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All IPCC definitions taken from Climate Change 2007: The Physical Science Basis. Working Group I Contribution to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, Annex I, Glossary, pp. 941-954. Cambridge University Press.

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Comments 88001 to 88050:

  1. Clouds provide negative feedback
    RW1#:46 "it's claimed to take about 100 years to double CO2." Huh? What does that have to do with the rate at which CO2 radiative forcing increases global temperature?
  2. Clouds provide negative feedback
    40, RW1,
    I don't see how this is so. Anthropogenic CO2 forcing is very gradual, taking decades and centuries. Water vapor and clouds act on time scales of hours to days.
    Normal climate change takes millenia. The 0.3˚C swings in global temperature that have been normal for the past two thousand years are not climate change. And clouds have nothing to do with anything. Please begin providing evidence instead of mere assertions.
  3. Clouds provide negative feedback
    40, RW1,
    Actually, when the planet cools (or is cooling), there is more going out than coming in for a while...
    When the planet cools, it radiates less, not more.
    The point is the equilibrium global surface temperature from year to year fluctuates very, very little. This has nothing to do with energy always needing to being conserved.
    No, it doesn't, but it also has nothing to do with clouds. It has to do with the fact that the only mechanism for actual cooling the planet is to either reflect or radiate heat, and the only mechanism for warming is to trap heat. As such, the planet has a fairly stable climate because very little will naturally change the chemical balance of the atmosphere or the albedo of the surface except over very, very long time frames. None of this says that clouds have to be some powerful control knob that keeps everything mellow. The planet stays where it is because it is very, very hard to shift it out of balance (as evidenced by the small changes in climate despite large changes in orbital forcings, except for that perfect case that initiates or terminates an interglacial). You can't say that clouds must be a mitigating factor because you figure they must be. You're going to need much stronger evidence than that.
  4. CO2 effect is saturated
    My apologies to the moderators - I really am giving you a lot of trouble of late.
    Moderator Response: [DB] I've been given worse.
  5. Clouds provide negative feedback
    40, RW1,
    "In AOGCMs, the water vapour feedback constitutes by far the strongest feedback..."
    Water vapor does not equal clouds. The two are very distinct and different. Water vapor involves a GHG effect which is stronger than that of CO2, and is listed in my feedbacks (as H2O).
    The bottom line is a lot of the enhanced warming comes from positive cloud feedback.
    Again, no, clouds come in a distant fourth, at best, behind H2O feedbacks (water vapor), CO2 feedbacks, and albedo feedbacks.
  6. Clouds provide negative feedback
    muoncounter (RE 44), " 'CO2 forcing is very gradual, taking decades and centuries.' Centuries? How do you know that?" Because it's claimed to take about 100 years to double CO2.
  7. CO2 effect is saturated
    novandilcosid @92, I will not dispute the claim that the majority of emissions to space in the range 630 to 710 cm^-1 come from the stratosphere. (I am not agreeing, I am just not disputing.) Certainly it comes from high enough that, as shown in 82 and 86 above, that increasing CO2 concentrations make no difference to the amount of radiation escaping from the troposphere at those wave numbers, which is all that is relevant to this discussion. But those same figures above clearly show that there is a substantial reduction in radiation to leaving the troposphere outside those that range, but between 500 and 850 cm^-1. While you ignore that substantial reduction, your theories are irrelevant. Therefore you need to either accept the values indicated above, in which case we can proceed, or you need to calculate the change in tropospheric radiation at those wave numbers for yourself and show the basis of your dispute with the scientists.
    Moderator Response: [DB] Fixed missing bold closing tag.
  8. CO2 effect is saturated
    novan, I believe I misread your original energy balance comment so you can disregard my subsequent post. I'm not sure what point you're trying to make with post 87 though. I would rather suggest you stick to the topic at hand (CO2 effect saturation and GHG physics) in order to keep your argument clear.
  9. More Carbon Dioxide is not necessarily good for plants.
    villabolo#173: "making deserts and other types of dry land grow." Dry land burns really well. "This is a situation of historic proportions," said Victoria Koenig, public information officer with the Texas Forest Service, in a phone interview with AccuWeather.com Tuesday. "The fuels are so dry. The winds are astronomical. The behavior of the winds is a perplexing situation. It's never been like this before."
  10. Clouds provide negative feedback
    (RE: my #2), "Clouds cover 2/3rds of the surface, so 341 W/m^2 x 0.67 = 228 W/m^2 average incident on the clouds. 79 W/m^2 divided by 228 W/m^2 = 0.34 average reflectivity of clouds. 1/3rd of the surface is cloudless, so 341 W/m^2 x 0.33 = 113 W/m^2 average incident on the cloudless surface. 23 W/m^2 divided by 113 W/m^2 = 0.20 average reflectivity of the cloudless surface. 0.34 - 0.20 = 0.14. 341 W/m^2 x 0.14 = 48 W/m^2 loss for each additional m^2 of cloud cover." There is slight error in this calculation, which I would like to correct for the record. The average reflectivity of clouds is actually about 0.35 (not 0.34), which corresponds to about 51 W/m^2 loss for each additional m^2 of cloud cover instead of 48 W/m^2, resulting in a net loss about 12 W/m^2 instead of 10 W/m^2.
  11. Announcing Shaping Tomorrow's World
    Looks interesting - as much as I find climate science to be fascinating (sometimes in a slow-moving-train-wreck way...), as an engineer I find solutions to the problems even more fascinating. I'll be bookmarking that for sure!
