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  • Global Dimming may have a brighter future « RealClimate
    Is AGD a possible contributor the LIA Doesn t the idea AGD conflict with the measure temperature rise during the first part of the 20th century After all if there were AGD at that time and the temperature rise of the first part of the 20th century is attributed as it normally is to natural attenuation then that would indicate a higher level of natural variation than previously thought Response Radiometer values are probably too imprecise and too few to make useful estimates pre 1950 it is apparently rather harder than one might suspect to measure downwards solar to the degree of precision required with no long term drift Anthro influence on climate is generally considered to start about 1850 ish so connecting it to the LIA is unlikely William 10 paul cole says 16 May 2005 at 5 36 PM Couldn t variations in dimming simply be due to volcanic activity and the amount of matter in the atmosphere caused by eruptions 11 John Finn says 17 May 2005 at 4 49 AM So the incoming solar is not just being reflected out to space at least not totally or even largely it may be partly it must be being redistributed either scattered and being absorbed somewhere above the surface or some other effect William Fair point some may be absorbed elsewhere But it s reasonable to assume that some is also reflected back into space The some no longer being reflected could easily account for the 1990s warming In fact what about this for a hypothesis Early 20th century reduced volcanic activity plus increased solar activity leads to increased global temperatures this is pretty much accepted anyway Mid 20th century increased aerosol effect reverses warming trend to produce slight cooling again more or less in line with current thinking Late 20th century cleaner technology results in reduced aerosol effect in atmosphere and a return to a warming trend I think I ve cracked it Response I think you re over interpreting it William 12 Michael Jankowski says 17 May 2005 at 8 46 AM Anthro influence on climate is generally considered to start about 1850 ish so connecting it to the LIA is unlikely I m well aware of this but aren t people usually thinking in the context of GHGs not particulates As for the pre 1950 dimming values air pollution was extremely bad at times Waves of deadly smog and black fog have been recorded Couldn t these have been significant enough to affect global temps and if so then wouldn t they have masked some of the natural warming that we witnessed in the first part of the 20th century Response The true answer to both your questions is I don t know for sure But to some extent particulates aerosol scales with GHG emissions Which is why pre 1850 the values are likely to have been small globally however large they may have been locally But also yes its possible that they may well have had effects pre 1950s its just that the obs to verify this are hard to come by William 13 Ken says 18 May 2005 at 3 05 AM I ve had climateprediction running on my computer for a few months but I m not sure I m getting my money s worth Why hasn t global dimming brightening shown up in the models Is this sort of thing beyond the predictive capability of climate science Response It depends on the kind of experiment you are running If it is either a control or a CO2 doubling run you probably won t see it though that will depend on the cloud feedbacks in your configuration If you are doing a greenhouse gas sulphates run though I m not sure that is on offer then it s likely to be clearer You should probably ask on their message boards how you could diagnose this you need to find a diagnostic that sounds like incident solar radiation at ground gavin Response HadAM3 certainly includes sfc downwards SW as a diag 1 235 I think but whether its available from within the CP net framework is doubtful William 14 Jan Hollan says 18 May 2005 at 5 44 AM There is a simple reason why dimming or brightening have not so much to do with forcing Changes in daytime solar radiation reaching ground due to changes in atmospheric albedo by anthropogenic short lived tropospheric aerosols are large but they are compensated quite a lot by more thermal insulation working day and night for longwave infrared radiation clear sky insulates much worse Amount of compensation is difficult to compute This is the main idea which remained in my mind after reading all the papers and discussions about the problem the last time and forgetting them again I hope I don t oversimplify it Of course soot is warmed directly by sun so there is some redistribution too dimming is not the same as increased albedo 15 Michael Jankowski says 18 May 2005 at 8 35 AM Some pollution enhances the greenhouse effect some particulate pollution has slowed global warming and as stated in the link below some particulate pollution enhances both global warming and polar ice cap melting http www livescience com environment 050328 arctic soot html As if climate modeling weren t complicated enough 16 John Finn says 18 May 2005 at 9 21 AM I ve had climateprediction running on my computer for a few months but I m not sure I m getting my money s worth Why hasn t global dimming brightening shown up in the models Is this sort of thing beyond the predictive capability of climate science Sulphate aerosol features are not available as standard in current versions of climateprediction These will however be available in climateprediction version 3 7 1 22 which is due for release on April 1st 2006 It is possible though to get additional climate factors by downloading the Fudge Factor suite of plug ins absolutely free of charge Response JF is correct Maybe many people don t realise exactly what they are running from CP net If you look at http climateprediction net science strategy php you ll see that the existing runs are 15 years each of calibration pre industrial CO2 then 2 CO2 Phase 2 not yet available is simulations of the last 50 years but this requires a full ocean which is rather harder to set up and slower to run factor of 2 at least and possibly 4 William 17 Michael Tobis says 18 May 2005 at 12 55 PM Re 8 Scientists have gut instincts as much as anyone else but we know or at least ought to know better than to rely on them Sometimes nature takes us by surprise All scientists must always be vigilant about not letting our expectations color our results I think climate scientists should be especially scrupulous to avoid reporting our intuitions and having them enter into public discourse 18 Dave Dardinger says 18 May 2005 at 6 23 PM Since nobody else appears to have mentioned it let me throw out a possibilty which would combine the global brightening results with the recent finding that the earth s energy balance is off IR is absorbed in the top few mm of ocean but visible light is only absorbed at greater depths which depend on the exact wavelength Now if we ve had a recent post space age clearing in the atmosphere then there will be on average more visible light absorbed by the ocean Since this energy is absorbed at depth it will much more easily mixed with deeper water resulting in not being sent back to space OTOH additional IR from GHGs in the atmosphere will be largely used to evaporate more water vapor from the water s surface The net result is that the ocean surface will be absorbing more energy than it emits until such time as either more cloud cover occurs or when sufficient heat is absorbed to equilibrate the oceans to a higher temperature Response Solar does penetrate into the ocean but I suspect that the bulk of it is absorbed in the top say 10 meters Over a fairly large fraction of the ocean the mixed layer wherein the ocean is close to isothermal is deeper than this So that probably means that the solar stays close to the surface and is thermally in contact with the surface values Its also the case that we don t need anything else to explain the heat balance of the ocean being off that is already explainable Indeed any additional explanation would probably leave the balance off again William 19 Dave Dardinger says 19 May 2005 at 1 19 PM Oh my William I have to laugh at your supposed point Reread what you wrote and tell me it doesn t amount to We ve gotten the results we want let s quit while we re ahead This is rather an inside joke among skeptics concerning warmers but to actually hear one say it even if just as a slip of the tongue is risible However to pass on to the factual point could someone point to where we can find how mixing in the top layer of the ocean occurs and how fast It may well be that the top few meters of ocean mix quickly but even so that doesn t mean we re dealing with something which can be ignored After all the total amount out of balance is less than 1 watt M2 For instance might we assume that a given amount of solar radiation which penetrates to 5 meters is equally likely to mix downward to 10 meters as to rise to the surface Response Williams point is accurate The maximum penetration of solar radiation is down to about 80m but anyone who has ever done any diving will have noticed that most of the red and yellow parts of the spectrum have been absorbed even in crystal clear water by about 15m depth Mixed layer depths range from a few tens of meters in the tropics to hundreds of meters in the North Atlantic and so the penetration of solar radiation directly below the mixed layer is very small Heat gets into the mixed layer which mixes quite fast as a function of the wind and buoyancy forcing through long wave and solar radiation as well as through sensible heat Those heat anomalies effectively diffuses into the deeper ocean and that is what s being seen in the ocean heat content diagnostics gavin Response Rather than laughing you might be better off thinking We have a physically and observationally consistent theory and model for the radiation inbalance Why would we want to substitute for that a physically unrealistic mechanism If there was a puzzle needing explanation as for example the mid tropospheric temperatures then speculation looks more sensible William 20 Allen says 19 May 2005 at 2 42 PM A worldclimatereport com article approaches this topic with a mix of caution and dramatic statements on the potential implications See http www worldclimatereport com index php 2005 05 10 global warming something new under the sun Perhaps RealClimate could address some of the most visible interpretations that are popping up in response to these papers Thanks Response WCR perceptively notes that Obviously something is very wrong here but its probably their own analysis which makes the std mistake of assuming that these changes in direct solar translate directly into changes in the radiative forcing of the earth William belatedly signed 21 Dave Dardinger says 19 May 2005 at 4 01 PM Re Gavin s response to 18 Not having ever studied Oceanography I went looking to find out a bit about Bouyancy Forcing Found an interesting paper http opd apl washington edu dasaro FLOATTECH DAsaro01 pdf What I liked is a set of data at the bottom of page 8 which describes the contributions to buoyancy flux for various factors It shows Buoyancy flux is the sum of that due to short and longwave radiation and that due to sensible and latent heat fluxes Average values of these quantities are 41 22 4 and 27 W m 2 respectively This shows I think that more short wavelength radiation will produce more mixing while more long wavelength IR radiation for instance from more GHGs will result in less mixing It would seem to me that this difference in mixing should result in global brightening sending more heat to depth quite irrespective of how much short wavelength radiation is absorbed below the mixed layer Response Err no Any increase in heating from whatever source causes less mixing because it makes the surface more buoyant than before There is a slight difference in this effect because the solar radiation penetrates a little further in but since wind mixing is such a strong factor in practice this is not a significant effect However the changes in ocean heat content are not being driven by big changes in mixing depths they are mainly driven by the diffusion of heat anomalies at the base of the mixed layer and that is the same whatever the mechanism is for warming the mixed layer itself gavin 22 Steve Bloom says 22 May 2005 at 4 28 AM Re 20 Note that the principal writer for World Climate Report site is none other than Pat Michaels which means that the site is another member of the happy ExxonMobil family See http www exxonsecrets org html orgfactsheet php id 85 23 Ferdinand Engelbeen says 22 May 2005 at 9 30 AM With some delay Science needs two weeks to arrive in the library here I have read the different articles about global dimming and I must say I am confused First the magnitude of the changes These are enormous compared to what can be expected for the change in greenhouse gases and aerosols in the period of interest according to models About the suggestion that aerosols may be involved Although the emissions in Western Europe have sharply declined over 50 since 1975 the timing doesn t correspond to the decrease in insolation until 1990 and the recovery thereafter Neither does that correspond to the increase in solar radiation in Australia and Antarctica since 1990 where human made aerosols have no measurable impact Moreover the global emission of sulphate aerosols is near steady since 1975 but with a large shift from Europe and North America toward SE Asia This may be seen in the data of India but China with an explosively increasing industry shows increasing insolation Further more insolation also means less reflection of incoming light as good as by clouds as by the surface itself But that is contradicted by the earthshine measurements which measure how much visible light is reflected by the earth s atmosphere on the dark side of the moon These trends show exactly the opposite of what is measured at the surface and by earth orbiting satellites Further direct and reflected solar light is only one part of the balance downward IR radiation from water vapour and other GHG s and IR radiation from the surface water evaporation precipitation â all play a role in distributing energy from warmer to cooler places and what is received from the sun and emitted back to space Interesting is that in the 20N 20S even 30N 30S area the amount of extra solar energy on the surface 2 W m2 in the last decades is more than compensated by more IR radiance back to space 5 W m2 measured at the top of the atmosphere How the balance for the whole earth is is not known to me and I haven t found the data yet Thus what causes global dimming and back I suppose that most is by changes in water vapour as can be seen in data from the Alps The change in water vapour there is three times larger than expected from CO2 induced water vapour feedback by models and the downward IR radiation more than compensates for insolation losses It is impossible to distinguish between natural water vapour variability and feedback induced by CO2 But by searching for surrogate water vapour levels as indicated by discharge river flows there is no trend in the river Rhine figure 13 North Alps discharge but a solar cycle related trend in the river Po South Alps discharge â Thus probably induced by the prevailing SW winds from over the warmer Atlantic As the Swiss have surface based upward and downward IR measurements on different places between 370 m and 3580 m elevation in the Alps some of them equipped with several filters on different wavelengths of interest it should be possible to make a difference in trends between CO2 induced downward IR radiation and that induced by water vapour This may give a better indication of what happens in the atmosphere today Response Be careful that you don t compare apples and oranges Flux changes at the surface are NOT the same as flux changes at the tropopause the definition used for the forcings bar chart The surface numbers can be quite large and yet have little or no impact at the tropopause In the case of global dimming aerosols and clouds have an effect both at the ground and at the tropopause but the ground numbers are much bigger Secondly 1990 is not a magic turnaround date Instead it is the date that BSRN network was established to provide better quality data for these questions while the older data only went up to 1990 The Earthshine measurements are indeed contradicted by the CERES measurements presented by Wielicki et al Thus there is some more work to do on this I think that the Wielicki results have a better sampling and a simpler calculation however we will have to wait until the dust settles before coming to a conclusion However

    Original URL path: http://www.realclimate.org/index.php/archives/2005/05/global-dimming-may-have-a-brighter-future/ (2016-02-13)
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  • Climate sensitivity and aerosol forcings « RealClimate
    claiming there is some possibility of a large climate sensitivity above what is generally accepted by the climate modelling community 6 degrees C perhaps as opposed to a more standard range of 2 5C to 4C Maybe Andreae s results don t justify the big call to action large emissions reductions but surely you support that anyway based on a large suite of independently arrived at climate science results right Of course you do My point is that some recent reports e g the Ocean Acidification post based on the Royal Society Report here at RC call for drastic emissions cuts but don t seem to back that up in their conclusions What worries me is that as policy makers refuse to engage climate warming and the science scientists will come out with increasingly more desperate reports preliminary studies etc that exaggerate the danger and end up shooting themselves in the foot This would be ironic and tragic since the climate science results both empirically and hypothetically in models could hardly be more compelling It is almost impossible to imagine what change in our fundamental knowledge would overturn the current climate science consensus as last expressed in the IPCC TAR A climate sensitivity of 3C with a CO2 doubling is certainly scary enough for me 17 David Donovan says 10 Jul 2005 at 9 14 AM Re 6 7 I would like to add http geosci uchicago edu archer PS134 Info specifially on CO2 saturation can be found in Chapter 3 18 James Annan says 10 Jul 2005 at 9 30 PM 15 Steve I don t really want to flog this to death but Prof Andreae s comment seems directly tied to their central estimate of 6C warming by 2100 NewScientist makes that link The scientists cannot control every word that the press write but they can certainly make sure their press releases are less obviously misleading FWIW Chris Jones explicitly disowned the best estimate we have so far comment in the Nature News article but Prof Andreae did not reply to my email Make of that what you will Note that most of their scary graphs are based on the A2 scenario the most pessimistic of the 4 main SRES scenarios and all of the scenarios themselves are predicated on absolutely no action to curb GHG emissions We are already taking action Maybe not enough to some nothing realistic will never be enough but next time you see a scary set of extreme predictions remember that the worst ones are predicated on a future that we have already steered away from and which were hardly likely in the first place Bush may seem intransigent but remember that although a week is a long time in politics even a decade is a fairly short time in climatological terms That s not a call for inaction just a bit of perspective It s not fair of me to just pick on this AJC paper so for another example Tim Palmer quite clearly misrepresented the Stainforth et al CPDN paper in a public presentation at the Royal Society earlier this year Again the paper had the appropriate disclaimers but it looks like Tim Palmer decided to simplify things for the benefit of the audience so how are journalists and the public who don t even get to read the paper supposed to work out what it really means 16 Yes Dave that is exactly what worries me too increasingly shrill and exaggerated scaremongering from scientists who want stronger action They should be able to argue it on the case of 1 5 3C warming by 2100 which IMO seems to be our current course if they think that is serious enough Which it probably is but I m not really up on the impacts stuff FFS I m sounding like a sceptic here I m anything but 19 John Dodds says 11 Jul 2005 at 11 17 AM I do not understand the GISS Model IPCC implementation of the Enhanced Greenhouse effect I do understand that