745 2004 Solanki et al Nature 431 1084 2004 Usoskin and Kromer Radiocarbon 47 1 31 2005 which contain full details of the method Muscheler et al did not find any error in our method while we brought to light a serious flaw in Muscheler et al 2005 which causes the disagreement between his and our result Briefly their method produces only relative variations of cosmic ray flux In order to discuss the absolute level of reconstructed solar activity they normalized it to the measured values during 20th century a free parameter of the model Unfortunately when performing the normalizing procedure they made use of an inappropriate data set from which the long term trend has been implicitly removed see details in Solanki et al 2005 This resulted in a distorted long term trend in their reconstruction When using the correct data set called alternative by Muscheler et al 2005 they obtained the results which are very similar to ours as the purple curve in Muscheler s Fig 1 is close to our solar activity reconstruction from 14C see Solanki et al 2004 All other curves in Muscheler s Figure are affected by this normalization flaw which is seen as a constant offset between the curves all curves are parallel to each other before 1950 Actually this large difference of about 300 MV between purple and green curves serves as their model uncertainties Briefly Muscheler using a different unpublished and unverified method obtained a result which differs from our results We don t think that just this difference provides a substantial basis to claim that our results are wrong 12 Richard Harvey says 10 Aug 2005 at 1 32 PM Couldn t the question of attributing the recent warming to a solar influence be answered by looking at the 3D distribution of the signature of that warming For instance the nighttime temperature minimums have increased at about twice the rate of daytime maximums If the sun had been the main cause of global warming this trend should have been reversed i e daytime maximums increasing faster From this fact alone the sun just can t be the cause Comments 13 Brent Putnam says 10 Aug 2005 at 2 34 PM John Finn made some interesting observations in his post Unfortunately that was lost because of the technical glitch Fortunately I found them in a cached copy Here they are complete with responses from Mike and Gavin Response It is important to remember that paintings and diaries are anecdotal Response Comments such as yours which cherry pick the available evidence see below we point out a few glaring examples to make the more general point We could have gone on to the point of disinforming rather than educating our readers will not be tolerated on RealClimate We let this one through but other similar future postings will be deleted mike Absolutely right So called evidence from Art and Literature cannot be accepted as an indication that a Little Ice Age existed and there is therefore no proof whatsoever Well apart from the Central England Temperature record http www usefulinfo co uk images cetann gif which shows that temperatures 10 year running mean in the late 17th century were 2 degrees colder than they were just 40 years later but that s obviously a local blip which we can ignore Response For most of the pre 20th century 1650 1900 interval the CET record shows very little change at all Do you really believe that citing one isolated 30 or so year period of cooling within that record that occurs during the late 17th century defines The Little Ice Age You should read the background material already provided on RealClimate especially our correction of some common myths and half truths see myth 2 mike Ok perhaps we shouldn t forget how some Keigwin chap showed that the Saragossa Sea was 1 deg colder 400 years ago Response Unfortunately you seem to have conveniently forgotten that Keigwin and Pickart published a paper in Science just a few years later in 1999 pointing that the appparent cooling actually the oxygen isotopic signal in question isn t entirely temperature it is salinity as well so the quantative 1 deg cooling estimate you cite is not actually reliable in the Sargasso Sea is diametrically opposed by a substantial warming at the same time in the Laurentian Fan region of the North Atlantic off the coast of Newfoundland The pattern of cooling in the tropical North Atlantic and warming off Newfoundland as Keigwin and Pickart note is consistent with a dominant North Atlantic Oscillation NAO signature to the climate variability in this region during the MWP LIA alternation Modeling work published by members of the RealClimate group supports this conclusion See e g this review paper Schmidt et al 2004 where the response of a climate model to estimated past changes in natural forcing due to solar irradiance variations and explosive volcanic eruptions is shown to match the spatial pattern of reconstructed temperature changes during the Little Ice Age which includes enhanced cooling in certain regions such as Europe This patterns is shown to be in large part a product of an extended negative phase of the NAO The model also matches well the smaller estimated hemispheric mean changes which typically represent a cancellation of larger regional patterns of warming and cooling associated with processes such as the NAO mike http www sciencemag org cgi content abstract 274 5292 1503 rbfvrToken 23557ca793ff66d4935b12190faace3cf3b08275 And while we re

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  • Another study on solar influence « RealClimate
    et al 1995 and due to their model assuming a lagged response A link to the WM2003 paper is http pubs giss nasa gov docs 2003 2003 WillsonMordvinov pdf see Fig 2 When it comes to statistical significance and hypothis testing I do not recall whether the trends have been tested against a null hypothesis but the short term variability is quite high compared to the trend in the WM2003 case and the series is short so I doubt the trend is significant just by eyeballing rasmus 4 Nicola Scafetta says 4 Apr 2006 at 1 29 PM Dr Benestad has written an interesting critique to our paper Geophysical Research Letters Scafetta West S W In my opinion Dr Benestad s critique is very poor for several reasons I cannot fully and extensively explain here But I will give few examples A reader of RealClimate wrote me asking to reply publicly to the Dr Benestad s critique on this open web site While I would have preferred a more appropriate scientific forum for a discussion I believe that I should not disappoint this reader as well as other readers of RealClimate org that might be confused by Dr Benestad s statements Response I appreciate Dr Scafetta s response and I think that a blog like RealClimate is an appropriate forum for discussions like these rasmus First critique mysteries about the temperature patterns About our supposed inconsistencies Dr Benestad starts The S W temperature signal when closely scrutinised their Fig 3 starts at the 0K anomaly level in 1900 well above the level of the observed 1900 temperature anomalies which lie in the range 3K T 1K in Fig 1 So where does the mysterious 0K anomaly level in 1900 come from Well Dr Benestad should look more carefully at the Y label of our figure 3 In fact we are plotting the function f t T sun t T sun 1900 What is the value of the function f t in 1900 Well we have f 1900 T 1900 T 1900 0K right So the first mystery is easily solved The answer is that in figure 3 we are plotting the solar induced temperature anomaly relative to the year 1900 and not an anomaly relative to the mean 1960 1990 as it is usually done for the temperature as fig 1 show In figure 3 we plotted the function f t T t T 1900 because in this way it is easier to visually estimate the warming induced by the sun since 1900 that is all Similar explanation clarifies the difference about the amplitudes of the peaks in the interval 1945 1960 that in figure 3 is at 0 3K while in figure 1 is at 0 12K Response OK but regardless whether the anomalies are with respect to 1900 or any other period the curves do not match rasmus About the time shift of the peaks between 1945 and 1960 This is a more interesting issue It can be explained in several ways One way is that the peak we found around 1960 in the solar temperature induced signal is due to the fact that Leanâ s solar irradiance proxy reconstruction we have used presents such a peak around 1960 however other TSI proxies present such a peak in 1945 such as the Hoyt and Schatten s reconstruction In fact in literature there are several TSI proxy reconstructions and they are all different Some of these reconstructions are here http www grida no climate ipcc tar wg1 fig6 5 htm Thus the reader can easily realize that there is a controversy about when the sun s peak occurred whether in 1945 or in 1960 We used Lean s TSI because it is a good average among the several reconstructions but we never intended that Lean s reconstruction is perfect in every pattern nor we were interested in our paper to discuss in detail the 1945 1960 solar peak controversy Second critique further mysteries about sensitivities Dr Benestad talks about climate sensitivity Stefan Boltzmann law non linear physics and I think he makes a great confusion Well let us clarify the issues We are referring to parameters Z as climate sensitivity transfer parameters I stress the adjective transfer because it is what Dr Benestad did not notice in our paper Our climate sensitivity transfer parameters do not have anything to do with what in the climate textbooks is referred to as climate sensitivity parameters that are calculated in a different way In other words we are using a different definition Dr Benestad has not realized it and thought it was a mistake Dr Benestad might not like our definitions but he cannot criticize them because they are definitions and must be taken for what they are To better explain this first let us look more carefully at the Stefan Boltzmann law Dr Benestad states The textbook formulae for a simple radiative balance model is F 1 A 4 s T4 where s here is the Boltzmann constant 5 67 x 10 8 J s m2K4 First of all Dr Benestad s equation is wrong The right equation is 1 F 1 A 4 I s T 4 Response This is correct Thanks for pointing this out rasmus where A 0 3 is the albedo I 1365W m 2 is the solar irradiance s 5 67 x 10 8 W m2K4 is the Stefan Boltzmann constant T 288K is the average Earth temperature The rationale of the above equation is easy the term F 1 A 4 I refers to the amount of solar irradiance that is absorbed by the earth surface after considering that 30 of the input irradiance I is reflected away by the albedo and what remains spreads on the spheric surface of the earth the factor 4 The second part of the equation is the Stefan Boltzmann law Now let us calculate both sides of the above equation 1 with the above values we obtain 2 1 A 4 I 239 W m 2 3 s T 4 390 W m 2 Why is there such a big difference What kind of mystery is this Well the answer is simple the Stefan Boltzmann law works for a black body while as everybody knows the Earth is not black Response The black body radiation law