  12. More Carbon Dioxide is not necessarily good for plants.
    Gentlemen; this discussion has been beaten to death. I understand that my illustrations and video, which take up a large segment of my post, concern the productivity of plants under higher CO2 levels. However, it is not the most important issue in a world which would have as low as 500 ppm of CO2. The issue in point #5 is: "5. The worse problem, by far, is that increasing CO2 will increase temperatures throughout the Earth; making deserts and other types of dry land grow. While deserts increase in size, other eco-zones, whether tropical, forest or grassland will try to migrate towards the poles. However, soil conditions will not necessarily favor their growth even at optimum temperatures. This will seriously decrease the amount of land useful for agriculture." (Last sentence recently added.) Of course, we're quite aware of the counter-arguments, made on this thread, concerning "losers and winners". What we should be discussing is whether or not the losers will far exceed the winners. I offer two points in counter-rebuttal to the implicit assumption of this "losers and winners" argument, that the outcome would somehow balance each other. 1. How much land taken out of commission, or substantially reduced in growing ability, will there be by an increase in aridity. This compared to any theoretical increase in abundance in food crops. 2. I believe this has been mentioned before on this thread. What would be the effects of mass migrations and invasions of those lands with 'enhanced productivity' compared to any benefits to the 'blessed' lands or its inhabitants? In my opinion, this would be an effect equaling or, more likely surpassing, any actual benefits; let alone deficits. I will add an illustration to my desertification point for the purpose of emphasizing its importance. I'll also be adding another brief point concerning AGW caused human migration and invasion. In any case, it's time to switch subjects; PLEASE.
  13. More Carbon Dioxide is not necessarily good for plants.
    Wow John D, you still don't get it, do you? The whole *point* of this thread is to show that the impacts of future global warming go well beyond the simplistic "CO2 = more biomass" mantra spouted by the Denialists. No one that I know of here has questioned that, under the right circumstances, enriching the CO2 content of the atmosphere will lead to some increase in *total* plant biomass (not necessarily seed/fruit)-at least in the short to medium term. However, the thing you & your ilk still refuse to accept is that, outside of a controlled environment, an enriched CO2 atmosphere will have a number of negative effects on crop yields-from the impacts of pests & disease, to the impacts of global warming on the activity of Rubisco Activase, to the effects of changed hydrology (droughts & floods). The combined effects of these negatives will almost certainly be enough to offset the straight yield increases garnered from eCO2-especially after acclimation sets in. Now *yes*, maybe some of these negatives can be overcome through the development of new farming techniques-at least in the First World. Of course these measures won't come cheap, & will either send many farmers to the wall or significantly increase the cost of staple food items. Of course, the attitude of you & your ilk is that this is a perfectly good price to pay-so long as the interests of the fossil fuel industry aren't hurt. The rest of us, however, think that it would be much more cost-effective to *not* perform massive experiments on our atmosphere & climatic systems.
  14. A Flanner in the Works for Snow and Ice
    Ken Lambert @87, Just one last time: Taking the data on historical sea ice extent I listed the summer sea ice extent from 1979 to 2008 (the limit of the data). I then took the difference between the 1979 extent and that of each year, and used it to calculate the difference in summer incoming energy flux between that year and 1979. From this, I determined both the average over the period, and the cumulative total for the period, but by summing the values, and by multiplying the mean by 30. The results: Mean difference between 1979 and target year: 0.445 million km^2 Mean additional energy flux compared to 1979: 3.37*10^20 Joules cumulative additional energy flux compared to 1979: 1.01*10^22 Joules Mean additional energy flux for the 2004-2008 mean compared to to 1979: 1.39*10^21 Joules cumulative additional energy flux for the 2004-2008 mean compared to 1979: 6.97*10^21 Joules. Very clearly from your calculation, the value you determine in the quoted section of 87 is the cumulative additional energy in ice melt over the period 1979-2010. That is comparable to the cumulative additional energy flux compared to 1979, or 1.01*10^22 Joules. In contrast, the 1.51*10^21 Joule figure I calculated is comparable to the Mean additional energy flux for the 2004-2008 mean compared to to 1979, or 1.39*10^21 Joules. It differs slightly because it is calculated for an approximate average of the years 2006-2010 rather than 2004-2010, and also because it is compared to an approximate average of 1979-2003 (which has slightly more ice than 1979 itself). I do not know how I could possibly be clearer than I have been in this post. Therefore if you persist with the absurdity that the difference in energy flux over a season is the difference in energy flux over 32 years, there is no further basis for debate between us.
  15. Clouds provide negative feedback
    RW1#43: "CO2 forcing is very gradual, taking decades and centuries." Centuries? How do you know that? See the thread 40 Year Delay, which suggests that the thermal inertia of the oceans results in a lag to full warming from CO2 forcing on the order of 40 years.