the solar energy in dictates the earthly energy out at equilibrium at the balance point at the Top Of Atmosphere 10 000m and that unless the solar in changes then the law of conservation of energy requires that the Stefan Boltzman derived 255 K temperature at equilibrium at this balance point can not change Also that the 4W m2 change to 1364W m2 or 0 29 in Solar energy in from 1700 to 2000 http www grida no climate ipcc tar wg1 245 htm would account for about 0 0029 x 255 K 0 75 degree absolute rise in temperature Also the IPCC says there is an uncertainty of 2 so this could easily account for ALL of the observed and real hockey stick rise in global temperature I think I understand why in theory changing the constituents in the atmosphere ie adding anthropogenic CO2 or the Enhanced GH effect could change the ability of the atmosphere to absorb outgoing energy see the Y Kushnir GISS IDEO Columbia U summer 05 lecture notes and slides http www ldeo columbia edu kushnir MPA ENVP Climate especially for absorbtion spectra and result in a change in the slope of the temperature gradient from the TOA to ground level and result in an increase in ground level temperatures ie GHG induced global warming It also seems that even though the selective absorption of specific energy bands by different molecules IS the mechanism to add energy to the air the energy absorbed by CO2 especially Water Vapor is extremely rapidly dispersed by molecular collisions to ALL the components of the atmosphere so that the N2 and O2 also heatup and all the atmospheric components assume a uniform temperature ie global warming I assume that the ultimate atmospheric temperature is then dictated approximately by the ideal gas law PV nRT at the different elevations and pegged to 255 K at the 10 000m TOA energy balance point Is this reasonable Response First the top of atmosphere for radiaitive purposes needs to be at least above the lower stratopshere and so 10km is way too low The GISS model top is closer to 50km The effective mean radiaitve equilibrium level is closer to 10km though but that doesn t imply that no other levels need be considered The outgoing radiation comes from all levels including the surface Secondly the range of solar changes from 1700 is from 0 05 to at the extreme end 0 5 however the potential range from 1850 onwards is smaller and since 1950 has probably declined or stayed steady The 4 W m2 solar constant change you quote which is at the high end is around 0 7W m2 in global annual mean radiaitve forcing compared to 2 4 W m2 from CO2 CH4 N2O still a small number Thirdly the ideal gas law is of course relevant but in the presence of external sources sinks of heat is used mainly to determine the density of the air at any point given the temperature and pressure What I do not understand is how the gas law limitations are imposed on the CO2 spectrally absorbed energy and how this is implemented in the computer models Question 1 IPCC Box 1 http www grida no climate ipcc tar wg1 011 htm says that adding CO2 results in the new CO2 absorbing more energy to create the anthropogenic GHG forcing heating up by taking some of the earth s energy out flux and then warming the atmosphere WHY does only the new CO2 heatup why not the old natural CO2 How can one specific segment of the atmosphere heatup more than another identical segment Since anthropogenic emitted CO2 comes out of a power plant stacks vehicle exhausts at an elevated temperature due to the trivial manmade waste heat energy and then cools down to near equilibrium with the rest of the atmosphere why would this new CO2 then absorb more energy and heatup again Wouldn t a CO2 molecule that absorbs an extra photon just reemit it to stay at the equilibrium temperature This simple IPCC description of the enhanced greenhouse effect just does not make sense Alternatively if the CO2 does absorb the extra energy up to its saturation limit then transmits it to the air by molecular collisions to achieve global warming then there is no limitation on the CO2 absorbing another photon ad infinitum which is obviously absurd The ideal gas law must impose the limitation on CO2 warming Response I don t understand your points here When the atmosphere warms up all the molecules warm up together There is no temperature difference between the new and old CO2 As extra CO2 is added more absorbtion occurs and more LW is radiated up and down This makes it more difficult for the surface to radiate to space and so the surface warms up to increase the flux of LW There is no gas law limit on GHG warming although there are limits related to lines saturating and the like Question 2 When CO2 is emitted there is also a larger amount of O2 that is removed from the atmosphere Ralph Keeling research the son of the recently departed Charles David of Keeling Curve fame For example if you burn a simple hydrocarbon or methane CH4 plus 2 O2 FROM the air you get energy plus CO2 TO the air plus 2 H2O to the ocean ie 2 O2 out is bigger than 1 CO2 in I would assume that the net change in density of the air in PV nRT ie a net loss of 2ppm yr of O2 has either a slightly negative or neutral impact on the temperature Also the net total quantity of molecules that are changed is a VERY small fraction 0 0002 of the total but it does decrease How is this limitation or possible decrease of temperature by the ideal gas law imposed on the amount of energy that can be absorbed spectrally by the new CO2 How does this show up in the GHG forcing function depiction of the earth energy flux balance How is it implemented in the GISS models Is the energy that is not absorbed by the missing O2 also accounted for in the models Response This indeed is a small effect but it is actually dwarfed by the bigger effect that changing water vapour in the atmosphere has on the pressure Some models include these terms but you need to get to really high CO2 levels before it s necessary to start adjusting the mean molecular weight of the atmosphere or any of the relevant constants Question 3 If the change in PV nRT due to the change in CO2 O2 concentration IS small negative or negligible then wouldn t you expect the change in temperature to also be small or negligible ie does a slightly lower density of air mean a slightly lower ground level temperature temperature normally decreases with height at the lower air density so that in reality adding CO2 and subtracting more O2 actually causes miniscule or trivial global COOLING and the unused ability of the changed atmosphere to absorb radiation energy and transmit it to the rest of the air is overruled or limited by the ideal gas law Response Changes in the atmospheric composition are negligible for their effect on the gas law but not in terms of radiative transfer so your conclusion is invalid If this is valid wouldn t it mean that adding CO2 does NOT cause global warming That the sun is directly responsible for the observed global warming It also resolves my problem with a solar forcing that can account for all the warming see above but also a GHG Forcing that is 10 times as large as the solar forcing and no warming left to be accounted for Something is fishy somewhere Common sense says that the sun causes daily yearly temperature fluctuations and changes in the sun and Milankovitch factors supposedly cause millennial ice age fluctuations It just seems strange that a few molecules of CO2 cause the 30 to 300 year changes Sorry Gavin but I am a skeptic looking for an explanation Response It may be strange but that s the reality There are a number of factors in the atmospheric composition that help determine surface temperatures UV absorbers ozone LW absorbers GHGs aerosols a little SW absorbers aerosols etc changes in any of these trace constituents change the underlying temperatures and all need to be thought about when trying to work out what has happened over the last century or so gavin 20 John Dodds says 12 Jul 2005 at 3 39 PM Thanks for the info response in 19 I DO appreciate your efforts I also apologize for not making my point clear so I am going to try again It may get repetitive since I will try to say the same thing several times from different perspectives Initially for the sake of a simplified discussion assume that we have an earth system with only solar energy and GHGs All other factors aerosols UV O3 etc are assumed constant We are at equilibrium temperature assumed to be 288K at ground level and 255K at the effective mean radiative equilibrium level close to 10km with Old preexisting GHGs in the air at the 380ppm level For the moment we assume that the solar energy in is held constant in order to isolate the GHG effects There is an addition of new anthropogenic GHGs CO2 on the order of 2ppm yr to the air In order to produce the new GHGs an assumed 4ppm of O2 is removed from the air to support the combustion process while generating energy in the power plant Ralph Keeling O2 data What I believe will happen is that the new GHGs will be released from power plant stacks vehicle exhausts at elevated temperatures due to trivial waste heat Because the new GHGs are at an elevated temperature they will NOT absorb heat energy from the air Energy will NOT flow uphill only from hot to colder objects In fact the GHGs will actually cool down by slightly heating the air by molecular collisions and result in the energy out flux slightly increasing by a trivial amount to exhaust this waste heat to space The new gases are assumed to cool to ambient equilibrium and the energy out flux is assumed to remain constant due to the trivial waste heat effects Response You have a basic misunderstanding which has been pointed out to you below but in which you seem to persist the temperature at which the CO2 is emitted is irrelevant becaause it quickly mixes into the atmosphere The old and new CO2 in an air parcel is at the same temperature Since all the rest of your assertions seem to depend on this mistake it s all wrong William At this point we have the question of the ENHANCED GREENHOUSE EFFECT to consider Per the IPCC Report Box 1 http www grida no climate ipcc tar wg1 011 htm the EGH Effect consists of the absorption of energy out flux by the newly emitted GHGs which then very quickly transfer the absorbed energy by molecular collisions to the rest of the air including the old GHGs The absorption of energy results in the GHG Forcing It is assigned only to the new GHGs because it is assumed that the old GHGs had already come to equilibrium with the air and the pre existing energy out flux prior to the emission of the new GHGs This is the basic cornerstone assumption for GHG induced global warming or stated another way The IPCC and GISS model assert that As extra CO2 is added more absorption occurs and more LW is radiated up and down This makes it more difficult for the surface to radiate to space and so the surface warms up to increase the flux of LW quote Gavin from response to 19 he writes better than I do I assert that there is NO Enhanced GH Effect above the gas law equilibrium point The new GHGs are at equilibrium temperature or actually cooling down from the elevated waste heat The new GHGs will NOT absorb heat energy by molecular collisions they will give it off By the ideal gas law PV nRT the temperature of the air has not changed significantly due to the addition of the new 2ppm of GHGs and the subtraction of the 4ppm of O2 used in the power plants The energy out flux will not change because the temperature of the air which dictates the flux level by Stefan Boltzman does not change we have assumed that the energy in flux is constant If the new GHG temperature is the same or higher than the air temp then there will be NO energy absorption by radiation by the new GHGs or any other air or GHG molecules Any absorption by radiation would result in the gases getting warmer than their equilibrium temperature They would immediately reradiate the energy to return to equilibrium conditions If the energy from the energy out flux is used to heatup the new GHGs in order to heatup the rest of the air then the reduction of the flux dictates by Stefan Boltzman that the air temp must be reduced However we have not reduced the air temp we have added absorbed energy to the GHGs thus increasing the air temp Thus taking flux energy to heat the GHGs air that dictates the flux energy is impossible and self contradictory The only way flux energy can heatup the air is if the solar energy in flux is increased to set a new equilibrium From a flux perspective If a photon of energy from the energy out flux does impact a new GHG molecule it will bounce off or be absorbed and immediately reemitted because the GHG molecule is already at the same equilibrium temperature or warmer from waste heat than the rest of the air There would be no increase in LW flux either up or down Absorbing a flux photon would raise the new GHG molecule temperature and the GHG molecule would immediately reject the photon to return to the equilibrium temperature Similarly if the photon hits an old GHG molecule which is at equilibrium it too would bounce off and not be absorbed because this is exactly what was happening to the air and old GHGs before the addition of the new GHGs Also note that if the GHG molecule did have the ability to absorb flux out energy and heatup the air it would be a perpetual motion machine because as soon as it absorbed radiated energy it would transmit it to the air by molecular collisions and then be able to absorb another radiated flux photon ad infinitum This is not possible Since all the gases are already at equilibrium any LW flux photon that is directed down will just bounce off until it bounces out to space There is no increase of LW flux or increase in ground air temperature The Enhanced GH Effects model for adding GHGs FAILS to account for the gases reaching equilibrium temperature per the gas law and then refusing to accept more energy absorption The ability of the GHGs to absorb more energy and vibrate more than O2 for example is NOT used If there is no new energy absorption by the new GHGs then the GHG Forcing is ZERO or negligible The addition of the new GHGs has a negligible effect on the air temperature per the gas law CO2 does NOT cause global warming Now consider SOLAR insolation energy In 19 it was claimed that the 4W m2 change to 1364W m2 or 0 29 in Solar energy in from 1700 to 2000 http www grida no climate ipcc tar wg1 245 htm would account for about 0 0029 x 255 K 0 75 degree absolute rise in temperature Also the IPCC says there is an uncertainty of 2 so this could easily account for ALL of the observed and real hockey stick rise in global temperature Gavin objected to the choice of 4W m2 increase as being on the high end which it is So I will modify it Assume only 3 W m2 so 3 1364 0022 or 0 22 But it is at ground level so this is multiplied by the 288 K ground temperature to get a 0 63 degree Absolute rise in temperature due to increases in solar insolation from 1700 to 2000 Same conclusion the solar insolation is within the range of being able to account for ALL the observed global warming Gavin also identified the time dependant inconsistencies between solar insolation and measured temperatures 1st response Secondly the range of solar changes from 1700 is from 0 05 to at the extreme end 0 5 however the potential range from 1850 onwards is smaller and since 1950 has probably declined or stayed steady I thought that we had already disposed of the fact that more recent temp data is rising faster than the solar forcing If you go back to the 1700 1750 time frame it was the reverse More solar forcing less temp increase This is exactly what happens on any no EVERY typical day see the online daily data from Luxembourg http meteo lcd lu today 01 html The earthly systemic lags make the temp lag behind the solar forcing In the 1700 1750 time I would attribute it to most of the heat going into the latent heat of warming the ice not the air temp In the later phases 1950 2000 I would say that the solar forcing is peaking the temp data is still rising and perhaps there is a heat reservoir in the ocean s 0 85 degree rise that is now forcing the air temps to lag behind and stay high In exactly the same way as on a daily basis the peak temp is in mid afternoon the peak solar forcing is at noon This time lag phenomenon is also evident in the ice age charts and according to this website is about 800 years This argument of inconsistent timing is not conclusive one way or the other just a complicating factor CONCLUSION Sorry Gavin my skepticism level is getting higher Your responses have just reinforced my skepticism I just do not believe or understand that one basic assumption IPCC Box number ONE that the enhanced greenhouse effect causes a significant increase in temperature If it is wrong then the whole GHG CO2 causes global warming issue has just been turned upside down CO2 will not cause warming Global warming will still exist it will just be caused by the sun So this is serious Please give this some serious thought As to your final comments that changes in any of these trace constituents change the underlying temperatures My thought is that trace constituents change sounds suspiciously like a butterfly flapping its wings in the Amazon causing a hurricane in the Texas Gulf While its true that a butterfly can move a few cc s of air it cannot manufacture energy out of nothing It was the sun that caused all the heat energy that caused the hurricane in the Texas Gulf The butterfly just happened to flap at the same time I think the enhanced greenhouse effect is as mythical as the butterfly effect Thanks for your time responses I appreciate all your efforts both in this website and in the extremely complex GISS model even if I think it has a flaw or two John Dodds San Francisco 21 Joel Shore says 12 Jul 2005 at 4 30 PM Re 20 Just on a very high level when one is coming into a new field and is discovering things that one doesn t understand it is best to assume at least tentatively that this is due to one s own ignorance on the subject and not due to the fact that the people who have spent their careers studying it are all wrong On a grittier level you are confusing yourself with totally irrelevant things The temperature of the released CO2 molecules is a negligible effect As an analogy if I told you that I was going to paint my white car black and that I expected it would get hotter on sunny days as a result you would probably start asking questions about what the temperature of the paint was when I applied it and how those molecules heated up or cooled down ignoring the relevant factor which is this By painting the car black I am changing the car s albedo and thus changing the radiative balance between the car and the sun on sunny days Note that in some sense you are right that it is the sun that matters Without the sun the addition of a little bit of heat and molecules to the atmosphere would have a negligible effect However the sun provides an abundant source of energy and by changing the earth s radiative balance so that we absorb a little more of that energy we are having an important effect on the earth s climate All your talk about ideal gas laws and what temperature the CO2 is emitted at are just irrelevant factors that are obscuring this fundamental fact 22 John Dodds says 13 Jul 2005 at 3 18 AM Re 21 Joel thanks for the advice I have been studying this for several years now Most of it is basic high school physics I have a masters in Nuclear Engineering so it is not difficult just very obscure and complex The real research what Gavin does includes alot of dreary drudge work the classic 1 inspiration 99 perspiration I have the greatest respect for what Gavin et al have done Hey they said we were in global warming when everyone else said you re crazy They were right That doesn t mean that they got it ALL right In most of my posts you will notice that they are in the form of questions eg see 19 above which Gavin very obligingly answers as long as I don t tell him he is wrong If you note his answer to my question 3 in 19 you see that he says I m wrong but doesn t say why I still don t understand why but I sure will NOT just take his word for it The physics has to make sense HOWEVER there are also hints eg the fact that there IS a major controversy over whether theIPCC computer model theory is completely valid or not the fact that there are a whole lot of people known as skeptics that says that something is just not quite right I m trying to find out what is not right At the moment my understanding of one little part of the physics probably a fraction of a tenth of a percent of the model conflicts with Gavin s IPCC That doesn t