still applies albeit in a more complicated settings there are many other processes at work Thus it would be correct to say that the Earth is not just a black body rasmus Thus Dr Benestad s equation above even after my correction cannot be applied to the Earth climate system But let us make some further interesting calculation Let us suppose that the earth is a black body and use the Stefan Boltzmann law 1 to calculate the hypothetical temperature T given the solar input of I 1365W m 2 We get 4 T 255K black body approximation Now let us reason a little bit The black body approximation gives T 255K this would mean that everything on earth would be frozen because ice melts at T 0C 273K Now the mystery is why the climate is much warmer and the average temperature of the earth is 288K almost 33K higher The answer is easy the atmosphere of the earth is full of so called green house gases water vapor above all CO2 CH4 etc that warm the atmosphere to a temperature of T 288K In fact green house gases cause a powerfull positive feedback to solar input and warm the climate to the actual 288K I believe that any reader has now understood where the problem is with Dr Benestad s argument The Stefan Boltzmann law does not take into consideration the feedback warming effects of the green house gases so it cannot be used to study the real earth climate So we have to use a different approach There are two possibilities 1 using a climate model this implies a perfect knowledge of all involved climatic mechanisms and nobody has such a knowledge yet 2 use a simpler phenomenological approach We adopted the second approach and use a transfer methodology that defines I stress defines at equilibrium the value as 5 Z eq T I 288 1365 0 21 K W m 2 Response This implies a linear response between F and T although you do not state so Furthermore this estimate does not involve a small interval over which the response can be aproximate as being linear Thus I do not believe that this transfer function can be applied rasmus A curiosity what would Z eq be if the earth were a black body and the Stefan Boltzmann law worked The answer is easy with a little algebra it is 6 Z eq T I 1 A 4 sT 3 0 13 K W m 2 black body approximation Thus why is the value in 5 larger than the value in 6 Answer because in 6 according to the black body approximation positive feedbacks due to the greenhouse gas effects do not exist Dr Benestad states It is well known that these feedbacks are highly non linear Let s just mention the ice albedo feedback which is very different at hypothetically e g 100K surface temperature with probably snowball earth and at 300K with no ice at all In this statement there is much confusion due mostly to the fact that Dr Benestad writes much but does not do any calculation Our estimates and calculations are supposed to study solar effects on the climate within a very small temperature interval of approximately 1K around the average of 288K In this small interval our linear like assumption in Eq 5 is perfectly fine In fact if in Eq 5 instead of T 288K we put T 289K or T 287K the changes are very small Also about the ice albedo feedback within 1K temperature oscillation the albedo will change of let us say 10 so for an increase of 1K the albedo will decrease from A 0 3 to A 0 27 But putting the latter value in Eq 6 the value of Z would change of approximately 1 3 which is a very small change and can be neglected Moreover we have never stated that the value Z eq is linear or constant at any temperature from 100K to 300K as Dr Benestad claims Z eq is the equilibrium climate transfer sensitivity to solar input at a given temperature that in our case is T 288K and at a given solar irradiance I 1365W m 2 Of course Z eq will significantly change for a large change of the temperature So Dr Benestad should not misquote us to build his argument we never said that Z eq is linear or constant with temperature at any value of the temperature Dr Benestad states In their formula for the calculation of the sun related temperature change the long term changes are determined by Zeq while their climate transfer sensitivity to slow secular solar variations ZS4 is only used to correct for a time lag The reason for this remains unclear Perhaps the reason is unclear to Dr Benestad is because Dr Benestad should have read our paper more carefully He would have realized that the use that we make of Z eq is very limited It is only a constant that is taken off when in Fig 3 we calculate f t T t T 1900 Contrary to what Dr Benestad states we have adopted Z S4 as our transfer climate sensitivity for the slow solar secular variation and not only for correcting a time lag as he states This is clearly stated in our paper in Eq 3 Again Dr Benestad should not misquote us to build his argument Third critique solar climate transfer sensitivity or climate sensitivity Dr Benestad states They take the ratios of the amplitude of band passed filtered global temperatures to similarly band passed filtered solar signal as the estimate for the climate sensitivity This is a very unusual way of doing it but S W argue that similar approach has been used in another study However it s not as simple as that calculating the climate senstivity The reply to this comment is simple As we have said in our paper and above in this reply we are not using the tradition climate sensitivity definition commonly found in the climate textbooks but we have introduced a novel sensitivity called solar climate transfer sensitivity The adoption of the word transfer should mark the difference Because we are using a different definition than what Dr Benestad s knows Dr Benestad should first quote correctly our paper and then simply do a little afford to understand our definition and accept it In fact we are free to use the definition that we wish and do the calculation in accordance with it A definition is a definition and cannot be criticized by making a different definition Response There is no guarantee that such definitions really are representative of the natural processes I argue that it is not rasmus About our estimates of the climate transfer sensitivity to solar variations at 11 years and 22 years Dr Benestad makes again a great confusion by misquoting and misunderstanding our paper Let us see why In fact our finding is based indeed on three different ways to do the calculations In our 2005 paper we present a way based on wavelet band passed filtered signals but we also referenced other two works one by Douglass and Clader 2002 and another one by White et al 1997 Douglass uses a multivariate linear regression analysis that explicitly takes into consideration Enso signal and volcano signal White et al adopt a Fourier band pass filter on an interval 1900 1991 All three methods agree with what we have called transfer sensitivity to 11 year cycles Z11y 0 11 0 02 K W m 2 Thus our conclusion was that the phenomenological climate transfer sensitivity to the 11 year solar cycle is likely given by Z11y 0 11 0 02 K W m 2 The above finding reinforces our interpretation In fact Dr Benestad reasons in general while we reason in the particular case we are analyzing where the techniques work correctly also because in 1980 2002 the ENSO oscillations are quite fast almost 2 4 years and are cut off by the filter and the two volcano eruptions have a limited effect of 3 4 years as well In fact if Douglass and Clader by explicitly taking off the ENSO and the volcano signals find solar induced oscillations of 0 1K and we with another method find the same thing we have to conclude that everything works sufficiently well In any case the important thing is the value of the sensitivity at 11 year solar cycle and this is given by Z11y 0 11 0 02 K W m 2 Fourth critique sensitivity at slower trends and spurious trends Dr Benestad states From regression analysis cited by the authors Douglass and Clader 2002 White et al 1997 it seems possible that the sensitivity of global surface temperature to variations of total solar irradiance might be about 0 1K Wm 2 S W do not present any convincing result that would point to noticeably higher sensitivities to long term variations Their higher values are based on unrealistic assumptions Perhaps Dr Benestad would be more convinced after a more carefully reading of our paper About the transfer sensitivity to 22years Z22y 0 17 0 06 K W m 2 we have clearly explained in our paper that this is approximately 1 5 times larger than Z11y and this is in agreement with theoretical energy balance model estimates such as Wigley 1988 or Foukal et al 2004 The paper by Foukal et al 2004 is extremely clear on this larger sensitivity of climate to slower secular solar variations see their figure 1 In fact for slower solar variation the climate sensitivity should be stronger than for the 11year sensitivity because of the frequency dependency of the ocean thermal inertia and general out of equilibrium thermodynamics effects Moreover with an alternative method White et al 1997 have calculated something like 0 15 K W m 2 for the 22 year cycle Thus there are sufficient studies both theoretical and phenomenological confirming our results that for slower variations the climate sensitivity is stronger Dr Benestad finally states we have already discussed the connection between solar activity and this new analysis does not alter our previous conclusions that there is not much evidence pointing to the sun being responsible for the warming since the 1950s Well we have shown that the sun was responsible for 25 35 of the warming since the 1950s if we adopt the Lean s proxy reconstruction and PMOD and ACRIM satellite composites Dr Benestad s reasoning is based on the erroneous assumption that if there are no significant trends in some proxies for the solar activity since 1950s the sun is not contributing to the global warming This is wrong for two reasons First all TSI proxy reconstructions present a clear upward trend during the period 1900 2000 as a reader can see here http www grida no climate ipcc tar wg1 fig6 5 htm Second because the 1900 1950 TSI value was lower than the 1950 2000 TSI value this would induce by alone a solar induced climate warming of the atmosphere during 1950 2000 even if during the period 1950 2000 the sun was perfectly constant In fact as a reader can easily understand if I put a pot with cold water on fire the temperature of the water will slowly increase even if the temperature of the heater the fire is perfectly constant This is elementary out of equilibrium thermodynamics everybody knows Response Thanks for this interesting thought One question is then howto explain why the climate system takes so long to reach equilibrium