  16. novandilcosid at 10:25 AM on 20 April 2011
    CO2 effect is saturated
    Tom Curtis wrote at #82: "It is odd that novan concentrates his discussion on the 650 wave number. It is well known that at that wave number, CO2 absorption is at its peak, and that as a result the majority of CO2 emissions to space at that wavenumber come from the stratosphere." Actually my calculations were not for the Wavenumber 670 region (indisputably stratospheric) but used the table values for wavenumber 650. [There are two ways to interpret this table, as it lists absorption rates through different gas depths at 50 wavenumber intervals. So either the table value is a spot measurement, or it is an average across the 50 wavenumber band centred on the tabled value. Either way it does not invalidate the conclusions.] I took a standard line and decremented it iteratively using the amplitude at each frequency as an attenuation factor, checking at each iteration for the total remaining power. In this way I was able to replicate the table absorptions at STP. I then had the number of iterations per atmcm of CO2. I then repeated the exercise at altitude, altering the shape of the absorption line (it gets peakier but narrower with altitude) to see what happens. I found that at wavenumber 650 (not 670) the emissions to space are mostly from the stratosphere. Emissions from the troposphere are not totally extinct but are only a small fraction of the spacebound photons in that band. We should not lose sight of the fact that over 10% of the atmosphere lies ABOVE the Tropopause (8% in the region 35N to 35S, 20% at higher latitudes). In the strong emission/absorption CO2 band from wavenumbers 625 to 725 most emissions are coming from above the Tropopause.
  17. novandilcosid at 10:02 AM on 20 April 2011
    CO2 effect is saturated
    e's claims at #90 above are erroneous. His second equation should read: Change in Back Radiation = Change in Surface Radiation + Change in Evaporation. The Surface Balance equation can be rewritten: Absorbed Solar = Net Surface radiation into the atmosphere + Net Surface Radiation through the window to space + Convection + Evaporated water (latent heat). Writing this in terms of change, and making the (only slightly wrong) assumptions that changes to Absorbed Solar, Conduction and Net Surface Radiation through the window to space are zero, then yes indeed Net Surface radiation into the atmosphere = -Evaporated water (latent heat). This is another way of saying two things: 1. The energy transported from the surface always equals the insolation. Unless the solar constant or the albedo change, the energy from the surface is a constant. 2. As the Greenhouse tightens we expect the back-radiation to increase at a greater rate than the surface radiation: the radiative balance between the atmosphere and the surface narrows. At a perfect greenhouse, the retransmission of energy from the GHGs would be from the first layer of molecules - no temperature difference, perfect black body so total balance. The relative increase in back radiation allows the surface temperature to rise. This rise increases the evaporation rate in such a way that the relative increase in back radiation balances the increased evaporation. Note that the heat transport into the atmosphere from the surface is approximately Conduction one fifth Net Radiation one fifth Evaporation three fifths If the temperature increases, evaporation goes up and net radiation goes down. The rate at which evaporation increases with temperature is in dispute - essentially it is unkown. Measurement suggests 5% per DegC. The modellers use 2.5% or less. Additionally relative humidity is often taken to be constant. Measurement suggests that this may be abrave assumption.
  18. Muller Misinformation #4: Time to Act
    "I think he's just inflating uncertainty in the style of Judith Curry." The uncertainty argument gets flipped on it's head, and in this instance especially. It is our uncertainty surrounding sensitivity and aerosols and UHI (which, I believe he is looking at differently than others) that make the statement about 'having time' so wrongheaded. His study is merely another thermometer, has no attribution modelling, AFAIK, and doesn't really speak to how each degree of temperature rise changes the planet, or each W/m2 of forcing changes the energy that drives the atmospheric systems or how heat effects the hydrological cycle, etc. Those are the realities that we will be dealing with, not numbers on a stick. Our policy time table will be set by real-life effects because policy is about real people, what we value, and how willing we are to put what we value at risk.
  19. Clouds provide negative feedback
    KR (RE: 35), "And don't forget the speed of change of anthropogenic forcings, primarily CO2. Which is changing faster than any of the other forcings, in fact faster than all the other forcings are changing combined." I don't see how this is so. Anthropogenic CO2 forcing is very gradual, taking decades and centuries. Water vapor and clouds act on time scales of hours to days.
  20. A Flanner in the Works for Snow and Ice
    Tom, just read this aghain and see if you can understand it. The numbers are form Dr Trenberth's papers. "In the same 31 year period you are calculating 15.1E20 Joules - roughly half the Trenberth cumulative figure. In that period (31 years) assuming that Trenberth's global imbalance was something between 0.5 and 0.9W/sq.m (say 0.7W/sq.m average) or 112E20 Joules/year for 31 years, then the Earth would have accumulated 31 x 112 = 3472E20 Joules of extra heat energy."
  21. Clouds provide negative feedback
    Sphaerica (RE: 36), "There is none. There doesn't have to be. Insolation is 290W/m2. The planet radiates 290W/m2. Everything (normally) stays in pretty good balance as easily as that. But the bottom line is 290 in, 290 out." I know energy has to be conserved (energy in = energy out) - that isn't the point. The point is the equilibrium global surface temperature from year to year fluctuates very, very little. This has nothing to do with energy always needing to being conserved. "If the temperature of the planet appears to cool, then there is less out for a while. This can only go on for only so long before it catches up and the balance is restored." Actually, when the planet cools (or is cooling), there is more going out than coming in for a while, but think you're confusing equilibrium being restored and temperature being restored. They are two totally different things.
  22. Muller Misinformation #4: Time to Act
    Thanks Dana. This sentence in particular grabbed me, "If we could just flip a switch and turn off greenhouse gas emissions, we would have a lot more time." If I may restate the obvious: Following the work of Hansen, Tripati, Arora, and others, we are already on thin ice with the warming yet to come. It may not be practical to replace FF use entirely for decades. During this time more warming backlog will be created. The lag inherent in the system creates a terrifying delay between our actions and their consequences. It's terrifying because there just are not enough long-term thinkers in the world. Hmm, I wonder if there is a correlation between cultures with a higher propensity to consume (indicative of short-term thinking) and cultures with a reluctance to take corrective action on climate change.