necessarily make Gavin IPCC right however the chances are pretty good that he is I ve also got the entire California legislature that legislated that water vapor is NOT a greenhouse gas even tho Gavin I and most of the scientific community say it is What I would like Gavin a bunch of understanding physicists to do is identify where my understanding in 20 is wrong and in doing so hopefully educate a few more people However the last time I said he might be wrong he stopped answering I think I frustrated him to death If he doesn t answer it is due to one of several things a He doesn t have the time or he thinks I m a kook and not worth answering or B I got it right he is afraid that my truth will completely eliminate much of the funding for his job I doubt B I thnk he has too much integrity for that For your technical comment yes the temp and energy of the released CO2 IS a very trivial item the value is insignificant I think it raises the actual air temp by about a millionth of a degree or so The fact that it makes the emitted CO2 HOTTER than its surroundings hence not likely to absorb energy from the cooler air is what is significant The hotter CO2 will cool down watch the gas plume cool from a power plant stack or a car exhuast not heatup so where I have a problem is with the IPCC enhanced greenhouse effect assumption that the released CO2 WILL absorb energy and heatup Why would just this newly released CO2 the source of the GHG forcing heatup and NOT the old preexisting CO2 that has been sitting around for years It just is a little bit fishy I want someone to explain it since I can t at the moment As for the ideal gas law being irrelevant it is the ideal gas law that dictates what the temperature of the air is ie the 288 K number which is also the temperature of the natural CO2 in the air What I do not understand is how this natural law can be ignored by heating up the CO2 to a higher level and violating I think this law Thanks for the interest at least someone is reading this 23 Chris Randles says 13 Jul 2005 at 5 18 AM James Re 8 I don t know about Nature and real climatologists but I was interested in Efficiently constraining climate sensitivity with paleoclimate simulations I only have a vague idea what an ensemble Kalman filter is and certainly don t fully understand it Nevertheless it occurred to me that the distribution of an ensemble found using an ensemble Kalman filter may become more circular than it ought to be What I mean by this is When you plot ocean heat uptake against climate sensitivity I get the impression that the distribution of good models will be a large clump around a climate sensitivity of 3 but then there is a long tail out towards higher sensitivities Does an ensemble Kalman filtered ensemble become more circular than it should be or otherwise include far too low a proportion of models in that tail I am thinking this could be similar to the role of priors For example Constraining climate forecasts The role of prior assumptions 24 Timothy says 13 Jul 2005 at 5 27 AM John Dodds 0 CO2 levels are increasing and also other GHG 1 If there is more CO2 in the atmosphere then more of the outgoing LW radiation will be absorbed by the CO2 2 Since less energy is being allowed out of the Earth system the Earth system will warm up 3 As the Earth warms up it emits more LW radiation and will eventually reach a new equilibrium Now the uncertainty in making climate change predictions lies in two areas Firstly feedbacks ie step 3 What other things in the Earth system will change when it warms up that will affect how much SW radiation is reflected back into space eg ice albedo feedback cloud changes or affect what proportion of emitted LW radiation is allowed to escape to space eg Water Vapour cloud changes Secondly how much CO2 and other GHG are we going to emit ie step 0 You appear to be questioning step 1 which is not in any doubt whatsoever It is an elementary result that can be reproduced in the lab Photons of the right wavelength will hit molecules of CO2 and they will be absorbed by them Quantum Mechanics If there is a greater density of CO2 molecules then the probability of a particular photon at one of these wavelengths that CO2 absorbs coming across a CO2 molecule is clearly increased As an addendum the reason that natural variability is often talked about is because the historical observed record is used to test and constrain the models and the assumptions that they have made about step 0 and step 3 but the natural variability creates a signal to noise problem If we had many centuries of good quality observations ideally over a period when the climate system was in radiative equilibrium then it would be much less of an issue As to specific points if the GHG molecule did have the ability to absorb flux out energy and heatup the air it would be a perpetual motion machine because as soon as it absorbed radiated energy it would transmit it to the air by molecular collisions and then be able to absorb another radiated flux photon ad infinitum This is not possible You are mistaken There are only a finite number of photons of the right wavelengths and not all of them will hit particular molecules since they are spread out Thus the ad infinitum part of your argument does not apply and there is no problem with CO2 absorbing radiation to take it above the temperature of the atmosphere That is the whole point If your reasoning was correct then there wouldn t be a greenhouse effect at all since absorbtion of radiation by GHG to warm the atmosphere could not occur since by your reasoning GHG molecules are not permitted to be even instantaneously warmer than other gas molecules due to abosorbtion of radiative energy Since the greenhouse effect does indeed exist 25 David Donovan says 13 Jul 2005 at 5 43 AM Re 20 Take for example a plume of CO2 emitted at sea level If it is hotter than the ambient air the plume is less dense than its surroundings and thus will rise As it rises it will cool as the pressure drops off note1 a consequence of the ideal gas law When the plume is no longer buoyant it will quickly start to mix in with the ambient air You have probably seen this happen for yourself looking at stack plumes especially on calm days After the gasses are mixed there is no practical difference between the temperature of the new and old CO2 The only place where different atmospheric gasses can be thought of to possess different temperatures is in the very high atmosphere edge of space where densities are so low that collisions between molecules are rare What the CO2 both cold hot and warm CO2 and other gasses do is to make the atmosphere more optically thick to thermal IR radiation emitted mainly from the Earth s surface note2 which has consequences for the equilibrium temperature profile of the atmosphere To a good approximation the Earth gets all its energy from the sun in the form of short wave solar radiation sun light Since the atmosphere barring clouds etc is largely transparent to many wavelengths of sun light if it wasn t we would have trouble seeing a good part of this radiation makes it to the surface and is absorbed That absorbed energy raises the temperature of the surface you may have noticed how hot some surfaces like road surfaces get in direct sun light Now all things emit radiation depending on their temperature note2 the higher the temperature the more the amount of emitted energy If there was no atmosphere the surface of the Earth would heat up until the amount of absorbed sunlight was balanced by the amount of energy lost by radiating thermal IR radiation to space In this case the temperature at which this would happen is considerably colder depending on the fraction of sunlight that is reflected and not absorbed at about 255K pretty chilly We would find also that the temperature difference between being in shadow or in the open would be pretty drastic take the moon for example In the presence of

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  • An Aerosol Tour de Forcing « RealClimate
    Bellouin et al based upon a single putatively representative site Yu et al use an even broader array of measurements and models Why do similar methods result in forcing estimates whose uncertainty ranges don t overlap This is difficult to know although here we speculate upon the effect of some of the differing assumptions Chung et al specify greater particle absorption compared to all but one of the six regional values used by Bellouin et al Because the TOA forcing becomes less negative as absorption increases this accounts for some of the difference Similarly Chung et al s replacement of their model estimate of anthropogenic particle fraction over the ocean with the MODIS estimate following Bellouin et al narrows the difference Treatment of aerosol forcing over cloudy regions also contributes to the difference Both studies estimate nearly identical forcing at the surface in the absence of clouds While aerosol absorption and reflection have opposing effects at TOA they both reduce sunlight beneath the aerosol layer contributing to negative forcing at the surface Thus forcing at the surface is less sensitive to the relative strength of absorption versus reflection When cloudy regions are included Chung et al calculate a much larger reduction of surface radiation than Bellouin et al who assume that aerosol forcing in these regions is zero At TOA Chung et al calculate positive aerosol forcing within cloudy regions accounting for some of the global disagreement with Bellouin et al TOA forcing depends strongly upon the relative position of the cloud and aerosol layer An absorbing soot layer above a bright cloud absorbs more radiation than if the layer were beneath the cloud Unlike AOT the vertical distribution of aerosols is not measured routinely and is comparatively uncertain The disagreement among forcing estimates raises the more general point of whether any study really captures the full range of uncertainty The number of calculations needed to sample the uncertainty can increase exponentially with the number of uncertain parameters While parametric uncertainty is straightforward to estimate the dearth of observations makes it difficult to estimate the effect of assuming a bulk absorption that represents an average aerosol rather than computing absorption by each species separately The latter is an example of a structural uncertainty that is typically difficult to characterize Given the difficulty of measuring the aerosol mass over the entire planet along with myriad aspects of the aerosol life cycle that are poorly measured and impossible to model precisely the most reliable estimate of forcing uncertainty may be derived by combining the central forcing estimate from a number of studies as opposed to taking the uncertainty range of any single study Yu et al seem to acknowledge the large outstanding uncertainty by relegating their estimate of anthropogenic aerosol forcing to a table rather than highlighting it in the abstract or conclusions Progress will come by more systematic comparisons among studies to identify key uncertainties The unambiguous distinction between individual aerosol species within models will eventually become possible by direct observation as a result of more discerning instruments Nonetheless models will remain valuable for their ability to distinguish natural and anthropogenic sources of the same aerosol species While Bellouin et al assume that all soot particles over the ocean are anthropogenic naturally occurring forest fires contribute as well As consensus emerges regarding the global aerosol forcing attention will turn to regional values that cause local changes to climate and heat redistribution by the atmosphere Because of the added complexity of cloud physics the aerosol indirect effect may be even more resistant to consensus Aerosol forcing remains a crucial problem because its offset of greenhouse warming is expected to decrease with time as governments address the health problems associated with aerosols Because of their comparatively short lifetimes the concentration of aerosols decreases much faster than that of CO 2 given a reduction in fossil fuel use Regardless of the absolute amount of the forcing future reductions in aerosol emissions will be a positive forcing amplyfying the warming effects of increasing greenhouse gases References Bellouin N O Boucher J Haywood and M S Reddy Global estimate of aerosol direct radiative forcing from satellite measurements Nature 438 1138 1141 22 December 2005 doi 10 1038 nature04348 pdf Chung C E V Ramanathan D Kim and I Podgorny 2005 Global anthropogenic aerosol direct forcing derived from satellite and ground based observations J Geophys Res 110 D24207 doi 10 1029 2005JD006356 pdf Yu H Y J Kaufman M Chin G Feingold L A Remer T L Anderson Y Balkanski N Bellouin O Boucher S Christopher P DeCola R Kahn D Koch N Loeb M S Reddy M Schulz T Takemura and M Zhou 2006 A review of measurement based assessment of aerosol direct radiative effect and forcing Atmos Chem Phys in press pdf Comments pop up 12 12 Responses to An Aerosol Tour de Forcing 1 Roger Pielke Jr says 8 Feb 2006 at 4 47 PM Good article This paper by Morgan et al is relevant here and suggests that the chracteristics of a scientific consensus can be a function of the methods used to arrive at that consensus http cdmc epp cmu edu survey htm ELICITATION OF EXPERT JUDGMENTS OF AEROSOL FORCING M GRANGER MORGAN PETER J ADAMS AND DAVID W KEITH Abstract A group of twenty four leading atmospheric and climate scientists provided subjective probability distributions that represent their current judgment about the value of planetary average direct and indirect radiative forcing from anthropogenic aerosols at the top of the atmosphere Separate estimates were obtained for the direct aerosol effect the semi direct aerosol effect cloud brightness first aerosol indirect effect and cloud lifetime distribution second aerosol indirect effect Estimates were also obtained for total planetary average forcing at the top of the atmosphere and for surface forcing Consensus was strongest among the experts in their assessments of the direct aerosol effect and the cloud brightness indirect effect Forcing from the semi direct effect was thought to be small absolute values of all but one of the experts best estimates were 2 Caio de Gaia says 8 Feb 2006 at 7 01 PM I don t get it The three forcings are equivalent at the two sigma level if you trust the error bars Note that the Chung et al 2005 and Yu et al 2005 have errors bars so large that the forcing could even be positive One could claim that there was a problem if there were a 3 sigma difference or higher I don t see any issue with these estimates The Bellouin value if you trust its error bar suggests that the true value should be higher 0 6 W m 2 The problem arises in the incident radiation at the surface How is it possible that three contributions that are consistent give estimates with error bars that are clearly disparate Either these papers are getting there error estimates completely wrong or the same assumptions do not apply in the three studies I don t have time to read the papers in detail now but I m quite interested to know how you explain this Response The uncertainty presented by Bellouin et al Yu et al and the IPCC represents one standard deviation In contrast Chung et al s uncertainty value represents the range of forcing estimates derived from their different sensitivity calculations see their Table 2 Whether or not the central forcing estimates of Bellouin and Chung are within two standard deviations of each other depends upon whose estimate of the standard deviation you accept The different standard deviations raise the question of whether the full range of uncertainty is really sampled by any single study The larger point is that although each study narrows the uncertainty calculated by the IPCC the studies when considered in aggregate span much of the original IPCC range Nonetheless each of these studies deserves credit for incorporating actual measurements of aerosol amount into the forcing estimate as opposed to the IPCC value which is largely based upon models As for forcing at the surface the Bellouin and Chung clear sky values are nearly identical the all sky values differ only because Bellouin et al assume for simplicity that forcing in cloudy regions is zero Hongbin Yu has informed us that in the final version of their article in press they replace their all sky TOA value with a clear sky value citing the uncertainty in estimating aerosol forcing in cloudy regions ron 3 Joel Shore says 8 Feb 2006 at 11 43 PM Re 2 and as a question to the writers of this piece Are the error bars shown in the figure meant to be 1 sigma error bars or are they say 3 sigma error bars 4 William A Atchley M D says 9 Feb 2006 at 2 08 AM I am not receiving e mail notices of new postinga Can you help me 5 Lynn Vincentnathan says 9 Feb 2006 at 5 42 PM I m wondering about naturally occurring forest fires mentioned as a source of soot CO2 Of course such fires have occurred I guess ever since there have been forests long before humans entered the scene But could some of these today be in part attributed to global warming Such as when GW causes more drought aridity or tree disease and then fiercer winds 6 Ferdinand Engelbeen says 9 Feb 2006 at 6 02 PM As I have commented many times on aerosols here on RealClimate and on the UKweatherworld discussion group it is not easy to give a complete oversight of all the doubts I have about aerosols In general I have the impression that the cooling effect of human induced aerosols is largely overestimated To begin with a back of the envelope calculation The largest cooling effect is supposed to be from sulphate aerosols Here we have a good example the Pinatubo which ejected 20 Mt SO2 directly into the stratosphere see for more details here That lasted 2 3 years until growing sulphate water drops fell out In contrast humans emit some 80 Mt SO2 yr lasting average only 4 days The Pinatubo caused a global temperature drop including water vapour feedback of app 0 6 K If one expects that there is virtually no difference in direct effect for stratospheric and tropospheric aerosols then the net primary effect of human SO2 emissions would be not more than 0 025 K But stratospheric changes may have a larger impact than tropospheric like changes in the jet stream position The effect of aerosols should be measurable in the regions with the largest change but they are not Not in Europe with an over 50 reduction since 1975 neither did Philipona ea find a positive change in insolation in their 2005 GRL paper neither in India where the tip is warming faster than the only station of the SH in the neighbourhood not under the smoke of increasing emissions Neither in ocean heat content where all oceans in the NH are warming faster than the SH parts if corrected for area while the aerosol load in the NH is larger The influence of sulphate aerosols probably is overestimated and or the influence of other soot aerosols is underestimated Which leads to questioning even the sign of the total aerosol effect Last but not least the Bellouin ea paper I have not read yet the other papers in detail need to be seen as a worst case scenario and probably was intended to give a maximum negative influence of aerosols to be used in climate models In fact interpreting all fine aerosols over land as anthropogenic by them is way too high From the IPCC gaseous precursors and solid aerosols the quantities involved are Anthropogenic around 560 Mt y less than 1 micron Natural around 350 Mt y less than 1 micron around 5300 Mt yr over 1 micron Thus even if these are not underestimates of natural VOC emissions and or natural fires the annual natural emissions leading to aerosols present already 38 of the total fraction of fine aerosols This is higher than the 28 error estimate of the authors Even more interesting are the recent findings that the aerosols found over land in the free troposphere are mainly of natural origin See the 2005 GRL paper of Heald ea The main points natural SOA secondary organic aerosols in the free troposphere are some factor 7 higher than anthropogenic the mass ratio SOA SOx SO2 sulfate aerosol is app 2 1 to 10 1 between 0 5 and 5 5 km altitude chemical transport models underestimate SOA s with a factor 2 at the boundary layer and up to 10 100 times in the free troposphere The natural free troposphere SOA already counts for some 10 of the total aerosol optical depth Add to that the amount of natural VOC aerosols formed below the boundary layer and other natural fine and coarse aerosols and also the sea induced SO2 and