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    unprecendented rates or levels In the first place the many has been reduced to a handful of diehard outliers Most of these are shills for extractive energy interests on the payroll to keep injecting doubt into the body politic so business as usual practitioners can proceed unhindered by serious attempts to stop the pollution As to temperature rises have not been convincingly shown and I don t mean proven to be either at unprecendented rates or levels I ask with respect to when This is a strawman argument Nobody is claiming that AGHG warming will exceed the warming of the PETM for instance though it could provoke climate feedbacks which make it do that With respect to the last million years the levels of CO2 and the levels of warming are equal to and exceeding the highest iduring the MWP Global mean temperatures over land and ocean are the highest surface temperatures measured since before 1880 The observed rate of warming is also unprecedented with both the level and rate since 1979 being compelling evidence of rapid climate change see http www ncdc noaa gov img climate research 2005 ann global blended temp pg gif No natural forcing can be shown to cause the level or rate of global warming we have now A combination of human impacts can from carbon soot to CO2 to deforestation with anthropogenic CO2 the leading culprit From http www gaiehouston co uk climate htm The impact of the changing climate in the 20th Century IPCC Arctic air temperatures increased by about 5C in the 20th century ten times faster than the global mean surface temperature while Arctic sea surface temperatures rose by 1C over the past 20 years In the Northern Hemisphere spring and summer sea ice cover decreased by about 10 15 from the 1950s to the year 2000 sea ice extent in the Nordic seas has shrunk by over 30 over the last 130 years Arctic sea ice thickness declined by about 40 during late summer and early autumn in the last three decades of the 20th century Alaska s boreal forests have been expanding northward by some 100 kilometres for every one degree Celsius of temperature rise The major seal breeding grounds in the Bering Sea have seen fur seal pup numbers fall by half between the 1950s and the 1980s Precipitation over many mid to high latitude land areas in the Northern Hemisphere has become more and more intense Rainfall has generally declined in the topics and subtropics of both hemispheres when rain does fall it is frequently so heavy that it causes erosion and flooding In large parts of Eastern Europe European Russia Central Canada and California peak stream flows have advanced from spring to winter since more precipitation falls as rain rather than snow thus reaching rivers more rapidly than before In Africa s large catchment basins of Niger lake Chad and Senegal total available water has decreased by 40 Desertification has been exacerbated by lower average annual rainfall runoff and soil moisture especially in southern northern and western Africa Increased summer drying and the associated risk of drought have been observed in a few continental areas including Central Asia and the Sahel In the Alps some plant species have been migrating upwards by one to four meters per decade some plants previously found only on mountain tops have now disappeared Cold and cool water fish are losing suitable habitat warm water fish are expanding their ranges in both northern and southern hemispheres Changes in climatic variables have increased the frequency and intensity of pest and disease outbreaks as the related organisms shift their ranges poleward or to higher elevations Almost two thirds of the glaciers in the Himalayan and Tienshan mountains have retreated in the past decade Andean glaciers have also receded dramatically in the past several decades Vast expanses of the oceans have warmed over the past 50 years globally sea surface temperatures have risen in line with land temperatures The global mean sea level has risen by 10 20cm during the 20th century ten times faster than the rate for the previous three thousand years Seventy per cent of sandy shorelines have retreated over the past 100 years 2 30 per cent are stable while less than 10 per cent are advancing Seawater is seeping into freshwater aquifers and intruding into estuaries in low lying coastal areas around the world particularly on low lying islands end quote There s nothing theoretical about the observed effects and there s nothing theoretical about what most of it s caused by AGHG warming is certain enough to demand action And it s happening but all too slowly predominantly because of misleading skeptics such as PHE whoever that is 19 A Syme says 14 Sep 2006 at 8 32 PM In the 1980 s there was a book published called The Jupiter Effect The authers were trying to link earth changes to the position of the planets The one thing I remember from this book was their idea that during solor maxima the influx of charged particles from the sun was routed to the polar regions by the earths magnetic field This would actually raise the barometric pressure in the polar regions and push the jet stream farther south because of this winter would be colder in the mid latitudes 20 llewelly says 15 Sep 2006 at 1 15 AM Re A Syme In the 1980 s there was a book published called The Jupiter Effect I read it as a child I recall thinking it was akin to Worlds In Collision but marginally less kooky Unfortunately my memories of it are vague A quick google found this negative review 21 Martin Lewitt says 15 Sep 2006 at 6 31 AM Re Tim 18 Your list from the IPCC for the most part is evidence of global warming and not specific to an anthropogenic cause Re Wayne 2 A strong 11 year cyclic solar signal in the climate is not needed for the solar theory since there is evidence that for more than 60 years solar activity has been at one of its highest levels in the past 8000 years See the Solanki references already discussed at http www realclimate org index php p 180 We don t have accurate enough data on the increase in solar forcing since 1850 to determine how much of the recent warming was previously unrealized climate commitment from the continuing high levels of solar forcing vs how much was from increases in GHG forcing Unless we get models of solar behavior so accurate that when run them in reverse we can recover earlier levels of solar forcing with a high level of confidence we will never be able to confidently attribute the 20th century warming In addition attributing the recent warming would require model accuracies on the order 0 1W m 2 to apportion the on the order of 1W m 2 imbalance in the earth s energy budget between the various forcings globally and annually averaged We may not yet have enough accurate data to validate models to that level accuracy for another couple of decades some question whether even recent satellite data is accurate enough to validate models to that level of accuracy Current AR4 models were validated against the 20th century climate data despite having systematic positive biases in surface albedo that averaged nearly 2 a bias against solar forcing and while having climate sensitivities that varied by over a factor of two among the models This shows that current efforts at model validation are poorly constrained by the available data and have errors large than the phenomena we are trying to simulate Whether the current climate is warming and has unrealized climate commitment to further warming or even to cooling is all determined by net forcing imbalances smaller than 1 of the solar flux at the surface We have evidence that the climate is warmer and that there is commitment to further warming independent of the models but attributing past warming and projecting future warming is largely dependent on the models and they are not yet up to the task 22 Ferdinand Engelbeen says 15 Sep 2006 at 6 51 AM Re 19 and maybe of interest for Nereo in 12 because of the rain patterns With or without the Jupiter Effect there is observed evidence that the solar cycle s influence the jet stream position and rain patterns See Shindell for the NH See NASA for the USA And see what happens even on local scale here for Boston Or for the Mississippi delta And for Portugal There are many more examples Also longer term solar cycles are detected in nature 23 Jeffrey Davis says 15 Sep 2006 at 8 58 AM We have evidence that the climate is warmer and that there is commitment to further warming independent of the models but attributing past warming and projecting future warming is largely dependent on the models and they are not yet up to the task We have evidence that the train has lost its brakes and that the conductor is dead We can t be sure until the train either jumps the track or the engine runs out of steam So starting up our car and moving it from the crossing is a hasty thing to do 24 Phillip Shaw says 15 Sep 2006 at 11 57 AM Re 16 Mark I believe that you used the term negative feedback where you meant to use positive feedback These terms are borrowed from engineering and their connotations don t refer to whether they are beneficial or harmful but rather to whether they decrease the amplitude negative feedback or increase the amplitude positive feedback In talking about AGW negative feedback is positive beneficial and positive feedback is negative harmful 25 SecularAnimist says 15 Sep 2006 at 2 50 PM gavin wrote A new review paper by Foukal et al does a reasonable job summarising the mainstream opinion on the issue The main CNN web page today has a link to this Reuters article about that paper Study acquits sun of climate change September 15 2006 Reuters The sun s energy output has barely varied over the past 1 000 years raising chances that global warming has human rather than celestial causes a study showed on Wednesday Researchers from Germany Switzerland and the United States found that the sun s brightness varied by only 0 07 percent over 11 year sunspot cycles far too little to account for the rise in temperatures since the Industrial Revolution Our results imply that over the past century climate change due to human influences must far outweigh the effects of changes in the sun s brightness said Tom Wigley of the U S National Center for Atmospheric Research Most experts say emissions of greenhouse gases mainly from burning fossil fuels in power plants factories and cars are the main cause of a 0 6 Celsius 1 1 Fahrenheit rise in temperatures over the past century A dwindling group of scientists says that the dominant cause of warming is a natural variation in the climate system or a gradual rise in the sun s energy output The solar contribution to warming over the past 30 years is negligible the researchers wrote in the journal Nature of evidence about the sun from satellite observations since 1978 They also found little sign of solar warming or cooling when they checked telescope observations of sunspots against temperature records going back to the 17th century They then checked more ancient evidence of rare isotopes and temperatures trapped in sea sediments and Greenland and Antarctic ice and also found no dramatic shifts in solar energy output for at least the past millennium This basically rules out the sun as the cause of global warming Henk Spruit a co author of the report from the Max Planck Institute in Germany told Reuters Many scientists say greenhouse gases might push up world temperatures by perhaps another 3 Celsius by 2100 causing more droughts floods disease