  23. Christy Crock #4: Do the observations match the models?
    rhjames @40, I noticed that you simply dismissed the numbers and information I gave you (oh well, hopefully someone else took something away from my efforts), and launched into making yet more unsubstantiated, unquantified and baseless assertions. "This is the approximate time that models have been predicting climate." Really, interesting, please demonstrate that. I could help, but I am trying to encourage you to make more of an effort. "I can't say that real data is convincingly supporting the predictions of models, to the extent that I would rely on them" That is your opinion, as has been demonstrated, the data suggest otherwise. "I don't think predictive models have been around long enough to get excited about them." Again, your opinion, and a strawman. Could you please support your assertion with some facts. And you still have not answered this relevant question posed to your earlier: "Can we assume that you agree with Christy's misinformation then?"
  24. Clouds provide negative feedback
    Sphaerica (RE: 37), "To me, your theories are the ones that require an awful lot of coincidences." Which ones and why? "You should also avoid referring to "AGW theory." There is no such thing. There is a GHG theory, which is a proven fraction of climate science. There is all of climate science, which is advancing and changing every day. There is no single "AGW theory," and attempts to cast it as such are merely backhanded attempts to imply that there's something simple there that can easily be ignored or dismissed." Sorry for the confusion. When I refer to the "AGW theory", I just mean the catastrophic or enhanced warming of around 3C predicted by the models, the IPCC, etc. That's all.
  25. 2nd law of thermodynamics contradicts greenhouse theory
    e 999 You said: “Nothing is changing if input and output are the same. Using your terms, you are looking for the point in time when AU = I.” See 1004. You said: “These two models are describing the system in very different ways, and cannot be mixed and matched in the simple fashion you are attempting.” Maybe, but only to the detriment of the GHG physics. The slab model only works with ε= 1, ok then what good is the model? If effective emissivity is not demonstrable then what good is it? If ee is only to be plugged Stefan-Boltzmann law, it is only conjecture. As I mentioned to KR, a semi- transparent filter with ε=.612 will not function GHG physics proclaims. That is, will 240 W/m^2 incident on filter with ε=.612 will increase the incident to 390 W/m2 while radiating 240 W/m^2 originally incident...NO.
  26. Christy Crock #4: Do the observations match the models?
    About "Bender et al, 2006". Cited by 3 (Google Academics): Investigation of Regional and Seasonal Variations in Marine Boundary Layer Cloud - Properties from MODIS Observations, by Jensen, Vogelman, Collins, Zhang and Luke: " the albedo of subtropical MBL clouds is poorly simulated by climate models (Zhang et al. 2005; Bender et al. 2006)." Relating Satellite-Observed Cloud Properties from MODIS to Meteorological Conditions for Marine Boundary Layer Clouds, (same authors): "Marine boundary layer (MBL) clouds have a strong shortwave cloud radiative forcing on the earth’s climate system (Klein and Hartmann 1993).... However, their simulation in global climate models (GCMs) is among the most problematic, and few models can simulate the extent of these clouds (Ma et al. 1996; Siebesma et al. 2004) or their albedos realistically (Zhang et al. 2005; Bender et al. 2006)." and Robert Johnston's website, with this quote: "Recent studies have suggested notable changes in the Earth's total albedo, or reflectance (Qiu et al., 2003; Palle et al., 2003; Palle et al., 2004; Wielicki et al., 2005), which would mostly result from changes in cloud cover. Other research indicates trends in cloud cover, which could have increased absorption of solar radiation since the 1980s (Sun and Grossman, 2004; ISCCP, 2006). It is understood that clouds are poorly handled in current GCMs (Potter and Cess, 2004). Recent comparisons suggest that GCMs may be biased towards more warming by overestimating the Earth's albedo (Bender et al., 2006)." [The "towards more warming" is on Johnston, not Bender's] AND THAT'S IT. What do you think of Johnston's "GCMs may be biased towards more warming by overestimating the Earth's albedo"?
  27. Christy Crock #4: Do the observations match the models?
    Albatros - you criticize me for cherry picking the last 15 years. This is the approximate time that models have been predicting climate. In examining the models, I want to compare their predictions with real data. In other words, I want to use predictions from models made some years ago, and compare them with what actually happened. If you can show me models that did this more than 15 years ago, I'm happy to go back further. All I'm really saying is that at this stage, I can't say that real data is convincingly supporting the predictions of models, to the extent that I would rely on them. Let's look at what the models predicted 10 years ago and look at the following 20 years. If they perform (whether it be heating or cooling)over the 30 year period, then we will have something worthwhile. I don't think predictive models have been around long enough to get excited about them.