salt aerosols over land then we may safely conclude that the Bellouin study is a huge overestimate of anthropogenic aerosol influence In addition to restrictions of the upper bound influence of aerosols in climate models the upper bound needs to be reduced further probably more than halved more like what is found in the Chung ea study based on the presence of natural small size aerosols That has repercussions for GHG sensitivity too as aerosol cooling and GHG warming are tightly coupled see RC here which results in appreciable differences in projections of future climate 7 Caio de Gaia says 10 Feb 2006 at 7 22 PM Thanks Ron I finally got time to read the papers and there are indeed differences in the way uncertainties are computed but it s obvious that all estimates can be put close to 0 6 W m 2 So at the TOA the three approaches seem quite robust and the differences between the authors do not hint at a serious problem Well at least not until we get studies with smaller standard deviations And as you point out clear sky values are nearly identical this clears my doubts Incorporating the actual measurements seems to actually be working quite well well there is still the problem of cloudy skies Thank you for taking the time to present these interesting results I don t work in this subject and although interested miss some of the relevant literature and do not have time to read each paper 8 Urs Neu says 15 Feb 2006 at 8 20 AM Re 6 The effect of tropospheric aerosols on global surface temperature cannot be deduced so easily from the temperature effect of volcanic eruptions The comparison just of the amount of SO2 and summing up over the lifetime is too simplistic A good review about the volcano climate effect can be found at http www space edu papers Volcanoclimate pdf Two major points the optical depth depends on the size of the aerosols smaller aerosols have larger optical depth per unit mass Larger eruptions tend to produce larger aerosols Larger aerosols sediment out faster Thus the temperature effect of a volcanic eruption is not proportional to the amount of SO2 emitted into the stratosphere Volcanic eruptions lead to a heating of the stratosphere and alter stratospheric chemistry ozone depletion The alteration of stratospheric temperature distribution can alter atmospheric circulation patterns El Nino NAO which also influence global temperature Further it is neglected that in the stratosphere the aerosols are distributed over a much bigger area for geometrical reasons roughly about a factor of 3 5 than in the troposphere so you need more aerosols to get the same shielding effect it s not the same thing to put a parasol 2 m above ground or the same parasol 50 m above ground you won t get the same cooling effect Why should the same climate models that include the effect of sulphate aerosols reproduce the cooling effect of volcanic eruptions very well overestimate the effect of tropospheric aerosols by a factor of about 10 The claim that the effect of aerosol reductions should be seen one to one in the measurements seems strange The temperature effect of aerosols and ozone in the case of the Europe link alone is compared to the measured temperature which is the result of all effects together natural greenhouse gases etc Apples are compared to fruit salad The same for India and the oceans For the radiation measurements which show increasing shortwave radiation since the 1980s see http www realclimate org index php p 154 For the calculation of anthropogenic climate forcing the exact value of natural emissions or the discovery of new natural sources is not that much relevant because these emissions have been there before and do not change climate unless it is found that they have changed too on the discussed timescale 9 Chris Reed says 15 Feb 2006 at 9 29 AM With reference to Jones and Cox s UKMO attempt to broadly gauge the effect of sulphate aerosols Impact of uncertainties in sulphate forcing climate sensitivity and carbon cycle feedbacks on climate projections for the 21st century See http camels metoffice com MiscReport01 html I understand that the equation they used to produce figure 1 is based on a notion of climate system heat budget outlined in IPCC TAR here http www grida no climate ipcc tar wg1 344 htm 921 I assume that these results allow us to constrain the 2xCO2 temperature increase to the range 2 to 4 deg C Or in fact less As sulphate forcing is only a part of the overall aerosol effect So this seems to be further reason to doubt the possibility of the apocalyptic scenario presented by Peter Cox at the end of BBC s Horizon Global Dimming Although 2 to 4 deg C for 2xCO2 will probably still be very bad Response See our previous posts on this subject Global Dimming and Climate sensitivity

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  • Global Dimming and climate models « RealClimate
    away in the last years There are still lots of pollutants in the atmosphere in the US and Europe as well not just in Asia but less that ten years ago in many regions of the world And these pollutants still dim the sunlight and change clouds 11 frankhillis yahoo com says 18 Apr 2006 at 9 26 AM I apologize because this post is not directly related to the topic being discussed But I wanted to suggest a possible article topic to someone associated with this site A lot of mileage has been gained from the ice core samples in Greenland and elsewhere An expensive proposition by most scientific standards but small compared to say a military project What other information gathering initiatives could be funded right now to give us information How much would they cost and what would they be designed to determine Is there any discussion about implementing any of them This is a pretty large question and not designed to address any one person s area of expertise And I was most curious about projects that might take a large amount of funding say a billion or so US dollars please don t laugh I think it might be unrealistic but considering the possible ramifications 12 Alan says 18 Apr 2006 at 9 32 AM RE 9 I understand what you mean you get so used to the shills you start to habitually ignore some things When I first heard the dimming claim a while back I also thought it was an industry beat up this is not to say the skeptics haven t tried to twist it for their own benifit 13 Roger Hill says 18 Apr 2006 at 9 34 AM Watts in watts out I can only hear the Enterprise institutes of the world saying see pollution is just great more pollution will solve all of our problems Scotty beam me up Response I haven t heard any group proposing more pollution to offset CO2 It would be pretty dicey because 1 the geographical distribution of aerosol cooling is very different from GHG warming and 2 Aerosols have a lifetime of only a few weeks in the atmosphere so if there were a world depression that shut down polluting industry you d see the full GHG radiative forcing hit you within a few weeks Talk about abrupt change There have been other geoengineering proposals though Teller s group was proposing putting a ring of fine copper wire fragments in orbit to reflect some sunlight and there has also been talk of shading by mirrors in space As geoengineering goes these strike me as pretty fanciful compared to proposals to remove CO2 from the atmosphere by chemical processes and sequester the resulting gas That s pretty fanciful too but at least it can be tested on a pilot basis with current technology raypierre 14 Richard Harvey says 18 Apr 2006 at 11 04 AM Just a remark on a small typo The phrase the indirect aerosol effect the impact of increasing sulfate aerosol concentrations on cloud droplet sizes which make look cloud darker should read the indirect aerosol effect the impact of increasing sulfate aerosol concentrations on cloud droplet sizes which make look cloud brighter 15 Hank Roberts says 18 Apr 2006 at 11 08 AM 8 Mark how contrails work sum up both day and night effects Quoting below from this first quick Google result you can do better but this article s footnotes cites will lead you to more info http www sciencenews org articles 20020511 fob1 asp These thin clouds slightly cool Earth s surface by blocking some incoming sunlight but they moderately warm the lower atmosphere by trapping a portion of Earth s outbound infrared radiation DTR the difference between the day s high and low temperatures During the 3 day hiatus of air traffic the average DTR was a little over 1 C wider than normal even though the average DTRs computed for the 3 day periods immediately before and after that period were below normal areas of the country typically blanketed with aircraft contrails in mid September showed the largest changes in diurnal temperature range mostly from increased daytime high temperatures 16 Hank Roberts says 18 Apr 2006 at 11 17 AM 14 there is a typo but I believe clouds with larger droplet size do look darker threatening rain clouds typically do Can t cite that at the moment though 17 Beate says 18 Apr 2006 at 11 45 AM Just a brief clarification to 14 the indirect aerosol effect the impact of increasing sulfate aerosol concentrations on cloud droplet sizes which make look cloud brighter darker This actually is not a typo From the satellites perspective clouds look brighter famous ship track image because they reflect more sunlight back to space But from the surface point of view these clouds look darker And since we talk about dimming at the surface I chose the word darker 18 Sean Houlihane says 18 Apr 2006 at 11 47 AM This is remarcably well timed given the accuracy of the BBC s climate prediction experiment which seems to have actually given some insight into the effectiveness of attempting to model a complex system Question If the program had not actually crashed in 2013 would the results have been believed 19 Merry Maisel says 18 Apr 2006 at 12 29 PM wrt 14 which make look cloud is simply not English Although all posters have ignored it could the original writer re render this sentence in standard English Is it makes clouds look appear brighter or dimmer If English is the language of science let s use English English has standards also easy to look up and verify including idiomatic word order and agreement in number tense and case Thanks Merry 20 Bryn Hughes says 18 Apr 2006 at 12 52 PM Actually the BBC programme stated that Global Dimmming was caused by Jet Aircraft Con Trails The number of these con trails has increased steadily since 1960 There was an increase in diurnal temperature range by 1 degree centigrade over the USA immediately after 9 11 when all aircraft were grounded for 3 days with the days being warmer and the nights being cooler Dr David Travis Wisconsin U Haven t sulfate aerosols reduced in recent years Weren t they the cause of the cold spell in the 1960s 21 SqueakyRat says 18 Apr 2006 at 2 13 PM Congrats to RC and Gavin Schmidt on the attention in Nick Kristof s slightly silly though well intended column The piece is behind the NYTimes subscription wall but includes a link to RC You guys are starting to make a difference 22 Dan says 18 Apr 2006 at 2 40 PM re 20 A change of 1 degree C in the diurnal range in the immediate days after 9 11 may have also been simply due to the synoptic pattern A relatively dry Canadian high pressure system was over a large portion of the country which could have easily caused a larger diurnal range 23 Don Baccus says 18 Apr 2006 at 2 47 PM 21 I fear that Kristof s column though well intentioned may backfire He quotes some of the wilder speculation about methane clathrates that were in the piece that appears at Real Climate with just a hint that these outcomes are thought to be extremely unlikely Of coures he states that he s enganging in a bit of hyperbole actually he says fearmongering but he s given the other side a lot of opportunity for quote mining Response On the contrary Kristof did an excellent job of pointing out methane clathrates as an attention getting possible catastrophe which is possible though highly uncertain He states very explicitly that the more certain consequences of global warming ought to be sufficient to get action and it seems pretty clear that what he is really lamenting is the necessity to claim the end of the world before you can get any attention from the government Heck even when you do claim the end of the world and make a good case for it you don t always get action Kristof s campaign to get the world to do something about Darfur where the world has indeed ended for millions of people is a case in point As for quote mining the dark side of the Force is so good at quote mining that if people worried about that they d never say anything raypierre 24 Barton Paul Levenson says 18 Apr 2006 at 3 34 PM with regard to 19 and wrt 14 which make look cloud is simply not English Although all posters have ignored it could the original writer re render this sentence in standard English Is it makes clouds look appear brighter or dimmer If English is the language of science let s use English English has standards also easy to look up and verify including idiomatic word order and agreement in number tense and case Thanks Merry Why you which make look cloud not equals like For have perfectly good can understand meaning of sentence is the same Also Response Ah wise guy Master Levenson is yoda 25 Paul Duignan says 18 Apr 2006 at 4 21 PM Regarding the response to 13 As geoengineering goes these strike me as pretty fanciful compared to proposals to remove CO2 from the atmosphere by chemical processes and sequester the resulting gas That s pretty fanciful too but at least it can be tested on a pilot basis with current technology Any comment on the amount of energy this would take What if a large part of the remaining oil reserves were used to do this Would that have any chance of making a difference 26 Matt Middleton says 18 Apr 2006 at 4 30 PM So then do you still believe that the claim in the program of a global temperature increase of 10C is still outlandish or do you believe that this is now in the range of possibilities 27 Hank Roberts says 18 Apr 2006 at 4 33 PM Using an irreversible fix for a problem that s due to variables seems ill advised If a wild card comes up the sun gets a bit cooler or the solar system moves into some interstellar dust cloud or one of the dust rings orbiting along with Earth has a thick spot develop affecting us it d be a lot easier to uncork sequestered CO2 or burn coal than to fine tune a belt of orbiting shade dust or adjust a sunshade at L1 I bet Lagrange 1 point is unstable a sunshade there would need adjustment every 23 days or so http map gsfc nasa gov m mm ob techorbit1 html Dust in space http www journals uchicago edu ApJ journal issues ApJ v508n1 37785 37785 html erFrom 6702582451745181789Guest sc4 2 2 Of course I d love to see NASA have the capability but let s fiddle with Venus first okay Once it s on the way to being successfully terraformed that s soon enough to make astronomical sized changes to Earth 28 Barkley Rosser says 18 Apr 2006 at 4 47 PM One aspect of this involves longer term trends The environmental Kuznets curve phenomenon is relevant here in that higher income countries tend to reduce their emissions of both aerosols and suflates although these are still rising in the very important countries of China and India sources of so much controversy in the Kyoto negotiations But in the US and Western Europe and Japan they are definitely declining OTOH CO2 is known not to decrease as income rises and continues to increase in emissions and certainly in ambient quantities I have even seen speculation that part of what turned around the rough cooling between the 1930s and 1970s and turned it into the more recent warming trend was this switch as the richer countries started to cut back the cooling aerosol sulfates but continued to increase CO2 although if the numbers reported in above are correct it would seem that the cooling was not strong enough to be responsible for that BTW on an earlier post I noted the issue of the nature of the nonlinearity of GHG amounts to warming which is logarithmic Raypierre reported it is in the models which I knew The issue was the values of the parameters and how they interact with other effects going on One of these indeed is this sulfate aerosol cooling which is well covered here However that raises the issue that Raypierre reported it to be linear on top of the presumably logarithmic CO2 effect Is it linear How well understood is this 29 Ferdinand Engelbeen says 18 Apr 2006 at 4 54 PM Beate Although there may be more understanding of what aerosols are doing I still have a lot of unanswered questions see here which make me rather skeptic about the overall cooling effect of aerosols as currently implemented in climate models If tropospheric human made sulfate aerosols have the same physical properties as stratospheric volcanic ones the overall primary cooling effect would be around 0 025 K which is not very impressive I didn t find an explanation for any difference in properties in the literature I didn t find a measurable effect on temperature trends between less and more polluted areas in Europe as result of the large reduction in sulfate emissions Raypierre did give a reference to a study but that is behind a rather expensive issue fee wall Aerosol emissions are largely in the NH but warming of the oceans is far higher in the NH if corrected for area There is very little exchange of aerosols between the NH and SH Aerosol emissions are largely in the NH but global dimming was also measured in Australia and down to the South Pole My impression is that much of the global dimming is water vapor related not aerosol related Response If you think that perhaps you can tell us what water vapor shortwave absorption bands have been missed in the past century during which the spectroscopy of water vapor has been extensively studied Or did you perhaps mean clouds rather than water vapor directly I wonder how you are distinguishing between aerosol effect and cloud effects due to the indirect aerosol effect raypierre 30 Ferdinand Engelbeen says 18 Apr 2006 at 5 20 PM Re 3 comment Gavin according to the graph in Wild ea in Science in Asia most India stations see an increased dimming while most China stations show decreased dimming While this may be attributable to increased aerosols in India for China this is hardly the case And in Climate sensitivity and aerosol forcings the range of aerosol forcings is directly connected to the doubling CO2 sensitivity of 1 5 4 5 K Of course that are the ranges for different GCM s but I suppose that if one changes the aerosol forcing in one GCM the result would be a change in 2xCO2 sensitivity too 31 ocean says 18 Apr 2006 at 5 24 PM Ok what is the difference between the cloud effect and the aerosol effect Response The direct aerosol effect arises from the radiative influence of the tiny aerosol particles themselves sulfate droplets soot particles mineral dust etc The indirect aerosol cloud effect arises from the role of aerosols as nucleation sites Certain aerosols can make the typical drop size in clouds get smaller resulting in a more reflective cloud In addition climate change whether due to CO2 increases aerosol forcing or anything else will generally cause the cloud properties to change regardless of what aerosols do to cloud particle size This would also cause a change in the amount of solar radiation reaching the surface raypierrre 32 Bryn Hughes says 18 Apr 2006 at 6 32 PM Re 22 But the skies were clear of vapour trails surely that was the main cause of the change throughout the USA rather than your theoretical synoptic pattern Dr Travis is a good enough climatologist to recognise if such a pattern had caused the increased range and would have come to a different conclusion than the one he arrived at 33 Ferdinand Engelbeen says 18 Apr 2006 at 6 55 PM Re 29 comment Indeed Raypierre I meant water vapor and clouds but I am not sure what is more important As far as I have read most insolation measurements are done over a broad range of short waves as energy input without looking at specific absorption bands but I may be wrong If water vapor increases absorption in the near IR will increase and thus affect the overall incoming energy Do you have information about stations which have done long term spectroscopy measurements of incoming sunlight If clouds are involved that can be from aerosols or from natural internal or forced variability The secondary effect of less aerosols on clouds would be in the higher latitudes for Europe and North America where the radiation balance doesn t change much with more or less clouds according to Philipona The increasing SE Asian aerosol emissions are at low latitudes which should increase tropical cloud albedo and lifetime but the recent trend in the tropics is that there are significantly less clouds Together with the global dimming and reverse in Australia and the South Pole this points to a non aerosol probably natural origin Response So far as I am aware there are no long term high spectral resolution time series of the solar radiation but last time I checked the water vapor molecule had not changed much over time Based on that I m pretty willing to trust laboratory spectroscopy It would take a darn huge overlooked band to give you the kind of signal the global dimming folks are seeing NO2 on the other hand has important solar absorption bands and in