and rising global sea levels Spruit said a Little Ice Age around the 17th century when London s Thames River froze seemed limited mainly to western Europe and so was not a planet wide cooling that might have implied a dimmer sun And global Ice Ages like the last one which ended about 10 000 years ago seem linked to cyclical shifts in the earth s orbit around the sun rather than to changes in solar output Overall we can find no evidence for solar luminosity variations of sufficient amplitude to drive significant climate variations on centennial millennial or even million year timescales the report said Solar activity is now around a low on the 11 year cycle after a 2000 peak when bright spots called faculae emit more heat and outweigh the heat plugging effect of dark sunspots Both faculae and dark sunspots are most common at the peaks Still the report also said there could be other more subtle solar effects on the climate such as from cosmic rays or ultraviolet radiation It said they would be hard to detect 26 Willis Eschenbach says 15 Sep 2006 at 3 51 PM Re 18 there is a big problem with depending on the IPCC for your data For example you quote the IPCC as saying Arctic air temperatures increased by about 5C in the 20th century ten times faster than the global mean surface temperature while Arctic sea surface temperatures rose by 1C over the past 20 years However this is not the case at all The Jones dataset shows the Arctic air temperatures north of 65 N as warming by 1 C from 1900 to 2000 The GHCN dataset shows 1 1 C Arctic warming north of 65 N during the same period The Arctic Climate Impact Assessment ACIA report states Based on the analysis of the climate of the 20th century it is very probable that the Arctic has warmed over the past century although the warming has not been uniform Land stations north of 60 N indicate that the average surface temperature increased by approximately 0 09 C decade during the past century which is greater than the 0 06 C decade increase averaged over the Northern Hemisphere In other words the IPCC fact is wrong by a factor of five This is not surprising because the IPCC is a political body rather than a scientific body but it highlights the problem with depending on the IPCC for your facts w Response When is an IPCC fact not actually an IPCC fact When it doesn t appear in the IPCC report There are no such statements in TAR WG1 though there is a similar though ambiguous statement in WGII The actual wording appears to come from Mark Lynas s book High Tide quotation who sometimes reads this so maybe he can provide a clarification Rather than jumping to wild conclusions about the obvious political bias of the IPCC maybe five minutes with google would haved helped find the source of the quote and the possible cause of the mis interpretation Of course maybe it s more fun to jump to conclusions gavin 27 C W Magee says 15 Sep 2006 at 5 28 PM With regards to the cosmic ray experiment you have to remember that for particle physicists used to spending gigadollars on equipment 11 mil probably seems like a lot less money than it does for Earth scientists used to grants in the tens of kilodollar range 28 Mark Bahner says 15 Sep 2006 at 8 03 PM Submitted without comment SCIENTISTS PREDICT SOLAR DOWNTURN GLOBAL COOLING New Scientist magazine 16 September 2006 RUSSIAN ACADEMY OF SCIENCE REPORT WARNS OF GLOBAL COOLING IN 6 9 YEARS MosNews 25 August 2006 29 Jeff Weffer says 15 Sep 2006 at 8 07 PM The Sun clearly has cycles There is VERY clearly an 11 year cycle and there is VERY clearly a longer term cycle greater than 325 years we don t know how long it is because we are still in it http solarscience msfc nasa gov images ssn yearly jpg So the Sun a powerful complex body has at least two clear cycles We don t know how many cycles the Sun really has or how much variance there may be in those cycles And Sunspots are just an indication of what is happening in the Sun The Sunspots themselves are not the culprit they are just an indicator We also know there is a clear 115 000 year cycle of ice ages followed by inter glacials Why the rush to judgement to discount solar cycles when they are clearly there 30 A Syme says 15 Sep 2006 at 8 36 PM Another item that needs to be looked at in the earth sun connection is the influence of the earths magnetic field Far from being static always in a state of flux the changes are well documented in rock formations Has anyone looked at the history of the magnetic field in relation to past climate changes Response yes There isn t any gavin 31 Grant says 15 Sep 2006 at 11 10 PM Re 29 The 11 year solar cycle is indeed quite clear But I don t know of any evidence for other cycles in solar output As has been discussed here often it s not possible to conclude cyclic behavior from a time series which is shorter than the supposed cycle The cycle of ice ages is believed not to be due to changes in solar output but in the amount of solar energy intercepted by earth and its geographic distribution due to cyclic changes in the earth s orbit The fact that ice ages correlate with earth s orbital variations argues very strongly that it s the orbit and not the sun that has been causing climate variations driving the ice ages for the last million years or so What s your evidence for solar cycles besides the 11 year cycle 32 Hank Roberts says 16 Sep 2006 at 12 24 AM We don t know how variable the Sun is over the longer term One of the first impressions from melted rocks photographed on an Apollo visit suggest a huge flare event that s used as the premise for this story http homepage ntlworld com adam milner books inconstant moon htm Brief flare events in fact have been remarkable http www otago ac nz news news 2004 16 03 04 press release html Study of the melted Moon rock samples that made the premise for Niven s science fiction story seems to have kept that size flare in the realm of fantasy though http www sciencemag org cgi content abstract 172 3983 556 33 Willis Eschenbach says 16 Sep 2006 at 1 30 AM Re 18 Gavin thank you for your response I m not sure what you mean when you say that the 5 C century is not from the IPCC The TAR says The land stations show that warming in the Arctic as indicated by daily maximum and minimum temperatures has been as great as in any other part of the world Although not geographically uniform the magnitude of the warming is about 5 C per century with areas of cooling in eastern Canada the north Atlantic and Greenland Koerner and Lundgaard 1996 Borzenkova 1999a b Jones et al 1999 Serreze et al 2000 Now a statement like the magnitude of the warming is about 5 C per century seems pretty clear to me but in case it was ambiguous or meant only warming in a certain area of the Arctic I took a look at the Arctic temperature records from 65 N to 90 N by 30 segments I calculated the trends from either 1900 2000 or as much of that period as there were records The greatest warming was in the area above Alaska and western Canada from 180 W to 120 W This area was affected by about a 1 temperature rise from the PDO in 1976 78 This warming far from being 5 century was a maximum of 1 3 century and an average of 1 2 century including the PDO shift Outside of this 180 W 150 W area the greatest warming was 0 5 and the average warming was 0 because of the above noted cooling in Canada etc mentioned above that is to say no warming at all To summarize 1 4 of the Arctic was affected by the PDO shift and warmed by 1 2 The other 3 4 of the Arctic did not warm at all Indeed the references quoted by the IPCC such as Figure 3 of Serreze et al 2000 show that the Arctic as a whole is no warmer now than it was in 1930 To paraphrase your rather abrupt response to me rather than jumping to wild conclusions about the lack of political bias of the IPCC maybe five minutes with the actual data would haved helped you to verify that the IPCC claim of 5 century warming anywhere in the Arctic was simply not possible Of course maybe it s more fun to jump to conclusions w Response Try figure 1 in the Serreze et al paper There are large areas of the Arctic with trends 0 5 decade i e 5 century These are recent trends not the change over the century though which is why the WGII statement was ambiguous The paraphrasing that you objected to originally was incorrect but that paraphrasing did not come from IPCC Had I reviewed the text which I didn t I would have suggested making their statement more explicit I ll leave it to the readers to decide who s the long jumper here gavin 34 William Astley says 16 Sep 2006 at 3 07 AM Re 31 The fact that ice ages correlate with the earth s orbital variations argues very strongly that it s orbit and not the sun that has been causing climate variations driving the ice ages for the last million years or so The above statement is incorrect for the following reasons If the 10kyr so called warm period Holocene current followed by the 90kyr glacial period Wisconsin last has only due to orbital changes the earth would now be starting the next glacial period as the planet is currently farthest from the sun during the summer solstice June 21 and closest to the sun during the winter solstice December 21 which is exactly opposite to the orbital position 11kyrs ago at the beginning of the warm period Cold summers are a necessary condition to begin the glacial period and warm summers are required to end the glacial cycle The Greenland ice sheet record shows sharp periodic drops in temperature which cannot be explained by slow orbital changes For example the Greenland Ice Cores show 10C to 30C periodic drops in temperature on the ice sheet The Rapid Climatic Change Events RCCEs called Rickys occur in less than a decade last roughly 100yrs at which time the temperature on the ice sheet recovers to a level lower than the temperature at the beginning of the RCCE cycle During the RCCEs there is an 800 times increase in dust in the ice sheet record as compared to current conditions Some believe the massive increase in atmospheric dust and the very very windy conditions during the periodic RCCEs bring iron to the vast areas of the ocean that are currently almost lifeless due to low iron Iron is an essential metal in chlorophyll The extra iron some believe cause a significant increase in phytoplankton production The increased phytoplankton production during the RCCEs reduces the CO2 level in the atmosphere which along with the increase in the ice sheet further cools the planet Atmospheric CO2 is around 300 ppm in the warm period It drops in stages to 180 ppm at the end of the glacial period at which time 1 3 of the earth s land mass and vast areas of the high latitude oceans are covered with ice The question as to what causes the RCCEs has not been answered Solar variance is most certainly on the short list of suspects The following is an excerpt from M Christl et al s 2004 paper in the Journal of Atmospheric and Solar Terrestrial Physics which explains how the sun could affect the earth s temperature A leading candidate to explain the link between relatively feeble solar fluctuation and climate is the