  28. funglestrumpet at 08:52 AM on 20 April 2011
    Muller Misinformation #4: Time to Act
    Dana1981 @ 6. I am well aware that the skeptics' position is not realistic, but all this 'It is anthropogenic - no it isnt' business only serves to delay the urgent action so obviously needed. As far as I am concerned global warming almost certainly is anthropogenic in origin; either that, or the rise in atmospheric CO2 being in line with the increase in fossil fuel consumption is one big coincidence that also confounds isotopic analysis. BUT if you look at the debate on this site and also Dr Muller's argument (and of those like him), the need to tie it or untie it to mankind seems to outweigh the much more important consideration of the need for urgent action. Consider an imaginary situation where we had been producing the current volume of CO2 for centuries, but global temperatures had only recently begun to rise. In those circumstances very few would argue with the IPCC when it concluded that the temperature rise was not anthropogenic in origin. There would still be vested interests that would want business as usual, but they would have a much harder time rabble rousing than they do at present. Would we as a species take a 'What will be, will be' approach because it is not anthropogenic in origin, or, knowing what we know about the greenhouse effect, would we cut our production of CO2 in order to counter whatever actually was the cause; that, and a whole lot of planning should the situation deteriorate in line with scientific predictions. I rather think we would take the latter route and p.d.q. So, let’s forget about who, or what the heck, is causing the current warming, even though we are as near to certain as makes no difference and realise that waiting while we completely resolve the origin is a luxury we cannot afford. Surely no one intellectually above that of the lesser spotted wood lice is going to believe that the current warming is going to reverse when there are no cycles that fit the observed long-term trend. (And yes, I am aware of Lord Lawson’s point of view, but I have the advantage of living in a country at time when he was in government and his policies as Chancellor of the Exchequer all went pear shaped. (Yes, history does repeat itself.)) We should challenge the sceptics refusal to act and if they argue that reversal is imminent, we should demand robust scientific evidence in support. Heaven knows there is enough robust scientific evidence on this side of the fence.
  29. 2nd law of thermodynamics contradicts greenhouse theory
    Tom Curtis 998 I don't agree with your simplified Entropy calculations/equations. However, more problematic is your “equilibrium” condition from which you start. That is, prior to radiating 480W/m^2 the earth is limited by SW input. It is how temperature is increased beyond the solar input which is at question. As I was trying to explain with my Teqreference, 240 W/m^2 SW absorbed by the earths surface results in surface radiation of 240 W/m^2 LW. Because the atmosphere in your example is a blackbody, all 240 W/m^2 of terrestrial radiation is absorbed...atmosphere flux 240W/m^2 equates to 255K. Now as you said, “ with an atmosphere at 255 K, it will radiate 240 w/m^2 to space and 240 w/m^2 towards the surface. It follows that there is no violation of conservation of energy, and I did not double count.” Ok Tom, if you didn’t double count, and the system is in equilibrium, then back radiation is not physical. GHG physics can not have it both ways either: 1) the simple slab model atmosphere absorbs all terrestrial radiation and is therefore the overall system is at equilibrium when terrestrial emission reaches 240 W/m^2 OR 2) the simple slab model atmosphere transmits half the terrestrial emissions and absorbs half. The slab then re-radiates up and down...surface temperature increases until total outgoing radiation is equal to 240 W/m^2...surface temp 255K.
  30. Clouds provide negative feedback
    Sphaerica (RE: 38), 'A very large amount (if not most) of the enhanced warming from the climate models comes from positive cloud feedback.' "This is not true. Citation, please." Here "In AOGCMs, the water vapour feedback constitutes by far the strongest feedback, with a multi-model mean and standard deviation for the MMD at PCMDI of 1.80 ± 0.18 W m–2 °C–1, followed by the (negative) lapse rate feedback (–0.84 ± 0.26 W m–2 °C–1) and the surface albedo feedback (0.26 ± 0.08 W m–2 °C–1). The cloud feedback mean is 0.69 W m–2 °C–1 with a very large inter-model spread of ±0.38 W m–2 °C–1 (Soden and Held, 2006)." "In the idealised situation that the climate response to a doubling of atmospheric CO2 consisted of a uniform temperature change only, with no feedbacks operating (but allowing for the enhanced radiative cooling resulting from the temperature increase), the global warming from GCMs would be around 1.2°C (Hansen et al., 1984; Bony et al., 2006). The water vapour feedback, operating alone on top of this, would at least double the response.[6] The water vapour feedback is, however, closely related to the lapse rate feedback (see above), and the two combined result in a feedback parameter of approximately 1 W m–2 °C–1, corresponding to an amplification of the basic temperature response by approximately 50%" When you factor in that the water vapor and lapse rate feedback are tied directly together and serve to directly offset each other, the net effect of the cloud feedback, with some of the models at least, becomes as significant - if not more so: "Because the water vapour and temperature responses are tightly coupled in the troposphere (see Section 8.6.3.1), models with a larger (negative) lapse rate feedback also have a larger (positive) water vapour feedback. These act to offset each other (see Box 8.1). As a result, it is more reasonable to consider the sum of water vapour and lapse rate feedbacks as a single quantity when analysing the causes of inter-model variability in climate sensitivity." The bottom line is a lot of the enhanced warming comes from positive cloud feedback.
  31. Muller Misinformation #4: Time to Act
    I have responded to Gilles' trolling comments about Fossil Fuels on a more appropriate thread. My concluding remarks were:
    "Now, I am perfectly happy to get into the nitty-gritty of this subject with Giles - but only on the condition that he restrict the discussion exclusively to this appropriate thread. If he discusses it anywhere else, except by a simple link back to this thread in other partially appropriate threads (and only in such partially appropriate threads), then I will withdraw from the discussion here as well. I will adopt the principle of not feeding the troll, unless he shows he is not a troll by not trolling other threads. I strongly recommend that other commentators follow the same strategy. I also strongly recommend that the moderators cease telling us to not feed the troll. If you need to tell us that, the troll is trolling and their trolling comments (and any replies) should simply be snipped with a link the appropriate thread for discussion provided. The current moderation policy is simply asking for denier talking points to remain continually unanswered on every thread that is generated - which is unacceptable. So, now it is over to Gilles (and the moderators). I look forward to the discussion."