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  • Current volcanic activity and climate? « RealClimate
    been any time in the past 3 5 billion years Using the Walker Hayes and Kasting weathering model with the present solar constant a 6Gt per year outgassing would equilibrate at an atmospheric CO2 concentration of about 57 times the present or 17000ppmv That would lead to temperatures in excess of 14K warmer than pre industrial values raypierre 17 gringo says 16 May 2006 at 10 33 PM Do you think that this and the erruption of Ubinas in Peru will have an effect on the hurricane season Sorry if this may be a stupid question I m not an expert 18 djv says 17 May 2006 at 12 07 AM Re 6 and 2 Thanks for the info on tectonic carbon sources though what s MORB Mid ocean ridge basalt I think the variations in atmospheric CO2 after the annual cycle and trend of course are dominated by ENSO As I understand it the tropical Pacific is a source for atmospheric carbon due to upwelling of cold carbon rich waters from deeper in the ocean along the equator During ENSO events that upwelling decreases considerably The early 1990 s were characterized by a series of El Nino events though there has been a good deal of debate over how to characterize the early 1990 s If you look at 1982 and 1997 from the Mauna Loa record link above you ll see similar slowdowns in the rate of CO2 increase Richard Feely at PMEL has an article in Nature also online at http www pmel noaa gov pubs outstand feel1868 text shtml that attributes 1 3 of the decrease in CO2 increase got it during the 1991 1994 autumn to autumn seasons to ENSO They estimate a 0 6 Gt C decrease in sea to air carbon not CO2 flux in 1992 due to ENSO There are also some nice model results by Galen McKinley and collaborators that describe the Pacific influence GRL 2004 Glob Biogeochem Cycles 2004 http www aos wisc edu 7Egalen 19 Ken Johnson says 17 May 2006 at 12 32 AM Maybe the biggest effect of volcano s on atmospheric CO2 is not their direct carbon dioxide release but the effect of the iron aerosols on primary production in the ocean Andy Watson has made the argument that atmospheric carbon dioxide decreased following the Pinatubo eruption because the iron in the volcanic aerosols fertilized the equatorial Pacific and led to increased rates of phytoplankton uptake of carbon dioxide Watson A J Volcanic iron CO2 ocean productivity and climate Nature 385 587 588 1997 20 Edward Greisch says 17 May 2006 at 1 29 AM There is one anthropogenic source coal fired power plants we could fix with well known technology if we could cure the common person of paranoia concerning things nuclear The average person has never heard of background radiation See articles by Alex Gabbard Oak Ridge National Lab concerning the uranium arsenic thorium etc in coal Oak Ridge National Laboratory REVIEW Volume 26 Numbers Three and Four 1993 Coal Combustion Nuclear Resource or Danger by Alex Gabbard You can download a version of it at http www ornl gov ORNLReview rev26 34 text coalmain html but it may hav been modified by a George Bush political appointee I was unable to paste a copy of the original here The paste didn t work 21 Andrew Dodds says 17 May 2006 at 8 42 AM Re 2 I suspect the skeptic reasoning goes like this a Mt Pinatabo SO2 releases were I believe comparable with human SO2 releases for a year This is then mistranslates as b Mt Pinatabo released as much pollution as humans release Which is then further scrambled misconstrued as c Mt Pinatabo released as much pollution as humans have ever released Which by simple if completely incorrect substitution becomes d Mt Pinatabo released more CO2 than humans have ever released And then claim d is bounced around all the usual suspects ad nauseum 22 simpleton says 17 May 2006 at 9 39 AM Silly and slightly off topic question would it be possible to reproduce the climate cooling effects of a volcano with one or more thermonuclear airbursts near the equator preferably in an unihabited area like the middle of the Pacific I ve read that there are some cooling spikes in the temperature records from around the same time as the 62 nuclear tests presumably because these kicked up a globally signifigant amount of aerosols into the stratosphere Presumably we could do even better if we specifically optimized thermonuclear airbursts for maximum climate cooling effects e g adjusting the height of the explosion changing the quantity and quality of dust to be vaporized Heaven knows there is no shortage of bombs available for such tests I understand that 1 interfering with a system as critical and poorly understood as climate is A Bad Idea 2 sulfate aerosols would catalyze a lot of ozone destruction and 3 a bunch of H Bomb tests may well have unfavorable political consequences But the alternative may well be hundreds of millions of at risk of death or even a James Lovelock Revenge of Gaia or runaway greenhouse scenario Might it be at least studying the feasibility of such a contingency plan It seems to me objection 1 could be overcome with a series of increasingly large tests comparing observations to model predictions Would it be possible to optimize thermonuclear explosions to get some cooling with an acceptable amount of ozone loss 23 lisa brooks says 17 May 2006 at 10 37 AM RE 7 Thanks Nick for the great link Very informative 24 Grant says 17 May 2006 at 11 47 AM Re 18 It s true there were slight dips in the growth rate of atmospheric CO2 around 1982 and 1998 but they re nothing like the dip around 1991 Also wasn t the 1998 el Nino a very strong one But the dip in CO2 growth rate wasn t comparably strong I m guessing only that while el Nino affects CO2 growth rate something else happened around 1991 to make the dip so severe The collapse of the Soviet economy seems a plausible reason and the coincidence with Mt Pinatubo is suggestive 25 Hank Roberts says 17 May 2006 at 1 26 PM Yes you can find documentation of the total fossil fuel burned year by year that confirms CO2 release by the former USSR states dropped dramatically that correspond to the observed growth rate measured in the atmosphere No time to look it up for you right now but it shouldn t be hard to find 26 Jeffrey Davis says 17 May 2006 at 4 58 PM Re 22 We ve noted before that it seems only a matter of time before one desperate scheme after another as long as it doesn t involve reducing the amount of fossil fuel we burn will be proposed Eventually one or more of them will be funded and carried out 27 David B Benson says 17 May 2006 at 5 04 PM Mt Toba last two eruptions Here is what I could find despite all the mis information out in webland Wikipedia says the last occured 71 000 years ago with a 4000 year error bar Another site states 73 000 with the same error bar Still another states 74 000 years ago No matter the following article claims that the global temperature dip for this massive event was about 1 degree C not the 2 3 usually claimed http forum palanth com index php topic 77 msg452 The following book chapter attempts to match Mt Toba dates to ice core data http www andaman org BOOK originals Weber Toba ch4 climate textr4 htm Finally this last paper states that the previous Mt Toba eruption led into a period of global warming not cooling http www nature com news 2004 040112 full 040112 17 html So my amateur reading of all this is that outside of South Asia the last Mt Toba eruption was about like the events of 536 8 AD only about twice as long Further the long term climate record basically ignored this event instead following orbital forcings Incidently one might attempt to read into human gene flow data Alan Templeton Yearbook of Physical Anthropology recent that Mt Toba erupted about 75 000 years ago again with substantial error bars 28 C W Magee says 17 May 2006 at 10 18 PM Yes MORB is Mid Ocean Ridge Basalt Gavin I think there is one significant factor that you have neglected to mention with regards to the ability of a volcano produce climate effecting arosols The sulfur content of the magma El Chichon and Pinatubo are both unusual in that the lava crystalized anhydrite CaSO4 in both eruptions indicating a sulfate saturated or near saturated magma 29 Blair Dowden says 19 May 2006 at 8 18 PM Re 7 and 16 The Volcanic Contributions paper from Nick Riley does not agree with the figures on CO2 emissions from ocean spreading centers given by C W Magee The paper claims 97 Mt yr CO2 about 33 Mt yr C which seems low especially when they claim 25 Mt yr CO2 for Mt Etna alone compared to 0 6 Gt yr which at 10 of human emissions seems too high Is there that much uncertainty or does someone have it wrong I am interested in the idea that the rate of volcanic emissions determines whether the Earth is a warm period eg Cretaceous or cool period I have read that even flood basalt eruptions only produce 1 or 2 Gt yr of carbon which does not seem a lot By the way surely the statement from the paper that Even during extraordinary times in the geological past such as the eruption of flood basalts eg the Deccan Traps 66 Ma the estimate CO2 emission is estimated to be only 0 3 2 Mt yr is an error they must mean gigatonnes They also point out that the increased area of continental basalt plays an important role 180 Mt yr CO2 in removing carbon dioxide This may be less significant for sub ocean basalt eruptions The point is I am having a hard time understanding how volcanic activity could create a warm period lasting 50 million years Flood basalt eruptions do not last that long They also have cooling effects aerosol emissions and basalt area and the paleotemperature record does not seem to correspond that closely to these events Is it possible that ocean spreading was that much more active than during other periods The numbers just do not add up for me 30 C W Magee says 21 May 2006 at 3 59 AM Blair can you post a full ref for that paper I can t read literature at home but I can look it up during my lunch break tomorrow Note that the calcs I did were a rough If you are really curious about this you should look up what the total spreading center crust production actually is it should be a fairly easy number to find and b My calculation only gives the total mass of CO2 that 1 year worth of magma contains How much of that is actually released requires some knowledge of the mid ocean ridge structure tectonics and fluid flow c If you want to calculate co2 contributions for LIPs you can do the same sort of calculation CO2 content total mass formation time only make sure you look up the CO2 content since I seem to recall perhaps incorrectly that hot spot magmas are generally higher in H2O and lower in CO2 than MORB 31 Blair Dowden says 21 May 2006 at 2 57 PM The Nick Riley paper is here Chapter five is the most relevant to this discussion and says the extrusion rate at mid oceanic ridges is 20 cubic km year To answer my own question about the Cretaceous I found this paper which says The Cretaceous was a time of unusually high rates of production of oceanic crust both at spreading centers and through the eruption of Large Igneous Provinces LIPs and The volume of crust produced by LIPs in the Cretaceous was almost three times greater than in prior and subsequent time periods So there is a credible source for a carbon dioxide forcing leading to a warm climate What part is played by heat transfer from the equator to the poles due to the different arrangement of continents is not clear Response On the other hand David Rowley s work over the past few years has made a pretty convincing case against major long term variations in the sea floor spreading rate If that holds up some other idea about the driver of long term CO2 changes must take the place of the M O R outgassing variations Ideas in play include weathering rate changes due to change in continental position or weatherable rock exposure and changes in the amount of sea floor carbonate that gets recycled through subduction It s a subject that is very much in flux just now raypierre 32 Hank Roberts says 21 May 2006 at 5 02 PM Thanks for giving the reference Looking at that Nick Riley says on the same page 5 citing other authors work that I haven t looked up that hydrothermal alteration of the newly produced lava is a sink which takes up effectively all of the CO2 produced along the midocean ridges The sink and source both vary in proportion to the changes in activity and fresh lava produced So his sources say that changes in mid ocean ridge activity would have little effect on atmospheric CO2 33 C W Magee says 22 May 2006 at 4 19 AM It appears that I significantly overestimated the co2 content of MORB since my total magma estimates are in the same ballpark 70 The way they get that concentration is a bit convoluted but seems to make sense The point of course is that even with an overestimate volcanic CO2 is 34 David B Benson says 22 May 2006 at 2 43 PM Re 10 27 More on Mt Toba From I N Bindeman The Secrets of Supervolcanoes Scientific American 294 4 2006 Jun pp 42 43 In 1996 investigators studying ice cores from Greenland and Antarctica found the sulfuric acid peak that followed the supereruption of Toba 74 000 years ago That eruption ejected 2 800 cubic kilometers of lava and ash and reduced average global temperatures by five to 15 degrees C The consequences of such a chill were undoubtedly severe but did not last as long as once thought sulfuric acid in the ice record disappeared after only six years some reserchers suggest that it vanished even earlier All this is well and good except the astounding 5 15 K cooling This doesn t agree with what I found and reported in 27 above Surely a 5 15 K cooling ought to produce quite a spike in the ice core records even at the scale of the book chapter I found and reported in 27 above It appears to me that somebody slipped a decimal point Then 0 5 1 5 K agrees with what I found and reported previously I would greatly appreciate some assistance here before suggesting this possiblity to SciAm and Dr Bindeman I am just an amateur regarding paleoclimate Advice please gavin Response I agree 5 to 15K sounds extremely unlikely I suggest emailing Dr Bindeman and asking for a clarification or a source I would point out that a global cooling of 15 K is about 3 times larger than the total ice age cooling at the LGM compared to modern gavin 35 Hank Roberts says 22 May 2006 at 3 32 PM I found one secondary source here http forum palanth com index php topic 77 msg492 That quotes from the abstract of this article Oppenheimer Clive 2002 Limited global change due to the largest known Quaternary eruption Toba 74kyr BP Quaternary Science Reviews 21 14 15 1593 1609 estimates of the sulphur yield of the erupting magma central to predictions of its atmospheric and climatic impacts vary by two orders of magnitude 3 5 330 units mangled by HTML Previous estimates of globally averaged surface cooling of 3 5 C after the eruption are probably too high a figure closer to 1 C appears more realistic The volcanological uncertainties need to be appreciated before accepting arguments for catastrophic consequences of the Toba super eruption 36 Blair Dowden says 22 May 2006 at 10 00 PM Re 31 Ray surely the subduction rate is tied to the ocean spreading rate so why would the rate of carbonate removal change About changes in continental position that is one reason given for the reduced temperature gradient between the equator and polar regions although not sufficient in itself But does this low temperature gradient itself cause a warming effect The Stefan Boltzmann law implies the Earth radiates energy proportional to the fourth power as its temperature If the temperature gradient increases am I correct to infer that the warmer areas will radiate more additional energy than the cooler areas will lose so the Earth must cool to return to equilibrium Conversely reducing the gradient will cause to Earth to warm If this is correct can you tell me how much difference this effect makes 37 Blair Dowden says 23 May 2006 at 6 59 PM I compared a world with a uniform 288 K temperature with one divided into two halves of 273 K and 303 K and calculated a 2 difference In the real world the change in distribution will be nowhere near that so this really is a non issue If I am right about it in the first place 38 laura says 24 May 2006 at 8 01 AM Oh thanx for the information I dint knew that Do

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  • Aerosols: The Last Frontier? « RealClimate
    passive solar home that uses only a fraction of the gas electricity of a comparable home that s without PV panels Considering all the homes buildings now going up WITHOUT even the passive techniques that don t have additional costs that have been known about and practiced for over 2 500 years see http www amazon com golden thread years architecture technology dp 0442240058 Today s home are flagrantly inefficient it seems like a big job to get architects to change habits And then those wrongly built houses buidlings are here for decades to come It really breaks my heart that at the first whiff of a problem the 70s energy crunch the field of architecture didn t completely or even somewhat embrace passive solar techniques 18 PHE says 21 Feb 2007 at 4 49 PM Wow aerosols remain the least understood component of the climate system Aerosols have a net radiative forcing of 1 2 W m2 against a CO2 forcing of 1 66 W m2 If I were an AGW convictee the closeness of these figures along with the uncertainty regarding aerosols would concern me 19 Marcus L says 21 Feb 2007 at 5 01 PM Good article But I do have to echo 10 what exactly does low level of understanding mean I take it to mean that we re pretty sure about the direction of net forcing due to aerosols is but we need more information to pin down the magnitude Is this pretty accurate The reason I ask is because the length of the error bars in the low understanding categories vary a lot Re 11 I m confused about why you d expect this article to address C02 as a greenhouse gas There is plenty of information on this website about that topic You clearly intended to say something with your questions but I don t get it 20 Paul M says 21 Feb 2007 at 6 12 PM Scientists are acting as enablers this is a social issue not a scientific one I think scientists should show the world some tough love 21 salamander says 21 Feb 2007 at 6 37 PM Re Post 20 by Paul M I think scientists should show the world some tough love Paul that s a very astute comment Thank you 22 Blair Dowden says 21 Feb 2007 at 7 53 PM I would like to know the calculation behind this part of the article A CO2 molecule has a lifetime of about 100 years in the atmosphere while an aerosol particle has an average life expectancy of only about 10 days Therefore if we instantaneously ceased using combustion engines the cooling fossil fuel related aerosols would be cleaned out of the atmosphere within weeks while the warming CO2 would remain much longer leaving a net positive forcing from the reduction in emissions for a century or more First I think it is more accurate to describe the lifetime of CO2 as half will be gone in 20 years while 20 will remain in the air for centuries at least according to this I would phrase the question as comparing the impact of running a coal plant for 100 years compared to replacing it with a clean energy source The aerosol forcing of the coal plant will remain constant over the century while the carbon dioxide impact will gradually accumulate The key values which I do not know are the forcings from the amount of aerosol and CO2 emitted from the plant I find it surprising it takes a century of CO2 emissions to catch up to the aerosol forcing It means that any action we take to reduce CO2 emissions will be effective on a longer time scale than I thought which was already long and the net effect will be less Response That s exactly right Juliane got that part wrong We ve been trying very hard to set the record straight It is wrong to say that a CO2 