effect of solar magnetic modulated glactic cosmic rays GCR on cloud formation Editors of science 2002 their contribution to the global radiation climate forcing is estimated to be about 28 W m 2 Hartman 1993 This is one order of magnitude larger than the radiative forcing caused by the anthropogenic greenhouse gases IPCC 2001 The infrequent and periodic solar event that would cause a RCCE is something that increases cloud formation in my opinion both directly Extended period of massive solar flares Solar flare composition may differ from the current flares and indirectly Change in the number of sunspots per cycle such as the Maunder minimum Astronomers have observed both events in other stars that are a similar age size and composition as our sun The physics as to why these solar events are occurring and what controls their periodicity is not known at this time Response ice ages generally refers to the long term cycles 20 000 to 100 000 years which are highly correlated to orbital variations The shorter term millenial variations sometimes called Dansgaard Oeschger events or interstadials are a very separate phenomenon for which the triggers are not yet fully understood although the ocean overturning circulation is strongly implicated There is no clear evidence that solar forcings are responsible The quoted statement above was correct and your characterisation of the Holocene is not High northern latitudes have indeed cooled from their peak around 10kyr ago and there are hints that the tropics have warmed exactly in line with what is expected from orbital forcing Kim et al 2004 gavin 35 Harry N says 16 Sep 2006 at 4 04 AM Speaking of media coverage of the Nature study we have this piece over at National Geographic News The link is to page two where the reporter quotes Solanki as saying These authors have looked at the simplest mechanism and they find that this mechanism does not produce the same level of change that has been observed and that this could be suggesting that there are other mechanisms acting for the way that the sun influences climate Seems to be a fair amount of speculation there in the section entitled Sun Not Off the Hook for Warming including about galactic rays I thought there was no trend in them in recent decades I understand the need to consider possibilities but evidence is what counts in the end and perhaps it should be made more clear how much scientific support there is for any speculation put forth 36 Charlie T says 16 Sep 2006 at 4 33 AM Re 10 If new and updated TSI data are used then the trends they calculate vanish rasmus I am a bit confused which dataset has been updated If it is the ACRIM dataset then surely the climate sensitivity that they calculated from Lean et al 1995 irradiance since 1610 still stands at 1 5x to 3x larger than the model pedictions Or has the Lean et al 1995 reconstruction been revised 37 Ferdinand Engelbeen says 16 Sep 2006 at 9 43 AM Re 31 Have a look at more cycles here for biological activity and ice cover measured in sediments And in tree rings in Asia there are similar findings in Northern Europe And from ice cores page 13 Particularly exciting results from high resolution ice cores include the observation that many geochemical parameters show strong spectral power at frequencies close to or identical to those observed in the sun Worldwide coolings during the Holocene have a quasi periodicity of 2600 years in phase with previously defined 2500 year variations in d14C e g Denton and Karlen 1973 Stuiver and Braziunas 1989 1993 O Brien et al 1995 Also d18O in the GISP2 core is coherent with both the ice core 10Be time series and with the tree ring record of atmospheric 14C Stuiver et al 1995 Figure 11 Remarkably the series are coherent not only in phase but also in amplitude providing what is probably the best evidence to date for the elusive sunclimate relationship a subject of debate for more than a century For solar influences on the monsoon measured in a stalagmite The stalagmite revealed that cycles of 558 206 and 159 years on average are superimposed on a jumble of variations in monsoonal rains since the last ice age These climate periodicities resemble those in the record of varying carbon 14 in tree rings the authors note cycles widely attributed to variations in solar activity With a little Googling one can find many more Response With a little googling one can find many purported attributions of cycles to solar forcing but if one looks into most of them they are not coherent to each other nor to the 14C production funciton that is most reasonably tied to solar activity It s precisely because 99 of the these attributions don t actually cohere that the sub genre of solar forcing of climate has the reputation it has among many climate scientists Thus when working on this topic as I and others here have one has to be absolutely scrupilous not to uncritically accept claims that others have made The statement above for instance on the coherence of d18O and 10Be in ice cores is 99 a statement about snow accumulation changes not 10Be production which is modulated by solar Every time this kind of erroneous stuff gets quoted you make it harder for serious science to be done If as I presume you d like this to be looked at seriously take responsibility for your own descriptions of it and don t simply parrot stuff you find through google gavin 38 GH says 16 Sep 2006 at 2 24 PM Can anyone comment on Bard and Frank s Earth Planet Sci Lett 248 1 2006 From Science s Highlights of the recent literature service Bard and Frank provide a thorough critical review of both the problematic evidence for longer changes in solar irradiance and the possible climatic effects these changes could have induced The authors point out that many proposed connections for example between the records of cosmogenic nuclides such as 14C and 10Be and records of climate change are based on correlations some of which have large and perhaps unappreciated uncertainties and on imperfect and indirect records They conclude that there might still be a connection between solar changes and the Medieval Warm Period and Little Ice Age but that overall solar changes most of which remain unproven probably represent a second order influence on the behavior of Earth s recent climate 39 Willis Eschenbach says 16 Sep 2006 at 2 29 PM Gavin thank you kindly for your response in 33 You advise me to look at Figure 1 in Serreze which shows that there are a few small places a total of about 17 of the area in the Arctic that have warmed rapidly during the thirty year period from 1966 to 1995 However it is well known and supported by Serreze that the 1960 s were anomalously cold in the Arctic so that rise is neither surprising nor unnatural Now since only 17 of the area is warming at that rate it is highly misleading to state as the IPCC does that Although not geographically uniform the magnitude of the warming is about 5 C per century This is deception that reveals the IPCC bias only 17 of the area has been warming at that rate and not for the century but for only 30 years Because they were not discussing the warming since 1966 but the warming per century To describe this short term warming as 5 century is very misleading and reveals the political agenda of the IPCC It s like looking a 20 warming from 9AM to noon and describing it as 120 day It is mathematically correct since 20 in three hours works out to 120 in a day but a 120 rise in a day is as unlikely as a 5 Arctic rise in the last century w 40 Ferdinand Engelbeen says 16 Sep 2006 at 3 23 PM Re 37 comment Gavin I am aware of the accumulation problem in ice cores vs 10Be production As mostly I try to look at the evidence as described in the article itself In the case of the article I quoted the correlation of ice core 10Be is influenced both by solar activity and snow accumulation while d18O is directly connected to climate temperature ice sheet volume but that also correlates with 14C in tree rings over the same periods which is mainly connected to solar activity cycles I know of the controversy between solar scientists and climate model scientists IMHO climate scientists should listen a bit more carefully to what solar scientists say and include in the models a few items which are quite certain since the start of the satellite era A good example is the solar cloud connection over the last two cycles I mean the inverse correlation between TOA irradiation not GCR and cloud cover As far as I know no model does that predict or use that as parametrisation 41 Grant says 16 Sep 2006 at 6 26 PM Re solar cycles I worked for 10 years doing time series analysis for astrophysicists studying variable stars So I decided to look into the variability of the sun more closely A literature search identifies three classes of papers 1 Papers that conlude there is no confirmable influence of solar activity on climate 2 Papers that point out confirmable correlations of solar cycle activity with changes in the stratosphere but only hypothesize about possible effects on the troposphere or relating to SAT 3 Papers which Gavin quite correctly characterizes by but if one looks into most of them they are not coherent to each other nor to the 14C production funciton that is most reasonably tied to solar activity It s precisely because 99 of the these attributions don t actually cohere that the sub genre of solar forcing of climate has the reputation it has among many climate scientists Frankly I think he was a little kind I saw papers that tout complex mathematical models but give no clue as to what the model is papers that claim strong correlation when no numerical estimate of significance is given nor are the statistical tests described graphs illustrating strong correlation which look rather obviously like the correlation is false and I don t say such things lightly I do this professionally papers with no references always a warning sign Overall the quality of the research published that falls into class 3 is there s no polite way to say this abysmal The best research I ve found so far was already noted in 38 They conclude that there might still be a connection between solar changes and the Medieval Warm Period and Little Ice Age but that overall solar changes most of which remain unproven probably represent a second order influence on the behavior of Earth s recent climate I remain highly skeptical of attribution of global warming to solar variability 42 Tim Jones says 16 Sep 2006 at 6 03 PM Willis Eschenbach wrote Re 18 there is a big problem with depending on the IPCC for your data For example you quote the IPCC as saying Arctic air temperatures increased by about 5C in the