    I believe that represents they suggest the appropriate strategy for dealing with Gilles' trolling.
    Moderator Response: [mc] fixed link
  32. CO2 limits will harm the economy
    Gilles has argued that it cannot be both easy and difficult to give up fossil fuels at the same time. As dana has pointed out, that is a strawman argument. It has not been argued that it is easy to give up fossil fuels, but rather that it is technically feasible, and beneficial to do so. By technically feasible, we mean that there is no impediment from physics to doing so - so I guess at a stretch, we could say it is "physically easy", so in this sense, and understood only in this way, it is "easy" to give up fossil fuels. But, this does not even mean that it is technically easy. Going from physics to a usable technology is not always a straight forward path. In the case of fossil fuels as fuels, their use in transport is particularly difficult to find a technically equivalent alternative to using fossil fuels, although there are already many technically adequate alternatives. Transport ships, for example, could use a combination of wind power (sail) and solar power with battery storage to make any trip they currently make - but would take significantly longer to do so (though not more than three times longer). That is a technically adequate solution. Our civilization could operate on that basis, and probably at an advantage economically when the additional shipping cost implied is defrayed against the reduced cost of not needing to ship a torrent of fossil fuels. Business and political communication needs can be adequately substituted for by a combination of high speed internet connections for very fast virtual meetings using Skype equivalents, and solar powered Zeppelins for air transport. Again the transport times will significantly increase, but economic and political costs need not do so in tandem if we adjust behaviour to match what is now technically feasible. Of course, what is not technically feasible at the moment is eliminating fossil fuels while retaining our SUV driving, one person per car, traffic jam loving culture. A switch away from fossil fuels in the short term is going to require significant cultural changes. Not changes in those core parts of western culture that has made our civilization great, of course, but in some of those aspects of our culture which have grown up since the 1950's based on the assumption of an endless supply of cheap fossil fuels. So, this means that while fossil fuels are physically easy (in the strict sense defined above) to replace, they are culturally difficult to replace in the short term. You can easily extend the pairing of easy/difficult juxtapositions: It is physically easy, but psychologically difficult; It is physically easy, but institutionally difficult; It is physically easy, but economically difficult (in one of several possible meanings of that term). In fact, this easy/difficult juxtaposition is very easy to extend, but while rhetorically gratifying in showing that Giles knows so little about what he talks - that he is big on factoids but low on wisdom - it is not profitable. Now, I am perfectly happy to get into the nitty-gritty of this subject with Giles - but only on the condition that he restrict the discussion exclusively to this appropriate thread. If he discusses it anywhere else, except by a simple link back to this thread in other partially appropriate threads (and only in such partially appropriate threads), then I will withdraw from the discussion here as well. I will adopt the principle of not feeding the troll, unless he shows he is not a troll by not trolling other threads. I strongly recommend that other commentators follow the same strategy. I also strongly recommend that the moderators cease telling us to not feed the troll. If you need to tell us that, the troll is trolling and their trolling comments (and any replies) should simply be snipped with a link the appropriate thread for discussion provided. The current moderation policy is simply asking for denier talking points to remain continually unanswered on every thread that is generated - which is unacceptable. So, now it is over to Gilles (and the moderators). I look forward to the discussion.
  33. Muller Misinformation #4: Time to Act
    BillyJoe - From everything I can tell, the posters here spend quite a bit of effort attempting to educate skeptical participants. However, when said skeptic refuses to read the evidence they are pointed to, repeats errors that have already been pointed out with no more than an "I don't think so", and even contradicts themselves to keep the argument going - well, then they are not interested in learning, only arguing. As to off-topic - every time someone raises an off-topic point, they are directed to where the question/data/argument is relevant. That way discussion of particular issues are concentrated to where interested readers can find them, not scattered about the website. But again, when that poster persists in doing this over and over and over despite requests? What should the moderators do? I would love to hear a good idea in that regard. You can lead a horse to the data - but you can't make it read the references...
  34. Muller Misinformation #4: Time to Act
    Billy @31, You raise some valid points, but I have to take issue with you on one of them: " Instead you could educate them - and others, like myself, who are just getting a grasp on the complexities of climate change. " Trolls are simply not open to having their minds changed or learning. That is a fact. And by trolling, and driving posts off topic and obfuscating, it inhibits SKS and the more knowledgeable posters here for educating and informing others. It also creates an unpleasant environment that also deters people from hanging around and/or contributing and learning in the process. To my knowledge only one person has been "banned" from posting here at SkS, and IMHO, that decision was completely justified and probably made for the safety of people posting at SkS. It is a bit of a conundrum. But there have been quite a few genuine trolls here of late and Gilles is one of them. I must admit though, I have learnt an awful lot chasing down and refuting the misinformation and distortion that 'skeptics' seem so fond of disseminating. I'm curious to which off-topic SkS article you are referring to. Anyhow, my suggestion would be to voice your concerns directly to John Cook by email-- as you know he is an incredibly nice and reasonable person, and he will value your input. Moderators feel free to delete, maybe after Bill has acknowledged reading my post?
  35. Muller Misinformation #4: Time to Act
    Oops, it looks like Albatross provided the RealClimate link as I was typing my previous post.
  36. Muller Misinformation #4: Time to Act
    When skeptics raise uncertainty as a justification for inaction it is often revealing of their bias, since they typically emphasize uncertainty on only one side of the probability curve. For example, did Dr Muller consider that the human contribution to the observed warming might be larger than 100%, which would be possible if some unknown natural forcing in the twentieth century had a cooling effect? (I recall that RealClimate had a recent post that gave a range for the human influence that had an upper range of above 100%, but I can't find the reference.) If so, then we're in an even bigger rush.