molecule has a lifetime of about 100 years in the atmosphere It takes more like 500 1000 years for the ocean to remove 80 of the Co2 and there s a tail that extends for at least 10 000 years Don t know how we overlooked that but c est la vie See David Archer s article on CO2 lifetime in the archives In any event the main thrust of Julianne s point which is that CO2 stays around for a long time but aerosols disappear fast is even more valid Since sulfate pollution and other things that go with dirty coal have a lot of adverse environmental consequences one needs to get rid of this just means one has to work even harder at reducing CO2 raypierre 23 Ryan Sullivan says 21 Feb 2007 at 8 50 PM 18 s comment reminded me of another point that is often lost when discussing the climate effects of aerosols The numbers given by the IPCC are GLOBAL averaged forcings Aerosols due to their short lifetimes are not everly dispersed throughout the atmosphere the way greenhouse gases are with the main exception being ozone The aerosol burden in one region might be quite positive due to high soot loadings as a simple example while in another it might be strongly negative due to high ammonium nitrate and organic carbon loadings from agricultural areas for example Thus the REGIONAL climate impacts of aerosols really need to be considered particularily their effects on precipitation It is too simplistic to think that the negative and quite uncertain forcing of aerosols cancels out most of the positive forcings of GHG Though it is easy to see how this misconception arises 24 S Molnar says 21 Feb 2007 at 9 20 PM Re 22 Somewhat closer to home we have this article which gives a mean lifetime of about 30 000 years for a CO2 molecule with the warning that this is a bit misleading due to the nonlinearity or perhaps I should say the non logarithmic linearity of the decay process It would be nice if we could agree on a metric for CO2 atmospheric lifespan to avoid confusion but I m too confused to propose a good one 25 joel says 21 Feb 2007 at 9 30 PM Remember also the warming caused by increased CO2 has a time lag What is the lag time 26 J Althauser says 21 Feb 2007 at 9 52 PM Re 22 This question has been addressed in an earlier post Water vapor feedback or forcing In the green comments to comment 85 Here is an engineer s view of the problem Residence time of atmospheric CO2 Bottom line CO2 residence times are much longer than 20 years Hope this helps and the links work 27 S Molnar says 21 Feb 2007 at 10 13 PM Re 26 and my own 24 Thanks for the link to Professor Lam s paper I am happy to accept his metric which gives an answer for practical purposes of about 400 years which is consistent with the rule of thumb given in the RC post I linked 28 Craig Allen says 21 Feb 2007 at 10 25 PM So how fast is the science on this advancing How important is this level of scientific understanding to the accuracy of the climate models And how much does each of those LOSU values contribute to the uncertainties in the IPCC warming estimates 29 Marco Parigi says 21 Feb 2007 at 10 43 PM My question is this Doesn t the uncertainty in the aerosol forcing imply equivalent uncertainty in the other anthropogenic forcings Since the overall increase in ghg related emissions is highly correlated if looked at averaged over the whole 200 years since industrialisation error or uncertainty in one would imply more uncertainty in the balance between forcings but less in the overall forcing than you ve shown I thought the overall forcing would have been calculated and cross checked against the measured overall temperature differential I imagined this to be quite accurate On the other hand when CO2 concentrations are increasing and aerosols are decreasing say due to the collapse of dirty eastern bloc industries it would be hard to tease out which was causing observed increases in temperature 30 Richard LaRosa says 21 Feb 2007 at 11 29 PM In reply to Marcus L 19 this article compares CO2 and aerosol forcing and examines the incremental change in forcing due to incremental changes in CO2 and aerosol concentrations It is important to note that a certain percentage change in CO2 produces a smaller percentage change in forcing due to nonlinearity I wonder if the climate forcing of a given aerosol whatever this may mean since aerosol concentrations are regional as pointed out in 23 by Ryan Sullivan is linearly related to its local concentration Also CO2 absorption is due to molecular resonance and is narrow band Aerosol scattering is described I think by geometrical optics and is broad band compared to CO2 Radiation to space at the CO2 resonant frequency takes place from a much higher altitude than the reflection of short wave sunlight or thermal equilibrium long wave IR radiation from an aerosol While trying to write an intelligent comment I realize how complicated this stuff is Enough already 31 raypierre says 21 Feb 2007 at 11 34 PM The uncertainty in aerosol forcing looks unsettling but this is a good example of the case where one needs to ask What are the consequences of this uncertainty for our predictions of future climate One way that the uncertainty affects the future is through the warming due to the decline in aerosols if we move to cleaner burning technologies If the present forcing is large the warming due to aerosol decline willl be larger and conversely The uncertainties in aerosol forcing also have some consequences for deciding which models have the best climate sensitivity though the precise implications of that are a bit harder to see One thing to keep in mind is that if CO2 continues to increase the CO2 increasingly overwhelms the aerosol forcing so aerosol uncertainty may play less role in the future than in the past century A further thing to notice is that as one commenter mentioned the aerosols are not uniformly distributed there s considerable regional variation That means that a climate with a lot of CO2 warming partially offset in the global average by a lot of regional aerosol cooling is still a very different climate than one with no anthropogenic aerosols and less CO2 It s still as Hansen says a different planet we ll be living on I d be interested in hearing more discussion from the aerosol experts here about what it would imply for the aerosol forcing to be on the low end of the range vs what it would imply for the aerosol forcing to be on the high end of the range Keep in mind also that while the article chose to compare just CO2 radiative forcing with aerosols there are other anthropogenic greenhouse gases You could just as well take the sum of radiative forcing from the lesser greenhouse gases CH4 N2O halocarbons and ozone which amount to about 1 2 W m 2 and net them against roughly 1 2 W m 2 of aerosol cooling Put that way you d say the midrange estimate of aerosol forcing cancels out the radiative forcing from the lesser greenhouse gases leaving us with the full effect of CO2 as if the complications weren t there Or Jim Hansen for some reason likes or liked to say that the aerosols canceled out most of the CO2 radiative forcing leaving us to see a little of CO2 plus a lot from the other greenhouse gases That s no more nor less valid but it did open up his paper to a lot of misinterpretations by the media which then got the message that Methane s the problem not CO2 The fact is that for the greenhouse gases radiative forcing is radiative forcing and it doesn t make much sense to break it apart when comparing to aerosols It makes sense to break it apart mainly because the different gases have different atmospheric lifetimes 32 Philippe Chantreau says 21 Feb 2007 at 11 43 PM I have a question not directly related to the topic of aerosols but to a point that someone brought up higher in the discussion Chevron and other big combustion players maintain blogs on which there are seemingly inexhaustible supplies of skeptics who can sound technical enough to be convincing for most of the general public One of their favorite battle horses is the absorbtion spectrum of CO2 which they maintan is too narrow to account for the forcing attributed to the gas Any help on that Response See the discussion of the spectrum of CO2 absorption in Dave Archer s global warming text and play with the online models For a more technical discussion take a look at my climate textbook draft online chapter 4 see geosci uchicago edu rtp1 or Goody and Yung We don t have an article on this because only the least informed skeptics are using the argument anymore and nobody of any consequence believes it Perhaps we ought to have something like that in the wiki for general education raypierre 33 BarbieDoll Moment says 22 Feb 2007 at 12 23 AM RE 22 An estimate of anthropogenic CO2 inventory from decadal changes in oceanic carbon content Proceedings of the National Academy of Sciences 2007 doi 10 1073 pnas 0606574104 http dx doi org 10 1073 pnas 0606574104 Approximately half of the anthropogenic carbon released to the atmosphere from fossil fuel burning is stored in the ocean although distribution and regional fluxes of the ocean sink are debated Estimates of anthropogenic carbon Cant in the oceans remain prone to error arising from i a need to estimate preindustrial reference concentrations of carbon for different oceanic regions and ii differing behavior of transient ocean tracers used to infer Cant In contrast to prior approaches the results are independent of tracer data but are shown to be qualitatively and quantitatively consistent with tracer derived estimates The approach reveals more Cant in the deep ocean than prior studies with possible implications for future carbon uptake and deep ocean carbonate dissolution Our results suggest that this approachs applied on the unprecedented global data archive provides a means of estimating the Cant for large parts of the world s ocean Distribution and inventory of anthropogenic CO in the Southern Ocean Comparison of three data based methods Journal of Geophysical Research 110 c9 09 2 2005 doi 10 1029 2004jc002571 http dx doi org 10 1029 2004jc002571 North of 50Â S distribution and inventories of Cant are coherent with previous data based and model estimates but we found larger storage of Cant south of 50Â S as compared to the midlatitude region In that our results disagree with most previous estimates and suggest that the global inventory of anthropogenic CO2 in the Southern Ocean could be much larger than what is currently believed Response to Comment on The Ocean Sink for Anthropogenic CO2 Science 308 5729 1743d 2005 doi 10 1126 science 1109949 http dx doi org 10 1126 science 1109949 The correct determination of the magnitude and uncertainty of the oceanic uptake of anthropogenic CO2 and of the climate change feedbacks is of prime relevance to constrain the net balance of the terrestrial biosphere over the past 200 years Climate carbon cycle feedbacks under stabilization uncertainty and observational constraints Tellus B 58 5 603 2006 doi 10 1111 j 1600 0889 2006 00215 x http dx doi org 10 1111 j 1600 0889 2006 00215 x However the observational record proves to be insufficient to tightly constrain carbon cycle processes or future feedback strength with implications for climate carbon cycle model evaluation The Oceanic Sink for Anthropogenic CO2 Science 305 5682 367 2004 doi 10 1126 science 1097403 http dx doi org 10 1126 science 1097403 The current fraction of total anthropogenic CO2 emissions stored in the ocean appears to be about one third of the long term potential 34 Marco Parigi says 22 Feb 2007 at 12 57 AM As a counter assertion to some denialists assertion of solar forcing being way bigger than the graph shows I d like to assert that the forcings from CH4 N20 and Halocarbons are double what the graphs indicate and that the forcing from CO2 is less than half that I have said before that this would imply a big policy shift Neither the cold case evidence or the CSI evidence seems to be able to disprove this assertion Am I missing some critical scientific experiment here that would change my skeptical mind I m not sure of the author of that graph but what makes them so confident about their CO2 vs CH4 forcings being accurate to within 20 of their ranges or so Response The forcings by the greenhouse gases have little uncertainty because their concentrations are accurately measured in the atmosphere and their infrared absorption properties are very accurately measured in the laboratory The two are put together using highly accurate numerical methods that have little error The small uncertainty is primarily because the radiative forcing depends on temperature profiles well observed water vapor profiles somewhat less well observed and cloud profiles with additional uncertainties The water vapor and clouds come in because you get little additional radiative forcing from greenhouse gas increases below a thick cloud Similarly water vapor competes somewhat with absorption due to the other greenhouse gases There is no plausible ways these uncertainties could be stretched to accomodate the scenario you are proposing raypierre 35 James Annan says 22 Feb 2007 at 12 57 AM Raypierre 32 If you want to see one aerosol expert s view look here I happen to think it s greatly exaggerated

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  • Ozone impacts on climate change « RealClimate
    iron to bring the deadand dying seas to life is that it is reversible to very great extent since simply ceasing to give iron causes the sea to revert to its previous dead state it allows a dynamic monitored solution to getting the CO2 back into biomass where we know the earth can cope with it Strangely enough we would all live healthier lives WITHOUT the petrol driven car so one could hope that the oil price becomes realistic even more quickly than it is so that this vast hazard to short term and long term health of all of us dies out quickly sadly few people realise that every car on teh road could be responsible for seven deaths in the future according to one model I developed assuming as many do that tomorrow will e much like today really is an imprudent way to live which could very conceivably not only cost much life on earth its existence but spell the chnage of civilisation for man back to just smallis local communities living much in isolation from each other much like in the past not from choice but from necessity and the earth then supports far fewer people than today It does not seem worth taking the very describable risk of this happening for sake of the inaction we see today but equally those trying to make perfect models of how tings work will also run out of time and cheap oil todo their research we are complacent today in our industry and life support but it is very largely fully dependent on cheap oil which is already showing that it will never be cheap again but will keep rising in price This site and forum does good work indeed in spreading the truth to combt the endless propaganda of dinosaurs who believe the growth paradigm still desp ite the evidence already that it is a short sighted and inefficient principle thsu incompatible with sustainable life of men and other animals and plants but the dynamic question is can it spread the word fast enough and are minds open enough to change to learn and act on the truth before we have killed our seas and have no way to a sustaiable life left 15 Bird Thompson says 28 Jul 2007 at 10 11 AM Animal farming accounts for 18 of GHGs more than transportation UN Food Agriculture Organization One thing we can all do is eat less animal based meals Eating vegan vs eating animals in terms of the impact on climate change is like riding a bike vs driving a Hummer The resistance to changing diet is huge Sierra Club Al Gore etc don t even mention the vegan option in combating global warming We must expand our imagination to see the cause effect relationship between our life habits the dying planet The mega corporations that take grain water to feed to animals don t want you to know how much methane they produce or how it affects the climate They want you to eat more burgers drink more milk We are in an emergency situation We must act on all levels to reduce GHGs including changing our personal habits cultural traditions of eating 16 tamino says 28 Jul 2007 at 10 48 AM Relying far less on animal husbandry i e eating less meat doesn t require going all the way to vegan It s possible to drastically reduce one s intake of animal products without quitting entirely Eating meat only a few times a week emphasizing seafood over beef expending the effort to secure meat products that are much more local than intercontinental all will reduce the energy requirements and therefore greenhouse gas emission involved in animal husbandry And while a vegan diet brings undeniable health benefits strict adherence to a strictly vegan diet over the long term also carries certain health risks Moderation rather than extremism is likely to be more effective and vastly likely to win more converts 17 Nick Gotts says 28 Jul 2007 at 11 09 AM Re 15 The resistance to changing diet is huge Yes indeed it s interesting how even on this site there s what appears to be a defensive resort to levity 7 9 or proposing measures which would have much less effect 8 when this is suggested I m a lacto ovo vegetarian with occasional fish eating I ve reduced the animal derived content of my diet considerably over the past few years but I hereby promise to shift further in a vegan direction from now on Methane production is not the only issue large amounts of tropical forest have been and are being cleared to ranch cattle and to grow soya to feed them in intensive systems elsewhere 18 See owe to Rich says 28 Jul 2007 at 12 00 PM This is just my 2nd posting on climate matters and as I ve only been studying this for 2 months part time and am not a climate scientist but merely a Ph D in mathematical statistics aficionados can take my views with a pinch of salt if they wish Certainly I am extremely impressed and somewhat humbled by the wealth of knowledge both here and on ClimateAudit org Even so I am hoping that a posting from an outsider may have some value in summarizing the central issues Accordingly I am going to ask 4 questions here and then discuss the relevance to these of 3 recent papers I have to say that I am certainly in two minds on the issue of the extent of Anthropogenic Global Warming AGW I do worry that in central England clear winter skies no longer guarantee frost the way they used to do but from studying climate data I also find it difficult to believe in the IPCC s central projection of a 3C increase during this century In other words I am not yet convinced that the CO2 effect will be as large as claimed The crucial questions modulo changes to my chosen time intervals seem to be along the lines of Q1 what degree of global warming actually occurred between 1970 and 2000 Q2 how do we apportion this between CO2 the Sun and other causes and therefore how much is a doubling of CO2 worth Q3 how much warming will occur over the next 100 years Q4 how good or bad will this warming be for the world These questions are fairly simple to state but furiously difficult to answer apparently I am not going to attempt that here but merely discuss them For Q1 some would argue that a different interval should be studied but the CO2 brigade to distinguish from the solar brigade have a valid question as to why it warmed significantly in that period about 0 4C according to the hadcrut3 figures But as an outsider I find it deeply disappointing that the physical basis for the accuracy and fairness of the quoted data is in some doubt for some of the terrestrial stations Nevertheless I do not find it necessary to invoke a conspiracy to account for this I have always believed in the cock up version of history sometimes with the occasional conspiracy to cover up the cock up I believe that it is important to establish a non controversial set of data for example from rural sites with thermometers placed a good distance from air conditioners etc Q2 is the biggy insofar as it impacts Q3 which is where the politics come into play In the CO2 brigade it may be possible to find claims as high as 125 for the CO2 effect i e the sun weakened in that time so CO2 warming covered the 0 4C plus more for solar loss In the solar brigade it might be put as low as 0 but some of this brigade allow it to be in the region of 25 i e 0 1C out of the 0 4C The modellers rate the CO2 effect at a very high level but it is quite possible that God is playing a cruel trick on them making the CO2 models fit well in this period but really using some different effect for most of the change I shall discuss