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    due to contaminations of the land temperature record They call it an anomalous behaviour ignoring that it corresponds fully to what is physically expected Maybe it would help them to have a look at the IPCC report The many problems in their analysis have been discussed above and before 11 SecularAnimist says 11 Oct 2006 at 1 21 PM FYI Water for Millions at Risk as Glaciers Melt away by David Adam October 11 2006 The Guardian UK Excerpt The world s glaciers and ice caps are now in terminal decline because of global warming scientists have discovered A survey has revealed that the rate of melting across the world has sharply accelerated in recent years placing even previously stable glaciers in jeopardy The loss of glaciers in South America and Asia will threaten the water supplies of millions of people within a few decades the experts warn Georg Kaser a glaciologist at the University of Innsbruck Austria who led the research said The glaciers are going to melt and melt until they are all gone There are not any glaciers getting bigger any more Dr Kaser said that 99 99 of all glaciers were now shrinking Increased winter snowfall meant that a few most notably in New Zealand and Norway got bigger during the 1990s he said but a succession of very warm summers since then had reversed the trend His team combined different sets of measurements which used stakes and holes drilled into the ice to record the change in mass of more than 300 glaciers since the 1940s They extrapolated these results to cover thousands of smaller and remote glaciers not directly surveyed The results revealed that the world s glaciers and ice caps defined as all land based ice except the mighty Greenland and West Antarctic ice sheets began to shrink far more quickly in 2001 On average the world s glaciers and ice caps lost enough water between 1961 and 1990 to raise global sea levels by 0 35 0 4 mm each year For 2001 2004 the figure rose to 0 8 1mm each year Writing in the journal Geophysical Research Letters the scientists say Late 20th century glacier wastage is essentially a response to post 1970 global warming Dr Kaser said There is very very strong evidence that this is down to human caused changes in the atmosphere 12 Steve Sadlov says 11 Oct 2006 at 1 21 PM Some problems 1 They appear to have looked at things globally perhaps looking at regions responses would have been better 2 Assuming a direct transfer function between irradiance and temperature instead of second order effects of irradiance and temperature or even instead of other non irradiance measures related to impinging full band EM energy of solar or other extreterrestrial origin they may have made a bit too much of a leap 3 They appear not to postulate specifically enough regading mechanisms for example postulating a specific role for a specific energy bands impingement accentuating or impairing cumuloform cloud formation in the tropics 13 PeakEngineer says 11 Oct 2006 at 1 43 PM It seems unconscionable to me for SW to exclude all contributing factors and claim their results have any merit In most professional circles I m familiar with particularly in aerospace engineering omitting such obvious factors could bring serious professional consequences In this field with lives even more at stake than with those flying an engineered aircraft it is irresponsible to present such an erroneous result as they did 14 John L McCormick says 11 Oct 2006 at 2 47 PM RE 11 SecularAnimist a good and timely link to the important work of Dr Kaser and colleagues at the Tropical Glacier Group Innsbruck University A link to their publications is http tinyurl com f9ouh and a further link to that report is http tinyurl com lzgrd Their work builds upon the expanding volume of observed and measured data including the vital work of Dr Lonnie Thompson at Ohio State Univ confirming what reasonable people agree a warmer world melts glaciers and perhaps more rapidly than earlier imagined RealClimate posted a very informative thread on tropical glacier retreat and is worth a revisit http tinyurl com n2lpo I believe India Pakistan Kashmir Nepal China will feel the full effect of lost glacier melt runoff that feeds major rivers in their part of the world and provide irrigation and drinking water for tens of millions of people Sometimes I wonder if we are all in a collective dream about glacial melt back because it does not appear to be of any real interest to the CIA National Security Council or the Council on Foreign Relations Why am I concerned and they appear to be ignorant of the consequences of losing Himalayan glaciers Maybe it is simply that I accept AGW and for them to poke into the glacier melt back studies is an admittal there is a looming problem that will dwarf WMD and democratization of the Middle East Mass migration of hungry and desparate farmers and villages along the norhtern coast of the Indian Ocean is a frightening prospect Guess the large brained national security types have their hands full trying to secure our future oil supply Silly me 15 Charlie T says 11 Oct 2006 at 3 27 PM I am surprised that the left hand side of your modified graph is annotated with Trend in reconstr but not in T In the period you ve shown if one looks at the low frequency component of the Moberg reconstruction there is a clear max at around 1630 and a minimum at around 1675 Smoothing the full Moberg reconstruction yields maxima and minima that are slightly further apart 1620 and 1690 The trend over this period is only about a degree which looks to be about a third the size of S W but they are trends none the less Have you cut out the middle of Fig2 so as to stop readers developing unsavoury thoughts of a solar nature 16 chris says 11 Oct 2006 at 3 51 PM speaking of peer review I noticed an interesting sounding review entitled The Global warming Debate A Review of the State of the Science in PURE AND APPLIED GEOPHYSICS 162 1557 1586 2005 It turned out to be interesting but for all the wrong reasons I m a scientist but not a climate scientist molecular biology actually However it is blatantly obvious that this so called review by ML Khandekar TS Murty and P Chittibabu is a disgraceful and I would have thought embarrassing piece of propaganda full of downright falsehoods about the state of science A number of questions come to mind about this Clearly the editors of this journal which I assumed was respectable but I now wonder are aware that they have allowed a piece of misrepresentational garbage to appear in their journal So are they part of and party to this process of misrepresentation In the normal course of events the scientific process would pertain People publishing blatant rubbish would lose their scientific credibility Authors might think twice before submitting their work to this journal The paper would be ignored and sink into oblivion But in normal fields of scientific endeavour like molecular biology for instance this sort of rubbish just doesn t happen I thought about doing several things none of which I did in the end Writing to the editors to express my distaste along with a synopsis of the errors and misrepresentations that are obvious even to a molecular biologist I considered discussing having the journal subscription cancelled by our university Is there a useful way of adressing this problem Or do we just accept that the normal scientific publication process has been infiltrated at several levels presumably up to the editorial level in this case and just allow time to deal with the still very small misrepresentations and propaganda dressed as science that surprisingly for me has been allowed to ooze into the mainstream scientific literature Or maybe Pure and Applied Geophysics isn t mainstream scientific literature 17 porsha says 11 Oct 2006 at 5 15 PM this is vey know in my country climate is not very variable 18 Steve Reynolds says 11 Oct 2006 at 5 46 PM Mass migration of hungry and desparate farmers and villages along the norhtern coast of the Indian Ocean is a frightening prospect If changing to energy intensive agriculture allows more food to be produced by just 2 of Indian farmers on half of the previous land that should be no more frightening than when the other 98 of US and Canadian farmers migrated to cities in the late 19th and early 20th centuries 19 Barbara J Gill says 11 Oct 2006 at 6 37 PM Watching with great interest Will be back Barbara 20 Hank Roberts says 11 Oct 2006 at 7 21 PM The Kandehar paper was discussed for a while last year starting here http johnquiggin com index php archives 2005 07 17 disinterested sceptics comment 29646 21 Ferdinand Engelbeen says 11 Oct 2006 at 7 24 PM Rasmus I have purchased again AGU must get rich from all those single contributions the article And have some problems with your comment They used the difference between 17th and 18th 19th century as that are the largest differences Of course if one uses a smaller difference as like between the 18th and 19th century about 3 1 4 1 that increases the error margins the error margin is up to 50 for the 18 19th century difference 5 20 for the others But that doesn t show that the method itself is wrong or gives unacceptable answers Thus your Fig 1 end only shows that the error in the scaling factor blows up with smaller differences which they of course didn t use to calculate their factors The transfer functions range from 0 20 to 0 57 This is for different solar reconstructions all by Lean ea As the different solar reconstructions only differ in amplitude not in shape with the same temperature reconstruction the endresult is nearly the same That doesn t show any inconsistency in the method used only that smaller differences in solar reconstruction need larger factors to explain the reconstructed temperature As already said land use changes probably had and have a limited effect on global temperatures as good as volcanoes less than 0 1 K Thus the remaining pre industrial variability is mostly solar and internal variability According to several Antarctic ice cores there was a 10 ppmv drop in CO2 between the MWP and LIA this points to a 1 K drop in global temperature which is more in line with the higher variable reconstructions One shouldn t highlight short discrepancies in the trends what is of interest is the overall trend The 1900 2000 NH temperature trend is 0 8 K GISS NH 5 year smoothed An extra 0 1 K is added after the year 2000 Further The Moberg reconstruction ends in 1950 thus the comparison for the 1900 2000 period probably uses part of the Moberg reconstruction and part of the instrumental record for the period 1950 2000 There is a known problem with tree ring based reconstructions for the period after 1950 the divergence problem which still is not resolved Moberg s reconstruction also uses other proxies but these are not extended after 1950 This makes any comparison after 1950 or 1980 for solely tree ring based proxies rather problematic About the attribution of climate responses to different forcings in current GCM s as used in Fig 1 of this page volcanic is overestimated The Pinatubo of which strength there were only 9 in the past 600 years see Fig 6 from Briffa had an influence of 0 6 K in its peak year much less in the next years The decadal average thus is less than 0 1 K In the beginning of the century there were 2 consecutive eruptions with the same strength 10 years apart Over the rest of the century much less Thus the smoothed variation over the century should be less than what is shown anyway