  37. Muller Misinformation #4: Time to Act
    Re Muller's statement on how much of the warming can be attributed to GHGs. This is what Dr. Gavin Schmidt had to say back in late 2009. Caveat emptor, his comment was posted on a blog, but is strongly suggests that if Muller listen to people in the know, then we are indeed in a rush to take action. "Over the last 40 or so years, natural drivers would have caused cooling, and so the warming there has been … is caused by a combination of human drivers and some degree of internal variability. I would judge the maximum amplitude of the internal variability to be roughly 0.1 deg C over that time period, and so given the warming of ~0.5 deg C, I’d say somewhere between 80 to 120% of the warming. Slightly larger range if you want a large range for the internal stuff." Does Muller cite any substantive and credible scientific evidence to support the claim that only < 50% of the observed warming may be attributable to elevated GHGs from burning of fossil fuels? If he is just musing then that is not scientific or constructive. And it is certainly not a smart strategy to base policy and action on such a serious matter based on wishful thinking. Oh, hello Rob @30, fancy running into you here ;)
  38. Muller Misinformation #4: Time to Act
    Muller seems to me to have confidently expected to verify the "concerns" of Anthony Watts and others. Having been disappointed he is now casting around, a bit desperately, for another raison d'etre. He seems now to be set upon investigating climate sensitivity and human attribution, which were not part of BEST's original remit. Hell, but his daughter is program manager! He can do what he likes. I suppose he is not the first to change the goalposts, and hope the funders are ok with it.
  39. Muller Misinformation #4: Time to Act
    A point about so called trolls and off-topic comments. Because of the tendency to call anyone who disagrees a troll, this blog risks becoming place where like minded people come to be massaged. This is not healthy. From my own point of view, I have derived great benefit from having the errors of the so-called trolls exposed by the more knowledgable posters here. The irony is that most topics here are about refuting just such false information by prominent climate sceptics, so it seems strange to ban posters who hold these same false views. Instead you could educate them - and others, like myself, who are just getting a grasp on the complexities of climate change. Otherwise you come off looking like you cannot provide the answers or you have something to hide. As for off topic comments: Most off-topic comments merely enlarge on a topic rather than detract from it. For learners like myself that is very useful. Moreover, no one has yet come up with an off topic comment that comes anywhere near rivalling that of a certain article written here a few weeks ago which was about as far off topic as you could possibly go for a blog called Skeptical Science.
    Moderator Response: [muoncounter] It is not at all correct to say that anyone who disagrees is called a 'troll.' That designation is reserved for those who seek to provoke off-topic distractions, knowingly raise strawmen just for the sake of provoking argument, routinely exercise in Gish Gallop or other rhetorical tactics that are devoid of content, etc. This is not a court of law: without facts to support an argument, one who exercises the lawyerly practice of arguing the argument earns the name 'troll.'
  40. Christy Crock #4: Do the observations match the models?
    @Berényi Péter #37 So your epistemology doesn't reject my model and roughly the epistemological path proposed is accepting or rejecting a model depending on who did it or whether it was included in some other work? The first 6 models in your conjunction pretty much coincide with ERBE and don't exclude each other in one sole backwards rendition of one dependent variable. The first 11 models in it match ERBE al least in the queues. So if the AR included just 11 models your objections would be less, and if it included 6 models, your words fall [It all indeed does to what really is in Bender's]. So 20 models are not included to provide the widest variety of approaches and to illustrate the state of the art of something but just to show redundantly the clumsiness of what is behind so the Berényi Péters of the world can shine, even when they descend to the use of pictures? Your "conclusions" are too much dependent on keeping control on which is included in the story and how the story is told. Add just marshmallows and a bonfire.
  41. More Carbon Dioxide is not necessarily good for plants.
    orchestia at 06:32 AM, what you say is right, unfortunately the faith that technology will overcome many of the challenges for agriculture is not shared by those who only see doom and gloom. The debate on whether CO2 has a fertilisation effect on plant growth has advanced considerably. Whereas not so long ago many would not accept that it was real, despite evidence of it having being used commercially for decades, or the evidence shown by results of the FACE trials. Most do now concede that it is not only real, but results in quite significant improved growth. However many who now have no other argument and must accept it as real, now focus on other aspects such as availability of nutrients, pest and diseases, or the ability of plants to adapt With regards to the pests and diseases, they must somehow think that the rapid and ongoing research that has allowed the spectacular advances so far is suddenly going to stopped, that science is suddenly going to enter a new dark age. I don't share that pessimism. When they focus on nutrient availability, it seems that most of their concerns is about nitrogen based fertilisers which seems ludicrous given there is an almost unlimited supply that again technology is helping to improve access to. I do however have concerns for the supply of the likes of phosphorous, potassium, sulphur etc as nature does not provide any natural replenishment and our wasteful lifestyle is wilfully squandering about half of what is required to produce the food that sustains them. However with the will, technology will help over come some this also. Isn't it amazing the lengths that people go to recycle things that aren't so essential, newspapers, soft drink cans and bottles, but ignore the basic nutrients essential to life.
  42. Christy Crock #4: Do the observations match the models?
    Alec @34, "I'll be developing these three points in different comments during the next 24 hours or so. Please, collaborate in clearing this up and don't follow the path proposed by this person." Look forward to that Alec. I'll collaborate how and when I can. In the meantime, Re the claim, "Basically the same set the IPPCC AR4", IIRC that is not true. Re the claim, "it turns out not even error bars for model outputs overlap.", a look at the graphic shows that assertion to be false.