this more below For Q3 even if we allow for 0 0133 0 4 30 degrees per year in 1970 2000 I don t see how the IPCC can turn that into 0 03 degrees per year for their central 3 0C per century or is it 92 years But I m not an expert so perhaps it comes from bits of modelling I cannot be expected to understand The other thing about the 3 0C though is that it ignores solar effects I have seen no refutation of the association of the depths of the Little Ice Age with the Maunder Minimum of solar activity further it appears that sunspot effects are greater than is the total solar irradiance TSI Now if the Sun had been in an average state since 1960 or so it would be reasonable for the IPCC to argue that over the next 100 years it might on the whole remain average But Solanki et al have shown that the Sun has been in an unusually active state and as with the housing market one might therefore be expecting a fall before 100 years are out Regarding Q4 I have seen many and many more arguments on both sides Personally I am quite happy for England to be a little warmer and I am happy if more CO2 helps all those beautiful plants to grow But my house currently 27 7 07 has no tap water and the stream through our garden rose 5 feet to a torrent coming within a couple of inches of our floorboards Was that caused by global warming The Met Office tells me that it probably was On the other hand the last time the River Severn got almost as near to Tewkesbury Abbey in 1947 was at the onset of a period of global cooling and there were several famous floods in the 50 s too And the time when it got really high in 1760 when the canon of the Abbey was rowing along the aisle rather than merely paddling was well I don t really know but it wasn t during CO2 induced global warming Warming followed by cooling globally is arguably the best recipe for heavy rains just like with a cold front locally you have warm moist air precipitated by cold air Moving on to the 3 papers talks I want to start with Green and Armstrong Here in RealClimate they have been criticized for translating their forecasting criteria formulated in the econometric world to the climatic world as if that s a bit of a dirty trick As an interested outsider I think that forecasting is forecasting there are data models parameters and errors between the data and the models I don t care if the models come from physics or economics I just want a sound forecast I am amazed that there could be so many forecasting principles as they claim and I wonder how many forecasters in any sphere of life could pass a test of so much red tape Nevertheless if real climatologists want to convince me then they need to answer the searching questions posed by that paper of Green and Armstrong as others have said they are at liberty to give their own versions of scores if they can demonstrate that G and A s ignorance of climatology led to unreasonable assessments The second paper is Lockwood and Frohlich I found this really interesting reading and it certainly notched my personal CO2 brigadometer up a bit for a few days But then I thought if very little of the 11 22 year solar signal comes through in global temperatures what effects there are must be smeared over longer time spans So if the sun was extra active from say 1910 to 1985 then with the smearing time lag one would expect global temperatures to rise beyond 1985 flatten off and then fall There s a lot of argument over whether 2001 2007 data represents a flattening but that s the way it looks to me I would be tempted to argue that this British summer represents a cooling but that would be parochial since it s hot in Eastern Europe and hadcrut3 is still holding up reasonably The third item is slides from David Archibald s talk in Melbourne in June 2007 I had never seen this relationship between solar cycle length and temperature before that an early late onset of a solar cycle is correlated with an increase decrease in global temperatures There are things I don t understand about this especially the time lag so I am trying to follow up some of the references to understand more Possibly Archibald is over egging it especially since there are wide variations in the predictions for the sunspot count in Cycle 24 but a real downturn in the Sun would be a wonderful test between the two brigades Lockwood and Frohlich say the Sun turned down from 1985 onwards but by the measure of cycle length Cycle 23 started earlier than average in 1996 so it can only be after Cycle 24 starts late probably around 12 0 12 5 years compared with a mean 10 6 that there will be a concensus that the Sun is on the way down Then if the temperatures do not dip by as much as Archibald predicts for given lateness of cycle or even increase we will be able to get a better estimate of how much effect a doubling of CO2 really has And then we shall know whether they are right those correspondents on this site who share thoughts of the ilk Lockwood and Frohlich have banged in the last nail in the coffin of the solar theory of global warming 19 tamino says 28 Jul 2007 at 1 49 PM Re 18 See owe to Rich I too am a statistician my specialty is time series analysis and I confess that certain aspects of your post puzzle me There s too much covered to ask all my questions in a single response without begin excessively long so I ll start at the beginning You say Q1 what degree of global warming actually occurred between 1970 and 2000 about 0 4C according to the hadcrut3 figures even if we allow for 0 0133 0 4 30 degrees per year in 1970 2000 How did you arrive at these figures Straightforward linear regression of HadCRUT3 data from 1970 to 2000 gives a slope of 0 016 deg C yr not 0 0133 and would imply an overall warming for the three decades of 0 048 deg C not 0 4 For Q3 even if we allow for 0 0133 0 4 30 degrees per year in 1970 2000 I don t see how the IPCC can turn that into 0 03 degrees per year for their central 3 0C per century or is it 92 years But I m not an expert so perhaps it comes from bits of modelling I cannot be expected to understand Your estimate of 0 0133 deg C yr as the present warming rate or even the rate from 1970 to 2000 is considerably in error Furthermore since 1970 global warming has shown statistically significant acceleration The overall rate over the last 30 years is more like 0 018 deg C yr and the rate since the year 2000 is 0 020 deg C yr according to HadCRUT3 and a whopping 0 031 deg C yr according to GISS As you say you re not expected to know the details of the physics or the models but as a statistician I do expect you to know these details So again I m sincerely curious how did you arrive at your figures 20 Lynn Vincentnathan says 28 Jul 2007 at 3 41 PM Good post It s along the lines I ve been thinking from the beginning we need a holistic approach I d been mainly telling people that measures to reduce GHGs also reduce lots of other pollution which cause harm death and have other positive non environmental benefits like 1 saving money without lower living standards or economic productivity up to perhaps a 3 4 reduction of GHGs or more 2 improving health spirits and crime and taxes for road building repair by off setting some driving with walking cycling 3 reduce wars over oil 4 etc But even the internal issue of GHGs climate change are extremely complex I know science trudges along slowly and gets to the complex picture only after dealing with the more simple pictures But we can conceive that our world is indeed exceedinly complex so much so that as anthropologist Roy Rappaport suggested we need to hold the environment in awe and respect Because we don t know it all perhaps never will and we should be careful in our dealings with it 21 Michael says 28 Jul 2007 at 4 30 PM Re 18 It is not obvious that global warming will be beneficial for plant life on earth For example see http www newswithviews com Peterson rosalind4 htm for an indication of how trees are dying The critical condition of the amazon is well documented In terms of your Q4 the situation we face is an emergency It is a bit like driving a car on motorway at 70 mph and seeing a pile up in a front at a distance of 96 metres and knowing that your stopping distance is about 96 metres One might be tempted to slam on the brakes 22 Paul says 28 Jul 2007 at 4 41 PM I recently read something on the heretofore unperceived threat of water dimers I am wondering if Gavin or anyone would care to comment on this issue 23 Steve Bloom says 28 Jul 2007 at 5 45 PM Re s 18 19 Uses of phrases such as the wealth of knowledge both here and on ClimateAudit org and CO2 brigade give away the game IMHO A PhD in mathematics honestly approaching the climate change issue for the first time would know better than to engage in the sort of cherry picking of evidence and out and out asyllogisms evidenced throughout 18 Tamino s pointing out of some pretty basic stats errors are the icing on the cake 24 Chuck Booth says 28 Jul 2007 at 8 52 PM Re 18 a Ph D in mathematical statistics I don t mean to be flippant but isn t mathematical statistics redundant Is there any kind of statistics that isn t mathematical 25 Timothy Chase says 28 Jul 2007 at 9 11 PM Paul 22 wrote I recently read something on the heretofore unperceived threat of water dimers I am wondering if Gavin or anyone would care to comment on this issue I hope that someone will comment on their specific application to greenhouse gas theory Doing just a little research I found that these weak hydrogen couplings between water molecules isn t as well understood as we might like and that part of the problem involves the interaction of the light hydrogen atoms with zero point energy that is the virtual particle buzz thats always there even when space is empty I suppose the uncertainty involved in its interaction with the zero point might help to explain why is able to amplify the chirality of the weak force at roughly ten times the magnitude that was predicted and perhaps why we are able to freeze at room temperature with an electrical field at one one thousand the strength that had been predicted Crazy stuff Going off of what Eli wrote earlier this afternoon A Saturated Gassy Argument comment 306 it would appear that they result in additional dimensions in the phase space description of water as it exists in the transitory dimer state And it appears to be a bit of a black hole in our knowledge for the time being but would apparently operate in the far IR spectrum At first glance a 2004 paper didn t look that promising but I am no expert However doing a little more digging I ran across something which is clearly related and from the perspective of theoretical understanding looks quite promising which I had brought up previously although I didn t have the paper at the time Here is the write up for it Computing water s quantum properties Despite water s centrality to life its quantum properties are still not fully understood Alexander Donchev et al have developed a mathematical model that accurately describes water s properties from first principles The model may be useful for understanding water s properties in a pure state and in biomolecular systems Donchev et al applied a quantum mechanical polarizable force field model which they had developed for studying organic systems to the simulation of pure water The model accurately calculated water s thermodynamic and structural properties including its unique density changes near 0 C The model which is based on quantum mechanical calculations for systems of small molecules and their dimers showed as good or better agreement with the measured properties of liquid water than previous computer models devised strictly to fit those properties The authors say that further refinement of the equations and parameters in their model should bring it even closer to reproducing water s properties The model may also be useful for understanding the interactions between water and organic molecules such as proteins In This Issue Proc Natl Acad Sci U S A 2006 June 6 103 23 8573 8574 http www pubmedcentral nih gov articlerender fcgi artid 1482620 The paper is free access to any and all on the other side If you are interested in the other topics you might check out the following 2006 technical P Violation Manifested at the Molecular Level A Simple Means for an Absolute Definition of Left vs Right Avshalom C Elitzur Meir Shinitzky arXiv physics 0601010 v1 3 Jan 2006 http arxiv org PS cache physics pdf 0601 0601010 pdf Number 742 1 August 19 2005 by Phil Schewe and Ben Stein Room Temperature Ice in Electric Fields http www aip org pnu 2005 split 742 1 html Oh and an interesting implication of parity violation 2005 technical Subtle differences in structural transitions between poly L and poly D amino acids of equal length in water Yosef Scolnik et al Received 3rd October 2005 Accepted 21st November 2005 First published as an Advance Article on the web 5th December 2005 DOI 10 1039 b513974k http www rsc org delivery ArticleLinking DisplayArticleForFree cfm doi b513974k JournalCode CP 26 Timothy Chase says 29 Jul 2007 at 12 51 AM PS post 25 It should be obvious but I was still tuning into KW TC when I started writing the post A little of that all too common static Or perhaps it has something to do with the structured water in one of my brain cells or within the hydrophilic catalytic core of some ribozyme Who knows The second sentence should read Doing just a little research I found that the weak hydrogen couplings between water molecules aren t as well understood as we might like and that part of the problem involves the interaction of the light hydrogen atoms with zero point energy that is the virtual particle buzz thats always there even when space is empty 27 ChrisC says 29 Jul 2007 at 1 35 AM Re 18 The third item is slides from David Archibald s talk in Melbourne in June 2007 I had never seen this relationship between solar cycle length and temperature before Archibald s paper published in Energy and and Environment was called by one commentator The worst climate science paper ever of all time anywhere see http n3xus6 blogspot com 2007 02 dd html and if you had taken the time to read it as a PhD you should have seen several of the most glaring statistical errors it is possible to make Here are a few of the howlers Instead of using the world wide temperature from say GISS or Hadley he choses a total of five stations Yes five all in the within several hundred kilometers from each other in the South Eastern United States The stations chosen buck the trend of increasing temperatures in the later half of the twentieth century The stations chosen indicate lower temperatures in the later part of the twentieth century which is not reflected in the vast majority of stations worldwide Since so few met stations were chosen one has to wonder if they were chosen so that they would fit Archibald s argument In order to predict the temperature response to the changing solar cycle length he uses a single temperature station De Bilt in the Netherlands Not even 5 stations A single station He then decides that the correlation between De Bilt and the solar cycle length is good but fails to mention the R 2 value because the correlation is poor He also uses cherry picks data from the complete set of temperature records from the station This is misleading and wrong When the full data set is used the R 2 value for the correlation is only 0 0177 Archibald then predicts a reduction in temperature of 1 5C over the next solar cycle He claims he can do this due to correlation with cycle amplitude but then presents a graph of solar cycle length to illustrate the correlation He offers no explaination He also has used very strange predictions of the solar cycle In short this paper is weak as starbucks coffee and citing it is unlikely to earn you any credibility As one who has studied stats you should probably be able to pick these errors from the paper without difficulty 28 Geoff Russell says 29 Jul 2007 at 1 54 AM Re 16 If you are in the US then you can t increase fish consumption unless some other country volunteers to decrease its consumption because the US is a net fish importer by about 2 4 billion pounds http www st nmfs gov st1 fus fus06 fus 2006 pdf Fish farming as currently practiced usually with carnivorous fish is a net consumer of fish not a producer Re 6 The list of anthropogenic methane sources omitted the biggest source livestock Researchers at Sydney University in conjunction with the Australian Conservation Foundation have recently put a very good eco calculator on line Pretend you live in Australia and see what influences your personal carbon footprint http www acfonline org au custom atlas index html For most people on the planet except the sort of people who perform at Live Earth what they eat is the principle determinant of their own personal climate forcing footprint This is usually obscured because most studies simply don t follow the full production chain Even the much publicised Japanese Life Cycle Analysis looking at the ghg emission intensity of beef stopped at the farm gate no refridgeration no abattoir costs etc etc It still found the emissions cost of a kg of beef to be about double that of aluminium Lastly back to 16 No you don t need to be a vegan to lower you emissions substantially just like I am not car free but I use a bicycle for most of my transport and my car is small and old Lastly given that vegetarians vegans have lower rates of most diseases than meat eaters then whatever these risks are they are smaller than the risks associated with meat like heart disease colorectal cancer the destruction of the amazon etc 29 rojo says 29 Jul 2007 at 8 46 AM re 21 your link is a giggle Damn those jet contrails Loved the references and 5 year old tree photos You were joking Michael 30 J C H says 29 Jul 2007 at 10 17 AM I ll go with the vegan diet the day the vegans agree to shoot the 100 million cattle that call the good old USA home And say goodbye to wool And having human beings live longer does what to greenhouse gas production And how many ruminants do countries that eat little meat have Not eating them is enough That really does nothing much at all All the grain will still be needed for ethanol so that won t stop Additional fossil fuels will be burned to add the mountains of vegetables that will be needed to replace meat calories The net benefit is unlikely to be as advertised How many greenhouse gases will all these long lived people be producing when they re vegetating in nursing homes until they re 110 You have to kill ruminants them to stop them from belching 31 Timothy Chase says 29 Jul 2007 at 10 29 AM Gavin Improved Modeling of Tropics Temperatures and IR absorption by clouds Laboratory measurements of water vapor absorption using cavity ring down spectroscopy revealed a broad absorption at 405nm with a quadratic dependence on water monomer concentration a similar absorption with a linear component at 532 nm and only linear absorption at 570nm in the vicinity of water monomer peaks The resulting estimation of 15 30Wm 2 could cause a difference of 4 C in the calculated average surface temperature of the earth Carlon 1979 Arking 1996 1999 Observations of this anomalous absorption found that the discrepancy was measurable in tropical regions and near clouds Hill and Jones 2000 but were complicated by the presence of scattering by particulates Potential sources of the additional absorption include absorptions due to water dimer and water far wing continuum absorption Water dimer has been calculated to absorb 3 6Wm 1 of solar radiation from calculations that used an outdated model for Helium clusters Tso et al 5 1998 and were then recalculated to be less Vaida 2001 Daniel et al 2001 Water dimer absorption of visible light J Hargrove Atmos Chem Phys Discuss 7 11123 11140 2007 http www atmos chem phys discuss net 7 11123 2007 acpd 7 11123 2007 print pdf FrameEngine false Exciting stuff Just a guess but this might help with modeling of the Indian Monsoon and the western edge of the Tibetean Plateau which has been a bit of a problem for all models so far 32 James says 29 Jul 2007 at 11 57 AM Re 30 You have to kill ruminants them to stop them from belching Not that I m buying into the vegetarianism stops climate change argument but you don t have to kill them all unless you want an immediate effect You just stop letting them breed and in a decade or two you ll find the numbers greatly reduced Of course you could short circuit the vegetarian phase and just apply the same logic to H sapiens 33 wildlifer says 29 Jul 2007 at 12 32 PM Just another reason for the denialists claims we should eradicate termites rather than reduce emmissions But there s an