without positive value I have never heard of an inverse volcanic effect sulfate aerosols are largely overestimated Because of their very short lifetime a few days vs volcanoes a few years for identical physico chemical reactions their primary effect is less than of volcanoes despite the higher emission rates secondary and tertiary effects even are far more uncertain For a comprehensive overview of all my doubts on aerosol influence see my comment on RC here But if the negative influence of aerosols and volcanic is overestimated the modeled trend would be way too high That means that the positive response to GHGs must be lower than currently implemented in the models the direct effect without feedbacks of anthropogenic GHG forcing is currently 0 3 K Thus that 50 of the past century warming may be attributable to solar forcing comes into sight even in current models with more realistic estimates Last but not least do you know of trends from any climate model which covers the full 400 year as what S W did compared to the Moberg reconstruction and has that a better performance I have found Fig 1 in Cubash ea and a strange graph as Fig 1 in Widmann and Tett with natural influences only runs giving higher 1900 2000 temperatures than runs with natural anthro Compare these to the performance of the S W trends 22 Hank Roberts says 11 Oct 2006 at 7 29 PM 16 The Kandehar paper was discussed for a while last year starting here http johnquiggin com index php archives 2005 07 17 disinterested sceptics comment 29646 It s been cited only once per Google Scholar in an article on algae growth on buildings Oblivion enough 23 Nicola Scafetta PhD says 11 Oct 2006 at 9 00 PM I am the author of the paper under accuse I try to reply to Dr Rasmus when I finished writing this comment I saw that 21 replied already to Dr Rasmus very well but I add my comments any way BTW papers may be obtained for free by writing an email to the authors for example 1 The greatest flaw Dr Rasmus uses the differences between averages during the 18th and 19th centuries while I started from the 17th century and he found unrealistic results So Why didn t I do the same Rasmus calculations Well Rasmus adds these comments In my physics undergraduate course we learned that one should stay away from analyses based on the difference between two large but almost equal numbers especially when their accuracy is not exceptional and hence neglect factors natural forcings such as landscape changes that the North America and Europe underwent large scale de forestation and It is however possible to select two intervals over which the average total solar irradiance is the same but not so for the temperature When the difference in the denominator of their equation is small the changes in the total solar irradiance are small then the model blows up Well I think Rasmus has given also answer It is unsafe to do the calculations comparing the 18th and 19th centuries because the errors will be much larger due to the fact that the averages are very close and because the 19th century would be already partially effected by some anthropogenic factors due to the beginning of the industrialization and some deforestation that is an anthropogenic component too So I used an algorithm that stresses the values during the previous 17th and 18th centuries when anthropogenic contamination is practically zero 2 A charm cutting a picture in two By cutting my picture in two Dr Rasmus gives the impression that his calculations are fine The truth is that with my calculation a reader can see an evident correspondence that is a good fit between the temperature and the solar signal during the pre industrial before 1800 1900 era that suggests my results are reasonable By using Rasmus numbers the correspondence would be visibly lost because he gets a double value for the sensitivity that would imply double amplitudes of the reconstructed solar induced temperature signal that would not fit the data for any of the 4 centuries any more 3 Ambiguities on numbers Dr Rasmus writes the results gave a wide range of different values for the transfer functions from 0 20 to 0 57 Well Dr Rasmus did not realize that I am using three different solar records He should read more carefully my paper Look at figure 1 Dr Rasmus writes But the figure in the SW paper would suggest at the most 40 Well a carefully look would have the solar signal value of 0 45K 1900 and ending at 0 0K 2000 so the difference would be 0 45K The temperature goes from 0 40K 1900 to 0 50K 2000 look at the average value between 1950 2000 so the difference is 0 9K Well the value is 50 correct 4 Galileo and the inquisition Dr Rasmus writes Looking at the SW curves in more detail their Fig 2 one of the most pronounced changes in their solar based temperature predictions is a cooling at the beginning of the record before 1650 but a corresponding drop is not seen in the temperature curve before 1650 Well let us look at the history Galileo just started to observe the sun spot since 1611 The sun spot measurements from 1611 and 1650 are probably quite poor so the TSI reconstructions during that time are poor because poor are the data And then there were the religious wars in Europe and the inquisition I guess that perhaps the 17th centuries guys involved in these matters were to busy to think to fix the measurements to avoid the comments by Dr Rasmus 5 A good point Dr Rasmus writes The proper way to address this question I think would be to identify all the physical relationships Well I agree but today we do not know all the physical relationships that is why I wrote To circumvent the lack of knowledge in climate physics we adopt an alternative approach etc etc I hope this is helpful Response Thanks for your repsonse Dr Nicola Scafetta However I m still not convinced as the temperature is not only affected by greenhouse gases and solar activity take the ice ages for example I think your choice of method is not robust and is likely to provide wrong answers and one can illustrate that by applying the same method to the difference between the 19th and 18th centuries for which you say factors other than solar may play a role just my point You ask me a question a carefully look would have the solar signal value of 0 45K 1900 and ending at 0 0K 2000 so the difference would be 0 45K The temperature goes from 0 40K 1900 to 0 50K 2000 look at the average value between 1950 2000 so the difference is 0 9K Well the value is 50 correct I may misread the figure but the solar signal seems to be lower than 0 0K at year 2000 An the temperature seems to be greater than 0 50K but my reading may have been disturbed by the fact that not many years later the temperature exceeds 0 6K rasmus 24 SqueakyRat says 12 Oct 2006 at 12 13 AM I ve been lurking here for years gathering such understanding as I m capable of which is only partial I just wanted to say how grateful I am and admiring of your efforts integrity and dedication Your science is beautiful and crucial We need you guys 25 David Graves says 12 Oct 2006 at 2 04 AM Perhaps Steve Reynolds 18 missed the stories in the NY Times regarding groundwater depletion and problems with surface water supplies in India Or he has never heard of the fate of the agricultural production dpendent on the Ogalala Aquifer 26 Ferdinand Engelbeen says 12 Oct 2006 at 3 10 AM The URL for the reconstruction of volcanic influences from Briffa ea can be found at http www cru uea ac uk cru posters 2000 03 TO mendoza pdf Fig 6 It looks like that current models simply have adopted the Briffa reconstruction compare Fig 6 of Briffa with Fig 1 on this page without looking at the physical evidence 27 Urs Neu says 12 Oct 2006 at 5 06 AM Re 23 Dear Nicola Sorry but your explanations did not help very much yet There remain several questions e g You state that Sun spot observations before 1650 are poor However this is half of the data for the 17th century value This would mean your value for the 17th century is poor and in fact you shouldn t use it You state that the measurements in the 19th century are already anthropogenically influenced This means that your value in the 19th century has an anthropogenic influence and is not only solar induced According to your Zs values the error bars and the TSI values the temperature should have increased from the 18th to the 19th century between 0 03 and at most 0 06 In fact the increase was 0 08 which is between 30 and 160 more You seem to explain this by possible anthropogenic influence However if the anthropogenic influence in the 19th century possibly is more than 50 how can you use the value of the 19th century in a calculation which assumes nearly 100 solar influence Thus if the data is poor before 1650 and is possibly anthropogenically influenced after 1850 it might be more appropriate to compare 1650 1750 and 1750 1850 A rough estimate from the graphs shows that you would get Zs values between about 0 10 or even below and about 0 25 for the three TSI reconstructions which is about half of what you get And a last question You compare different TSI reconstructions Why don t you also compare different temperature reconstructions Response I think that the sunspot data for the 18th and 19th is questionable as well because there are something strange happening to solar cycle length rasmus 28 Nicola Scafetta PhD says 12 Oct 2006 at 11 54 AM Rasmus I cannot convince everybody You write that by applying the same method to the difference between the 19th and 18th centuries for which you say factors other than solar may play a role just my point Yes Rasmus by doing the calculations as you want to do them the result would be not robust That is why I chose to do the calculations in a different way You are criticizing your own calculations and your own methodology not mine About the numbers in the paper I wrote approximately 50 the error is about 15 20 of that value So it is fine A short reply to 27 1 I use the reconstructions that are available All reconstructions might have problems 2 I did not use the 19th century at 100 value but an agorithm that stesses the 17th and 18th century values and then I checked that the things look OK 3 In the paper I used Moberg data because these data are the latest one And because in GRL we have a limited number of pages Response Rasmus point is I think more general In any period there will likely be more than one thing going on This is as true for the 17th Century as for the 19th Century These other things principally volcanoes but also land use etc are presumably uncorrelated with solar forcing over the long term but in the absence of enough centennial cycles in the observational record one can t assume that you can average over them by taking enough examples In the late 17th Century for instance our work has suggested about a 50 50 split between volcanic and solar effects compared to the late 18th Century which enhances the global cooling Other studies have come up with other splits including some which find a dominant role for volcanic forcing It s not easy to distinguish between the two given the uncertainties in