  43. Rob Honeycutt at 07:16 AM on 20 April 2011
    Muller Misinformation #4: Time to Act
    Gilles @ 27... But the arguments that you are putting forth ensure that we will not overcome. Again, this all comes down to risk management. If you're 90% sure of a bad outcome you don't hem and haw about whether to take action. You have to act. I'm continually surprised by the notion that acting is going to cause terrible harm to the world economy. There is very little to support that argument. On the contrary there is every reason to believe it will improve the economy much in the way that WW2 laid the groundwork for the prosperity that followed the war. AND, a war is a destructive act with many years of clean up that follows. Addressing climate change would be a constructive act, no clean up required.
  44. Stephen Baines at 07:09 AM on 20 April 2011
    Muller Misinformation #4: Time to Act
    "usually what's difficult is not sure to be overcome" Which is why the availability of reasonable alternatives we can work toward is relevant...it makes the difficult possible. You see? By emphasizing only one side of uncertainty envelope regarding human effects on climate and engaging in yet another evaluation of climate science, Muller is effectively delaying a change that will take time to implement. He is worried about attribution past climate change to humans. However he should also be worried, were he objective, about the risks associated with delays in action should he find the human contribution is dominant, as is very likely.
  45. Berényi Péter at 07:02 AM on 20 April 2011
    Christy Crock #4: Do the observations match the models?
    #36 Alec Cowan at 03:52 AM on 20 April, 2011 So, your approach admits 1) Gilles, RSVP, Ken Lambert or yourself developing models now, in 2015, in 2025, or in 2040 which will predict an albedo of 0.5 for 1985-89 so it will always be impossible to use a model in any sense as a considerable difference will subsist. Is it really necessary to obfuscate? I am talking about the twenty computational climate models considered by Bender et al. Basically the same set the IPPCC AR4 report relies on.
  46. Muller Misinformation #4: Time to Act
    My understanding is that 100% of the warming since the late-19th Century is anthropogenic. There was a small natural warming influence in the first half of the 20th Century but it was offset by a natural cooling influence of approximately the same magnitude in the second half of the 20th Century, which means that all of the temperature difference between late-19th Century and today (around 0.8°C) is due to human influences. This is based on data presented in: Combinations of Natural and Anthropogenic Forcings in Twentieth-Century Climate - Meehl et al http://www.cawcr.gov.au/bmrc/clfor/cfstaff/jma/meehl_additivity.pdf
  47. Muller Misinformation #4: Time to Act
    "Yes, because everything which is difficult is also impossible. Stellar logic."" No - usually what's difficult is not sure to be overcome, only. So you must also take into account this possibility.
  48. More Carbon Dioxide is not necessarily good for plants.
    Plant production is often limited by local exhaustion of carbon dioxide, an essential nutrient, in the immediate vicinity of photosynthesising leaves during calm periods of bright sunshine. Windy countries, such as mine, have an advantage here. Furthermore, there is plenty of evidence that the maniac photosynthetic rate of most plants (why this is so isn't known - it is up to 10X that required) causes global depletion of carbon dioxide for no good purpose. A great number of studies have shown that increased carbon dioxide content stimulates plants. I know of no study that shows "harm" to plants from increased CO2 - there is diminution once the concentration reaches very high levels, but harm, no. I have read recent reports stating that the higher levels of CO2 at present are resulting in greater primary production - not less. As for running out of nutrients - we may be, though that is not established. At present we use extract the plant nutrients we need form concentrated sources, such as mineral rich deposits. However, as need arises we will obtain them from dispersed sources, such as the ocean. The technology already exists to do much of this. It has to be borne in mind that there is no less of any element in existence today. Each is cycled in geological time. Our technology will be able to circumvent this in the future and greatly increase the rate of recycling and reuse. The water issues are ones of misuse and misallocation, rather than overuse. If we give up scientific farming (which has increased production on most US farms by 300% in a lifetime) then people will have to starve. Between 1 B and 3 B will have insufficient food. Do the Greens want that? I don't. Let's find good scientific and technical solutions to our problems, and not rely on unsubstantiated polemic.
  49. Stephen Baines at 06:16 AM on 20 April 2011
    Muller Misinformation #4: Time to Act
    About Muller... My test of objectivity rests on the point that Tom made...if anyone is going to talk about uncertainty regarding the effect of humans on climate change, they have to acknowledge uncertainty at both high and low ends. To the extent that Muller emphasizes the low end and the tendency for human impacts to be exagerrated rather than underestimated, he fails to be objective. He is buying into a narrative about the intentions of scientists (they never talk about uncertainty, they are advocates etc) a priori based on hearsay rather than taking a neutral position and focusing on the data and the reported research. That's just not very skeptical, IMO.
  50. Muller Misinformation #4: Time to Act
    Which observation? Off the top of my head (I probably missed some)... Winters warming faster than summers, nights warming faster than days, poles warming faster than tropics, troposphere warming while the stratosphere cools, increase in downward long wavelength radiation from the night sky, decrease in long wavelength radiation leaving the top of the atmosphere. All of these are exactly analogous to the effect you would see if you were to increase the insulation on a house in a cool climate without adjusting the heating. Thus all of these indicate that the recent warming is due to an increase in the heat trapped below the stratosphere - which we call the greenhouse effect.

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