even more ominous hurdle from AnnCoulter sychophant Mr Magoo Location California al Gore and his tree kissing minions insult God with their global warming claptrap They think the Almighty was stupid for putting sloppy SUV driving humans on this planet when in fact He designed it and the universe to withstand just about anything humans could do Mr Magoo was blind wasn t he 34 Lawrence Brown says 29 Jul 2007 at 2 16 PM Re 33 wildlifer s comment The Ann Coulters of this world have one main interest to draw attention to themselves regardless of who might get hurt by the outrageous comments It s good for her book sales I don t know of anyone who has less credentials to call global warming claptrap Plant species are migrating northward in the northern hemisphere as are animal species Does the cockroach have more of sense about global climate change than the Cockburn and Coulter I m afraid so The subject of this latest article prompted me to read up on the strength of methane gas and I found that the enhanced greenhouse effect of a molecule of methane is about 8 times that of a molecule of CO2 Global Warming by John Houghton p 42 but when an index called Global Warming Potential GWP is used which measures the instant release of 1 kg of a gas to that of the release of 1 kg of carbon dioxide then methane has a GWP of 23 since the atomic weight of methane is 16 44 or 36 of that of CO2 same source as above Table 10 2 This is for a time horizon of 100 years GWPs have to be used with caution because GWPs for different time horizons are very different 35 Timothy Chase says 29 Jul 2007 at 2 36 PM Paul 22 wrote I recently read something on the heretofore unperceived threat of water dimers I am wondering if Gavin or anyone would care to comment on this issue Paul I believe this is what you were refering to This transition peaks at 409 5 nm could be attributed to 8th overtone of water dimer and the 532nm absorption to the 6th overtone It is 10 possible that some lower overtones previously searched for are less enhanced These absorptions could increase water vapor feed back calculations leading to higher global temperature projections with currently projected greenhouse gas levels or greater cooling from greenhouse gas reductions Water dimer absorption of visible light J Hargrove Atmos Chem Phys Discuss 7 11123 11140 2007 http www atmos chem phys discuss net 7 11123 2007 acpd 7 11123 2007 print pdf FrameEngine false It is from the article I mentioned in 31 The good news is that this is something climatologists can use to objectively improve the predictive power of climate models assuming its real And as Hansen has pointed out they tend not to feel comfortable in suggesting the existence of vague threats but only in stating that there exist certain well defined threats which they can identify If it is real then it will be great that we have identified it sooner rather than later It wouldn t surprise me if we have made another one of those big discoveries regarding water As I ve said its crazy stuff Response Don t get too excited The dimer idea has come up repeatedly in the past as a solution to the anomalous absorption issue that was all the rage a decade ago Since then most of the anomaly has disappeared mainly due to improved understanding of aerosol effects but the dimer idea persists A brief conversation with our radiation people left me with the impression that the only substantial effects can be seen in the microwave region which is irrelevant for climate purposes This latest paper seems interesting but there are a couple of howlers in the intro and conclusions confusion of a short wave absorption effect with the long wave water vapour feedback SW effects do not contribute to the greenhouse effect and so I d wait for the reviews to come in before assessing it s worth The biggest problem is that existing line by line models do a really good job of explaining what is seen either at the ground or at the surface and so there isn t any huge discrepancy that requires exotic new physics to explain Having said that this isn t my field and I m open to being corrected by people who know better gavin 36 Timothy Chase says 29 Jul 2007 at 4 08 PM gavin inset to 35 wrote Don t get too excited The dimer idea has come

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  • Perspectives from China « RealClimate
    Oh right Not enough advertisers to sponsor it 13 Gareth says 26 Sep 2007 at 5 45 PM I ve also recently spent time in China though my reasons were mycological rather than paleoceanographical Those little electric scooters are obviously a good thing but also a danger to pedestrians you can t hear them coming And I was very impressed by the number of solar water heaters to be seen on the tops of apartment buildings even yak herders turned matsutake harvesters homes I was actually quite impressed by the availability of broadband internet in hotels Most had broadband connections in every room even if they weren t always connected up But the Asian brown haze is an amazing and terrible thing Even in the largely rural province I visited Yunnan there was significant eye watering pollution around major cities Cleaning that up is going to be no small task 14 Raplh Smythe says 26 Sep 2007 at 6 03 PM Hank I didn t say anything about sediment Are you talking about Lake Baikal My point was that the discussions should go towards influencing policy makers and or the general public and not quibbling about minutia with people that clearly think differently about the issues It s pointless 15 SteveSadlov says 26 Sep 2007 at 6 05 PM I ve been dealing with the PRC for over a decade There is something in the Chinese communist mentality which most Westerners fail to grasp The value of human life the human spirit is considered much lower than it is in Western cultures and isolated examples elsewhere in the world In fact there is a certain fatalism about physical life in the here and now This leads to an overall destructive mentality Certainly the West had its moments in the past But back in those days decades ago when we were the primary belchers of unmitigated filth our population was much much lower There were large spaces between our cities and the impacted areas were actually pretty small There is no precedent for what is going on in China now 16 joel says 26 Sep 2007 at 6 13 PM If we don t China will eventually do it without us and it will be we who will end up buying those technologies from them Our choice As you must know China is on a coal power plant building frenzy about 1 per week is opened I have read using the most primitive technology available and avoiding more advanced technology from Europe or the USA China is and seems intent on being the lowest cost producer in the world So get used to the brown haze 17 Hank Roberts says 26 Sep 2007 at 6 53 PM Raplh Gavin started the thread talking about the need for more discussion among the scientists who are working in paleo oceanography the overwhelming focus on downcore records and the need for them to talk We agree I guess that we nonscientists should sit back and hope Gavin gets that conversation going Gavin did any discussion of the content of Ward s book Under a Green Sky come up at your meeting 18 SteveSadlov says 26 Sep 2007 at 7 10 PM RE 10 The problem is China is now addicted to coal Most current installations burn high sulfur soft coal There is very little use of high quality low sulfur hard anthracite Due to the lack of air pollution control laws any meaningful air basin authoritie systemic monitoring etc both the state i e power generation and industry have exploited the situation As you ride the ferry up into the Pearl River Delta there are stacks upon stacks to the horizon and beyond I have never seen any thing like this elsewhere not in the old US rust belt not in the UK midlands not in the Ruhr There is now much talk of reducing coal based pollution in the PRC I shall believe it when I see it 19 ray ladbury says 26 Sep 2007 at 7 48 PM Steve Sadlov First I don t think it is fair to say that the Chinese or the communists for that matter for China is hardly communist in any meaningful sense do not value life China s policy on almost everything is driven by two related factors its massive population and its alarm at being so far behind the West and particularly the US technologically The latter represents an external threat to the survival of the Chinese Oligarchy The former represents an internal threat China s economy needs to grow at 8 per year just to keep up with the growth of the workforce and a large cadre of unemployed and likely sexually frustrated given the gender ratios males is not a welcome prospect The Chinese will use whatever means they can to address these threats and if that trashes the environment well those threats will manifest further down the line However the crisis presents a considerable opportunity we can try to facilitate making cleaner technologies available to the Chinese The infrastructure they adopt will penalize or reward us for decades and maybe centuries to come 20 John Norris says 26 Sep 2007 at 8 24 PM re 19 for China is hardly communist Someone better tell them to edit their constitution then the Chinese Communist Party CCP is the ruling political party of the People s Republic of China a position guaranteed by the country s constitution http en wikipedia org wiki Communist Party of China 21 Figen Mekik says 26 Sep 2007 at 8 30 PM I think it is insulting to say that the Chinese or any people for that matter do not value life First that is unknowable and second it serves to alienate and isolate groups of people from others I am sure Sadlov did not intend this but it is easy to interpret it from phrases like Chinese do not value human life as much as westerners do It s not adiret quote I paraphrased a little 22 Karen Kohfeld says 26 Sep 2007 at 9 38 PM Gavin I think you ve highlighted some great points both about the need for data synthesis and also the difficulties in obtaining them There is frequently a tendency to underestimate the effort and resources required to take data from multiple sources and assemble them in a manner so that they are compatible same time scale same units indicators presenting the same environmental parameter Both PMIP and MARGO projects were multi year multi decade in the case of PMIP projects involving many principle investigators It seems to me though that there have been other recent data synthesis successes although perhaps the majority have been centered in terrestrial data rather than the paleoceanographic community I m thinking of the drought data in the midcontinental USA remarkable data compilations of Arctic temperature and vegetation changes for the last few millennia the Holocene and most recently the last interglacial to name a few There are always a few individuals who focus on synthesis but it s refreshing to hear that there is a developing community wide interest amongst paleoceanographers to create benchmark datasets 23 danny bee says 26 Sep 2007 at 9 38 PM Unless a Chinese Gorbachev comes around there soon the entire world will fall victim to China s big bag of lethal tricks It is the most dangerous country in the world and we should all refuse to go to the Olympics there Send a message to China the communists there who do not value life only their own Response Folks this particular discussion is getting way off topic so this will be the last such post we ll allow If you want to discuss the politics take that to some other site Thanks mike 24 ray ladbury says 26 Sep 2007 at 9 42 PM John Norris Try walking out of the Terra Cotta Army Museum and dealing with the hawkers outside or walk through any Chinese market and you will find capitalism at its most raw The communism in China is merely a useful fiction that perpetuates the myth of continuity and stability There is nothing there now that Marx Lennin or even Mao would recognize 25 SteveSadlov says 26 Sep 2007 at 10 11 PM RE 19 So I ll open my kimono a bit here I am quite a mutt in terms of ethnic background Based on matrilineal descent I am Jewish but am also a bit Chinese father s side What I describe is not meant to offend It is meant to bluntly shatter some of the notions that Westerners who can easily fall under the spell of so called oriental mystique may entertain This is especially common I have noticed with many of the Western business people who are currently quite obsessed with China There is an understated brutality that is simply embedded in Chinese culture To get somewhat of a sense of this the Amy Tan books are actually not all that bad believe it or not particularly the sequences dealing with life prior to emigration to the US Amy has clearly been very observant of her own family Chinese friends and has also done her homework Indeed some of the things you ve noted factor into why this is Let me explore the statement about value of human life value of human spirit a bit more Some may commend the fact that Chinese society is less individualistic and more communitarian this predates commun ism by millennea than most Western ones Fair enough But there is also a dark side as with all things involving humans Confucianism combined with millennea of paternalistic authoritarian social organizational priciples have resulted in the issues with value of individuals that I have noted If I were to portray a spectrum with the purest Anglo Saxon English Common Law human rights culture at the left end and the purest Far Eastern top down do as you are told culture at the right end Chinese culture both pre and post Mao would certainly be much closer to the right end and realized 21st century Anglo Saxon ones closer to the left end People who take human rights very seriously would likely render similar analysis I make no deterministic value judgment I simply report what I have learned from real life 26 dhogaza says 26 Sep 2007 at 10 54 PM for China is hardly communist Someone better tell them to edit their constitution then Stalin s Constitution was perhaps the most liberal in regards to person rights and civil rights ever written Yet millions did die in the Gulags the oppression against the Kulaks etc What counts Words written on paper or actions The answer is simple I think 27 Hank Roberts says 26 Sep 2007 at 11 09 PM C mon John the Chinese have communism like the USA have a republic Editing either their or our Constitution would be a distraction from the real work urgently needed eh World to save and all that At the close of the Constitutional Convention in Philadelphia on September 18 1787 a lady asked Dr Franklin directly Well Doctor what have we got a republic or a monarchy A republic if you can keep it responded Franklin http www bartleby com 73 1593 html Gavin how about the scientists in your host country there why were you meeting there specifically Hope to educate the politicians New info not published outside China to discuss 28 Mark A York says 26 Sep 2007 at 11 59 PM Generally the closer life comes to carrying capacity the less value it has and the more perilous life s struggle becomes We still burn coal with the same result air polution CO2 increases and mercury dumped in the seas fed back to us in tuna where it biomagnifies The result is the same no matter who does it 29 Paulina says 27 Sep 2007 at 12 10 AM More science less responding to the trolls Yes please 30 jonathan sawyer says 27 Sep 2007 at 12 16 AM So the extensive work done by surfacestations com has shown so far that the GISS temperature record for the lower 48 2 of the world according to Hansen is not significantly biased by UHI or microclimate issues Great Science works when skeptics arrive at the same result as proponents However the skeptics seem to have two points that I am still bothered by One is why the NOAA record is so different than GISS especial when factoring the station classification The other is the assertion that the GISS record for the ROW is derived differently and has more significant error sources than the US record Since the ROW record is so important in climate modeling I would like to see some response to the where s waldo posts on ClimateAudit Response NOAA s record is not particularly different from GISTEMP so there is nothing to explain The ROW record is derived similarly to the US except for the rural urban distinction which uses night lights in the US which has been groundtruthed but population in ROW which is the best that can be done at present If you want to know where the global has been warming look at the maps on the GISTEMP website e g this one The answer is all northern hemisphere land masses Australia India etc etc gavin 31 Marion Delgado says 27 Sep 2007 at 12 56 AM In getting back into it one appreciates just how much time is wasted dealing with the most ridiculous of issues Hansen s imagined endorsement of a paper he didn t write thirty six years ago the debunking of papers that even E E won t publish and the non impact of the current fad for amateur photography at the expense of anything substantive In effect if possibly not in intention this wastes a huge amount of people s time and diverts attention from more significant issues at least in the various sections of the blogosphere Serious climate bloggers might all benefit from not getting too caught up in it and keeping an closer eye on the bigger picture We will continue to try and do so here Well put but how do we do it my guess is we have to start by simply not responding to a whole raft of trolls people who aren t making the cut because they don t change what they post even when answered or even refuted 32 Marion Delgado says 27 Sep 2007 at 1 01 AM I think Paulina is right An unnecessary to answer commenter is someone who keeps asking the same question after it s been answered or making the same point after it s been refuted If they are the original asker pointmaker TROLL the process stops No response whatsoever If another commenter was the asker pointmaker UNINFORMED REDIRECT you say asked and answered link or already refuted link and no further answer If they repeat the question or point anyway go to TROLL It s like going on a troll free diet 33 Chris says 27 Sep 2007 at 1 12 AM what was said about the PETM 34 David Graves says 27 Sep 2007 at 1 20 AM I suggest that John Norris might read some Marx or Lenin or Mao to understand the comment about China is hardly Communist Authoritarian yes Communist I don t think so 35 PHE says 27 Sep 2007 at 1 27 AM Does China s aerosol pollution explain why global mean temperature has not risen for the past 8 years or ownly very marginally if you assume 2005 was the warmest 36 SomeBeans says 27 Sep 2007 at 1 49 AM I d like to second or whatever number is appropriate the appeal for more new interesting science and less responding to ridiculous non issues 37 Johnno says 27 Sep 2007 at 2 26 AM China s emissions may reduce sooner than we think due to depletion http www eurotrib com story 2007 5 13 105158 220 This somewhat contradicts assumptions of long term increasing coal use in the IPCC 4th report The potential implications of this are enormous not only for emissions scenarios but global trade 38 pete best says 27 Sep 2007 at 2 39 AM Dear Gavin I am sure that the average professional climate scientists annual carbon footprint is somewhat larger for attending all of these global conferences several times pe annum even if one does take a vacation alongside it BAU seems to be necessary for everyone these days I wonder if the message will ever truely get across to ordinary skeptical citizens of the need to dare I say it reduce carbon expenditure The Tough choices people including scientists need to make are not becomming a reality but maybe soon eh Soon soon soon 39 Florifulgurator says 27 Sep 2007 at 4 50 AM Re 24 Have a look e g at the picture here http www globalwarmingart com wiki Image Short Instrumental Temperature Record png Then STFU 40 roverdc says 27 Sep 2007 at 5 13 AM I found this comment of interest My second thought on China came from travelling through some of the most polluted cites in the world Aerosol haze that appeared continuous from Beijing to Hong Kong is such an obvious sign of human industrial activity that it simply takes your breath away literally In places even on a clear day you cannot see the sun even if there is no cloud in the sky This industrial activity blocks out the sun so why does removing this not result in more global warming Why should this not even be enough to outweigh improvements in co2 output It is interesting to me that given a hundred years of industrialisation it is only now that we are starting to clean up our act with industry that global warming is

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