the forcing data but it might preclude one from simply assuming that it was all solar gavin Response I think we are not quite on the same frequency to give you a clue I m not critising myself but only demonstrating that you method is not reliable and I hope that Gavin s explanation helps On a more specific issue even counting in errorbars the usual way to do this is this to center the range around the best estimate so you should have written 40 error How did you estimate the error is it one standard deviation or the 2 5 97 5 quantiles by giving a range 15 20 gives me the impression of being a bit handwavy but 20 of 40 is 8 right And that upper limit is not the most likly estimate But the figure is reproduced above and the readers can make up their own minds rasmus 29 lars says 12 Oct 2006 at 12 25 PM Study Links Extinction Cycles to Changes in Earth s Orbit and Tilt By JOHN NOBLE WILFORD If rodents in Spain are any guide periodic changes in Earth s orbit may account for the apparent regularity with which new species of mammals emerge and then go extinct scientists are reporting today It so happens the paleontologists say that variations in the course Earth travels around the Sun and in the tilt of its axis are associated with episodes of global cooling Their new research on the fossil record shows that the cyclical pattern of these phenomena corresponds to species turnover in rodents and probably other mammal groups as well In a report appearing today in the journal Nature Dutch and Spanish scientists led by Jan A van Dam of Utrecht University in the Netherlands say the astronomical hypothesis for species turnover provides a crucial missing piece in the puzzle of mammal species and genus level evolution In addition the researchers write the hypothesis offers a plausible explanation for the characteristic duration of more or less 2 5 million years of the mean species life span in mammals Dr van Dam and his colleagues studied the fossil record of rats mice and other rodents over the last 22 million years in central Spain The fossils are numerous and show a largely uninterrupted record of the rise and fall of individual species Other scientists say rodents thanks to their large numbers are commonly used in studies of such evolutionary transitions As the scientists pored over some 80 000 isolated molars the most distinct markers of different species the patterns of turnovers emerged They seemed often to occur in clusters which seemed unrelated to biology And they occurred in cycles of about 2 5 million and 1 million years continues in link http www nytimes com 2006 10 12 science earth 12extinct html ei 5065 en 83d5e73f9f09c803 ex 1161316800 partner MYWAY pagewanted print 30 cbone says 12 Oct 2006 at 2 17 PM It seems unconscionable to me for SW to exclude all contributing factors and claim their results have any merit In most professional circles I m familiar with particularly in aerospace engineering omitting such obvious factors could bring serious professional consequences In this field with lives even more at stake than with those flying an engineered aircraft it is irresponsible to present such an erroneous result as they did I think they learned it from watching so called climate scientists do the same thing when they focus all the blame on CO2 Response Why not try reading what we so called climate scientists actually say Sorry to be snippy but it can get a little tiresome to always be dealing with strawmen arguments gavin 31 muller charles says 12 Oct 2006 at 2 34 PM In the 20 or so AOGCM models used by IPCC for simulation of XXth and projection on XXIth centuries do you know how many use some varying value for solar radiative forcing and how many consider it as constant or ignore it as insignificant Response In the 19 models studied in Santer et al 2005 Table 1 11 models have historical variations in solar irradiance 7 don t and one was uncertain I m sure there is a better description of the specific forcings for each model somewhere but I don t know where anyone gavin 32 Eli Rabett says 12 Oct 2006 at 9 50 PM It seems to me if you only can get the given result by using a particular pair of 100 year intervals you are in deep doo doo For example if you start using 1600 to 1700 how does the result change if you use 1610 1710 1620 1720 etc As Gavin points out what is being done is to pick one particular set of differences from a set of measurements which are both noisy and not particularly well known Also wrt 18 the Enclosure Acts did not lead to a life of milk and honey for the displaced farmers and in the US for example the life of the Okies displaced from their farms by an ecological disaster was not celebrated for the ease and luxury they found in the cities 33 Blair Dowden says 12 Oct 2006 at 10 06 PM Re 29 We are a bit off topic here but I saw this article and would like to know which 2 5 million and 1 million orbital cycles they are talking about The eccentricity and obliquity axial tilt cycles they mention have periods of about 100 000 and 22 000 years respectively 34 Ike Solem says 12 Oct 2006 at 10 20 PM Regarding 16 and 22 It s always interesting to read a paper like the one you reference and then take a look at who the authors are and what their background is Here s a quote from the paper During the long geological history of the earth there was no correlation between global temperature and atmospheric CO2 levels Earth has been warming and cooling at highly irregular intervals and the amplitudes of temperature change were also irregular The warming of about 0 3 C in recent years has prompted suggestions about anthropogenic influence on the earthâ s climate due to increasing human activity worldwide However a close examination of the earthâ s temperature change suggests that the recent warming may be primarily due to urbanization and land use change impact and not due to increased levels of CO2 and other greenhouse gases This is a nonsensical view Khandehar has previous record on this issue for example at http gmopundit blogspot com 2006 09 indias successful agricultural html INDIA S ECONOMIC PROGRESS IN A CHANGING CLIMATE BENEFITS OF GLOBAL WARMING As a weather climate scientist what impressed me was the fact that India s strong economic progress has come about in an increasingly warmer world of the last forty years or so completely defying the projections of deleterious impact of Global Warming by IPCC Intergovernmental Panel for Climate Change a United Nations Group of Scientists and its supporters What about the other authors Tad Mundy has published a fair number of papers on tsunamis but nothing on climate last time I checked there was no relation between earthquakes and global warming This paper is his first on climate change generally reviews are written by leaders in their field P Chittibabu has published a few papers with Tad Mundy on tsunamis but that s it Of more interest is his employment with W F Baird and Associates a coastal engineering firm that also sells 3D imaging software a little research into this firm reveals that one of their main clients is likely the Canadian petroleum industry It s highly likely that restrictions on Canadian CO2 emissions would hurt their bottom line See http www esricanada com english solutions wfbaird asp and also http www esricanada com english nresources default asp petroleum for more As 22 points out this paper has been ignored by the climate science community That s not the problem the paper is available at http www friendsofscience org documents debate pdf Who is friends of science Here is the lead statement from their website The Kyoto Protocol is a political solution to a non existent problem without scientific justification This paper is used to promote that notion outside of climate science circles So why go to all this trouble In a nutshell Canadian tar sands in Alberta See http www ualberta ca parkland research perspectives GassyElephant06OpEd htm as they point out The tar sands are the single largest contributor to the growth of greenhouse gas emissions in Canada because it takes so much of Canada s diminishing supply of natural gas to make tar sands oil Greenhouse gas intensity in the tar sands is almost triple that of conventional oil As Jim Dinning Alberta s former treasurer and front runner to replace Ralph Klein as Alberta s premier recently quipped Injecting natural gas into the oil sands to produce oil is like turning gold into lead This really represents a serious abuse of the scientific process and the journal s editors should know better Is it appropriate to email the journal editor and ask what happened to the review process Well that s what I did so we ll see I imagine that these papers on solar influence on climate will also be widely posted on sites like friends of science 35 Robin Johnson says 13 Oct 2006 at 1 00 AM Re 33 The 100 000 and 22 000 year cycles coincide periodically Technically they should coincide every 1 100 000 years the least common multiple of 100 000 and 22 000 but the cycles are not exactly 100 000 and 22 000 and the time actually varies slightly depending on extraterrestial forces the other planets and internal Earth dynamics position of tectonic plates cryosphere core flows So the cycles theoretically are estimated to coincide at the times specified in the past those calcuations have inherent approximations due to limitations of underlying estimates required to make them Rodent extinctions in Spain correlating with this cycle is quite interesting but obviously hardly decisive evidence The crux of the hypothesis being that mammals would have a survival advantage over reptiles during periods of high seasonality and vice versa during periods of low seasonality primarily I suppose due to food mix changes temperatures and disease carrying insects 36 Lawrence McLean says 13 Oct 2006 at 1 07 AM A cousin of mine who is a Physicist and worked in solid state manufacturing is a total climate change denier he reasons that Carbon dioxide has insignificant interaction with infrared radiation as compared with H2O therefore the increased levels of Carbon dioxide cannot be influencing climate I believe that it is the case that Carbon dioxide has little interaction with the higher frequencies of infrared however I suspect that it is the lower frequencies of infrared that interact more with Carbon dioxide I have tried a Google on the issue and end up with too many hits that all seem to be about unrelated issues Can anyone please tell me the details for infrared Carbon dioxide interactions or direct me to a reference in which it is described I doubt that anything would change my cousins mind however I would like to give others to whom my cousin has preached the details in order to put them straight on the issue of whether or not Carbon dioxide is a greenhouse gas Cheers Lawrence Response You could try http www realclimate org index php archives 2005 04 water vapour feedback or

    Original URL path: http://www.realclimate.org/index.php/archives/2006/10/how-not-to-attribute-climate-change/ (2016-02-13)
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